pollen coat

A layer of extracellular matrix deposited onto the surface of the pollen wall upon disintegration of the tapetal layer of the anther wall in the late stages of pollen development. The composition of this material is highly heterogeneous and includes waxes, lipid droplets, small aromatic molecules, and proteins. The pollen coat is proposed to have many functions, such as holding pollen in the anther until dispersal, facilitation of pollen dispersal, protection of pollen from water loss and UV radiation, and facilitation of adhesion of pollen to the stigma.


mineralized extracellular matrix

biolink:GrossAnatomicalStructure biolink:AnatomicalEntity biolink:OrganismalEntity biolink:BiologicalEntity biolink:NamedThing biolink:Entity biolink:PhysicalEssence biolink:SubjectOfInvestigation biolink:ThingWithTaxon biolink:PhysicalEssenceOrOccurrent

Extracellular matrix that is mineralized.


vitelline envelope

biolink:CellularComponent biolink:AnatomicalEntity biolink:OrganismalEntity biolink:BiologicalEntity biolink:NamedThing biolink:Entity biolink:PhysicalEssence biolink:SubjectOfInvestigation biolink:ThingWithTaxon biolink:PhysicalEssenceOrOccurrent

A glycoprotein-based structure that lies outside the plasma membrane and surrounds the egg before fertilization.


adhesive extracellular matrix

A extracellular matrix which attaches an organism to a substrate.


ATG2-ATG18 complex

A protein complex essential for autophagy during nutrient deprivation, a catabolic process that sequesters undesired cellular material into autophagosomes for delivery to lysosomes for degradation. Contributes to nutrition homeostasis and damage control in eukaryotic cells. Functions at a late step of autophagosome formation for efficient completion of sequestration, probably through facilitating recruitment of ATG8-phosphatidylethanolamine (PE) to the preautophagosomal structure (PAS) and/or its protection from deconjugation by ATG4. Composed of ATG2 and ATG18 in Saccharomyces cerevisiae.


elongin complex

A transcription elongation factor complex that suppresses RNA polymerase II pausing, and may act by promoting proper alignment of the 3'-end of nascent transcripts with the polymerase catalytic site. Consists of a transcriptionally active Elongin A subunit (about 100 kDa) and two smaller Elongin B (about 18 kDa) and Elongin C (about 15 kDa) subunits.


Schwann cell microvillus

Small finger-like extension of a Schwann cell that contacts the nodal membrane.


inner dense plaque of desmosome

The desmosomal part containing the C-termini of desmoplakins which interact with the keratin intermediate filaments, serving to tether the intermediate filaments to the plasma membrane.


kinetochore

A multisubunit complex that is located at the centromeric region of DNA and provides an attachment point for the spindle microtubules.


mitochondrion-derived vesicle

A vesicle derived via budding from a mitochondrion. These vesicles often contain inner membrane and, much more rarely, cristae.


intracellular vesicle

Any vesicle that is part of the intracellular region.


post-lysosomal vacuole

A membrane-bounded intracellular vesicle formed late in the endocytic pathway when the pH in the vacuole becomes neutral prior to exocytosis.


platelet alpha granule

A secretory organelle found in blood platelets, which is unique in that it exhibits further compartmentalization and acquires its protein content via two distinct mechanisms: (1) biosynthesis predominantly at the megakaryocyte (MK) level (with some vestigial platelet synthesis) (e.g. platelet factor 4) and (2) endocytosis and pinocytosis at both the MK and circulating platelet levels (e.g. fibrinogen (Fg) and IgG).


piccolo-bassoon transport vesicle

A cytoplasmic dense-core vesicle that transports a range of proteins including piccolo, bassoon, N-cadherin and syntaxin. The transported proteins may be associated with the external side of the vesicle, rather than being contained within the vesicle, therefore forming an aggregate of vesicle and proteins. Piccolo-bassoon transport vesicles (or PTVs) range in size from approximately 80 nm in diameter for dense core vesicles to 130 nm by 220 nm in area for aggregates. They are packaged via the trans-Golgi network before being transported through the axon.


secretory granule

A small subcellular vesicle, surrounded by a membrane, that is formed from the Golgi apparatus and contains a highly concentrated protein destined for secretion. Secretory granules move towards the periphery of the cell and upon stimulation, their membranes fuse with the cell membrane, and their protein load is exteriorized. Processing of the contained protein may take place in secretory granules.


merozoite dense granule

Electron-dense organelle with a granular internal matrix found throughout the merozoite life cycle stage of apicomplexan parasites; contains proteins destined to be secreted into the parasitophorous vacuole following parasite invasion of a host cell.


zymogen granule

A membrane-bounded, cytoplasmic secretory granule found in enzyme-secreting cells and visible by light microscopy. Contain zymogen, an inactive enzyme precursor, often of a digestive enzyme.


clathrin-coated vesicle

A vesicle with a coat formed of clathrin connected to the membrane via one of the clathrin adaptor complexes.


chloroplast vesicle

A intracellular vesicle that is part of a chloroplast.


virion transport vesicle

A vesicle used to transport the partial or complete virion between cellular compartments.


bacteroid-containing symbiosome

A symbiosome containing any of various structurally modified bacteria, such as those occurring on the root nodules of leguminous plants.


epidermal lamellar body

A specialized secretory organelle found in keratinocytes and involved in the formation of an impermeable, lipid-containing membrane that serves as a water barrier and is required for correct skin barrier function.


food vacuole

Vacuole within a parasite used for digestion of the host cell cytoplasm. An example of this component is found in the Apicomplexa.


synaptic vesicle, readily releasable pool

A synaptic vesicle belonging to the pool of vesicles that are the first to be released as a result of chemical or electrical stimulation e.g. by an action potential, have the highest presynaptic membrane fusion probability and correspond to about 1% of the total number of synaptic vesicles at a resting terminal bouton.


insulin-responsive compartment

A small membrane-bounded vesicle that releases its contents by exocytosis in response to insulin stimulation; the contents are enriched in GLUT4, IRAP and VAMP2.


A cytoplasmic vesicle composed of both tubulovesicular and clear core vesicles that transport synaptic vesicle-associated proteins. Proteins carried by synaptic vesicle protein transport vesicles (STVs) include synaptophysin, synapsin Ia, synaptotagmin and synaptobrevin/vesicle-associated membrane protein 2 (VAMP2). STVs are packaged via the trans-Golgi network before being transported through the axon.


chitosome

An intracellular membrane-bounded particle found in fungi and containing chitin synthase; it synthesizes chitin microfibrils. Chitin synthase activity exists in chitosomes and they are proposed to act as a reservoir for regulated transport of chitin synthase enzymes to the division septum.


phagocytic vesicle

A membrane-bounded intracellular vesicle that arises from the ingestion of particulate material by phagocytosis.


endocytic vesicle

A membrane-bounded intracellular vesicle formed by invagination of the plasma membrane around an extracellular substance. Endocytic vesicles fuse with early endosomes to deliver the cargo for further sorting.


COPI-coated inter-Golgi transport vesicle

A vesicle that mediates transport of cargo within the Golgi complex (for example, between cisternae of the Golgi stack).


early endosome

A membrane-bounded organelle that receives incoming material from primary endocytic vesicles that have been generated by clathrin-dependent and clathrin-independent endocytosis; vesicles fuse with the early endosome to deliver cargo for sorting into recycling or degradation pathways.


melanosome

A tissue-specific, membrane-bounded cytoplasmic organelle within which melanin pigments are synthesized and stored. Melanosomes are synthesized in melanocyte cells.


neuronal dense core vesicle

A dense core vesicle (granule) that is part of a neuron. These vesicles typically contain neuropeptides. They can be found in all parts of neurons, including the soma, dendrites, axonal swellings (varicosities) and synaptic terminals.


clathrin-sculpted gamma-aminobutyric acid transport vesicle

A clathrin-sculpted lipid bilayer membrane-enclosed vesicle after clathrin release and containing gamma-aminobutyric acid transport vesicle.


leucosome

A tissue-specific, membrane-bounded cytoplasmic organelle within which uric acid and/or purines crystalize in reflective stacks. Leucosomes are synthesized in leucophore cells and have a whitish cast.


pigment granule

A small, subcellular membrane-bounded vesicle containing pigment and/or pigment precursor molecules. Pigment granule biogenesis is poorly understood, as pigment granules are derived from multiple sources including the endoplasmic reticulum, coated vesicles, lysosomes, and endosomes.


clathrin-coated endocytic vesicle

A clathrin-coated, membrane-bounded intracellular vesicle formed by invagination of the plasma membrane around an extracellular substance.


carotenoid vesicle

A tissue-specific cytoplasmic vesicle surrounded by a membrane half-leaflet within which carotenoid pigments are stored. Carotenoid vesicles are synthesized in xanthophores and erythrophore cells and are yellow, orange or red in appearance.


early phagosome

A membrane-bounded intracellular vesicle as initially formed upon the ingestion of particulate material by phagocytosis.


pexophagosome

A membrane-bounded intracellular vesicle involved in the degradation of peroxisome by macropexophagy.


mucocyst

A small subcellular vesicle, surrounded by a membrane, in the pellicle of ciliate protozoans that discharges a mucus-like secretion.


dense core granule

Electron-dense organelle with a granular internal matrix; contains proteins destined to be secreted.


cortical granule

A secretory vesicle that is stored under the cell membrane of an egg. These vesicles fuse with the egg plasma membrane as part of egg activation and are part of the block to polyspermy.


sorting endosome

A multivesicular body surrounded by and connected with multiple tubular compartments with associated vesicles.


gut granule

A lysosome-related organelle contained within the intestinal cells of the nematode C. elegans. Gut granules are acidified, birefringent, autofluorescent, and contain the vacuolar H+-ATPase. They also serve as sites of cellular zinc storage.


pinosome

A membrane-bounded, uncoated intracellular vesicle formed by the process of pinocytosis.


multivesicular body, internal vesicle

A membrane-bounded vesicle wholly contained within a multivesicular body.


clathrin-sculpted vesicle

A clathrin-sculpted lipid bilayer membrane-enclosed vesicle after clathrin release.


COPI-coated vesicle

A vesicle with a coat formed of the COPI coat complex proteins. COPI-coated vesicles are found associated with Golgi membranes at steady state, are involved in Golgi to endoplasmic reticulum (retrograde) vesicle transport, and possibly also in intra-Golgi transport.


synaptic vesicle, recycling pool

A synaptic vesicle belonging to the pool that repopulate vacancies within the readily releasable pool (RRP) of synaptic vesicles, and require more significant stimuli than the RRP in order to release neurotransmitter; about 10-15% of the total number of synaptic vesicles at a resting terminal bouton are in this state.


alveolar lamellar body

A specialized secretory organelle found in type II pneumocytes and involved in the synthesis, secretion, and reutilization of pulmonary surfactant.


neurosecretory vesicle

A large cytoplasmic membrane-bounded vesicle with an electron dense granular core, up to 150-200 nm in diameter, found in neurosecretory cells in the hypothalamus.


clathrin-coated phagocytic vesicle

A clathrin-coated, membrane-bounded intracellular vesicle that arises from the ingestion of particulate material by phagocytosis.


postsynaptic recycling endosome

A recycling endosome of the postsynapse. In postsynaptic terminals with dendritic spines, it is typically located at the base of a dendritic spine. It is involved in recycling of neurotransmitter receptors to the postsynaptic membrane. In some cases at least, this recycling is activated by postsynaptic signalling and so can play a role in long term potentiation.


coated vesicle

Small membrane-bounded organelle formed by pinching off of a coated region of membrane. Some coats are made of clathrin, whereas others are made from other proteins.


ciliary vesicle

A Golgi-derived vesicle to which the ciliary basal body docks via its transitional fibers. Its membrane is compositionally distinct from Golgi membranes, and will become the ciliary membrane once the ciliary vesicle is fused to the plasma membrane. The ciliary vesicle is thought to be formed by multiple smaller vesicles that attach to the transitional fibers and then fuse to form a larger vesicle.


platelet dense granule

Electron-dense granule occurring in blood platelets that stores and secretes adenosine nucleotides and serotonin. They contain a highly condensed core consisting of serotonin, histamine, calcium, magnesium, ATP, ADP, pyrophosphate and membrane lysosomal proteins.


micropinosome

A membrane-bounded, uncoated intracellular vesicle formed by the process of micropinocytosis.


transport vesicle

Any of the vesicles of the constitutive secretory pathway, which carry cargo from the endoplasmic reticulum to the Golgi, between Golgi cisternae, from the Golgi to the ER (retrograde transport) or to destinations within or outside the cell.


synaptic vesicle

A secretory organelle, typically 50 nm in diameter, of presynaptic nerve terminals; accumulates in high concentrations of neurotransmitters and secretes these into the synaptic cleft by fusion with the 'active zone' of the presynaptic plasma membrane.


endosome to plasma membrane transport vesicle

A transport vesicle that mediates transport from the endosome to the plasma membrane, and fuses with the plasma membrane to deliver lipids and membrane proteins to the plasma membrane and to release various cargo molecules, such as proteins or hormones, by exocytosis.


Golgi to plasma membrane transport vesicle

A transport vesicle that mediates transport from the Golgi to the plasma membrane, and fuses with the plasma membrane to release various cargo molecules, such as proteins or hormones, by exocytosis.


dendritic lamellar body

A specialized secretory organelle found in neurons and associated with the formation of dendrodendritic gap junctions.


recycling endosome

An organelle consisting of a network of tubules that functions in targeting molecules, such as receptors transporters and lipids, to the plasma membrane.


azurophil granule

Primary lysosomal granule found in neutrophil granulocytes. Contains a wide range of hydrolytic enzymes and is released into the extracellular fluid.


symbiosome

A double-enveloped cell compartment, composed of an endosymbiont with its plasmalemma (as inner envelope) and a non-endosymbiotic outer envelope (the perisymbiontic membrane).


lamellar body

A membrane-bounded organelle, specialized for the storage and secretion of various substances (surfactant phospholipids, glycoproteins and acid phosphates) which are arranged in the form of tightly packed, concentric, membrane sheets or lamellae. Has some similar properties to, but is distinct from, a lysosome.


contractile vacuole

A specialized vacuole of eukaryotic cells, especially Protozoa, that fills with water from the cytoplasm and then discharges this externally by the opening of contractile vacuole pores. One of its functions is osmoregulatory.


trans-Golgi network transport vesicle

A vesicle that mediates transport between the trans-Golgi network and other parts of the cell.


aleurone grain

A membrane-bounded storage granule found in cells of the aleurone layer in plants; contains either a protein matrix, protein-carbohydrate bodies and/or globoids. Aleurone grains are formed by the vacuole, rough endoplasmic reticulum and dictyosomes.


mucin granule

A secretory granule that contains mucin.


clathrin-sculpted acetylcholine transport vesicle

A clathrin-sculpted lipid bilayer membrane-enclosed vesicle after clathrin release and containing acetylcholine.


Cvt vesicle

A cytosolic vesicle that is enclosed by a double membrane and is implicated in the cytoplasm to vacuole targeting pathway. These vesicles are found in the yeast S. cerevisiae, and contain vacuolar hydrolases, aminopeptidase I (Ape1p) and alpha-mannosidase (Ams1p).


acrosomal vesicle

A structure in the head of a spermatozoon that contains acid hydrolases, and is concerned with the breakdown of the outer membrane of the ovum during fertilization. It lies just beneath the plasma membrane and is derived from the lysosome.


COPII-coated ER to Golgi transport vesicle

A vesicle with a coat formed of the COPII coat complex proteins. The COPII coat complex is formed by the Sec23p/Sec24p and the Sec13p/Sec31p heterodimers. COPII-associated vesicles transport proteins from the rough endoplasmic reticulum to the Golgi apparatus (anterograde transport).


secretory vesicle

A cytoplasmic, membrane bound vesicle that is capable of fusing to the plasma membrane to release its contents into the extracellular space.


apical recycling endosome

Tubulo-vesicular structure located in the apical cytoplasm that participates in apical cargo recycling in polarized epithelial cells.


organellar chromatophore

A bacteroid-containing symbiosome in which the bacterial component is a genetically highly reduced cyanobacterium that is photosynthetically active and incapable of an independent existence outside its host. The chromatophore functions as a photosynthetic organelle, and has been found and characterized in the amoeba Paulinella chromatophora.


phagolysosome

A membrane-bounded intracellular vesicle formed by maturation of an early phagosome following the ingestion of particulate material by phagocytosis; during maturation, phagosomes acquire markers of late endosomes and lysosomes.


cyanosome

A tissue-specific, membrane-bounded cytoplasmic organelle within which an unknown blue pigment is localized. Cyanosomes are synthesized in cyanophores and are blue in appearance.


Golgi-associated vesicle

Any vesicle associated with the Golgi complex and involved in mediating transport within the Golgi or between the Golgi and other parts of the cell.


amorphous vesicle

A cytoplasmic membrane-bounded vesicle first described in dendrites, categorized by smooth membranes, electron-lucent interiors and irregular shapes. Sometimes occurs in clumps. Amorphous vesicles have been found to contain material taken up from the extracellular space, therefore suggesting that they may be part of the endosomal pathway.


specific granule

Granule with a membranous, tubular internal structure, found primarily in mature neutrophil cells. Most are released into the extracellular fluid. Specific granules contain lactoferrin, lysozyme, vitamin B12 binding protein and elastase.


osmiophilic body

A membrane-bounded vesicle found predominantly in Plasmodium female gametocytes, that becomes progressively more abundant as the gametocyte reaches full maturity. These vesicles lie beneath the subpellicular membrane of the gametocyte, and the release of their contents into the parasitophorous vacuole has been postulated to aid in the escape of gametocytes from the erythrocyte after ingestion by the mosquito.


clathrin-sculpted monoamine transport vesicle

A clathrin-sculpted lipid bilayer membrane-enclosed vesicle after clathrin release and containing monoamines.


pterinosome

A tissue-specific, membrane-bounded cytoplasmic organelle within which pteridine pigments are synthesized and stored. Pterinosomes are synthesized in xanthophores and erythrophore cells and are yellow, orange or red in appearance.


chromaffin granule

Specialized secretory vesicle found in the cells of adrenal glands and various other organs, which is concerned with the synthesis, storage, metabolism, and secretion of epinephrine and norepinephrine.


sperm cytoplasmic droplet

A small amount of cytoplasm surrounded by a cell membrane that is generally retained in spermatozoa after spermiogenesis, when the majority of the cytoplasm is phagocytosed by Sertoli cells to produce what are called residual bodies. Initially, the droplet is located at the neck just behind the head of an elongated spermatid. During epididymal transit, the cytoplasmic droplet migrates caudally to the annulus at the end of the midpiece; the exact position and time varies by species. The cytoplasmic droplet consists of lipids, lipoproteins, RNAs, a variety of hydrolytic enzymes, receptors, ion channels, and Golgi-derived vesicles. The droplet may be involved in regulatory volume loss (RVD) at ejaculation, and in most species, though not in humans, the cytoplasmic droplet is lost at ejaculation. Note that the cytoplasmic droplet is distinct from 'excessive residual cytoplasm' that sometimes remains in epididymal spermatozoa, particularly when spermiogenesis has been disrupted.


presynaptic endosome

An endosome present in the presynapse that fuses with endocytic vesicles arising in the presynaptic endocytic zone. This organelle is believed to be involved in regeneration of synaptic vesicles.


fusiform vesicle

A cytoplasmic vesicle which contains two urothelial plaques and can deliver these plaques to the apical plasma membrane of urothelial superficial (umbrella) cells. It can also be formed by endocytosis of apical plasma membrane during contractions of the urinary bladder.


macropinosome

A membrane-bounded, uncoated intracellular vesicle formed by the process of macropinocytosis.


granular vesicle

A cytoplasmic membrane-bounded vesicle of varying size, but usually larger than 45 nm, with an electron dense granular core, found in noradrenergic and peptidergic cells.


ficolin-1-rich granule

Highly exocytosable gelatinase-poor granules found in neutrophils and rich in ficolin-1. Ficolin-1 is released from neutrophil granules by stimulation with fMLP or PMA, and the majority becomes associated with the surface membrane of the cells and can be detected by flow cytometry.


esterosome

A vesicle filled with crystalline protein that shows sequence similarities with various esterases.


endosome

A vacuole to which materials ingested by endocytosis are delivered.


basolateral recycling endosome

Tubulo-vesicular structure located in the basolateral cytoplasm that participates in basolateral cargo recycling in polarized epithelial cells.


exocytic vesicle

A transport vesicle that mediates transport from an intracellular compartment to the plasma membrane, and fuses with the plasma membrane to release various cargo molecules, such as proteins or hormones, by exocytosis.


endolysosome

An transient hybrid organelle formed by fusion of a late endosome with a lysosome, and in which active degradation takes place.


pericanalicular vesicle

A membrane-bounded vesicle found near the apical, or pericanalicular, membrane of a hepatocyte; contains proteins involved in bile salt transport and other fluid and solute transport processes.


postsynaptic early endosome

An early endosome of the postsynapse. It acts as the major sorting station on the endocytic pathway, targeting neurotransmitter receptors for degregation or recycling.


tertiary granule

A secretory granule that contains cathepsin and gelatinase and is readily exocytosed upon cell activation; found primarily in mature neutrophil cells.


cytoplasmic vesicle

A vesicle found in the cytoplasm of a cell.


postsynaptic endosome

An endosomal compartment that is part of the post-synapse. Only early and recycling endosomes are typically present in the postsynapse.


CGRP receptor complex

A transmembrane, G protein-coupled signalling receptor complex recognized by calcitonin gene-related peptides (CGRP).


calcitonin family receptor complex

A protein complex which is capable of calcitonin family receptor activity. Calcitonin family receptors may form dimers, trimers or tetramers; adrenomedullin and amylin receptors have only been observed as dimers so far.


adrenomedullin receptor complex

A transmembrane, G protein-coupled signalling receptor complex which is capable of adrenomedullin receptor activity.


amylin receptor complex 3

A G protein-coupled receptor complex that serves as a receptor for amylin polypeptide (AMY) and consists of a calcitonin receptor (CTR/CALCR) and a receptor activity-modifying protein (RAMP) 3. Amylin receptor complex 3 (AMY3) also serves as a receptor for the amyloid-beta complex. Ligand binding to AMY3 results in increased cytosolic calcium ion levels and in activation on multiple intracellular signalling pathways.


amylin receptor complex

A protein complex which is capable of amylin receptor activity.


amylin receptor complex 1

A G protein-coupled receptor complex that serves as a receptor for amylin polypeptide (AMY) and consists of a calcitonin receptor (CTR/CALCR) and a receptor activity-modifying protein (RAMP) 1. Amylin receptor complex 1 (AMY1) also serves as a receptor for the calcitonin related peptide (CGRP) and adrenomedullin (AM/ADM).


amylin receptor complex 2

A G protein-coupled receptor complex that serves as a receptor for amylin polypeptide (AMY) and consists of a calcitonin receptor (CTR/CALCR) and a receptor activity-modifying protein (RAMP) 2. Amylin receptor complex 2 (AMY2) also serves as a receptor for adrenomedullin (AM/ADM).


MutS complex

A homodimeric mismatch repair complex involved in binding to and correcting insertion/deletion mutations.


mismatch repair complex

Any complex formed of proteins that act in mismatch repair.


MutSalpha complex

A heterodimer involved in the recognition and repair of base-base and small insertion/deletion mismatches. In human the complex consists of two subunits, MSH2 and MSH6.


MutSgamma complex

A heterodimer involved in the stabilization of DNA recombination intermediates, the promotion of crossover recombination, and the proper assembly of the synaptonemal complex in meiotic prophase nuclei. In yeast the complex consists of two subunits, Msh4 and Msh5.


MutLbeta complex

A heterodimer involved in the recognition of base-base and small insertion/deletion mismatches. In human the complex consists of two subunits, MLH1 and PMS1.


MutSbeta complex

A heterodimer involved in binding to and correcting insertion/deletion mutations. In human the complex consists of two subunits, MSH2 and MSH3.


MutLalpha complex

A heterodimer involved in the recognition of base-base and small insertion/deletion mismatches. In human the complex consists of two subunits, MLH1 and PMS2.


MutLgamma complex

A heterodimer involved in the recognition of base-base and small insertion/deletion mismatches. In S. cerevisiae the complex consists of two subunits, Mlh1 and Mlh3.


MAML2-RBP-Jkappa-ICN4 complex

A protein complex that consists of the intracellular domain of Notch4 (ICN4), the DNA-binding transcription factor RBP-Jkappa, and the transcriptional coactivator Mastermind-like-2 (MAML2); the complex is involved in transcriptional activation in response to Notch-mediated signaling.


A protein complex that contains the cell adhesion molecules protocadherin-alpha-v4 and protocadherin-gamma-b2, and is involved in the regulation of protein localization to the plasma membrane.


Hrd1p ubiquitin ligase ERAD-L complex

A multiprotein complex that recognizes and ubiquitinates proteins with misfolded luminal domains during ER-associated protein degradation (ERAD). In S. cerevisiae, this complex contains the ubiquitin ligase Hrd1p.


brahma complex

A SWI/SNF-type complex that contains 8 to 14 proteins, including both conserved (core) and nonconserved components; contains the ATPase product of the Drosophila brm (brahma) or mammalian SMARCA2/BAF190B/BRM gene, or an ortholog thereof.


TIM23 mitochondrial import inner membrane translocase complex

The protein transport machinery of the mitochondrial inner membrane that typically transports proteins that possess a matrix-targeting N-terminal presequence. The TIM23 complex contains three essential Tim proteins: Tim17 and Tim23 are thought to build a preprotein translocation channel while Tim44 interacts transiently with the matrix heat-shock protein Hsp70 to form an ATP-driven import motor.


tubovesicular membrane network

A complex, symbiont-induced host-derived organelle that is comprised of multiple protein and lipid domains.


Grb2-EGFR complex

A protein complex that contains the epidermal growth factor receptor (EGFR) and Grb2, and is involved in linking EGFR activation to the p21-Ras pathway.


mitochondrial endopeptidase Clp complex

A Clp endopeptidase complex located in the mitochondrion.


SWI/SNF complex

A SWI/SNF-type complex that contains 8 to 14 proteins, including both conserved (core) and nonconserved components; contains the ATPase product of the yeast SNF2 or mammalian SMARCA4/BAF190A/BRG1 gene, or an ortholog thereof.


signal recognition particle, plasma membrane targeting

A complex consisting of a protein and RNA component which binds the signal sequence of some proteins and facilitates their export to or across the plasma membrane.


centriolar satellite

A small (70-100 nm) cytoplasmic granule that contains a number of centrosomal proteins; centriolar satellites traffic toward microtubule minus ends and are enriched near the centrosome.


transcription factor TFIIIB-alpha complex

A transcription factor TFIIIB-beta complex that contains the TATA-binding protein (TBP), B'' and a specialized homolog of the conserved subunit BRF referred to as BRFU or TFIIIB50, which found in human but not conserved in yeast; the complex is involved in the regulation of transcription from type 3 (upstream) RNA polymerase III promoters.


sperm connecting piece

The segment of the sperm flagellum that attaches to the implantation fossa of the nucleus in the sperm head; from the remnant of the centriole at this point, the axoneme extends throughout the length of the flagellum.


Golgi trans cisterna membrane

The lipid bilayer surrounding any of the thin, flattened compartments that form the trans portion of the Golgi complex.


Golgi cisterna membrane

The lipid bilayer surrounding any of the thin, flattened compartments that form the central portion of the Golgi complex.


Golgi medial cisterna membrane

The lipid bilayer surrounding any of the thin, flattened compartments that form the medial portion of the Golgi complex.


Golgi cis cisterna membrane

The lipid bilayer surrounding any of the thin, flattened compartments that form the cis portion of the Golgi complex.


myosin V complex

A myosin complex containing a dimer of class V myosin heavy chains and associated light chains; involved in intracellular transport. Myosin V is a dimeric molecule consisting of conserved motor domains followed by 6 IQ motifs which bind specific light chains and calmodulin. The tail domain is important for cellular localization and cargo binding and can be divided into an alpha-helical coiled coil region and a C-terminal globular region.


excinuclease repair complex

Any of the protein complexes formed by the UvrABC excinuclease system, which carries out nucleotide excision repair. Three different complexes are formed by the 3 proteins as they proceed through the excision repair process. First a complex consisting of two A subunits and two B subunits bind DNA and unwind it around the damaged site. Then, the A subunits disassociate leaving behind a stable complex between B subunits and DNA. Now, subunit C binds to this B+DNA complex and causes subunit B to nick the DNA on one side of the complex while subunit C nicks the DNA on the other side of the complex. DNA polymerase I and DNA ligase can then repair the resulting gap.


TRAF2-GSTP1 complex

A protein complex comprising tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) and glutathione S-transferase pi 1 (GSTP1). This complex is thought to disrupt the TNF signaling cascade, thus down-regulating inflammatory responses.


axon cytoplasm

Any cytoplasm that is part of a axon.


plus-end kinesin complex

Any complex that includes a dimer of molecules from the kinesin superfamily and any associated proteins, and moves towards the plus end of a microtubule.


kinesin complex

Any complex that includes a dimer of molecules from the kinesin superfamily, a group of related proteins that contain an extended region of predicted alpha-helical coiled coil in the main chain that likely produces dimerization. The native complexes of several kinesin family members have also been shown to contain additional peptides, often designated light chains as all of the noncatalytic subunits that are currently known are smaller than the chain that contains the motor unit. Kinesin complexes generally possess a force-generating enzymatic activity, or motor, which converts the free energy of the gamma phosphate bond of ATP into mechanical work.


kinesin I complex

A complex of two kinesin heavy chains and two kinesin light chains.


kinesin II complex

A complex consisting of two distinct motor subunits that form a heterodimer complexed with a third non-motor accessory subunit, the kinesin associated protein or KAP; the KIF3 heterodimer interacts via its C-terminal portion with KAP, which is thought to regulate the binding of the motor to cargo membranes.


minus-end kinesin complex

Any complex that includes a dimer of molecules from the kinesin superfamily and any associated proteins, and moves towards the minus end of a microtubule.


axonemal central bridge

Part of the 9+2 axoneme, that occurs in most motile cilia, consisting of the two bridges which connect the central pair of single microtubules.


triglyceride-rich plasma lipoprotein particle

A plasma lipoprotein particle that has a hydrophobic core enriched in triglycerides surrounded by an amphipathic monolayer of phospholipids, cholesterol and apolipoproteins. Triglyceride-rich lipoprotein particles transport lipids, which are non-covalently associated with the particles, in the blood.


very-low-density lipoprotein particle

A triglyceride-rich lipoprotein particle that is typically composed of APOB100, APOE and APOCs and has a density of about 1.006 g/ml and a diameter of between 20-80 nm. It is found in blood and transports endogenous products (newly synthesized cholesterol and triglycerides) from the liver.


A triglyceride-rich lipoprotein particle that typically contains APOB100, APOE and APOCs and has a density of 1.006-1.019 g/ml and a diameter of between 25-30 nm. IDL particles are found in blood and are formed by the delipidation of very-low-density lipoprotein particles (VLDL). IDL particles are removed from blood by the liver, following binding to the APOE receptor, or are converted to low-density lipoprotein (LDL).


LinE complex

A protein complex that associates with chromatin to form linear elements in fission yeast. In S. pombe, the LinE complex contains four main structural components (Rec10, Rec25, Rec27, and Mug20) and other associated proteins.


myosin II filament

A bipolar filament composed of myosin II molecules.


macropinocytic cup membrane

The portion of the plasma membrane surrounding a macropinocytic cup.


sensory dendrite

A dendrite that is found on a sensory neuron, and directly transduces a sensory signal from the sensory neuron to another neuron.


Elg1 RFC-like complex

A pentameric replication factor C (RLC) complex, which unloads the DNA polymerase processivity factor proliferating cell nuclear antigen (PCNA) from chromatin and has roles in telomere length regulation and other aspects of genome stability. In Saccharomyces the subunits are known as Elg1p, Rfc2p, Rfc3p, Rfc4p, and Rfc5p.


A homodimeric, bifunctional enzyme complex which catalyzes the synthesis and degradation of fructose 2,6-bisphosphate, and is required for both glycolysis and gluconeogenesis.


ER-to-endosome phospholipid transfer complex

Lipid transfer complex that is responsible for the non-vesicular transport of phospholipids, such as phosphatidylserine, from the endoplasmic reticulum to the endosome. It resides in the endosomal (acceptor) membrane and binds to specific lipids on the donor membrane at the ER-endosome contact site.


cytoplasmic side of Golgi membrane

The side (leaflet) of the Golgi membrane that faces the cytoplasm.


external side of mycolate outer membrane

The side (leaflet) of the mycolate outer membrane that faces the environment and any proteins embedded in it or loosely bound to its surface.


cytoplasmic side of membrane

The side of a membrane that faces the cytoplasm.


external side of plasma membrane

The leaflet of the plasma membrane that faces away from the cytoplasm and any proteins embedded or anchored in it or attached to its surface.


lumenal side of early endosome membrane

The side (leaflet) of the early endosome membrane that faces the lumen.


lumenal side of transport vesicle membrane

The side (leaflet) of the transport vesicle membrane that faces the lumen.


periplasmic side of plasma membrane

The side (leaflet) of a plasma membrane that faces the periplasm, and all proteins embedded in it or attached to its surface.


cytoplasmic side of mitochondrial outer membrane

The external (cytoplasmic) face of the mitochondrial outer membrane.


lumenal side of endosome membrane

The side (leaflet) of the endosome membrane that faces the lumen.


cytoplasmic side of plasma membrane

The leaflet the plasma membrane that faces the cytoplasm and any proteins embedded or anchored in it or attached to its surface.


matrix side of mitochondrial inner membrane

The side (leaflet) of the mitochondrial inner membrane that faces the matrix.


cytoplasmic side of endoplasmic reticulum membrane

The side (leaflet) of the plasma membrane that faces the cytoplasm.


lumenal side of late endosome membrane

The side (leaflet) of the late endosome membrane that faces the lumen.


cytoplasmic side of transport vesicle membrane

The side (leaflet) of the transport vesicle membrane that faces the cytoplasm.


lumenal side of membrane

Any side (leaflet) of a membrane that faces the lumen of an organelle.


stromal side of plastid inner membrane

The side (leaflet) of the plastid inner membrane that faces the stroma, and any proteins embedded in it or loosely bound to its surface.


periplasmic side of cell outer membrane

The side (leaflet) of the outer membrane that faces the periplasm of the cell.


cytoplasmic side of trans-Golgi network transport vesicle membrane

The side (leaflet) of the trans-Golgi network transport vesicle membrane that faces the cytoplasm.


internal side of mycolate outer membrane

The side of the mycolate outer membrane that faces the cell wall peptidoglycan. It is rich in long-chain mycolic acids (hydroxylated branched-chain fatty acids) that are covalently linked to the cell wall peptidoglycan via an arabinogalactan network.


cytoplasmic side of plasma membrane, cell tip

The leaflet the plasma membrane at the cell tip that faces the cytoplasm and any proteins embedded or anchored in it or attached to its surface.


lumenal side of plastid thylakoid membrane

The side (leaflet) of the plastid thylakoid membrane that faces the lumen, and any proteins embedded in it or loosely bound to its surface.


external side of apical plasma membrane

The leaflet the apical region of the plasma membrane that faces away from the cytoplasm and any proteins embedded or anchored in it or attached to its surface.


cytoplasmic side of dendritic spine plasma membrane

The leaflet of the plasma membrane that faces the cytoplasm and any proteins embedded or anchored in it or attached to its surface surrounding a dendritic spine.


lumenal side of trans-Golgi network transport vesicle membrane

The side (leaflet) of the trans-Golgi network transport vesicle membrane that faces the lumen.


stromal side of plastid thylakoid membrane

The side (leaflet) of the plastid thylakoid membrane that faces the stroma, and any proteins embedded in it or loosely bound to its surface.


lumenal side of Golgi membrane

The side of the Golgi membrane that faces the lumen.


cytoplasmic side of smooth endoplasmic reticulum membrane

The side (leaflet) of the smooth endoplasmic reticulum membrane that faces the cytoplasm.


cytoplasmic side of rough endoplasmic reticulum membrane

The side (leaflet) of the rough endoplasmic reticulum membrane that faces the cytoplasm.


cytoplasmic side of endosome membrane

The side (leaflet) of the endosome membrane that faces the cytoplasm.


external side of cell outer membrane

The side of the outer membrane that is opposite to the side that faces the periplasm of the cell.


cytoplasmic side of early endosome membrane

The side (leaflet) of the early endosome membrane that faces the cytoplasm.


cytoplasmic side of lysosomal membrane

The side (leaflet) of the lysosomal membrane that faces the cytoplasm.


6-phosphofructokinase complex

A protein complex that possesses 6-phosphofructokinase activity; homodimeric, homooctameric, and allosteric homotetrameric forms are known.


mitotic spindle pole body

The microtubule organizing center that forms as part of the mitotic cell cycle; functionally homologous to the animal cell centrosome.


old mitotic spindle pole body

The spindle pole body that exists in a cell prior to spindle pole body duplication. An old spindle pole body segregates to the daughter cell upon mitosis, and lacks active proteins involved in signaling exit from mitosis.


new mitotic spindle pole body

The spindle pole body that is formed by spindle pole body duplication, and to which proteins involved in mitotic exit signaling (for example, the septation initiation network in fission yeast) localize.


G-protein alpha(q)-synembrin complex

A protein complex formed by the association of the guanine nucleotide exchange factor synembrin with the alpha(q) subunit of a heterotrimeric G protein.


plastid acetyl-CoA carboxylase complex

An acetyl-CoA carboxylase complex located in the stroma of a plastid.


acetyl-CoA carboxylase complex

A protein complex that catalyzes the first step in long-chain fatty acid biosynthesis. For example, in E. coli the complex is heterohexameric and composed of biotin carbonyl carrier protein, biotin carboxylase and the acetate CoA-transferase complex.


IgG B cell receptor complex

An IgG immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of an IgG isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins.


tubulin complex

A heterodimer of tubulins alpha and beta that constitutes the protomer for microtubule assembly.


mitochondrial inner membrane assembly complex

A protein complex that promotes the biogenesis of mitochondrial F1Fo-ATP synthase by facilitating assembly of the peripheral stalk. Loss of INAC function causes dissociation of the F1-domain from the membrane-integral Fo-portion.


Gram-negative-bacterium-type cell wall

The peptidoglycan layer of the Gram-negative cell envelope. In Gram-negative cells the peptidoglycan is relatively thin (1-2nm) and is linked to the outer membrane by lipoproteins. In Gram-negative cells the peptidoglycan is too thin to retain the primary stain in the Gram staining procedure and therefore cells appear red after Gram stain.


A homohexameric complex that recognizes and unfolds core proteasome substrate proteins, and translocates them to the core complex in an ATP dependent manner.


photoreceptor cell terminal bouton

A specialized region of the axon terminus portion of a photoreceptor cell axon. A photoreceptor cell is a neuron specialized to detect and transduce light.


recycling endosome lumen

The volume enclosed by the membranes of a recycling endosome.


Lewy body-like hyaline inclusion

Cytoplasmic inclusion found in neurons. It consists of filaments and granular materials, exhibits a dense core with a rough peripheral halo and lacks a limiting membrane. The filaments of these inclusions are composed of approximately 15-25 nm granule-coated fibrils in association with normal 10-nm neurofilaments.


P-TEFb-cap methyltransferase complex

A protein complex that is formed by the association of positive transcription elongation factor complex b (P-TEFb) with the mRNA capping methyltransferase.


lysosomal multienzyme complex

A protein complex found in the lysosome that contains beta-galactosidase, cathepsin A, alpha-neuraminidase and N-acetylgalactosamine-6-sulfate sulfatase, and is involved in glycosaminoglycan catabolism.


perichromatin fibrils

Structures of variable diameter visible in the nucleoplasm by electron microscopy, mainly observed near the border of condensed chromatin. The fibrils are enriched in RNA, and are believed to be sites of pre-mRNA splicing and polyadenylylation representing the in situ form of nascent transcripts.


caveola bulb

The region of a caveola that extends into the cytoplasm, excluding the neck (rim). This region is associated with intracellular caveola proteins.


collagen anchoring fibril

A specialised collagen fibril that functions as an anchor, binding to other collagen structures.


collagen type VII anchoring fibril

An antiparallel dimer of two collagen VII trimers, one end of which is embedded in the lamina densa while the other end attaches to banded collagen fibrils in the dermis.


cytosolic DNA-directed RNA polymerase complex

The eubacterial DNA-directed RNA polymerase is a multisubunit complex with a core composed of the essential subunits beta-prime, beta, and two copies of alpha and a fifth nonessential subunit called omega. An additional subunit, a sigma factor, is required for promoter recognition and specificity.


catenin-TCF7L2 complex

A protein complex that contains a catenin and TCF7L2 (TCF4), binds to the TCF DNA motif within a promoter element, and is involved in the regulation of WNT target gene transcription.


beta-catenin-TCF7L2 complex

A protein complex that contains beta-catenin and TCF7L2 (TCF4), binds to the TCF DNA motif within a promoter element, and is involved in the regulation of WNT target gene transcription.


gamma-catenin-TCF7L2 complex

A protein complex that contains gamma-catenin and TCF7L2 (TCF4), binds to the TCF DNA motif within a promoter element, and is involved in the regulation of WNT target gene transcription.


pollen aperture

An area where exine is reduced or absent, in the pollen wall.


eukaryotic translation elongation factor 1 complex

A multisubunit nucleotide exchange complex that binds GTP and aminoacyl-tRNAs, and catalyzes their codon-dependent placement at the A-site of the ribosome. In humans, the complex is composed of four subunits, alpha, beta, delta and gamma.


viral terminase, large subunit

The part of the viral terminase complex that contains the translocase and endonuclease activities and allows the translocation of the phage DNA into the procapsid. The large subunit usually assembles as a heterooligomer with the small subunit.


P5 peroxisome

A subform of peroxisome that corresponds to an intermediate in a peroxisome assembly pathway, which operates by conversion of peroxisomal subforms in the direction P1, P2 -> P3 -> P4 -> P5 -> P6. P5 peroxisomes are distinguished from the other subforms on the bases of buoyant density and protein content.


collagen sheet

A protein complex that consists of collagen triple helices associated to form a sheet-like network.


mitochondrial respiratory chain complex I

A protein complex located in the mitochondrial inner membrane that forms part of the mitochondrial respiratory chain. It contains about 25 different polypeptide subunits, including NADH dehydrogenase (ubiquinone), flavin mononucleotide and several different iron-sulfur clusters containing non-heme iron. The iron undergoes oxidation-reduction between Fe(II) and Fe(III), and catalyzes proton translocation linked to the oxidation of NADH by ubiquinone.


histone pre-mRNA 3'end processing complex

A ribonucleoprotein that binds to specific sites in, and is required for cleavage of, the 3'-end of histone pre-mRNAs. The complex contains the U7 snRNP and additional proteins, including the stem-loop binding protein (SLBP) and the exonuclease 3'hExo/Eri-1.


ISGF3 complex

A transcription factor complex that consists of a Stat1-Stat2 heterodimer and the IRF9 protein.


Ric1-Rgp1 guanyl-nucleotide exchange factor complex

A protein complex that acts as a nucleotide exchange factor for the GTPase Ypt6p, and is required for fusion of endosome-derived vesicles with the Golgi.


A protein complex that comprises one integrin alphav subunit, one integrin beta5 subunit, and vitronectin.


meiotic recombination initiation complex

A protein complex that initiates the formation of double-strand breaks (DSBs) required for meiotic recombination. Consists of a protein that catalyses formation of the double-strand breaks (Spo11 in S. cerevisiae and Rec12 in S. pombe), and a number of accessory proteins.


MCM complex

A hexameric protein complex required for the initiation and regulation of DNA replication.


cytosolic proteasome core complex, beta-subunit complex

The proteasome core subcomplex that constitutes the two inner rings of the cytosolic proteasome core complex.


Set3 complex

A histone deacetylase complex that is involved in transcriptional regulation. In S. cerevisiae, this complex consists of Set3p, Snt1p, Hos4p, Sif2p, Cpr1p, Hos2p, and Hst1p.


adenylyltransferase complex

A protein complex which is capable of adenylyltransferase activity.


dimeric IgA immunoglobulin complex

A protein complex composed of two monomeric IgA immunoglobulin complexes linked through both direct disulfide bonds and through a disulfide binded monomer of J chain acting as a bridge. Each IgA monomer consists of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds. Dimeric IgA is sometimes complexed additionally with secretory component, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph.


diamine N-acetyltransferase complex

A protein complex which is capable of diamine N-acetyltransferase activity.


CURI complex

A protein complex that is involved in the transcription of ribosomal genes. In Saccharomyces this complex consists of Ckb2p, Utp22p, Rrp7p and Ifh1p.


laminin-11 complex

A laminin complex composed of alpha5, beta2 and gamma1 polypeptide chains.


translation release factor complex

A heterodimeric complex involved in the release of a nascent polypeptide chain from a ribosome.


GATA2-TAL1-TCF3-Lmo2 complex

A protein complex that contains the zinc finger transcription factor GATA2, the LIM domain protein Lmo2 (RBTN2), the basic helix-loop-helix protein TAL1 and its binding partner TCF3. The complex is involved transcriptional regulation in hematopoiesis.


flotillin complex

A protein complex that contains flotillin-1 and flotillin-2, and may contain associated proteins. Flotillins associate into membrane microdomains resembling caveolae.


Kelch-containing formin regulatory complex

A protein complex that regulates actin cable formation, polarized cell growth, and cytokinesis in a formin-dependent manner. In S. cerevisiae the complex is composed of Bud14p and two Kelch family proteins, Kel1p and Kel2p.


Derlin-1-VIMP complex

A protein complex containing, in mammals, Derlin-1 and VCP-interacting membrane protein (VIMP). The complex links the p97/VCP-containing ATPase complex with Derlin-1 during translocation of protein substrates from the endoplasmic reticulum to the cytosol for degradation by the cytosolic proteasome.


gamma-delta T cell receptor complex

A T cell receptor complex in which the TCR heterodimer comprises gamma and delta chains, associated with the CD3 complex; recognizes antigen directly, without a requirement for processing and presentation by an MHC protein.


Cul8-RING ubiquitin ligase complex

A ubiquitin ligase complex in which a cullin from the Cul8 subfamily and a RING domain protein form the catalytic core. In S. cerevisiae, Mms1p acts as the adaptor protein and substrate specificity is conferred by any of a number of different proteins.


endobrevin-SNAP-25-syntaxin-2 complex

A SNARE complex that contains endobrevin (VAMP8), SNAP-25, and syntaxin 2 (or orthologs thereof).


CAK-ERCC2 complex

A protein complex formed by the association of the cyclin-dependent protein kinase activating kinase (CAK) holoenzyme complex with ERCC2.


postsynaptic endocytic zone

A stably positioned site of clathrin adjacent and physically attached to the postsynaptic specialization, which is the site of endocytosis of post-synaptic proteins.


ATPase complex

A protein complex which is capable of ATPase activity.


myosin III complex

A myosin complex containing a class III myosin heavy chain and associated light chains; myosin III is monomeric myosin that serves as a link between the cytoskeleton and the signaling complex involved in phototransduction, and differs from all other myosins in having an N-terminal kinase domain.


right ventral flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the right ventral basal body and exits the cell body proximally and dorsal to the ventral disc.


protein-carbohydrate complex

A macromolecular complex containing separate protein and carbohydrate molecules. Separate in this context means not covalently bound to each other.


U1 snRNP

A ribonucleoprotein complex that contains small nuclear RNA U1, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U1 snRNP, most of which remain associated with the U1 snRNA both while the U1 snRNP is free or assembled into a series of spliceosomal complexes.


E.F.G complex

A protein complex that comprises three core spliceosomal proteins, designated E, F, and G. Formation of the E.F.G complex is essential but not sufficient for the formation of a stable U1 snRNP complex.


laminin-2 complex

A laminin complex composed of alpha2, beta1 and gamma1 polypeptide chains.


dimeric ribonuclease P complex

A ribonuclease P complex that contains a single RNA molecule that is necessary and usually sufficient for catalysis, and a single protein molecule. Examples of this complex are found in Bacterial species.


MLL1 complex

A protein complex that can methylate lysine-4 of histone H3. MLL1/MLL is the catalytic methyltransferase subunit, and the complex also contains the core components ASH2L, HCFC1/HCF1 WDR5 and RBBP5.


alphav-beta3 integrin-ADAM23 complex

A protein complex that consists of an alphav-beta3 integrin complex bound to the transmembrane metallopeptidase ADAM23.


glutamate dehydrogenase complex

A homomeric protein complex that possesses glutamate dehydrogenase activity. This complex is evolutionarily conserved except that the number of homoprotomers per complex varies.


carbon phosphorus lyase complex

A protein complex which is capable of carbon phosphorus lyase activity.


high-density lipoprotein particle

A lipoprotein particle with a high density (typically 1.063-1.21 g/ml) and a diameter of 5-10 nm that contains APOAs and may contain APOCs and APOE; found in blood and carries lipids from body tissues to the liver as part of the reverse cholesterol transport process.


A SNARE complex that contains synaptobrevin 2 (VAMP2), SNAP-25, and syntaxin 1a (or orthologs thereof).


rDNA heterochromatin

A region of heterochromatin located at the rDNA repeats in a chromosome.


plasma membrane proton-transporting V-type ATPase, V1 domain

The V1 domain of a proton-transporting V-type ATPase found in the plasma membrane.


alpha-heterochromatin

A small, compact region of heterochromatin located in the middle of the polytene chromosome chromocenter, which undergoes little or no replication during polytenization.


protein farnesyltransferase complex

A protein complex that possesses protein farnesyltransferase activity.


DnaB helicase complex

A homohexameric protein complex that possesses DNA helicase activity; functions during DNA replication and repair.


alpha11-beta1 integrin-collagen type I complex

A protein complex that consists of an alpha11-beta1 integrin complex bound to a type I collagen.


retroviral intasome

A tetramer of retroviral integrase subunits tightly associated with a pair of viral DNA ends. Functions to insert viral DNA into a host cell chromosome.


COMA complex

A kinetochore multiprotein complex that bridges the subunits that are in contact with centromeric DNA and the subunits bound to microtubules during kinetochore assembly. In yeast, consists of Ctf19p, Okp1p, Mcm21p, and Ame1p.


protein phosphatase type 2A complex

A protein complex that has protein serine/threonine phosphatase activity that is polycation-stimulated (PCS), being directly stimulated by protamine, polylysine, or histone H1; it constitutes a subclass of several enzymes activated by different histones and polylysine, and consists of catalytic, scaffolding, and regulatory subunits. The catalytic and scaffolding subunits form the core enzyme, and the holoenzyme also includes the regulatory subunit.


type III protein secretion system complex

A complex of approximately 20 proteins, most of which are located in the cytoplasmic membrane that carries out protein secretion in the bacterial type III secretion system; type III secretion also requires a cytoplasmic, probably membrane-associated ATPase.


DNA polymerase III, clamp loader complex

A heptamer that includes the tau and gamma products of the dnaX gene and the chi/psi subcomplex. Confers structural asymmetry that allows the polymerase to replicate both leading and lagging strands.


nuclear proteasome core complex

The core complex of a proteasome located in the nucleus of a cell.


DnaB-DnaG complex

A protein complex containing homohexameric DnaB helicase, and DnaG (a primase). Facilitates the unwinding of double-stranded DNA and the synthesis of RNA primer sequences during DNA replication and repair in Prokaryotes.


glutamate synthase complex

A complex that possesses glutamate synthase activity.


sulfurtransferase complex

A protein complex capable of catalyzing the transfer of sulfur atoms from one compound (donor) to another (acceptor).


H4 histone acetyltransferase complex

A protein complex which is capable of H4 histone acetyltransferase activity.


GroEL-GroES complex

Bacterial chaperonin complex consisting of a heptameric 10kDa chaperonin subunit GroES and a tetradecameric (2x7) 60kDa chaperonin subunit GroEL. The 60kDa subunit possesses ATPase activity while the holo-enzyme is responsible for the correct folding of proteins.


IRE1-TRAF2-ASK1 complex

A protein complex of the endoplasmic reticulum membrane that consists of IRE1 (Inositol-requiring enzyme-1), TRAF2 (TNF receptor-associated factor 2) and ASK1 (Apoptosis signal-regulating kinase 1, a MAP3K).


AP-3 adaptor complex

A heterotetrameric AP-type membrane coat adaptor complex that consists of beta3, delta, mu3 and sigma3 subunits and is found associated with endosomal membranes. AP-3 does not appear to associate with clathrin in all organisms. In at least humans, the AP-3 complex can be heterogeneric due to the existence of multiple subunit isoforms encoded by different genes (beta3A and beta3B, mu3A and mu3B, and sigma3A and sigma3B).


mitochondrial pyruvate dehydrogenase (lipoamide) phosphatase complex

A mitochondrial complex of a regulatory and catalytic subunit that catalyzes the dephosphorylation and concomitant reactivation of the alpha subunit of the E1 component of the pyruvate dehydrogenase complex. An example of this component is found in Mus musculus.


chloride channel complex

An ion channel complex through which chloride ions pass.


transcription export complex 2

A protein complex that couples SAGA-dependent gene expression to mRNA export at the inner side of the nuclear pore complex (NPC). The TREX-2 complex is tethered to the inner side of the NPC via the nucleoporins Nup1 and Nup60; in S. cerevisiae it contains Sac3p, Thp1p, Sem1, Sus1p and Cdc31p.


cellulose synthase complex

A large, multimeric protein complex, organized in a rosette, which catalyzes the biosynthesis of cellulose for the plant cell wall.


trimethylamine-N-oxide reductase (cytochrome c) complex

A protein complex which is capable of trimethylamine-N-oxide reductase (cytochrome c) activity.


beta-catenin-TCF complex

A protein complex that contains beta-catenin and a member of the T-cell factor (TCF)/lymphoid enhancer binding factor (LEF) family of transcription factors.


oligosaccharyltransferase complex

A protein complex that is found in the endoplasmic reticulum membrane of eukaryotes and transfers lipid-linked oligosaccharide precursor to asparagine residues on nascent proteins. In yeast, the complex includes at least nine different subunits, whereas in mammalian cells at least three different forms of the complex have been detected.


CMG complex

A protein complex that contains the GINS complex, Cdc45p, and the heterohexameric MCM complex, and that is involved in unwinding DNA during replication.


mating projection tip polarisome

Protein complex that has a role in determining cell polarity, found at the tip of the mating projection in unicellular fungi exposed to mating pheromone.


Scrib-APC-beta-catenin complex

A protein complex that contains the Scribble protein (a cell polarity determinant), the tumor suppressor protein adenomatous polyposis coli (APC), and beta-catenin; may be involved in the control of cell proliferation.


collagen type XXI trimer

A collagen homotrimer of alpha1(XXI) chains; type XXI collagen triple helices found in the extracellular matrix component of blood vessel walls and in the cytoplasm of cultured human aortic smooth muscle.


RNA polymerase III complex

RNA polymerase III, one of three nuclear DNA-directed RNA polymerases found in all eukaryotes, is a multisubunit complex; typically it produces 5S rRNA, tRNAs and some of the small nuclear RNAs. Two large subunits comprise the most conserved portion including the catalytic site and share similarity with other eukaryotic and bacterial multisubunit RNA polymerases. The remainder of the complex is composed of smaller subunits (generally ten or more), some of which are also found in RNA polymerase I and others of which are also found in RNA polymerases I and II. Although the core is competent to mediate ribonucleic acid synthesis, it requires additional factors to select the appropriate template.


small-subunit processome

A large ribonucleoprotein complex that is an early preribosomal complex. In S. cerevisiae, it has a size of 80S and consists of the 35S pre-rRNA, early-associating ribosomal proteins most of which are part of the small ribosomal subunit, the U3 snoRNA and associated proteins.


synaptobrevin 2-SNAP-25-syntaxin-1a-complexin II complex

A SNARE complex that contains synaptobrevin 2 (VAMP2), SNAP-25, syntaxin 1a, and complexin II (or orthologs thereof).


Hpa2 acetyltransferase complex

A tetrameric protein complex capable of acetyltransferase activity. It can catalyze the transfer of an acetyl group from acetyl-CoA to an acceptor residue on histone H-3, histone H-4, or on polyamines. The complex is also capable of acetylating certain small basic proteins. The two Hpa2 dimers that make up the tetramer are held together by interactions between the bound acetyl-CoA molecules.


A protein complex that consists of an alphav-beta3 integrin complex bound to thrombospondin.


ferroxidase complex

A protein complex which is capable of ferroxidase activity.


chromatin silencing complex

Any protein complex that mediates changes in chromatin structure that result in transcriptional silencing.


nBAF complex

A SWI/SNF-type complex that is found in post-mitotic neurons, and in human contains actin and proteins encoded by the ARID1A/BAF250A or ARID1B/BAF250B, SMARCD1/BAF60A, SMARCD3/BAF60C, SMARCA2/BRM/BAF190B, SMARCA4/BRG1/BAF190A, SMARCB1/BAF47, SMARCC1/BAF155, SMARCE1/BAF57, SMARCC2/BAF170, DPF1/BAF45B, DPF3/BAF45C, ACTL6B/BAF53B genes. The nBAF complex along with CREST plays a role regulating the activity of genes essential for dendrite growth.


unconventional myosin complex

A portmanteau term for myosins other than myosin II.


NuRD complex

An approximately 2 MDa multi-subunit complex that exhibits ATP-dependent chromatin remodeling activity in addition to histone deacetylase (HDAC) activity, and has been shown to establish transcriptional repression of a number of target genes in vertebrates, invertebrates and fungi. Amongst its subunits, the NuRD complex contains histone deacetylases, histone binding proteins and Mi-2-like proteins.


collagen type XXV trimer

A collagen homotrimer of alpha1(XXV) chains; type XXV collagen triple helices span the plasma membrane.


PSII associated light-harvesting complex II, peripheral complex

Pigment-protein complex primarily associated to PSII in plants, green algae and cyanobacteria. Involved in state transitions that cause migration to PSI under certain environmental conditions such as high light.


BBSome

A ciliary protein complex involved in cilium biogenesis. It consists of at least seven Bardet-Biedl syndrome (BBS) proteins and BBIP10. It moves in association with IFT trains through cilia (likely as an IFT-A/B adaptor or cargo), and is required for the integrity of IFT-A and IFT-B.


GATOR2 complex

A multiprotein subcomplex of the GATOR complex that regulates TORC1 signaling by interacting with the Rag GTPase. In human, this complex consists of WDR24, WDR59, MIOS, SEH1L, and SEC13. In S. cerevisiae, this complex is referred to as SEACAT and contains the Sea2p, Sea3p, Sea4p, Seh1p, Sec13p proteins.


PDX1-PBX1b-MRG1 complex

A protein complex that contains the homeodomain proteins PDX1, PBX1b and MRG1 (MEIS2) and is involved in the transcriptional regulation of pancreatic acinar cell-specific genes.


APC-IQGAP1-Cdc42 complex

A protein complex that contains the tumor suppressor protein adenomatous polyposis coli (APC), the small GTPase Cdc42, and the Rac1 and Cdc42 effector IQGAP1; may play a role in cytoskeleton organization and cell migration.


beta-N-acetylhexosaminidase complex

A protein complex which is capable of beta-N-acetylhexosaminidase activity.


alpha4-beta1 integrin-paxillin complex

A protein complex that consists of an alpha4-beta1 integrin complex bound to paxillin.


viral RNA-directed RNA polymerase complex

A virus-specific protein complex that possesses RNA-dependent RNA polymerase activity and replicates the genome of an RNA virus.


myosin XV complex

A myosin complex containing a class XV myosin heavy chain and associated light chains. Myosin XV is single headed, and has a large extension (1200aa) at the N-terminus of the motor domain, two IQ motifs and a tail with a similar domain structure to that of the tail of myosin VII.


plasma membrane respiratory chain complex III

A part of the respiratory chain located in the plasma membrane, containing about 10 polypeptide subunits including four redox centers: cytochrome b/b6, cytochrome c1 and an 2Fe-2S cluster. Catalyzes the oxidation of ubiquinol by oxidized cytochrome c1. Examples of this component are found in bacterial species.


nuclear proteasome regulatory particle, base subcomplex

The subunits of the regulatory particle that directly associate with the core complex of a proteasome located in the nucleus of a cell.


cytosolic proteasome regulatory particle, base subcomplex

The subcomplex of the proteasome regulatory particle that directly associates with the proteasome core complex located in the cytosol of the cell.


exoribonuclease complex

A protein complex which is capable of exoribonuclease activity.


polysomal ribosome

A ribosome bound to mRNA that forms part of a polysome.


glutamate synthase complex (NADPH)

A complex that possesses glutamate synthase (NADPH) activity.


DNA recombinase auxiliary factor complex

A protein complex that binds to a recombinase and incrseases its activity.


protein C inhibitor-PLAU complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and urokinase-type plasminogen activator (PLAU); formation of the complex inhibits the serine protease activity of urokinase-type plasminogen activator.


H-NS-Hha complex

A trimeric protein complex made up of an H-NS homodimer and an Hha monomer. In Enterobacteriaceae, this complex negatively regulates transcription of a range of genes.


clathrin vesicle coat

A clathrin coat found on a vesicle.


succinate dehydrogenase complex

A multimeric complex which consists of flavoprotein (subunit A ; InterPro:IPR003952), iron-sulfur protein (subunit B) and membrane-bound cytochrome b560 (subunit C; InterPro:IPR000701). In some Archaea, the membrane-bound subunits (C or C and D) do not necessarily contain heme. Membrane-bound subunits can bind or react with quinones.


integrin alpha6-beta4 complex

An integrin complex that comprises one alpha6 subunit and one beta4 subunit.


DUBm complex

A protein complex that forms part of SAGA-type complexes SAGA and SLIK, and mediates deubiquitination of histone H2B. In S. cerevisiae, the DUBm consists of the proteins Ubp8p, Sgf11p, Sus1p, and Sgf73p.


chloroplast ATP synthase complex

The protein complex that catalyzes the phosphorylation of ADP to ATP in chloroplasts.


alpha6-beta4 integrin-CD9 complex

A protein complex that consists of an alpha6-beta4 integrin complex bound to the cell surface protein CD9.


SUMO-targeted ubiquitin ligase complex

A nuclear ubiquitin ligase complex that specifically targets SUMOylated proteins; the complex is formed of homodimers or heterodimers of RNF4 family ubiquitin ligases and is conserved in eukaryotes.


dolichyl-phosphate-mannose-protein mannosyltransferase Pmt5p-Pmt3p dimer complex

A protein dimer complex that possesses dolichyl-phosphate-mannose-protein mannosyltransferase activity and, in S. cerevisiae, is composed of Pmt5p-Pmt3p.


Swi5-Swi2 complex

A protein complex involved that contains proteins known in Schizosaccharomyces as Swi5 monomers and Swi2, and is involved in mating type switching.


CHD-type complex

A SWI/SNF-type complex that contains a subunit from the CHD(Chromodomain helicase DNA-binding) family. The CHD family is characterized by two signature sequence motifs: tandem chromodomains located in the N-terminal region, and the SNF2-like ATPase domain located in the central region of the protein structure.


ATR-ATRIP complex

A protein complex that contains the protein kinase ATR and ATR-interacting protein (ATRIP) and binds single-stranded DNA; ssDNA binding affinity is increased in the presence of replication protein A.


viral portal complex

A multimeric ring of proteins through which the DNA enters and exits the viral capsid.


R2TP complex

A highly conserved protein complex comprised of two ATP-dependent DNA helicases (Rvb1p and Rvb2p in yeast, Pontin52 and Reptin52 in humans), Pih1p in yeast or PIH1D1 in humans, and Tah1 in yeast or RPAP3 in humans. The complex associates with Hsp90 and is thought to have a role in assembly of large protein or protein/nucleic acid complexes. In this role it is involved in multiple processes such as box C/D snoRNP biogenesis, phosphatidylinositol-3 kinase-related protein kinase (PIKK) signaling, RNA polymerase II assembly, and others.


phosphatase complex

A protein complex which is capable of phosphatase activity.


sulfate adenylyltransferase complex (ATP)

An enzyme complex that catalyzes the formation adenylylsulfate from sulfate and ATP.


methyl accepting chemotaxis protein complex

A transmembrane protein complex that consists of multiple methyl-accepting chemoreceptor protein subunits, a histidine kinase and a connector protein and which functions in the regulation of flagellar rotary motor activity in response to an external chemical stimulus.


PKM2 protein kinase complex

A protein complex capable of phosphorylating a large number of protein targets. Contributes to cell proliferation under glycose starvation conditions. In human, the complex is present as a dimer.


glycine-tRNA ligase complex

A multimeric enzyme complex which, in bacteria, is usually a tetramer of two alpha and two beta chains and in eukaryotes, is usually a homodimer. Functions in the ligation of glycine and tRNA(Gly) to form glycyl-tRNA(Gly).


A complex that possesses dolichyl-phosphate-mannose-protein mannosyltransferase activity; usually includes members of the PMT1 and PMT2 protein subfamilies.


mitochondrial processing peptidase complex

A protein complex consisting of a regulatory subunit (alpha-MPP) and a catalytic subunit (beta-MPP) that catalyzes the release of N-terminal targeting peptides from precursor proteins imported into the mitochondrion.


SREBP-SCAP complex

A protein complex formed by the association of sterol regulatory element binding protein (SREBP) and SREBP-cleavage-activating protein (SCAP) in the ER membrane; in the absence of sterols, the SREBP-SCAP complex is packaged into COPII vesicles and travels to the Golgi apparatus to be processed.


thrombospondin complex

A homotrimeric or homopentameric glycoprotein that functions at the interface of the cell membrane and the extracellular matrix through its interactions with proteins and proteoglycans, such as collagens, integrins and fibronectin, to regulate matrix structure and cellular behaviour.


FHF complex

A protein complex that is composed of AKTIP/FTS, FAM160A2/p107FHIP, and one or more members of the Hook family of proteins, HOOK1, HOOK2, and HOOK3. The complex is thought to promote vesicle trafficking and/or fusion, and associates with the homotypic vesicular sorting complex (the HOPS complex).


A protein-lipid-RNA complex containing separate high-density lipoprotein (HDL), lipid and RNA molecules. Separate in this context means not covalently bound to each other.


FACIT collagen trimer

A collagen trimer that associates with collagen fibrils and consists of collagen monomers that contain two or more relatively short triple-helical domains connected by non-triple-helical sequences.


A protein complex that is involved in the transfer of the four mannoses in the GPI-anchor precursor. In yeast S. cerevisiae this complex consists of Pbn1p and Gpi14p and in rat this complex consists of PIG-X and PIG-M.


complex of collagen trimers

A complex of collagen trimers such as a fibril or collagen network.


alphaIIb-beta3 integrin-CD9 complex

A protein complex that consists of an alphaIIb-beta3 integrin complex bound to the cell surface protein CD9.


T cell receptor complex

A protein complex that contains a disulfide-linked heterodimer of T cell receptor (TCR) chains, which are members of the immunoglobulin superfamily, and mediates antigen recognition, ultimately resulting in T cell activation. The TCR heterodimer is associated with the CD3 complex, which consists of the nonpolymorphic polypeptides gamma, delta, epsilon, zeta, and, in some cases, eta (an RNA splice variant of zeta) or Fc epsilon chains.


plastid-encoded plastid RNA polymerase complex A

A plastid-encoded DNA-directed RNA polymerase complex that resembles eubacterial multisubunit RNA polymerases, with a core composed of alpha, beta, and beta-prime subunits. An additional subunit, a sigma factor, is required for promoter recognition. PEP-A is generated from the PEP-B form during chloroplast maturation to generate a complex composed of at least thirteen polypeptides that is not sensitive to the antibiotic rifampicin, like its precursor form the PEP-B complex.


B-WICH complex

A chromatin remodeling complex that positively regulates histone H3 acetylation, in particular H3K9, by recruiting histone acetyltransferases to rDNA gene regions. Located in the nucleolus where it assembles on RNA Polymerase I (Pol I) and possibly on RNA Polymerase III (Pol III) promoter and coding regions during early G1 phase and activates the post-initiation phases of Pol I transcription. May also activate RNA Polymerase II (Pol II) gene transcription. In mammals, B-WICH contains the WICH complex core of BAZ1B and SMARCA5, additional protein subunits and possibly rRNAs. Although it contains several catalytic subunits it is not clear which functions are carried out by the complex itself.


atf1-pcr1 complex

A heterodimeric transcription factor complex composed of the bZIP proteins atf1 and pcr1. The heterodimer binds m26 sites (homologous to CRE).


MdtBC Complex

A protein complex containing two transmembrane subunits; a MdtB dimer and one unit of MdtC. Capable of exporting substrates across the cell membrane. Involved in conferring antibiotic resistance of Gram-negative bacteria by transporting drugs across the membrane.


non-canonical inflammasome complex

An inflammasome complex containing CASP4, known as caspase-11 (Casp11) in mouse, which assembles upon cytosolic lipopolysaccharide-binding and directly activates Gasdermin-D (GSDMD).


collagen type VI trimer

A collagen heterotrimer containing type VI alpha chains in alpha1(VI)alpha2(VI)alpha3(VI) trimers; type VI collagen triple helices associate to form beaded fibrils.


pre-B cell receptor complex

An immunoglobulin-like complex that is present in at least the plasma membrane of pre-B cells, and that is composed of two identical immunoglobulin heavy chains and two surrogate light chains, each composed of the lambda-5 and VpreB proteins, and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins.


intraciliary transport particle B

The larger subcomplex of the intraciliary transport particle; characterized complexes have molecular weights around 550 kDa.


alpha7-beta1 integrin-laminin alpha-2 complex

A protein complex that consists of an alpha7-beta1 integrin complex bound to laminin alpha-2.


GABA receptor complex

A protein complex which is capable of GABA receptor activity. Upon binding of gamma-aminobutyric acid (GABA) it transmits the signal from one side of the membrane to the other to initiate a change in cell activity. Major inhibitory receptor in vertebrate brain. Also found in other vertebrate tissues, invertebrates and possibly in plants. Effective benzodiazepine receptor.


cytochrome b6f complex

Complex that transfers electrons from reduced plastoquinone to oxidized plastocyanin and translocates protons from the stroma to the lumen. The complex contains a core structure of three catalytic subunits: cytochrome b, the Rieske iron sulfur protein (ISP), and cytochrome f, which are arranged in an integral membrane-bound dimeric complex; additional subunits are present, and vary among different species.


Doa10p ubiquitin ligase complex

A multiprotein complex that recognizes and ubiquitinates membrane proteins with misfolded cytosolic domains during ER-associated protein degradation (ERAD). In S. cerevisiae, this complex contains the ubiquitin ligase Ssm4p/Doa10p.


transmembrane transporter complex

A transmembrane protein complex which enables the transfer of a substance from one side of a membrane to the other.


A SNARE complex that contains synaptobrevin 2 (VAMP2), SNAP-25, syntaxin 3, and a complexin (or orthologs thereof).


proteasome regulatory particle, lid subcomplex

The subcomplex of the proteasome regulatory particle that forms the peripheral lid, which is added on top of the base subcomplex.


pyruvate kinase complex

A protein complex which is capable of pyruvate kinase activity.


NuA3a histone acetyltransferase complex

A NuA3 complex that catalyzes the acetylation of Histone H3. In S. cerevisiae, this complex consists of Eaf6p, Nto1p, Sas3p, Taf14p, Yng1p and associates with H3K4me3 using Yng1p.


Asi complex

A nuclear ubiquitin ligase multiprotein complex located in the inner nuclear membrane (INM) that recognizes and ubiquitinates misfolded INM proteins and also some proteins involved in sterol biosynthesis, during ER-associated protein degradation (ERAD). In S. cerevisiae, this complex contains the ubiquitin ligases Asi1p and Asi3p.


curli secretion complex

A protein-containing complex that serves as a channel for the secretion of curli. Curli are a fibers that serve as a major component of the extracellular matrix of pellicle biofilms.


interphase SIN signalling complex

A SIN signalling complex associated with the old mitotic spindle pole body during interphase and early M-phase and characterised by the presence active ubiquitin ligase (Dma1 in fission yeast) and GTPase activator (Spg1 in fission yeast) to inactivate SIN signalling.


RSC-type complex

A SWI/SNF-type complex that contains a bromodomain containing-protein, such as yeast Rsc1 or Rsc4 or mammalian PB1/BAF180. The RSC complex is generally recruited to RNA polymerase III promoters and is specifically recruited to RNA polymerase II promoters by transcriptional activators and repressors; it is also involved in non-homologous end joining.


A heterodimeric complex between the tyrosine kinase receptor ERBB2 and a ligand-activated epidermal growth factor receptor (EGFR/ERBB1). ERBB2, which does not bind any known ligand, is activated through formation of a heterodimer with another ligand-activated ERBB family member such as EGFR.


RENT complex

A protein complex that mediates transcriptional silencing at the rDNA locus (the name derives from regulator of nucleolar silencing and telophase). In Saccharomyces the complex contains Net1p, Sir2p, Cdc14p, and at least one more subunit.


nonsense-mediated decay complex

A highly conserved protein complex that recognises and elicits the rapid degradation of mRNAs in which an amino-acid codon has changed to a nonsense codon; occurs when the 3' end is not protected by a 3'-poly(A) tail; degradation proceeds in the 3' to 5' direction.


type I interferon receptor complex

A heterodimeric protein complex that binds a type I interferon and transmits the signal across the membrane into the cell. Consists of an alpha subunit (IFNAR1) and a beta subunit (IFNAR2).


procollagen-proline 4-dioxygenase complex, alpha(III) type

A procollagen-proline 4-dioxygenase complex that contains alpha subunits of the type III isoform.


centriolar subdistal appendage

A protein complex which assembles on the mother centriole during cilium formation, adjacent and proximal to a centriolar distal appendage. In human, it contains ODF2, CNTRL, NIN, CCDC120c and CCDC68.


LUBAC complex

A ubiquitin ligase complex that catalyzes linear head-to-tail polyubiquitin conjugation on its targets. In human the complex consists of RBCK1, RNF31 and SHARPIN, and has an MW of approximately 600 kDa, suggesting a heteromultimeric assembly of its subunits. LUBAC stands for Linear Ubiquitin Chain Assembly Complex.


transverse flagellum

A motile cilium found in dinoflagellates. It coils around the cell and provides the forward thrust for motility. It is often contained in a furrow called the cingulum, and emerges from a flagellar pore located in the cingulum.


photosystem II reaction center

An integral membrane complex containing P680, the chlorophyll a molecule that functions as a primary electron donor. In the light, functioning as a water-plastoquinone oxidoreductase, it transfers electrons from water to plastoquinone.


lipopolysaccharide transport system

A protein-containing complex that functions to transport lipopolysaccharide from its site of synthesis at the cytoplasmic membrane across the periplasm to the outer membrane in an ATP-dependent manner.


MTREC complex

Protein complex formed by an RNA binding protein Red1, an RNA helicase Mtl1, Red5, Rmn1, Iss10/Pir1, and Ars2/Pir2. This complex is required for the recruitment of the nuclear exosome to Mmi1 nuclear focus. It is likely related to the human CBCN complex. This complex is also known as RNA silencing (NURS) complex.


bacterial degradosome

The degradosome is a protein complex playing a key role in mRNA degradation and RNA processing. It includes a RNA helicase, a 3'-5' phosphate-dependent PNPase and a RNase E bound-enolase.


3-phenylpropionate dioxygenase complex

Enzyme complex consisting of four proteins: the two subunits of the hydroxylase component (hcaE and hcaF), a ferredoxin (hcaC) and a ferredoxin reductase (hcaD). Converts 3-phenylpropionic acid (PP) into cis-3-(3-carboxyethyl)-3,5-cyclohexadiene-1,2-diol (PP-dihydrodiol).


mitotic cohesin complex

A cohesin complex that mediates sister chromatid cohesion during mitosis; has a subunit composition distinct from that of the meiotic cohesin complex.


intraciliary transport particle

A nonmembrane-bound oligomeric protein complex that participates in bidirectional transport of molecules (cargo) along axonemal microtubules.


DnaA-Dps complex

A protein complex that negatively regulates strand-opening at the origin of replication, thereby interfering with replication initiation. This complex is thought to be involved in the regulation of replication under oxidative stress conditions. In E. coli, this complex is composed of DnaA and Dps.


xanthine dehydrogenase complex

A homodimeric protein complex having xanthine dehydrogenase activity.


epsilon DNA polymerase complex

A heterotetrameric DNA polymerase complex that catalyzes processive DNA synthesis in the absence of PCNA, but is further stimulated in the presence of PCNA. The complex contains a large catalytic subunit and three small subunits, and is best characterized in Saccharomyces, in which the subunits are named Pol2p, Dpb2p, Dpb3p, and Dpb4p. Some evidence suggests that DNA polymerase epsilon is the leading strand polymerase; it is also involved in nucleotide-excision repair and mismatch repair.


electron transfer flavoprotein complex

A protein complex facilitating the electron transfer from an acyl-CoA molecule to ubiquinone via its flavin adenine dinucleotide (FAD) cofactor. Usually contains an alpha and a beta subunit and the structural cofactor adenosine monophosphate (AMP). Part of a system that oxidizes an acyl-CoA molecule and reduces ubiquinone and other acceptors in the electron transport system.


Wnt signalosome

A multiprotein protein complex containing membrane-localized Wnt receptors and cytosolic protein complexes, which is capable of transmitting the Wnt signal. Contains at least a Wnt protein, LRP5 or LRP6, a member of the Frizzled (Fz) family, Axin and and a Dishevelled (DVL) protein.


BRE1 E3 ubiquitin ligase complex

A homodimeric protein complex composed of the E3 ubiquitin-protein ligase BRE1. Plays a role in regulating association of RNA polymerase II with active genes.


SeqA-DNA complex

A protein-DNA complex that contains an oligomer of SeqA bound to GATC sites in methylated or newly-synthesized, hemi-methylated double-stranded DNA, with preference for the latter. Binding of SeqA to hemimethylated DNA sequesters oriC, prevents re-methylation of DNA by Dam and in turn stops premature re-initiation of replication during one replication cycle.


ecdysone receptor holocomplex

A heterodimeric complex containing the products of the insect genes Ecdysone receptor (EcR) and ultraspiracle (usp). Binding of ecdysone promotes association between the two subunits, and the receptor complex then initiates molting and metamorphosis by binding DNA and regulating the transcription of target genes.


mitochondrial respiratory chain complex III

A protein complex located in the mitochondrial inner membrane that forms part of the mitochondrial respiratory chain. Contains about 10 polypeptide subunits including four redox centers: cytochrome b/b6, cytochrome c1 and an 2Fe-2S cluster. Catalyzes the oxidation of ubiquinol by oxidized cytochrome c1.


Isw1b complex

An Isw1 complex that binds DNA and has nucleosome-stimulated ATPase activity. In S. cerevisiae, contains an Isw1p ATPase subunit in complex with Ioc2p and Ioc4p.


left anterior flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It originates at the left anterior basal body, extends laterally through the cytoplasm, crosses the right anterior axoneme, and exits as a membrane-bound flagellum on the anterior left side of the cell.


FAR/SIN/STRIPAK complex

A conserved protein phosphatase type 2A complex which contains a protein phosphatase type 2A, a protein phosphatase regulatory subunit, a striatin, an FHA domain protein and other subunits (at least six proteins). In fission yeast this complex negatively regulate the septation initiation network at the spindle pole body.


U2AF complex

A heterodimeric protein complex consisting of conserved large and small U2AF subunits that contributes to spliceosomal RNA splicing by binding to consensus sequences at the 3' splice site. U2AF is required to stabilize the association of the U2 snRNP with the branch point.


Tec1p-Ste12p-Dig1p complex

A multiprotein complex that is involved in the transcriptional regulation of primarily filamentation genes, but also mating genes, in the yeast S. cerevisiae.


activin responsive factor complex

A transcriptionally active complex that binds to an activin response element (ARE) in the promoter of target genes, and is composed of two SMAD2 proteins, one SMAD4 protein and a Forkhead activin signal transducer (FAST) transcription factor.


beta-catenin destruction complex

A cytoplasmic protein complex containing glycogen synthase kinase-3-beta (GSK-3-beta), the adenomatous polyposis coli protein (APC), and the scaffolding protein axin, among others; phosphorylates beta-catenin, targets it for degradation by the proteasome.


integrin alphaIIb-beta3 complex

An integrin complex that comprises one alphaIIb subunit and one beta3 subunit.


viral transcriptional complex

Specific locations and structures in the virus infected cell involved in transcribing the viral genome.


translation preinitiation complex

A ribonucleoprotein complex that contains the small ribosomal subunit, a translation initiation ternary complex (i.e. an initiator tRNA, GTP, and an IF2 or eIF2 complex), and an mRNA.


IgD immunoglobulin complex, circulating

A protein complex composed of two identical immunoglobulin heavy chains of the IgD isotype and two identical immunoglobulin light chains, held together by disulfide bonds, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph.


transcription factor TFIIIC2 complex

A transcription factor complex that forms part of the TFIIIC complex, observed in human; composed of five subunits (GTF3C1/hTFIIIC220/TFIIICalpha, GTF3C2/hTFIIIC110/TFIIICbeta, GTF3C3/hTFIIIC102/TFIIICgamma, GTF3C4/hTFIIIC90/TFIIICdelta and GTF3C5/hTFIIIC63/TFIIICepsilon in human) that together recognize the type 2 RNA polymerase III promoter.


nuclear origin of replication recognition complex

A multisubunit complex that is located at the replication origins of a chromosome in the nucleus.


phosphatidylinositol 3-kinase complex, class IB

A class I phosphatidylinositol 3-kinase complex that possesses 1-phosphatidylinositol-4-phosphate 3-kinase activity; comprises a catalytic class IB phosphoinositide 3-kinase (PI3K) subunit and an associated regulatory subunit that is larger than, and unrelated to, the p85 proteins present in class IA complexes. Class IB PI3Ks are stimulated by G-proteins and do not interact with the SH2-domain containing adaptors that bind to Class IA PI3Ks.


G-protein beta/gamma-Raf-1 complex

A protein complex formed by the association of the serine-threonine protein kinase Raf-1 with the beta and gamma subunits of a heterotrimeric G protein.


ubiquitin conjugating enzyme complex

Any complex that possesses ubiquitin conjugating enzyme activity.


sex chromatin

Chromatin that is part of a sex chromosome.


NADH dehydrogenase complex (plastoquinone)

An NADH dehydrogenase complex that catalyzes the transfer of electrons to plastoquinone. The complex is involved in the non-photochemical reduction of plastoquinones and the cyclic electron transport around photosystem I, and is found in plastid thylakoids.


DiaA complex

A homotetrameric protein complex consisting of a symmetrical pair of DiaA homodimers. Facilitates DnaA binding to the origin of replication during replication initiation.


ribosomal subunit

Either of the two subunits of a ribosome: the ribosomal large subunit or the ribosomal small subunit.


IgM B cell receptor complex

An IgM immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of the IgM isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins.


GATOR1 complex

A GTPase-activating protein (GAP) complex that regulates TORC1 signaling by interacting with the Rag GTPase. In human, the GATOR1 complex consists of DEPDC5, NPRL2, and NPRL3. In S. cerevisiae, this complex is referred to as SEACIT and contains the Iml1p, Npr2p, and Npr3p proteins.


L-type voltage-gated calcium channel complex

A type of voltage-dependent calcium channel responsible for excitation-contraction coupling of skeletal, smooth, and cardiac muscle. 'L' stands for 'long-lasting' referring to the length of activation.


CD20-Lck-Lyn-Fyn complex

A protein complex that contains the cell-surface protein CD20 and the Src family tyrosine kinases Lck, Lyn and Fyn.


alkanesulfonate monooxygenase complex

A protein complex capable of alkanesulfonate monooxygenase activity. Involved in the utilization of alkanesulfonates as sulfur sources under conditions of sulfate or cysteine starvation, catalyzing the conversion of alkanesulfonates into aldehydes and sulfite. In E.coli the complex consists of a SsuD tetramer.


MAML2-RBP-Jkappa-ICN2 complex

A protein complex that consists of the intracellular domain of Notch2 (ICN2), the DNA-binding transcription factor RBP-Jkappa, and the transcriptional coactivator Mastermind-like-2 (MAML2); the complex is involved in transcriptional activation in response to Notch-mediated signaling.


membrane attack complex

A protein complex produced by sequentially activated components of the complement cascade inserted into a target cell membrane and forming a pore leading to cell lysis via ion and water flow.


clathrin coat of trans-Golgi network vesicle

A clathrin coat found on a vesicle of the trans-Golgi network.


Cdc24p-Far1p-Gbetagamma complex

A complex that forms at the cell cortex in response to pheromone treatment and is required for the polarized growth of haploid yeast cells towards a mating partner during yeast mating. In the yeast Saccharomyces cerevisiae, this complex consists of Cdc24p, Far1p, Ste4p (G-protein beta subunit) and Ste18p (G-protein gamma subunit).


BRCA1-A complex

A protein complex that contains the BRCA1-BARD1 heterodimer, RAP80/UIMC1, BRCC3/BRCC36, BRE/BRCC45, FAM175A/CCDC98/Abraxas and MERIT40/NBA1, and specifically recognizes and binds K63-linked polyubiquitin chains present on histone H2A and H2AX at DNA damage sites.


Kv4.3-DPP6 channel complex

A voltage-gated potassium channel complex that contains the peptidase-related protein DPP6 associated with the channel via interaction with the Kv alpha subunit 4.3.


dihydrolipoyl dehydrogenase complex

A protein complex that possesses alpha-ketoglutarate dehydrogenase activity.


calcineurin complex

A heterodimeric calcium ion and calmodulin dependent protein phosphatase composed of catalytic and regulatory subunits; the regulatory subunit is very similar in sequence to calmodulin.


npBAF complex

A SWI/SNF-type complex that is found in neural stem or progenitor cells, and in human contains actin and proteins encoded by the ARID1A/BAF250A or ARID1B/BAF250B, SMARCD1/BAF60A, SMARCD3/BAF60C, SMARCA2/BRM/BAF190B, SMARCA4/BRG1/BAF190A, SMARCB1/BAF47, SMARCC1/BAF155, SMARCE1/BAF57, SMARCC2/BAF170, PHF10/BAF45A, ACTL6A/BAF53A genes. The npBAF complex is essential for the self-renewal/proliferative capacity of the multipotent neural stem cells.


TEAD-YAP complex

A transcription factor complex that is composed of the one DNA binding protein of the TEAD family and the transcriptional coactivator YAP.


cell envelope Sec protein transport complex

A transmembrane protein complex involved in the translocation of proteins across the cytoplasmic membrane. In Gram-negative bacteria, Sec-translocated proteins are subsequently secreted via the type II, IV, or V secretion systems. Sec complex components include SecA, D, E, F, G, Y and YajC.


inner dynein arm

Inner arm structure present on the outer doublet microtubules of ciliary and flagellar axonemes. The structure of inner dynein arms is complex and may vary within the axoneme. Inner dynein arms are heteromeric, comprising 8 different heavy chains and various subunits. Inner and outer dynein arms have different functions in the generation of microtubule-based motility.


9+0 motile cilium

A motile cilium where the axoneme has a ring of nine outer microtubule doublets but no central microtubules (and is therefore called a 9+0 axoneme).


cardiac Troponin complex

A complex of accessory proteins (cardiac troponin T, cardiac troponin I and cardiac troponin C) found associated with actin in cardiac muscle thin filaments; involved in calcium regulation important for muscle contraction.


G protein-coupled GABA receptor complex

A protein complex which is capable of G protein-coupled GABA receptor activity. In human, it is usually a heterodimer composed of GABA-B receptor subunits 1 and 2.


N-terminal protein acetyltransferase complex

A complex that catalyzes the transfer of an acetyl group to the N-terminal residue of a protein acceptor molecule.


interleukin-12 complex

A protein complex that is composed of an interleukin-12 alpha (p35, product of the IL12A gene) and an interleukin-12 beta subunit (p40, product of the IL12B gene) and is secreted into the extracellular space.


ERBB4-EGFR complex

A heterodimeric complex between the tyrosine kinase receptors ERBB4 (also called HER4) and epidermal growth factor receptor (EGFR/ERBB1).


histone acetyltransferase complex

A protein complex that possesses histone acetyltransferase activity.


exomer complex

A protein complex that forms a coat structure on vesicles involved in exocytosis of proteins from the trans-Golgi network to the cell surface; in Saccharomyces, the complex contains Chs5p, Chs6p, and Chs6p paralogues.


Hrd1p ubiquitin ligase ERAD-M complex

A multiprotein complex that recognizes and ubiquitinates proteins with misfolded membrane domains during ER-associated protein degradation (ERAD). In S. cerevisiae, this complex contains the ubiquitin ligase Hrd1p.