Effect of H-ras proteins on the activity of polyphosphoinositide phospholipase C in HL60 membranes.
The present study was undertaken to investigate whether purified ras proteins can affect the activity of polyphosphoinositide specific phospholipase C in a cell-free membrane system. For this purpose we used homogenous preparations of the proto-oncogenic (H-ras(gly 12)) and the oncogenic (H-ras(val 12)) forms of the human H-ras proteins and membranes prepared from the human leukemic HL60 cells. We demonstrate that both the proto-oncogenic and the oncogenic form of H-ras proteins stimulate phospholipase C activity only when coupled to non-hydrolysable analogues of GTP.
Cockcroft
S
S
Department of Physiology, University College London, U.K.
Bar-Sagi
D
D
D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology*; D002474:Cell-Free System; D019204:GTP-Binding Proteins / Q000378:metabolism; D011905:Genes, ras; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism* / Q000494:pharmacology; D016283:Proto-Oncogene Proteins p21(ras); D013873:Thionucleotides / Q000378:metabolism
D011518:Proto-Oncogene Proteins; D013873:Thionucleotides; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D019204:GTP-Binding Proteins; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)