Cytoplasmic ATR activation promotes vaccinia virus genome replication
journal contributionposted on 19.10.2020, 14:37 by Antonio Postigo, Amy E Ramsden, Michael Howell, Michael Way
In contrast to most DNA viruses, poxviruses replicate their genomes in the cytoplasm without host involvement. We find that vaccinia virus induces cytoplasmic activation of ATR early during infection, before genome uncoating, which is unexpected because ATR plays a fundamental nuclear role in maintaining host genome integrity. ATR, RPA, INTS7, and Chk1 are recruited to cytoplasmic DNA viral factories, suggesting canonical ATR pathway activation. Consistent with this, pharmacological and RNAi-mediated inhibition of canonical ATR signaling suppresses genome replication. RPA and the sliding clamp PCNA interact with the viral polymerase E9 and are required for DNA replication. Moreover, the ATR activator TOPBP1 promotes genome replication and associates with the viral replisome component H5. Our study suggests that, in contrast to long-held beliefs, vaccinia recruits conserved components of the eukaryote DNA replication and repair machinery to amplify its genome in the host cytoplasm.
ATRChk1DNA replicationPCNARPAvaccinia virusviral replisomeAnimalsAtaxia Telangiectasia Mutated ProteinsCarrier ProteinsCell LineCheckpoint Kinase 1Chlorocebus aethiopsDNA-Binding ProteinsGenome, ViralHeLa CellsHost-Pathogen InteractionsHumansNuclear ProteinsProliferating Cell Nuclear AntigenReplication Protein AVaccinia virusVirus ReplicationHela CellsCercopithecus aethiopsWay FC001209HTS0601 Biochemistry and Cell Biology