Project description:Single-stranded DNA (ssDNA) binding proteins protect regions of ssDNA formed during processes such as DNA replication and repair. We here devise a genetic screen and identify the mitochondrial ssDNA-binding protein (mtSSB) as a key regulator of mtDNA levels. In mitochondria, RNA synthesis from the light-strand promoter (LSP) is required for transcription as well as for generating the primers for initiation of mtDNA synthesis. We find that mtSSB is essential for mtDNA replication initiation, as transcription is strongly upregulated from the LSP in an mtSSB knockout mouse model, but cannot support the switch to replication. Using deep sequencing as well as biochemical reconstitution experiments, we find that mtSSB is also necessary to restrict transcription initiation and primer formation to specific promoters and origins of replication both in vitro and in vivo. Pathological mutations in human mtSSB cannot efficiently support primer maturation and origin specific initiation of mtDNA replication in vitro.
Project description:Microbiome PCR primer model is a Named Entity Recognition (NER) model that identifies and annotates microbiome target gene primers in texts. This is the final model version used to annotate metagenomics publications in Europe PMC and enrich metagenomics studies in MGnify with primer metadata from literature. For more information, please refer to the following blogs: http://blog.europepmc.org/2020/11/europe-pmc-publications-metagenomics-annotations.html https://www.ebi.ac.uk/about/news/service-news/enriched-metadata-fields-mgnify-based-text-mining-associated-publications
Project description:RNA interference (RNAi) functions as the major host antiviral defense in insects, while less is understood about how to utilize antiviral RNAi in controlling viral infection in insects. Enoxacin belongs to the family of synthetic antibacterial compounds based on a fluoroquinolone skeleton that has been previously found to enhance RNAi in mammalian cells. In this study, we showed that enoxacin efficiently inhibited viral replication of Drosophila C virus (DCV) and Cricket paralysis virus (CrPV) in cultured Drosophila cells. Enoxacin promoted the loading of Dicer-2-processed virus-derived siRNA into the RNA-induced silencing complex, thereby enhancing antiviral RNAi response in infected cells. Moreover, enoxacin treatment elicited an RNAi-dependent in vivo protective efficacy against DCV or CrPV challenge in adult fruit flies. In addition, enoxacin also inhibited replication of flaviviruses, including Dengue virus and Zika virus, in Aedes mosquito cells in an RNAi-dependent manner. Together, our findings demonstrated that enoxacin can enhance RNAi in insects, and enhancing RNAi by enoxacin is an effective antiviral strategy against diverse viruses in insects, which may be exploited as a broad-spectrum antiviral agent to control vector transmission of arboviruses or viral diseases in insect farming.