Integrin stimulation decreases tyrosine phosphorylation and activity of focal adhesion kinase in thymocytes.

Abstract FAK, focal adhesion kinase, is expressed in a variety of cell types and has been suggested to transduce signals brought about by integrin-extracellular matrix (ECM) interactions. Integrin stimulation increases tyrosine phosphorylation and activity of FAK in all the cells examined to date. In contrast, in thymocytes stimulation of VLA-4 (α 4 β 1 ) and LFA-1 (α L β 2 ) resulted in a marked decrease in tyrosine phosphorylation and activity of FAK.