Referenced in: none

Automatically associated channels: SK1

Title: Recombinant hTASK1 is an O(2)-sensitive K(+) channel.

Authors: A Lewis, M E Hartness, C G Chapman, I M Fearon, H J Meadows, C Peers, P J Kemp

Journal, date & volume: Biochem. Biophys. Res. Commun., 2001 Aug 3 , 285, 1290-4

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11478797

Abstract
Hypoxic inhibition of background K(+) channels is crucial to O(2) sensing by chemoreceptor tissues, but direct demonstration of O(2) sensitivity by any member of this K(+) channel family is lacking. HEK293 cells were transfected with a pcDNA3.1-hTASK1 construct; expression of hTASK1 was verified using RT-PCR and immunocytochemistry. Whole-cell K(+) currents of cells stably expressing hTASK-1 were, as anticipated, extremely sensitive to extracellular pH, within the physiological range (IC(50) approximately 7.0). All cells expressing this signature pH sensitivity were acutely modulated by pO(2); reduction of pO(2) from 150 to <40 mmHg (at pH 7.4) caused rapid and reversible suppression of pH-sensitive K(+) currents. Furthermore, these two regulatory signals clearly acted at the same channel, since the magnitude of the O(2)-sensitive current was dependent on the extracellular pH. These data represent the first direct verification that hTASK1 is O(2)-sensitive and reinforce the idea that this K(+) channel is key to O(2) sensing in chemoreceptors.