GAIP and RGS4 are GTPase-activating proteins for the G(i) subfamily of G protein α subunits

David M. Berman, Thomas M. Wilkie, Alfred G. Gilman

Research output: Contribution to journalArticle

623 Scopus citations

Abstract

A novel class of regulators of G protein signaling (RGS) proteins has been identified recently. Genetic evidence suggests that RGS proteins inhibit G protein-mediated signaling at the level of the receptor-G protein interaction or the G protein α subunit itself. We have found that two RGS family members, GAIP and RGS4, are GTPase-activating proteins (GAPs), accelerating the rate of GTP hydrolysis by G(iα1) at least 40-fold. All G(i) subfamily members assayed were substrates for these GAPs; G(sα) was not. RGS4 activates the GTPase activity of certain G(iα1) mutants (e.g., R178C), but not others (e.g., Q204L). The GAP activity of RGS proteins is consistent with their proposed role as negative regulators of G protein-mediated signaling.

Original languageEnglish (US)
Pages (from-to)445-452
Number of pages8
JournalCell
Volume86
Issue number3
DOIs
StatePublished - Aug 9 1996

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Fingerprint Dive into the research topics of 'GAIP and RGS4 are GTPase-activating proteins for the G(i) subfamily of G protein α subunits'. Together they form a unique fingerprint.

  • Cite this