title: SUMO-1 plays crucial roles for spindle organization, chromosome congression, and chromosome segregation during mouse oocyte meiotic maturation.
abstract: Small ubiquitin-related modifier-1 (SUMO-1)-dependent modifications of many target proteins are involved in a range of intracellular processes. Previous studies reported the localization of SUMO-1 during oocyte meiosis, and that overexpression of Sentrin/SUMO-specific protease 2 (SENP2), a de-SUMOylation protease, altered SUMO-modified proteins, and caused defects in metaphase-II spindle organization. In this study, we detailed the consequences of SUMO-1-mediated SUMOylation by either inhibition of SUMO-1 or UBC9 with a specific antibody or their depletion by specific siRNA microinjection. Inhibition or depletion of SUMO-1 or UBC9 in germinal vesicle (GV)-stage oocytes decreased the rates of germinal vesicle breakdown and first polar body (PB1) extrusion; caused defective spindle organization and misaligned chromosomes; and led to aneuploidy in matured oocytes. Stage-specific antibody injections suggested that SUMO-1 functions before anaphase I during PB1 extrusion. Further experiments indicated that the localization of γ-tubulin was disordered after SUMO-1 inhibition, and that SUMO-1 depletion disrupted kinetochore-microtubule attachment at metaphase I. Moreover, SUMO-1 inhibition resulted in less-condensed chromosomes, altered localization of REC8 and securin, and reduced BUBR1 accumulation at the centromere. On the other hand, overexpression of SUMO-1 in GV-stage oocytes had no significant effect on oocyte maturation. In conclusion, our results implied that SUMO-1 plays crucial roles during oocyte meiotic maturation, specifically involving spindle assembly and chromosome behavior, by regulating kinetochore-microtubule attachment and the localization of γ-tubulin, BUBR1, REC8, and securin.
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, People's Republic of China.
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Yuan
authors.forename: Rui
authors.initials: R
authors.lastname: Zhai
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Liu
authors.forename: Hamid Ali
authors.initials: HA
authors.lastname: Khan
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Zhen
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Huo
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D020090:Chromosome Segregation / Q000502:physiology*; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism; D009865:Oocytes / Q000502:physiology*; D010750:Phosphoproteins / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D025842:SUMO-1 Protein / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D064249:Securin / Q000378:metabolism; D008941:Spindle Apparatus / Q000502:physiology*; D058207:Sumoylation; D014404:Tubulin / Q000378:metabolism
chemical_list: C584278:Bub1b protein, mouse; D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; C578005:PTTG1 protein, mouse; D010750:Phosphoproteins; D034741:RNA, Small Interfering; C465863:Rec8 protein, mouse; D025842:SUMO-1 Protein; D064249:Securin; D014404:Tubulin; D017346:Protein Serine-Threonine Kinases