Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2011-1-11
pubmed:abstractText
The Dbf4/Cdc7 kinase (DDK) plays an essential role in stimulating DNA replication by phosphorylating subunits of the Mcm2-7 helicase complex at origins. This kinase complex is itself phosphorylated and removed from chromatin in a Rad53-dependent manner when an S phase checkpoint is triggered. Comparison of Dbf4 sequence across a variety of eukaryotic species has revealed three conserved regions that have been termed motifs N, M and C. The most highly conserved of the three, motif C, encodes a zinc finger, which are known to mediate protein-protein and protein-DNA interactions. Mutation of conserved motif C cysteines and histidines disrupted the association of Dbf4 with ARS1 origin DNA and Mcm2, but not other known ligands including Cdc7, Rad53 or the origin recognition complex subunit Orc2. Furthermore, these mutations impaired the ability of Dbf4 to phosphorylate Mcm2. Budding yeast strains for which the single genomic DBF4 copy was replaced with these motif C mutant alleles were compromised for entry into and progression through S phase, indicating that the observed weakening of the Mcm2 interaction prevents DDK from efficiently stimulating the initiation of DNA replication. Following initiation, Mcm2-7 migrates with the replication fork. Interestingly, the motif C mutants were sensitive to long-term, but not short-term exposure to the genotoxic agents hydroxyurea and methyl methanesulfonate. These results support a model whereby DDK interaction with Mcm2 is important to stabilize and/or restart replication forks during conditions where a prolonged S-phase checkpoint is triggered.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1551-4005
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2018-26
pubmed:dateRevised
2011-7-5
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
The Dbf4 motif C zinc finger promotes DNA replication and mediates resistance to genotoxic stress.
pubmed:affiliation
Department of Biology, University of Waterloo, Waterloo, ON, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't