Balance of polo-like kinase Plo1 and monopolar attachment protein 1 (Moa1) regulates fission yeast meiosis.

During meiosis, diploid germ cells undergo two successive rounds of chromosome segregation requiring key changes that sister chromatids co-orient in meiosis I and bi-orient in meiosis II. The kinetochore protein MEIKIN/Moa1 is restricted to meiosis I, has the function to properly co-orient sister kinetochores and maintain pericentrometic cohesion. However, the mechanisms governing the Moa1 activity throughout meiosis remain elusive in Schizosaccharomyces pombe. Here, we demonstrate that fission yeast Moa1 is degraded by the APC/C at anaphase I and blocking Moa1 degradation has no effect on cohesin protection and chromosome segregation during meiosis. Blocking Moa1 degradation can be prevented by the elimination of kinetochore Plo1. Conversely, the removal of Plo1 from the kinetochore, which leads to chromosome mis-segregation, can be reversed by maintaining kinetochore Moa1 levels. Therefore, we have observed a feedback relationship between reduced Plo1 enrichment at kinetochores and inhibited Moa1 degradation.