A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a recount of this collective knowledge starting with the genomic elements (DNA and nascent TAR RNA stem-loop) and transcription factors (cellular and the viral transactivator Tat), and later transitioning to the assembly and regulation of transcription initiation and elongation complexes, and the role of chromatin structure. Compelling evidence support a core HIV-1 transcriptional program regulated by the sequential and concerted action of cellular transcription factors and Tat to promote initiation and sustain elongation, highlighting the efficiency of a small virus to take over its host to produce the high levels of transcription required for viral replication. I summarize new advances including the use of CRISPR-Cas9, genetic tools for acute factor depletion, and imaging to study transcriptional dynamics, bursting and the progression through the multiple phases of the transcriptional cycle. Finally, I describe current challenges to future major advances and discuss areas that deserve more attention to both bolster our basic knowledge of the core HIV-1 transcriptional program and open up new therapeutic opportunities.
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http://dx.doi.org/10.1016/j.jmb.2024.168690 | DOI Listing |
Viruses
January 2025
Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
Retroviral genome selection and virion assembly remain promising targets for novel therapeutic intervention. Recent studies have demonstrated that the Gag proteins of Rous sarcoma virus (RSV) and human immunodeficiency virus type-1 (HIV-1) undergo nuclear trafficking, colocalize with nascent genomic viral RNA (gRNA) at transcription sites, may interact with host transcription factors, and display biophysical properties characteristic of biomolecular condensates. In the present work, we utilized a controlled in vitro condensate assay and advanced imaging approaches to investigate the effects of interactions between RSV Gag condensates and viral and nonviral RNAs on condensate abundance and organization.
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December 2024
Laboratory of Molecular and Cellular Virology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile.
RNA-binding proteins (RBPs) are cellular factors involved in every step of RNA metabolism. During HIV-1 infection, these proteins are key players in the fine-tuning of viral and host cellular and molecular pathways, including (but not limited to) viral entry, transcription, splicing, RNA modification, translation, decay, assembly, and packaging, as well as the modulation of the antiviral response. Targeted studies have been of paramount importance in identifying and understanding the role of RNA-binding proteins that bind to HIV-1 RNAs.
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January 2025
Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA.
As of 2023, there were 39.9 million people living with Human Immunodeficiency Virus type 1 (HIV-1). Although great strides have been made in treatment options for HIV-1, and our understanding of the HIV-1 life cycle has vastly improved since the start of this global health crisis, a functional cure remains elusive.
View Article and Find Full Text PDFIntroduction: Tat protein is a trans-activator of HIV-1 genome transcription, with additional functions including the ability to induce the chronic inflammatory process. Natural amino acid polymorphisms in Tat may affect its functional properties and the course of HIV infection. The aim of this work is to analyze the marks of Tat consensus sequences in non-A6 HIV-1 variants characteristic of the Russian Federation, as well as study natural polymorphisms in Tat CRF63_02A6 and subtype B variants circulating in Russia.
View Article and Find Full Text PDFSci Signal
January 2025
Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310000, China.
Activation of the stimulator of interferon genes (STING) pathway by cytosolic DNA leads to the activation of the transcription factors interferon regulatory factor 3 (IRF3) and nuclear factor κB (NF-κB). Although many viruses produce proteins that inhibit IRF3-dependent antiviral responses, some viruses produce proteins that inhibit STING-induced NF-κB activation without blocking IRF3 activation. Here, we found that STING-activated, NF-κB-dependent, and IRF3-independent innate immunity inhibited the replication of the DNA virus herpes simplex virus type 1 (HSV-1), the RNA virus coxsackievirus A16 (CV-A16), and the retrovirus HIV-1.
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