PH sensing in the two-pore domain K+ channel, TASK2.

ABSTRACT: TASK2 is a member of the two-pore domain K(+) channel family that plays a role in acid-base homeostasis; TASK2 knockout animals have plasma electrolyte patterns typical of the human clinical condition of renal tubular acidosis. It is expressed preferentially in epithelia, including the proximal tubules of the kidney. In common with the other TASK channels, TASK2 is sensitive to changes in extracellular pH, although the molecular mechanism of such pH sensing is not understood. We have examined the role of charged residues in the extracellular domains in pH sensing using a mutational approach. Mutant channels were expressed in CHO cells and studied by whole-cell and single-channel patch clamp. Neutralization of no single amino acid in isolation gave complete loss of pH sensitivity. However,

SUBMITTER: Morton MJ 

PROVIDER: S-EPMC1276079 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature