title: Distinct subcellular localization and potential role of LINE1-ORF1P in meiotic oocytes.
abstract: LINE-1 is an autonomous non-LTR retrotransposon in mammalian genomes and encodes ORF1P and ORF2P. ORF2P has been clearly identified as the enzyme supplier needed in LINE-1 retrotransposition. However, the role of ORF1P is not well explored. In this study, we employed loss/gain-of-function approach to investigate the role of LINE1-ORF1P in mouse oocyte meiotic maturation. During mouse oocyte development, ORF1P was observed in cytoplasm as well as in nucleus at germinal vesicle (GV) stage while was localized on the spindle after germinal vesicle breakdown (GVBD). Depletion of ORF1P caused oocyte arrest at the GV stage as well as down-regulation of CDC2 and CYCLIN B1, components of the maturation-promoting factor (MPF). Further analysis demonstrated ORF1P depletion triggered DNA damage response and most of the oocytes presented altered chromatin configuration. In addition, SMAD4 showed nuclear foci signal after Orf1p dsRNA injection. ORF1P overexpression held the oocyte development at MI stage and the chromosome alignment and spindle organization were severely affected. We also found that ORF1P could form DCP1A body-like foci structure in both cytoplasm and nucleus after heat shock. Taken together, accurate regulation of ORF1P plays an essential role in mouse oocyte meiotic maturation.
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Beijing, China.|Department of Animal Science, Chungbuk National University, Cheongju, Korea.
authors.forename: Yi-Bo
authors.initials: YB
authors.lastname: Luo
authors.affiliation: Hebei Key Laboratory of Animal Science, Hebei Medical University, Shijiazhuang, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Animal Science, Chungbuk National University, Cheongju, Korea.
authors.forename: Zi-Li
authors.initials: ZL
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Beijing, China.
authors.forename: Jun-Yu
authors.initials: JY
authors.lastname: Ma
authors.affiliation: Department of Animal Science, Chungbuk National University, Cheongju, Korea.
authors.forename: Jialin
authors.initials: J
authors.lastname: Jia
authors.affiliation: Department of Animal Science, Chungbuk National University, Cheongju, Korea.
authors.forename: Suk
authors.initials: S
authors.lastname: Namgoong
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Beijing, China. sunqy@ioz.ac.cn.
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Sun
mesh_terms: D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D056744:Cyclin B1 / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics; D004722:Endoribonucleases / Q000378:metabolism; D005260:Female; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics*; D016200:Maturation-Promoting Factor / Q000378:metabolism; D008540:Meiosis / Q000235:genetics*; D000090204:Mesothelin; D051379:Mice; D008813:Mice, Inbred ICR; D009865:Oocytes / Q000166:cytology*; D009866:Oogenesis / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D051901:Smad4 Protein / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism
chemical_list: C534700:Ccnb1 protein, mouse; D056744:Cyclin B1; C561286:ECAT11 protein, mouse; C000715528:Msln protein, mouse; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D051901:Smad4 Protein; C490810:Smad4 protein, mouse; D015534:Trans-Activators; D016203:CDC2 Protein Kinase; D016200:Maturation-Promoting Factor; D004722:Endoribonucleases; C466280:smad4-interacting protein SMIF, mouse; D000090204:Mesothelin
keywords: DCP1A-body; LINE-1; ORF1P; Oocyte meiotic maturation; SMAD4