Niki I, Hidaka H. Roles of intracellular Ca2+ receptors in the pancreatic beta-cell in insulin secretion.
Mol Cell Biochem 1999;
190:119-24. [PMID:
10098978 DOI:
10.1023/a:1006997822987]
[Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ca2+ is the central second messenger in the regulation of insulin release from the pancreatic beta-cell; and intracellular Ca2+ -binding proteins, classified into two groups, the EF hand proteins and the Ca2+/phospholipid binding proteins, are considered to mediate Ca2+ signaling. A number of Ca binding proteins have been suggested to participate in the secretory machinery in the beta-cell. Calmodulin, the ubiquitous EF hand protein, is the predominant intracellular Ca2+ receptor that modulates insulin release via the multiplicity of its binding to target proteins including protein kinases. Other Ca binding proteins such as calcyclin and the Ca2+/phospholipid binding proteins may also be suggested to be involved. Ca2+ influx from the extracellular space appears to be responsible for exocytosis of insulin via Ca2+ -dependent protein/protein interactions. On the other hand, intracellular Ca2+ mobilization resulting in secretory granule movement may be controlled by Ca2+/calmodulin-dependent protein phosphorylation. Thus, Ca2+ exerts versatile effects on the secretory cascade via binding to specific binding proteins in the pancreactic beta-cells.
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