Referenced in: none

Automatically associated channels: Kir1.1

Title: Inactivating properties of recombinant ROMK2 channels expressed in mammalian cells.

Authors: D F Riochet, R Mohammad-Panah, S C Hebert, G G MacGregor, I Baró, G Guihard, D Escande

Journal, date & volume: Biochem. Biophys. Res. Commun., 2001 Aug 17 , 286, 376-80

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11500048

Abstract
Biophysical properties of ROMK2 channel were investigated at physiological temperature, after reexpression of the recombinant ROMK2 protein in a mammalian cell expression system (COS-7). We observed that ROMK2 induced an inwardly rectifying K(+) current whether polyvalent cations were present or not. Above +10 mV, ROMK2-induced current exhibited a voltage- and time-dependent decay, consistent with an inactivation process. Inactivation of ROMK2-induced current was also seen in inside out patch from ROMK2-expressing Xenopus oocyte. In COS-7 cells, inactivation was found to account for most of the inward rectification. Mg(2+) and spermine modulated rectification by accelerating inactivation kinetics independently of membrane potential. These results establish for the first time ROMK2 properties in a mammalian cell expression system.