title: Mcm10 interacts with Rad4/Cut5(TopBP1) and its association with origins of DNA replication is dependent on Rad4/Cut5(TopBP1).
abstract: Initiation of DNA replication in eukaryotes is a highly conserved and ordered process involving the co-ordinated, stepwise association of distinct proteins at multiple origins of replication throughout the genome. Here, taking Schizosaccharomyces pombe as a model, the role of Rad4(TopBP1) in the assembly of the replication complex has been examined. Quantitative chromatin immunoprecipitation experiments confirm that Rad4(TopBP1) associates with origins of DNA replication and, in addition, demonstrate that the protein is not present within the active replisome. A direct interaction between Rad4(TopBP1) and Mcm10 is shown and this is reflected in the Rad4(TopBP1)-dependent origin association of Mcm10. Rad4(TopBP1) is also shown to interact with Sld2 and Sld3 and to be required for the stable origin association of these two proteins. Rad4(TopBP1) chromatin association at stalled replication forks was found to be dependent upon the checkpoint protein Rad9, which was not required for Rad4(TopBP1) origin association. Comparison of the levels of chromatin association at origins of replication and stalled replication forks and the differential requirement for Rad9 suggest functional differences for Rad4(TopBP1) at these distinct sites.
authors.affiliation: School of Health and Medicine, Division of Biomedical and Life Sciences, Biological Sciences Building, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Taylor
authors.forename: Karen
authors.initials: K
authors.lastname: Moore
authors.forename: Johanne
authors.initials: J
authors.lastname: Murray
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Aves
authors.forename: Clive
authors.initials: C
authors.lastname: Price
mesh_terms: D059447:Cell Cycle Checkpoints; D018797:Cell Cycle Proteins / Q000378:metabolism*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism*; D064110:Minichromosome Maintenance Proteins; D011485:Protein Binding / Q000502:physiology; D018741:Replication Origin; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism*; D011503:Transglutaminases / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C082463:RAD4 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; C496523:Sld3 protein, S pombe; C489609:cdc23 protein, S pombe; D011503:Transglutaminases; D064110:Minichromosome Maintenance Proteins