Format

Send to

Choose Destination
Biochem Biophys Res Commun. 1995 Jul 26;212(3):1022-8.

G beta gamma directly binds to the carboxyl terminus of the G protein-gated muscarinic K+ channel, GIRK1.

Author information

1
Department of Cell Biology and Signaling, Yamagata University School of Medicine, Japan.

Abstract

beta gamma Subunits of heterotrimeric GTP-binding proteins (G beta gamma) activate the inwardly rectifying muscarinic K+ channel, GIRK1. The significant role for the carboxyl (C) terminus of GIRK1 in this interaction has been suggested. However, it is still unknown whether G beta gamma directly interacts with GIRK1. To elucidate the molecular basis of G beta gamma-activation of GIRK1, we examined the binding properties of G beta gamma to the C terminus of GIRK1 cloned from mouse brain cDNA library (MB-GIRK1). The C terminus of MB-GIRK1 fused with glutathione S-transferase directly bound to purified G beta gamma. Incubation of the C terminus with Gi pretreated with GTP gamma S, but not with GDP, resulted in the binding of Gi beta gamma to the protein. Purified G alpha-GDP, but not G alpha-GTP gamma S, inhibited the binding of G beta gamma to the fusion protein. These results indicate that G beta gamma dissociated from G alpha may directly bind to the C terminus of GIRK1.

PMID:
7626088
DOI:
10.1006/bbrc.1995.2072
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center