title: Maternal PCBP1 determines the normal timing of pronucleus formation in mouse eggs.
abstract: In mammals, pronucleus formation, a landmark event for egg activation and fertilization, is critical for embryonic development. However, the mechanisms underlying pronucleus formation remain unclear. Increasing evidence has shown that the transition from a mature egg to a developing embryo and the early steps of development are driven by the control of maternal cytoplasmic factors. Herein, a two-dimensional-electrophoresis-based proteomic approach was used in metaphase II and parthenogenetically activated mouse eggs to search for maternal proteins involved in egg activation, one of which was poly(rC)-binding protein 1 (PCBP1). Phosphoprotein staining indicated that PCBP1 displayed dephosphorylation in parthenogenetically activated egg, which possibly boosts its ability to bind to mRNAs. We identified 75 mRNAs expressed in mouse eggs that contained the characteristic PCBP1-binding CU-rich sequence in the 3'-UTR. Among them, we focused on H2a.x mRNA, as it was closely related to pronucleus formation in Xenopus oocytes. Further studies suggested that PCBP1 could bind to H2a.x mRNA and enhance its stability, thus promoting mouse pronucleus formation during parthenogenetic activation of murine eggs, while the inhibition of PCBP1 evidently retarded pronucleus formation. In summary, these data propose that PCBP1 may serve as a novel maternal factor that is required for determining the normal timing of pronucleus formation.
authors.affiliation: State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, 210029, People's Republic of China.
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Shi
authors.forename: Chun
authors.initials: C
authors.lastname: Zhao
authors.forename: Ye
authors.initials: Y
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Teng
authors.forename: Ying
authors.initials: Y
authors.lastname: Guo
authors.forename: Minyue
authors.initials: M
authors.lastname: Ma
authors.forename: Xuejiang
authors.initials: X
authors.lastname: Guo
authors.forename: Zuomin
authors.initials: Z
authors.lastname: Zhou
authors.forename: Ran
authors.initials: R
authors.lastname: Huo
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism / Q000502:physiology; D003593:Cytoplasm / Q000378:metabolism / Q000502:physiology; D004268:DNA-Binding Proteins; D005260:Female; D005306:Fertilization / Q000502:physiology; D008677:Metaphase / Q000502:physiology; D051379:Mice; D008813:Mice, Inbred ICR; D009865:Oocytes / Q000378:metabolism* / Q000502:physiology*; D010312:Parthenogenesis / Q000502:physiology; D010766:Phosphorylation / Q000502:physiology; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C121375:Pcbp1 protein, mouse; D012333:RNA, Messenger; D016601:RNA-Binding Proteins