CD49e, the alpha 5 integrin, noncovalently associates with the beta 1integrin (CD29) to form VLA-5 integrin complex. CD49e itself is composed of two disulfide-linked chains of 135 kDa and 25 kDa. VLA-5 binds to RGD sequence of fibronectin, and to neural adhesion molecule L1. It is important in maintaining the integrity of endothelial monolayers, in monocyte migration into the extracellular tissues, and it also provides a co-stimulatory signal to T cells and enhances receptor and complement receptor-mediated phagocytosis.
