Inositol hexakisphosphate stimulates non-Ca 2+ -mediated and primes Ca 2+ -mediated exocytosis of insulin by activation of protein kinase C
- 29 April 1997
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 94 (9) , 4435-4439
- https://doi.org/10.1073/pnas.94.9.4435
Abstract
D-myo-inositol 1,2,3,4,5,6-hexakisphosphate (InsP6), formed via complex pathways of inositol phosphate metabolism, composes the main bulk of inositol polyphosphates in the cell. Relatively little is known regarding possible biological functions for InsP6. We now show that InsP6 can modulate insulin exocytosis in permeabilized insulin-secreting cells. Concentrations of InsP6 above 20 microM stimulated insulin secretion at basal Ca2+-concentration (30 nM) and primed Ca2+-induced exocytosis (10 microM), both effects being due to activation of protein kinase C. Our results suggest that InsP6 can play an important modulatory role in the regulation of processes such as exocytosis in insulin-secreting cells. The specific role for InsP6 can then be to recruit secretory granules to the site of exocytosis.Keywords
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