title: The cellular Mre11 protein interferes with adenovirus E4 mutant DNA replication.
abstract: Adenovirus type 5 (Ad5) relocalizes and degrades the host DNA repair protein Mre11, and efficiently initiates viral DNA replication. Mre11 associates with Ad E4 mutant DNA replication centers and is important for concatenating viral genomes. We have investigated the role of Mre11 in the E4 mutant DNA replication defect. RNAi-mediated knockdown of Mre11 dramatically rescues E4 mutant DNA replication in cells that do or do not concatenate viral genomes, suggesting that Mre11 inhibits DNA replication independent of genome concatenation. The mediator of DNA damage checkpoint 1 (Mdc1) protein is involved in recruiting and sustaining Mre11 at sites of DNA damage following ionizing radiation. We observe foci formation by Mdc1 in response to viral infection, indicating that this damage response protein is activated. However, knockdown of Mdc1 does not prevent Mre11 from localizing at viral DNA replication foci or rescue E4 mutant DNA replication. Our results are consistent with a model in which Mre11 interferes with DNA replication when it is localized at viral DNA replication foci.
authors.affiliation: Department of Microbiology, 32 Pearson Hall, Miami University, Oxford OH 45056, USA.
authors.forename: Shomita S
authors.initials: SS
authors.lastname: Mathew
authors.forename: Eileen
authors.initials: E
authors.lastname: Bridge
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000256:Adenoviridae / Q000235:genetics / Q000254:growth & development*; D018797:Cell Cycle Proteins; D004261:DNA Replication / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D000076228:MRE11 Homologue Protein; D008856:Microscopy, Fluorescence; D009687:Nuclear Proteins / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D014779:Virus Replication / Q000235:genetics*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C413163:MDC1 protein, human; C121766:MRE11 protein, human; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; D015534:Trans-Activators; D000076228:MRE11 Homologue Protein