Regulation of phospholipase C by G proteins.
Specific phospholipase C enzymes can hydrolyse phosphatidylinositol 4,5-bisphosphate into two products: inositol 1,4,5-trisphosphate, which regulates the release of intracellular calcium stores, and diacylglycerol, which can stimulate protein kinase C. A new group of G proteins, the Gq subfamily, have recently been shown to mediate the regulation of this activity by a variety of hormones. How do different members of this family modulate unique phospholipase C isozymes? What is the mechanism of this regulation? How might the Gq subfamily act to modulate other important second messenger pathways? The tools to answer these questions are being rapidly developed.
Sternweis
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Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235.
Smrcka
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D000818:Animals; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D006868:Hydrolysis; D019269:Phosphatidylinositol 4,5-Diphosphate; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D010716:Phosphatidylinositols / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism*
D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D010727:Phosphoric Diester Hydrolases; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D043265:Phosphatidylinositol Diacylglycerol-Lyase