Identification of a phosphatidylinositol 3-hydroxy kinase in plant cells: association with the cytoskeleton.
Radiolabelling experiments have revealed that plant cells contain the two 3-phosphorylated phosphoinositides: PtdIns3P and PtdIns(3,4)P2 [Brearley and Hanke (1992) Biochem. J. 283, 255-260]. However, nothing is known about the enzymes involved in the metabolism of these plant 3-phosphorylated phosphoinositides. In this study we demonstrate the presence of a PtdIns 3-hydroxy kinase(s) in plant cells. This activity was enriched in the cytoskeletal fraction whereas only low levels of phosphoinositide 3-hydroxy kinase could be detected in plasma membranes and microsomal preparations. This cytoskeletal phosphoinositide 3-hydroxy kinase was found to be wortmannin insensitive and thus resembles PtdIns-specific 3-hydroxy kinases of which vps34p is one example.
Department of Cell Biology, John Innes Centre for Plant Science Research, Norwich, U.K.
S K
SK
Dove
C W
CW
Lloyd
B K
BK
Drøbak
D000215:Acylation; D000730:Androstadienes / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003599:Cytoskeleton / Q000201:enzymology*; D018552:Daucus carota / Q000201:enzymology; D007553:Isotope Labeling; D008861:Microsomes / Q000201:enzymology; D009183:Mycotoxins / Q000494:pharmacology; D017830:Octoxynol / Q000494:pharmacology; D010715:Phosphatidylglycerols / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases; D010716:Phosphatidylinositols / Q000378:metabolism; D010739:Phospholipase D / Q000037:antagonists & inhibitors; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000077191:Wortmannin
D000730:Androstadienes; D009183:Mycotoxins; D010715:Phosphatidylglycerols; D010716:Phosphatidylinositols; D017830:Octoxynol; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D010739:Phospholipase D; D000077191:Wortmannin