title: Interaction between human MCM7 and Rad17 proteins is required for replication checkpoint signaling.
abstract: Human Rad17 (hRad17) is centrally involved in the activation of cell-cycle checkpoints by genotoxic agents or replication stress. Here we identify hMCM7, a core component of the DNA replication apparatus, as a novel hRad17-interacting protein. In HeLa cells, depletion of either hRad17 or hMCM7 with small-interfering RNA suppressed ultraviolet (UV) light- or aphidicolin-induced hChk1 phosphorylation, and abolished UV-induced S-phase checkpoint activation. Similar results were obtained after transfection of these cells with a fusion protein containing the hMCM7-binding region of hRad17. The hMCM7-depleted cells were also defective for the formation of ATR-containing nuclear foci after UV irradiation, suggesting that hMCM7 is required for stable recruitment of ATR to damaged DNA. These results demonstrate that hMCM7 plays a direct role in the transmission of DNA damage signals from active replication forks to the S-phase checkpoint machinery in human cells.
authors.affiliation: Program in Signal Transduction Research, Cancer Research Center, The Burnham Institute, La Jolla, CA 92037, USA.
authors.forename: Cheng-Chung
authors.initials: CC
authors.lastname: Tsao
authors.forename: Christoph
authors.initials: C
authors.lastname: Geisen
authors.forename: Robert T
authors.initials: RT
authors.lastname: Abraham
mesh_terms: D016590:Aphidicolin / Q000494:pharmacology; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D045744:Cell Line, Tumor; D000071877:Checkpoint Kinase 1; D064447:Checkpoint Kinase 2; D004249:DNA Damage; D004261:DNA Replication / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D064168:Minichromosome Maintenance Complex Component 7; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D010766:Phosphorylation; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics; D016196:S Phase / Q000502:physiology; D015398:Signal Transduction; D014162:Transfection; D020798:Two-Hybrid System Techniques; D014466:Ultraviolet Rays
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C113575:Rad17 protein, human; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D016590:Aphidicolin; D011494:Protein Kinases; D064447:Checkpoint Kinase 2; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C000605867:CHEK1 protein, human; C578634:CHEK2 protein, human; D000071877:Checkpoint Kinase 1; D017346:Protein Serine-Threonine Kinases; C101624:MCM7 protein, human; D064168:Minichromosome Maintenance Complex Component 7