Sheu YJ and Stillman B (2006) Cdc7-Dbf4 phosphorylates MCM proteins via a docking site-mediated mechanism to promote S phase progression. Mol Cell 24(1):101-13
Abstract: Origins of DNA replication are licensed in G1 by recruiting the minichromosome maintenance (MCM) proteins to form a prereplicative complex (pre-RC). Prior to initiation of DNA synthesis from each origin, a preinitiation complex (pre-IC) containing Cdc45 and other proteins is formed. We report that Cdc7-Dbf4 protein kinase (DDK) promotes assembly of a stable Cdc45-MCM complex exclusively on chromatin in S phase. In this complex, Mcm4 is hyperphosphorylated. Studies in vitro using purified DDK and Mcm4 demonstrate that hyperphosphorylation occurs at the Mcm4 N terminus. However, the DDK substrate specificity is conferred by an adjacent DDK-docking domain (DDD), sufficient for facilitating efficient phosphorylation of artificial phosphoacceptors in cis. Genetic evidence suggests that phosphorylation of Mcm4 by DDK is important for timely S phase progression and for cell viability upon overproduction of Cdc45. We suggest that DDK docks on and phosphorylates MCM proteins at licensed origins to promote proper assembly of pre-IC.
|Status: Published||Type: Journal Article | Research Support, N.I.H., Extramural | Research Support, Non-U.S. Gov't||PubMed ID: 17018296|
Topics addressed in this paper
Number of different genes curated to this paper: 9
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|Cell Cycle Phase Involved|
|Protein Sequence Features|