Ichiro Niki
Department of Pharmacology, Nagoya Univesity School of Medicine, Nagoya
466-8550, Japan
Abstract: Recent progress in electrophysiological and microscopic
techniques have enabled us to estimate exocytotic and pre-exocytotic events
in the secretory machinery in single pancreatic beta-cells. We have been
studying mechanisms involved in the regulation of insulin granule movement,
which supplies release-ready granules, by direct visualization of granule
traffic in living beta-cells and found the movement to be regulated by a
mechanism different from that controlling exocytosis. From the obtained
findings together with those from electrophysiological approaches, a new
understanding of the role of the crucial second
messenger Ca2+, and other second messengers, as well as resultant
protein phosphorylation has been generated. The aim of this review is to
describe a synergistic network for the control of insulin release by second
messengers and protein kinases.
Keywords: Pancreatic beta-cell, Granule traffic, Myosin, Protein phosphorylation,
Ca2+