ID:COMP_HUMAN DESCRIPTION: RecName: Full=Cartilage oligomeric matrix protein; Short=COMP; AltName: Full=Thrombospondin-5; Short=TSP5; Flags: Precursor; FUNCTION: May play a role in the structural integrity of cartilage via its interaction with other extracellular matrix proteins such as the collagens and fibronectin. Can mediate the interaction of chondrocytes with the cartilage extracellular matrix through interaction with cell surface integrin receptors. Could play a role in the pathogenesis of osteoarthritis. Potent suppressor of apoptosis in both primary chondrocytes and transformed cells. Suppresses apoptosis by blocking the activation of caspase-3 and by inducing the IAP family of survival proteins (BIRC3, BIRC2, BIRC5 and XIAP). Essential for maintaining a vascular smooth muscle cells (VSMCs) contractile/differentiated phenotype under physiological and pathological stimuli. Maintains this phenotype of VSMCs by interacting with ITGA7 (By similarity). COFACTOR: Binds 11-14 calcium ions per subunit. SUBUNIT: Pentamer; disulfide-linked. Exists in a more compact conformation in the presence of calcium and shows a more extended conformation in the absence of calcium. Interacts with ITGB3, ITGA5 and FN1. Binding to FN1 requires the presence of divalent cations (Ca(2+), Mg(2+) or Mn(2+)). The greatest amount of binding is seen in the presence of Mn(2+). Interacts with MATN1, MATN3, MATN4 and ACAN. Binds heparin, heparan sulfate and chondroitin sulfate. EDTA dimishes significantly its binding to ACAN and abolishes its binding to MATN3, MATN4 and chondroitin sulfate. Interacts with collagen I, II and IX, and interaction with these collagens is dependent on the presence of zinc ions. Interacts with ADAMTS12. Interacts with ITGA7 (By similarity). SUBCELLULAR LOCATION: Secreted, extracellular space, extracellular matrix. TISSUE SPECIFICITY: Abundantly expressed in the chondrocyte extracellular matrix, and is also found in bone, tendon, ligament and synovium and blood vessels. Increased amounts are produced during late stages of osteoarthritis in the area adjacent to the main defect. DEVELOPMENTAL STAGE: Present during the earliest stages of limb maturation and is later found in regions where the joints develop. DOMAIN: The cell attachment motif mediates the attachment to chondrocytes. It mediates the induction of both the IAP family of survival proteins and the antiapoptotic response. DOMAIN: The TSP C-terminal domain mediates interaction with FN1 and ACAN. DOMAIN: Each of the eight TSP type-3 repeats binds two calcium ions. The TSP C-terminal domain binds three calcium ions. DISEASE: Defects in COMP are the cause of multiple epiphyseal dysplasia type 1 (EDM1) [MIM:132400]. EDM is a generalized skeletal dysplasia associated with significant morbidity. Joint pain, joint deformity, waddling gait, and short stature are the main clinical signs and symptoms. EDM is broadly categorized into the more severe Fairbank and the milder Ribbing types. DISEASE: Defects in COMP are the cause of pseudoachondroplasia (PSACH) [MIM:177170]. PSAC is a dominantly inherited chondrodysplasia characterized by short stature and early-onset osteoarthrosis. PSACH is more severe than EDM1 and is recognized in early childhood. SIMILARITY: Belongs to the thrombospondin family. SIMILARITY: Contains 4 EGF-like domains. SIMILARITY: Contains 1 TSP C-terminal (TSPC) domain. SIMILARITY: Contains 8 TSP type-3 repeats. SEQUENCE CAUTION: Sequence=AAB86501.1; Type=Erroneous gene model prediction; WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/COMP";
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on P49747
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
Biological Process: GO:0001501 skeletal system development GO:0003417 growth plate cartilage development GO:0006915 apoptotic process GO:0007155 cell adhesion GO:0009887 animal organ morphogenesis GO:0030198 extracellular matrix organization GO:0043066 negative regulation of apoptotic process GO:0060173 limb development
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Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
