Referenced in: none

Automatically associated channels: BKβ1 , Slo1

Title: Cloning, expression, and distribution of a Ca(2+)-activated K+ channel beta-subunit from human brain.

Authors: J Tseng-Crank, N Godinot, T E Johansen, P K Ahring, D Strøbaek, R Mertz, C D Foster, S P Olesen, P H Reinhart

Journal, date & volume: Proc. Natl. Acad. Sci. U.S.A., 1996 Aug 20 , 93, 9200-5

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/8799178

Abstract
We have cloned and expressed a Ca(2+)-activated K+ channel beta-subunit from human brain. The open reading frame encodes a 191-amino acid protein possessing significant homology to a previously described subunit cloned from bovine muscle. The gene for this subunit is located on chromosome 5 at band q34 (hslo-beta). There is no evidence for alternative RNA splicing of this gene product. hslo-beta mRNA is abundantly expressed in smooth muscle, but expression levels are low in most other tissues, including brain. Brain subregions in which beta-subunit mRNA expression is relatively high are the hippocampus and corpus callosum. The coexpression of hslo-beta mRNA together with hslo-alpha subunits in either Xenopus oocytes or stably transfected HEK 293 cells give rise to Ca(2+)-activated potassium currents with a much increased calcium and/or voltage sensitivity. These data indicate that the beta-subunit shows a tissue distribution different to that of the alpha-subunit, and in many tissues there may be no association of alpha-subunits with beta-subunits. These beta-subunits can play a functional role in the regulation of neuronal excitability by tuning the Ca2+ and/or the voltage dependence of alpha-subunits.