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Coiled coil region of thrombospondin This domain family contains coiled coil region of subgroup B of thrombospondins, comprising TSP-3, TSP-4, and TSP-5, that assemble as pentamers. This region is located adjacent to the N-terminal domain (NTD) of thrombospondin (TSP), that mediates co-translational oligomerization via formation of a left-handed super-helix which binds hydrophilic signaling molecules such as vitamin D3 and vitamin A. Pentameric TSPs are stabilized by inter-subunit disulfide bonds formed between cysteine residues adjacent to the C-terminal end. TSP-5 is also known as cartilage oligomeric matrix protein (COMP). TSPs comprise a conserved family of extracellular, oligomeric, multidomain, calcium-binding glycoproteins. In mammals, they have several complex tissue-specific roles, including activities in wound healing and angiogenesis, connective tissue organization, vessel wall biology, and synaptogenesis, all mechanistically derived from interactions with cell surfaces, cytokines, growth factors, or components of the extracellular matrix (ECM) that together regulate many aspects of cell phenotype. In invertebrates, TSPs may have ancient functions such as bridging activities in cell-cell and cell-ECM interactions. Most protostomes and inferred basal metazoa encode a single TSP with the general domain organization of subgroup B TSPs and with a pentamerizing coiled coil. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",