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


Journal Article

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.

Full Text

Cited Authors

  • Tseng-Crank, J; Godinot, N; Johansen, TE; Ahring, PK; Strøbaek, D; Mertz, R; Foster, CD; Olesen, SP; Reinhart, PH

Published Date

  • August 1996

Published In

Volume / Issue

  • 93 / 17

Start / End Page

  • 9200 - 9205

PubMed ID

  • 8799178

Pubmed Central ID

  • 8799178

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.93.17.9200


  • eng