Cdc6

Cell division cycle 6 (CDC6) is a protein essential for the initiation of DNA replication. Its role is to recruit a complex of six proteins, called the MCM complex (minichromosome maintenance complex) to the sites of replication initiation. Cdc6 interacts with both ORC (the origin recognition complex) and the Cdt1 protein to accomplish MCM recruitment. The MCM complex has the ability to unwind the DNA helix, and activity termed helicase activity.

In mammalian cells, it localizes in the cell nucleus during cell cycle G1, and in some experimental situations translocates to the cytoplasm at the start of S phase. In normal cells it appears that Cdc6 remains nuclear throughout the cells cycle. In yeast cells, the Cdc6 protein is broken down during S phase rather than exported. In mammalian cells, Cdc6 is broken down during cell division. Cdc6 is overproduced by many types of cancer cells.