Regulators of G protein signaling (RGS) proteins constitutively activate Gβγ-gated potassium channels

被引:60
作者
Bünemann, M [1 ]
Hosey, MM [1 ]
机构
[1] Northwestern Univ, Sch Med, Dept Biol Chem & Mol Pharmacol, Chicago, IL 60611 USA
关键词
D O I
10.1074/jbc.273.47.31186
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Here we report novel effects of regulators of G protein signaling (RGS) on G protein-regulated ion channels. RGS3 and RGS4 induced a substantial increase in currents through the G beta gamma-regulated inwardly rectifying K+ channels, I-K(ACh), in the absence of receptor activation. Concomitantly, the amount of current that could be activated by agonist was reduced. Pretreatment with pertussis toxin or a muscarinic receptor antagonist abolished agonist-induced currents but did not modify RGS effects. Cotransfection of cells with a G beta gamma-binding protein significantly reduced the RGS4-induced basal I-K(ACh) currents. The RGS proteins also modified the properties of another G beta gamma effector, the N-type Ca2+ channels. These observations strongly suggest that RGS proteins increase the availability of G beta gamma in addition to their previously described GTPase-activating function.
引用
收藏
页码:31186 / 31190
页数:5
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