Mitotic regulation of the human anaphase-promoting complex by phosphorylation

摘要: The anaphase‐promoting complex (APC) or cyclosome is a ubiquitin ligase that initiates anaphase and mitotic exit. APC activation thought to depend on phosphorylation Cdc20 binding. We have identified 43 phospho‐sites of which at least 34 are mitosis specific. Of these, 32 sites clustered in parts Apc1 the tetratricopeptide repeat (TPR) subunits Cdc27, Cdc16, Cdc23 Apc7. In vitro , 15 can be generated by cyclin‐dependent kinase 1 (Cdk1), 3 Polo‐like (Plk1). Cdk1, but not Plk1, sufficient for increased binding activation. Immunofluorescence microscopy using phospho‐antibodies indicates initiated prophase during nuclear uptake cyclin B1. prometaphase phospho‐APC accumulates centrosomes where B ubiquitination initiated, appears throughout cytosol disappears Plk1 depletion neither prevents nor A destruction vivo . These observations imply Cdk1 already nuclei late cells.