磷脂酰肌醇3激酶通过在促红细胞生成素刺激的细胞中激活PLC-γ(2)来调节糖基磷脂酰肌醇水解。

Phosphatidylinositol 3-kinase regulates glycosylphosphatidylinositol hydrolysis through PLC-gamma(2) activation in erythropoietin-stimulated cells.

作者信息

Boudot Cédric, Kadri Zahra, Petitfrère Emmanuelle, Lambert Elise, Chrétien Stany, Mayeux Patrick, Haye Bernard, Billat Claudine

机构信息

Laboratoire de Biochimie, CNRS, FRE 2534, IFR 53 Biomolécules, UFR Sciences Exactes et Naturelles, BP 1039, Université de Reims Champagne-Ardenne, 51687 Reims Cedex 2, France.

出版信息

Cell Signal. 2002 Oct;14(10):869-78. doi: 10.1016/s0898-6568(02)00036-0.

DOI:10.1016/s0898-6568(02)00036-0

PMID:12135708

Abstract

Erythropoietin (Epo)-induced glycosylphosphatidylinositol (GPI) hydrolysis was previously described to be correlated with phospholipase C-gamma 2 (PLC-gamma2) activation. Here, we analyzed the involvement of phosphatidylinositol (PtdIns) 3-kinase in GPI hydrolysis through PLC-gamma2 tyrosine phosphorylation in response to Epo in FDC-P1 cells transfected with a wild type (WT) erythropoietin-receptor (Epo-R). We showed that phosphatidylinositol 3-kinase (PtdIns 3-kinase) inhibitor LY294002 inhibits Epo-induced hydrolysis of endogenous GPI and Epo-induced PLC-gamma2 tyrosine phosphorylation in a dose-dependent manner. Wortmannin, another PtdIns 3-kinase inhibitor, also suppressed Epo-induced PLC-gamma2 tyrosine phosphorylation. We also present evidence that PLC-gamma2 translocation to the membrane fraction on Epo stimulation is completely inhibited by LY294002. Upon Epo stimulation, the tyrosine-phosphorylated PLC-gamma2 was found to be associated with the tyrosine-phosphorylated Grb2-associated binder (GAB)2, SHC and SHP2 proteins. LY294002 cell preincubation did not affect GAB2, SHC and SHP2 tyrosine phosphorylation but inhibited the binding of PLC-gamma2 to GAB2 and SHP2. Taken together, these results show that PtdIns 3-kinase controls Epo-induced GPI hydrolysis through PLC-gamma2.

摘要

促红细胞生成素（Epo）诱导的糖基磷脂酰肌醇（GPI）水解先前已被描述与磷脂酶C-γ2（PLC-γ2）激活相关。在此，我们通过在转染野生型（WT）促红细胞生成素受体（Epo-R）的FDC-P1细胞中，响应Epo时PLC-γ2酪氨酸磷酸化，分析了磷脂酰肌醇（PtdIns）3-激酶在GPI水解中的作用。我们发现，磷脂酰肌醇3-激酶（PtdIns 3-激酶）抑制剂LY294002以剂量依赖的方式抑制Epo诱导的内源性GPI水解和Epo诱导的PLC-γ2酪氨酸磷酸化。另一种PtdIns 3-激酶抑制剂渥曼青霉素也抑制Epo诱导的PLC-γ2酪氨酸磷酸化。我们还提供证据表明，LY294002完全抑制了Epo刺激下PLC-γ2向膜部分的转位。在Epo刺激后，发现酪氨酸磷酸化的PLC-γ2与酪氨酸磷酸化的Grb2相关结合蛋白（GAB）2、SHC和SHP2蛋白相关。LY294002细胞预孵育不影响GAB2、SHC和SHP2的酪氨酸磷酸化，但抑制PLC-γ2与GAB2和SHP2的结合。综上所述，这些结果表明PtdIns 3-激酶通过PLC-γ2控制Epo诱导的GPI水解。