Phosphorylation of the eIF4E‐binding protein PHAS‐I after exposure of PC12 cells to EGF and NGF

FEBS Letters

Kleijn, Miranda¹  Korthout, Marsha M.R.¹  Voorma, Harry O.¹  Thomas, Adri A.M.¹ 

[1] Utrecht University, Department of Molecular Cell Biology, Padualaan 8, 3584 CH Utrecht, The Netherlands

关键词: PHAS-I;    Phosphorylation;    p70S6K;    FRAP;    PI-3 kinase;    PKC;    eIF;    eukaryotic initiation factor;    EGF;    epidermal growth factor;    FRAP;    FKBP-rapamycin associated protein;    IGF-I;    insulin-like growth factor I;    MAPK;    mitogen-activated protein kinase;    NGF;    nerve growth factor;    p70S6K;    70-kDa S6 protein kinase;    PDGF;    platelet-derived growth factor;    PHAS-I;    phosphorylated heat- and acid-stable protein induced by insulin;    PI-3 kinase;    phosphatidylinositol-3′-OH kinase;    PKC;    protein kinase C;   

DOI  :  10.1016/0014-5793(96)01097-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

PHAS-I or the eIF4E-binding protein 1 regulates the cap-binding activity of eIF4E by sequestering eIF4E. Binding of eIF4E to PHAS-I is regulated by phosphorylation of PHAS-I. PC12 cells were used to study the signal transduction pathway leading to phosphorylation of PHAS-I. Both EGF and NGF induced phosphorylation of PHAS-I. Wortmannin, a PI-3 kinase inhibitor, staurosporine, a PKC inhibitor, and rapamycin, a FRAP inhibitor all blocked the phosphorylation of PHAS-I. Of the three inhibitors, only wortmannin was able to inhibit MAPK phosphorylation. This excludes a role for MAPK in NGF- and EGF-induced PHAS-I phosphorylation in PC12 cells. Apparently, PHAS-I was phosphorylated in a PI-3 kinase-, PKC-, and FRAP-dependent manner after EGF or NGF stimulation. Only PI-3 kinase and FRAP are involved in the regulation of the basal level of PHAS-I phosphorylation.

【 授权许可】

Unknown