Tyrosine phosphorylation of G protein alpha subunits by pp60c-src.

Journal Article (Journal Article)

A number of lines of evidence suggest that cross-talk exists between the cellular signal transduction pathways involving tyrosine phosphorylation catalyzed by members of the pp60c-src kinase family and those mediated by guanine nucleotide regulatory proteins (G proteins). In this study, we explore the possibility that direct interactions between pp60c-src and G proteins may occur with functional consequences. Preparations of pp60c-src isolated by immunoprecipitation phosphorylate on tyrosine residues the purified G-protein alpha subunits (G alpha) of several heterotrimeric G proteins. Phosphorylation is highly dependent on G-protein conformation, and G alpha(GDP) uncomplexed by beta gamma subunits appears to be the preferred substrate. In functional studies, phosphorylation of stimulatory G alpha (G alpha s) modestly increases the rate of binding of guanosine 5'-[gamma-[35S]thio]triphosphate to Gs as well as the receptor-stimulated steady-state rate of GTP hydrolysis by Gs. Heterotrimeric G proteins may represent a previously unappreciated class of potential substrates for pp60c-src.

Full Text

Duke Authors

Cited Authors

  • Hausdorff, WP; Pitcher, JA; Luttrell, DK; Linder, ME; Kurose, H; Parsons, SJ; Caron, MG; Lefkowitz, RJ

Published Date

  • July 1, 1992

Published In

Volume / Issue

  • 89 / 13

Start / End Page

  • 5720 - 5724

PubMed ID

  • 1378615

Pubmed Central ID

  • PMC49368

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.89.13.5720


  • eng

Conference Location

  • United States