Poster abstracts

Poster number 20 submitted by Sarah Golconda

Function of site-specific N6-methyladenosine (m6A) modifications of HIV-1 RNA in virus-host interactions

Sarah Golconda (Dept. of Veterinary Bioscience), Ga-Eun Lee, Alice Baek, Sanggu Kim (Dept. of Veterinary Bioscience, College of Veterinary Medicine, The Ohio State University)

Abstract:
Decoding the dynamics between HIV-1 RNA and its host interactions is crucial to unraveling the pathways essential to HIV-1 survival, potentially leading to the discovery of novel drug targets for controlling the late stages of viral replication. However, the structure complexity, chemical modifications, and stability of HIV-1 RNA limit in-depth studies of its multifaceted roles in viral replication. Recently, we have demonstrated nucleotide-resolution mapping of chemical modifications on full-length HIV-1 RNAs using innovative Nanopore direct RNA sequencing and tandem mass-spectrometry. Our data unveiled a surprisingly simple modification landscape on HIV-1 RNAs, revealing only three predominant modification peaks near the 3' end. Each of these modification peaks indicates site-specific, high-stoichiometry N6-methyladenosine (m6A) modifications that are crucial for maintaining normal levels of HIV-1 RNA splicing and translation. Additionally, we discovered these m6As possess unique functional properties and deposition patterns on HIV-1 RNAs, distinct from those typically observed in cellular transcripts, suggesting HIV-1-specific and context-dependent roles for these m6As. Given the crucial role of host machineries in viral RNA expression and post-transcriptional modifications, we explored whether knocking out the site-specific m6As on HIV-1 RNA affects host gene expression in virus-producing cells. Interestingly, cells producing m6A-knockout (mutant) HIV-1 RNAs exhibit gene expression profiles distinct from those of WT virus-producing cells. Gene profiling revealed that the transcripts differentially expressed between these cells are potentially important for viral RNA production and replication. These key findings provide insights into the molecular mechanisms of m6A-mediated virus-host interactions and an uncharacterized evolutionary strategy of HIV-1 utilizing its site-specific m6As.

Keywords: HIV-1 RNA, m6A, Virus-Host Interactions