Abstract
During cell division, a balance between protein kinases and phosphatases is required to achieve specific and highly regulated phosphorylation levels. Protein Phosphatase 2A (PP2A) is a heterotrimeric enzyme composed of Scaffold (A), Catalytic (C), and Regulatory (B) subunits. PP2A can be targeted to different locations by specific interactions with one of several possible B subunits. B56-type subunits play important roles during meiosis in yeast and mice, including the protection of centromeric cohesion (targeted by Shugoshin) and kinetochore-microtubule attachments (targeted by BubR1). Protection of sister chromatid cohesion during meiosis I in Caenorhabditis elegans (C. elegans) does not involve the classic Shugoshin-dependent pathway and the C. elegans BubR1 orthologue Mad3SAN-1 lacks the PP2A-recruiting domain. We exploited these features to address the role(s) and regulation of PP2A:B56 during C. elegans oocyte meiosis. We report here that PP2A:B56 is recruited to chromosomes and spindle and is essential for proper chromosome segregation during oocyte meiosis in C. elegans. Recruitment of PP2A:B56 is regulated temporally and spatially by the kinase BUB-1 and is dependent on a previously unrecognised LxxIxE short linear motif (SLiM) in BUB-1. Our results highlight a novel, BUB-1-dependent mechanism for PP2A:B56 recruitment, essential for proper chromosome segregation during meiosis I.
Competing Interest Statement
The authors have declared no competing interest.
