title: Inherent Instability of Correct Kinetochore-Microtubule Attachments during Meiosis I in Oocytes.
abstract: A model for mitosis suggests that correct kinetochore-microtubule (KT-MT) attachments are stabilized by spatial separation of the attachment sites from Aurora B kinase through sister KT stretching. However, the spatiotemporal regulation of attachment stability during meiosis I (MI) in oocytes remains unclear. Here, we found that in mouse oocytes, Aurora B and C (B/C) are located in close proximity to KT-MT attachment sites after bivalent stretching due to an intrinsic property of the MI chromosomes. The Aurora B/C activity destabilizes correct attachments while allowing a considerable amount of incorrect attachments to form. KT-MT attachments are eventually stabilized through KT dephosphorylation by PP2A-B56 phosphatase, which is progressively recruited to KTs depending on the BubR1 phosphorylation resulting from the timer Cdk1 and independent of bivalent stretching. Thus, oocytes lack a mechanism for coordinating bivalent stretching and KT phosphoregulation during MI, which may explain the high frequency of KT-MT attachment errors.
authors.affiliation: Laboratory for Chromosome Segregation, RIKEN Center for Developmental Biology, Kobe 650-0047, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: Laboratory for Chromosome Segregation, RIKEN Center for Developmental Biology, Kobe 650-0047, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Kaido
authors.affiliation: Laboratory for Chromosome Segregation, RIKEN Center for Developmental Biology, Kobe 650-0047, Japan. Electronic address: tkitajima@cdb.riken.jp.
authors.forename: Tomoya S
authors.initials: TS
authors.lastname: Kitajima
mesh_terms: D000818:Animals; D064107:Aurora Kinase B / Q000378:metabolism; D064108:Aurora Kinase C / Q000378:metabolism; D016203:CDC2 Protein Kinase / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D020090:Chromosome Segregation; D005260:Female; D005455:Fluorescent Antibody Technique; D007091:Image Processing, Computer-Assisted; D018386:Kinetochores / Q000502:physiology*; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D008870:Microtubules / Q000502:physiology*; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation; D054648:Protein Phosphatase 2 / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism
chemical_list: C584278:Bub1b protein, mouse; D018797:Cell Cycle Proteins; D064107:Aurora Kinase B; D064108:Aurora Kinase C; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; C551901:Ppp2r5a protein, mouse; D054648:Protein Phosphatase 2