CDC7

null CDC7 is the catalytic subunit of Dbf4-dependent kinase (DDK), an S-phase-activating serine/threonine kinase named for its yeast cell-division-cycle mutant. Together with the regulatory subunits DBF4 (ASK) or DRF1, CDC7 phosphorylates the MCM2-7 helicase complex and other replication factors to trigger the G1/S transition and initiation of DNA replication. CDC7 expression is cell-cycle regulated and elevated in many tumors, while normal tissues appear relatively tolerant of its inhibition, which has made CDC7/DBF4 a prominent anticancer target pursued with small-molecule inhibitors. Recombinant CDC7, with or without DBF4, supports studies of replication initiation, checkpoint signaling and DDK inhibitor screening.