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Pott, D. M.

Publications and source records attributed to Pott, D. M..

3 recordsLinked to original sources

Selective repurposing of the eukaryotic DNA replication machinery by a plant virus

Eukaryotic DNA viruses that replicate in the nucleus often exploit components of the host DNA replication machinery for genome replication. Geminiviruses, causal agents of devastating crop diseases worldwide, strictly depend on host factors to replicate their circular single-stranded (ss) DNA genomes, with only a single virus-encoded protein, Rep, required for this process. Rep recruits host replication proteins to the viral genome and catalyzes nicking and ligation at the initiation and termination sites of rolling-circle replication. Despite the reliance of geminiviral replication on plant proteins, the composition of the viral replisome remains largely unknown. Here, we use TurboID-based proximity labeling to identify plant proteins in the vicinity of the Rep proteins from the geminiviruses tomato yellow leaf curl virus (TYLCV) and abutilon mosaic virus (AbMV) during infection. Combining virus-induced gene silencing, infection assays, and chromatin immunoprecipitation, we identify host DNA replication-related factors required for viral genome replication and likely components of the viral replisome. Our results indicate that geminiviruses and related eukaryotic ssDNA viruses selectively repurpose components of the eukaryotic replication fork to support rolling-circle replication, and suggest that they follow a leading-strand replication mode while utilizing the lagging-strand DNA polymerase {delta}. These findings shed light on the molecular mechanism of geminiviral DNA replication and identify potential targets for engineering antiviral resistance in crops.

plant biology↗

Alternative splicing expands the functional portfolio of a plant virus to control the viral cycle

Viruses frequently have limited coding space, yet efficiently manipulate complex hosts by deploying intricate, often poorly understood strategies. Geminiviruses, devastating plant pathogens with small single-stranded (ss) DNA genomes, replicate in the nucleus aided by the viral replication-associated protein (Rep), the most conserved protein within this family and related ssDNA viruses. Rep initiates viral DNA replication and represses its own promoter to regulate the infection cycle. The molecular mechanisms enabling this dual functionality are so far unknown. Here, we show that the geminivirus tomato yellow leaf curl virus (TYLCV) exploits the host spliceosome to produce novel Rep splice variants. Splicing generates Rep isoforms lacking the central oligomerization domain that cannot initiate replication but strongly repress the Rep promoter. Conversely, Rep mutants deficient in splicing promote replication but fail to repress transcription. Reduced Rep splicing interferes with the viral gene expression hierarchy and decreases infectivity. Our findings therefore reveal a previously unrecognized viral strategy in which alternative splicing produces functionally specialized viral protein isoforms, providing a mechanistic explanation for the dual role of Rep in viral replication and gene regulation. Splicing events with potentially similar functional consequences in related viruses suggest that this strategy may have convergently evolved across diverse viral lineages infecting different domains of life.

plant biology↗

Pervasive splicing in a plant DNA virus

RNA splicing is considered an oddity in plant viruses; here, unexpectedly, we find it to be prevalent in the geminivirus tomato yellow leaf curl virus. Transcriptome analysis revealed eight splicing events generating novel protein isoforms, six of which were validated and two shown to depend on the plant spliceosome. Splicing impairment reduced viral accumulation and symptom severity, demonstrating that splicing contributes to infectivity, potentially by expanding the viral proteome, and suggesting that plant virus transcriptomes need to be reassessed.

plant biology↗