Referenced in: none

Automatically associated channels: Kir2.1 , Kir2.2 , Kir3.2

Title: Yeast screen for constitutively active mutant G protein-activated potassium channels.

Authors: B A Yi, Y F Lin, Y N Jan, L Y Jan

Journal, date & volume: Neuron, 2001 Mar , 29, 657-67

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11301025

Abstract
GIRK2 is a major contributor to G protein-activated inward rectifier potassium channels in the mammalian brain. How GIRK channels open upon contact with Gbetagamma remains unknown. Using a yeast genetic screen to select constitutively active mutants from a randomly mutagenized GIRK2 library, we identified five gating mutations at four residues in the transmembrane domain. Further mutagenesis indicates that GIRK channel opening involves a rotation of the transmembrane segments, bringing one of these residues (V188) to a pore-lining position in the open conformation. Combined with double-mutant studies, these findings suggest that GIRK channels gate by moving from the open conformation inferred from our yeast study of Kir2.1 to a closed conformation perhaps resembling the known KcsA structure.