Phosphatidylinositol kinase in rat pancreatic islets: subcellular distribution and sensitivity to calcium.
Plasma membrane of pancreatic islets contains a calcium sensitive phosphatidylinositol kinase. This enzyme catalyzes the first reaction in the pathway leading to the production of inositol trisphosphate, which is believed to cause a redistribution of intracellular calcium. Since the activity of this enzyme is inhibited by calcium (K0.5 = 10 microM), a loss of calcium from plasma membrane (the site of PI kinase) may be necessary for activation of the enzyme in vivo.
D019870:1-Phosphatidylinositol 4-Kinase; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000201:enzymology* / Q000648:ultrastructure; D010770:Phosphotransferases / Q000378:metabolism*; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism
D010770:Phosphotransferases; D019870:1-Phosphatidylinositol 4-Kinase; D002118:Calcium