1
|
Atabekova AK, Lazareva EA, Lezzhov AA, Golyshev SA, Skulachev BI, Morozov SY, Solovyev AG. Defense Responses Induced by Viral Movement Protein and Its Nuclear Localization Modulate Virus Cell-to-Cell Transport. PLANTS (BASEL, SWITZERLAND) 2024; 13:2550. [PMID: 39339524 PMCID: PMC11435296 DOI: 10.3390/plants13182550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2024] [Revised: 09/04/2024] [Accepted: 09/07/2024] [Indexed: 09/30/2024]
Abstract
Movement proteins (MPs) encoded by plant viruses are essential for cell-to-cell transport of viral genomes through plasmodesmata. The genome of hibiscus green spot virus contains a module of two MP genes termed 'binary movement block' (BMB), encoding the proteins BMB1 and BMB2. Here, BMB1 is shown to induce a defense response in Nicotiana benthamiana plants that inhibits BMB-dependent virus transport. This response is characterized by the accumulation of reactive oxygen species, callose deposition in the cell wall, and upregulation of 9-LOX expression. However, the BMB1-induced response is inhibited by coexpression with BMB2. Furthermore, BMB1 is found to localize to subnuclear structures, in particular to Cajal bodies, in addition to the cytoplasm. As shown in experiments with a BMB1 mutant, the localization of BMB1 to nuclear substructures enhances BMB-dependent virus transport. Thus, the virus transport mediated by BMB proteins is modulated by (i) a BMB1-induced defense response that inhibits transport, (ii) suppression of the BMB1-induced response by BMB2, and (iii) the nuclear localization of BMB1 that promotes virus transport. Collectively, the data presented demonstrate multiple levels of interactions between viral pathogens and their plant hosts during virus cell-to-cell transport.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Andrey G. Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (A.K.A.); (E.A.L.); (A.A.L.); (S.A.G.); (B.I.S.); (S.Y.M.)
| |
Collapse
|
2
|
Behrens RT, Sherer NM. Retroviral hijacking of host transport pathways for genome nuclear export. mBio 2023; 14:e0007023. [PMID: 37909783 PMCID: PMC10746203 DOI: 10.1128/mbio.00070-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Recent advances in the study of virus-cell interactions have improved our understanding of how viruses that replicate their genomes in the nucleus (e.g., retroviruses, hepadnaviruses, herpesviruses, and a subset of RNA viruses) hijack cellular pathways to export these genomes to the cytoplasm where they access virion egress pathways. These findings shed light on novel aspects of viral life cycles relevant to the development of new antiviral strategies and can yield new tractable, virus-based tools for exposing additional secrets of the cell. The goal of this review is to summarize defined and emerging modes of virus-host interactions that drive the transit of viral genomes out of the nucleus across the nuclear envelope barrier, with an emphasis on retroviruses that are most extensively studied. In this context, we prioritize discussion of recent progress in understanding the trafficking and function of the human immunodeficiency virus type 1 Rev protein, exemplifying a relatively refined example of stepwise, cooperativity-driven viral subversion of multi-subunit host transport receptor complexes.
Collapse
Affiliation(s)
- Ryan T. Behrens
- Department of Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Nathan M. Sherer
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin, Madison, Wisconsin, USA
| |
Collapse
|
3
|
Yandrapally S, Sarkar S, Banerjee S. HIV-1 Tat commandeers nuclear export of Rev-viral RNA complex by controlling hnRNPA2-mediated splicing. J Virol 2023; 97:e0104423. [PMID: 37905837 PMCID: PMC10688328 DOI: 10.1128/jvi.01044-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/26/2023] [Indexed: 11/02/2023] Open
Abstract
IMPORTANCE HIV-infected host cells impose varied degrees of regulation on viral replication, from very high to abortive. Proliferation of HIV in astrocytes is limited when compared to immune cells, such as CD4+ T lymphocytes. Understanding such differential regulation is one of the key questions in the field as these cells permit HIV persistence and rebound viremia, challenging HIV treatment and clinical cure. This study focuses on understanding the molecular mechanism behind such cell-specific disparities. We show that one of the key mechanisms is the regulation of heterogenous nuclear ribonucleoprotein A2, a host factor involved in alternative splicing and RNA processing, by HIV-1 Tat in CD4+ T lymphocytes, not observed in astrocytes. This regulation causes an increase in the levels of unspliced/partially spliced viral RNA and nuclear export of Rev-RNA complexes which results in high viral propagation in CD4+ T lymphocytes. The study reveals a new mechanism imposed by HIV on host cells that determines the fate of infection.
Collapse
Affiliation(s)
- Sriram Yandrapally
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India
| | - Satarupa Sarkar
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India
| | - Sharmistha Banerjee
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India
| |
Collapse
|
4
|
Behrens RT, Rajashekar JK, Bruce JW, Evans EL, Hansen AM, Salazar-Quiroz N, Simons LM, Ahlquist P, Hultquist JF, Kumar P, Sherer NM. Exploiting a rodent cell block for intrinsic resistance to HIV-1 gene expression in human T cells. mBio 2023; 14:e0042023. [PMID: 37676006 PMCID: PMC10653828 DOI: 10.1128/mbio.00420-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/13/2023] [Indexed: 09/08/2023] Open
Abstract
IMPORTANCE Unlike humans, mice are unable to support HIV-1 infection. This is due, in part, to a constellation of defined minor, species-specific differences in conserved host proteins needed for viral gene expression. Here, we used precision CRISPR/Cas9 gene editing to engineer a "mousified" version of one such host protein, cyclin T1 (CCNT1), in human T cells. CCNT1 is essential for efficient HIV-1 transcription, making it an intriguing target for gene-based inactivation of virus replication. We show that isogenic cell lines engineered to encode CCNT1 bearing a single mouse-informed amino acid change (tyrosine in place of cysteine at position 261) exhibit potent, durable, and broad-spectrum resistance to HIV-1 and other pathogenic lentiviruses, and with no discernible impact on host cell biology. These results provide proof of concept for targeting CCNT1 in the context of one or more functional HIV-1 cure strategies.
Collapse
Affiliation(s)
- Ryan T. Behrens
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jyothi Krishnaswamy Rajashekar
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, Connecticut, USA
| | - James W. Bruce
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Edward L. Evans
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Amelia M. Hansen
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Natalia Salazar-Quiroz
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Lacy M. Simons
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Paul Ahlquist
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Judd F. Hultquist
- Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Priti Kumar
- Department of Internal Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Nathan M. Sherer
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| |
Collapse
|
5
|
Pillai VN, Ali LM, Prabhu SG, Krishnan A, Tariq S, Mustafa F, Rizvi TA. Expression, purification, and functional characterization of soluble recombinant full-length simian immunodeficiency virus (SIV) Pr55 Gag. Heliyon 2023; 9:e12892. [PMID: 36685375 PMCID: PMC9853374 DOI: 10.1016/j.heliyon.2023.e12892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/14/2022] [Accepted: 01/06/2023] [Indexed: 01/11/2023] Open
Abstract
The simian immunodeficiency virus (SIV) precursor polypeptide Pr55Gag drives viral assembly and facilitates specific recognition and packaging of the SIV genomic RNA (gRNA) into viral particles. While several studies have tried to elucidate the role of SIV Pr55Gag by expressing its different components independently, studies using full-length SIV Pr55Gag have not been conducted, primarily due to the unavailability of purified and biologically active full-length SIV Pr55Gag. We successfully expressed soluble, full-length SIV Pr55Gag with His6-tag in bacteria and purified it using affinity and gel filtration chromatography. In the process, we identified within Gag, a second in-frame start codon downstream of a putative Shine-Dalgarno-like sequence resulting in an additional truncated form of Gag. Synonymously mutating this sequence allowed expression of full-length Gag in its native form. The purified Gag assembled into virus-like particles (VLPs) in vitro in the presence of nucleic acids, revealing its biological functionality. In vivo experiments also confirmed formation of functional VLPs, and quantitative reverse transcriptase PCR demonstrated efficient packaging of SIV gRNA by these VLPs. The methodology we employed ensured the availability of >95% pure, biologically active, full-length SIV Pr55Gag which should facilitate future studies to understand protein structure and RNA-protein interactions involved during SIV gRNA packaging.
Collapse
Affiliation(s)
- Vineeta N. Pillai
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University, Al Ain, United Arab Emirates
| | - Lizna Mohamed Ali
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University, Al Ain, United Arab Emirates
| | - Suresha G. Prabhu
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University, Al Ain, United Arab Emirates
| | - Anjana Krishnan
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University, Al Ain, United Arab Emirates
| | - Saeed Tariq
- Department of Anatomy, College of Medicine and Health Sciences (CMHS), United Arab Emirates University, Al Ain, United Arab Emirates
| | - Farah Mustafa
- Department of Biochemistry, College of Medicine and Health Sciences (CMHS), United Arab Emirates University, Al Ain, United Arab Emirates,Zayed Center for Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates,Corresponding author. Department of Biochemistry, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), P.O. Box 15551, Al Ain, United Arab Emirates.
| | - Tahir A. Rizvi
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University, Al Ain, United Arab Emirates,Zayed Center for Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates,Corresponding author. Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), P.O. Box 15551, Al Ain, United Arab Emirates.
| |
Collapse
|
6
|
Spittler D, Indorato RL, Boeri Erba E, Delaforge E, Signor L, Harris SJ, Garcia-Saez I, Palencia A, Gabel F, Blackledge M, Noirclerc-Savoye M, Petosa C. Binding stoichiometry and structural model of the HIV-1 Rev/importin β complex. Life Sci Alliance 2022; 5:5/10/e202201431. [PMID: 35995566 PMCID: PMC9396022 DOI: 10.26508/lsa.202201431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/24/2022] Open
Abstract
HIV-1 Rev mediates the nuclear export of intron-containing viral RNA transcripts and is essential for viral replication. Rev is imported into the nucleus by the host protein importin β (Impβ), but how Rev associates with Impβ is poorly understood. Here, we report biochemical, mutational, and biophysical studies of the Impβ/Rev complex. We show that Impβ binds two Rev monomers through independent binding sites, in contrast to the 1:1 binding stoichiometry observed for most Impβ cargos. Peptide scanning data and charge-reversal mutations identify the N-terminal tip of Rev helix α2 within Rev's arginine-rich motif (ARM) as a primary Impβ-binding epitope. Cross-linking mass spectrometry and compensatory mutagenesis data combined with molecular docking simulations suggest a structural model in which one Rev monomer binds to the C-terminal half of Impβ with Rev helix α2 roughly parallel to the HEAT-repeat superhelical axis, whereas the other monomer binds to the N-terminal half. These findings shed light on the molecular basis of Rev recognition by Impβ and highlight an atypical binding behavior that distinguishes Rev from canonical cellular Impβ cargos.
Collapse
Affiliation(s)
- Didier Spittler
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Rose-Laure Indorato
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Elisabetta Boeri Erba
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Elise Delaforge
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Luca Signor
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Simon J Harris
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Isabel Garcia-Saez
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Andrés Palencia
- Institute for Advanced Biosciences, Structural Biology of Novel Targets in Human Diseases, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Grenoble, France
| | - Frank Gabel
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Martin Blackledge
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Marjolaine Noirclerc-Savoye
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| | - Carlo Petosa
- Université Grenoble Alpes, Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Structurale, Grenoble, France
| |
Collapse
|
7
|
Chiu YF, Huang YW, Chen CY, Chen YC, Gong YN, Kuo RL, Huang CG, Shih SR. Visualizing Influenza A Virus vRNA Replication. Front Microbiol 2022; 13:812711. [PMID: 35733972 PMCID: PMC9207383 DOI: 10.3389/fmicb.2022.812711] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Influenza A virus (IAV) has caused recurrent epidemics and severe pandemics. In this study, we adapted an MS2-MCP live-cell imaging system to visualize IAV replication. A reporter plasmid, pHH-PB2-vMSL, was constructed by replacing a part of the PB2-coding sequence in pHH-PB2 with a sequence encoding 24 copies of a stem-loop structure from bacteriophage MS2 (MSL). Binding of MS2 coat protein (MCP) fused to green fluorescent protein (GFP) to MSL enabled the detection of vRNA as fluorescent punctate signals in live-cell imaging. The introduction of pHH-PB2-vMSL into A549 cells transduced to express an MCP-GFP fusion protein lacking the nuclear localization signal (MCP-GFPdN), subsequently allowed tracking of the distribution and replication of PB2-vMSL vRNA after IAV PR8 infection. Spatial and temporal measurements revealed exponential increases in vRNA punctate signal intensity, which was only observed after membrane blebbing in apoptotic cells. Similar signal intensity increases in apoptotic cells were also observed after MDCK cells, transduced to express MCP-GFPdN, were infected with IAV carrying PB2-vMSL vRNA. Notably, PB2-vMSL vRNA replication was observed to occur only in apoptotic cells, at a consistent time after apoptosis initiation. There was a lack of observable PB2-vMSL vRNA replication in non-apoptotic cells, and vRNA replication was suppressed in the presence of apoptosis inhibitors. These findings point to an important role for apoptosis in IAV vRNA replication. The utility of the MS2-imaging system for visualizing time-sensitive processes such as viral replication in live host cells is also demonstrated in this study.
Collapse
Affiliation(s)
- Ya-Fang Chiu
- Department of Microbiology and Immunology, Chang Gung University, Taoyuan, Taiwan.,Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan.,Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yi-Wen Huang
- Department of Microbiology and Immunology, Chang Gung University, Taoyuan, Taiwan
| | - Chi-Yuan Chen
- Department of Microbiology and Immunology, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Chia Chen
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yu-Nong Gong
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan.,Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Rei-Lin Kuo
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan
| | - Chung-Guei Huang
- Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Shin-Ru Shih
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan
| |
Collapse
|
8
|
Evans EL, Pocock GM, Einsdorf G, Behrens RT, Dobson ETA, Wiedenmann M, Birkhold C, Ahlquist P, Eliceiri KW, Sherer NM. HIV RGB: Automated Single-Cell Analysis of HIV-1 Rev-Dependent RNA Nuclear Export and Translation Using Image Processing in KNIME. Viruses 2022; 14:903. [PMID: 35632645 PMCID: PMC9145009 DOI: 10.3390/v14050903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/21/2022] [Accepted: 04/23/2022] [Indexed: 01/27/2023] Open
Abstract
Single-cell imaging has emerged as a powerful means to study viral replication dynamics and identify sites of virus−host interactions. Multivariate aspects of viral replication cycles yield challenges inherent to handling large, complex imaging datasets. Herein, we describe the design and implementation of an automated, imaging-based strategy, “Human Immunodeficiency Virus Red-Green-Blue” (HIV RGB), for deriving comprehensive single-cell measurements of HIV-1 unspliced (US) RNA nuclear export, translation, and bulk changes to viral RNA and protein (HIV-1 Rev and Gag) subcellular distribution over time. Differentially tagged fluorescent viral RNA and protein species are recorded using multicolor long-term (>24 h) time-lapse video microscopy, followed by image processing using a new open-source computational imaging workflow dubbed “Nuclear Ring Segmentation Analysis and Tracking” (NR-SAT) based on ImageJ plugins that have been integrated into the Konstanz Information Miner (KNIME) analytics platform. We describe a typical HIV RGB experimental setup, detail the image acquisition and NR-SAT workflow accompanied by a step-by-step tutorial, and demonstrate a use case wherein we test the effects of perturbing subcellular localization of the Rev protein, which is essential for viral US RNA nuclear export, on the kinetics of HIV-1 late-stage gene regulation. Collectively, HIV RGB represents a powerful platform for single-cell studies of HIV-1 post-transcriptional RNA regulation. Moreover, we discuss how similar NR-SAT-based design principles and open-source tools might be readily adapted to study a broad range of dynamic viral or cellular processes.
Collapse
Affiliation(s)
- Edward L. Evans
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Ginger M. Pocock
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Gabriel Einsdorf
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- KNIME GmbH, 78467 Konstanz, Germany;
| | - Ryan T. Behrens
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
| | - Ellen T. A. Dobson
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
| | - Marcel Wiedenmann
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- KNIME GmbH, 78467 Konstanz, Germany;
| | | | - Paul Ahlquist
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Morgridge Institute for Research, Madison, WI 53715, USA
- John and Jeanne Rowe Center for Research in Virology, Madison, WI 53715, USA
| | - Kevin W. Eliceiri
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Nathan M. Sherer
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
| |
Collapse
|
9
|
Li N, Zhang Y, Yao L, Shi Y, Zhao Q, Huang B, Sun Y. A Recombinant Porcine Reproductive and Respiratory Syndrome Virus Stably Expressing DsRed Protein Based on Bacterial Artificial Chromosome System. Front Microbiol 2022; 13:839845. [PMID: 35126342 PMCID: PMC8814527 DOI: 10.3389/fmicb.2022.839845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/03/2022] [Indexed: 11/13/2022] Open
Abstract
Recombinant viruses possessing reporter proteins as tools are widely applied in investigating viral biology because of the convenience for observation. Previously, we generated a recombinant pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) with enhanced green fluorescent protein (EGFP) reporter for monitoring virus spread and screening of neutralizing antibodies. PRRSV with different kinds of reporters can support more application scenarios. Here, we described a new genetically stable infectious clones of a highly pathogenic PRRSV (HP-PRRSV) harboring the DsRed (a red fluorescent protein isolated from the coral Discosoma) gene. In the recombinant infectious clone, the transcription regulatory sequence 2 (TRS2) of PRRSV was inserted between the open reading frame 7 (ORF7) and 3′UTR to drive the transcription of DsRed gene, which makes it a separate transcription unit in the viral genome. Using the bacterial artificial chromosome (BAC) system and cytomegalovirus (CMV) promoter, the recombinant HP-PRRSV with the DsRed insertion was successfully rescued and showed similar growth and replication patterns compared with the wild-type virus in the MARC-145 cells. In addition, the DsRed protein was stably expressed in the recombinant virus for at least 10 passages with consistent fluorescence intensity and density. Using the recombinant HP-PRRSV with DsRed protein, the virus tracking in MARC-145 was observed by live-cell imaging. Meanwhile, quantification of the DsRed fluorescence positive cells by flow cytometry provides an alternative to standard methods for testing the level of PRRSV infection. This recombinant PRRSV with DsRed fluorescence protein expression could be a useful tool for fundamental research on the viral biology and shows the new design for stable expression of foreign genes in PRRSV.
Collapse
Affiliation(s)
- Na Li
- Key Laboratory of Ecological Security, Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Henan Provincial Engineering and Technology Center of Health Products for Livestock and Poultry, School of Life Sciences and Agricultural Engineering, Nanyang Normal University, Nanyang, China
| | - Yiyi Zhang
- Key Laboratory of Ecological Security, Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Henan Provincial Engineering and Technology Center of Health Products for Livestock and Poultry, School of Life Sciences and Agricultural Engineering, Nanyang Normal University, Nanyang, China
| | - Lunguang Yao
- Key Laboratory of Ecological Security, Collaborative Innovation Centre of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project of Henan Province, Henan Provincial Engineering and Technology Center of Health Products for Livestock and Poultry, School of Life Sciences and Agricultural Engineering, Nanyang Normal University, Nanyang, China
| | - Yunpeng Shi
- Shijiazhuang Customs (Huanghua Port), Cangzhou, China
| | - Qin Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Baicheng Huang
- National Research Center for Veterinary Medicine, Luoyang, China
- *Correspondence: Baicheng Huang,
| | - Yani Sun
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Yani Sun,
| |
Collapse
|
10
|
Benner BE, Bruce JW, Kentala JR, Murray M, Becker JT, Garcia-Miranda P, Ahlquist P, Butcher SE, Sherer NM. Perturbing HIV-1 Ribosomal Frameshifting Frequency Reveals a cis Preference for Gag-Pol Incorporation into Assembling Virions. J Virol 2022; 96:e0134921. [PMID: 34643428 PMCID: PMC8754204 DOI: 10.1128/jvi.01349-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/30/2021] [Indexed: 12/29/2022] Open
Abstract
HIV-1 virion production is driven by Gag and Gag-Pol (GP) proteins, with Gag forming the bulk of the capsid and driving budding, while GP binds Gag to deliver the essential virion enzymes protease, reverse transcriptase, and integrase. Virion GP levels are traditionally thought to reflect the relative abundances of GP and Gag in cells (∼1:20), dictated by the frequency of a -1 programmed ribosomal frameshifting (PRF) event occurring in gag-pol mRNAs. Here, we exploited a panel of PRF mutant viruses to show that mechanisms in addition to PRF regulate GP incorporation into virions. First, we show that GP is enriched ∼3-fold in virions relative to cells, with viral infectivity being better maintained at subphysiological levels of GP than when GP levels are too high. Second, we report that GP is more efficiently incorporated into virions when Gag and GP are synthesized in cis (i.e., from the same gag-pol mRNA) than in trans, suggesting that Gag/GP translation and assembly are spatially coupled processes. Third, we show that, surprisingly, virions exhibit a strong upper limit to trans-delivered GP incorporation; an adaptation that appears to allow the virus to temper defects to GP/Gag cleavage that may negatively impact reverse transcription. Taking these results together, we propose a "weighted Goldilocks" scenario for HIV-1 GP incorporation, wherein combined mechanisms of GP enrichment and exclusion buffer virion infectivity over a broad range of local GP concentrations. These results provide new insights into the HIV-1 virion assembly pathway relevant to the anticipated efficacy of PRF-targeted antiviral strategies. IMPORTANCE HIV-1 infectivity requires incorporation of the Gag-Pol (GP) precursor polyprotein into virions during the process of virus particle assembly. Mechanisms dictating GP incorporation into assembling virions are poorly defined, with GP levels in virions traditionally thought to solely reflect relative levels of Gag and GP expressed in cells, dictated by the frequency of a -1 programmed ribosomal frameshifting (PRF) event that occurs in gag-pol mRNAs. Herein, we provide experimental support for a "weighted Goldilocks" scenario for GP incorporation, wherein the virus exploits both random and nonrandom mechanisms to buffer infectivity over a wide range of GP expression levels. These mechanistic data are relevant to ongoing efforts to develop antiviral strategies targeting PRF frequency and/or HIV-1 virion maturation.
Collapse
Affiliation(s)
- Bayleigh E. Benner
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- UW—Madison Microbiology Doctoral Training Program, Madison, Wisconsin, USA
| | - James W. Bruce
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, Wisconsin, USA
| | - Jacob R. Kentala
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Magdalena Murray
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Jordan T. Becker
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Pablo Garcia-Miranda
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Paul Ahlquist
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, Wisconsin, USA
| | - Samuel E. Butcher
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Nathan M. Sherer
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| |
Collapse
|
11
|
Ubiquitination on Lysine 247 of Newcastle Disease Virus Matrix Protein Enhances Viral Replication and Virulence by Driving Nuclear-Cytoplasmic Trafficking. J Virol 2021; 96:e0162921. [PMID: 34705566 DOI: 10.1128/jvi.01629-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The Newcastle disease virus (NDV) matrix (M) protein is the pivotal element for viral assembly, budding and proliferation. It traffics through the cellular nucleus but performs its primary function in the cytoplasm. To investigate the biological importance of M's nuclear-cytoplasmic trafficking and the mechanism involved, the regulatory motif nuclear export signal (NES) and nuclear localization signal (NLS) were deeply analyzed. Here, two types of combined NLS and NES signals were identified within NDV-M. The Herts/33-type M was found to mediate efficient nuclear export and stable virus-like particle (VLP) release, while the LaSota-type M was mostly retained in the nuclei and showed retarded VLP production. Two critical residues, 247 and 263, within the motif were identified and associated with nuclear export efficiency. We identified, for the first time, residue 247 as an important monoubiquitination site, the modification of which regulates the nuclear-cytoplasmic trafficking of NDV-M. Subsequently, mutant LaSota strains were rescued via reverse genetics, which contained either single or double amino acid substitutions that were similar to the M of Herts/33. The rescued rLaSota strains rLaSota-R247K, -S263R, and -DM (double mutation) showed about twofold higher HA titers and 10-fold higher EID50 titers than wild-type (wt) rLaSota. Further, the MDT and ICPI values of those recombinant viruses were slightly higher than that of wt rLaSota probably due to their higher proliferation rates. Our findings contribute to a better understanding of the molecular mechanism of the replication and pathogenicity of NDV, and even those of all other paramyxoviruses. It is beneficial for the development of vaccines and therapies for paramyxoviruses. Importance Newcastle disease virus (NDV) is a pathogen that is lethal to birds and causes heavy losses in the poultry industry worldwide. The World Organization for Animal Health (OIE) ranked ND as the third most significant poultry disease and the eighth most important wildlife disease in the World Livestock Disease Atlas in 2011. The matrix (M) protein of NDV is very important for viral assembly and maturation. It is interesting that M proteins enter the cellular nucleus before performing their primary function in the cytoplasm. We found that NDV-M has a combined nuclear import and export signal. The ubiquitin modification of a lysine residue within this signal is critical for quick, efficient nuclear export and subsequent viral production. Our findings shed new light on viral replication and opens up new possibilities for therapeutics against NDV and other paramyxoviruses; furthermore, we demonstrate a novel approach to improving paramyxovirus vaccines.
Collapse
|
12
|
Li J, Guo Y, Deng Y, Hu L, Li B, Deng S, Zhong J, Xie L, Shi S, Hong X, Zheng X, Cai M, Li M. Subcellular Localization of Epstein-Barr Virus BLLF2 and Its Underlying Mechanisms. Front Microbiol 2021; 12:672192. [PMID: 34367081 PMCID: PMC8339435 DOI: 10.3389/fmicb.2021.672192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/24/2021] [Indexed: 11/13/2022] Open
Abstract
Epstein-Barr virus (EBV), the pathogen of several human malignancies, encodes many proteins required to be transported into the nucleus for viral DNA reproduction and nucleocapsids assembly in the lytic replication cycle. Here, fluorescence microscope, mutation analysis, interspecies heterokaryon assays, co-immunoprecipitation assay, RNA interference, and Western blot were performed to explore the nuclear import mechanism of EBV encoded BLLF2 protein. BLLF2 was shown to be a nucleocytoplasmic shuttling protein neither by a chromosomal region maintenance 1 (CRM1)- nor by a transporter associated with antigen processing (TAP)-dependent pathway. Yet, BLLF2's two functional nuclear localization signals (NLSs), NLS1 (16KRQALETVPHPQNRGR31) and NLS2 (44RRPRPPVAKRRRFPR58), were identified, whereas the predicted NES was nonfunctional. Finally, BLLF2 was proven to transport into the nucleus via a Ran-dependent and importin β1-dependent pathway. This mechanism may contribute to a more extensive insight into the assembly and synthesis of EBV virions in the nucleus, thus affording a new direction for the treatment of viruses.
Collapse
Affiliation(s)
- Jingjing Li
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China.,Department of Oncology, Affiliated Hospital of Weifang Medical University, Weifang, China
| | - Yingjie Guo
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Yangxi Deng
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Li Hu
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Bolin Li
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Shenyu Deng
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Jiayi Zhong
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Li Xie
- Centralab, Shenzhen Center for Chronic Disease Control, Shenzhen, China
| | - Shaoxuan Shi
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Xuejun Hong
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Xuelong Zheng
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Mingsheng Cai
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Meili Li
- The Second Affiliated Hospital, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| |
Collapse
|
13
|
Tavares LA, Januário YC, daSilva LLP. HIV-1 Hijacking of Host ATPases and GTPases That Control Protein Trafficking. Front Cell Dev Biol 2021; 9:622610. [PMID: 34307340 PMCID: PMC8295591 DOI: 10.3389/fcell.2021.622610] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/07/2021] [Indexed: 12/22/2022] Open
Abstract
The human immunodeficiency virus (HIV-1) modifies the host cell environment to ensure efficient and sustained viral replication. Key to these processes is the capacity of the virus to hijack ATPases, GTPases and the associated proteins that control intracellular protein trafficking. The functions of these energy-harnessing enzymes can be seized by HIV-1 to allow the intracellular transport of viral components within the host cell or to change the subcellular distribution of antiviral factors, leading to immune evasion. Here, we summarize how energy-related proteins deviate from their normal functions in host protein trafficking to aid the virus in different phases of its replicative cycle. Recent discoveries regarding the interplay among HIV-1 and host ATPases and GTPases may shed light on potential targets for pharmacological intervention.
Collapse
Affiliation(s)
- Lucas A Tavares
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Yunan C Januário
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Luis L P daSilva
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| |
Collapse
|
14
|
Iarovaia OV, Ioudinkova ES, Velichko AK, Razin SV. Manipulation of Cellular Processes via Nucleolus Hijaking in the Course of Viral Infection in Mammals. Cells 2021; 10:cells10071597. [PMID: 34202380 PMCID: PMC8303250 DOI: 10.3390/cells10071597] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 12/16/2022] Open
Abstract
Due to their exceptional simplicity of organization, viruses rely on the resources, molecular mechanisms, macromolecular complexes, regulatory pathways, and functional compartments of the host cell for an effective infection process. The nucleolus plays an important role in the process of interaction between the virus and the infected cell. The interactions of viral proteins and nucleic acids with the nucleolus during the infection process are universal phenomena and have been described for almost all taxonomic groups. During infection, proteins of the nucleolus in association with viral components can be directly used for the processes of replication and transcription of viral nucleic acids and the assembly and transport of viral particles. In the course of a viral infection, the usurpation of the nucleolus functions occurs and the usurpation is accompanied by profound changes in ribosome biogenesis. Recent studies have demonstrated that the nucleolus is a multifunctional and dynamic compartment. In addition to the biogenesis of ribosomes, it is involved in regulating the cell cycle and apoptosis, responding to cellular stress, repairing DNA, and transcribing RNA polymerase II-dependent genes. A viral infection can be accompanied by targeted transport of viral proteins to the nucleolus, massive release of resident proteins of the nucleolus into the nucleoplasm and cytoplasm, the movement of non-nucleolar proteins into the nucleolar compartment, and the temporary localization of viral nucleic acids in the nucleolus. The interaction of viral and nucleolar proteins interferes with canonical and non-canonical functions of the nucleolus and results in a change in the physiology of the host cell: cell cycle arrest, intensification or arrest of ribosome biogenesis, induction or inhibition of apoptosis, and the modification of signaling cascades involved in the stress response. The nucleolus is, therefore, an important target during viral infection. In this review, we discuss the functional impact of viral proteins and nucleic acid interaction with the nucleolus during infection.
Collapse
|
15
|
Naipauer J, García Solá ME, Salyakina D, Rosario S, Williams S, Coso O, Abba MC, Mesri EA, Lacunza E. A Non-Coding RNA Network Involved in KSHV Tumorigenesis. Front Oncol 2021; 11:687629. [PMID: 34222014 PMCID: PMC8242244 DOI: 10.3389/fonc.2021.687629] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/24/2021] [Indexed: 12/18/2022] Open
Abstract
Regulatory pathways involving non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNA), have gained great relevance due to their role in the control of gene expression modulation. Using RNA sequencing of KSHV Bac36 transfected mouse endothelial cells (mECK36) and tumors, we have analyzed the host and viral transcriptome to uncover the role lncRNA-miRNA-mRNA driven networks in KSHV tumorigenesis. The integration of the differentially expressed ncRNAs, with an exhaustive computational analysis of their experimentally supported targets, led us to dissect complex networks integrated by the cancer-related lncRNAs Malat1, Neat1, H19, Meg3, and their associated miRNA-target pairs. These networks would modulate pathways related to KSHV pathogenesis, such as viral carcinogenesis, p53 signaling, RNA surveillance, and cell cycle control. Finally, the ncRNA-mRNA analysis allowed us to develop signatures that can be used to an appropriate identification of druggable gene or networks defining relevant AIDS-KS therapeutic targets.
Collapse
Affiliation(s)
- Julián Naipauer
- Tumor Biology Program, Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, United States
- UM-CFAR/Sylvester CCC Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Martín E. García Solá
- UM-CFAR/Sylvester CCC Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, United States
- Departamento de Fisiología y Biología Molecular, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Daria Salyakina
- Tumor Biology Program, Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Santas Rosario
- Tumor Biology Program, Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Sion Williams
- UM-CFAR/Sylvester CCC Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, United States
- Neurology Basic Science Division, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Omar Coso
- UM-CFAR/Sylvester CCC Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, United States
- Departamento de Fisiología y Biología Molecular, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Martín C. Abba
- UM-CFAR/Sylvester CCC Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, United States
- Centro de Investigaciones Inmunológicas Básicas y Aplicadas, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Enrique A. Mesri
- Tumor Biology Program, Sylvester Comprehensive Cancer Center and Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, United States
- UM-CFAR/Sylvester CCC Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Ezequiel Lacunza
- UM-CFAR/Sylvester CCC Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, United States
- Centro de Investigaciones Inmunológicas Básicas y Aplicadas, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| |
Collapse
|
16
|
Knoener R, Evans E, Becker JT, Scalf M, Benner B, Sherer NM, Smith LM. Identification of host proteins differentially associated with HIV-1 RNA splice variants. eLife 2021; 10:e62470. [PMID: 33629952 PMCID: PMC7906601 DOI: 10.7554/elife.62470] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/27/2021] [Indexed: 12/12/2022] Open
Abstract
HIV-1 generates unspliced (US), partially spliced (PS), and completely spliced (CS) classes of RNAs, each playing distinct roles in viral replication. Elucidating their host protein 'interactomes' is crucial to understanding virus-host interplay. Here, we present HyPR-MSSV for isolation of US, PS, and CS transcripts from a single population of infected CD4+ T-cells and mass spectrometric identification of their in vivo protein interactomes. Analysis revealed 212 proteins differentially associated with the unique RNA classes, including preferential association of regulators of RNA stability with US and PS transcripts and, unexpectedly, mitochondria-linked proteins with US transcripts. Remarkably, >80 of these factors screened by siRNA knockdown impacted HIV-1 gene expression. Fluorescence microscopy confirmed several to co-localize with HIV-1 US RNA and exhibit changes in abundance and/or localization over the course of infection. This study validates HyPR-MSSV for discovery of viral splice variant protein interactomes and provides an unprecedented resource of factors and pathways likely important to HIV-1 replication.
Collapse
Affiliation(s)
- Rachel Knoener
- Department of Chemistry, University of WisconsinMadisonUnited States
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Edward Evans
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Jordan T Becker
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Mark Scalf
- Department of Chemistry, University of WisconsinMadisonUnited States
| | - Bayleigh Benner
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Nathan M Sherer
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Lloyd M Smith
- Department of Chemistry, University of WisconsinMadisonUnited States
| |
Collapse
|
17
|
The Role of Protein Disorder in Nuclear Transport and in Its Subversion by Viruses. Cells 2020; 9:cells9122654. [PMID: 33321790 PMCID: PMC7764567 DOI: 10.3390/cells9122654] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/08/2020] [Accepted: 12/08/2020] [Indexed: 12/12/2022] Open
Abstract
The transport of host proteins into and out of the nucleus is key to host function. However, nuclear transport is restricted by nuclear pores that perforate the nuclear envelope. Protein intrinsic disorder is an inherent feature of this selective transport barrier and is also a feature of the nuclear transport receptors that facilitate the active nuclear transport of cargo, and the nuclear transport signals on the cargo itself. Furthermore, intrinsic disorder is an inherent feature of viral proteins and viral strategies to disrupt host nucleocytoplasmic transport to benefit their replication. In this review, we highlight the role that intrinsic disorder plays in the nuclear transport of host and viral proteins. We also describe viral subversion mechanisms of the host nuclear transport machinery in which intrinsic disorder is a feature. Finally, we discuss nuclear import and export as therapeutic targets for viral infectious disease.
Collapse
|
18
|
Ramdas P, Sahu AK, Mishra T, Bhardwaj V, Chande A. From Entry to Egress: Strategic Exploitation of the Cellular Processes by HIV-1. Front Microbiol 2020; 11:559792. [PMID: 33343516 PMCID: PMC7746852 DOI: 10.3389/fmicb.2020.559792] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 11/05/2020] [Indexed: 01/23/2023] Open
Abstract
HIV-1 employs a rich arsenal of viral factors throughout its life cycle and co-opts intracellular trafficking pathways. This exquisitely coordinated process requires precise manipulation of the host microenvironment, most often within defined subcellular compartments. The virus capitalizes on the host by modulating cell-surface proteins and cleverly exploiting nuclear import pathways for post entry events, among other key processes. Successful virus–cell interactions are indeed crucial in determining the extent of infection. By evolving defenses against host restriction factors, while simultaneously exploiting host dependency factors, the life cycle of HIV-1 presents a fascinating montage of an ongoing host–virus arms race. Herein, we provide an overview of how HIV-1 exploits native functions of the host cell and discuss recent findings that fundamentally change our understanding of the post-entry replication events.
Collapse
Affiliation(s)
- Pavitra Ramdas
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| | - Amit Kumar Sahu
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| | - Tarun Mishra
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| | - Vipin Bhardwaj
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| | - Ajit Chande
- Molecular Virology Laboratory, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
| |
Collapse
|
19
|
Abstract
The human immunodeficiency virus type 1 (HIV-1) proteome is expressed from alternatively spliced and unspliced genomic RNAs. However, HIV-1 RNAs that are not fully spliced are perceived by the host machinery as defective and are retained in the nucleus. During late infection, HIV-1 bypasses this regulatory mechanism by expression of the Rev protein from a fully spliced mRNA. Once imported into the nucleus, Rev mediates the export of unprocessed HIV-1 RNAs to the cytoplasm, leading to the production of the viral progeny. While regarded as a canonical RNA export factor, Rev has also been linked to HIV-1 RNA translation, stabilization, splicing and packaging. However, Rev's functions beyond RNA export have remained poorly understood. Here, we revisit this paradigmatic protein, reviewing recent data investigating its structure and function. We conclude by asking: what remains unknown about this enigmatic viral protein?
Collapse
Affiliation(s)
| | - Aino Järvelin
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Alfredo Castello
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, 464 Bearsden Road, Glasgow G61 1QH, UK
| |
Collapse
|
20
|
Molenberghs F, Bogers JJ, De Vos WH. Confined no more: Viral mechanisms of nuclear entry and egress. Int J Biochem Cell Biol 2020; 129:105875. [PMID: 33157236 DOI: 10.1016/j.biocel.2020.105875] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 12/14/2022]
Abstract
Viruses are obligatory intracellular parasites. For their efficient replication, many require access to the nuclear interior. Yet, only few viral particles are small enough to passively diffuse through the nuclear pore complexes, calling for alternative strategies to bypass the nuclear envelope barrier. Some viruses will await mitotic nuclear envelope breakdown to gain access, whereas others will exploit more active means, for instance by hijacking nuclear pore transport or by directly targeting constituents of the nuclear envelope so as to remodel and temporarily perturb its integrity. After replication, newly produced viral DNA complexes need to cross the same barrier to exit the nucleus and enter the cytoplasm, where the final stages of virion maturation take place. There are also different flavours to the feat of nuclear egress that vary in delicacy and intensity. In this review, we define the major entry and egress strategies that are exploited by different viruses and describe the molecular details thereof. Ultimately, a deeper understanding of these pathways may help identifying molecular targets for blocking viral reproduction or spreading.
Collapse
Affiliation(s)
- Freya Molenberghs
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences/Medicine and Health Sciences, University of Antwerp, Belgium
| | - Johannes J Bogers
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences/Medicine and Health Sciences, University of Antwerp, Belgium
| | - Winnok H De Vos
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences/Medicine and Health Sciences, University of Antwerp, Belgium.
| |
Collapse
|
21
|
Uddin MH, Zonder JA, Azmi AS. Exportin 1 inhibition as antiviral therapy. Drug Discov Today 2020; 25:1775-1781. [PMID: 32569833 PMCID: PMC7305737 DOI: 10.1016/j.drudis.2020.06.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/21/2020] [Accepted: 06/11/2020] [Indexed: 12/13/2022]
Abstract
Coronavirus 2019 (COVID-19; caused by Severe Acute Respiratory Syndrome Coronavirus 2; SARS-CoV-2) is a currently global health problem. Previous studies showed that blocking nucleocytoplasmic transport with exportin 1 (XPO1) inhibitors originally developed as anticancer drugs can quarantine key viral accessory proteins and genomic materials in the nucleus of host cell and reduce virus replication and immunopathogenicity. These observations support the concept of the inhibition of nuclear export as an effective strategy against an array of viruses, including influenza A, B, and SARS-CoV. Clinical studies using the XPO1 inhibitor selinexor as a therapy for COVID-19 infection are in progress.
Collapse
Affiliation(s)
- Md Hafiz Uddin
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Jeffrey A Zonder
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Asfar S Azmi
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI, USA.
| |
Collapse
|
22
|
Meško M, Lebar T, Dekleva P, Jerala R, Benčina M. Engineering and Rewiring of a Calcium-Dependent Signaling Pathway. ACS Synth Biol 2020; 9:2055-2065. [PMID: 32643923 PMCID: PMC7467823 DOI: 10.1021/acssynbio.0c00133] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
![]()
An important feature of synthetic
biological circuits is their
response to physicochemical signals, which enables the external control
of cellular processes. Calcium-dependent regulation is an attractive
approach for achieving such control, as diverse stimuli induce calcium
influx by activating membrane channel receptors. Most calcium-dependent
gene circuits use the endogenous nuclear factor of activated T-cells
(NFAT) signaling pathway. Here, we employed engineered NFAT transcription
factors to induce the potent and robust activation of exogenous gene
expression in HEK293T cells. Furthermore, we designed a calcium-dependent
transcription factor that does not interfere with NFAT-regulated promoters
and potently activates transcription in several mammalian cell types.
Additionally, we demonstrate that coupling the circuit to a calcium-selective
ion channel resulted in capsaicin- and temperature-controlled gene
expression. This engineered calcium-dependent signaling pathway enables
tightly controlled regulation of gene expression through different
stimuli in mammalian cells and is versatile, adaptable, and useful
for a wide range of therapeutic and diagnostic applications.
Collapse
Affiliation(s)
- Maja Meško
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
- Interfaculty Doctoral Study of Biomedicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Tina Lebar
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Petra Dekleva
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Roman Jerala
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
- EN-FIST Centre of Excellence, Trg Osvobodilne fronte 13, SI-1000 Ljubljana, Slovenia
| | - Mojca Benčina
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
- EN-FIST Centre of Excellence, Trg Osvobodilne fronte 13, SI-1000 Ljubljana, Slovenia
| |
Collapse
|
23
|
Al-Darkazly IAA, Hasan SMR. Extra-Low-Frequency Pulse Stimulated Conformational Change in Blood-Cell Proteins and Consequent Immune Activity Transformation. IEEE JOURNAL OF TRANSLATIONAL ENGINEERING IN HEALTH AND MEDICINE 2020; 8:4100113. [PMID: 31998567 PMCID: PMC6984198 DOI: 10.1109/jtehm.2020.2963894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/12/2019] [Accepted: 12/30/2019] [Indexed: 11/16/2022]
Abstract
Objective: investigation of the extra-low-frequency (ELF) stimulation effect on blood-cell proteins, that causes variation in its electrostatic-state. A hypothesis that this results in the conformational change in the blood-cell proteins which could enhance immune activity is explored. Since HIV-1 and host-cell engage through charge-charge interactions, an electrical-pulse may cause charge redistribution, hypothetically resulting in host-cell proteins to be isolated from viral access. Methods: Buffy coat samples were exposed to ELF square waveform pulses of 5Hz, 10Hz and 1MHz, for 2-hours, and were then examined using immunofluorescence technique. The expression of glycoprotein CD4, and co-receptor protein CCR5, were investigated. Also, the binding activity of the N-terminal domain of CCR5 and the distribution of the nuclear-pore-complex (NPC) transport factor, FGNup153 were investigated. Comparison with control samples were carried out. Results: Increased CD4 count, which could enhance the immune system. In addition, the inability of N-terminus-specific antibody 3A9 to bind to CCR5 N-terminal, could be due to the interactions with the ELF electric-field, which may also hypothetically inhibit HIV-1 attachment. Furthermore, the electrostatic interactions between the ELF pulse and the FGNup153 induces redistribution in its disorder sequence and possibly causes conformational change. This could possibly prevent large virus particle transport through the NPC. Conclusion: Novel concept of ELF stimulation of blood cellular proteins has been developed leading to transformation of immune activity. Clinical-Impact: The translational aspect is the use of ELF as an avenue of electro-medicine and the results are a possible foundation for the clinical application of ELF stimulation in immune response.
Collapse
Affiliation(s)
- Ibtisam A. Abbas Al-Darkazly
- Center for Research in Analog and VLSI Microsystems Design (CRAVE), School of Advanced TechnologyMassey UniversityAuckland0632New Zealand
| | - S. M. Rezaul Hasan
- Center for Research in Analog and VLSI Microsystems Design (CRAVE), School of Advanced TechnologyMassey UniversityAuckland0632New Zealand
| |
Collapse
|
24
|
Saribas AS, Datta PK, Safak M. A comprehensive proteomics analysis of JC virus Agnoprotein-interacting proteins: Agnoprotein primarily targets the host proteins with coiled-coil motifs. Virology 2019; 540:104-118. [PMID: 31765920 DOI: 10.1016/j.virol.2019.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/13/2019] [Accepted: 10/16/2019] [Indexed: 11/29/2022]
Abstract
JC virus (JCV) Agnoprotein (Agno) plays critical roles in successful completion of the viral replication cycle. Understanding its regulatory roles requires a complete map of JCV-host protein interactions. Here, we report the first Agno interactome with host cellular targets utilizing "Two-Strep-Tag" affinity purification system coupled with mass spectroscopy (AP/MS). Proteomics data revealed that Agno primarily targets 501 cellular proteins, most of which contain "coiled-coil" motifs. Agno-host interactions occur in several cellular networks including those involved in protein synthesis and degradation; and cellular transport; and in organelles, including mitochondria, nucleus and ER-Golgi network. Among the Agno interactions, Rab11B, Importin and Crm-1 were first validated biochemically and further characterization was done for Crm-1, using a HIV-1 Rev-M10-like Agno mutant (L33D + E34L), revealing the critical roles of L33 and E34 residues in Crm-1 interaction. This comprehensive proteomics data provides new foundations to unravel the critical regulatory roles of Agno during the JCV life cycle.
Collapse
Affiliation(s)
- A Sami Saribas
- Department of Neuroscience, Laboratory of Molecular Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA, 19140, USA
| | - Prasun K Datta
- Department of Neuroscience, Laboratory of Molecular Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA, 19140, USA
| | - Mahmut Safak
- Department of Neuroscience, Laboratory of Molecular Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA, 19140, USA.
| |
Collapse
|
25
|
Purification and Functional Characterization of a Biologically Active Full-Length Feline Immunodeficiency Virus (FIV) Pr50 Gag. Viruses 2019; 11:v11080689. [PMID: 31357656 PMCID: PMC6723490 DOI: 10.3390/v11080689] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/23/2019] [Accepted: 07/25/2019] [Indexed: 01/01/2023] Open
Abstract
The feline immunodeficiency virus (FIV) full-length Pr50Gag precursor is a key player in the assembly of new viral particles. It is also a critical component of the efficient selection and packaging of two copies of genomic RNA (gRNA) into the newly formed virus particles from a wide pool of cellular and spliced viral RNA. To understand the molecular mechanisms involved during FIV gRNA packaging, we expressed the His6-tagged and untagged recombinant FIV Pr50Gag protein both in eukaryotic and prokaryotic cells. The recombinant Pr50Gag-His6-tag fusion protein was purified from soluble fractions of prokaryotic cultures using immobilized metal affinity chromatography (IMAC). This purified protein was able to assemble in vitro into virus-like particles (VLPs), indicating that it preserved its ability to oligomerize/multimerize. Furthermore, VLPs formed in eukaryotic cells by the FIV full-length Pr50Gag both in the presence and absence of His6-tag could package FIV sub-genomic RNA to similar levels, suggesting that the biological activity of the recombinant full-length Pr50Gag fusion protein was retained in the presence of His6-tag at the carboxy terminus. Successful expression and purification of a biologically active, recombinant full-length Pr50Gag-His6-tag fusion protein will allow study of the intricate RNA-protein interactions involved during FIV gRNA encapsidation.
Collapse
|
26
|
Jayaraman B, Fernandes JD, Yang S, Smith C, Frankel AD. Highly Mutable Linker Regions Regulate HIV-1 Rev Function and Stability. Sci Rep 2019; 9:5139. [PMID: 30914719 PMCID: PMC6435700 DOI: 10.1038/s41598-019-41582-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/05/2019] [Indexed: 11/12/2022] Open
Abstract
HIV-1 Rev is an essential viral regulatory protein that facilitates the nuclear export of intron-containing viral mRNAs. It is organized into structured, functionally well-characterized motifs joined by less understood linker regions. Our recent competitive deep mutational scanning study confirmed many known constraints in Rev’s established motifs, but also identified positions of mutational plasticity, most notably in surrounding linker regions. Here, we probe the mutational limits of these linkers by testing the activities of multiple truncation and mass substitution mutations. We find that these regions possess previously unknown structural, functional or regulatory roles, not apparent from systematic point mutational approaches. Specifically, the N- and C-termini of Rev contribute to protein stability; mutations in a turn that connects the two main helices of Rev have different effects in different contexts; and a linker region which connects the second helix of Rev to its nuclear export sequence has structural requirements for function. Thus, Rev function extends beyond its characterized motifs, and is tuned by determinants within seemingly plastic portions of its sequence. Additionally, Rev’s ability to tolerate many of these massive truncations and substitutions illustrates the overall mutational and functional robustness inherent in this viral protein.
Collapse
Affiliation(s)
- Bhargavi Jayaraman
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Jason D Fernandes
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, 94158, USA.,UCSC Genomics Institute/Howard Hughes Medical Institute, University of Santa Cruz, Santa Cruz, CA, 95060, USA
| | - Shumin Yang
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, 94158, USA.,School of Medicine, Tsinghua University, Beijing, 100084, China
| | - Cynthia Smith
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Alan D Frankel
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, 94158, USA.
| |
Collapse
|
27
|
The Polar Region of the HIV-1 Envelope Protein Determines Viral Fusion and Infectivity by Stabilizing the gp120-gp41 Association. J Virol 2019; 93:JVI.02128-18. [PMID: 30651369 DOI: 10.1128/jvi.02128-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 01/12/2019] [Indexed: 02/06/2023] Open
Abstract
HIV-1 enters cells through binding between viral envelope glycoprotein (Env) and cellular receptors to initiate virus and cell fusion. HIV-1 Env precursor (gp160) is cleaved into two units noncovalently bound to form a trimer on virions, including a surface unit (gp120) and a transmembrane unit (gp41) responsible for virus binding and membrane fusion, respectively. The polar region (PR) at the N terminus of gp41 comprises 17 residues, including 7 polar amino acids. Previous studies suggested that the PR contributes to HIV-1 membrane fusion and infectivity; however, the precise role of the PR in Env-mediated viral entry and the underlying mechanisms remain unknown. Here, we show that the PR is critical for HIV-1 fusion and infectivity by stabilizing Env trimers. Through analyzing the PR sequences of 57,645 HIV-1 isolates, we performed targeted mutagenesis and functional studies of three highly conserved polar residues in the PR (S532P, T534A, and T536A) which have not been characterized previously. We found that single or combined mutations of these three residues abolished or significantly decreased HIV-1 infectivity without affecting viral production. These PR mutations abolished or significantly reduced HIV-1 fusion with target cells and also Env-mediated cell-cell fusion. Three PR mutations containing S532P substantially reduced gp120 and gp41 association, Env trimer stability, and increased gp120 shedding. Furthermore, S532A mutation significantly reduced HIV-1 infectivity and fusogenicity but not Env expression and cleavage. Our findings suggest that the PR of gp41, particularly the key residue S532, is structurally essential for maintaining HIV-1 Env trimer, viral fusogenicity, and infectivity.IMPORTANCE Although extensive studies of the transmembrane unit (gp41) of HIV-1 Env have led to a fusion inhibitor clinically used to block viral entry, the functions of different domains of gp41 in HIV-1 fusion and infectivity are not fully elucidated. The polar region (PR) of gp41 has been proposed to participate in HIV-1 membrane fusion in biochemical analyses, but its role in viral entry and infectivity remain unclear. In our effort to characterize three nucleotide mutations of an HIV-1 RNA element that partially overlaps the PR coding sequence, we identified a novel function of the PR that determines viral fusion and infectivity. We further demonstrated the structural and functional impact of six PR mutations on HIV-1 Env stability, viral fusion, and infectivity. Our findings reveal the previously unappreciated function of the PR and the underlying mechanisms, highlighting the important role of the PR in regulating HIV-1 fusion and infectivity.
Collapse
|
28
|
Pitchai FNN, Ali L, Pillai VN, Chameettachal A, Ashraf SS, Mustafa F, Marquet R, Rizvi TA. Expression, purification, and characterization of biologically active full-length Mason-Pfizer monkey virus (MPMV) Pr78 Gag. Sci Rep 2018; 8:11793. [PMID: 30087395 PMCID: PMC6081465 DOI: 10.1038/s41598-018-30142-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/20/2018] [Indexed: 02/07/2023] Open
Abstract
MPMV precursor polypeptide Pr78Gag orchestrates assembly and packaging of genomic RNA (gRNA) into virus particles. Therefore, we have expressed recombinant full-length Pr78Gag either with or without His6-tag in bacterial as well as eukaryotic cultures and purified the recombinant protein from soluble fractions of the bacterial cultures. The recombinant Pr78Gag protein has the intrinsic ability to assemble in vitro to form virus like particles (VLPs). Consistent with this observation, the recombinant protein could form VLPs in both prokaryotes and eukaryotes. VLPs formed in eukaryotic cells by recombinant Pr78Gag with or without His6-tag can encapsidate MPMV transfer vector RNA, suggesting that the inclusion of the His6-tag to the full-length Pr78Gag did not interfere with its expression or biological function. This study demonstrates the expression and purification of a biologically active, recombinant Pr78Gag, which should pave the way to study RNA-protein interactions involved in the MPMV gRNA packaging process.
Collapse
Affiliation(s)
- Fathima Nuzra Nagoor Pitchai
- Department of Microbiology & Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Lizna Ali
- Department of Microbiology & Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Vineeta Narayana Pillai
- Department of Microbiology & Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Akhil Chameettachal
- Department of Microbiology & Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Syed Salman Ashraf
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Farah Mustafa
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Roland Marquet
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR, 9002, Strasbourg, France.
| | - Tahir Aziz Rizvi
- Department of Microbiology & Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
| |
Collapse
|
29
|
Biochemical and Functional Characterization of Mouse Mammary Tumor Virus Full-Length Pr77 Gag Expressed in Prokaryotic and Eukaryotic Cells. Viruses 2018; 10:v10060334. [PMID: 29912170 PMCID: PMC6024702 DOI: 10.3390/v10060334] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/11/2018] [Accepted: 06/14/2018] [Indexed: 12/15/2022] Open
Abstract
The mouse mammary tumor virus (MMTV) Pr77Gag polypeptide is an essential retroviral structural protein without which infectious viral particles cannot be formed. This process requires specific recognition and packaging of dimerized genomic RNA (gRNA) by Gag during virus assembly. Most of the previous work on retroviral assembly has used either the nucleocapsid portion of Gag, or other truncated Gag derivatives—not the natural substrate for virus assembly. In order to understand the molecular mechanism of MMTV gRNA packaging process, we expressed and purified full-length recombinant Pr77Gag-His6-tag fusion protein from soluble fractions of bacterial cultures. We show that the purified Pr77Gag-His6-tag protein retained the ability to assemble virus-like particles (VLPs) in vitro with morphologically similar immature intracellular particles. The recombinant proteins (with and without His6-tag) could both be expressed in prokaryotic and eukaryotic cells and had the ability to form VLPs in vivo. Most importantly, the recombinant Pr77Gag-His6-tag fusion proteins capable of making VLPs in eukaryotic cells were competent for packaging sub-genomic MMTV RNAs. The successful expression and purification of a biologically active, full-length MMTV Pr77Gag should lay down the foundation towards performing RNA–protein interaction(s), especially for structure-function studies and towards understanding molecular intricacies during MMTV gRNA packaging and assembly processes.
Collapse
|
30
|
Evans EL, Becker JT, Fricke SL, Patel K, Sherer NM. HIV-1 Vif's Capacity To Manipulate the Cell Cycle Is Species Specific. J Virol 2018; 92:e02102-17. [PMID: 29321323 PMCID: PMC5972884 DOI: 10.1128/jvi.02102-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 01/02/2018] [Indexed: 02/06/2023] Open
Abstract
Cells derived from mice and other rodents exhibit profound blocks to HIV-1 virion production, reflecting species-specific incompatibilities between viral Tat and Rev proteins and essential host factors cyclin T1 (CCNT1) and exportin-1 (XPO1, also known as CRM1), respectively. To determine if mouse cell blocks other than CCNT1 and XPO1 affect HIV's postintegration stages, we studied HIV-1NL4-3 gene expression in mouse NIH 3T3 cells modified to constitutively express HIV-1-compatible versions of CCNT1 and XPO1 (3T3.CX cells). 3T3.CX cells supported both Rev-independent and Rev-dependent viral gene expression and produced relatively robust levels of virus particles, confirming that CCNT1 and XPO1 represent the predominant blocks to these stages. Unexpectedly, however, 3T3.CX cells were remarkably resistant to virus-induced cytopathic effects observed in human cell lines, which we mapped to the viral protein Vif and its apparent species-specific capacity to induce G2/M cell cycle arrest. Vif was able to mediate rapid degradation of human APOBEC3G and the PPP2R5D regulatory B56 subunit of the PP2A phosphatase holoenzyme in mouse cells, thus demonstrating that VifNL4-3's modulation of the cell cycle can be functionally uncoupled from some of its other defined roles in CUL5-dependent protein degradation. Vif was also unable to induce G2/M cell cycle arrest in other nonhuman cell types, including cells derived from nonhuman primates, leading us to propose that one or more human-specific cofactors underpin Vif's ability to modulate the cell cycle.IMPORTANCE Cells derived from mice and other rodents exhibit profound blocks to HIV-1 replication, thus hindering the development of a low-cost small-animal model for studying HIV/AIDS. Here, we engineered otherwise-nonpermissive mouse cells to express HIV-1-compatible versions of two species-specific host dependency factors, cyclin T1 (CCNT1) and exportin-1 (XPO1) (3T3.CX cells). We show that 3T3.CX cells rescue HIV-1 particle production but, unexpectedly, are completely resistant to virus-induced cytopathic effects. We mapped these effects to the viral accessory protein Vif, which induces a prolonged G2/M cell cycle arrest followed by apoptosis in human cells. Combined, our results indicate that one or more additional human-specific cofactors govern HIV-1's capacity to modulate the cell cycle, with potential relevance to viral pathogenesis in people and existing animal models.
Collapse
Affiliation(s)
- Edward L Evans
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jordan T Becker
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Stephanie L Fricke
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kishan Patel
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nathan M Sherer
- McArdle Laboratory for Cancer Research, Institute for Molecular Virology, & Carbone Cancer Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| |
Collapse
|