Meiotic control of the APC/C: similarities & differences from mitosis

The anaphase promoting complex is a highly conserved E3 ligase complex that mediates the destruction of key regulatory proteins during both mitotic and meiotic divisions. In order to maintain ploidy, this destruction must occur after the regulatory proteins have executed their function. Thus, the regulation of APC/C activity itself is critical for maintaining ploidy during all types of cell divisions. During mitotic cell division, two conserved activator proteins called Cdc20 and Cdh1 are required for both APC/C activation and substrate selection. However, significantly less is known about how these proteins regulate APC/C activity during the specialized meiotic nuclear divisions. In addition, both budding yeast and flies utilize a third meiosis-specific activator. In Saccharomyces cerevisiae, this meiosis-specific activator is called Ama1. This review summarizes our knowledge of how Cdc20 and Ama1 coordinate APC/C activity to regulate the meiotic nuclear divisions in yeast.