The regulation of CDT1 is critical for maintaining genomic stability. CDT1 activity is tightly controlled throughout the cell cycle by multiple mechanisms:
Geminin: During the S, G2, and early M phases, CDT1 is inhibited by geminin, a protein that binds to CDT1 and prevents it from loading the MCM complex. Proteolysis: CDT1 is targeted for degradation by the ubiquitin-proteasome system. In response to DNA damage, CDT1 is rapidly degraded to prevent re-replication of damaged DNA. Phosphorylation: Post-translational modifications, such as phosphorylation, also play a role in the temporal regulation of CDT1 activity.
