Role of aminoacyl-tRNA synthetases and viral RNA structure in the initiation of reverse transcription
Year: 2016
Type: article
Abstract: Human T-cell leukemia virus type-1 (HTLV-1) is a human retrovirus that causes adult T-cell leukemia/lymphoma (ATL)—a rapidly degenerative non-Hodgkin’s lymphoma that affects roughly 5% of infected individuals. According to the most recent estimates, 5-10 million people are infected with HTLV-1 worldwide, yet there are currently no successful therapies for ATL. This underlines the importance of further research into the retroviral lifecycle. Before the genome of a retrovirus can be integrated into the host cell genome, it must undergo reverse transcription (RT) from RNA to DNA. In order for RT to initiate, a tRNA primer must anneal to the primer binding site (PBS) in the 5’ untranslated region (5’UTR) of the retroviral genome. Our lab has demonstrated that human lysyl-tRNA synthetase (hLysRS) facilitates this process in HIV-1 by binding a tRNA-like-element (TLE) near the PBS, localizing the tRNALys3 primer. The primer for HTLV-1 RT is tRNAPro; therefore, we hypothesize that this virus could employ a similar mechanism involving human prolyl-tRNA synthetase (hProRS) binding to a TLE. The secondary structure of the HTLV-1 5’UTR was solved using Selective 2’ Hydroxyl Acylation analyzed by Primer Extension (SHAPE), revealing a possible TLE stem loop that resembles the anticodon of tRNAPro and displays high sequence conservation across known isolates. Equilibrium binding studies and RNA probing techniques are being used to characterize the interaction between hProRS and the HTLV-1 5’UTR. Fluorescence anisotropy competition assays have shown that the HTLV-1 5’UTR is capable of competing tRNAPro off of hProRS. Preliminary RNase and SHAPE probing experiments have been performed, and experiments to probe the HTLV-1-hProRS and the HIV-1-hLysRS complexes are in progress. These experiments will allow us to characterize and compare the involvement of aminoacyl-tRNA synthetases in the initiation of RT, and provide insight into an important retroviral mechanism and potential drug target.
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2482531491