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Successive recruitment of p‐CDC25B‐Ser351 and p‐cyclin B1‐Ser123 to centrosomes contributes to the release of mouse oocytes from prophase I arrest
Author(s) -
Zhao Xiangyu,
Feng Chen,
Yu Dahai,
Deng Xin,
Wu Didi,
Jin Minglin,
Wang Enhua,
Wang Xiuxia,
Yu Bingzhi
Publication year - 2015
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.24220
Subject(s) - biology , cyclin b1 , microbiology and biotechnology , germinal vesicle , prophase , cyclin b , metaphase , centrosome , cyclin a , cyclin , cyclin a2 , cyclin dependent kinase 1 , meiosis , phosphorylation , cell cycle , genetics , oocyte , cyclin dependent kinase 2 , protein kinase a , chromosome , embryo , apoptosis , gene
Background: The molecular mechanism that controls the activation of Cyclin B1‐CDK1 complex has been widely investigated. It is generally believed that CDC25B acts as a “starter phosphatase” of mitosis. In this study, we investigate the sequential regulation of meiotic resumption by CDC25B and Cyclin B1 in mouse oocytes. Results: Injection of mRNAs coding for CDC25B‐Ser351A and/or Cyclin B1‐Ser123A shows a more potent maturation‐inhibiting ability than their respective wild type. Co‐injection of mRNAs coding for phosphor‐mimic CDC25B‐Ser351D and Cyclin B1‐Ser123D can rescue this prophase I arrest induced by CDC25B‐Ser351A or Cyclin B1‐Ser123A. In addition, p‐CDC25B‐Ser351 is co‐localized at the microtubule‐organizing centers (MTOCs) with Aurora kinase A (AURKA) during maturation and p‐Cyclin B1‐Ser123 is only captured on MTOCs shortly before germinal vesicle breakdown (GVBD). Depletion of AURKA not only resulted in metaphase I (MI) spindle defects and anaphase I (AI) abnormal chromosomes separation but also prevented the phosphorylation of CDC25B‐Ser351 at centrosomes. AURKA depletion induced deficiencies of spindle assembly and progression to MII can be rescued by CDC25B‐Ser351D mRNA injection. Conclusions: AURKA induced phosphorylation and recruitment of CDC25B to MTOCs prior to p‐Cyclin B1‐Ser123, and this sequential regulation is essential for the commitment of the oocytes to resume meiosis. Developmental Dynamics 244:110–121, 2015 . © 2014 Wiley Periodicals, Inc.