Guanine nucleotide–binding proteins (G proteins) are critically important mediators of many signal-transduction systems. Several important sites regulating stimulus-secretion coupling and release of insulin from pancreatic β-cells are modulated by G proteins. Gs mediates increases in intracellular cAMP associated with hormone-induced stimulation of insulin secretion. GI, mediates decreases in intracellular cAMP caused by inhibitors of insulin secretion, e.g., epinephrine, somatostatin, prostaglandin E2, and galanin. G proteins also regulate ion channels, phospholipases, and distal sites in exocytosis. Cholera and pertussis toxins irreversibly ADP ribosylate G proteins and are important tools that can be used both to manipulate G-protein–dependent modulators of insulin secretion and detect and quantify G proteins by electrophoretic techniques. The stage is set to pursue these initial observations in greater depth and ascertain whether G-protein research will provide important new insights into normal and abnormal regulation of insulin secretion.
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Perspectives in Diabetes| January 01 1991
G Proteins and Modulation of Insulin Secretion
R Paul Robertson;
Elizabeth R Seaquist;
Address correspondence and reprint requests to R. Paul Robertson, MD University of Minnesota, Department of Medicine, Diabetes Center, Box 101 UMHC, Minneapolis, MN 55455.
R Paul Robertson, Elizabeth R Seaquist, Timothy F Walseth; G Proteins and Modulation of Insulin Secretion. Diabetes 1 January 1991; 40 (1): 1–6. https://doi.org/10.2337/diab.40.1.1
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