The PP2A Inhibitor I2PP2A Is Essential for Sister Chromatid Segregation in Oocyte Meiosis II - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Current Biology - CB Année : 2013

The PP2A Inhibitor I2PP2A Is Essential for Sister Chromatid Segregation in Oocyte Meiosis II

Jean-Philippe Chambon
  • Fonction : Auteur
Sandra A. Touati
  • Fonction : Auteur
Stephane Berneau
  • Fonction : Auteur
Celine Hebras
  • Fonction : Auteur
Rachel Groeme
  • Fonction : Auteur
Alex Mcdougall
Katja Wassmann
  • Fonction : Auteur

Résumé

Haploid gametes are generated through two consecutive meiotic divisions, with the segregation of chromosome pairs in meiosis 1 and sister chromatids in meiosis II. Separase-mediated stepwise removal of cohesion, first from chromosome arms and later from the centromere region, is a prerequisite for maintaining sister chromatids together until their separation in meiosis II [1]. In all model organisms, centromeric cohesin is protected from separase-dependent removal in meiosis 1 through the activity of PP2A-B56 phosphatase, which is recruited to centromeres by shugoshin/MEI-S332 (Sgo) [2-5]. How this protection of centromeric cohesin is removed in meiosis 11 is not entirely clear; we find that all the PP2A subunits remain colocalized with the cohesin subunit Rec8 at the centromere of metaphase II chromosomes. Here, we show that sister chromatid separation in oocytes depends on a PP2A inhibitor, namely I2PP2A. I2PP2A colocalizes with the PP2A enzyme at centromeres at metaphase 11, independently of bipolar attachment. When I2PP2A is depleted, sister chromatids fail to segregate during meiosis II. Our findings demonstrate that in oocytes I2PP2A is essential for faithful sister chromatid segregation by mediating deprotection of centromeric cohesin in meiosis II.

Dates et versions

hal-01539613 , version 1 (15-06-2017)

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Citer

Jean-Philippe Chambon, Sandra A. Touati, Stephane Berneau, Damien Cladiere, Celine Hebras, et al.. The PP2A Inhibitor I2PP2A Is Essential for Sister Chromatid Segregation in Oocyte Meiosis II. Current Biology - CB, 2013, 23 (6), pp.485-490. ⟨10.1016/j.cub.2013.02.004⟩. ⟨hal-01539613⟩
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