Referenced in: none

Automatically associated channels: Kir2.3

Title: Cloning and expression of a third calcium channel beta subunit.

Authors: A Castellano, X Wei, L Birnbaumer, E Perez-Reyes

Journal, date & volume: J. Biol. Chem., 1993 Feb 15 , 268, 3450-5

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/7679112

Abstract
The skeletal muscle dihydropyridine receptor/Ca2+ channel consists of five distinct subunits (alpha 1, alpha 2 delta, beta 1, and gamma). Homologous alpha 1, alpha 2 delta, and beta 2 subunits are expressed in heart and brain. The present study reports the cloning and expression of a third beta subunit, beta 3, which is expressed predominantly in brain. Its open reading frame encodes a protein with 484 amino acids with a predicted molecular mass of 54,571 Da. Coexpression of beta 3 with a cardiac alpha 1 in Xenopus oocytes induces similar changes in Ca2+ channel activity as beta 1 and beta 2, that is, it increases peak currents, modulates the voltage dependence of activation, and accelerates activation. In addition, beta 3 accelerates the rate of inactivation at positive test potentials.