XB-ART-19102Neuron November 1, 1995; 15 (5): 1133-43.
Evidence that direct binding of G beta gamma to the GIRK1 G protein-gated inwardly rectifying K+ channel is important for channel activation.
Activation of G protein-gated K+ channels by G protein-coupled receptors contributes to parasympathetic regulation of heart rate in the atrium and inhibitory postsynaptic potentials in the peripheral and central nervous system. Having found that G beta gamma activates the cloned GIRK1 channel, we now report evidence for direct binding of G beta gamma to both the N-terminal hydrophilic domain and amino acids 273-462 of the C-terminal domain of GIRK1. These direct interactions are physiologically important because synthetic peptides derived from either domain reduce the G beta gamma binding as well as the G beta gamma activation of the channel. Moreover, the N-terminal domain may also bind trimeric G alpha beta gamma, raising the possibility that physical association of G protein-coupled receptors, G proteins, and K+ channels partially accounts for their compartmentalization and hence rapid and specific channel activation by receptors.
PubMed ID: 7576656
Article link: Neuron
Species referenced: Xenopus
Genes referenced: kcnj3