Integrin beta-3 subunit (IPR027068)
Short name: Integrin_beta-3
- Integrin beta subunit (IPR015812)
- Integrin beta-3 subunit (IPR027068)
Integrins are the major metazoan receptors for cell adhesion to extracellular matrix proteins and, in vertebrates, also play important roles in certain cell-cell adhesions, make transmembrane connections to the cytoskeleton and activate many intracellular signalling pathways [PMID: 12297042, PMID: 12361595]. The integrin receptors are composed of alpha and beta subunit heterodimers. Each subunit crosses the membrane once, with most of the polypeptide residing in the extracellular space, and has two short cytoplasmic domains. Some members of this family have EGF repeats at the C terminus and also have a vWA domain inserted within the integrin domain at the N terminus.
Most integrins recognise relatively short peptide motifs, and in general require an acidic amino acid to be present. Ligand specificity depends upon both the alpha and beta subunits [PMID: 12234368]. There are at least 18 types of alpha and 8 types of beta subunits recognised in humans [PMID: 14689578]. Each alpha subunit tends to associate only with one type of beta subunit, but there are exceptions to this rule [PMID: 2467745]. Each association of alpha and beta subunits has its own binding specificity and signalling properties. Many integrins require activation on the cell surface before they can bind ligands. Integrins frequently intercommunicate, and binding at one integrin receptor activate or inhibit another.
Integrin alpha-V/beta-3 is a receptor for cytotactin, fibronectin, laminin, matrix metalloproteinase-2, osteopontin, osteomodulin, prothrombin, thrombospondin, vitronectin and von Willebrand factor. Integrin alpha-IIB/beta-3 is a receptor for fibronectin, fibrinogen, plasminogen, prothrombin, thrombospondin and vitronectin. Integrins alpha-IIB/beta-3 and alpha-V/beta-3 recognise the sequence R-G-D in a wide array of ligands. Integrin alpha-IIB/beta-3 recognises the sequence H-H-L-G-G-G-A-K-Q-A-G-D-V in fibrinogen gamma chain. Following activation integrin alpha-IIB/beta-3 brings about platelet/platelet interaction through binding of soluble fibrinogen. This step leads to rapid platelet aggregation which physically plugs ruptured endothelial surface.
GO:0060055 angiogenesis involved in wound healing
GO:0007155 cell adhesion
GO:0007160 cell-matrix adhesion
GO:0007044 cell-substrate junction assembly
GO:0007229 integrin-mediated signaling pathway
GO:0070527 platelet aggregation
GO:0030334 regulation of cell migration
GO:0004872 receptor activity
GO:0008305 integrin complex
- PTHR10082:SF25 (PTHR10082:SF25)