Activation of c-Src and Fyn kinases by protein-tyrosine phosphatase RPTPalpha is substrate-specific and compatible with lipid raft localization.

ABSTRACT: Src family tyrosine kinases (SFKs) function in multiple signaling pathways, raising the question of how appropriate regulation and substrate choice are achieved. SFK activity is modulated by several protein-tyrosine phosphatases, among which RPTPalpha and SHP2 are the best established. We studied how RPTPalpha affects substrate specificity and regulation of c-Src and Fyn in response to epidermal growth factor and platelet-derived growth factor. We find that RPTPalpha, in a growth factor-specific manner, directs the specificity of these kinases toward a specific subset of SFK substrates, particularly the focal adhesion protein Paxillin and the lipid raft scaffolding protein Cbp/PAG. A significant fraction of RPTPalpha is present in lipid rafts, where its targets Fyn and Cbp/PAG reside, and

SUBMITTER: Vacaresse N 

PROVIDER: S-EPMC2602903 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature