Inhibition of Phosphatases and Increased Ca 2+ Channel Activity by Inositol Hexakisphosphate
- 17 October 1997
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 278 (5337), 471-474
- https://doi.org/10.1126/science.278.5337.471
Abstract
Inositol hexakisphosphate (InsP6), the dominant inositol phosphate in insulin-secreting pancreatic β cells, inhibited the serine-threonine protein phosphatases type 1, type 2A, and type 3 in a concentration-dependent manner. The activity of voltage-gated L-type calcium channels is increased in cells treated with inhibitors of serine-threonine protein phosphatases. Thus, the increased calcium channel activity obtained in the presence of InsP6 might result from the inhibition of phosphatase activity. Glucose elicited a transient increase in InsP6 concentration, which indicates that this inositol polyphosphate may modulate calcium influx over the plasma membrane and serve as a signal in the pancreatic β cell stimulus-secretion coupling.Keywords
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