Cell Division Cycle Protein 20B (CDC20B)

AMA1/CDC20B, is required for sporulation and has been implicated as a meiosisspecific activator of APC . In fission yeast, five CDC20/CDH1 homologues can be identified. In addition to the documented CDC20A (SLP1) and CDH1A (SRW1/STE9), two CDC20 paralogues (CDC20B and CDC20C) and another CDH1 paralogue (CDH1B or MFR1 or FZR1) were found. In the phylogenetic tree, the fission yeast CDC20B and CDC20C cluster with budding yeast AMA1/CDC20B, while the fission yeast CDH1A and CDH1B group with budding yeast CDH1. CDH1B/MFR1/FZR1 has been shown to be another meiosis-specific activator of APC required for sporulation. The bootstrap supports for these clusters are statistically very significant. Arabidopsis thaliana has at least one CDH1 and three closely related CDC20 homologues (CDC20A, CDC20B and CDC20C).