Translocation of pp60c-src from the plasma membrane to the cytosol after stimulation by platelet-derived growth factor.

Abstract

The src family of protein-tyrosine kinases has long been implicated in signal transduction by growth factor receptors. In particular, pp60c-src, the product of the protooncogene c-src, has been shown to associated with the activated platelet-derived growth factor (PDGF) receptor. We demonstrate that, following stimulation of quiescent cells with PDGF, pp60c-src is translocated from the plasma membrane to the cytosol. This phenomenon was better defined utilizing an isolated plasma membrane system. The release of pp60c-src from the membrane in response to PDGF is accompanied by a 4-fold activation of its kinase activity and by phosphorylation at the amino terminus on serine/threonine residues ..