Referenced in: none

Automatically associated channels: Kv1.4 , Kv1.5

Title: The sigma receptor as a ligand-regulated auxiliary potassium channel subunit.

Authors: Ebru Aydar, Christopher P Palmer, Vitaly A Klyachko, Meyer B Jackson

Journal, date & volume: Neuron, 2002 Apr 25 , 34, 399-410

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11988171

Abstract
The sigma receptor is a novel protein that mediates the modulation of ion channels by psychotropic drugs through a unique transduction mechanism depending neither on G proteins nor protein phosphorylation. The present study investigated sigma receptor signal transduction by reconstituting responses in Xenopus oocytes. Sigma receptors modulated voltage-gated K+ channels (Kv1.4 or Kv1.5) in different ways in the presence and absence of ligands. Association between Kv1.4 channels and sigma receptors was demonstrated by coimmunoprecipitation. These results indicate a novel mechanism of signal transduction dependent on protein-protein interactions. Domain accessibility experiments suggested a structure for the sigma receptor with two cytoplasmic termini and two membrane-spanning segments. The ligand-independent effects on channels suggest that sigma receptors serve as auxiliary subunits to voltage-gated K+ channels with distinct functional interactions, depending on the presence or absence of ligand.