Poster abstracts
Poster number 140 submitted by Zixi Long
Role of YBX1 in the HTLV-1 Lifecycle
Zixi Long (Molecular, Cellular and Developmental Biology Program,Ohio State University, Columbus, OH), Yu-Ci Syu (Molecular, Cellular and Developmental Biology Program,Ohio State University, Columbus, OH), Amanda Panfil (Department of Veterinary Biosciences, Ohio State University, Columbus, OH), Karin Musier-Forsyth (Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH)
Abstract:
Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus that causes adult T-cell leukemia/lymphoma (ATLL) in ~5% of infected individuals. Unlike HIV-1, there are no clinically approved effective antiretroviral therapies for HTLV-1. In the late stage of its lifecycle, the viral Gag protein packages viral genomic RNA into immature particles at the plasma membrane before budding. The role of host proteins in this step is not well defined. Affinity tagging/purification-mass spectrometry (AP-MS) was used to identify HTLV-1 Gag-interacting partners. Twin-strep–tagged Gag expressed in HEK293T cells was pulled down with streptavidin, and co-purified proteins were analyzed by MS. Among the top hits was Y-box-binding protein 1 (YBX1), a ubiquitous transcription factor with numerous nucleic acid and protein partners. YBX1 promotes cell proliferation by stabilizing oncogene transcripts and has been shown to bind HTLV-1 Tax, enhancing viral transcription. Co-immunoprecipitation confirmed YBX1–Gag binding in an RNA-independent manner. Mapping studies showed this interaction is mediated by Gag nucleocapsid zinc fingers and YBX1 C-terminal domain 2. Virion analysis revealed YBX1 is packaged into HTLV-1 particles. Ongoing studies are assessing how YBX1 knockout affects viral infectivity and RNA packaging, supporting its potential as a therapeutic target in HTLV-1 infection.
Keywords: HTLV-1, Gag, YBX1