Q9H211

CDT1 also known as DUP is involved in the formation of the pre-replication complex that is necessary for DNA replication. CDT1 is a nuclear-localizing replication initiation factor, specifically expressed during the G1 and S phases of the cell cycle. CDT1 facilitates the loading of the minichromosome maintenance (MCM) complex onto chromatin at the end of mitosis, a critical step necessary for DNA replication initiation. While CDT1 mRNA maintains consistent expression throughout the cell cycle, CDT1 levels decrease significantly after S-phase onset, indicating proteolytic degradation′s essential role in maintaining proper levels and preventing untimely DNA replication. CDT1 also interacts with DNA replication inhibitor geminin during S and G2 phases, preventing inappropriate origin firing. CDT1′s ability to reverse geminin′s inhibition of DNA replication in cell-free extracts highlights CDT1′s significance in DNA synthesis and cell cycle progression regulation.