Background：Deubiquitinase that antagonizes the anaphase-promoting complex(APC/C) during G1/S transition by mediating deubiquitination of cyclin-A(CCNA1 and CCNA2), thereby promoting S phase entry. Specifically mediates deubiquitination of 'Lys-11'-linked polyubiquitin chains, a specific ubiquitin-linkage type mediated by the APC/C complex. Also mediates deubiquitination of 'Lys-48'-linked polyubiquitin chains in vitro. Phosphorylation at Ser-628 during G1/S phase maximizes the deubiquitinase activity, leading to prevent degradation of cyclin-A(CCNA1 and CCNA2).
