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HIV RNA splicing

Ann Baeyens, Evelien Naessens, Anouk Van Nuffel, Karin E Weening, Anne-Marie Reilly, Eva Claeys, Wim Trypsteen, Linos Vandekerckhove, Sven Eyckerman, Kris Gevaert, Bruno Verhasselt
To facilitate studies on Vpr function in replicating HIV-1, we aimed to tag the protein in an infectious virus. First we showed that N-, but not C-terminal HA/FLAG tagging of Vpr protein preserves Vpr cytopathicity. Cloning the tags into proviral DNA however ablated viral production and replication. By construction of additional viral variants we could show this defect was not protein- but RNA-dependent and sequence specific, and characterized by oversplicing of the genomic RNA. Simulation of genomic RNA folding suggested that introduction of the tag sequence induced an alternative folding structure in a region enriched in splice sites and splicing regulatory sequences...
October 10, 2016: Scientific Reports
Philip C Bevilacqua, Laura E Ritchey, Zhao Su, Sarah M Assmann
Single-stranded RNA molecules fold into extraordinarily complicated secondary and tertiary structures as a result of intramolecular base pairing. In vivo, these RNA structures are not static. Instead, they are remodeled in response to changes in the prevailing physicochemical environment of the cell and as a result of intramolecular base pairing and interactions with RNA-binding proteins. Remarkable technical advances now allow us to probe RNA secondary structure at single-nucleotide resolution and genome wide, both in vitro and in vivo...
September 14, 2016: Annual Review of Genetics
Gianluigi Lichinchi, Shang Gao, Yogesh Saletore, Gwendolyn Michelle Gonzalez, Vikas Bansal, Yinsheng Wang, Christopher E Mason, Tariq M Rana
N(6)-methyladenosine (m(6)A) is the most prevalent internal modification of eukaryotic mRNA. Very little is known of the function of m(6)A in the immune system or its role in host-pathogen interactions. Here, we investigate the topology, dynamics and bidirectional influences of the viral-host RNA methylomes during HIV-1 infection of human CD4 T cells. We show that viral infection triggers a massive increase in m(6)A in both host and viral mRNAs. In HIV-1 mRNA, we identified 14 methylation peaks in coding and noncoding regions, splicing junctions and splicing regulatory sequences...
2016: Nature Microbiology
Jiang Gu, Qihan Chen, Xiao Xiao, Fumiaki Ito, Aaron Wolfe, Xiaojiang S Chen
APOBEC3H (A3H) is the most polymorphic member in the APOBEC3 family. Seven haplotypes (hap I-VII) and four mRNA splicing variants (SV) of A3H have been identified. The various haplotypes differ in anti-HIV activity, which is attributed to differences in protein stability, sub-cellular distribution, and/or RNA binding and virion packaging. Here we report the first comparative biochemical studies of all the A3H variants using highly purified proteins. We show that all haplotypes were stably expressed and could be purified to homogeneity by E...
August 14, 2016: Journal of Molecular Biology
Nancy Mueller, Atze T Das, Ben Berkhout
RNA splicing is a critical step in the human immunodeficiency virus type 1 (HIV-1) replication cycle because it controls the expression of the complex viral proteome. The major 5' splice site (5'ss) that is positioned in the untranslated leader of the HIV-1 RNA transcript is of particular interest because it is used for the production of the more than 40 differentially spliced subgenomic mRNAs. HIV-1 splicing needs to be balanced tightly to ensure the proper levels of all viral proteins, including the Gag-Pol proteins that are translated from the unspliced RNA...
2016: Viruses
Hiromi Imamichi, Robin L Dewar, Joseph W Adelsberger, Catherine A Rehm, Una O'Doherty, Ellen E Paxinos, Anthony S Fauci, H Clifford Lane
Despite years of plasma HIV-RNA levels <40 copies per milliliter during combination antiretroviral therapy (cART), the majority of HIV-infected patients exhibit persistent seropositivity to HIV-1 and evidence of immune activation. These patients also show persistence of proviruses of HIV-1 in circulating peripheral blood mononuclear cells. Many of these proviruses have been characterized as defective and thus thought to contribute little to HIV-1 pathogenesis. By combining 5'LTR-to-3'LTR single-genome amplification and direct amplicon sequencing, we have identified the presence of "defective" proviruses capable of transcribing novel unspliced HIV-RNA (usHIV-RNA) species in patients at all stages of HIV-1 infection...
August 2, 2016: Proceedings of the National Academy of Sciences of the United States of America
Yolanda Vega, Elena Delgado, Jorge de la Barrera, Cristina Carrera, Ángel Zaballos, Isabel Cuesta, Ana Mariño, Antonio Ocampo, Celia Miralles, Sonia Pérez-Castro, Hortensia Álvarez, Isabel López-Miragaya, Elena García-Bodas, Francisco Díez-Fuertes, Michael M Thomson
HIV-1 RNAs are generated through a complex splicing mechanism, resulting in a great diversity of transcripts, which are classified in three major categories: unspliced, singly spliced (SS), and doubly spliced (DS). Knowledge on HIV-1 RNA splicing in vivo and by non-subtype B viruses is scarce. Here we analyze HIV-1 RNA splice site usage in CD4+CD25+ lymphocytes from HIV-1-infected individuals through pyrosequencing. HIV-1 DS and SS RNAs were amplified by RT-PCR in 19 and 12 samples, respectively. 13,108 sequences from HIV-1 spliced RNAs, derived from viruses of five subtypes (A, B, C, F, G), were identified...
2016: PloS One
Ilker Kudret Sariyer, Rahsan Sariyer, Jessica Otte, Jennifer Gordon
OBJECTIVE: PML is a rare and fatal demyelinating disease of the CNS caused by the human polyomavirus, JC virus (JCV), which occurs in AIDS patients and those on immunosuppressive monoclonal antibody therapies (mAbs). We sought to identify mechanisms that could stimulate reactivation of JCV in a cell culture model system and targeted pathways which could affect early gene transcription and JCV T-antigen production, which are key steps of the viral life cycle for blocking reactivation of JCV...
2016: PloS One
Fengchun Ye, Jonathan Karn
Post-transcriptional m(6)A methylation of RNA has profound effects on RNA splicing, export, stability, and translation. A recent study by Lichinchi et al. (2016) and one in this issue of Cell Host & Microbe by Kennedy et al. (2016) demonstrate that HIV mRNA is extensively m(6)A methylated, which promotes efficient virus replication.
May 11, 2016: Cell Host & Microbe
Patrick E Jackson, Denis M Tebit, David Rekosh, Marie-Louise Hammarskjold
The HIV-1 replication cycle requires the nucleocytoplasmic export of intron-containing viral RNAs, a process that is ordinarily restricted. HIV overcomes this by means of the viral Rev protein, which binds to an RNA secondary structure called the Rev response element (RRE) present in all unspliced or incompletely spliced viral RNA transcripts. The resulting mRNP complex is exported through interaction with cellular factors. The Rev-RRE binding interaction is increasingly understood to display remarkable structural plasticity, but little is known about how Rev-RRE sequence differences affect functional activity...
September 2016: AIDS Research and Human Retroviruses
Xinxia Peng, Shuying S Li, Peter B Gilbert, Daniel E Geraghty, Michael G Katze
The phase III Thai RV144 vaccine trial showed an estimated vaccine efficacy (VE) to prevent HIV-1 infection of 31.2%, which has motivated the search for immune correlates of vaccine protection. In a recent report, several single nucleotide polymorphisms (SNPs) in FCGR2C were identified to associate with the level of VE in the RV144 trial. To investigate the functional significance of these SNPs, we utilized a large scale B cell RNA sequencing database of 462 individuals from the 1000 Genomes Project to examine associations between FCGR2C SNPs and gene expression...
2016: PloS One
Mariluz Araínga, Hang Su, Larisa Y Poluektova, Santhi Gorantla, Howard E Gendelman
Humanized mice have emerged as a testing platform for HIV-1 pathobiology by reflecting natural human disease processes. Their use to study HIV-1 biology, virology, immunology, pathogenesis and therapeutic development has served as a robust alternative to more-well developed animal models for HIV/AIDS. A critical component in reflecting such human pathobiology rests in defining the tissue and cellular sites for HIV-1 infection. To this end, we examined the tissue sites for viral infection in bone marrow, blood, spleens, liver, gut, brain, kidney and lungs of human CD34+ hematopoietic stem cell engrafted virus-infected NOD...
2016: Scientific Reports
Maja Kiselinova, Ward De Spiegelaere, Maria Jose Buzon, Eva Malatinkova, Mathias Lichterfeld, Linos Vandekerckhove
The persistence of a reservoir of latently infected CD4 T cells remains one of the major obstacles to cure HIV. Numerous strategies are being explored to eliminate this reservoir. To translate these efforts into clinical trials, there is a strong need for validated biomarkers that can monitor the reservoir over time in vivo. A comprehensive study was designed to evaluate and compare potential HIV-1 reservoir biomarkers. A cohort of 25 patients, treated with suppressive antiretroviral therapy was sampled at three time points, with median of 2...
March 2016: PLoS Pathogens
Jason D Fernandes, David S Booth, Alan D Frankel
HIV replication requires the nuclear export of essential, intron-containing viral RNAs. To facilitate export, HIV encodes the viral accessory protein Rev which binds unspliced and partially spliced viral RNAs and creates a ribonucleoprotein complex that recruits the cellular Chromosome maintenance factor 1 export machinery. Exporting RNAs in this manner bypasses the necessity for complete splicing as a prerequisite for mRNA export, and allows intron-containing RNAs to reach the cytoplasm intact for translation and virus packaging...
July 2016: Wiley Interdisciplinary Reviews. RNA
Zhong-Min Ma, Joseph Dutra, Linda Fritts, Christopher J Miller
UNLABELLED: The human immunodeficiency virus (HIV) is primarily transmitted by heterosexual contact, and approximately equal numbers of men and women worldwide are infected with the virus. Understanding the biology of HIV acquisition and dissemination in men exposed to the virus by insertive penile intercourse is likely to help with the rational design of vaccines that can limit or prevent HIV transmission. To characterize the target cells and dissemination pathways involved in establishing systemic simian immunodeficiency virus (SIV) infection, we necropsied male rhesus macaques at 1, 3, 7, and 14 days after penile SIV inoculation and quantified the levels of unspliced SIV RNA and spliced SIV RNA in tissue lysates and the number of SIV RNA-positive cells in tissue sections...
April 2016: Journal of Virology
Niyati Jain, Christopher E Morgan, Brittany D Rife, Marco Salemi, Blanton S Tolbert
Splicing patterns in human immunodeficiency virus type 1 (HIV-1) are maintained through cis regulatory elements that recruit antagonistic host RNA-binding proteins. The activity of the 3' acceptor site A7 is tightly regulated through a complex network of an intronic splicing silencer (ISS), a bipartite exonic splicing silencer (ESS3a/b), and an exonic splicing enhancer (ESE3). Because HIV-1 splicing depends on protein-RNA interactions, it is important to know the tertiary structures surrounding the splice sites...
January 29, 2016: Journal of Biological Chemistry
Parmit Kumar Singh, Matthew R Plumb, Andrea L Ferris, James R Iben, Xiaolin Wu, Hind J Fadel, Brian T Luke, Caroline Esnault, Eric M Poeschla, Stephen H Hughes, Mamuka Kvaratskhelia, Henry L Levin
The host chromatin-binding factor LEDGF/p75 interacts with HIV-1 integrase and directs integration to active transcription units. To understand how LEDGF/p75 recognizes transcription units, we sequenced 1 million HIV-1 integration sites isolated from cultured HEK293T cells. Analysis of integration sites showed that cancer genes were preferentially targeted, raising concerns about using lentivirus vectors for gene therapy. Additional analysis led to the discovery that introns and alternative splicing contributed significantly to integration site selection...
November 1, 2015: Genes & Development
Ferdous Kadri, Marco Pacifici, Anna Wilk, Amanda Parker-Struckhoff, Luis Del Valle, Kurt F Hauser, Pamela E Knapp, Christopher Parsons, Duane Jeansonne, Adam Lassak, Francesca Peruzzi
The HIV-1 transactivator protein Tat is implicated in the neuronal damage that contributes to neurocognitive impairment affecting people living with HIV/AIDS. Aberrant splicing of TAU exon 10 results in tauopathies characterized by alterations in the proportion of TAU isoforms containing three (3R) or four (4R) microtubule-binding repeats. The splicing factor SC35/SRSF2 binds to nuclear RNA and facilitates the incorporation of exon 10 in the TAU molecule. Here, we utilized clinical samples, an animal model, and neuronal cell cultures and found that Tat promotes TAU 3R up-regulation through increased levels of phosphorylated SC35, which is retained in nuclear speckles...
December 25, 2015: Journal of Biological Chemistry
Katarzyna J Purzycka, Guy R Pilkington, Barbara K Felber, Stuart F J Le Grice
Replication of retroviruses and transposition of endogenous retroelements exploits a unique mechanism of post-transcriptional regulation as a means of exporting their incompletely-spliced mRNAs (which serve as both the genomic RNA and the template for protein synthesis). Following discovery of the Rev response element (RRE) that mediates nucleocytoplasmic export of the full-length and singly-spliced human immunodeficiency virus type 1 (HIV-1) genome, equivalent cis-acting regulatory elements have been characterized for both complex and simple retroviruses and retroelements, together with the obligate viral and host proteins with which they interact...
March 2015: Mobile Genetic Elements
Francesco Andrea Procopio, Rémi Fromentin, Deanna A Kulpa, Jessica H Brehm, Anne-Gaelle Bebin, Matthew C Strain, Douglas D Richman, Una O'Doherty, Sarah Palmer, Frederick M Hecht, Rebecca Hoh, Richard J O Barnard, Michael D Miller, Daria J Hazuda, Steven G Deeks, Rafick-Pierre Sékaly, Nicolas Chomont
BACKGROUND: Quantifying latently infected cells is critical to evaluate the efficacy of therapeutic strategies aimed at reducing the size of the long-lived viral reservoir, but the low frequency of these cells makes this very challenging. METHODS: We developed TILDA (Tat/rev Induced Limiting Dilution Assay) to measure the frequency of cells with inducible multiply-spliced HIV RNA, as these transcripts are usually absent in latently infected cells but induced upon viral reactivation...
August 2015: EBioMedicine
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