Key regulator of ligase activity of the anaphase promoting complex/cyclosome (APC/C), which confers substrate specificity upon the complex. Associates with the APC/C in late mitosis, in replacement of CDC20, and activates the APC/C during anaphase and telophase. The APC/C remains active in degrading substrates to ensure that positive regulators of the cell cycle do not accumulate prematurely. At the G1/S transition FZR1 is phosphorylated, leading to its dissociation from the APC/C. Following DNA damage, it is required for the G2 DNA damage checkpoint: its dephosphorylation and reassociation with the APC/C leads to the ubiquitination of PLK1, preventing entry into mitosis.
Subcellular location: Nucleus, Intracellular
Synonyms: FZR, CDH1, FZR2, HCDH, HCDH1, CDC20C, Fizzy-related protein homolog, CDC20-like protein 1, Cdh1/Hct1 homolog, FZR1, FYR, KIAA1242