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.

W.N Tian,J.N Pignatare,R.C Stanton

doi:10.1016/s0021-9258(17)36695-4

W.N Tian, J.N Pignatare + Show 1 more

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https://doi.org/10.1016/s0021-9258(17)36695-4

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Journal: The Journal of biological chemistry	Publication Date: May 1, 1994
Citations: 91	License type: cc-by

Affiliation: Deaconess Hospital

Abstract

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.

Highlights

Signal Transduction Proteins That Associate with the Platelet-derivedGrowth Factor (PDGF) Receptor Mediate the PDGF-induced Release of Glucose-6-phosphate Dehydrogenase from Permeabilized Cells*
Lial cell line; HepG2, human hepatoma cell line; PI3K, phosphatidyli- In this paper,we address the earlysignal transnositol 3-kinase;rasGAP, rasGTPase activating protein;SH-2 PTPase, duction events leading to the releoafseGGPDcaused by PDGF
Tial signal mediating the releaseof GGPD is PDGFR-mediated tyrosine phosphorylation. To test this hypothesis we used two epithelial cell lines each transfected with wild type or mutant PDGFRs (Fig. 1).We have found that the PDGF-stimulated release ofGGPD: 1)requires the intrinsic tyrosine kinase activity of the PDGFR, 2) requires PDGFR autophosphorylation; and 3) is mediated by signaling proteins that associate with the PDGFR

Summary

Introduction

Signal Transduction Proteins That Associate with the Platelet-derivedGrowth Factor (PDGF) Receptor Mediate the PDGF-induced Release of Glucose-6-phosphate Dehydrogenase from Permeabilized Cells*. Cose 6-phosphatdeehydrogenase (G6PD) following Research from our laboratory has previously shown that epistimulation with peptide growth factors Chern.266,12442-12448).To evaluate the We showed that GGPD, an enzyme thought to be cytosolic, was signatlransductionpathwaysmediating release of bound to an intracellular site [4]. GGPD, two cell lines transfected with wild type or mu- the growth factors stimulated a highly significant release of tantplatelet-derivedgrowthfactor (PDGF) receptors GGPD from a n intracellular binding site [4]. The aim of the (PDGFR) werestudied using two permeabilization pro- research presented hereis to determine the initial intracellular tocols. GGPD release was evaluated by enzymeactivity signals that mediate the PDGF-stimulatedeffects on GGPD

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