Involvement of protein‐tyrosine phosphorylation and dephosphorylation in sperm‐induced Xenopus egg activation

FEBS Letters

Sato, Ken-ichi¹  Tamaki, Ikuo²  Aoto, Mamoru²  Iwasaki, Tetsushi²  Tokmakov, Alexander A²  Fukami, Yasuo¹ 

[1]Laboratory of Molecular Biology, Biosignal Research Center, Kobe University, Nada, Kobe 657, Japan

[2]The Graduate School of Science and Technology, Kobe University, Nada, Kobe 657, Japan

关键词: Protein tyrosine phosphorylation/dephosphorylation;    Xenopus laevis fertilization;    Egg activation;    Genistein;    Xyk;    Xenopus tyrosine kinase;    Na3VO4;    sodium orthovanadate;    DMSO;    dimethylsulfoxide;    DB;    DeBoer's solution;    SDS-PAGE;    SDS-polyacrylamide gel electrophoresis;    MAP kinase;    mitogen-activated protein kinase;   

DOI  :  10.1016/S0014-5793(98)00123-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have analyzed tyrosine-phosphorylated proteins in Xenopus laevis eggs before and after fertilization by immunoblotting with anti-phosphotyrosine antibody. A number of egg proteins with different subcellular distribution became tyrosine-phosphorylated or dephosphorylated within 30 min after insemination. Tyrosine kinase-specific inhibitors genistein and herbimycin A were found to inhibit sperm-induced egg activation judged by the egg cortical contraction. Surprisingly, sodium orthovanadate, a tyrosine phosphatase inhibitor, also inhibited the egg activation. Moreover, we found that fertilization-dependent tyrosine dephosphorylation of 42-kDa mitogen-activated protein kinase was inhibited in genistein-treated eggs. These results suggest that both protein-tyrosine phosphorylation and dephosphorylation pathways play an important role in the sperm-induced Xenopus egg activation.

【 授权许可】

Unknown