The biased adenosine-rich content of the HIV-1 genome serves as a molecular signature that facilitates efficient packaging
Abstract
The HIV-1 genome [genomic RNA (gRNA)] has an unusually biased nucleotide content and is rich in adenosines. Selective packaging of the gRNA is thought to be driven by specific binding of the nucleocapsid (NC) domain of the viral Gag protein to the packaging signal (Ψ) in the host cell cytosol. However, deletion of regions within Ψ reduces—but does not completely abolish—genome packaging. To probe whether another feature of the gRNA may contribute to the selective gRNA packaging process, we replaced NC with heterologous RNA-binding domains (RBDs) with distinct RNA-binding properties. Surprisingly, despite disparate RNA binding specificities, all Gag-RBD chimeras successfully recruited the gRNA to the plasma membrane, suggesting that the initial gRNA recognition in the cytosol is not rate limiting. Notwithstanding, many chimeras exhibiting G/C binding specificity were arrested at the assembly stage. Only the Gag-SRSF5 chimera, which multimerized efficiently on adenosine-rich sequences on the gRNA, assembled efficiently and packaged gRNA at near wild-type levels. Importantly, rationally designed mutations that altered the A/G-rich binding specificity of Gag-SRSF5 decreased genome encapsidation efficiency. Furthermore, many Gag chimeras displayed potent dominant negative activities, highlighting NC functions as a targetable step in virus replication. Together, our findings reveal an unexpected aspect of the HIV-1 gRNA, its biased nucleotide content, as a key driver of selective genome packaging.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (20)
Hung R. Vuong
Department of Molecular Microbiology, Washington University School of Medicine
Qianzi Zhou
Department of Molecular Microbiology, Washington University School of Medicine
Sydney L. Lesko
McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison
Kasyap Tenneti
Department of Molecular Microbiology, Washington University School of Medicine
Keanu Davis
Department of Molecular Microbiology, Washington University School of Medicine
Shanyqua Scott
McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison
Moming Guo
Department of Molecular Microbiology, Washington University School of Medicine
Daphne Boodwa-Ko
Department of Molecular Microbiology, Washington University School of Medicine
Jenna E. Eschbach
Department of Molecular Microbiology, Washington University School of Medicine
Kamya Gopal
Cell and Molecular Biology Program, University of Michigan Medical School
Jessica M. Porter
Department of Molecular Microbiology, Washington University School of Medicine
Qibo Wang
Department of Molecular Microbiology, Washington University School of Medicine
Ming Xia
Department of Otolaryngology, Shandong Provincial Hospital, Medical Science and Technology Innovation Center, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences
Anthony Boateng
Department of Molecular Microbiology, Washington University School of Medicine
Yiqing Wang
Department of Biomedical Engineering, College of Engineering and Applied Sciences
Shawn Mohammed
Department of Molecular Microbiology, Washington University School of Medicine
Nakyung Lee
Department of Molecular Microbiology, Washington University School of Medicine
Alice Telesnitsky
Department of Microbiology and Immunology, University of Michigan Medical School
Nathan M. Sherer
McArdle Laboratory for Cancer Research (Department of Oncology), University of Wisconsin-Madison
Sebla B. Kutluay
Department of Molecular Microbiology, Washington University School of Medicine