Poster abstracts

Poster number 8 submitted by Jacob Horn

A thorough investigation of SARS-CoV-2 5’ UTR elements that regulate viral translation.

Jacob S. Horn (Cellular and Molecular Biology Program, University of Michigan), Rachel O. Niederer (Department of Biological Chemistry, University of Michigan )

Abstract:
SARS-CoV-2 protein Nsp1 induces a global translation shutdown in host cells upon infection. The viral genome can escape the translational shutdown via secondary structure in its 5’ untranslated region (UTR). The first hairpin structure, stem-loop 1 (SL1), has been identified as necessary and sufficient to evade Nsp1-mediated translation shutdown. Despite proven functional roles within the 5’ UTR, other elements remain understudied. To identify other potentially functional regions within the viral 5’ UTR that might influence translation we used a recently developed method called direct analysis of ribosome targeting (DART), a high throughput method that tests the ribosome recruitment ability of thousands of 5’ UTRs. We generated a diverse pool of sequences that will allow thorough examination of each region of the 5’ UTR and its role in translation and evasion of host shutdown. The pool includes natural mutations from the NCBI virus sequence repository and artificial perturbations to known secondary structure and sequence. This work is novel because analysis of mutations in SARS-CoV-2 is usually restricted to viral proteins, while the mutations to the untranslated regions are left understudied. Our preliminary DART experiment revealed that natural mutations can facilitate up to 10-fold differences in ribosome recruitment scores. For example, some Omicron and Delta variants yielded >8 fold increases in ribosome recruitment compared to the original isolate of the virus. Together, these data will allow us to comprehensively identify translational control elements within the SARS-CoV-2 5’ UTR to find potential therapeutic targets.

Keywords: 5 UTR, SARS-CoV-2, translation