XGef is a CPEB-interacting protein involved in Xenopus oocyte maturation.
XGef is a CPEB-interacting protein involved in Xenopus oocyte maturation.
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XGef 是一种参与非洲爪蟾卵母细胞成熟的 CPEB 相互作用蛋白。
DOI：
10.1016/s0012-1606(02)00089-1
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发表时间：
2003
影响因子：
2.7
通讯作者：
Hake,LauraE
中科院分区：
文献类型：
--
作者：
Reverte,CarlosG;Yuan,Lei;Keady,BrianT;Lacza,Charlemagne;Attfield,KathleenR;Mahon,GwendolynM;Freeman,Benjamin;Whitehead,IanP;Hake,LauraE
XGef是在筛选与CPEB相互作用的蛋白质中分离出来的，CPEB是非洲爪蟾早期发育中mRNA翻译的调节因子。XGef是Rho家族鸟嘌呤核苷酸交换因子，在哺乳动物细胞中激活Cdc 42。内源性XGef（58 kDa）与重组CPEB相互作用，重组XGef与非洲爪蟾卵母细胞中的内源性CPEB相互作用。XGef抗体注射到第VI阶段非洲爪蟾卵母细胞阻断甾酮诱导的卵母细胞成熟，并防止多聚腺苷酸化和翻译的c-mos mRNA;注射XGef拯救这些事件。XGef在卵母细胞中的过表达加速了孕酮诱导的卵母细胞成熟和c-mos mRNA的多聚腺苷酸化和翻译。保留与CPEB相互作用能力的XGef的核苷酸交换缺陷版本的过表达不再加速卵母细胞成熟或Mos合成，表明XGef交换因子活性是过表达XGef对卵母细胞成熟的影响所必需的。XGef过表达在Mos蛋白不存在的情况下继续加速c-mos多聚腺苷酸化，但不刺激MAPK磷酸化、MPF活化或卵母细胞成熟，表明XGef可能通过Mos途径影响卵母细胞成熟。这些结果表明，XGef可能是胆固醇诱导的卵母细胞成熟途径的早期作用成分。
XGef was isolated in a screen for proteins interacting with CPEB, a regulator of mRNA translation in early Xenopus development. XGef is a Rho-family guanine nucleotide exchange factor and activates Cdc42 in mammalian cells. Endogenous XGef (58 kDa) interacts with recombinant CPEB, and recombinant XGef interacts with endogenous CPEB in Xenopus oocytes. Injection of XGef antibodies into stage VI Xenopus oocytes blocks progesterone-induced oocyte maturation and prevents the polyadenylation and translation of c-mos mRNA; injection of XGef rescues these events. Overexpression of XGef in oocytes accelerates progesterone-induced oocyte maturation and the polyadenylation and translation of c-mos mRNA. Overexpression of a nucleotide exchange deficient version of XGef, which retains the ability to interact with CPEB, no longer accelerates oocyte maturation or Mos synthesis, suggesting that XGef exchange factor activity is required for the influence of overexpressed XGef on oocyte maturation. XGef overexpression continues to accelerate c-mos polyadenylation in the absence of Mos protein, but does not stimulate MAPK phosphorylation, MPF activation, or oocyte maturation, indicating that XGef may function through the Mos pathway to influence oocyte maturation. These results suggest that XGef may be an early acting component of the progesterone-induced oocyte maturation pathway.