Neuron
Volume 38, Issue 2, 24 April 2003, Pages 225-235
Journal home page for Neuron

Article
Conformational Rearrangements Associated with the Gating of the G Protein-Coupled Potassium Channel Revealed by FRET Microscopy

https://doi.org/10.1016/S0896-6273(03)00193-4Get rights and content
Under an Elsevier user license
open archive

Abstract

G protein-coupled potassium channels (GIRK/Kir3.x) are key determinants that translate inhibitory chemical neurotransmission into changes in cellular excitability. To understand the mechanism of channel activation by G proteins, it is necessary to define the structural rearrangements in the channel that result from interaction with Gβγ subunits. In this study we used a combination of fluorescence spectroscopy and through-the-objective total internal reflection microscopy to monitor the conformational rearrangements associated with the activation of GIRK channels in single intact cells. We detect activation-induced changes in FRET consistent with a rotation and expansion of the termini along the central axis of the channel. We propose that this rotation and expansion of the termini drives the channel to open by bending and possibly rotating the second transmembrane segment.

Cited by (0)