photosystem II reaction center

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


photosystem II oxygen evolving complex

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A complex, composed of a cluster of manganese, calcium and chloride ions bound to extrinsic proteins, that catalyzes the splitting of water to O2 and 4 H+. In cyanobacteria there are five extrinsic proteins in OEC (PsbO, PsbP-like, PsbQ-like, PsbU and PsbV), while in plants there are only three (PsbO, PsbP and PsbQ).


cytoplasmic exosome (RNase complex)

A ribonuclease complex that has 3-prime to 5-prime processive hydrolytic exoribonuclease activity producing 5-prime-phosphomonoesters. Participates in a multitude of cellular RNA processing and degradation events preventing nuclear export and/or translation of aberrant RNAs. Restricted to processing linear and circular single-stranded RNAs (ssRNA) only. RNAs with complex secondary structures may have to be unwound or pre-processed by co-factors prior to entering the complex, esp if the 3-prime end is structured.


amyloid-beta complex

Protein complex involved in modulation of signaling and synaptic function in the brain, predominantly in the cerebral cortex and hippocampus. Forms dimers and multimers of amyloid beta peptide 40 and peptide 42 (proteolytic cleavage products of amyloid beta A4 protein, also known as amyloid beta precursor protein). Mostly found in the extracellular space with a proportion occurring as membrane-bound species. Influences synaptic plasticity through various receptors, mediates dendritic spine loss leading to decreased synapse density, inhibits long-term potentiation (LTP) and enhances long-term depression (LTD). Soluble multimeric form is the main pathogenic species linked to Alzheimer's disease.


IgD immunoglobulin complex

A protein complex composed of two identical immunoglobulin heavy chains of the IgD isotype and two identical immunoglobulin light chains, held together by disulfide bonds. An IgD 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.


IgE immunoglobulin complex

A protein complex composed of two identical immunoglobulin heavy chains of the IgE isotype and two identical immunoglobulin light chains, held together by disulfide bonds. An IgE 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.


ribonuclease III complex

A protein complex which is capable of ribonuclease III activity.


homodimeric serine palmitoyltransferase complex

A homodimeric complex which transfers a palmitoyl group onto serine, forming 3-dehydro-D-sphinganine.


nucleotide-activated protein kinase complex

A protein complex that possesses nucleotide-dependent protein kinase activity. The nucleotide can be AMP (in S. pombe and human) or ADP (in S. cerevisiae).


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


histone mRNA stem-loop binding complex

A protein-containing complex composed of a stem-loop binding protein (in most species SLBP) and its interacting partner (SLIP1 or MIF4GD in most species) that binds to the histone mRNA (hmRNA) 3-prime-stem-loop structure. Facilitates hmRNA translation initiation and may also be involved in its processing and nuclear export.


CAF-1 complex

A conserved heterotrimeric protein complex that promotes histone H3 and H4 deposition onto newly synthesized DNA during replication or DNA repair; specifically facilitates replication-dependent nucleosome assembly with the major histone H3 (H3.1). In many species the CAF-1 subunits are designated p150, p60, and p48.


Myo2p-Vac17p-Vac8p transport complex

A protein complex that is involved in transport of vacuoles to a newly formed daughter cell. In yeast, this complex is composed of Myo2p, Vac17p, and Vac8p.


new spindle pole body SIN signaling complex

A SIN signaling complex associated with the new mitotic spindle pole body during anaphase and characterized by the presence activated (GTP bound) GTPase (Spg1 in fission yeast) to activate SIN signaling.


radial spoke neck

The radial spoke neck is a complex that connects the spoke stalk to the head.


counting factor complex

A secreted multiprotein complex composed of 4 proteins, regulating group size during aggregation in cooperative development. An example of this complex is found in Dictyostelium discoideum.


laminin-1 complex

A laminin complex composed of alpha1, beta1 and gamma1 polypeptide chains.


IgY immunoglobulin complex

A protein complex composed of two identical immunoglobulin heavy chains of the IgY isotype and two identical immunoglobulin light chains, held together by disulfide bonds. An IgY 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.


A protein complex capable of catalyzing the transfer of a phosphate group from one position to another within a single molecule.


thiazole synthase complex

A protein complex which is capable of thiazole synthase activity.


C/EBP complex

A dimeric, sequence specific DNA-binding transcription factor complex regulating the expression of genes involved in immune and inflammatory responses. Exists at least as alpha and beta homodimeric forms. Binds to regulatory regions of several acute-phase and cytokines genes and probably plays a role in the regulation of acute-phase reaction, inflammation and hemopoiesis. The consensus recognition site is 5'-T[TG]NNGNAA[TG]-3'. Transcription factor activity is inhibited by binding of CHOP forming heterodimers with alternative transcription factor activities.


laminin-2 complex

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


MAML2-RBP-Jkappa-ICN3 complex

A protein complex that consists of the intracellular domain of Notch3 (ICN3), the DNA-binding transcription factor RBP-Jkappa, and the transcriptional coactivator Mastermind-like-2 (MAML2); the complex is involved in transcriptional activation in response to Notch-mediated signaling.


RNA polymerase IV transcription regulator complex

A transcription factor complex that acts at a regulatory region of a gene transcribed by RNA polymerase IV.


xanthine dehydrogenase complex

A homodimeric protein complex having xanthine dehydrogenase activity.


EGFR-Shc-Grb2-Sos complex

A protein complex that contains the epidermal growth factor receptor (EGFR), Grb2, the adaptor protein SHC and the guanine nucleotide exchange factor Sos (or an ortholog thereof, such as mSos1), and is involved in linking EGFR activation to the p21-Ras pathway.


nucleotide-excision repair factor 4 complex

One of several protein complexes involved in nucleotide-excision repair; possesses DNA damage recognition and DNA-dependent ATPase activities. In S. cerevisiae, it is composed of Rad7p and Rad16p.


Rad17 RFC-like complex

A pentameric protein complex related to replication factor C, which loads a trimeric complex of checkpoint proteins (known as the checkpoint clamp or 9-1-1 complex) onto DNA at damage sites; functions in DNA damage cell cycle checkpoints. In Schizosaccharomyces pombe the subunits are known as Rad17, Rfc2, Rfc3, Rfc4, and Rfc5, while in Saccharomyces cerevisiae the subunits are known as Rad24p, Rfc2p, Rfc3p, Rfc4p, and Rfc5p.


myosin III complex

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


SOD1-Bcl-2 complex

A heterodimeric protein complex formed of superoxide dismutase 1 and Bcl-2. Complex formation is thought to link superoxide dismutase to an apoptotic pathway.


iron-iron nitrogenase complex

An enzyme complex containing an iron-iron cluster found in species such as the photosynthetic bacterium Rhodobacter capsulatus. It is composed of two main subunits, dinitrogenase and nitrogenase reductase. Dinitrogenase, the iron-iron containing subunit, has an alpha1-beta2 or alpha2-beta2 structure, and the nitrogenase reductase subunit is a homodimer. Functions in the catalysis of the formation of oxidized ferredoxin and ammonia from reduced ferredoxin and nitrogen.


gamma-secretase-Delta1 complex

A protein complex that is formed by the association of the Notch ligand Delta1 with the gamma-secretase complex.


I-kappaB/NF-kappaB complex

A protein complex containing an inhibitory-kappaB (I-kappaB/IKB) protein and one or more copies of an NF-kappaB protein. In the resting state, NF-kappaB dimers are bound to I-kappaB proteins, sequestering NF-kappaB in the cytoplasm.


A protein complex that enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: Ca2+(in) + H+(out) = Ca2+(out) + H+(in).


ERBB4-ERBB4 complex

A homodimeric complex containing two monomers of the tyrosine kinase receptor ERBB4 (also called HER4).


synapsis initiation complex

A SUMO-E3 ligase complex capable of promoting synapsis, the meiotic cell cycle process where side by side pairing and physical juxtaposition of homologous chromosomes is created during meiotic prophase.


DnaB-DnaG complex

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


SCF-Pof5 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Pof5 in S. pombe (YDR306C in S. cerevisiae).


collagen type XXIII trimer

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


alpha6-beta1 integrin-CYR61 complex

A protein complex that consists of an alpha6-beta1 integrin complex bound to CYR61, a cysteine-rich protein involved in angiogenesis.


heterochromatin domain

A region of heterochromatin that is formed dynamically under specific growth conditions by a process that requires RNAi, and is enriched in histone H3 methylated on lysine 9 (H3K9me).


A SNARE complex that contains VAMP4, syntaxin 6, syntaxin 16, and Vti1a (or orthologs thereof).


A protein complex that possesses glutamyl-tRNA(Gln) amidotransferase activity, and therefore creates Gln-tRNA by amidating Glu-tRNA; usually composed of 3 subunits: A, B, and C. Note that the C subunit may not be required in all organisms.


Cul8-RING ubiquitin ligase complex

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


thylakoid light-harvesting complex

A thylakoid membrane complex of chlorophylls a and b together with chlorophyll a-b binding proteins. In addition, LHCs contain a number of other proteins, the function of which is speculative, together with accessory pigments. The LHCs capture and transfer energy to photosystems I and II. An example of this is found in Arabidopsis thaliana.


tRNA (m2G10) methyltransferase complex

A protein complex required for the methylation of the guanosine nucleotide at position 10 (m2G10) in tRNA. In S. cerevisiae, this complex consists of at least two subunits, Trm11p and Trm112p.


DNA polymerase III complex

The DNA polymerase III holoenzyme is a complex that contains 10 different types of subunits. These subunits are organized into 3 functionally essential sub-assemblies: the pol III core, the beta sliding clamp processivity factor and the clamp-loading complex. The pol III core carries out the polymerase and the 3'-5' exonuclease proofreading activities. The polymerase is tethered to the template via the sliding clamp processivity factor. The clamp-loading complex assembles the beta processivity factor onto the primer template and plays a central role in the organization and communication at the replication fork.


glycine reductase complex

Complex that possesses glycine reductase activity; usually comprises three subunits, of which two are selenoproteins; the subunits are typically designated selenoprotein A, selenoprotein B and protein C.


ERCC4-ERCC1 complex

A heterodimeric nucleotide-excision repair complex that has endonuclease activity specific for bubble structures characteristic of certain DNA lesions. The subunits are known as XPF/ERCC4 and ERCC1 in mammals, and Rad1p and Rad10p in S. cerevisiae.


cyanelle ribonuclease P complex

A ribonuclease P complex located in the cyanelle, where it catalyzes the 5' endonucleolytic cleavage of precursor tRNAs to yield mature tRNAs. The best characterized cyanelle ribonuclease P complex, from the alga Cyanophora paradoxa, contains a single RNA molecule that is necessary but not sufficient for catalysis, and several protein molecules.


shelterin complex

A nuclear telomere cap complex that is formed by the association of telomeric ssDNA- and dsDNA-binding proteins with telomeric DNA, and is involved in telomere protection and recruitment of telomerase. The complex is known to contain TERF1, TERF2, POT1, RAP1, TINF2 and ACD in mammalian cells, and Pot1, Tpz1, Rap1, Rif1, Rif2 and Taz1 in Saccharomyces. Taz1 and Rap1 (or their mammalian equivalents) form a dsDNA-binding subcomplex, Pot1 and Tpz1 form an ssDNA-binding subcomplex, and the two subcomplexes are bridged by Poz1, which acts as an effector molecule along with Ccq1.


urease complex

A multiprotein nickel-containing complex that possesses urease activity (catalysis of the hydrolysis of urea to ammonia and carbon dioxide).


Cry-Per complex

Nuclear transcriptional repressor complex that is capable of negatively regulating CLOCK-BMAL-dependent transactivation of genes in a delayed negative feedback manner which generates circadian rhythms.


iNOS-S100A8/A9 complex

A protein complex capable of stimulus-inducible nitric-oxide synthase activity. S-nitrosylates cysteine residues in target proteins, a principal mechanism of nitric oxide (NO)-mediated signal transduction. In mammals consists of NOS2, S100A8 and S100A9. S100A9 acts both as an adaptor linking NOS2 to its target and as a transnitrosylase that transfers the nitric oxide moiety from NOS2 to its target, via its own S-nitrosylated cysteine.


IgM immunoglobulin complex

A protein complex composed of two identical immunoglobulin heavy chains of the IgM isotype and two identical immunoglobulin light chains, held together by disulfide bonds, and in its circulating form complexed with J chain in polymeric forms. An IgM 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.


integrin alpha2-beta1 complex

An integrin complex that comprises one alpha2 subunit and one beta1 subunit.


peroxisomal importomer complex

A protein complex responsible for transporting proteins into the peroxisomal matrix. An example of this complex is Pex14 found in S. cerevisae which has 9 core components and 12 transient interaction partners.


syntrophin complex

A protein complex that includes alpha-, beta1-, beta2-syntrophins and syntrophin-like proteins; the syntrophin complex binds to the second half of the carboxy-terminal domain of dystrophin; also associates with neuronal nitric oxide synthase.


chylomicron remnant

A lipoprotein particle that is derived from a mature chylomicron particle by the removal of triglycerides from the chylomicron core by lipoprotein lipase and the subsequent loss of surface components. It characteristically contains apolipoprotein E (APOE) and is cleared from the blood by the liver.


box C/D RNP complex

A ribonucleoprotein complex containing a box C/D type RNA that can carry out ribose-2'-O-methylation of target RNAs. Box C/D type RNAs are widespread in eukaryotes and in Archaea, suggesting that an RNA-based guide mechanism for directing specific RNA 2'-O-ribose methylations was present in the common ancestor of Archaea and Eukarya.


Ku70:Ku80 complex

Heterodimeric protein complex composed of a 70 kDa and a 80 kDa subunit, binds DNA through a channel formed by the heterodimer. Functions in DNA double stranded break repair, chromosome maintenance, transcription regulation, V(D)J recombination, and activation of DNA-PK.


Ddb1-Ckn1 complex

A heterodimeric nucleotide-excision repair complex that is involved in transcription-coupled repair. The subunits are known as Ddb1 and Ckn1 in S. pombe; Ddb1 contains a motif called the DDB-box that interacts with adaptor proteins for DDB1/cullin 4 ubiquitin ligases.


A protein complex which is capable of phosphatidylinositol transporter activity.


nuclear proteasome core complex, beta-subunit complex

The subunits forming the inner ring of the core complex of a proteasome located in the nucleus of a cell.


integrin alpha10-beta1 complex

An integrin complex that comprises one alpha10 subunit and one beta1 subunit.


A protein complex that consists of an alphaE-beta7 integrin complex bound to E-cadherin.


G protein-coupled receptor complex

A protein complex that contains G protein-coupled receptors.


collagen type XVI trimer

A collagen trimer containing alpha(XVI) chains; type XVI trimers can associate with microfibrils.


macrophage migration inhibitory factor receptor complex

A protein complex that binds macrophage migration inhibitory factor. Comprises CD74 and CD44 cell surface proteins.


KICSTOR complex

A protein complex that regulates the TORC1 signaling pathway in response to nutrients. The KICSTOR complex is composed of KPTN, ITFG2, C12orf66 and SZT2.


transcription factor TFIIA complex

A component of the transcription machinery of RNA Polymerase II. In humans, TFIIA is a heterotrimer composed of an alpha (P35), beta (P19) and gamma subunits (P12).


histone H3-containing nucleosome

A complex comprised of DNA wound around a multisubunit core and associated proteins containing the histone H3, which forms the primary packing unit of DNA into higher order structures.


ERBB4:ERBB2 complex

A heterodimeric complex between the tyrosine kinase receptor ERBB2 and a ligand-activated receptor ERBB4. ERBB2, which does not bind any known ligand, is activated through formation of a heterodimer with another ligand-activated ERBB family member such as ERBB4.


myosin I complex

A myosin complex containing a class I myosin heavy chain and associated light chains; myosin I heavy chains are single-headed, possess tails of various lengths, and do not self-associate into bipolar filaments; myosin I complexes are involved in diverse processes related to membrane traffic and cell movement.


BAK complex

An oligomeric protein complex consisting of BAK, a member of the Bcl-2 family of anti- and proapoptotic regulators.


chloroplast ATP synthase complex

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


integrin alphaD-beta2 complex

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


SCF-Dia2/Pof3 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Dia2 in S. cerevisiae (Pof3 in S. pombe).


Ddb1-Wdr21 complex

A heterodimeric nucleotide-excision repair complex that is involved in transcription-coupled repair. The subunits are known as Ddb1 and Wdr21 in S. pombe; Ddb1 contains a motif called the DDB-box that interacts with adaptor proteins for DDB1/cullin 4 ubiquitin ligases.


ATF1-ATF4 transcription factor complex

Transcription factor complex consisting of ATF1 and ATF4 subunits that is capable of binding to cAMP response element (CRE) (consensus: 5'-GTGACGT[AC][AG]-3') of the GRP78 (HSPA5) promoter. Involved in the ER stress response pathway.


retromer, cargo-selective complex

The trimeric subcomplex of the retromer, believed to be closely associated with the membrane. This trimeric complex is responsible for recognizing and binding to cargo molecules. The complex comprises three Vps proteins in both yeast and mammalian cells: Vps35p, Vps29p, and Vps26p in yeast, and VPS35, VPS29 and VPS26A or VPS26B in mammals.


SBF transcription complex

A protein complex that binds to the Swi4/6 cell cycle box (SCB) promoter element, consensus sequence CRCGAAA, and activates transcription during the G1/S transition of the cell cycle. In Saccharomyces, the complex contains a heterodimer of the DNA binding protein Swi4p and the activator Swi6p, and is associated with additional proteins known as Whi5p and Msa1p.


alpha9-beta1 integrin-ADAM1 complex

A protein complex that consists of an alpha9-beta1 integrin complex bound to the transmembrane metallopeptidase ADAM1.


oligosaccharyltransferase II complex

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


alphaV-beta3 integrin-CD98 complex

A protein complex that consists of an alphaV-beta3 integrin complex bound to the cell surface antigen CD98.


nucleolar exosome (RNase complex)

A ribonuclease complex that has 3-prime to 5-prime distributive hydrolytic exoribonuclease activity and in some taxa (e.g. yeast) endoribonuclease activity, producing 5-prime-phosphomonoesters. Participates in a multitude of cellular RNA processing and degradation events preventing nuclear export and/or translation of aberrant RNAs. Restricted to processing linear and circular single-stranded RNAs (ssRNA) only. RNAs with complex secondary structures may have to be unwound or pre-processed by co-factors prior to entering the complex, esp if the 3-prime end is structured.


microprocessor complex

A protein complex that binds to heme and to pri-miRNAs, and is required for the formation of a pre-microRNA (pre-miRNA), the initial step of microRNA (miRNA) biogenesis. The complex is composed of the double-stranded-RNA-specific RNase Drosha (also called RNASEN) and the RNA-binding protein DGCR8 (heme-free or heme-bound forms). Within the complex, DGCR8 function as a molecular anchor necessary for the recognition of pri-miRNA at dsRNA-ssRNA junction and directs RNASEN/Drosha to cleave the 3' and 5' strands of a stem-loop to release hairpin-shaped pre-miRNAs.


Hda-beta clamp complex

A protein complex involved in inactivating the function of DnaA and thereby preventing multiple events of replication initiation. In E. coli, this complex is composed of the beta clamp (DnaN) and Hda.


m7G(5')pppN diphosphatase complex

A homodimeric protein complex that catalyzes the reaction: 7-methylguanosine-5'-triphospho-5'-pholynucleotide + H20 = 7-methylguanosine-5'-phosphate + polynucleotide.


MLL1/2 complex

A protein complex that can methylate lysine-4 of histone H3, and which contains either of the protein subunits MLL1 or MLL2 in human, or equivalent in other species.


PKM2 protein kinase complex

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


BAX complex

An oligomeric protein complex consisting of BAX, a member of the Bcl-2 family of anti- and proapoptotic regulators.


A protein complex that consists of an alpha9-beta1 integrin complex bound to thrombospondin-1.


multimerin complex

Glycoprotein complex of the C1q/TNF superfamily involved in cell adhesion. A homotrimer that will combine to form supramolecular Multimerin structures.


luminal surveillance complex

A multiprotein complex that recognizes ERAD-luminal misfolded substrates and brings them to the ubiquitination/extraction machinery. In yeast, this complex consists of Yos9p, Kar2p and Hrd3p proteins.


integrin alpha1-beta1 complex

An integrin complex that comprises one alpha1 subunit and one beta1 subunit.


endosomal scaffold complex

A protein complex that contains MAPKSP1 (MP1, Map2k1ip1) and ROBLD3 (p14, Mapbpip), is anchored to late endosomes, and is involved in selective activation of the ERK1 in ERK/MAPK signaling.


pre-primosome complex

Any of the protein-DNA complexes that contain a DNA helicase and associated protein(s) at the origin of replication, and build up to assembling the core primosome. The associated protein(s) chaperone the helicase to the DNA, and assembly of the pre-primosome is essential for the initiation or restart of replication. Pre-primosome complexes lack a primase component.


myosin XVII complex

A myosin complex containing one or more class XVII myosin heavy chains and associated light chains.


integrin alphaIIb-beta3 complex

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


nascent polypeptide-associated complex

A heterodimeric protein complex that can reversibly bind to ribosomes, and is located in direct proximity to newly synthesized polypeptide chains as they emerge from the ribosome.


DnaB-DnaC-Rep-PriC complex

A protein-DNA complex consisting of the helicase loading complex DnaB-DnaC, replication restart proteins Rep and PriC, and associated DNA. Involved in the restart of DNA replication after a stalled replication fork has been repaired.


plasma membrane proton-transporting ATP synthase complex, catalytic core F(1)

The catalytic sector of the plasma membrane hydrogen-transporting ATP synthase; it comprises the catalytic core and central stalk, and is peripherally associated with the plasma membrane when the entire ATP synthase is assembled. Examples of this component are found in Bacterial species.


mitochondrial processing peptidase complex

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


proteasome core complex

A multisubunit barrel shaped endoprotease complex, which is the core of the proteasome complex.


S100A9 complex

A protein complex composed of a S100A9 dimer and capable of binding to toll-like receptor 4 (TLR4) and the receptor for advanced glycation end products (RAGE) initiating signal transduction through NF-kappa-B pathways. Transports arachidonic acid between the cytosol and the NADPH oxidase complex at the plasma membrane in neutrophils as part of an inflammatory signal cascade leading to an oxidative burst. Complexes with microtubules to increase cell motility.


neurotransmitter receptor complex

Any protein complex that is capable of functioning as a neurotransmitter receptor.


ubiquitin conjugating enzyme complex

Any complex that possesses ubiquitin conjugating enzyme activity.


laminin-4 complex

A laminin complex composed of alpha2, beta2 and gamma1 polypeptide chains.


An enzyme complex that catalyzes the transfer of a phosphate from protein N(PI)-phosphohistidine to a sugar molecule. It is enzyme II of the phosphotransferase system.


BRCA1-Rad51 complex

A protein complex that contains BRCA1 and Rad 51, and is involved in the control of recombination and of genome integrity.


chloroplast thylakoid membrane protein complex

A protein complex that is part of a chloroplast thylakoid membrane.


Lid2 complex

A protein complex involved in regulation of chromatin remodeling. In Schizosaccharomyces the complex contains Lid2, Ash2, Jmj3, Snt2, and Sdc1.


DnaA-Dps complex

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


NADH dehydrogenase complex (plastoquinone)

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


alpha9-beta1 integrin-VEGF-A complex

A protein complex that consists of an alpha9-beta1 integrin complex bound to vascular endothelial growth factor A.


axonemal nexin link

A protein complex found in the axoneme of eukaryotic cilia and flagella. It forms interconnections between the microtubule outer doublets that surround the inner central pair of microtubules.


myosin XV complex

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


A protein complex which is capable of pyrroline-5-carboxylate reductase activity.


chaperonin ATPase complex

Multisubunit protein complex with 2x7 (Type I, in most cells) or 2x8 (Type II, in Archaea) ATP-binding sites involved in maintaining an unfolded polypeptide structure before folding or to entry into mitochondria and chloroplasts.


telomerase holoenzyme complex

Telomerase is a ribonucleoprotein enzyme complex, with a minimal catalytic core composed of a catalytic reverse transcriptase subunit and an RNA subunit that provides the template for telomeric DNA addition. In vivo, the holoenzyme complex often contains additional subunits.


myosin XI complex

A myosin complex containing a dimer of class XI myosin heavy chains and associated light chains. Myosin XI heavy chain sizes are similar in molecular structure to the class V myosins with 5 to 6 IQ motifs and tail regions with predicted coiled coil domains (forming dimeric molecules) and large C-terminal regions.


alpha5-beta5-fibronectin-SFRP2 complex

A protein complex that consists of an alpha5-beta5 integrin complex bound to fibronectin and secreted frizzled-related protein 2.


Rad6-Rad18 complex

A ubiquitin ligase complex found to be involved in post-replicative bypass of UV-damaged DNA and UV mutagenesis. In S. cerevisiae, the complex contains the ubiquitin conjugating enzyme Rad6 and Rad18, a protein containing a RING finger motif and a nucleotide binding motif. The yeast Rad6-Rad18 heterodimer has ubiquitin conjugating activity, binds single-stranded DNA, and possesses single-stranded DNA-dependent ATPase activity.


PSII associated light-harvesting complex II, peripheral complex, LHCIIb subcomplex

A pigment protein complex that forms part of the photosystem II associated light-harvesting complex II; contains two proteins (usually about 28 and 27 kDa), and may contain a third; peripherally located relative to other LHC polypeptides.


reelin complex

An extracellular complex that binds lipoprotein receptors VLDLR and APOER2, cadherin-related neuronal receptors (CNRs) or alpha3beta1 integrin and induces various downstream, reelin-dependent, phosphorylation cascades. It ultimately affects polarization, differentiation, neuronal migration and layer formation in the embryonic brain and neuron growth, maturation, and synaptic activity in the postnatal and adult brain.


APC-IQGAP1-Rac1 complex

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


haptoglobin-hemoglobin complex

A protein complex formed by the stable binding of a haptoglobin to hemoglobin.


Pi Mi complex

A transcription factor complex composed of a homeodomain protein and the M-specific peptide Mi that acts at the regulatory region of genes required for the activation of meiosis.


chaperone-mediated autophagy translocation complex

A lysosomal membrane protein complex that enables the translocation of a target protein across the lysosomal membrane as part of chaperone-mediated autophagy.


integrin alpha11-beta1 complex

An integrin complex that comprises one alpha11 subunit and one beta1 subunit.


mitochondrial proton-transporting ATP synthase, central stalk

One of two stalks that connect the catalytic core of the hydrogen-transporting ATP synthase to the mitochondrial membrane-associated F0 proteins; rotates within the catalytic core during catalysis.


Kelch-containing formin regulatory complex

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


hydroxyisourate hydrolase complex

A hydrolase complex that converts 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline. This is the second step of the three-step enzymatic reaction that degrades uric acid to (S)-allantoin.


INA complex

A protein complex located in the inner membrane of mitochondria that is involved in the assembly of the peripheral (or stator) stalk of the mitochondrial proton-transporting ATP synthase (also known as the F1F0 ATP synthase). In budding yeast, this complex includes Ina22p and Ina17p.


type I protein secretion system complex

A complex of three secretory proteins that carry out secretion in the type I secretion system: an inner membrane transport ATPase (termed ABC protein for ATP-binding cassette), which provides the energy for protein secretion; an outer membrane protein, which is exported via the sec pathway; and a membrane fusion protein, which is anchored in the inner membrane and spans the periplasmic space.


heterotetrameric ADPG pyrophosphorylase complex

A protein complex composed of four different subunits that possesses ADPG pyrophosphorylase activity. An example of this process is found in Mus musculus.


type II protein secretion system complex

A large protein complex, containing 12-15 subunits, that spans the cell envelope of Gram-negative bacteria and mediates the movement of proteins into the extracellular environment. The complex includes a component in the cytoplasm, an inner membrane subcomplex that reaches into the periplasmic compartment and a secretion pore in the outer membrane. Proteins using the Type II pathway are transported across the cytoplasmic membrane by the Sec or Tat complex.


tricarboxylic acid cycle enzyme complex

Any of the heteromeric enzymes that act in the TCA cycle.


U7 snRNP

A ribonucleoprotein complex that contains the U7 snRNA and is required for the 3'-end processing of replication-dependent histone pre-mRNAs.


laminin complex

A large, extracellular glycoprotein complex composed of three different polypeptide chains, alpha, beta and gamma. Provides an integral part of the structural scaffolding of basement membranes.


serine C-palmitoyltransferase complex

An enzyme complex that catalyzes the transfer of a palmitoyl on to serine, forming 3-dehydro-D-sphinganine.


3-isopropylmalate dehydratase complex

A heterodimeric enzyme complex composed of subunits leuC and leuD. Catalyzes the isomerization between 2-isopropylmalate and 3-isopropylmalate, via the formation of 2-isopropylmaleate.


sodium ion-transporting two-sector ATPase complex

A large protein complex that catalyzes the synthesis or hydrolysis of ATP by a rotational mechanism, coupled to the transport of sodium ions across a membrane. The complex comprises a membrane sector (F0 or V0) that carries out ion transport and a cytoplasmic compartment sector (F1 or V1) that catalyzes ATP synthesis or hydrolysis.


glideosome

A protein complex composed of at least GAP45 (gliding-associated protein), GAP50 and myosin heavy and light chains. Anchored via GAP50 to the inner membrane complex of motile and invasive forms of apicomplexan parasites and regulates parasite gliding motility and invasion of host cells.


HDA1 complex

A tetrameric histone deacetylase complex that contains a Class II deacetylase catalytic subunit. In S. cerevisiae it is composed of two Hda1p subunits along with Hda2p and Hda3p.


mitochondrial mRNA editing complex

An mRNA editing complex found in the mitochondrion. The best characterized example is that of Trypanosoma brucei, which catalyzes the insertion and deletion of uridylates.


axonemal heterotrimeric kinesin-II complex

A kinesin complex found in eukaryotic axonemes that contains two distinct plus end-directed kinesin motor proteins and at least one accessory subunit, and that functions in the anterograde transport of molecules (cargo) from the basal body to the distal tip of the axoneme.


basement membrane collagen trimer

Any collagen timer that is part of a basement membrane.


condensin complex

A multisubunit protein complex that plays a central role in chromosome condensation in meiosis and mitosis.


inhibin complex

Heterodimeric hormone composed of an inhibin alpha subunit complexed with either an inhibin beta-A subunit, to form inhibin A, or an inhibin beta-B subunit, to form inhibin B.


oncostatin-M receptor complex

A heterodimeric receptor for the cytokine oncostatin-M (OSM). In humans the receptor complex is made up of the gene products gp130 and OSMR-beta.


DASH complex

A large protein complex, containing around 8-10 subunits in yeast, including Duo1p, Dam1p, Dad1p and Ask1p. The complex forms part of the outer kinetochore, associates with microtubules when the kinetochore attaches to the spindle, and plays a role in spindle attachment, chromosome segregation and spindle stability.


RAD6-UBR2 ubiquitin ligase complex

A ubiquitin ligase complex consisting of RAD6 and UBR2 components. It may act in a quality control pathway for proteins synthesized on cytosolic ribosomes. The UBR2 component lacks sequence motifs required for N-end rule degradation.


proteasome core complex, beta-subunit complex

The proteasome core subcomplex that constitutes the two inner rings of the proteasome core complex. An example of this component is found in Mus musculus.


FHL3-CREB complex

A protein complex that contains CREB and FHL3, and is involved in transcriptional regulation.


chromatophore ribulose bisphosphate carboxylase complex

A complex, located in the chromatophore, containing either both large and small subunits or just small subunits which carries out the activity of producing 3-phosphoglycerate from carbon dioxide and ribulose-1,5-bisphosphate.


SREBP-SCAP-Insig complex

A protein complex formed by the association of sterol regulatory element binding protein (SREBP), SREBP-cleavage-activating protein (SCAP), and an Insig protein (Insig-1 or Insig-2) in the ER membrane.


A protein complex that consists of an alphav-beta3 integrin complex bound to insulin-like growth factor-1 (IGF-1) and type I insulin-like growth factor receptor (IGF1R). IGF1R is a heterotetramer that consists of two alpha-subunits and two beta-subunits.


dynactin complex

A 20S multiprotein assembly of total mass about 1.2 MDa that activates dynein-based activity in vivo. A large structural component of the complex is an actin-like 40 nm filament composed of actin-related protein, to which other components attach.


collagen type XX trimer

A collagen homotrimer of alpha1(XX) chains.


GTPase complex

A protein complex which is capable of GTPase activity.


classical-complement-pathway C3/C5 convertase complex

A heterodimeric protein complex that catalyzes the cleavage of complement components C3 and C5, and acts in the classical pathway of complement activation; consists of one monomer of C2a and one monomer of C4b; C2a is the catalytic subunit, but cannot catalyze cleavage alone.


starch utilization system complex

A bacterial cell envelope-associated multiprotein system, which binds and degrades starch.


methyl accepting chemotaxis protein complex

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


transcription-coupled nucleotide-excision repair, DNA damage recognition complex

A protein complex that is capable of identifying lesions in DNA on the actively transcribed strand of the DNA duplex as well as a small subset of lesions not recognized by the general nucleotide-excision repair pathway. The wide range of substrate specificity suggests that the repair complex recognizes distortions in the DNA helix. It subsequently recruits a nucleotide-excision repair, preincision complex.


RNAi effector complex

Any protein complex that mediates the effects of small interfering RNAs on gene expression. Most known examples contain one or more members of the Argonaute family of proteins.


transcription factor TFIIIC1 complex

A transcription factor complex that forms part of the TFIIIC complex, observed in human. The complex is poorly characterized, but contains the 250-kDa form of HsBdp1, and is thought to include nuclear factor 1 (NF1). It stimulates binding by human TFIIIC2 and is required for transcription activity.


transforming growth factor beta activated kinase 1 complex

A protein complex that possesses protein kinase activity and activates the I-kappa B kinase complex (IKK) and mitogen-activated protein (MAP) kinases in response to TRAF6 signaling. It comprises the catalytic subunit TAK1 complexed to the regulatory subunits, termed TABs (TAK1-binding subunits).


nuclear proteasome regulatory particle, base subcomplex

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


Vps55/Vps68 complex

A membrane-associated protein complex that is required for a late stage of endosomal transport. In budding yeast, this complex consists of Vps55p and Vps68p proteins.


DPS complex

A protein serine/threonine phosphatase complex that in S. pombe consists of the proteins Dis2, Ppn1, and Swd22.


Wnt signalosome

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


PUMA-BCL-2 complex

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


RISC-loading complex

A trimeric protein complex required for the formation of a mature RNA-induced silencing complex (RISC). In humans the complex is composed of the endonuclease Dicer (DICER1), TRBP (TARBP2) and the Argonaute protein Ago2 (EIF2C2/AGO2). Within the complex, Dicer and TRBP are required to process precursor miRNAs (pre-miRNAs) to mature miRNAs and then load them onto Ago2. Ago2 bound to the mature miRNA constitutes the minimal RISC and may subsequently dissociate from Dicer and TRBP. This complex has endoribonuclease activity.


Lsm-containing SMN-Sm protein complex

An SMN-Sm protein complex formed by the association of the methylated Sm proteins B/B', D3, E, F, and G, and Lsm10 and Lsm11, with the SMN complex. This complex forms Sm cores on U7 snRNA.


Bcl3-Bcl10 complex

A protein complex containing Bcl3 and Bcl10, which forms when Akt1 is activated by TNF-alpha to phosphorylate Bcl10; the Bcl3-Bcl10 complex is translocated to the nucleus.


DNA recombinase complex

A protein-DNA complex consisting of a higher-order oligomer of strand exchange proteins (recombinases) on single-stranded DNA.


PSI associated light-harvesting complex I, LHCIa subcomplex

A pigment protein complex that forms part of the photosystem I associated light-harvesting complex I; contains two proteins (usually about 24 and 21.5 kDa); has a fluorescence maximum between 680 and 690 nm.


laminin-522 complex

A laminin complex composed of alpha5, beta2 and gamma2 polypeptide chains.


DiaA complex

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


trans-synaptic protein complex

A protein complex that spans the synaptic cleft and has parts in both the pre- and post-synaptic membranes.


exomer complex

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


cobalamin transport complex

Protein complex facilitating ATP-dependent cobalamin (vitamin B12) transport through inner cell membrane (periplasm to cytoplasm) in Gram-negative bacteria. In E. coli the system is composed of a periplasmic cobalamin-binding protein (BtuF), an integral membrane homodimer, BtuC, and a cytoplasmic ATP-binding homodimer BtuD.


MAML3-RBP-Jkappa-ICN4 complex

A protein complex that consists of the intracellular domain of Notch4 (ICN4), the DNA-binding transcription factor RBP-Jkappa, and the transcriptional coactivator Mastermind-like-3 (MAML3); the complex is involved in transcriptional activation in response to Notch-mediated signaling.


An enzyme complex composed of 2-4 or more subunits, which usually contains nonheme iron and requires ATP for catalysis. Catalyzes the formation of 2'-deoxyribonucleoside diphosphate from ribonucleoside diphosphate, using either thioredoxin disulfide or glutaredoxin disulfide as an acceptor.


methyl-tetrahydromethanopterin:coenzyme M methyltransferase complex

A protein complex consisted of eight polypeptides. This complex catalyzes the formation of methyl-coenzyme M and H4MPT from N5-methyl-H4MPT and CoM during methanogenesis.


cytosolic aryl hydrocarbon receptor complex

An aryl hydrocarbon receptor complex found in the cytosol, in which the ligand-binding subunit AhR is not bound to ligand; consists of AhR, two molecules of HSP90, the protein kinase c-Src, and the immunophilin XAP2/AIP.


methionyl glutamyl tRNA synthetase complex

A complex consisting of methionyl- and glutamyl-tRNA synthetases. The tRNA synthetases present in the complex bind to their cognate tRNAs more efficiently than they do as monomers.


glutamate-tRNA ligase complex

An enzyme complex that catalyzes the ligation of glutamate and tRNA(Glu) to form glutamyl-tRNA(Glu).


radial spoke base

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


interleukin-4 receptor complex

A protein complex that binds interleukin-4 (IL-4) and consists of an alpha chain that binds IL-4 with high affinity and a gamma common chain that also forms part of the interleukin-2 receptor.


iron-sulfur cluster transfer complex

A protein complex capable of catalyzing the transfer of an iron-sulfur (Fe-S) cluster from one compound (donor) to another (acceptor).


photosystem I reaction center

A photochemical system containing P700, the chlorophyll a dimer that functions as a primary electron donor. Functioning as a light-dependent plastocyanin-ferredoxin oxidoreductase, it transfers electrons from plastocyanin to ferredoxin.


fatty-acyl-CoA synthase complex

A protein complex that possesses fatty-acyl-CoA synthase activity.


BORC complex

A protein complex that is involved in positioning of the lysosome within the cytoplasm and which is composed of BLOC1S1, BLOC1S2, BORCS5, BORCS6, BORCS7, BORCS8, KXD1 and SNAPIN. The BORC complex recruits ARL8 at the cytosolic face of lysosomes and couples them to microtubule plus-end-directed kinesin motors.


B800-850 antenna complex

Protein-pigment complex that absorbs light at 800 and 850 nm; is peripherally associated to the bacterial reaction center; transfers excitation energy to the B875 antenna complex.


exoribonuclease complex

A protein complex which is capable of exoribonuclease activity.


glycine-tRNA ligase complex

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


7SK snRNP

A ribonucleoprotein complex that contains the 7SK snRNA. The 7SK snRNP plays a central role in RNA polymerase II elongation control by regulating the availability of active P-TEFb.


TRAMP complex

A multiprotein complex having distributive polyadenylation activity of a variety of RNA substrates including hypomodified and incorrectly folded tRNAs, pre-snRNAs, pre-snoRNAs, incorrectly spliced or processed pre-mRNAs, cryptic unstable transcripts (CUTs), pre-rRNAs and rRNA fragments released as part of rRNA processing. In S. cerevisiae, the complex consists of either Pap2 (also known as Trf4) or Trf5, Air1 or Air2, and Mtr4, and is involved in RNA 3'-end processing and in RNA surveillance and quality control.


fumarate reductase complex

A membrane-bound flavoenzyme complex consisting of four subunits, A, B, C, and D. A and B comprise the membrane-extrinsic catalytic domain and C (InterPro:IPR003510; InterPro:IPR004224) and D (InterPro:IPR003418) link the catalytic centers to the electron-transport chain. This family consists of the 13 kDa hydrophobic subunit D. This component may be required to anchor the catalytic components of the fumarate reductase complex to the cytoplasmic membrane. Fumarate reductase couples the reduction of fumarate to succinate to the oxidation of quinol to quinone, in a reaction opposite to that catalyzed by the related complex II of the respiratory chain (succinate dehydrogenase-(ubiquinone)).


Pip2-Oaf1 complex

A heterodimeric complex consisting of Zn(2)Cys(6) containing transcription factors Pip2 and Oaf1. It binds to the oleate response element (ORE), found in the promoters of fatty acid-inducible genes in Saccharomyces where, in the presence of oleate this bound complex activates the transcription of genes encoding peroxisomal proteins.


RasGAP-Fyn-Lyn-Yes complex

A protein complex that consists of a GTPase activator protein (GAP) for Ras and three Src family protein tyrosine kinases, Fyn, Lyn and Yes. The complex is involved in signaling upon platelet activation.


RISC complex

A ribonucleoprotein complex that contains members of the Argonaute family of proteins, small interfering RNAs (siRNAs) or microRNAs (miRNAs), and miRNA or siRNA-complementary mRNAs, in addition to a number of accessory factors. The RISC complex is involved in posttranscriptional repression of gene expression through downregulation of translation or induction of mRNA degradation.


A protein complex that consists of an alphaV-beta6 integrin complex bound to osteopontin.


GATOR1 complex

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


alpha-beta T cell receptor complex

A T cell receptor complex in which the TCR heterodimer comprises alpha and beta chains, associated with the CD3 complex; recognizes a complex consisting of an antigen-derived peptide bound to a class I or class II MHC protein.


E.F.G complex

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


nuclear pore linkers

A substructure of the nuclear pore complex (NPC) that serves to connect members of the central transport channel (composed of FG-nucleoporins) to the core scaffold (composed of the inner and outer NPC rings). In S. cerevisiae, the linkers are Nic96p and Nup82p. In vertebrates, they are Nup93 and Nup88. Components are arranged in 8-fold symmetrical 'spokes' around the central transport channel. Both linkers can be isolated in association with specific FG-nucleoporins, complexes that are sometimes referred to as the Nic96 complex (Nic96p-Nsp1p-Nup49p-Nup57p) and the Nup82 complex (Nup82p-Nup116p-Nup159p-Gle2p).


RNA polymerase I transcription regulator complex

A transcription factor complex that acts at a regulatory region of a gene transcribed by RNA polymerase I.


APC-IQGAP1-CLIP-170 complex

A protein complex that contains the tumor suppressor protein adenomatous polyposis coli (APC), the small GTPase Cdc42, and CLIP-170; may play a role in cytoskeleton organization and cell migration.


clathrin coat

A membrane coat found on coated pits and some coated vesicles; consists of polymerized clathrin triskelions, each comprising three clathrin heavy chains and three clathrin light chains, linked to the membrane via one of the AP adaptor complexes.


type IV site-specific deoxyribonuclease complex

A complex consisting of two proteins which acts as an endonuclease in DNA sequences containing a specific modified recognition site. Modifications may include methylation, hydroxymethylation, and glucosyl-hydroxymethylation.


collagen type XIV trimer

A collagen homotrimer of alpha1(XIV) chains; type XIV collagen triple helices may link sheet-forming or fibrillar collagens to other structures.


heavy chain immunoglobulin complex

A protein complex composed of two identical immunoglobulin heavy chains of the IgNAR isotype held together by disulfide bonds and lacking immunoglobulin light chains.


alpha5-beta1 integrin-tissue transglutaminase complex

A protein complex that consists of an alpha5-beta1 integrin complex bound to tissue transglutaminase.


ASAP complex

A protein complex involved in regulation of mRNA processing and apoptosis. It binds to RNA in a sequence-independent manner and is recruited to the EJC prior to or during the splicing process. In humans the core proteins are RNPS1, SAP18 and ACIN1.


alpha6-beta4 integrin-CD151 complex

A protein complex that consists of an alpha6-beta4 integrin complex bound to the tetraspanin CD151.


IgD B cell receptor complex

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


replication inhibiting complex

A protein complex that inhibits multiple events of replication initiation during one replication cycle.


polyketide synthase complex

A protein complex that carries out enzymatic reactions involved in the biosynthesis of polyketides, any of a diverse group of natural products synthesized via linear poly-beta-ketones.


interleukin-12 receptor complex

A protein complex that binds interleukin-12 and that consists of, at a minimum, a dimeric interleukin and its two receptor subunits as well as optional additional kinase subunits.


Grb2-SHP-2 complex

A protein complex that contains the receptor adaptor proteins Grb2 and SHP-2, and is involved signaling via the PDGFR signaling pathway.


CFTR-NHERF-ezrin complex

A protein complex that contains ezrin, Na+/H+ exchanger regulatory factor (NHERF, also called EBP50), and two copies of the cystic fibrosis transmembrane conductance regulator (CFTR). The CFTR molecules interact with NHERF via their cytoplasmic tail domains; the complex is thought to link the CFTR channel to the actin cytoskeleton and contribute to the regulation of channel activity.


eNoSc complex

A chromatin silencing complex that recruits histone-modifying enzymes and upregulates silencing of rDNA in response to glucose starvation.


Mre11 complex

Trimeric protein complex that possesses endonuclease activity; involved in meiotic recombination, DNA repair and checkpoint signaling. In Saccharomyces cerevisiae, the complex comprises Mre11p, Rad50p, and Xrs2p; complexes identified in other species generally contain proteins orthologous to the Saccharomyces cerevisiae proteins.


CSK-GAP-A.p62 complex

A protein complex that contains the protein-tyrosine kinase CSK and the GTPase-activating protein (GAP)-associated p62 (GAP-A.p62); may mediate translocation of proteins, including GAP and CSK, to membrane or cytoskeletal regions upon c-Src activation.


cytosolic tricarboxylic acid cycle enzyme complex

Any of the heteromeric enzymes, located in the cytosol, that act in the tricarboxylic acid (TCA) cycle.


NLRP6 inflammasome complex

An inflammasome complex that consists of NLRP6, PYCARD/ASC and caspase-1 or caspase-4/caspase-11.


Smc5-Smc6 complex

A conserved complex that contains a heterodimer of SMC proteins (Smc5p and Smc6p, or homologs thereof) and several other proteins, and is involved in DNA repair and maintaining cell cycle arrest following DNA damage. In S. cerevisiae, this is an octameric complex called Mms21-Smc5-Smc6 complex, with at least five of its subunits conserved in fission yeast and humans.


Sodium:potassium-exchanging ATPases are tetrameric proteins, consisting of two large alpha subunits and two smaller beta subunits. The alpha subunits bear the active site and penetrate the membrane, while the beta subunits carry oligosaccharide groups and face the cell exterior.


cortical Lewy body

Cytoplasmic inclusion similar to a classical Lewy body but lacking a halo of protein fibrils.


inclusion body

A discrete intracellular part formed of aggregated molecules such as proteins or other biopolymers.


nucleolar peripheral inclusion body

Inclusion bodies located at the nucleolar periphery where several nuclear factors are reversibly aggregated and sequestered during acute heat stress or starvation.


classical Lewy body

Cytoplasmic inclusion, 5 to 15 micrometers in diameter, with a dense core surrounded by a halo of 10 to 20 nm wide radially oriented alpha-synuclein fibrils.


nematosome

Cytoplasmic, ball-like inclusion resembling a nucleolus and consisting of a convoluted network of electron-opaque strands embedded in a less dense matrix. It measures approximately 0.9 microns and lacks a limiting membrane. Its strands (diameter = 400-600 A) appear to be made of an entanglement of tightly packed filaments and particles approximately 25-50 A thick. Cytochemical studies suggest the presence of nonhistone proteins and some RNA. Usually only one such structure is present in a cell, and it appears to occur in most ganglion cells. Although they can be seen anywhere in the cell body, nematosomes are typically located in the perinuclear cytoplasm, where they are often associated with smooth-surfaced and coated vesicles.


skein-like inclusion

Intracytoplasmic filamentous structure frequently encountered in preparations immunostained for ubiquitin.


aggresome

An inclusion body formed by dynein-dependent retrograde transport of an aggregated protein on microtubules.


fibrillary inclusion

Cellular inclusion consisting of circular areas filled with fine slender filaments about 10 nanometers in diameter, delimited by a wall of varying complexity (either a single continuous membrane or a tubular network consisting of a fine filamentous material giving the wall a honeycomb appearance). Fibrillary inclusions are found in the cytoplasm of giant cells of Dieters in the lateral vestibular nucleus of the rat; similar structures have been described in the ventral cochlear nucleus, spinal cord, and substantia nigra.


neurofibrillary tangle

Intracellular mass of paired, helically wound protein filaments (also called PHF) lying in the cytoplasm of neuronal cell bodies and neuritic cell processes. Neurofibrillary tangles contain an abnormally phosphorylated form of a microtubule-associated protein, tau. The shape of these inclusions may resemble a flame or a star.


nuclear inclusion body

An intranuclear focus at which aggregated proteins have been sequestered.


glial cytoplasmic inclusion

Non-membrane-bound cytoplasmic inclusions composed of 10-40 nm granule-coated fibrils. These inclusions have an abnormal accumulation of alpha-synuclein protein and are found in association with multiple system atrophy.


Lewy body

Cytoplasmic, spherical inclusion commonly found in damaged neurons, and composed of abnormally phosphorylated, neurofilament proteins aggregated with ubiquitin and alpha-synuclein.


complex laminated body

A cytoplasmic inclusion body found in some lateral geniculate neurons and composed of sheets of tubules (25 nm in diameter) separated by dense material (about 75 nm wide), which together with the tubules whorl give a structure resembling a fingerprint.


laminated body

Inclusion body characterized by regularly spaced sheets of tubules arranged in a whorl pattern resembling a fingerprint. Laminated bodies have been observed in neurons of the lateral geniculate nucleus.


Pick body

Cellular inclusion composed of numerous tau fibrils arranged in a disorderly array. Tau protein is a major component, though Pick bodies also contain ubiquitin, alpha-synuclein, and apolipoprotein E.


hyaline inclusion

A glass-like, pale intracellular inclusion.


fibrillar center

A structure found most metazoan nucleoli, but not usually found in lower eukaryotes; surrounded by the dense fibrillar component; the zone of transcription from multiple copies of the pre-rRNA genes is in the border region between these two structures.


cnida

A giant secretory organelle that comprises a bulb-shape capsule containing a coiled hollow tubule structure attached to it. A cnida defines the phylum Cnidaria.


glutamatergic postsynaptic density

The post-synaptic specialization of a glutamatergic excitatory synapse.


presynaptic active zone membrane

The membrane portion of the presynaptic active zone; it is the site where docking and fusion of synaptic vesicles occurs for the release of neurotransmitters.


central plaque of mitotic spindle pole body

One of three laminate structures that form the mitotic spindle pole body; the inner plaque is on the nuclear face of the spindle pole body.


central plaque of spindle pole body

One of three laminate structures that form the spindle pole body; the central plaque is embedded in the nuclear envelope.


central region of growth cone

The center of the migrating motile tip of a growing nerve cell axon or dendrite.


cellular bud neck contractile ring

A contractile ring, i.e. a cytoskeletal structure composed of actin filaments and myosin, that forms beneath the plasma membrane at the mother-bud neck in mitotic cells that divide by budding in preparation for completing cytokinesis. An example of this structure is found in Saccharomyces cerevisiae.


extrahaustorial matrix

The space between the symbiont plasma membrane and the extrahaustorial membrane of the host.


glyoxysomal membrane

The lipid bilayer surrounding a glyoxysome.


glycosome membrane

The lipid bilayer surrounding a glycosome.


nucleus lagging edge

The area of a motile nucleus furthest from the direction of movement.


bleb

A cell extension caused by localized decoupling of the cytoskeleton from the plasma membrane and characterized by rapid formation, rounded shape, and scarcity of organelles within the protrusion. Blebs are formed during apoptosis and other cellular processes, including cell locomotion, cell division, and as a result of physical or chemical stresses.


mannosome

A specialised tubular organelle, assembled in hexagonal bundles within an external membrane. Mannosomes are specific to molluscs and are thought to be involved in a general stress reaction.


ribbon synapse

Type of synapse characterized by an electron-dense ribbon, lamella (bar) or spherical body in the presynaptic process cytoplasm.


photoreceptor ribbon synapse

A ribbon synapse between a retinal photoreceptor cell (rod or cone) and a retinal bipolar cell. These contain a plate-like synaptic ribbon.


cochlear hair cell ribbon synapse

A ribbon synpase of an auditory hair cell of the cochlear. These ribbon synapses contain spherical synaptic ribbons and lack and arciform density.


extrinsic component of postsynaptic membrane

The component of the postsynaptic membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of presynaptic membrane

The component of the presynaptic membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of presynaptic endocytic zone membrane

The component of the presynaptic endocytic zone membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of postsynaptic specialization membrane

The component of the postsynaptic specialization membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of postsynaptic density membrane

The component of the postsynaptic density membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of external side of plasma membrane

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


extrinsic component of presynaptic active zone membrane

The component of the presynaptic active zone membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of synaptic membrane

The component of the synaptic membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of postsynaptic endocytic zone

The component of the postsynaptic endocytic zone membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


bacterial microcompartment

An organelle found in bacteria consisting of a proteinaceous coat containing metabolic enzymes whose purpose is the sequestration or concentration of metabolites and which has the appearance of a polygonal granule by electron microscopy.


perinucleolar chromocenter

A chromocenter adjacent to the nucleolus.


meiotic spindle

A spindle that forms as part of meiosis. Several proteins, such as budding yeast Spo21p, fission yeast Spo2 and Spo13, and C. elegans mei-1, localize specifically to the meiotic spindle and are absent from the mitotic spindle.


mitochondrial nucleoid

The region of a mitochondrion to which the DNA is confined.


protein aggregate center

Reversible aggregate of misfolded proteins and chaperones formed to shield thermosensitive proteins from degradation until conditions allow disaggregation and refolding.


crystalloid

A transient, cytoplasmic organelle found in Plasmodium species that resembles a cytoplasmic inclusion body and whose function is poorly understood. Crystalloids form in ookinetes and disappear after ookinete-to-oocyst transformation.


arciform density

An electron dense structure that anchors a synaptic ribbon to the presynaptic membrane.


monolayer-surrounded lipid storage body

A subcellular organelle of plant cells surrounded by 'half-unit' or a monolayer membrane instead of the more usual bilayer. The storage body has a droplet of triglyceride surrounded by a monolayer of phospholipids, interacting with the triglycerides and the hydrophilic head groups facing the cytosol, and containing major protein components called oleosins.


mitochondrial chromosome

A chromosome found in the mitochondrion of a eukaryotic cell.


Z chromosome

The sex chromosome present in both sexes of species in which the female is the heterogametic sex. Two copies of the Z chromosome are present in each somatic cell of males and one copy is present in females.


spectrosome

A germline specific spherical organelle, rich in membrane skeletal proteins. Precursor to the fusome.


sex chromosome

A chromosome involved in sex determination.


ascus lipid droplet

Any particle of coalesced lipids in an ascus or ascospore. May include associated proteins.


Barr body

A structure found in a female mammalian cell containing an unpaired X chromosome that has become densely heterochromatic, silenced and localized at the nuclear periphery.


chloroplast nucleoid

The region of a chloroplast to which the DNA is confined.


chloroplast stromal thylakoid

Unstacked thylakoids that connect the grana stacks through the stroma.


plastid ribosome

A ribosome contained within a plastid.


XY body

A structure found in a male mammalian spermatocyte containing an unpaired X chromosome that has become densely heterochromatic, silenced and localized at the nuclear periphery.


pyrenoid

A non-membrane-bounded organelle found within the chloroplasts of algae and hornworts; responsible for carbon dioxide fixation.


carboxysome

An organelle consisting of a proteinaceous coat and enzymes for the fixation of CO2. It augments the concentration of CO2 in the vicinity of RuBisCO to increase the efficiency of CO2 fixation under atmospheric conditions.


bacterial nucleoid

The region of a bacterial cell to which the DNA is confined.


goblet cell theca

A cup shaped specialization of the cytoskeleton that forms a thin layer located just below the apical mass of mature mucin secretory granules in the cytoplasm of goblet cells of the intestinal epithelium. It consists of an orderly network of intermediate filaments and microtubules. Microtubules are arranged vertically, like barrel staves, along the inner aspect of the theta. Intermediate filaments form two networks: an inner, basketlike network and an outer series of circumferential bundles resembling the hoops of a barrel.


synaptic ribbon

A non-membrane bound, electron dense structure associated that extends perpendicular to the presynaptic membrane in ribbon synapses. The ribbon's surface is studded with small particles to which synaptic vesicles tether via fine filaments. The tethered vesicles function as a pool, several fold greater than the docked pool available for fast release, which supports sustained release of vesicles. Synaptic ribbons may be plate like or spherical.


proplastid nucleoid

The region of a proplastid to which the DNA is confined.


Y chromosome

The sex chromosome present in males of species in which the male is the heterogametic sex; generally, the sex chromosome that pairs with the X chromosome in the heterogametic sex. The Y chromosome is absent from the cells of females and present in one copy in the somatic cells of males.


chloroplast thylakoid

Sac-like membranous structures (cisternae) in a chloroplast combined into stacks (grana) and present singly in the stroma (stroma thylakoids or frets) as interconnections between grana. An example of this component is found in Arabidopsis thaliana.


active sex chromosome

A sex chromosome that has not been inactivated.


polytene chromosome chromocenter

A region at which the centric regions of polytene chromosomes are joined together.


cyanelle thylakoid

A thylakoid found in a cyanelle, which is a type of plastid found in certain algae. The cyanelle contains a photosynthetic membrane resembling that of cyanobacteria.


prothylakoid

Underdeveloped thylakoids found in etioplasts, lacking competent photosynthetic membranes. Rapidly develop into mature thylakoids in the presence of light.


bacterial thylakoid

A thylakoid that is derived from and attached to, but not necessarily continuous with, the plasma membrane, and is not enclosed in a plastid. It bears the photosynthetic pigments in photosynthetic cyanobacteria.


gas vesicle

An intracellular non-membrane-bounded organelle; a hollow structure made of protein, which usually has the form of a cylindrical tube closed by conical end caps. By regulating their relative gas vesicle content, aquatic microbes are able to perform vertical migrations.


nucleolus-like body

A nuclear compartment containing significant amounts of non-nucleolar, spliceosomal components. It is commonly found in germinal vesicle (GV) stage oocytes, and is similar to both nucleoli and sphere organelles.


dynein axonemal particle

An aggregation of axonemal dyneins, their specific assembly factors, and broadly-acting chaperones that is located in the cytoplasm.


autosome

Any chromosome other than a sex chromosome.


thylakoid

A membranous cellular structure that bears the photosynthetic pigments in plants, algae, and cyanobacteria. In cyanobacteria thylakoids are of various shapes and are attached to, or continuous with, the plasma membrane. In eukaryotes they are flattened, membrane-bounded disk-like structures located in the chloroplasts; in the chloroplasts of higher plants the thylakoids form dense stacks called grana. Isolated thylakoid preparations can carry out photosynthetic electron transport and the associated phosphorylation.


organellar chromatophore thylakoid

A thylakoid located in an organellar chromatophore.


plastid thylakoid

Any thylakoid within a plastid.


plastid nucleoid

The region of a plastid to which the DNA is confined.


propanediol degradation polyhedral organelle

An organelle found in bacteria consisting of a proteinaceous coat containing enzymes for the degradation of 1,2-propanediol whose purpose is the protection of the rest of the cell from the toxic propionaldehyde product of the enzyme diol dehydratase.


chlorosome

A large enclosure of aggregated pigment, typically bacteriochlorophyll c (BChl c), that acts as a light-harvesting antenna structure and is characteristic of green photosynthetic bacteria (e.g. Chlorobiaceae). The BChl aggregates are organized into lamellar elements by pigment-pigment rather than pigment-protein interactions. Chlorosomes also contain BChl a, carotenoids, quinones, lipids, and proteins, and are attached to the cytoplasmic membrane via a BChl a-containing protein baseplate.


ventral disc

Specialized organelle found in Giardia species (trophozoite stage) and characterized by a spiral array of microtubules and microtubule-associated structures including dorsal microribbons and crossbridges. The edge of the ventral disc narrows into a lateral crest. The ventral disk mediates mechanical attachment of the trophozoite to the host's intestinal wall, and contains the contractile proteins actinin, alpha-actinin, myosin, and tropomyosin working towards contraction of the disk involved in adherence.


nematocyst

An organelle found in cnidoblast (nematoblast) cells. When matured, these stinging organelles store toxins and can deliver them when the cnidocil (a short extension of the cnidocyst) is stimulated by a prey or another stimulus.


W chromosome

The sex chromosome present in females of species in which the female is the heterogametic sex; generally, the sex chromosome that pairs with the Z chromosome in the heterogametic sex. The W chromosome is absent from the cells of males and present in one copy in the somatic cells of females.


inactive sex chromosome

A sex chromosome that has been inactivated.


X chromosome

The sex chromosome present in both sexes of species in which the male is the heterogametic sex. Two copies of the X chromosome are present in each somatic cell of females and one copy is present in males.


blepharoplast

An intracellular non-membrane-bounded organelle found in multi-ciliated sperm cells of some primitive land plants, and consisting of many radially arranged ninefold symmetric cylinders. The blepharoplast is involved in de novo formation of multiple centrioles; it enlarges and then disintegrates into many procentrioles, which elongate and ultimately nucleate cilia on the surface of the sperm cell.


polytene chromosome

A type of chromosome in a polyploid cell, formed when multiple copies of homologous chromosomes are aligned side by side to give a giant chromosome in which distinct chromosome bands are readily visible.


granal stacked thylakoid

Appressed thylakoid membranes that are part of a granum (stacked regions). A characteristic of these appressed regions is the preferential localization of photosystem II.


chromocenter

A region in which centric, heterochromatic portions from more than one chromosomes form a compact structure.


podosome

An actin-rich adhesion structure characterized by formation upon cell substrate contact and localization at the substrate-attached part of the cell, contain an F-actin-rich core surrounded by a ring structure containing proteins such as vinculin and talin, and have a diameter of 0.5 mm.


proteasome storage granule

An aggregation of proteasome core protease (CP) and regulatory particle (RP) complexes that localizes in the cytoplasm as dot-like structures when cells are in a quiescent state.


elaioplast

A leucoplast in which oil is stored.


histone locus body

A nuclear body associated with the histone gene locus that is thought to contain all of the factors necessary for histone mRNA transcription and pre-mRNA processing. In Drosophila, U7 snRNP is located in the histone locus body rather than the distinct Cajal body.


mitotic nuclear bridge

A narrow constricted region of the nucleus that forms around the anaphase spindle during closed mitosis, and connects the main portions of the newly forming daughter nuclei.


host cell rough endoplasmic reticulum

The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host rough ER has ribosomes adhering to the outer surface.


autophagosome membrane

The lipid bilayer surrounding an autophagosome, a double-membrane-bounded vesicle in which endogenous cellular material is sequestered.


amphisome membrane

Any membrane that is part of an amphisome.


extrinsic component of external side of mycolate outer membrane

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


extrinsic component of mycolate outer membrane

The component of mycolate outer membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


alae of collagen and cuticulin-based cuticle extracellular matrix

Raised, thickened cuticular ridges that run longitudinally, and in parallel, along the left and right sides of the animal. The alae lie above the hypodermal cells known as the lateral seam cells. In C. elegans, alae are produced in L1 larvae, dauer larvae and adult stage animals, where they consist of three, five, and three ridges of distinct morphology, respectively.


host multivesicular body

A late endosome in which regions of the limiting host cell endosomal membrane invaginate to form internal vesicles; host membrane proteins that enter the internal vesicles are sequestered from the host cytoplasm.


host cell late endosome

A prelysosomal endocytic organelle differentiated from host early endosomes by lower lumenal pH and different protein composition. Host late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center.


polar tube

A highly specialized structure unique to microsporidia that is required for host cell invasion. In the spore, the polar tube is connected at the anterior end, and then coils around the sporoplasm. Upon appropriate environmental stimulation, the polar tube rapidly discharges out of the spore, pierces a cell membrane and serves as a conduit for sporoplasm passage into the new host cell.


endospore coat

The layer in a bacterial endospore that lies under the exosporium, and is impermeable to many toxic molecules. The coat may also contain enzymes that are involved in endospore germination.


Yb body

A cytoplasmic part that appears as an electron-dense sphere of around 1.5 micron diameter containing Yb protein found in somatic cells of ovary and testis. There are one to two Yb bodies per cell.


leucoplast stroma

The space enclosed by the double membrane of a leucoplast.


linear element

A proteinaceous scaffold associated with fission yeast chromosomes during meiotic prophase. Linear elements consist of a protein complex, LinE, with four main structural components (Rec10, Rec25, Rec27, and Mug20 in S. pombe) associated with chromatin. The resulting structure is related to but not equivalent to the synaptonemal complex.


amyloplast inner membrane

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


perisynaptic space

The extracellular region immediately adjacent to to a synapse.


megagametophyte egg cell nucleus

The nucleus of a plant egg cell. This nucleus is found at the micropylar end of the embryo.


lignin network

An extracellular matrix part that consists of lignin in the form of a three-dimensional polymeric network. Lignins are complex racemic aromatic heteropolymers derived from a variety of phenylpropane monomers coupled together by an assortment of carbon-carbon and ether linkages. Lignin is crucial for structural integrity of the cell wall and stiffness and strength of the stem. In addition, lignin waterproofs the cell wall, enabling transport of water and solutes through the vascular system, and plays a role in protecting plants against pathogens.


hyphal septin band

A septin band, i.e. a diffuse ring composed of a series of septin bars running parallel to the long axis of the cell, located at the junction between the mother cell and the germ tube (hypha) of a fungal cell growing filamentously.


pilus shaft

The long, slender, mid section of a pilus.


lower tip-link density

An electron-dense plaque at the lower end of a stereocilia tip link that provides the anchor in the stereocilia membrane at the tip of the stereocilium from which the tip link rises.


sieve area

A pit-like area in the cell wall of a sieve element; contains pores lined with callose and occupied by strands of protoplasmic material that interconnect the protoplasts of contiguous sieve elements.


host cell PML body

A nuclear body that reacts against SP100 auto-antibodies (PML = promyelocytic leukemia) located within a cell of a host organism.


nucleoplasmic side of nuclear pore

The side of the nuclear pore complex (NPC) that faces the nucleoplasm.


autolysosome

A type of secondary lysosome in which a primary lysosome has fused with the outer membrane of an autophagosome. It is involved in the second step of autophagy in which it degrades contents with acidic lysosomal hydrolases.


secondary lysosome

Vacuole formed by the fusion of a lysosome with an organelle (autosome) or with a primary phagosome.


left lateral basal body pair

Set of two basal bodies found in Giardia species (trophozoite stage). It comprises the anterior and ventral basal bodies located to the right of the left nucleus of the trophozoite when viewed dorsally.


host cell centrosome

A structure in a host cell comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.


stereocilia tip link

A stereocilia link that is formed by a fine filament running more or less vertically upward from the tip of each shorter stereocilium to attach at a higher point on its adjacent taller neighbor. Tilting the bundle puts tension on the filaments, which pull on mechanically gated ion channels in the membrane of the stereocilia.


axonemal outer doublet

Part of an axoneme consisting in a doublet microtubule. Nine of these outer doublets form the 9+0 axoneme, while the 9+2 axoneme also contains a central pair. Dynein arms attached to the doublets provide the mechanism of movement of the cilium.


thorny excrescence

Large complex spine protruding from a dendrite. Each excrescence is formed by a cluster of spine heads.


postsynapse of neuromuscular junction

The postsynapse of a neuromuscular junction. In vertebrate muscles this includes the motor end-plate, consisting of postjunctional folds of the sarcolemma.


dinoflagellate sulcus

A cell surface furrow that occurs on the ventral side of a dinoflagellate cell. It partially houses the longitudinal flagellum. The sulcus intersects with the cingulum on the ventral side of a dinoflagellate cell.


cell surface furrow

A furrow that may be found on the cell surface. Examples include the cingulum and sulcus found in some dinoflagellates.


dinoflagellate cingulum

A cell surface furrow that wraps around a dinoflagellate cell; the transverse flagellum lies in it.


dinoflagellate sulcal notch

A dinoflagellate sulcus that extends all the way to the posterior end of the cell (also known as antapex). The presence of a sulcal notch makes the dinoflagellate hypocone appear bilobed.


dinoflagellate apical groove

A cell surface furrow (or groove) found on a dinoflagellate apex. It typically loops around the apex.


attachment organelle membrane

The lipid bilayer surrounding an attachment organelle. This is a region of the cell membrane facing the environment - in mycoplasma, part of the mycolate outer membrane.


host cell filopodium

Thin, stiff protrusion extended by the leading edge of a motile host cell such as a crawling fibroblast or amoeba, or an axonal growth cone; usually approximately 0.1 um wide, 5-10 um long, can be up to 50 um long in axon growth cones; contains a loose bundle of about 20 actin filaments oriented with their plus ends pointing outward.


host cell projection

A prolongation or process extending from a host cell, e.g. a flagellum or axon.


host cell uropod

A host cell membrane projection with related cytoskeletal components at the trailing edge of a cell in the process of migrating or being activated, found on the opposite side of the cell from the leading edge or immunological synapse, respectively.


microtubule minus-end

The end of a microtubule that does not preferentially grow (polymerize).


microtubule end

Any end of a microtubule. Microtubule ends differ in that the so-called microtubule plus-end is the one that preferentially grows by polymerization, with respect to the minus-end.


post-anaphase array microtubule end

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


mitotic spindle astral microtubule end

Any microtubule end that is part of a mitotic spindle astral microtubule.


cytoplasmic microtubule minus-end

A microtubule minus end that is part of a cytoplasmic microtubule.


plasmodesmatal endoplasmic reticulum

Endoplasmic reticulum found in plasmodesmata, junctions connecting the cytoplasm of adjacent plant cells.


smooth endoplasmic reticulum

The smooth endoplasmic reticulum (smooth ER or SER) has no ribosomes attached to it. The smooth ER is the recipient of the proteins synthesized in the rough ER. Those proteins to be exported are passed to the Golgi complex, the resident proteins are returned to the rough ER and the lysosomal proteins after phosphorylation of their mannose residues are passed to the lysosomes. Glycosylation of the glycoproteins also continues. The smooth ER is the site of synthesis of lipids, including the phospholipids. The membranes of the smooth ER also contain enzymes that catalyze a series of reactions to detoxify both lipid-soluble drugs and harmful products of metabolism. Large quantities of certain compounds such as phenobarbital cause an increase in the amount of the smooth ER.


membrane stack

A configuration of endoplasmic reticulum (ER) found in Purkinje cells in the cerebellum and in axons in the lateral vestibular nucleus, consisting of parallel and interconnecting tubules whose outer surfaces are covered by particles or ringlike structures.


interphase microtubule organizing center

A microtubule organizing center found in interphase cells, which organize a longitudinal array of three to five MT bundles from the nuclear envelope during interphase. Each MT bundle is composed of two to seven MTs arranged in an antiparallel configuration, with the dynamic MT plus ends extending toward the cell tips and stable minus ends near the nucleus.


host intracellular part

Any constituent part of the living contents of a host cell; the matter contained within (but not including) the plasma membrane, usually taken to exclude large vacuoles and masses of secretory or ingested material. In eukaryotes it includes the nucleus and cytoplasm. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host chromosome

A structure composed of a very long molecule of DNA and associated proteins (e.g. histones) that carries hereditary information, occurring within a host cell.


host cell nucleus

A membrane-bounded organelle as it is found in the host cell in which chromosomes are housed and replicated. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell synaptic vesicle

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


Maurer's cleft

A disk-like structure that appears at the periphery of a red blood cell infected by an apicomplexan parasite, characterized by a translucent lumen and an electron-dense coat of variable thickness; often appears to be tethered to the host cell membrane by fibrous connections with the erythrocyte cytoskeleton.


viral replication complex

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


host cell nucleolus

A small, dense body one or more of which are present in the nucleus of eukaryotic host cells.


host cell mitochondrial intermembrane space

The region between the inner and outer lipid bilayers of the host cell mitochondrial envelope.


host cell plastid

Any member of a family of organelles as found in the cytoplasm of host cells, which are membrane-bounded and contain DNA. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell nucleoplasm

That part of a host cell's nuclear content other than the chromosomes or the nucleolus. The host is the larger of the organisms involved in a symbiotic interaction.


host symbiosome

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


host cell endoplasmic reticulum lumen

The volume enclosed by the membranes of the host cell endoplasmic reticulum.


host cell synaptic vesicle membrane

The lipid bilayer surrounding a host synaptic vesicle.


host cell nuclear lamina

The fibrous, electron-dense layer lying on the nucleoplasmic side of the inner membrane of a host cell nucleus, composed of lamin filaments.


host cell peroxisome

A small host cell organelle enclosed by a single membrane, and found in most eukaryotic cells. Contains peroxidases and other enzymes involved in a variety of metabolic processes including free radical detoxification, lipid catabolism and biosynthesis, and hydrogen peroxide metabolism.


host cell endosome lumen

The volume enclosed by the membranes of the host cell endosome.


host cell mitochondrion

A semiautonomous, self replicating organelle as found in host cells that occurs in varying numbers, shapes, and sizes in the cell cytoplasm. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell perinuclear region of cytoplasm

The host cell cytoplasm situated near, or occurring around, the host nucleus.


host thylakoid membrane

The pigmented membrane of any host thylakoid.


host cell cytoplasmic vesicle

A vesicle formed of membrane or protein, found in the cytoplasm of a host cell.


host cell lysosome

A small lytic vacuole that has cell cycle-independent morphology and is found in most host animal cells and that contains a variety of hydrolases, most of which have their maximal activities in the pH range 5-6. The contained enzymes display latency if properly isolated. About 40 different lysosomal hydrolases are known and host cell lysosomes have a great variety of morphologies and functions.


host cell nuclear part

Any constituent part of a host cell's nucleus, a membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. The host is the larger of the organisms involved in a symbiotic interaction.


host cell lipid droplet

Any particle of coalesced lipids in the cytoplasm of a host cell. May include associated proteins.


host cell Cajal body

A class of nuclear body in the eukaryotic host cell, first seen after silver staining by Ramon y Cajal in 1903, enriched in small nuclear ribonucleoproteins, and certain general RNA polymerase II transcription factors; ultrastructurally, they appear as a tangle of coiled, electron-dense threads roughly 0.5 micrometers in diameter; involved in aspects of snRNP biogenesis; the protein coilin serves as a marker for Cajal bodies. Some argue that Cajal bodies are the sites for preassembly of transcriptosomes, unitary particles involved in transcription and processing of RNA. The host is the larger of the organisms involved in a symbiotic interaction.


host intracellular organelle

Organized structure of distinctive morphology and function, occurring within the host cell. Includes the nucleus, mitochondria, plastids, vacuoles, vesicles, ribosomes and the cytoskeleton. Excludes the plasma membrane. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell smooth endoplasmic reticulum

The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host smooth ER has no ribosomes adhering to the outer surface.


host cell mitochondrial envelope

The double lipid bilayer enclosing the host cell mitochondrion and separating its contents from the host cell cytoplasm; includes the intermembrane space.


symbiont-containing vacuole

Membrane-bounded vacuole within a host cell in which a symbiont organism resides. The vacuole membrane is derived from both the host and symbiont.


host cytoskeleton

A cellular structure that forms the internal framework of eukaryotic and prokaryotic host cells. The cytoskeleton includes intermediate filaments, microfilaments, microtubules, the microtrabecular lattice, and other structures characterized by a polymeric filamentous nature and long-range order within the cell. The various elements of the cytoskeleton not only serve in the maintenance of cellular shape but also have roles in other cellular functions, including cellular movement, cell division, endocytosis, and movement of organelles.


host cell cytoplasmic vesicle membrane

The lipid bilayer surrounding a host cell cytoplasmic vesicle.


host cell endosome

A membrane-bounded organelle that carries materials newly ingested by endocytosis. It passes many of the materials to host cell lysosomes for degradation.


host cell nuclear matrix

The dense fibrillar network lying on the inner side of the host nuclear membrane.


double membrane vesicle viral factory lumen

The volume surrounded by the inner membrane of a double membrane vesicle viral factory.


host cell cytoplasm part

Any constituent part of the host cell cytoplasm, all of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell endoplasmic reticulum

The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host ER takes two forms, rough (or granular), with ribosomes adhering to the outer surface, and smooth (with no ribosomes attached).


host cell cytosol

The part of the host cell cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.


host cell viral nucleoid

The region of a host cell that contains the viral genome.


host intracellular membrane-bounded organelle

Organized structure of distinctive morphology and function, as found in host cells, bounded by a single or double lipid bilayer membrane and occurring within the cell. Includes the nucleus, mitochondria, plastids, vacuoles, and vesicles. Excludes the plasma membrane. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host thylakoid

A membranous cellular structure within the host cell that bears the photosynthetic pigments in plants, algae, and cyanobacteria. In cyanobacteria thylakoids are of various shapes and are attached to, or continuous with, the host plasma membrane. In eukaryotic host cells they are flattened, membrane-bounded disk-like structures located in the chloroplasts; in the chloroplasts of higher plants the thylakoids form dense stacks called grana. Isolated thylakoid preparations can carry out photosynthetic electron transport and the associated phosphorylation.


postsynaptic specialization membrane

The membrane component of the postsynaptic specialization. This is the region of the postsynaptic membrane in which the population of neurotransmitter receptors involved in synaptic transmission are concentrated.


postsynaptic specialization membrane of symmetric synapse

The membrane component of the postsynaptic specialization of a symmetic synapse. This is the region of the postsynaptic membrane in which the population of neurotransmitter receptors involved in synaptic transmission are concentrated.


nucleoid

The region of a virus, bacterial cell, mitochondrion or chloroplast to which the nucleic acid is confined.


type Ib terminal bouton

Terminal inflated portion of the axon of a glutamatergic neuron, containing the specialized apparatus necessary for the tonic release neurotransmitters that will induce the contraction of muscle. Type Ib terminal boutons are larger than type Is terminal boutons.