Structural basis for modulation of gating property of G protein-gated inwardly rectifying potassium ion channel (GIRK) by i/o-family G protein α subunit (Gαi/o).

ABSTRACT: G protein-gated inwardly rectifying potassium channel (GIRK) plays a crucial role in regulating heart rate and neuronal excitability. The gating of GIRK is regulated by the association and dissociation of G protein βγ subunits (Gβγ), which are released from pertussis toxin-sensitive G protein α subunit (Gα(i/o)) upon GPCR activation in vivo. Several lines of evidence indicate that Gα(i/o) also interacts directly with GIRK, playing functional roles in the signaling efficiency and the modulation of the channel activity. However, the underlying mechanism for GIRK regulation by Gα(i/o) remains to be elucidated. Here, we performed NMR analyses of the interaction between the cytoplasmic region of GIRK1 and Gα(i3) in the GTP-bound state. The NMR spectral changes of Gα upon the addition of GIRK as

SUBMITTER: Mase Y 

PROVIDER: S-EPMC3365990 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature