Integrin alpha 9 beta 1

Integrin alpha 9 beta 1 is one of twelve integrin family adhesion receptors that share the beta 1 (CD29) subunit. It is the non-covalent heterodimer of 150 kDa alpha 9 and 130 kDa beta 1 type I transmembrane glycoprotein subunits. The  integrin alpha 9 beta 1 mediates cell adhesion to tenascin-C and VCAM-1 by binding to sequences distinct from the common integrin-recognition sequence, arginine-glycine-aspartic acid (RGD). A thrombin-cleaved NH(2)-terminal fragment of osteopontin containing the RGD sequence has recently been shown to also be a ligand for integrin alpha 9 beta 1.