ITGB7
Domain
The VWFA domain (or beta I domain) contains three cation-binding sites: the ligand-associated metal ion-binding site (LIMBS or SyMBS), the metal ion-dependent adhesion site (MIDAS), and the adjacent MIDAS site (ADMIDAS) (PubMed:14608374). This domain is also part of the ligand-binding site (PubMed:14608374). The MIDAS site is required for both rolling and adhesion (PubMed:14608374). The ADMIDAS site is required for rolling and mediates the negative regulatory effects of higher Ca(2+) concentration on ligand binding (PubMed:14608374). The LIMBS site is required for adhesion and mediates the positive regulatory effects of low Ca(2+) concentrations on ligand binding (PubMed:14608374).
Function
Integrin ITGA4/ITGB7 (alpha-4/beta-7) (Peyer patches-specific homing receptor LPAM-1) is an adhesion molecule that mediates lymphocyte migration and homing to gut-associated lymphoid tissue (GALT) (Probable). Integrin ITGA4/ITGB7 interacts with the cell surface adhesion molecules MADCAM1 which is normally expressed by the vascular endothelium of the gastrointestinal tract (PubMed:10837471, PubMed:14608374). Interacts also with VCAM1 and fibronectin, an extracellular matrix component (Probable). It recognizes one or more domains within the alternatively spliced CS-1 region of fibronectin (Probable). Interactions involve the tripeptide L-D-T in MADCAM1, and L-D-V in fibronectin (Probable). Integrin ITGAE/ITGB7 (alpha-E/beta-7, HML-1) is a receptor for E-cadherin (PubMed:10837471).
(Microbial infection) Binds to HIV-1 gp120, thereby allowing the virus to enter GALT, which is thought to be the major trigger of AIDS disease. Interaction would involve a tripeptide L-D-I in HIV-1 gp120.
Sequence Similarities
Belongs to the integrin beta chain family.
Tissue Specificity
Expressed in a variety of leukocyte lines.
Cellular localization
- Cell membrane
- Single-pass type I membrane protein
Alternative names
Integrin beta-7, Gut homing receptor beta subunit, ITGB7