Integrin crosstalk, in which ligation of one type of integrin changes the activity of another integrin on the same cell, has been observed in many cell types under a variety of conditions, but the molecular mechanism for this phenomenon has remained obscure. Now Blystone et al. (page ) have found that the ligation of the integrin αvβ3 inhibits the activity of calcium-calmodulin kinase II (CamKII), an enzyme essential for transducing signals from the α5β1 integrin on the same cell.
In cells that express only α5β1 and αvβ3 integrins, ligation of α5β1 induces cell migration and phagocytosis, and Blystone et al. show that the activity of CamKII is required for transduction of this signal. The signal can be blocked by CamKII inhibitors or by ligation of the αvβ3 receptor, and the cytoplasmic...
