Don't Skip the G1 Phase: How APC/CCdh1 Keeps SCFSKP2 in Check

By keeping the levels of Skp2 and Cks1 low during G1 progression, APC/C^Cdh1 prevents unscheduled degradation of SCF^Skp2 substrates and premature entry into S phase. Thus, APC/C^Cdh1, a ubiquitin ligase involved in mitotic exit and maintenance of G0/G1 phase, directly controls SCF^SKP2, a ubiquitin ligase involved in the regulation of S phase entry.