Relationship between phosphoinositide kinase activities and protein tyrosine phosphorylation in plasma membranes from A431 cells.
Production of PtdIns(4)P and PtdIns(4,5)P2 by plasma-membrane preparations from A431 cells was selectively stimulated in a dose-dependent manner by epidermal growth factor (EGF) in the presence of Na3VO4. Na3VO4 itself mimicked this effect, which was overcome after treatment by a specific phosphotyrosyl phosphatase isolated from A431 cells. PtdIns and PtdIns(4)P kinase activities were present in phosphotyrosyl-proteins isolated from EGF- and/or Na3VO4-stimulated A431 cells by immunoaffinity using an anti-phosphotyrosine antibody. These data suggest for the first time an EGF-dependent regulation of PtdIns 4-kinase and PtdIns(4)P 5-kinase activities by a mechanism involving a tyrosine-phosphorylation process.
Payrastre
B
B
INSERM U326, Hôpital Purpan, Toulouse, France.
Plantavid
M
M
Breton
M
M
Chambaz
E
E
Chap
H
H
D019870:1-Phosphatidylinositol 4-Kinase; D000255:Adenosine Triphosphate / Q000378:metabolism; D002294:Carcinoma, Squamous Cell; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007700:Kinetics; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000378:metabolism; D010716:Phosphatidylinositols / Q000302:isolation & purification / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010750:Phosphoproteins / Q000302:isolation & purification; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*
D008565:Membrane Proteins; D009363:Neoplasm Proteins; D010716:Phosphatidylinositols; D010750:Phosphoproteins; D010761:Phosphorus Radioisotopes; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D019870:1-Phosphatidylinositol 4-Kinase; D011505:Protein-Tyrosine Kinases; D010749:Phosphoprotein Phosphatases; D017027:Protein Tyrosine Phosphatases