Abstract
The β-cell is equipped with at least six voltage-gated Ca2+ (Cav) channel α1-subunits designated Ca v1.2, 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 β-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 β-cell displays some characteristic features to bring these mechanisms into play. In islet β-cells, Cav channels can be highly phosphorylated under basal conditions and thus marginally respond to further phosphorylation. In β-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 β-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 β-cells and also reviews our studies on newly identified mechanisms of β-cell Cav channel regulation.
Original language | English (US) |
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Pages (from-to) | E16-E28 |
Journal | American Journal of Physiology - Endocrinology and Metabolism |
Volume | 288 |
Issue number | 1 51-1 |
DOIs | |
State | Published - Jan 1 2005 |
Keywords
- Exocytotic proteins
- Inositol hexakisphosphate
- Pancreatic β-cell
- Type 1 diabetic serum
- Voltage-gated Ca channels
ASJC Scopus subject areas
- Physiology
- Endocrinology
- Biochemistry