摘要
目的:研究小鼠卵母细胞G2期阻滞中,蛋白激酶A(PKA)的候选底物及靶位点。方法:将野生型和突变型(S321A)cdc25B克隆至pBluescriptSK载体中,体外转录成mRNA,显微注射到dbcAMP处理和未处理的卵母细胞中,观察减数分裂恢复情况。结果:在小鼠卵母细胞减数分裂过程中,Cdc25B能促进减数分裂的重新启动,其突变体(S321A)能完全解除PKA引起的G2期阻滞,完成减数分裂。结论:PKA通过Cdc25B的321位丝氨酸磷酸化修饰引起G2期阻滞,PKA/Cdc25B通路在小鼠卵母细胞减数分裂中发挥重要作用。
Objective: To locate the physiological substrates and target sites of protein kinase A (PKA) in G2arrest of mouse oocytes. Methods: Wild-type (WT) and S321A cdc25B were cloned and inserted into the vectorpBluescript SK, transcribed into mRNA in vitro and then microinjected into GV-stage mouse oocytes, which weretreated with or without dbcAMP to observe the meiosis resumption. Results: Cdc25B could induce the meiosismaturation of mouse oocytes in the process of meiosis. Cdc25B-S321A mutant bypassed the ability of PKA tomaintain oocytes in G2 arrest. It induced the oocytes to resume meiosis and emit the first polar body normally.However, the wild-type Cdc25B can not bypass the inhibitory effect of PKA. Conclusion: PKA can maintain the G2arrest of mouse oocytes through the phosphorylation of Cdc25B-Serine321. PKA/Cdc25B pathway plays essentialrole in meiosis resumption.
出处
《生殖与避孕》
CAS
CSCD
北大核心
2005年第4期195-200,共6页
Reproduction and Contraception
基金
国家重点基础研究发展规划项目(973) (G1999055900-2)
国家自然科学基金重点项目(39730460)资助
