title: Formation of a preinitiation complex by S-phase cyclin CDK-dependent loading of Cdc45p onto chromatin.
abstract: Cdc45p, a protein essential for initiation of DNA replication, associates with chromatin after "start" in late G1 and during the S phase of the cell cycle. Binding of Cdc45p to chromatin depends on Clb-Cdc28 kinase activity as well as functional Cdc6p and Mcm2p, which suggests that Cdc45p associates with the prereplication complex after activation of S-phase cyclin-dependent kinases (CDKs). As indicated by the timing and the CDK dependence, binding of Cdc45p to chromatin is crucial for commitment to initiation of DNA replication. During S phase, Cdc45p physically interacts with minichromosome maintenance (MCM) proteins on chromatin; however, dissociation of Cdc45p from chromatin is slower than that of MCMs, which indicates that the proteins are released by different mechanisms.
authors.affiliation: Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
authors.forename: L
authors.initials: L
authors.lastname: Zou
authors.forename: B
authors.initials: B
authors.lastname: Stillman
mesh_terms: D017489:CDC28 Protein Kinase, S cerevisiae / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D016213:Cyclins / Q000378:metabolism; D004261:DNA Replication; D004271:DNA, Fungal / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation; D005656:Fungal Proteins / Q000378:metabolism; D016193:G1 Phase; D009687:Nuclear Proteins / Q000378:metabolism*; D051738:Origin Recognition Complex; D016196:S Phase; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
chemical_list: C102209:CDC45 protein, S cerevisiae; C066503:CDC6 protein, S cerevisiae; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D016213:Cyclins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009687:Nuclear Proteins; D051738:Origin Recognition Complex; D029701:Saccharomyces cerevisiae Proteins; D017489:CDC28 Protein Kinase, S cerevisiae; D018844:Cyclin-Dependent Kinases; C069199:MCM2 protein, S cerevisiae