The function of CCNF (cyclin F, ENSG00000162063) is as follows. Substrate recognition component of a SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins (PubMed:20596027, PubMed:22632967, PubMed:26818844, PubMed:27080313, PubMed:27653696, PubMed:28852778). The SCF(CCNF) E3 ubiquitin-protein ligase complex is an integral component of the ubiquitin proteasome system (UPS) and links proteasome degradation to the cell cycle (PubMed:20596027, PubMed:26818844, PubMed:27653696, PubMed:8706131). Mediates the substrate recognition and the proteasomal degradation of various target proteins involved in the regulation of cell cycle progression and in the maintenance of genome stability (PubMed:20596027, PubMed:22632967, PubMed:26818844, PubMed:27653696). Mediates the ubiquitination and proteasomal degradation of CP110 during G2 phase, thereby acting as an inhibitor of centrosome reduplication (PubMed:20596027). In G2, mediates the ubiquitination and subsequent degradation of ribonucleotide reductase RRM2, thereby maintaining a balanced pool of dNTPs and genome integrity (PubMed:22632967). In G2, mediates the ubiquitination and proteasomal degradation of CDC6, thereby suppressing DNA re-replication and preventing genome instability (PubMed:26818844). Involved in the ubiquitination and degradation of the substrate adapter CDH1 of the anaphase-promoting complex (APC/C), thereby acting as an antagonist of APC/C in regulating G1 progression and S phase entry (PubMed:27653696). May play a role in the G2 cell cycle checkpoint control after DNA damage, possibly by promoting the ubiquitination of MYBL2/BMYB (PubMed:25557911). {ECO:0000269|PubMed:20596027, ECO:0000269|PubMed:22632967, ECO:0000269|PubMed:25557911, ECO:0000269|PubMed:26818844, ECO:0000269|PubMed:27080313, ECO:0000269|PubMed:27653696, ECO:0000269|PubMed:28852778, ECO:0000269|PubMed:8706131}.