Kindlin-2 (Mig-2): a co-activator of beta(3) integrins

作者：Ma Yan Qing; Qin Jun; Wu Chuanyue; Plow Edward F^*

来源：The Journal of Cell Biology, 2008, 181(3): 439-446.

DOI：10.1083/jcb.200710196

Integrin activation is essential for dynamically linking the extracellular environment and cytoskeletal/signaling networks. Activation is controlled by integrins' short cytoplasmic tails (CTs). It is widely accepted that the head domain of talin (talin-H) can mediate integrin activation by binding to two sites in integrin beta's CT; in integrin beta(3) this is an NPLY747 motif and the membrane-proximal region. Here, we show that the C-terminal region of integrin beta(3) CT, composed of a conserved (TST)-T-752 region and NITY759 motif, supports integrin activation by binding to a cytosolic binding partner, kindlin-2, a widely distributed PTB domain protein. Co-transfection of kindlin-2 with talin-H results in a synergistic enhancement of integrin alpha(IIb)beta(3) activation. Furthermore, siRNA knockdown of endogenous kindlin-2 impairs talin-induced alpha(IIb)beta(3) activation in transfected CHO cells and blunts alpha(v)beta(3)-mediated adhesion and migration of endothelial cells. Our results thus identify kindlin-2 as a novel regulator of integrin activation; it functions as a coactivator.

• 出版日期2008-5-5