Expression levels of RGS7 and RGS4 proteins determine the mode of regulation of the G protein-activated K+ channel and control regulation of RGS7 by Gβ5

Tal Keren-Raifman, Amal K. Bera, Dror Zveig, Sagit Peleg, D. Scott Witherow, Vladlen Z. Slepak, Nathan Dascal

Research output: Contribution to journalArticle

21 Scopus citations

Abstract

Regulators of G protein signaling RGS4 and RGS7 accelerate the kinetics of K+ channels (GIRKs) in the Xenopus oocyte system. Here, via quantitative analysis of RGS expression, we reveal biphasic effects of RGSs on GIRK regulation. At low concentrations, RGS4 inhibited basal GIRK activity, but stimulated it at high concentrations. RGS7, which is associated with the G protein subunit Gβ5, is regulated by Gβ5 by two distinct mechanisms. First, Gβ5 augments RGS7 activity, and second, it increases its expression. These dual effects resolve previous controversies regarding RGS4 and RGS7 function and indicate that they modulate signaling by mechanisms supplementary to their GTPase-activating protein activity.

Original languageEnglish (US)
Pages (from-to)20-28
Number of pages9
JournalFEBS letters
Volume492
Issue number1-2
DOIs
StatePublished - Mar 9 2001

Keywords

  • G protein
  • G protein-activated K channel
  • Gβ5
  • Potassium channel
  • Regulator of G protein signaling
  • Xenopus oocyte

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

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