Referenced in: none

Automatically associated channels: Kir3.1 , Kir3.2

Title: Dominant negative effects of a Gbeta mutant on G-protein coupled inward rectifier K+ channel.

Authors: Qi Zhao, Abla M Albsoul-Younes, Peng Zhao, Tohru Kozasa, Yasuko Nakajima, Shigehiro Nakajima

Journal, date & volume: FEBS Lett., 2006 Jul 10 , 580, 3879-82

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/16797547

Abstract
HEK293 cells were transfected with cDNAs for Gbeta1(W332A) [a mutant Gbeta1], Ggamma2, and inward rectifier K+ channels (Kir3.1/Kir3.2). Application of Gbeta1gamma2 protein to these cells activated the K+ channels only slightly. When mu-opioid receptors and Kir3.1/Kir3.2 were transfected, application of a mu-opioid agonist induced a Kir3 current. However, co-expression of Gbeta1(W332A) suppressed this current. Most likely, Gbeta1(W332A) inhibited the action of the endogenous Gbeta. Such a dominant negative effect of Gbeta1(W332A) was also observed in neuronal Kir3 channels in locus coeruleus. The mutant, Gbeta1(W332A) protein, although inactive, retains its ability to bind Kir3 and prevents the wild type Gbeta from activating the channel.