title: Mcm2-7 Is an Active Player in the DNA Replication Checkpoint Signaling Cascade via Proposed Modulation of Its DNA Gate.
abstract: The DNA replication checkpoint (DRC) monitors and responds to stalled replication forks to prevent genomic instability. How core replication factors integrate into this phosphorylation cascade is incompletely understood. Here, through analysis of a unique mcm allele targeting a specific ATPase active site (mcm2DENQ), we show that the Mcm2-7 replicative helicase has a novel DRC function as part of the signal transduction cascade. This allele exhibits normal downstream mediator (Mrc1) phosphorylation, implying DRC sensor kinase activation. However, the mutant also exhibits defective effector kinase (Rad53) activation and classic DRC phenotypes. Our previous in vitro analysis showed that the mcm2DENQ mutation prevents a specific conformational change in the Mcm2-7 hexamer. We infer that this conformational change is required for its DRC role and propose that it allosterically facilitates Rad53 activation to ensure a replication-specific checkpoint response.
authors: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors: Feng-Ling
authors: FL
authors: Tsai
authors: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors: Sriram
authors: S
authors: Vijayraghavan
authors: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA.
authors: Joseph
authors: J
authors: Prinz
authors: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA.
authors: Heather K
authors: HK
authors: MacAlpine
authors: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA.
authors: David M
authors: DM
authors: MacAlpine
authors: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA schwacha@pitt.edu.
authors: Anthony
authors: A
authors: Schwacha
mesh_terms: D020134:Catalytic Domain; D018797:Cell Cycle Proteins / Q000378:metabolism; D064447:Checkpoint Kinase 2 / Q000378:metabolism; D004261:DNA Replication; D004271:DNA, Fungal / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D064110:Minichromosome Maintenance Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism; D055503:Protein Multimerization; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: C102209:CDC45 protein, S cerevisiae; D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D064447:Checkpoint Kinase 2; C067022:RAD53 protein, S cerevisiae; C069199:MCM2 protein, S cerevisiae; D064110:Minichromosome Maintenance Proteins