Signal transduction proteins that associate with the platelet-derived growth factor (PDGF) receptor mediate the PDGF-induced release of glucose-6-phosphate dehydrogenase from permeabilized cells.
Permeabilized rat kidney cells rapidly released glucose 6-phosphate dehydrogenase (G6PD) following stimulation with peptide growth factors (Stanton, R.C., Seifter, J.L., Boxer, D.C., Zimmerman, E., and Cantley, L. C. (1991) J. Biol. Chem. 266, 12442-12448). To evaluate the signal transduction pathways mediating release of G6PD, two cell lines transfected with wild type or mutant platelet-derived growth factor (PDGF) receptors (PDGFR) were studied using two permeabilization protocols. G6PD release was evaluated by enzyme activity and Western blot analysis. PDGF caused a significant increase in G6PD release in 1 min in cells transfected with wild type PDGFR. PDGF did not stimulate G6PD release in cells transfected with tyrosine kinase-deficient PDGFR. PDGF did not stimulate G6PD release in cells transfected with partially autophosphorylation-deficient PDGFR in which four known signaling proteins do not associate with the PDGFR. The PDGF-stimulated release of G6PD was partially restored in PDGFR mutants in which either phosphatidylinositol-3-kinase or phospholipase C gamma 1 could associate with the PDGFR. Lastly, there was no basal or PDGF-stimulated phosphorylation of G6PD. We conclude that release of G6PD: 1) requires intrinsic PDGFR tyrosine kinase activity; 2) requires PDGFR autophosphorylation; 3) is mediated by signaling proteins that associate with the PDGFR; 4) is not mediated by direct phosphorylation of G6PD.
Tian
W N
WN
Renal Division, New England Deaconess Hospital, Boston, Massachusetts 02115.
Pignatare
J N
JN
Stanton
R C
RC
D000818:Animals; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D002463:Cell Membrane Permeability; D004285:Dogs; D004848:Epithelium / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D007668:Kidney; D008113:Liver Neoplasms; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000378:metabolism / Q000494:pharmacology*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor / Q000096:biosynthesis / Q000187:drug effects / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012503:Saponins / Q000494:pharmacology; D017384:Sequence Deletion; D015398:Signal Transduction; D014162:Transfection; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism
D007527:Isoenzymes; D010982:Platelet-Derived Growth Factor; D011994:Recombinant Proteins; D012503:Saponins; D005954:Glucosephosphate Dehydrogenase; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D020794:Receptor Protein-Tyrosine Kinases; D017479:Receptors, Platelet-Derived Growth Factor; D010738:Type C Phospholipases