Phosphatidylinositol 3,5-bisphosphate defines a novel PI 3-kinase pathway in resting mouse fibroblasts.
PtdIns(3,5)P2 is identified as the product of an agonist-independent, wortmannin-sensitive pathway in resting mouse cells. Results are presented here to indicate that PtdIns(3,5)P2 is formed by phosphorylation of PtdIns3P at the D-5 position, and they suggest that relatively constant cellular levels of PtdIns3P and PtdIns(3, 5)P2 are maintained by the concerted action of PtdIns3P 5-kinase and PtdIns(3,5)P2 5-phosphatase. These studies imply a novel mechanism for the action of PtdIns-specific phosphoinositide 3-hydroxykinases in mammalian cells.
Whiteford
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CC
Section of Virology and Oncology, Division of Biology, Kansas State University, Ackert Hall, Manhattan, KS 66506, USA.
Brearley
C A
CA
Ulug
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ET
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology*; D007399:Interphase; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000077191:Wortmannin
D000730:Androstadienes; D004791:Enzyme Inhibitors; D018129:Phosphatidylinositol Phosphates; C106336:phosphatidylinositol 3,5-diphosphate; C055525:phosphatidylinositol 3-phosphate; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D000077191:Wortmannin