Poster abstracts
Poster number 145 submitted by Andrea Ascura
SPENding host factors: Cedar virus recruits SPEN family proteins to regulate viral infection and redecorate m6A modifications
Andrea Ascura (Department of Biochemistry, Vanderbilt University), Stephen Clarke (Department of Biochemistry, Vanderbilt University), Manuel Ascano (Department of Biochemistry, Vanderbilt University)
Abstract:
Henipavirus is an emerging group of highly lethal, bat-borne RNA viruses with pandemic potential. The prototypical members, Hendra and Nipah virus, are BSL-4 pathogens that elicit severe respiratory and neurological diseases with case fatality rates of up to 90%. There are currently no approved antiviral therapeutics to treat infection in humans. Despite their rapid global emergence and expanding threat to public health, henipaviruses are largely uncharacterized pathogens due to their strict biocontainment requirements and lack of tractable models. Therefore, a molecular understanding of henipavirus pathobiology remains elusive. Cedar virus (CedV) (Marsh et al., 2012), a recently discovered non-pathogenic henipavirus, represents an opportunity to not only understand henipavirus infection but may also reveal shared mechanisms among other BSL-4 viruses. Using VIRal CrossLinking And Solid-phase Purification (VIR-CLASP) (Kim et al., 2020), we uncovered the first henipavirus RNA interactome consisting of ~200 human proteins that directly bind to the pre-replicated CedV RNA genome. We found an unexpected enrichment of host replication and transcriptional regulators suggesting novel nucleic acid metabolic processes exploited by CedV. We show that a subset of these CedV interactors, particularly SPEN family proteins, which are canonical RNA binding partners for Xist lncRNA (Chu et al., 2015), are required for viral infection. Using nanopore direct RNA sequencing, we reveal that these SPEN family proteins redecorate m6A modifications on viral mRNA and that dysregulation of m6A modulates viral mRNA transcription. Our findings uncover critical host factors co-opted by pre-replicated henipavirus RNA and reveal an uncharacterized role of SPEN family proteins in not only promoting viral infection, but also nucleating m6A machinery.
References:
Chu, C., Zhang, Qiangfeng C., da Rocha, Simão T., Flynn, Ryan A., Bharadwaj, M., Calabrese, J. M.,…Chang, Howard Y. (2015/04/09). Systematic Discovery of Xist RNA Binding Proteins. Cell, 161(2). https://doi.org/10.1016/j.cell.2015.03.025
Kim, B., Arcos, S., Rothamel, K., Jian, J., Rose, K. L., Mcdonald, W. H.,…Ascano, M. (2020). Discovery of Widespread Host Protein Interactions with the Pre-replicated Genome of CHIKV Using VIR-CLASP. Molecular Cell, 78(4), 624-640.e627. https://doi.org/10.1016/j.molcel.2020.04.013
Marsh, G. A., De Jong, C., Barr, J. A., Tachedjian, M., Smith, C., Middleton, D.,…Wang, L.-F. (2012). Cedar Virus: A Novel Henipavirus Isolated from Australian Bats. PLoS Pathogens, 8(8), e1002836. https://doi.org/10.1371/journal.ppat.1002836
Keywords: RNA binding proteins, RNA virus, host-pathogen interactions