Sandbox Reserved 1170: Difference between revisions
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=== Mechanisms of Insulin Secretion === | === Mechanisms of Insulin Secretion === | ||
One proposed pathway of insulin secretion by hGPR40 involves the activation of the [https://en.wikipedia.org/wiki/Gq_alpha_subunit G<sub>aq/11</sub>] protein complex. This complex then activates [[phospholipase C]] (PLC) which in turn | One proposed pathway of insulin secretion by hGPR40 involves the activation of the [https://en.wikipedia.org/wiki/Gq_alpha_subunit G<sub>aq/11</sub>] protein complex. This complex then activates [[phospholipase C]] (PLC) which in turn hydrolyses [https://en.wikipedia.org/wiki/Phosphatidylinositol_4,5-bisphosphate phosphatidylinositol 4,5-bisphosphate] to inositol 1,4,5-triphosphate (IP<sub>3</sub>) and diacylglycerol (DAG). IP<sub>3</sub> can then mediate the [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3560308/ influx of Ca<sup>2+</sup>] by moving into the cytoplasm, binding to the endoplasmic reticulum, and allowing for the release of Ca<sup>2+</sup> into the cytosol.<ref name="Burant"/> This increase in [Ca<sup>2+</sup>] amplifies the similar increase in [Ca<sup>2+</sup>] that results from high concentrations of glucose. In this way, hGPR40 mimics glucose dependent insulin secretion.<ref name="Itoh">PMID:12629551</ref> Overall, hGPR40 helps to amplify the Ca<sup>2+</sup> signal so that the cell secretes more insulin. | ||
Another pathway through which hGPR40 may induce insulin expression is through phospholipase D1 (PLD1). When free fatty acids bind to hGPR40, hGPR40 directly phosphorylates and activates PLD1. The PLD1 plays a role in controlling the organization of an actin network that plays in role in insulin secretion.<ref name="Burant"/> | Another pathway through which hGPR40 may induce insulin expression is through phospholipase D1 (PLD1). When free fatty acids bind to hGPR40, hGPR40 directly phosphorylates and activates PLD1. The PLD1 plays a role in controlling the organization of an actin network that plays in role in insulin secretion.<ref name="Burant"/> | ||
