Poster abstracts

Poster number 103 submitted by Christina Ross

Probing the role of m6A RNA modification in the HIV-1 genomic RNA 5'UTR

Christina Ross (Department of Chemistry and Biochemistry and Center for Retroviral Research, The Ohio State University, Columbus, OH 43210), Karin Musier-Forsyth (Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, Columbus OH 43210)

Abstract:
RNA modifications affect all aspects of RNA biology, likely impacting processes in viral replication such as RNA localization, stability, and assembly. To assemble virions, HIV-1 must select full-length genomic RNA (gRNA) from the cytoplasmic pool of cellular and viral RNA. Packaging is orchestrated by viral polyprotein Gag, which specifically interacts with the HIV-1 5'UTR RNA structure. Specific interactions between Gag and gRNA occur at sites in the packaging signal element (Psi) within the 5'UTR. Two N-6-methyladenosine (m6A) modifications have been previously identified in the 5'UTR, including one within Psi at an identified Gag binding site, and one in the tRNA primer binding site. We hypothesize m6A modifications in the HIV-1 5'UTR influence viral replication and assembly through shifting RNA structure and impacting tRNA and Gag interactions. We used splint ligation to construct Psi RNA, with the initial goal of producing specifically methylated Psi for binding studies. Salt-titration fluorescence anisotropy assays will be used to parse differences in specific and electrostatic Psi RNA-Gag interactions. In addition to binding, we aim to probe RNA structural differences between unmethylated and methylated RNA using native gel electrophoresis and RNA structure-probing. These studies may shed light on potential effects m6A has on retroviral packaging with implications for the development of therapeutics targeting this step in the HIV-1 lifecycle.

Keywords: HIV-1, m6A , RNA