Involved in the initiation of DNA replication. Also participates in checkpoint controls that ensure DNA replication is completed before mitosis is initiated. Interacts with PCNA, ORC1, cyclin-CDK (PubMed:9566895). Interacts with HUWE1 (PubMed:17567951). Interacts with ANKRD17 (PubMed:23711367). Interacts with GRWD1; origin binding of GRWD1 is dependent on CDC6 (PubMed:25990725). Interacts with CDT1; are mutually dependent on one another for loading MCM complexes onto chromatin (PubMed:14672932). Interacts with TTC4 (PubMed:18320024). Interacts (via Cy motif) with CCNF; the interaction takes place during G2 and M phase (PubMed:26818844). Interacts with CDH1 (PubMed:26818844). The protein is nuclear in G1 and cytoplasmic in S-phase cells (PubMed:9566895). Ubiquitinated by the SCF(CCNF) E3 ubiquitin-protein ligase complex. The disease is caused by variants affecting the gene represented in this entry. Belongs to the CDC6/cdc18 family.