Sgol2 provides a regulatory platform that coordinates essential cell cycle processes during meiosis I in oocytes

This article is distributed under the terms of the Creative Commons Attribution License.-- et al.Accurate chromosome segregation depends on coordination between cohesion resolution and kinetochore-microtubule interactions (K-fibers), a process regulated by the spindle assembly checkpoint (SAC). How these diverse processes are coordinated remains unclear. We show that in mammalian oocytes Shugoshin-like protein 2 (Sgol2) in addition to protecting cohesin, plays an important role in turning off the SAC, in promoting the congression and bi-orientation of bivalents on meiosis I spindles, in facilitating formation of K-fibers and in limiting bivalent stretching. Sgol2's ability to protect cohesin depends on its interaction with PP2A, as is its ability to silence the SAC, with the latter being mediated by direct binding to Mad2. In contrast, its effect on bivalent stretching and K-fiber formation is independent of PP2A and mediated by recruitment of MCAK and inhibition of Aurora C kinase activity respectively. By virtue of its multiple interactions, Sgol2 links many of the processes essential for faithful chromosome segregation.AR was supported by a PhD fellowship from the Boehringer Ingelheim Fonds. BM and OS were supported by a grant of the Deutsche Forschungsgemeinschaft (STE997/3-2 within the priority program SPP1384). AP was supported by SAF2011-25252. This study was funded by the European Community’s Seventh Framework MitoSys/241548, Medical Research Council and Wellcome Trust and Ministerio de Ciencia e Innovacion SAF2011-25252.Peer Reviewe