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

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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.


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.


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.


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.


icosahedral viral capsid, neck fiber

A fiber attached to the neck at the base of some icosahedral viral capsids.


viral capsid, turret

A turret-like appendage formed at the vertices of an icosahedral capsid.


viral capsid, fiber

A type of capsid decoration composed of fiber structures.


interleukin-3 receptor complex

A protein complex that binds interleukin-3; comprises an alpha and a beta subunit. The alpha chain is specific to the interleukin-3 receptor, whereas the beta chain is shared with the receptors for granulocyte-macrophage colony-stimulating factor and interleukin-5.


dystrobrevin complex

A protein complex comprising alpha- and beta-dystrobrevin; forms part of the dystrophin glycoprotein complex.


PAM complex, Tim23 associated import motor

Protein complex located on the matrix side of the mitochondrial inner membrane and associated with the TIM23 mitochondrial import inner membrane translocase complex (GO:0005744); ATPase motor activity to drive import of proteins into the mitochondrial matrix.


root hair

A long, thin projection from a root epidermal cell that contains F-actin and tubulin, and a cell wall.


monomeric IgA immunoglobulin complex

A protein complex composed of two identical immunoglobulin heavy chains of an IgA 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.


cytosolic oxoglutarate dehydrogenase complex

A cytosolic complex of multiple copies of three enzymatic components: oxoglutarate dehydrogenase (lipoamide) (E1), dihydrolipoamide S-succinyltransferase (E2) and dihydrolipoamide dehydrogenase (E3); catalyzes the overall conversion of 2-oxoglutarate to succinyl-CoA and carbon dioxide (CO2).


oxoglutarate dehydrogenase complex

A complex of multiple copies of three enzymatic components: oxoglutarate dehydrogenase (lipoamide) (E1), dihydrolipoamide S-succinyltransferase (E2) and dihydrolipoamide dehydrogenase (E3); catalyzes the overall conversion of 2-oxoglutarate to succinyl-CoA and carbon dioxide (CO2).


RNA polymerase complex

Any complex that possesses RNA polymerase activity; generally comprises a catalytic subunit and one or more additional subunits.


RNA polymerase I complex

RNA polymerase I, one of three nuclear DNA-directed RNA polymerases found in all eukaryotes, is a multisubunit complex; typically it produces rRNAs. 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 III and others of which are also found in RNA polymerases II and III. Although the core is competent to mediate ribonucleic acid synthesis, it requires additional factors to select the appropriate template.


RNA-directed RNA polymerase complex

A protein complex that possesses RNA-directed RNA polymerase activity.


RNA polymerase II, holoenzyme

A nuclear DNA-directed RNA polymerase complex containing an RNA polymerase II core enzyme as well as additional proteins and transcription factor complexes, that are capable of promoter recognition and transcription initiation from an RNA polymerase II promoter in vivo. These additional components may include general transcription factor complexes TFIIA, TFIID, TFIIE, TFIIF, or TFIIH, as well as Mediator, SWI/SNF, GCN5, or SRBs and confer the ability to recognize promoters.


plastid-encoded plastid RNA polymerase complex B

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-B is distinguished from PEP-A by its sensitivity to the antibiotic rifampicin. PEP-B is found in both etioplasts and chloroplasts, but is the predominate form in etioplasts. It forms the core of the PEP-A form; the conversion from PEP-B to PEP-A occurs during chloroplast maturation.


nuclear RNA-directed RNA polymerase complex

A complex required for RNAi mediated heterochromatin assembly. In S. pombe this contains RNA-directed RNA polymerase, a putative helicase and a protein containing a pap25 associated domain.


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.


TERT-RMRP complex

A ribonucleoprotein complex that has RNA-directed RNA polymerase (RdRP) activity, and is composed of telomerase reverse transcriptase (TERT) and the non-coding RNA component of mitochondrial RNA processing endoribonuclease (RMRP).


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.


mitochondrial DNA-directed RNA polymerase complex

A DNA-directed RNA polymerase complex located in the mitochondrion. Mitochondrial RNA polymerase is composed of two subunits, a catalytic core, which resembles the enzymes from bacteriophage T7 and T3, and a specificity factor required for promoter recognition, which is similar to members of the eubacterial sigma factor family. In S. cerevisiae, these are encoded by the nuclear genes RPO41 and MTF1 and the specificity factor, required for promoter recognition and initiation, is not present in the elongating form.


alpha DNA polymerase:primase complex

A complex of four polypeptides, comprising large and small DNA polymerase alpha subunits and two primase subunits, which are capable of catalyzing the synthesis of an RNA primer on the lagging strand of replicating DNA and the subsequent synthesis of a smal stretch of DNA. The smaller of the two primase subunits alone can catalyze oligoribonucleotide synthesis.


RNA polymerase IV complex

RNA polymerase IV is a multisubunit RNA polymerase complex found in the nucleus of plants and involved in accumulation of siRNAs and in DNA methylation-dependent silencing of endogenous repeated sequences. Pol IV is composed of subunits that are paralogous or identical to the 12 subunits of Pol II. The largest and second-largest subunits of Pol IV are the catalytic subunits and share similarity with the corresponding subunits of other eukaryotic and bacterial multisubunit RNA polymerases. The second largest subunit is also found in RNA polymerase V, while the largest subunit is found only in RNAP IV complex.


plastid-encoded plastid RNA polymerase complex

An RNA polymerase complex containing polypeptides encoded by the plastid genome. Plastid-encoded DNA-directed RNA polymerases resemble eubacterial multisubunit RNA polymerases, with a core composed of alpha, beta, and beta-prime subunits. Some forms contain multiple additional subunits. An additional sigma factor subunit is required for promoter recognition.


nuclear DNA-directed RNA polymerase complex

A protein complex, located in the nucleus, that possesses DNA-directed RNA polymerase activity.


RNA polymerase II, core complex

RNA polymerase II, one of three nuclear DNA-directed RNA polymerases found in all eukaryotes, is a multisubunit complex; typically it produces mRNAs, snoRNAs, and some of the snRNAs. Two large subunits comprise the most conserved portion including the catalytic site and share similarity with other eukaryotic and bacterial multisubunit RNA polymerases. The largest subunit of RNA polymerase II contains an essential carboxyl-terminal domain (CTD) composed of a variable number of heptapeptide repeats (YSPTSPS). The remainder of the complex is composed of smaller subunits (generally ten or more), some of which are also found in RNA polymerases I and III. Although the core is competent to mediate ribonucleic acid synthesis, it requires additional factors to select the appropriate template.


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.


Tic complex

The translocon of the inner envelope of chloroplasts, which facilitates the import of proteins across the chloroplast inner membrane.


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.


signal recognition particle, endoplasmic reticulum targeting

A ribonucleoprotein particle of 325 kDa composed of a 7S (300 nucleotide) RNA molecule and a complex of six different polypeptides. This binds both to the N-terminal signal peptide for proteins destined for the endoplasmic reticulum as they emerge from the large ribosomal subunit and also to the ribosome. This binding arrests further translation thereby preventing the proteins from being released into the cytosol. The SRP-ribosome complex then diffuses to the endoplasmic reticulum where it is bound to the signal recognition particle receptor, which allows resumption of protein synthesis and facilitates the passage of the growing polypeptide chain through the translocon. Through a process involving GTP hydrolysis, the SRP-SRP receptor complex dissociates and SRP returns to the cytosol. Of the six polypeptides of SRP the 54 kDa subunit (SRP54) is the central player. It contains an N-terminal GTPase domain and a C-terminal domain that binds directly to the signal peptide and the SRP RNA. Examples of this component are found in Mus musculus, Saccharomyces cerevisiae and Arabidopsis thaliana.


rough endoplasmic reticulum membrane

The lipid bilayer surrounding the rough endoplasmic reticulum.


equatorial microtubule organizing center

A microtubule organizing center formed by a band of gamma-tubulin that is recruited to a circumferential band of F-actin at the midpoint of a cell and which nucleates microtubules from the cell division site at the end of mitosis.


left nucleus

One of the two nuclei found in Giardia species (trophozoite stage). It is located on the left side of the cell when viewed from the dorsal side.


telopode

A telopode is a plasma membrane bounded cell projection that is present on a telocyte and is tens to hundreds of microns long. Telopodes form a labyrinthine system communicating through gap junctions.


FNIP-folliculin RagC/D GAP

A heterodimeric complex that functions as a GTPase-Activating Protein (GAP) Complex for members of the Rag family of GTPases. In the budding yeast, this complex contains Lst4 and Lst7, while the orthologous mammalian complex contains follicular (FLCN) and either follicular interacting protein 1 (FNIP1) or FNIP2.


GTPase activator complex

A protein complex which is capable of GTPase activator activity.


Bfa1-Bub2 complex

A protein complex that acts as a two-component GTPase-activating protein for Tem1 GTPase, thus regulating a signal transduction cascade, called the mitotic exit network (MEN), which is required for mitotic exit and cytokinesis. Bub2/Bfa1 keeps Tem1 inactive until the spindle is properly oriented, thus inhibiting MEN activation.


A axonemal microtubule

A complete microtubule with 13 protofilaments that fuses with an incomplete microtubule called B tubule (containing 10 protofilaments only) to form an axonemal outer doublet. Inner and outer dynein arms, as well as the radial spoke, are attached to the A tubule.


supramolecular complex

A cellular component that consists of an indeterminate number of proteins or macromolecular complexes, organized into a regular, higher-order structure such as a polymer, sheet, network or a fiber.


lamin filament

Any of a group of intermediate-filament proteins that form the fibrous matrix on the inner surface of the nuclear envelope. They are classified as lamins A, B and C.


skeletal muscle myofibril

A myofibril of a skeletal muscle fiber.


dendritic microtubule

Any microtubule in a dendrite, a neuron projection.


fibronectin fibril

A supramolecular fiber formed from fibronectin molecules. The fibrils are 5 to 25nm in diameter and can form branched meshworks.


intraconoid microtubule

A microtubule located such that it threads through the conoid and projects through the polar ring.


supramolecular polymer

A polymeric supramolecular structure.


collagen network

A supramolecular complex that consists of collagen triple helices associated to form a network.


astral microtubule

Any of the spindle microtubules that radiate in all directions from the spindle poles and are thought to contribute to the forces that separate the poles and position them in relation to the rest of the cell.


kinetochore microtubule

Any of the spindle microtubules that attach to the kinetochores of chromosomes by their plus ends, and maneuver the chromosomes during mitotic or meiotic chromosome segregation.


post-anaphase array microtubule

Any microtubule that is part of a post-anaphase microtubule array.


mitotic spindle polar microtubule

Any of the mitotic spindle microtubules that come from each pole and overlap at the spindle midzone.


contractile fiber

Fibers, composed of actin, myosin, and associated proteins, found in cells of smooth or striated muscle.


smooth muscle contractile fiber

The contractile fiber of smooth muscle cells.


meiotic spindle astral microtubule

Any of the meiotic spindle microtubules that radiate in all directions from the spindle poles and are thought to contribute to the forces that separate the poles and position them in relation to the rest of the cell.


polymeric cytoskeletal fiber

A component of the cytoskeleton consisting of a homo or heteropolymeric fiber constructed from an indeterminate number of protein subunits.


actomyosin contractile ring actin filament

Any actin filament that is part of a actomyosin contractile ring.


polar microtubule

Any of the spindle microtubules that come from each pole and overlap at the spindle midzone. This interdigitating structure consisting of antiparallel microtubules is responsible for pushing the poles of the spindle apart.


collagen sheet

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


subpellicular microtubule

Singlet microtubule that lie underneath the inner membrane pellicle complex and emanate from the basal ring of the conoid.


microfibril

Extracellular matrix components occurring independently or along with elastin. Thought to have force-bearing functions in tendon. In addition to fibrillins, microfibrils may contain other associated proteins.


cardiac myofibril

A cardiac myofibril is a myofibril specific to cardiac muscle cells.


actin filament of cell cortex of cell tip

Any actin filament that is part of a cell cortex of cell tip.


complex of collagen trimers

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


paraflagellar rod

A large lattice-like axial structure found in some flagellated protists which extends alongside the axoneme. Protein components of the paraflagellar rod are likely implicated, among other, in adenine nucleotide signaling and metabolism, and in calcium signaling.


mastigoneme

A hair-like structure covering the flagella found in some algae (heterokonts and cryptophytes). It is approximately 15 nm in diameter, and usually consist of a tubular shaft that itself terminates in smaller hairs. It is composed of glycoproteins and, likely, carbohydrates. Mastigonemes may assist in locomotion by increasing the surface area of a flagellum.


C2 axonemal microtubule

One of two microtubules present in the axonemal central pair. It is distinguishable from the C1 axonemal microtubule (also called C1 tubule) by the presence of differing protein components of the projections.


collagen beaded filament

A supramolecular assembly of collagen trimers with a 'beads on a string'-like structure.


outer dense fiber

A supramolecular fiber found in the flagella of mammalian sperm that surrounds the nine microtubule doublets. These dense fibers are stiff and noncontractile. In human, they consist of about 10 major and at least 15 minor proteins, where all major proteins are ODF1, ODF2 or ODF2-related proteins.


supramolecular fiber

A polymer consisting of an indefinite number of protein or protein complex subunits that have polymerised to form a fiber-shaped structure.


horsetail-astral microtubule array

An array of astral microtubules that emanates from the spindle pole body during meiosis and facilitates horsetail nuclear movement.


intranuclear rod

A macromolecular fiber consisting of actin and cofilin that is formed in the nucleus as a consequence of chemical or mechanical stress conditions.


mitotic spindle microtubule

Any microtubule that is part of a mitotic spindle; anchored at one spindle pole.


mitotic spindle astral microtubule

Any of the mitotic spindle microtubules that radiate in all directions from the spindle poles and are thought to contribute to the forces that separate the poles and position them in relation to the rest of the cell.


banded collagen fibril

A supramolecular assembly of fibrillar collagen complexes in the form of a long fiber (fibril) with transverse striations (bands).


aster

An array of microtubules emanating from a spindle pole MTOC that do not connect to kinetochores.


neurofilament

A type of intermediate filament found in the core of neuronal axons. Neurofilaments are heteropolymers composed of three type IV polypeptides: NF-L, NF-M, and NF-H (for low, middle, and high molecular weight). Neurofilaments are responsible for the radial growth of an axon and determine axonal diameter.


glial filament

An intermediate filament composed of glial fibrillary acidic protein (GFAP) and found in astrocytes.


myofibril

The contractile element of skeletal and cardiac muscle; a long, highly organized bundle of actin, myosin, and other proteins that contracts by a sliding filament mechanism.


mitotic spindle kinetochore microtubule

Any of the mitotic spindle microtubules that attach to the kinetochores of chromosomes by their plus ends, and maneuver the chromosomes during mitotic chromosome segregation.


striated muscle myosin thick filament

Bipolar filaments formed of polymers of a muscle-specific myosin II isoform, found in the middle of sarcomeres in myofibrils.


axonemal microtubule

A microtubule in the axoneme of a eukaryotic cilium or flagellum; an axoneme contains nine modified doublet microtubules, which may or may not surround a pair of single microtubules.


B axonemal microtubule

An incomplete microtubule containing 10 protofilaments that fuses with a complete microtubule called A tubule (containing 13 protofilaments) to form an axonemal outer doublet.


cortical microtubule, transverse to long axis

Arrays of microtubules underlying and connected to the plasma membrane, in the cortical cytosol, oriented mainly with their axes transverse to the long axis of the cell (and root in plants). In plants it influences the direction of cellulose microfibril deposition.


C1 axonemal microtubule

One of two microtubules present in the axonemal central pair. It is distinguishable from the C2 axonemal microtubule (also called C2 tubule) by the presence of differing protein components of the projections.


nuclear microtubule

Any microtubule in the nucleus of a cell.


trichome papilla

A plant cell papilla that is part of a trichome cell.


investment cone

A cytoskeletal part that consists of a microfilament-rich cone that forms round each nucleus in a spermatogenic cyst and translocates the length of the cyst during sperm individualization.


chiasma

A connection formed between chromatids, visible during meiosis, thought to be the point of the interchange involved in crossing-over.


neuromuscular junction of skeletal muscle fiber

A neuromuscular junction in which the target muscle cell is a skeletal muscle fiber.


SCF-Hrt3/Pof7 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Hrt3 in S. cerevisiae (Pof7 in S. pombe).


yolk plasma

Discrete structures that partition the water-soluble portion of the yolk of oocytes and ova, which may or may not be membrane enclosed.


germ tube septin cap

A faint structure formed of septins found at the leading edge of growth in germ tubes of fungal cells growing filamentously. This cap of septins colocalizes with a region of the plasma membrane that is rich in ergosterol.


actin cytoskeleton of dendritic spine

The actin cytoskeleton that is part of a dendritic spine.


hyphae septin collar

A septin collar in pathogenic fungi involved in the constriction of hyphae at the plant plasmodesma enabling penetration of an adjacent cell.


prospore septin filament array

Arrays of septin filaments, or bars, found in a series of filamentous structures; observed in the prospore membrane during spore formation.


septin filament array

Arrays of septin filaments, or bars, found in a series of filamentous structures. Such structures have been observed in the prospore membrane during spore formation in S. cerevisiae and in the chlamydospore membrane during chlamydospore formation in C. albicans.


postsynaptic cytoskeleton

The portion of the cytoskeleton contained within the postsynapse.


postsynaptic septin cytoskeleton

The portion of the septin cytoskeleton contained within the postsynapse.


mating projection septin ring

A septin ring, i.e. a ring-shaped structure composed of septins and septin-associated proteins, located at the neck of a shmoo (mating projection). The septin ring in the neck of a shmoo may act as a barrier to localize mating factors in the shmoo tip.


postsynaptic intermediate filament cytoskeleton

The intermediate filament cytoskeleton that is part of a postsynapse.


septin ring

A tight ring-shaped structure that forms in the division plane at the site of cytokinesis; composed of members of the conserved family of filament-forming proteins called septins as well as septin-associated proteins. This type of septin structure is observed at the bud neck of budding fungal cells, at the site of cell division in animal cells, at the junction between the mother cell and a pseudohyphal projection, and also within hyphae of filamentous fungi at sites where a septum will form.


septin collar

A tubular, hourglass-shaped structure composed of highly ordered arrays of septin filaments; in budding yeast cells, the septin collar forms from the initial septin ring by expanding into the daughter cell.


postsynaptic actin cytoskeleton

The actin cytoskeleton that is part of a postsynapse.


germ tube septin ring

A tight ring-shaped structure that forms in the division plane within the germ tube of filamentous fungi at sites where a septum will form; composed of septins as well as septin-associated proteins.


split septin rings

A pair of rings that flank the site of cell division, formed by splitting of the septin ring (or collar) prior to cytokinesis; this double ring structure is thought to trap proteins needed for cytokinesis or the formation of the new membrane or cell wall between the two septin rings. Split septin rings are known to occur in budding yeast cells and probably occur in other cell types as well.


septin cytoskeleton

The part of the cytoskeleton (the internal framework of a cell) composed of septins and associated proteins. Includes septin cytoskeleton-associated complexes.


presynaptic actin cytoskeleton

The actin cytoskeleton that is part of a presynapse.


prospore septin ring

A tight ring-shaped structure that forms in the division plane at the site of cytokinesis in a prospore; composed of septins as well as septin-associated proteins.


chlamydospore septin filament array

Arrays of septin filaments, or bars, found in a series of filamentous structures. Observed in the chlamydospore membrane during chlamydospore formation.


neurofilament cytoskeleton

Intermediate filament cytoskeletal structure that is made up of neurofilaments. Neurofilaments are specialized intermediate filaments found in neurons.


hyphal septin cap

A faint structure formed of septins found at the leading edge of growth in hyphae of fungal cells growing filamentously. This cap of septins colocalizes with a region of the plasma membrane that is rich in ergosterol.


septin cap

A faint structure formed of septins found at the leading edge of growth in germ tubes and hyphae in fungal cells growing filamentously. This cap of septins colocalizes with a region of the plasma membrane that is rich in ergosterol.


pseudohyphal septin ring

A tight ring-shaped structure that forms in the division plane at the junction between the mother cell and a pseudohyphal projection; composed of septins as well as septin-associated proteins.


presynaptic cytoskeleton

The portion of the cytoskeleton contained within the presynapse.


microtubule cytoskeleton

The part of the cytoskeleton (the internal framework of a cell) composed of microtubules and associated proteins.


cellular bud neck septin ring

A ring-shaped structure that forms at the site of cytokinesis in the bud neck of a budding cell; composed of members of the conserved family of filament forming proteins called septins as well as septin-associated proteins. In S. cerevisiae, this structure forms at the time of bud emergence and the septins show a high rate of exchange.


perinuclear theca

A condensed cytoplasmic structure that covers the nucleus of mammalian spermatozoa except for a narrow zone around the insertion of the tail. It shows two distinct regions, a subacrosomal layer and, continuing caudally beyond the acrosomic system, the postacrosomal sheath. The perinuclear theca has been considered a cytoskeletal scaffold responsible for maintaining the overall architecture of the mature sperm head; however, recent studies indicate that the bulk of its constituent proteins are not traditional cytoskeletal proteins but rather a variety of cytosolic proteins.


presynaptic intermediate filament cytoskeleton

The intermediate filament cytoskeleton that is part of a presynapse.


cytoskeleton of dendritic spine

The portion of the cytoskeleton that lies within a dendritic spine. The actin component of this cytoskeleton is involved in spine head remodeling in response to postsynaptic signaling.


intermediate filament cytoskeleton

Cytoskeletal structure made from intermediate filaments, typically organized in the cytosol as an extended system that stretches from the nuclear envelope to the plasma membrane. Some intermediate filaments run parallel to the cell surface, while others traverse the cytosol; together they form an internal framework that helps support the shape and resilience of the cell.


hyphal septin ring

A tight ring-shaped structure that forms in the division plane within hyphae of filamentous fungi at sites where a septum will form; composed of septins as well as septin-associated proteins.


cellular bud neck split septin rings

Two separate septin rings that are formed from the septin collar at the time of cytokinesis in cells that divide by budding. These two rings are thought to delineate a special compartment in which factors involved in cytokinesis are concentrated.


spectrin-associated cytoskeleton

The part of the cytoskeleton composed of spectrin, protein 4.1 and ankyrin. Spectrin-associated cytoskeleton is associated with the plasma membrane.


medial cortex septin ring

A ring-shaped structure that forms at the medial cortex of a symmetrically dividing cell at the onset of cytokinesis; composed of members of the conserved family of filament forming proteins called septins as well as septin-associated proteins.


The portion of the spectrin-associated cytoskeleton contained within the postsynapse.


MsbA transporter complex

An ATP-binding cassette (ABC) transporter complex made up of a dimer of MsbA. Facilitates the export across the plasma membrane of, amongst others, lipid A and lipopolysaccharide. In contrast to most ABC transporter complexes, each chain of the homodimer contains both the transmembrane domain (TMD) and the cytoplasmic ATP-binding domain (NBD).


mitochondrial prohibitin complex

A complex composed of two proteins, prohibitin 1 and prohibitin 2 (PHB1/PHB-1 and PHB2/PHB-2) that is highly conserved amongst eukaryotes and associated with the inner mitochondrial membrane. The mitochondrial prohibitin complex is a macromolecular supercomplex composed of repeating heterodimeric subunits of PHB1 and PHB2. The mitochondrial prohibitin complex plays a role in a number of biological processes, including mitochondrial biogenesis and function, development, replicative senescence, and cell death.


dinoflagellate apical horn

A horn-shaped dinoflagellate apex found in thecate species.


host cell endocytic vesicle membrane

The lipid bilayer surrounding a host cell endocytic vesicle.


esterosome membrane

The lipid bilayer surrounding an esterosome. This membrane has characteristics of rough endoplasmic reticulum (RER) membranes.


BID-BCL-xl complex

A heterodimeric protein complex consisting of BID and BCL-xl, members of the Bcl-2 family of anti- and proapoptotic regulators.


Golgi medial cisterna

The middle Golgi cisterna (or cisternae).


oligosaccharyltransferase I complex

An oligosaccharyltransferase (OST) complex that contains at least seven polypeptides and is the major OST complex in mammalian cells. Of the three forms of mammalian OST complex identified, the OSTI complex has the weakest affinity for ribosomes.


glycolate oxidase complex

An enzyme complex that catalyzes the oxidation of 2-hydroxy acid to form 2-oxo acid and hydrogen peroxide (H2O2). The enzyme is a flavoprotein (FMN).


thioredoxin-disulfide reductase complex

A protein complex which is capable of thioredoxin-disulfide reductase activity.


connexin complex

An assembly of six molecules of connexin, made in the Golgi apparatus and subsequently transported to the plasma membrane, where docking of two connexons on apposed plasma membranes across the extracellular space forms a gap junction.


stress fiber

A contractile actin filament bundle that consists of short actin filaments with alternating polarity, cross-linked by alpha-actinin and possibly other actin bundling proteins, and with myosin present in a periodic distribution along the fiber.


MHC class Ib protein complex

A transmembrane protein complex composed of a MHC class Ib alpha chain and, in most cases, an invariant beta2-microglobin chain, and with or without a bound peptide or lipid antigen. Class Ib here refers to non-classical class I molecules, such as those of the CD1 or HLA-E gene families.


chromoplast inner membrane

The inner, i.e. lumen-facing, lipid bilayer of the chromoplast envelope; also faces the chromoplast stroma.


chromoplast membrane

Either of the lipid bilayers that surround a chromoplast and form the chromoplast envelope.


H zone

A relatively pale zone traversing the center of the A band of a sarcomere, visible in relaxed muscle fibers; consists of the central portion of thick (myosin) filaments that are not overlapped by thin (actin) filaments.


rixosome complex

A conserved RNA endonuclease complex required for spreading and epigenetic inheritance of heterochromatin. The rixosome contains six unique subunits: three structural subunits (Crb3, Rix1, and Ipi1) which form the core of the complex, and three catalytic subunits (the endonuclease Las1, the polynucleotide kinase Grc3, and the AAA-type ATPase Mdn1), which are involved in the processing of ribosomal RNA precursors. All subunits are essential for viability and are conserved from yeast to mammals, including humans.


t-UTP complex

A protein complex that forms a subcomplex of the 90S preribosome and is required for the subsequent assembly of the rest of the preribosome. In S. cerevisiae, it is composed of Utp5p, Utp4p, Nan1p, Utp8p, Utp9p, Utp10 and Utp15p.


collagen type IX trimer

A collagen heterotrimer containing type IX alpha chains in alpha1(IX)alpha2(IX)alpha3(IX) trimers; type IX collagen triple helices associate to form a structure that links glycosaminoglycans to type II collagen fibrils.


amyloplast

A plastid whose main function is to synthesize and store starch.


secondary cell wall

A plant cell wall that is no longer able to expand and so does not permit growth. Secondary cell walls contain less pectin that primary cell walls. The secondary cell is mostly composed of cellulose and is strengthened with lignin.


extrinsic component of periplasmic side of plasma membrane

The component of a plasma membrane consisting of gene products and protein complexes that are loosely bound to its periplasmic surface, but not integrated into the hydrophobic region.


hippocampal mossy fiber to CA3 synapse

One of the giant synapses that form between the mossy fiber axons of dentate gyrus granule cells and the large complex spines of CA3 pyramidal cells. It consists of a giant bouton known as the mossy fiber expansion, synapsed to the complex, multiheaded spine (thorny excresence) of a CA3 pyramidal cell.


left caudal basal body

Any ciliary basal body that is part of a left caudal flagellum found in Giardia species (trophozoite stage).


spindle pole centrosome

A centrosome from which one pole of a mitotic or meiotic spindle is organized.


CHOP-ATF4 complex

A heterodimeric transcription factor complex that is composed of CHOP (C/EBP homology protein, GADD153) and ATF4 (activating transcription factor 4, also known as cAMP response element binding protein-2/CREB-2) subunits.


G-protein beta/gamma-subunit complex

The heterodimer formed by the beta and gamma subunits of a heterotrimeric G protein, which dissociates from the alpha subunit upon guanine nuclotide exchange.


viral capsid, minor subunit

The part of the viral capsid that comprises the less common capsomere type. For example, in a T=3 icosahedral capsid, which is composed of 12 pentameric and 20 hexameric capsomeres, the pentameric capsomeres are minor subunits.


viral capsid, major subunit

The part of the viral capsid that comprises the most common capsomere type. For example, in a T=3 icosahedral capsid, which is composed of 12 pentameric and 20 hexameric capsomeres, the hexameric capsomeres are major subunits.


sexual spore wall

A specialized envelope lying outside the cell membrane of a spore derived from a product of meiosis.


spore wall

The specialized envelope lying outside the cell membrane of a spore.


asexual spore wall

A specialized envelope lying outside the cell membrane of a spore derived from an asexual process. Examples of this process are found in bacterial and fungal species.


ascospore wall

The specialized cell wall of the ascospore (spore), which is the product of meiotic division. Examples of this component are found in Fungi.


endospore external encapsulating structure

The structures that lie outside the inner membrane and surround the entire endospore; consists of a peptidoglycan-containing inner layer (the endospore cortex) surrounded by a multilayered proteinaceous coat. An exosporium may be present as an extreme outer layer.


MBF transcription complex

A protein complex that binds to the Mlu1 cell cycle box (MCB) promoter element, consensus sequence ACGCGN, and is involved in regulation of transcription during the G1/S transition of the cell cycle. In Saccharomyces, the complex contains a heterodimer of the DNA binding protein Mbp1p and the activator Swi6p, and is associated with additional proteins known as Nrm1p, Msa1p, and Msa2p; in Schizosaccharomyces the complex contains Res1p, Res2p, and Cdc10p.


cellular bud

A protuberance from a cell of an organism that reproduces by budding, which will grow larger and become a separate daughter cell after nuclear division, cytokinesis, and cell wall formation (when appropriate). The daughter cell may completely separate from the mother cell, or the mother and daughter cells may remain associated.


NarGHI complex

A heterotrimeric protein complex with iron-sulfur and molybdenum cofactors that functions as a terminal reductase in electron transport pathways that operate during anaerobic nitrate respiration. In E. coli electrons are passed from the FdnGHI complex to the NarGHI complex via menoquinone and menaquinol. Within NarGHI, electrons are passed from the two heme molecules in the NarI subunit down a Fe-S cluster chain in the NarH and NarG subunits to the Molybdenum cofactor, Mo-bisMGD, in the NarG subunit.


mitotic spindle assembly checkpoint MAD1-MAD2 complex

A protein complex involved in the assembly of the mitotic checkpoint complex that in turn inhibits the anaphase promoting complex/cyclosome (APC/C). The MAD1 dimer recruits the open form of MAD2 (O-MAD2) turning it into the closed form (C-MAD2) upon binding. C-MAD2 inhibits CDC20, a member of the APC/C, upon release from the MAD1-MAD2 complex.


trans-Golgi network

The network of interconnected tubular and cisternal structures located within the Golgi apparatus on the side distal to the endoplasmic reticulum, from which secretory vesicles emerge. The trans-Golgi network is important in the later stages of protein secretion where it is thought to play a key role in the sorting and targeting of secreted proteins to the correct destination.


Noc1p-Noc2p complex

A heterodimer associated with 90S and 66S preribosomes. Predominantly, but not exclusively, nucleolar; involved in ribosomal large subunit biogenesis.


A protein complex that is formed by the association of a heterodimeric interleukin-12 receptor complex with an interleukin-12 heterodimer.


thylakoid membrane

The pigmented membrane of any thylakoid.


photosynthetic membrane

A membrane enriched in complexes formed of reaction centers, accessory pigments and electron carriers, in which photosynthetic reactions take place.


cyanelle thylakoid membrane

The lipid bilayer membrane of any thylakoid within a cyanelle.


prothylakoid membrane

The membrane of prothylakoids, underdeveloped thylakoids found in etioplasts, lacking competent photosynthetic membranes.


plasma membrane-derived chromatophore membrane

The lipid bilayer associated with a plasma membrane-derived chromatophore; surrounds chromatophores that form complete vesicles.


plasma membrane-derived thylakoid membrane

The pigmented membrane of a plasma membrane-derived thylakoid.


organellar chromatophore thylakoid membrane

The lipid bilayer membrane of any thylakoid within an organellar chromatophore.


plastid thylakoid membrane

The lipid bilayer membrane of any thylakoid within a plastid.


infected host cell surface knob

Protrusion that develops in the plasma membrane of a parasitized erythrocyte. An example of this component is found in Plasmodium species.


microvillar actin bundle

A parallel bundle of actin filaments at the core of a microvillus.


parallel actin filament bundle

An actin filament bundle in which the filaments are tightly packed (approximately 10-20 nm apart) and oriented with the same polarity.


formin-nucleated actin cable

An actin filament bundle that consists of short filaments organized into bundles of uniform polarity, and is nucleated by formins. In fungal cells, myosin motors transport cargo along actin cables toward sites of polarized cell growth; actin cables may play a similar role in pollen tube growth.


actin filament bundle of filopodium

A parallel bundle of actin filaments that is part of filopodium. Filaments are oriented such that the plus (barbed) ends are at the tip of the protrusion, capped by a tip complex.


actin filament bundle of stereocilium

A bundle of hundreds of cross-linked actin filaments (an actin cable), that is the supporting structure of a stereocilium. Filaments are oriented such that the the plus (barbed) ends are at the tip of the protrusion and are capped by a tip complex which bridges to the plasma membrane.


actin filament bundle of actin-based cell projection

A bundle of cross-linked actin filaments that is part of an actin-based cell protrusion, in which filaments are oriented such that the plus (barbed) ends are at the tip of the protrusion, capped by a tip complex which stabilizes the filaments.


ficolin-1-rich granule membrane

The lipid bilayer surrounding a ficolin-1-rich granule.


cytoplasmic vesicle membrane

The lipid bilayer surrounding a cytoplasmic vesicle.


clathrin-coated phagocytic vesicle membrane

The lipid bilayer surrounding a clathrin-coated phagocytic vesicle.


endosome membrane

The lipid bilayer surrounding an endosome.


early endosome membrane

The lipid bilayer surrounding an early endosome.


inter-Golgi transport vesicle membrane

The lipid bilayer surrounding a vesicle transporting substances within the Golgi.


coated vesicle membrane

The lipid bilayer surrounding a coated vesicle.


outer acrosomal membrane

The acrosomal membrane region that underlies the plasma membrane of the sperm. This membrane fuses with the sperm plasma membrane as part of the acrosome reaction.


chromaffin granule membrane

The lipid bilayer surrounding a chromaffin granule, a 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.


clathrin-coated endocytic vesicle membrane

The lipid bilayer surrounding a clathrin-coated endocytic vesicle.


transport vesicle membrane

The lipid bilayer surrounding a transport vesicle.


Golgi-associated vesicle membrane

The lipid bilayer surrounding a vesicle associated with the Golgi apparatus.


specific granule membrane

The lipid bilayer surrounding a specific granule, a 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.


postsynaptic early endosome membrane

The lipid bilayer surrounding a postsynaptic early endosome.


organellar chromatophore inner membrane

The inner, i.e. lumen-facing, of the two lipid bilayers surrounding an organellar chromatophore.


secretory granule membrane

The lipid bilayer surrounding a secretory granule.


postsynaptic endosome membrane

The lipid bilayer surrounding a postsynaptic endosome.


phagolysosome vesicle membrane

The lipid bylayer surrounding a phagolysosome.


macropinosome membrane

The lipid bilayer surrounding a macropinosome.


lamellar body membrane

The lipid bilayer surrounding a lamellar body. A lamellar body is 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.


platelet dense granule membrane

The lipid bilayer surrounding the platelet dense granule.


organellar chromatophore membrane

Either of the lipid bilayers that surround an organellar chromatophore.


presynaptic endosome membrane

The lipid bilayer surrounding a presynaptic endosome.


postsynaptic recycling endosome membrane

The lipid bilayer surrounding a postsynaptic recycling endosome.


azurophil granule membrane

The lipid bilayer surrounding an azurophil granule, a primary lysosomal granule found in neutrophil granulocytes that contains a wide range of hydrolytic enzymes and is released into the extracellular fluid.


recycling endosome membrane

The lipid bilayer surrounding a recycling endosome.


trans-Golgi network transport vesicle membrane

The lipid bilayer surrounding a vesicle transporting substances between the trans-Golgi network and other parts of the cell.


synaptic vesicle membrane

The lipid bilayer surrounding a synaptic vesicle.


platelet alpha granule membrane

The lipid bilayer surrounding the platelet alpha granule.


dense core granule membrane

The lipid bilayer surrounding a dense core granule.


endocytic vesicle membrane

The lipid bilayer surrounding an endocytic vesicle.


peribacteroid membrane

A membrane that surrounds one or more bacteroids (such as nitrogen-fixing bacteroids within legume root nodule cells).


COPI-coated vesicle membrane

The lipid bilayer surrounding a COPI-coated vesicle.


alveolar lamellar body membrane

The lipid bilayer surrounding an alveolar lamellar body, a specialized secretory organelle found in type II pneumocytes and involved in the synthesis, secretion, and reutilization of pulmonary surfactant.


early phagosome membrane

The lipid bilayer surrounding an early phagosome.


tertiary granule membrane

The lipid bilayer surrounding a tertiary granule.


endolysosome membrane

The lipid bilayer surrounding an endolysosome. An endolysosome is a transient hybrid organelle formed by fusion of a late endosome with a lysosome.


aleurone grain membrane

The lipid bilayer surrounding an aleurone grain.


epidermal lamellar body membrane

The lipid bilayer surrounding an 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.


gut granule membrane

The membrane of a gut granule, a lysosome-related organelle contained within the intestinal cells of the nematode C. elegans.


multivesicular body membrane

The lipid bilayer surrounding a multivesicular body.


clathrin-sculpted monoamine transport vesicle membrane

The lipid bilayer surrounding a clathrin-sculpted monoamine transport vesicle.


merozoite dense granule membrane

The lipid bilayer surrounding a dense granule of the type found in apicomplexan parasites.


inner acrosomal membrane

The acrosomal membrane region that underlies the acrosomal vesicle and is located toward the sperm nucleus. This region is responsible for molecular interactions allowing the sperm to penetrate the zona pellucida and fuses with the egg plasma membrane.


late endosome membrane

The lipid bilayer surrounding a late endosome.


clathrin-sculpted glutamate transport vesicle membrane

The lipid bilayer surrounding a clathrin-sculpted glutamate transport vesicle.


multivesicular body, internal vesicle membrane

The lipid bilayer surrounding a multivesicular body internal vesicle.


organellar chromatophore outer membrane

The outer, i.e. cytoplasm-facing, of the two lipid bilayers surrounding an organellar chromatophore.


Golgi to ER transport vesicle membrane

The lipid bilayer surrounding a vesicle transporting substances from the Golgi to the ER.


phagolysosome membrane

The lipid bilayer surrounding a phagolysosome.


exocytic vesicle membrane

The lipid bilayer surrounding an exocytic vesicle.


clathrin-sculpted gamma-aminobutyric acid transport vesicle membrane

The lipid bilayer surrounding a clathrin-sculpted gamma-aminobutyric acid transport vesicle.


acrosomal membrane

The membrane that surrounds the acrosomal lumen. The acrosome is a special type of lysosome 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.


rod photoreceptor disc membrane

Stack of disc membranes located inside a rod photoreceptor outer segment, and containing densely packed molecules of rhodopsin photoreceptor proteins that traverse the lipid bilayer. It is thought that rod disc membranes arise as evaginations of the ciliary membrane near the base of the outer segment, which then become completely separated from the ciliary membrane, during the development of the rod outer segment.


Cvt vesicle membrane

Either of the two lipid bilayers surrounding a Cvt vesicle, a vesicle that functions in the cytoplasm-to-vacuole targeting (Cvt) pathway.


phagocytic vesicle membrane

The lipid bilayer surrounding a phagocytic vesicle.


chitosome membrane

The lipid bilayer surrounding a chitosome.


clathrin-coated vesicle membrane

The lipid bilayer surrounding a clathrin-coated vesicle.


foot layer

The inner layer of the ectexine.


protein C inhibitor-KLK3 complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and prostate-specific antigen (KLK3); formation of the complex inhibits the serine protease activity of prostate-specific antigen.


peptidase inhibitor complex

A protein complex which is capable of peptidase inhibitor 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.


protein C inhibitor-coagulation factor V complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and coagulation factor V (F5); formation of the complex inhibits the serine protease activity of coagulation factor V.


protein C inhibitor-thrombin complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and thrombin (F2); formation of the complex inhibits the serine protease activity of thrombin.


protease inhibitor complex

A heterodimeric protein complex that contains a protease inhibitor and a protease; formation of the complex inhibits protease activity.


protein C inhibitor-coagulation factor XI complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and coagulation factor XI (F11); formation of the complex inhibits the serine protease activity of coagulation factor XI.


protein C inhibitor-acrosin complex

A heterodimeric protein complex of protein C inhibitor (SERPINA5) and acrosin; formation of the complex inhibits the protease activity of acrosin.


serine protease inhibitor complex

A heterodimeric protein complex that contains a serine protease inhibitor and a protease; formation of the complex inhibits serine protease activity.


protein C inhibitor-coagulation factor Xa complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and coagulation factor Xa (F10); formation of the complex inhibits the serine protease activity of coagulation factor Xa.


protein C inhibitor-TMPRSS11E complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and transmembrane protease serine 11E (TMPRSS11E); formation of the complex inhibits the serine protease activity of transmembrane protease serine 11E.


protein C inhibitor-TMPRSS7 complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and transmembrane protease serine 7 (TMPRSS7); formation of the complex inhibits the serine protease activity of transmembrane protease serine 7.


germ plasm

Differentiated cytoplasm associated with a pole of an oocyte, egg or early embryo that will be inherited by the cells that will give rise to the germ line.


cytoplasmic periphery of the nuclear pore complex

Cytoplasm situated in close proximity to a nuclear pore complex.


alphaV-beta3 integrin-NOV complex

A protein complex that consists of an alphaV-beta3 integrin complex bound to the extracellular matrix protein NOV.


integrin alphaL-beta2 complex

An integrin complex that comprises one alphaL subunit and one beta2 subunit.


tRNA-splicing ligase complex

A protein complex that catalyzes the ligation of cleaved pre-tRNAs by directly joining spliced tRNA halves to mature-sized tRNAs by incorporating the precursor-derived splice junction phosphate into the mature tRNA as a canonical 3',5'-phosphodiester.


MMXD complex

A protein complex that contains the proteins MMS19, MIP18 and XPD, localizes to mitotic spindle during mitosis, and is required for proper chromosome segregation.


peptidase complex

A protein complex which is capable of peptidase activity.


spermatoproteasome complex

A proteasome specifically found in mammalian testis. Contains the proteasome activator PA200 in the regulatory particle, and beta1i, beta2i, beta5i and/or alpha4s in the core (20S) subunit. Beta1i, beta2i and beta5i are inducible catalytic subunits, closely related to beta1, beta2 and beta5. Alpha4s is a sperm-specific 20S subunit, but unlike other alternative 20S subunits alpha4s lies in the outer alpha-ring and lacks catalytic activity.


endopeptidase complex

A protein complex which is capable of endopeptidase activity.


caspase complex

A protein complex that contains one or more cysteine-type endopeptidases (also called caspases), which give the complex a peptidase activity with specificity for the hydrolysis of aspartyl bonds. These complexes may be involved e.g. in apoptotic or inflammation processes.


serine-type peptidase complex

A protein complex which is capable of serine-type peptidase activity.


HslUV protease complex

A protein complex that possesses ATP-dependent protease activity; consists of an ATPase large subunit with homology to other ClpX family ATPases and a peptidase small subunit related to the proteasomal beta-subunits of eukaryotes. In the E. coli complex, a double ring-shaped homohexamer of HslV is capped on each side by a ring-shaped HslU homohexamer.


nuclear proteasome complex

A proteasome found in the nucleus of a cell.


GPI-anchor transamidase complex

An enzyme complex which in humans and yeast consists of at least five proteins; for example, the complex contains GAA1, GPI8, PIG-S, PIG-U, and PIG-T in human, and Gaa1p, Gab1p, Gpi8p, Gpi16p, and Gpi17p in yeast. Catalyzes the posttranslational attachment of the carboxy-terminus of a precursor protein to a GPI-anchor.


PNGase complex

A protein complex responsible for the catalysis of the reaction: 4-N-(N-acetyl-D-glucosaminyl)-protein + H2O = N-acetyl-beta-D-glucosaminylamine + peptide L-aspartate. This reaction is the hydrolysis of an N4-(acetyl-beta-D-glucosaminyl)asparagine residue in which the N-acetyl-D-glucosamine residue may be further glycosylated, to yield a (substituted) N-acetyl-beta-D-glucosaminylamine and the peptide containing an aspartic residue.


m-AAA complex

Protease complex of the mitochondrial inner membrane that is involved in mitochondrial protein turnover and in processing of proteins imported into mitochondria.


separase-securin complex

A protein complex that includes separase (a protease which cleaves cohesin as part of chromosome separation) and securin, a protease inhibitor. Chromosome separation is inhibited until securin is degraded by the Anaphase Promoting Complex (APC).


SAGA complex

A SAGA-type histone acetyltransferase complex that deubiquitinates H2A and/or H2B. This complex is organized into several functional submodules: a structural core including the activator binding module and consisting of ADA1 or a homolog, members of the SPT and TAF protein families as well as promotor recruitment factor TRRAP/TRA1, a histone acetyltransferase (HAT) module consisting of GCN5/KAT2A or PCAF/KAT2B, ADA2, ADA3/NGG1, and SGF29 or homologues thereof, a histone deubiquitinase (DUB) module consisting of ATXN7/SGF73, ATXN7L3/SGF11, ENY2/SUS1 and USP22/UBP8 or homologues thereof, and in some taxa a splicing module consisting of SF3B3 and SF3B5 or homologues thereof (not in fungi). In budding yeast also contains Spt8 which distinguishes it from SAGA-like (SLIK) complex (GO:0046695).


signal peptidase complex

A protein complex that is located in the endoplasmic reticulum membrane and cleaves the signal sequence from precursor proteins following their transport out of the cytoplasmic space.


cytosolic proteasome complex

A proteasome complex found in the cytosol of a cell.


H-gal-GP complex

A membrane glycoprotein complex with aspartyl proteinase and metalloproteinase activity which is expressed in the gut. An example of this is found in the nematode Haemonchus contortus.


calpain complex

A calcium-dependent protease complex that processes its substrate by limited proteolysis rather than degrading it. In some cases limited proteolysis is required for the activation of its substrate.


serine-type endopeptidase complex

A protein complex which is capable of serine-type endopeptidase activity.


cerebellar Golgi cell to granule cell synapse

A synapse formed by a cerebellar Golgi cell synapsing on to a cerebellar granule cell.


presynaptic periactive zone

A region that surrounds the active zone of the presynaptic plasma membrane, and is specialized for the control of synaptic development.


multiple synapse bouton, contacting single dendrite

A single axon terminal bouton making contact onto two or more dendritic spines protruding from the same dendrite.


tripartite attachment complex

A three-part cytoskeletal structure in kinetoplastid species linking mitochondrial DNA organised in a kinetoplast through the mitochondrial membranes to the basal body.


dense body

An electron dense body which may contain granules.


viral capsid, internal space

The region of a virus contained within the capsid shell, and usually containing the viral genome and accessory proteins.


nitrite reductase complex [NAD(P)H]

Complex that possesses nitrite reductase [NAD(P)H] activity.


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.


CST complex

A complex formed by the association of Cdc13 (CTC1 in mammals) with Stn1 in yeast (OBFC1 in mammals) and Ten1 protein (also TEN1 in mammals) with single-stranded telomeric DNA. The CST complex plays a role in telomere protection.


primary endosperm nucleus

Nucleus resulting from the fusion of the male gamete and two polar nuclei in the central cell of the embryo sac.


matrilin complex

A cartilage extracellular matrix complex that mediates interactions between major components of the extracellular matrix such as collagens and proteoglycans and contributes to their fibrillar network. Exists as an obligate homotrimer.


alphaV-beta3 integrin-LPP3 complex

A protein complex that consists of an alphaV-beta3 integrin complex bound to lipid phosphate phosphohydrolase-3.


actin cortical patch

An endocytic patch that consists of an actin-containing structure found at the plasma membrane in cells; formed of networks of branched actin filaments that lie just beneath the plasma membrane and assemble, move, and disassemble rapidly. An example of this is the actin cortical patch found in Saccharomyces cerevisiae.


endocytic patch

The part of the cell cortex consisting of an aggregation of proteins that will give rise to an endocytic vesicle.


sodium channel complex

An ion channel complex through which sodium ions pass.


cation channel complex

An ion channel complex through which cations pass.


intracellular cyclic nucleotide activated cation channel complex

A protein complex that forms a transmembrane channel through which cations ions may pass in response to an intracellular cyclic nucleotide binding to the channel complex or one of its constituent parts.


uniplex complex

A calcium channel complex in the mitochondrial inner membrane capable of highly-selective calcium channel activity. Its components include the EF-hand-containing proteins mitochondrial calcium uptake 1 (MICU1) and MICU2, the pore-forming subunit mitochondrial calcium uniporter (MCU) and its paralog MCUb, and the MCU regulator EMRE.


HCN channel complex

A cation ion channel with a preference for K+ over Na+ ions, which is activated by membrane hyperpolarization, and consists of a tetramer of HCN family members. Some members of this family (HCN1, HCN2 and HCN4) are also activated when cAMP binds to their cyclic nucleotide binding domain (CNBD). Channel complexes of this family play an important role in the control of pacemaker activity in the heart.


Kv4.2-KChIP1 channel complex

A voltage-gated potassium channel complex that contains the Kv channel interacting protein KChIP1 associated with the channel via interaction with the Kv alpha subunit 4.2.


Kir2 inward rectifier potassium channel complex

A inward rectifier potassium channel complex. Homo- or heterotetramer composed of subunits of the eukaryotic Kir2 protein family. Plays a key role in maintaining the correct resting potential in eukaryotic cells.


inward rectifying potassium channel

A protein complex that comprises four pore-forming (Kir6.x) and four regulatory sulphonylurea receptor (SURx) subunits and forms a transmembrane channel through which ions may pass. The opening and closing of the channel is regulated by ATP: binding of ATP to the Kir6.x subunit inhibits channel activity, whereas binding of Mg2+-complexed ATP or ADP to the SURx subunit stimulates channel activity.


Kv4.2-KChIP3 channel complex

A voltage-gated potassium channel complex that contains the Kv channel interacting protein KChIP3 associated with the channel via interaction with the Kv alpha subunit 4.2.


mitochondrial ATP-gated potassium channel complex

A protein-containing complex that is capable of the ATP-dependent diffusion of a potassium ion across the mitochondrial inner membrane.


voltage-gated sodium channel complex

A sodium channel in a cell membrane whose opening is governed by the membrane potential.


ryanodine receptor complex

A voltage-gated calcium-release channel complex of the sarcoplasmic or endoplasmic reticulum. It plays an important role in the excitation-contraction (E-C) coupling of muscle cells. RyR comprises a family of ryanodine receptors, widely expressed throughout the animal kingdom.


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.


potassium channel complex

An ion channel complex through which potassium ions pass.


serotonin-activated cation-selective channel complex

A protein complex which is capable of serotonin-activated cation-selective channel activity. Mainly found in pre- and postsynaptic membranes of the brain and gastrointestinal tract. Depending on its location it transports Ca2+, Mg2+, Na+ or K+. It is always a pentamer, containing at least the 5HT3A subunit forming 5HT3A homopentamers or 5HT3A/B heteropentamers. In human, 5HT3A/C, A/D and A/E heteropentamers also exist.


inward rectifier potassium channel complex

A protein complex which is capable of inward rectifier potassium channel activity.


Kv4.2-KChIP2 channel complex

A voltage-gated potassium channel complex that contains the Kv channel interacting protein KChIP2 associated with the channel via interaction with the Kv alpha subunit 4.2.


kainate selective glutamate receptor complex

An assembly of four or five subunits which form a structure with an extracellular N-terminus and a large loop that together form the ligand binding domain. The C-terminus is intracellular. The ionotropic glutamate receptor complex itself acts as a ligand gated ion channel; on binding glutamate, charged ions pass through a channel in the center of the receptor complex. Kainate receptors are multimeric assemblies of GluK1-3 (also called GluR5-7), GluK4 (KA1) and GluK5 (KA2) subunits.


Kv4.3-DPP10 channel complex

A voltage-gated potassium channel complex that contains the peptidase-related protein DPP10 associated with the channel via interaction with the Kv alpha subunit 4.3.


I(KACh) inward rectifier potassium channel complex

An inward rectifier potassium channel complex expressed in cardiac muscle, specifically the sinoatrial node and atria, where it controls the heart rate, via regulation by G protein-coupled receptor signaling. In mammals it is composed of GIRK1 (or Kir3.1) and GIRK4 (or Kir3.4) subunits.


Kv4.1-DPP10 channel complex

A voltage-gated potassium channel complex that contains the peptidase-related protein DPP10 associated with the channel via interaction with the Kv alpha subunit 4.1.


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.


calcium channel complex

An ion channel complex through which calcium ions pass.


Kv4.2-Kv4.3 channel complex

A voltage-gated potassium channel complex that contains the Kv alpha subunits 4.2 and 4.3.


CatSper complex

A sperm-specific voltage-gated calcium channel that controls the intracellular calcium ion concentration and, thereby, the swimming behavior of sperm. Consists of a heteromeric tetramer surrounding a calcium ion- selective pore. May also contain additional auxiliary subunits.


Kv4.2-KChIP4 channel complex

A voltage-gated potassium channel complex that contains the Kv channel interacting protein KChIP4 associated with the channel via interaction with the Kv alpha subunit 4.2.


light-activated voltage-gated calcium channel complex

A protein complex that forms a transmembrane channel through which calcium ions may cross a cell membrane in response to changes in membrane potential generated in response to a light stimulus.


Kv4.2-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 4.2.


Kv4.1-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 4.1.


A SNARE complex that contains cellubrevin (VAMP3), VAMP4, endobrevin (VAMP8), and syntaxin 6 (or orthologs thereof).


macromolecule

A macromolecule is a molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass.


polypeptide

A peptide containing ten or more amino acid residues.


biomacromolecule

A macromolecule formed by a living organism.


flagella connector

A mobile transmembrane junction at the tip of the flagellum of some kinetoplastid species linking the tip of a new growing flagellum to an older flagellum.


TRAPPI protein complex

A complex that tethers COPII vesicles at ER-Golgi intermediate compartment. Its role in this part of the vesicular transport may start at the ER exit sites. Binds to a component of the COPII coat. In yeast it includes the following subunits: Bet3 (as homodimer), Bet5, Trs20, Trs23, Trs31, Trs33 which are regarded as the core subunits of all TRAPP complexes in yeast.


BIM-BCL-2 complex

A heterodimeric protein complex consisting of BIM and BCL-2, members of the Bcl-2 family of anti- and proapoptotic regulators.


3-methylcrotonyl-CoA carboxylase complex, mitochondrial

A mitochondrial protein complex which is capable of 3-methylcrotonyl-CoA carboxylase activity. In mammals, at least, consists as a dodecamer of 6 alpha and 6 beta subunits. MCCC-alpha has a covalently bound biotin essential for the ATP-dependent carboxylation. MCCC-beta possesses carboxyltransferase activity which presumably is essential for binding to 3-methylcrotonyl-CoA.


cytosolic creatine kinase complex

A dimeric protein complex having creatine kinase activity.


cellulose microfibril

A microfibril composed of cellulose arranged in orthogonal layers. Cellulose is a straight chain polysaccharide composed of B(14) linked glucose subunits. It is a major component of plant cell walls. Higher plant microfibrils are about 10nm in diameter and extremely long in relation to their width. The cellulose molecules are oriented parallel to the long axis of the microfibril in a paracrystalline array, which provides great tensile strength. The microfibrils are held in place by the wall matrix and their orientation is closely controlled by the cell.


integrin alpha6-beta4 complex

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


neck portion of tanycyte

Elongated portion of a tanycyte that sticks into the periventricular layer of neuropil where it appears to contact a blood vessel; characterized by numerous cytoplasmic extensions. A tanycyte is a specialized elongated ventricular ependymal cell that has processes that extend to the outer, or pial, surface of the CNS.


lamellipodium membrane

The portion of the plasma membrane surrounding a lamellipodium.


MAD1 complex

A protein complex involved in the assembly of the mitotic checkpoint complex that in turn inhibits the anaphase promoting complex/cyclosome (APC/C).


chloroplast chromosome

A circular DNA molecule containing chloroplast encoded genes.


plastid chromosome

A circular DNA molecule containing plastid encoded genes.


Prp19 complex

A protein complex consisting of Prp19 and associated proteins that is involved in the transition from the precatalytic spliceosome to the activated form that catalyzes step 1 of splicing, and which remains associated with the spliceosome through the second catalytic step. It is widely conserved, found in both yeast and mammals, though the exact composition varies. In S. cerevisiae, it contains Prp19p, Ntc20p, Snt309p, Isy1p, Syf2p, Cwc2p, Prp46p, Clf1p, Cef1p, and Syf1p.


phenylalanine-tRNA ligase complex

An enzyme complex that catalyzes the ligation of phenylalanine to tRNA(Phe), forming L-phenylalanyl-tRNA(Phe).


IgX immunoglobulin complex

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


somatic spine

Spine emanating from the cell soma of a neuron.


nuclear membrane microtubule tethering complex

A nuclear membrane protein complex which connects the nuclear outer and inner membranes together, and links thereby links the nuclear lumen to cytoplasmic microtubules.


mitotic nuclear membrane microtubule tethering complex

A protein complex capable of interacting with the spindle pole body and the nuclear envelope, in order to embed the spindle pole body in the nuclear envelope at fusion sites of the inner and outer nuclear membrane.


glycinergic synapse

A synapse that uses glycine as a neurotransmitter.


PCSK9-LDLR complex

A protein complex consisting of the serine protease PCSK9 (proprotein convertase subtilisin/kexin-9) and a low-density lipoprotein receptor (LDLR). Interaction typically occurs through the epidermal growth factor-like repeat A (EGF-A) domain of the LDLR, and complex formation promotes degradation of the LDLR through the endosome/lysosome pathway.


platelet dense tubular network

A network of membrane-bounded compartments found in blood platelets, where they regulate platelet activation by sequestering or releasing calcium. The dense tubular network exists as thin elongated membranes in resting platelets, and undergoes a major ultrastructural change, to a rounded vesicular form, upon addition of thrombin.


cytoplasmic replication fork

The Y-shaped region of a cytoplasmic replicating DNA molecule, resulting from the separation of the DNA strands and in which the synthesis of new strands takes place. Also includes associated protein complexes.


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.


host cell lysosomal membrane

The lipid bilayer surrounding the host cell lysosome and separating its contents from the host cell cytoplasm.


mitochondrial proton-transporting ATP synthase complex, coupling factor F(o)

All non-F1 subunits of the mitochondrial hydrogen-transporting ATP synthase, including integral and peripheral mitochondrial inner membrane proteins.


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.


WASH complex

A protein complex that localizes at the surface of endosomes, where it recruits and activates the Arp2/3 complex to induce actin polymerization. In human, the WASH complex is composed of F-actin-capping protein subunits alpha and beta, WASH1, FAM21, KIAA1033, KIAA0196 and CCDC53.


oligosaccharyltransferase III complex

An oligosaccharyltransferase (OST) complex that contains the seven polypeptides found in OST complex I, plus heterotrimeric Sec61alpha-beta-gamma and the tetrameric TRAP complex. Of the three forms of mammalian OST complexes identified, the OSTIII complex has the strongest affinity for ribosomes.


cellular birth scar

Crater-like ring of chitinous scar tissue located on the surface of the daughter cell, in budding fungi, at the site of separation from the mother cell. It is formed after the newly emerged daughter cell separates, thereby marking the site of cytokinesis and septation.


cell cortex of growing cell tip

Any cell cortex that is part of a growing cell tip.


posterior cell cortex

The region that lies just beneath the plasma membrane in the part of a cell that is closest to the posterior as defined by the developing, or existing, anterior/posterior axis.


dendritic spine cytoplasm

The region of the neuronal cytoplasm located in dendritic spines.


lateral cell cortex

The region directly beneath the plasma membrane of the lateral portion of the cell.


pole plasm

Differentiated cytoplasm associated with a pole (animal, vegetal, anterior, or posterior) of an oocyte, egg or early embryo.


apical cortex

The region that lies just beneath the plasma membrane on the apical edge of a cell.


presynaptic endocytic zone cytoplasmic component

The cytoplasmic component of the presynaptic endocytic zone.


dendrite cytoplasm

All of the contents of a dendrite, excluding the surrounding plasma membrane.


equatorial cell cortex

The region of the cell cortex in a mitotically dividing cell that flanks the central spindle and corresponds to the site of actomyosin ring formation that results in cleavage furrow formation and ingression.


presynaptic active zone cytoplasmic component

A specialized region below the presynaptic membrane, characterized by electron-dense material, a specialized cytoskeletal matrix and accumulated (associated) synaptic vesicles.


cell cortex of cell tip

The region directly beneath the plasma membrane at the cell tip. The cell tip is the region at either end of the longest axis of a cylindrical or elongated cell.


cell cortex region

The complete extent of cell cortex that underlies some some region of the plasma membrane.


medial cortex

A medial cortical band overlaying the nucleus which acts as a landmark for contractile ring positioning and plays a role in cell cycle regulation.


cytoplasmic region

Any (proper) part of the cytoplasm of a single cell of sufficient size to still be considered cytoplasm.


ooplasm

The cytoplasm of an ovum.


postsynaptic endocytic zone cytoplasmic component

The cytoplasmic component of the postsynaptic endocytic zone.


cell leading edge cell cortex

The cell cortex of the leading edge of a cell.


apicomedial cortex

The region that lies just beneath the plasma membrane in the middle of the apical edge of a cell.


basal cortex

The region that lies just beneath the plasma membrane on the basal edge of a cell.


plasma membrane bounded cell projection cytoplasm

All of the contents of a plasma membrane bounded cell projection, excluding the plasma membrane surrounding the projection.


anterior cell cortex

The region that lies just beneath the plasma membrane in the part of a cell that is closest to the anterior as defined by the developing, or existing, anterior/posterior axis.


ciliary plasm

All of the contents of a cilium, excluding the plasma membrane surrounding the cilium.


cell cortex

The region of a cell that lies just beneath the plasma membrane and often, but not always, contains a network of actin filaments and associated proteins.


neuron projection cytoplasm

All of the contents of a plasma membrane bounded neuron projection, excluding the plasma membrane surrounding the projection.


sarcoplasm

The cytoplasm of a muscle cell; includes the sarcoplasmic reticulum.


cell cortex of non-growing cell tip

The region directly beneath the plasma membrane at the cell tip at which no growth takes place.


organellar small ribosomal subunit

The smaller of the two subunits of an organellar ribosome.


chloroplast small ribosomal subunit

The small subunit of a ribosome contained within a chloroplast.


plastid small ribosomal subunit

The smaller of the two subunits of a plastid ribosome.


dinoflagellate hypocone

The part of a dinoflagellate cell below the cingulum; also referred to as the posterior portion of a dinoflagellate cell. It is separated from the epicone by the cingulum.


Cul4-RING E3 ubiquitin ligase complex

A ubiquitin ligase complex in which a cullin from the Cul4 family and a RING domain protein form the catalytic core; substrate specificity is conferred by an adaptor protein.


Cul4B-RING E3 ubiquitin ligase complex

A ubiquitin ligase complex in which a cullin from the Cul4B subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by unknown subunits.


CLRC complex

An cullin-dependent E3 ubiquitin ligase/histone H3-K9 methyltransferase complex essential for heterochromatin assembly by RNAi.


cytosolic alpha-ketoglutarate dehydrogenase complex

Cytosolic complex that possesses alpha-ketoglutarate dehydrogenase activity.


nuclear outer membrane

The outer, i.e. cytoplasm-facing, lipid bilayer of the nuclear envelope; continuous with the endoplasmic reticulum of the cell and sometimes studded with ribosomes.


nuclear membrane

Either of the lipid bilayers that surround the nucleus and form the nuclear envelope; excludes the intermembrane space.


nuclear inner membrane

The inner, i.e. lumen-facing, lipid bilayer of the nuclear envelope.


Par3-APC-KIF3A complex

A protein complex that contains Par3, the tumor suppressor protein adenomatous polyposis coli (APC), and the kinesin-related protein KIF3A; involved in establishing neuronal cell polarity.


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.


radial spoke base 2

The short portion of the radial spoke 2 (RS2) that is directly anchored to the A microtubule of an axonemal microtubule doublet.


Heterodimeric complex that catalyzes the pyrophosphate-dependent phosphorylation of D-fructose 6-phosphate into D-fructose 1,6-bisphosphate.


germ tube

The slender tubular outgrowth first produced by most spores in germination.


Lsm2-8 complex

A heteroheptameric, nuclear protein complex composed of Lsm2, Lsm3, Lsm4, Lsm5, Lsm6, Lsm7, and Lsm8, or orthologs thereof, that selectively binds to snRNAs, in particular U6 or U6atac snRNAs, and also to unspliced transcripts localized within the nucleus.


NatB complex

A conserved complex that catalyzes the transfer of an acetyl group to the N-terminal residue of a protein acceptor molecule that has a Met-Glu, Met-Asp, Met-Asn, or Met-Met N-terminus. In Saccharomyces the complex includes Nat3p and Mdm20p.


SWI/SNF superfamily-type complex

A protein complex that contains an ortholog of the Saccharomyces ATPase Swi2/Snf2 as one of the catalytic subunit components (ATPase) and mediates assembly of nucleosomes, changes to the spacing or structure of nucleosomes, or some combination of those activities in a manner that requires ATP.


ATPase complex

A protein complex which is capable of ATPase activity.


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.


RSF complex

An ISWI complex that contains an ATPase subunit of the ISWI family (SNF2H in mammals) and an RSF1 homolog. It mediates nucleosome deposition and generates regularly spaced nucleosome arrays. In mammals, RSF is involved in regulation of transcription from RNA polymerase II promoters).


NoRC complex

An ISWI complex that contains an ATPase subunit of the ISWI family (specifically SNF2H in mammals, which contain two ISWI homologs) and a Tip5 homolog. In mammals, NoRC is involved in regulation of transcription from RNAP I and RNA polymerase III promoters.


Isw1a complex

An Isw1 complex that binds DNA and has nucleosome-stimulated ATPase activity. In S. cerevisiae, contains an Isw1p ATPase subunit in complex with Ioc3p.