Referenced in: none

Automatically associated channels: Cav1.2 , Cav1.3 , Cav2.1 , Cav2.2 , Cav2.3 , Cav3.1

Title: Beta-cell CaV channel regulation in physiology and pathophysiology.

Authors: Shao-Nian Yang, Per-Olof Berggren

Journal, date & volume: Am. J. Physiol. Endocrinol. Metab., 2005 Jan , 288, E16-28

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15585596

Abstract
The beta-cell is equipped with at least six voltage-gated Ca2+ (CaV) channel alpha1-subunits designated CaV1.2, CaV1.3, CaV2.1, CaV2.2, CaV2.3, and CaV3.1. These principal subunits, together with certain auxiliary subunits, assemble into different types of CaV channels conducting L-, P/Q-, N-, R-, and T-type Ca2+ currents, respectively. The beta-cell shares customary mechanisms of CaV channel regulation with other excitable cells, such as protein phosphorylation, Ca2+-dependent inactivation, and G protein modulation. However, the beta-cell displays some characteristic features to bring these mechanisms into play. In islet beta-cells, CaV channels can be highly phosphorylated under basal conditions and thus marginally respond to further phosphorylation. In beta-cell lines, CaV channels can be surrounded by tonically activated protein phosphatases dominating over protein kinases; thus their activity is dramatically enhanced by inhibition of protein phosphatases. During the last 10 years, we have revealed some novel mechanisms of beta-cell CaV channel regulation under physiological and pathophysiological conditions, including the involvement of exocytotic proteins, inositol hexakisphosphate, and type 1 diabetic serum. This minireview highlights characteristic features of customary mechanisms of CaV channel regulation in beta-cells and also reviews our studies on newly identified mechanisms of beta-cell CaV channel regulation.