1
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Arribas L, Menéndez-Arias L, Betancor G. May I Help You with Your Coat? HIV-1 Capsid Uncoating and Reverse Transcription. Int J Mol Sci 2024; 25:7167. [PMID: 39000271 PMCID: PMC11241228 DOI: 10.3390/ijms25137167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 06/26/2024] [Accepted: 06/27/2024] [Indexed: 07/16/2024] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) capsid is a protein core formed by multiple copies of the viral capsid (CA) protein. Inside the capsid, HIV-1 harbours all the viral components required for replication, including the genomic RNA and viral enzymes reverse transcriptase (RT) and integrase (IN). Upon infection, the RT transforms the genomic RNA into a double-stranded DNA molecule that is subsequently integrated into the host chromosome by IN. For this to happen, the viral capsid must open and release the viral DNA, in a process known as uncoating. Capsid plays a key role during the initial stages of HIV-1 replication; therefore, its stability is intimately related to infection efficiency, and untimely uncoating results in reverse transcription defects. How and where uncoating takes place and its relationship with reverse transcription is not fully understood, but the recent development of novel biochemical and cellular approaches has provided unprecedented detail on these processes. In this review, we present the latest findings on the intricate link between capsid stability, reverse transcription and uncoating, the different models proposed over the years for capsid uncoating, and the role played by other cellular factors on these processes.
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Affiliation(s)
- Laura Arribas
- Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria, 35016 Las Palmas de Gran Canaria, Spain;
| | - Luis Menéndez-Arias
- Centro de Biología Molecular “Severo Ochoa” (Consejo Superior de Investigaciones Científicas & Universidad Autónoma de Madrid), 28049 Madrid, Spain;
| | - Gilberto Betancor
- Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria, 35016 Las Palmas de Gran Canaria, Spain;
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2
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Narasipura SD, Zayas JP, Ash MK, Reyes A, Shull T, Gambut S, Schneider JR, Lorenzo-Redondo R, Al-Harthi L, Mamede JI. HIV-1 infection promotes neuroinflammation and neuron pathogenesis in novel microglia-containing cerebral organoids. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.13.598579. [PMID: 38915632 PMCID: PMC11195220 DOI: 10.1101/2024.06.13.598579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Cerebral organoids (COs) are a valuable tool to study the intricate interplay between glial cells and neurons in brain development and disease, including HIV-associated neuroinflammation. We developed a novel approach to generate microglia containing COs (CO-iMs) by co-culturing hematopoietic progenitors and induced pluripotent stem cells. This approach allowed for the differentiation of microglia within the organoids concomitantly to the neuronal progenitors. CO- iMs exhibited higher efficiency in generation of CD45 + /CD11b + /Iba-1 + microglia cells compared to conventional COs with physiologically relevant proportion of microglia (∼7%). CO-iMs exhibited substantially higher expression of microglial homeostatic and sensome markers as well as markers for the complement cascade. CO-iMs showed susceptibility to HIV infection resulting in a significant increase in several pro-inflammatory cytokines/chemokines and compromised neuronal function, which were abrogated by addition of antiretrovirals. Thus, CO-iM is a robust model to decipher neuropathogenesis, neurological disorders, and viral infections of brain cells in a 3D culture system.
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3
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Stephens C, Naghavi MH. The host cytoskeleton: a key regulator of early HIV-1 infection. FEBS J 2024; 291:1835-1848. [PMID: 36527282 PMCID: PMC10272291 DOI: 10.1111/febs.16706] [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: 10/21/2022] [Revised: 11/29/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
Due to its central role in cell biology, the cytoskeleton is a key regulator of viral infection, influencing nearly every step of the viral life cycle. In this review, we will discuss the role of two key components of the cytoskeleton, namely the actin and microtubule networks in early HIV-1 infection. We will discuss key contributions to processes ranging from the attachment and entry of viral particles at the cell surface to their arrival and import into the nucleus and identify areas where further research into this complex relationship may yield new insights into HIV-1 pathogenesis.
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Affiliation(s)
- Christopher Stephens
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Mojgan H. Naghavi
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
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4
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Burdick RC, Morse M, Rouzina I, Williams MC, Hu WS, Pathak VK. HIV-1 uncoating requires long double-stranded reverse transcription products. SCIENCE ADVANCES 2024; 10:eadn7033. [PMID: 38657061 PMCID: PMC11042746 DOI: 10.1126/sciadv.adn7033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 03/21/2024] [Indexed: 04/26/2024]
Abstract
HIV-1 cores, which contain the viral genome and replication machinery, must disassemble (uncoat) during viral replication. However, the viral and host factors that trigger uncoating remain unidentified. Recent studies show that infectious cores enter the nucleus and uncoat near the site of integration. Here, we show that efficient uncoating of nuclear cores requires synthesis of a double-stranded DNA (dsDNA) genome >3.5 kb and that the efficiency of uncoating correlates with genome size. Core disruption by capsid inhibitors releases viral DNA, some of which integrates. However, most of the viral DNA is degraded, indicating that the intact core safeguards viral DNA. Atomic force microscopy and core content estimation reveal that synthesis of full-length genomic dsDNA induces substantial internal strain on the core to promote uncoating. We conclude that HIV-1 cores protect viral DNA from degradation by host factors and that synthesis of long double-stranded reverse transcription products is required to trigger efficient HIV-1 uncoating.
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Affiliation(s)
- Ryan C. Burdick
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, 21702, USA
| | - Michael Morse
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA
| | - Mark C. Williams
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Wei-Shau Hu
- Viral Recombination Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, 21702, USA
| | - Vinay K. Pathak
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, 21702, USA
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5
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Guedán A, Burley M, Caroe ER, Bishop KN. HIV-1 Capsid Rapidly Induces Long-Lived CPSF6 Puncta in Non-Dividing Cells, but Similar Puncta Already Exist in Uninfected T-Cells. Viruses 2024; 16:670. [PMID: 38793552 PMCID: PMC11125723 DOI: 10.3390/v16050670] [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: 01/30/2024] [Revised: 04/18/2024] [Accepted: 04/22/2024] [Indexed: 05/26/2024] Open
Abstract
The HIV-1 capsid (CA) protein forms the outer shell of the viral core that is released into the cytoplasm upon infection. CA binds various cellular proteins, including CPSF6, that direct HIV-1 integration into speckle-associated domains in host chromatin. Upon HIV-1 infection, CPSF6 forms puncta in the nucleus. Here, we characterised these CPSF6 puncta further in HeLa cells, T-cells and macrophages and confirmed that integration and reverse transcription are not required for puncta formation. Indeed, we found that puncta formed very rapidly after infection, correlating with the time that CA entered the nucleus. In aphidicolin-treated HeLa cells and macrophages, puncta were detected for the length of the experiment, suggesting that puncta are only lost upon cell division. CA still co-localised with CPSF6 puncta at the latest time points, considerably after the peak of reverse transcription and integration. Intriguingly, the number of puncta induced in macrophages did not correlate with the MOI or the total number of nuclear speckles present in each cell, suggesting that CA/CPSF6 is only directed to a few nuclear speckles. Furthermore, we found that CPSF6 already co-localised with nuclear speckles in uninfected T-cells, suggesting that HIV-1 promotes a natural behaviour of CPSF6.
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Affiliation(s)
| | | | | | - Kate N. Bishop
- Retroviral Replication Laboratory, The Francis Crick Institute, London NW1 1AT, UK; (A.G.); (M.B.); (E.R.C.)
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6
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Taylor IA, Fassati A. The capsid revolution. J Mol Cell Biol 2024; 15:mjad076. [PMID: 38037430 PMCID: PMC11193064 DOI: 10.1093/jmcb/mjad076] [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: 07/25/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 12/02/2023] Open
Abstract
Lenacapavir, targeting the human immunodeficiency virus type-1 (HIV-1) capsid, is the first-in-class antiretroviral drug recently approved for clinical use. The development of Lenacapavir is attributed to the remarkable progress in our understanding of the capsid protein made during the last few years. Considered little more than a component of the virus shell to be shed early during infection, the capsid has been found to be a key player in the HIV-1 life cycle by interacting with multiple host factors, entering the nucleus, and directing integration. Here, we describe the key advances that led to this 'capsid revolution'.
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Affiliation(s)
- Ian A Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Ariberto Fassati
- Division of Infection and Immunity, University College London, London WC1E 6JF, UK
- Institute of Immunity and Transplantation, University College London, London NW3 2PP, UK
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7
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Siew ZY, Asudas E, Khoo CT, Cho GH, Voon K, Fang CM. Fighting nature with nature: antiviral compounds that target retroviruses. Arch Microbiol 2024; 206:130. [PMID: 38416180 DOI: 10.1007/s00203-024-03846-3] [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: 11/16/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 02/29/2024]
Abstract
The human immunodeficiency virus (HIV) is a type of lentivirus that targets the human immune system and leads to acquired immunodeficiency syndrome (AIDS) at a later stage. Up to 2021, there are millions still living with HIV and many have lost their lives. To date, many anti-HIV compounds have been discovered in living organisms, especially plants and marine sponges. However, no treatment can offer a complete cure, but only suppressing it with a life-long medication, known as combined antiretroviral therapy (cART) or highly active antiretroviral therapy (HAART) which are often associated with various adverse effects. Also, it takes many years for a discovered compound to be approved for clinical use. Thus, by employing advanced technologies such as automation, conducting systematic screening and testing protocols may boost the discovery and development of potent and curative therapeutics for HIV infection/AIDS. In this review, we aim to summarize the antiretroviral therapies/compounds and their associated drawbacks since the discovery of azidothymidine. Additionally, we aim to provide an updated analysis of the most recent discoveries of promising antiretroviral candidates, along with an exploration of the current limitations within antiretroviral research. Finally, we intend to glean insightful perspectives and propose future research directions in this crucial area of study.
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Affiliation(s)
- Zhen Yun Siew
- Division of Biomedical Sciences, School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor, Malaysia.
| | - Elishea Asudas
- Division of Biomedical Sciences, School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor, Malaysia
| | - Chia Ting Khoo
- School of Biosciences, University of Nottingham Malaysia, 43500, Semenyih, Selangor, Malaysia
| | - Gang Hyeon Cho
- School of Pharmacy, University of Nottingham Malaysia, 43500, Semenyih, Selangor, Malaysia
| | - Kenny Voon
- Division of Biomedical Sciences, School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor, Malaysia
| | - Chee-Mun Fang
- Division of Biomedical Sciences, School of Pharmacy, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor, Malaysia.
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8
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Gifford LB, Melikyan GB. HIV-1 Capsid Uncoating Is a Multistep Process That Proceeds through Defect Formation Followed by Disassembly of the Capsid Lattice. ACS NANO 2024; 18:2928-2947. [PMID: 38241476 PMCID: PMC10832047 DOI: 10.1021/acsnano.3c07678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 01/17/2024] [Accepted: 01/17/2024] [Indexed: 01/21/2024]
Abstract
The HIV-1 core consists of a cone-shaped capsid shell made of capsid protein (CA) hexamers and pentamers encapsulating the viral genome. HIV-1 capsid disassembly, referred to as uncoating, is important for productive infection; however, the location, timing, and regulation of uncoating remain controversial. Here, we employ amber codon suppression to directly label CA. In addition, a fluid phase fluorescent probe is incorporated into the viral core to detect small defects in the capsid lattice. This double-labeling strategy enables the visualization of uncoating of single cores in vitro and in living cells, which we found to always proceed through at least two distinct steps─the formation of a defect in the capsid lattice that initiates gradual loss of CA below a detectable level. Importantly, intact cores containing the fluid phase and CA fluorescent markers enter and uncoat in the nucleus, as evidenced by a sequential loss of both markers, prior to establishing productive infection. This two-step uncoating process is observed in different cells, including a macrophage line. Notably, the lag between the release of fluid phase marker and terminal loss of CA appears to be independent of the cell type or reverse transcription and is much longer (>5-fold) for nuclear capsids compared to cell-free cores or cores in the cytosol, suggesting that the capsid lattice is stabilized by capsid-binding nuclear factors. Our results imply that intact HIV-1 cores enter the cell nucleus and that uncoating is initiated through a localized defect in the capsid lattice prior to a global loss of CA.
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Affiliation(s)
- Levi B. Gifford
- Department
of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia 30322, United States
| | - Gregory B. Melikyan
- Department
of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia 30322, United States
- Children’s
Healthcare of Atlanta, Atlanta, Georgia 30322, United States
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9
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Hudait A, Voth GA. HIV-1 capsid shape, orientation, and entropic elasticity regulate translocation into the nuclear pore complex. Proc Natl Acad Sci U S A 2024; 121:e2313737121. [PMID: 38241438 PMCID: PMC10823262 DOI: 10.1073/pnas.2313737121] [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: 08/10/2023] [Accepted: 12/06/2023] [Indexed: 01/21/2024] Open
Abstract
Nuclear import and uncoating of the viral capsid are critical steps in the HIV-1 life cycle that serve to transport and release genomic material into the nucleus. Viral core import involves translocating the HIV-1 capsid at the nuclear pore complex (NPC). Notably, the central channel of the NPC appears to often accommodate and allow passage of intact HIV-1 capsid, though mechanistic details of the process remain to be fully understood. Here, we investigate the molecular interactions that operate in concert between the HIV-1 capsid and the NPC that regulate capsid translocation through the central channel. To this end, we develop a "bottom-up" coarse-grained (CG) model of the human NPC from recently released cryo-electron tomography structure and then construct composite membrane-embedded CG NPC models. We find that successful translocation from the cytoplasmic side to the NPC central channel is contingent on the compatibility of the capsid morphology and channel dimension and the proper orientation of the capsid approach to the channel from the cytoplasmic side. The translocation dynamics is driven by maximizing the contacts between phenylalanine-glycine nucleoporins at the central channel and the capsid. For the docked intact capsids, structural analysis reveals correlated striated patterns of lattice disorder likely related to the intrinsic capsid elasticity. Uncondensed genomic material inside the docked capsid augments the overall lattice disorder of the capsid. Our results suggest that the intrinsic "elasticity" can also aid the capsid to adapt to the stress and remain structurally intact during translocation.
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Affiliation(s)
- Arpa Hudait
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, IL60637
| | - Gregory A. Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, IL60637
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10
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Gambut S, Hope TJ, Mamede JI. Infectious Virus Tracking by Fluorescent Live Cell Imaging in Primary Cells. Methods Mol Biol 2024; 2807:3-14. [PMID: 38743217 DOI: 10.1007/978-1-0716-3862-0_1] [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: 05/16/2024]
Abstract
To successfully infect a cell, HIV-1 has to overcome several host barriers while exploiting cellular cofactors. HIV-1 infection is highly inefficient with the great majority of viral particles not being able to successfully integrate into the target cell genome. Nonproductive HIV-1 particles are degraded or accumulated in cellular compartments. Thus, it becomes hard to distinguish between viral behaviors that lead to effectively infecting the cell from the ones that do not by using traditional methods. Here, we describe the infectious virus tracking method that detects and quantifies individual fluorescent viral particles over time and links viral particle behavior to its infectivity. This method employs live-cell imaging at ultra-low MOIs to detect the outcome of infection for every HIV-1 particle.
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Affiliation(s)
- Stephanie Gambut
- Department of Microbial Pathogens & Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Thomas J Hope
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, USA
- Department of Cell & Developmental Biology, Northwestern University, Chicago, IL, USA
- Department of Obstetrics & Gynecology, Northwestern University, Chicago, IL, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Chemistry of Life Processes Institute, Northwestern University, Chicago, IL, USA
| | - João I Mamede
- Department of Microbial Pathogens & Immunity, Rush University Medical Center, Chicago, IL, USA.
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11
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Jang S, Engelman AN. Capsid-host interactions for HIV-1 ingress. Microbiol Mol Biol Rev 2023; 87:e0004822. [PMID: 37750702 PMCID: PMC10732038 DOI: 10.1128/mmbr.00048-22] [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: 09/27/2023] Open
Abstract
The HIV-1 capsid, composed of approximately 1,200 copies of the capsid protein, encases genomic RNA alongside viral nucleocapsid, reverse transcriptase, and integrase proteins. After cell entry, the capsid interacts with a myriad of host factors to traverse the cell cytoplasm, pass through the nuclear pore complex (NPC), and then traffic to chromosomal sites for viral DNA integration. Integration may very well require the dissolution of the capsid, but where and when this uncoating event occurs remains hotly debated. Based on size constraints, a long-prevailing view was that uncoating preceded nuclear transport, but recent research has indicated that the capsid may remain largely intact during nuclear import, with perhaps some structural remodeling required for NPC traversal. Completion of reverse transcription in the nucleus may further aid capsid uncoating. One canonical type of host factor, typified by CPSF6, leverages a Phe-Gly (FG) motif to bind capsid. Recent research has shown these peptides reside amid prion-like domains (PrLDs), which are stretches of protein sequence devoid of charged residues. Intermolecular PrLD interactions along the exterior of the capsid shell impart avid host factor binding for productive HIV-1 infection. Herein we overview capsid-host interactions implicated in HIV-1 ingress and discuss important research questions moving forward. Highlighting clinical relevance, the long-acting ultrapotent inhibitor lenacapavir, which engages the same capsid binding pocket as FG host factors, was recently approved to treat people living with HIV.
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Affiliation(s)
- Sooin Jang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Alan N. Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
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12
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Cabrera-Rodríguez R, Pérez-Yanes S, Lorenzo-Sánchez I, Trujillo-González R, Estévez-Herrera J, García-Luis J, Valenzuela-Fernández A. HIV Infection: Shaping the Complex, Dynamic, and Interconnected Network of the Cytoskeleton. Int J Mol Sci 2023; 24:13104. [PMID: 37685911 PMCID: PMC10487602 DOI: 10.3390/ijms241713104] [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: 08/08/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
HIV-1 has evolved a plethora of strategies to overcome the cytoskeletal barrier (i.e., actin and intermediate filaments (AFs and IFs) and microtubules (MTs)) to achieve the viral cycle. HIV-1 modifies cytoskeletal organization and dynamics by acting on associated adaptors and molecular motors to productively fuse, enter, and infect cells and then traffic to the cell surface, where virions assemble and are released to spread infection. The HIV-1 envelope (Env) initiates the cycle by binding to and signaling through its main cell surface receptors (CD4/CCR5/CXCR4) to shape the cytoskeleton for fusion pore formation, which permits viral core entry. Then, the HIV-1 capsid is transported to the nucleus associated with cytoskeleton tracks under the control of specific adaptors/molecular motors, as well as HIV-1 accessory proteins. Furthermore, HIV-1 drives the late stages of the viral cycle by regulating cytoskeleton dynamics to assure viral Pr55Gag expression and transport to the cell surface, where it assembles and buds to mature infectious virions. In this review, we therefore analyze how HIV-1 generates a cell-permissive state to infection by regulating the cytoskeleton and associated factors. Likewise, we discuss the relevance of this knowledge to understand HIV-1 infection and pathogenesis in patients and to develop therapeutic strategies to battle HIV-1.
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Affiliation(s)
- Romina Cabrera-Rodríguez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Silvia Pérez-Yanes
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Iria Lorenzo-Sánchez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Rodrigo Trujillo-González
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
- Analysis Department, Faculty of Mathematics, Universidad de La Laguna (ULL), 38200 La Laguna, Spain
| | - Judith Estévez-Herrera
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Jonay García-Luis
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
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13
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Masenga SK, Mweene BC, Luwaya E, Muchaili L, Chona M, Kirabo A. HIV-Host Cell Interactions. Cells 2023; 12:1351. [PMID: 37408185 DOI: 10.3390/cells12101351] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 07/07/2023] Open
Abstract
The development of antiretroviral drugs (ARVs) was a great milestone in the management of HIV infection. ARVs suppress viral activity in the host cell, thus minimizing injury to the cells and prolonging life. However, an effective treatment has remained elusive for four decades due to the successful immune evasion mechanisms of the virus. A thorough understanding of the molecular interaction of HIV with the host cell is essential in the development of both preventive and curative therapies for HIV infection. This review highlights several inherent mechanisms of HIV that promote its survival and propagation, such as the targeting of CD4+ lymphocytes, the downregulation of MHC class I and II, antigenic variation and an envelope complex that minimizes antibody access, and how they collaboratively render the immune system unable to mount an effective response.
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Affiliation(s)
- Sepiso K Masenga
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
- Vanderbilt University Medical Center, Department of Medicine, Division of Clinical Pharmacology, Room 536 Robinson Research Building, Nashville, TN 37232-6602, USA
| | - Bislom C Mweene
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
| | - Emmanuel Luwaya
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
| | - Lweendo Muchaili
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
| | - Makondo Chona
- HAND Research Group, School of Medicine and Health Sciences, Mulungushi University, Livingstone Campus, Livingstone 10101, Zambia
| | - Annet Kirabo
- Vanderbilt University Medical Center, Department of Medicine, Division of Clinical Pharmacology, Room 536 Robinson Research Building, Nashville, TN 37232-6602, USA
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14
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Tough Way In, Tough Way Out: The Complex Interplay of Host and Viral Factors in Nucleocytoplasmic Trafficking during HIV-1 Infection. Viruses 2022; 14:v14112503. [PMID: 36423112 PMCID: PMC9696704 DOI: 10.3390/v14112503] [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: 08/31/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) is a retrovirus that integrates its reverse-transcribed genome as proviral DNA into the host genome to establish a successful infection. The viral genome integration requires safeguarding the subviral complexes, reverse transcription complex (RTC) and preintegration complex (PIC), in the cytosol from degradation, presumably effectively secured by the capsid surrounding these complexes. An intact capsid, however, is a large structure, which raises concerns about its translocation from cytoplasm to nucleus crossing the nuclear membrane, guarded by complex nuclear pore structures, which do not allow non-specific transport of large molecules. In addition, the generation of new virions requires the export of incompletely processed viral RNA from the nucleus to the cytoplasm, an event conventionally not permitted through mammalian nuclear membranes. HIV-1 has evolved multiple mechanisms involving redundant host pathways by liaison with the cell's nucleocytoplasmic trafficking system, failure of which would lead to the collapse of the infection cycle. This review aims to assemble the current developments in temporal and spatial events governing nucleocytoplasmic transport of HIV-1 factors. Discoveries are anticipated to serve as the foundation for devising host-directed therapies involving selective abolishment of the critical interactomes between viral proteins and their host equivalents.
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15
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Genetic Code Expansion and Bio-Orthogonal Labeling Reveal Intact HIV-1 Capsids inside the Nucleus. mBio 2022; 13:e0234622. [PMID: 36098403 PMCID: PMC9600262 DOI: 10.1128/mbio.02346-22] [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] [Indexed: 11/20/2022] Open
Abstract
Microscopy is one of the few techniques that can directly observe the HIV-1 capsid as it traverses the cell. However, an extrinsic or intrinsic label is needed to facilitate detection and this can perturb capsid behavior. Now, S. Schifferdecker, V. Zila, T. G. Muller, V. Sakin, et al. (mBio:e0195922, 2022, https://journals.asm.org/doi/10.1128/mbio.01959-22) have developed an ingenious direct labeling technology that uses genetic code expansion and click chemistry to produce infectious viruses whose capsids are labeled with only a single modified amino acid. Using this new system, together with electron tomography, the authors demonstrate that the capsid remains intact during its transport into the nucleus of T cells, supporting a late model of uncoating immediately before integration. Combining direct-labeled capsids with fluorescent nonstructural viral proteins or host cofactors promises to be hugely enabling for future studies. Moreover, the potential to install a bio-orthogonal label site specifically in the capsid is likely to have exciting applications beyond imaging.
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16
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Complex Relationships between HIV-1 Integrase and Its Cellular Partners. Int J Mol Sci 2022; 23:ijms232012341. [PMID: 36293197 PMCID: PMC9603942 DOI: 10.3390/ijms232012341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/09/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
RNA viruses, in pursuit of genome miniaturization, tend to employ cellular proteins to facilitate their replication. HIV-1, one of the most well-studied retroviruses, is not an exception. There is numerous evidence that the exploitation of cellular machinery relies on nucleic acid-protein and protein-protein interactions. Apart from Vpr, Vif, and Nef proteins that are known to regulate cellular functioning via interaction with cell components, another viral protein, integrase, appears to be crucial for proper virus-cell dialog at different stages of the viral life cycle. The goal of this review is to summarize and systematize existing data on known cellular partners of HIV-1 integrase and their role in the HIV-1 life cycle.
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17
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Two-step recognition of HIV-1 DNA in the cytosol. Trends Microbiol 2022; 31:430-431. [PMID: 36153261 DOI: 10.1016/j.tim.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 11/23/2022]
Abstract
Retroviral DNA induces the production of interferons. A new study by Yoh et al. showed that the host factor 'PQBP1' primes immune-recognition of retroviral DNA by recruiting the cytosolic DNA scavenger 'cGAS' to the HIV-1 capsid. Their findings support the importance of innate immune sensing in HIV-1 infection.
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18
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Monette A, Niu M, Nijhoff Asser M, Gorelick RJ, Mouland AJ. Scaffolding viral protein NC nucleates phase separation of the HIV-1 biomolecular condensate. Cell Rep 2022; 40:111251. [PMID: 36001979 DOI: 10.1016/j.celrep.2022.111251] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/20/2022] [Accepted: 08/01/2022] [Indexed: 11/26/2022] Open
Abstract
Membraneless biomolecular condensates (BMCs) contribute to the replication of a growing number of viruses but remain to be functionally characterized. Previously, we demonstrated that pan-retroviral nucleocapsid (NC) proteins phase separated into condensates regulating virus assembly. Here we discover that intrinsically disordered human immunodeficiency virus-type 1 (HIV-1) core proteins condense with the viral genomic RNA (vRNA) to assemble as BMCs attaining a geometry characteristic of viral reverse transcription complexes. We explore the predisposition, mechanisms, and pharmacologic sensitivity of HIV-1 core BMCs in living cells. HIV-1 vRNA-interacting NC condensates were found to be scaffolds onto which client capsid, reverse transcriptase, and integrase condensates assemble. HIV-1 core BMCs exhibit fundamental characteristics of BMCs and are drug-sensitive. Lastly, protease-mediated maturation of Gag and Gag-Pol precursor proteins yield abundant and visible BMCs in cells. This study redefines HIV-1 core components as fluid BMCs and advances our understanding of the nature of viral cores during ingress.
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Affiliation(s)
- Anne Monette
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.
| | - Meijuan Niu
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada
| | - Maya Nijhoff Asser
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada; Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada.
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19
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Direct Capsid Labeling of Infectious HIV-1 by Genetic Code Expansion Allows Detection of Largely Complete Nuclear Capsids and Suggests Nuclear Entry of HIV-1 Complexes via Common Routes. mBio 2022; 13:e0195922. [PMID: 35972146 PMCID: PMC9600849 DOI: 10.1128/mbio.01959-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The cone-shaped mature HIV-1 capsid is the main orchestrator of early viral replication. After cytosolic entry, it transports the viral replication complex along microtubules toward the nucleus. While it was initially believed that the reverse transcribed genome is released from the capsid in the cytosol, recent observations indicate that a high amount of capsid protein (CA) remains associated with subviral complexes during import through the nuclear pore complex (NPC). Observation of postentry events via microscopic detection of HIV-1 CA is challenging, since epitope shielding limits immunodetection and the genetic fragility of CA hampers direct labeling approaches. Here, we present a minimally invasive strategy based on genetic code expansion and click chemistry that allows for site-directed fluorescent labeling of HIV-1 CA, while retaining virus morphology and infectivity. Thereby, we could directly visualize virions and subviral complexes using advanced microscopy, including nanoscopy and correlative imaging. Quantification of signal intensities of subviral complexes revealed an amount of CA associated with nuclear complexes in HeLa-derived cells and primary T cells consistent with a complete capsid and showed that treatment with the small molecule inhibitor PF74 did not result in capsid dissociation from nuclear complexes. Cone-shaped objects detected in the nucleus by electron tomography were clearly identified as capsid-derived structures by correlative microscopy. High-resolution imaging revealed dose-dependent clustering of nuclear capsids, suggesting that incoming particles may follow common entry routes.
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20
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Yoh SM, Mamede JI, Lau D, Ahn N, Sánchez-Aparicio MT, Temple J, Tuckwell A, Fuchs NV, Cianci GC, Riva L, Curry H, Yin X, Gambut S, Simons LM, Hultquist JF, König R, Xiong Y, García-Sastre A, Böcking T, Hope TJ, Chanda SK. Recognition of HIV-1 capsid by PQBP1 licenses an innate immune sensing of nascent HIV-1 DNA. Mol Cell 2022; 82:2871-2884.e6. [PMID: 35809572 PMCID: PMC9552964 DOI: 10.1016/j.molcel.2022.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 03/22/2022] [Accepted: 06/07/2022] [Indexed: 12/21/2022]
Abstract
We have previously described polyglutamine-binding protein 1 (PQBP1) as an adapter required for the cyclic GMP-AMP synthase (cGAS)-mediated innate response to the human immunodeficiency virus 1 (HIV-1) and other lentiviruses. Cytoplasmic HIV-1 DNA is a transient and low-abundance pathogen-associated molecular pattern (PAMP), and the mechanism for its detection and verification is not fully understood. Here, we show a two-factor authentication strategy by the innate surveillance machinery to selectively respond to the low concentration of HIV-1 DNA, while distinguishing these species from extranuclear DNA molecules. We find that, upon HIV-1 infection, PQBP1 decorates the intact viral capsid, and this serves as a primary verification step for the viral nucleic acid cargo. As reverse transcription and capsid disassembly initiate, cGAS is recruited to the capsid in a PQBP1-dependent manner. This positions cGAS at the site of PAMP generation and sanctions its response to a low-abundance DNA PAMP.
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Affiliation(s)
- Sunnie M Yoh
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA.
| | - João I Mamede
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL 60612, USA
| | - Derrick Lau
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Narae Ahn
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Maria T Sánchez-Aparicio
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Joshua Temple
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Andrew Tuckwell
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Nina V Fuchs
- Host-Pathogen Interaction, Paul-Ehrlich-Institut, 63225 Langen, Germany
| | - Gianguido C Cianci
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Laura Riva
- Calibr, a Division of The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Heather Curry
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Xin Yin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, P.R. China
| | - Stéphanie Gambut
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL 60612, USA
| | - Lacy M Simons
- Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Center for Pathogen Genomics and Microbial Evolution, Institute for Global Health, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Judd F Hultquist
- Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Center for Pathogen Genomics and Microbial Evolution, Institute for Global Health, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Renate König
- Host-Pathogen Interaction, Paul-Ehrlich-Institut, 63225 Langen, Germany
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pathology, Molecular, and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Till Böcking
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Thomas J Hope
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sumit K Chanda
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA.
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21
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Localization and functions of native and eGFP-tagged capsid proteins in HIV-1 particles. PLoS Pathog 2022; 18:e1010754. [PMID: 35951676 PMCID: PMC9426931 DOI: 10.1371/journal.ppat.1010754] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 08/30/2022] [Accepted: 07/21/2022] [Indexed: 12/24/2022] Open
Abstract
In infectious HIV-1 particles, the capsid protein (CA) forms a cone-shaped shell called the capsid, which encases the viral ribonucleoprotein complex (vRNP). Following cellular entry, the capsid is disassembled through a poorly understood process referred to as uncoating, which is required to release the reverse transcribed HIV-1 genome for integration into host chromatin. Whereas single virus imaging using indirect CA labeling techniques suggested uncoating to occur in the cytoplasm or at the nuclear pore, a recent study using eGFP-tagged CA reported uncoating in the nucleus. To delineate the HIV-1 uncoating site, we investigated the mechanism of eGFP-tagged CA incorporation into capsids and the utility of this fluorescent marker for visualizing HIV-1 uncoating. We find that virion incorporated eGFP-tagged CA is effectively excluded from the capsid shell, and that a subset of the tagged CA is vRNP associated. These results thus imply that eGFP-tagged CA is not a direct marker for capsid uncoating. We further show that native CA co-immunoprecipitates with vRNP components, providing a basis for retention of eGFP-tagged and untagged CA by sub-viral complexes in the nucleus. Moreover, we find that functional viral replication complexes become accessible to integrase-interacting host factors at the nuclear pore, leading to inhibition of infection and demonstrating capsid permeabilization prior to nuclear import. Finally, we find that HIV-1 cores containing a mixture of wild-type and mutant CA interact differently with cytoplasmic versus nuclear pools of the CA-binding host cofactor CPSF6. Our results suggest that capsid remodeling (including a loss of capsid integrity) is the predominant pathway for HIV-1 nuclear entry and provide new insights into the mechanism of CA retention in the nucleus via interaction with vRNP components. The timing, location and mechanisms of HIV-1 capsid disassembly which is referred to as uncoating remains unclear. Direct labeling of HIV-1 capsids, by incorporating a few green fluorescent proteins (GFP) tagged capsid protein (CA) into virions allows to image the spatio-temporal loss of HIV-1 CA during virus infection. However, the localization and functions of a few virion incorporated eGFP-tagged CA proteins remain unclear, since <50% of virus packaged CA proteins participate to form the conical capsid shell that protects the HIV-1 genome. Here we developed several approaches to test the localization and function of eGFP-tagged CA proteins in virions. We found that eGFP-tagged CA proteins are excluded from the conical capsid shell and that a subset of these proteins is associated with the viral ribonucleoprotein complex (vRNPs), through direct interactions between CA and vRNP components. eGFP-tagged CA is retained in the nucleus by virtue of vRNP association and is unlikely to report on HIV-1 capsid disassembly. We also found that HIV-1 capsids become permeabilized and are remodeled during their transport into the nucleus. Our study provides new insights into the ability of CA to interact with vRNPs for its retention in the nucleus and highlights capsid remodeling as a preferred pathway for HIV-1 entry into the nucleus.
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22
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Müller TG, Zila V, Müller B, Kräusslich HG. Nuclear Capsid Uncoating and Reverse Transcription of HIV-1. Annu Rev Virol 2022; 9:261-284. [PMID: 35704745 DOI: 10.1146/annurev-virology-020922-110929] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
After cell entry, human immunodeficiency virus type 1 (HIV-1) replication involves reverse transcription of the RNA genome, nuclear import of the subviral complex without nuclear envelope breakdown, and integration of the viral complementary DNA into the host genome. Here, we discuss recent evidence indicating that completion of reverse transcription and viral genome uncoating occur in the nucleus rather than in the cytoplasm, as previously thought, and suggest a testable model for nuclear import and uncoating. Multiple recent studies indicated that the cone-shaped capsid, which encases the genome and replication proteins, not only serves as a reaction container for reverse transcription and as a shield from innate immune sensors but also may constitute the elusive HIV-1 nuclear import factor. Rupture of the capsid may be triggered in the nucleus by completion of reverse transcription, by yet-unknown nuclear factors, or by physical damage, and it appears to occur in close temporal and spatial association with the integration process. Expected final online publication date for the Annual Review of Virology, Volume 9 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Thorsten G Müller
- Department of Infectious Diseases, Virology, Heidelberg University, Heidelberg, Germany;
| | - Vojtech Zila
- Department of Infectious Diseases, Virology, Heidelberg University, Heidelberg, Germany;
| | - Barbara Müller
- Department of Infectious Diseases, Virology, Heidelberg University, Heidelberg, Germany;
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, Heidelberg University, Heidelberg, Germany; .,German Center for Infection Research, Heidelberg, Germany
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23
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Troyano-Hernáez P, Reinosa R, Holguín Á. HIV Capsid Protein Genetic Diversity Across HIV-1 Variants and Impact on New Capsid-Inhibitor Lenacapavir. Front Microbiol 2022; 13:854974. [PMID: 35495642 PMCID: PMC9039614 DOI: 10.3389/fmicb.2022.854974] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/09/2022] [Indexed: 12/17/2022] Open
Abstract
The HIV p24 capsid protein has an essential, structural, and functional role in the viral replication cycle, being an interesting target for vaccine design, diagnostic tests, and new antiretroviral drugs (ARVs). The HIV-1 variability poses a challenge for the accuracy and efficiency of diagnostic and treatment tools. This study analyzes p24 diversity among HIV-1 variants and within its secondary structure in HIV-1 M, O, P, and N groups. All available HIV-1 p24 nucleotide sequences were downloaded from the Los Alamos HIV Sequence Database, selecting 23,671 sequences belonging to groups O, N, P, and M (9 subtypes, 7 sub-sub types, and 109 circulating recombinant forms or CRFs). Using a bioinformatics tool developed in our laboratory (EpiMolBio program), we analyzed the amino acid conservation compared to the HXB2 subtype B reference sequence and the V-markers, or amino acid changes that were specific for each variant with at least 10 available sequences. We inferred the p24 consensus sequence for HIV-1 and for each group to analyze the overall conservation in p24 main structural regions, reporting the percentage of substitutions per variant affecting the capsid assembly and molecule-binding, including those associated with resistance to the new capsid-inhibitor lenacapavir, and the key residues involved in lenacapavir-p24 interaction, according to the bibliography. Although the overall structure of p24 was highly conserved, the conservation in the secondary structure varied between HIV-1 variants and the type of secondary structure. All HIV-1 variants presented >80% amino acid conservation vs. HXB2 reference sequence, except for group M sub-subtype F1 (69.27%). Mutants affecting the capsid assembly or lenacapavir capsid-binding were found in <1% of the p24 consensus sequence. Our study reports the HIV-1 variants carrying 14 unique single V-markers in 9/38 group M variants and the level of p24 conservation in each secondary structure region among the 4 HIV-1 groups and group M variants, revealing no natural resistance to lenacapavir in any HIV-1 variant. We present a thorough analysis of p24 variability among all HIV-1 variants circulating to date. Since p24 genetic variability can impact the viral replication cycle and the efficacy of new p24-based diagnostic, therapeutic, and vaccine strategies, conservation studies must consider all HIV-1 variants circulating worldwide.
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Affiliation(s)
- Paloma Troyano-Hernáez
- HIV-1 Molecular Epidemiology Laboratory, Department of Microbiology, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, CIBER en Epidemiología y Salud Pública (CIBERESP), Red en Investigación Translacional en Infecciones Pediátricas (RITIP), Madrid, Spain
| | - Roberto Reinosa
- HIV-1 Molecular Epidemiology Laboratory, Department of Microbiology, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, CIBER en Epidemiología y Salud Pública (CIBERESP), Red en Investigación Translacional en Infecciones Pediátricas (RITIP), Madrid, Spain
| | - África Holguín
- HIV-1 Molecular Epidemiology Laboratory, Department of Microbiology, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, CIBER en Epidemiología y Salud Pública (CIBERESP), Red en Investigación Translacional en Infecciones Pediátricas (RITIP), Madrid, Spain
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24
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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.
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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.)
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Dharan A, Campbell EM. Teaching old dogmas new tricks: recent insights into the nuclear import of HIV-1. Curr Opin Virol 2022; 53:101203. [PMID: 35121335 PMCID: PMC9175559 DOI: 10.1016/j.coviro.2022.101203] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 01/10/2022] [Indexed: 01/08/2023]
Abstract
A hallmark feature of lentiviruses, which separates them from other members of the retrovirus family, is their ability to infect non-dividing cells by traversing the nuclear pore complex. The viral determinant that mediates HIV-1 nuclear import is the viral capsid (CA) protein, which forms the conical core protecting the HIV-1 genome in a mature virion. Recently, a series of novel approaches developed to monitor post-fusion events in infection have challenged previous textbook models of the viral life cycle, which envisage reverse transcription and disassembly of the capsid core as events that complete in the cytoplasm. In this review, we summarize these recent findings and describe their implications on our understanding of the spatiotemporal staging of HIV-1 infection with a focus on the nuclear import and its implications in other aspects of the viral lifecycle.
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Affiliation(s)
- Adarsh Dharan
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, IL, USA
| | - Edward M Campbell
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, IL, USA.
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Ma Y, Mao G, Wu G, Zhang XE. Single-Particle Tracking Reveals the Interplay between HIV-1 Reverse Transcription and Uncoating. Anal Chem 2022; 94:2648-2654. [PMID: 35080851 DOI: 10.1021/acs.analchem.1c05199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reverse transcription uses the reverse transcriptase enzyme to synthesize deoxyribonucleic acid (DNA) from a ribonucleic acid (RNA) template. This plays an essential role in viral replication. There are still, however, many unknown facts regarding the timing and dynamic processes involved in this life stage. Here, three types of dual-fluorescence human immunodeficiency virus type-1 (HIV-1) particles were constructed with high infectivity, and the sequential process of reverse transcription was observed by real-time imaging of a single HIV-1 particle. Viral uncoating occurred at 60-120 min post infection. Subsequently, at 120-180 min post infection, the viral genome was separated into two parts and reverse-transcribed to generate a DNA product. Nevirapine (NVP), a reverse transcriptase inhibitor, can delay the dynamic process. This study revealed a delicate, sequential, and complex relationship between uncoating and reverse transcription, which may facilitate the development of antiviral drugs.
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Affiliation(s)
- Yingxin Ma
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Guobin Mao
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Guoqiang Wu
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Xian-En Zhang
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.,National Key Laboratory of Biomacromolecules Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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Insights into HIV uncoating from single-particle imaging techniques. Biophys Rev 2022; 14:23-32. [PMID: 35340594 PMCID: PMC8921429 DOI: 10.1007/s12551-021-00922-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 11/23/2021] [Indexed: 01/13/2023] Open
Abstract
Human immunodeficiency virus (HIV) is the most extensively researched human pathogen. Despite this massive scientific endeavour, several fundamental viral processes remain enigmatic. One such critical process is uncoating-the event that releases the viral genome from the proteinaceous shell of the capsid during infection. While this process is conceptually simple, the molecular underpinnings, timing, regulation, and cellular location of uncoating remain contentious. This review describes the hurdles that have limited our understanding in this area and presents recently deployed in vitro and in cellulo techniques that have been developed expressly with the aim of directly visualising capsid uncoating at the single-particle level and understanding the mechanics behind this essential aspect of HIV infection.
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28
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Fullerene Derivatives Prevent Packaging of Viral Genomic RNA into HIV-1 Particles by Binding Nucleocapsid Protein. Viruses 2021; 13:v13122451. [PMID: 34960720 PMCID: PMC8705927 DOI: 10.3390/v13122451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 02/02/2023] Open
Abstract
Fullerene derivatives with hydrophilic substituents have been shown to exhibit a range of biological activities, including antiviral ones. For a long time, the anti-HIV activity of fullerene derivatives was believed to be due to their binding into the hydrophobic pocket of HIV-1 protease, thereby blocking its activity. Recent work, however, brought new evidence of a novel, protease-independent mechanism of fullerene derivatives' action. We studied in more detail the mechanism of the anti-HIV-1 activity of N,N-dimethyl[70]fulleropyrrolidinium iodide fullerene derivatives. By using a combination of in vitro and cell-based approaches, we showed that these C70 derivatives inhibited neither HIV-1 protease nor HIV-1 maturation. Instead, our data indicate effects of fullerene C70 derivatives on viral genomic RNA packaging and HIV-1 cDNA synthesis during reverse transcription-without impairing reverse transcriptase activity though. Molecularly, this could be explained by a strong binding affinity of these fullerene derivatives to HIV-1 nucleocapsid domain, preventing its proper interaction with viral genomic RNA, thereby blocking reverse transcription and HIV-1 infectivity. Moreover, the fullerene derivatives' oxidative activity and fluorescence quenching, which could be one of the reasons for the inconsistency among reported anti-HIV-1 mechanisms, are discussed herein.
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29
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Ingram Z, Fischer DK, Ambrose Z. Disassembling the Nature of Capsid: Biochemical, Genetic, and Imaging Approaches to Assess HIV-1 Capsid Functions. Viruses 2021; 13:v13112237. [PMID: 34835043 PMCID: PMC8618418 DOI: 10.3390/v13112237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/31/2021] [Accepted: 11/01/2021] [Indexed: 12/20/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) capsid and its disassembly, or capsid uncoating, has remained an active area of study over the past several decades. Our understanding of the HIV-1 capsid as solely a protective shell has since shifted with discoveries linking it to other complex replication events. The interplay of the HIV-1 capsid with reverse transcription, nuclear import, and integration has led to an expansion of knowledge of capsid functionality. Coincident with advances in microscopy, cell, and biochemistry assays, several models of capsid disassembly have been proposed, in which it occurs in either the cytoplasmic, nuclear envelope, or nuclear regions of the cell. Here, we discuss how the understanding of the HIV-1 capsid has evolved and the key methods that made these discoveries possible.
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Affiliation(s)
- Zachary Ingram
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA; (Z.I.); (D.K.F.)
- Pittsburgh Center for HIV Protein Interactions, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Douglas K. Fischer
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA; (Z.I.); (D.K.F.)
- Pittsburgh Center for HIV Protein Interactions, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Zandrea Ambrose
- Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA; (Z.I.); (D.K.F.)
- Pittsburgh Center for HIV Protein Interactions, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Correspondence:
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Abstract
To infect nondividing cells, HIV-1 needs to cross the nuclear membrane. The importin transportin-SR2 (TRN-SR2 or transportin-3) has been proposed to mediate HIV-1 nuclear import, but the detailed mechanism remains unresolved. The direct interaction of TRN-SR2 with HIV-1 integrase (IN) has been proposed to drive HIV-1 nuclear import. Alternatively, TRN-SR2 may play an indirect role by mediating nuclear import of cleavage and polyadenylation specificity factor 6 (CPSF6). To unravel the role of TRN-SR2, we designed CRISPR/Cas9 guide RNAs targeting different exons of TNPO3. Although this approach failed to generate full knockouts, monoallelic knockout clones were generated with indel mutations. HIV-1 replication was hampered in those clones at the level of HIV-1 nuclear import without an effect on the cellular distribution of the TRN-SR2 cargoes CPSF6 or alternative splicing factor1/pre-mRNA splicing factor SF2 (ASF/SF2). Recombinant ΔV105 TRN-SR2 expressed in clone 15.15 was 2-fold impaired for interaction with HIV-1 IN and classified as an interaction mutant. Our data support a model whereby TRN-SR2 acts as a cofactor of HIV-1 nuclear import without compromising the nuclear import of cellular cargoes. CRISPR/Cas9-induced mutagenesis can be used as a method to generate interface mutants to characterize host factors of human pathogens. IMPORTANCE Combination antiretroviral therapy (cART) effectively controls HIV-1 by reducing viral loads, but it does not cure the infection. Lifelong treatment with cART is a prerequisite for sustained viral suppression. The rapid emergence of drug-resistant viral strains drives the necessity to discover new therapeutic targets. The nuclear import of HIV-1 is crucial in the HIV-1 replication cycle, but the detailed mechanism remains incompletely understood. This study provides evidence that TRN-SR2 directly mediates HIV-1 nuclear import via the interaction with HIV-1 integrase. The interaction between those proteins is therefore a promising target toward a rational drug design which could lead to new therapeutic strategies due to the bottleneck nature of HIV-1 nuclear import.
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Dynactin 1 negatively regulates HIV-1 infection by sequestering the host cofactor CLIP170. Proc Natl Acad Sci U S A 2021; 118:2102884118. [PMID: 34686593 DOI: 10.1073/pnas.2102884118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2021] [Indexed: 11/18/2022] Open
Abstract
Many viruses directly engage and require the dynein-dynactin motor-adaptor complex in order to transport along microtubules (MTs) to the nucleus and initiate infection. HIV type 1 (HIV-1) exploits dynein, the dynein adaptor BICD2, and core dynactin subunits but unlike several other viruses, does not require dynactin-1 (DCTN1). The underlying reason for HIV-1's variant dynein engagement strategy and independence from DCTN1 remains unknown. Here, we reveal that DCTN1 actually inhibits early HIV-1 infection by interfering with the ability of viral cores to interact with critical host cofactors. Specifically, DCTN1 competes for binding to HIV-1 particles with cytoplasmic linker protein 170 (CLIP170), one of several MT plus-end tracking proteins (+TIPs) that regulate the stability of viral cores after entry into the cell. Outside of its function as a dynactin subunit, DCTN1 also functions as a +TIP that we find sequesters CLIP170 from incoming particles. Deletion of the Zinc knuckle (Zn) domain in CLIP170 that mediates its interactions with several proteins, including DCTN1, increased CLIP170 binding to virus particles but failed to promote infection, further suggesting that DCTN1 blocks a critical proviral function of CLIP170 mediated by its Zn domain. Our findings suggest that the unique manner in which HIV-1 binds and exploits +TIPs to regulate particle stability leaves them vulnerable to the negative effects of DCTN1 on +TIP availability and function, which may in turn have driven HIV-1 to evolve away from DCTN1 in favor of BICD2-based engagement of dynein during early infection.
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Abstract
Complement-opsonized HIV-1 triggers efficient antiviral type I interferon (IFN) responses in dendritic cells (DCs), which play an important role in protective responses at the earliest stages in retroviral infection. In contrast, HIV-1 suppresses or escapes sensing by STING- and MAVS-associated sensors. Here, we identified a complement receptor-mediated sensing pathway, where DCs are activated in CCR5/RLR (RIG-I/MDA5)/MAVS/TBK1-dependent fashion. Increased fusion of complement-opsonized HIV-1 via complement receptor 4 and CCR5 leads to increased incoming HIV-1 RNA in the cytoplasm, sensed by a nonredundant cooperative effect of RIG-I and MDA5. Moreover, complement-opsonized HIV-1 down-modulated the MAVS-suppressive Raf-1/PLK1 pathway, thereby opening the antiviral recognition pathway via MAVS. This in turn was followed by MAVS aggregation and subsequent TBK1/IRF3/NF-κB activation in DCs exposed to complement- but not non-opsonized HIV-1. Our data strongly suggest that complement is important in the induction of efficient antiviral immune responses by preventing HIV-1 suppressive mechanisms as well as inducing specific cytosolic sensors.
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33
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Saito A, Yamashita M. HIV-1 capsid variability: viral exploitation and evasion of capsid-binding molecules. Retrovirology 2021; 18:32. [PMID: 34702294 PMCID: PMC8549334 DOI: 10.1186/s12977-021-00577-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/13/2021] [Indexed: 11/17/2022] Open
Abstract
The HIV-1 capsid, a conical shell encasing viral nucleoprotein complexes, is involved in multiple post-entry processes during viral replication. Many host factors can directly bind to the HIV-1 capsid protein (CA) and either promote or prevent HIV-1 infection. The viral capsid is currently being explored as a novel target for therapeutic interventions. In the past few decades, significant progress has been made in our understanding of the capsid–host interactions and mechanisms of action of capsid-targeting antivirals. At the same time, a large number of different viral capsids, which derive from many HIV-1 mutants, naturally occurring variants, or diverse lentiviruses, have been characterized for their interactions with capsid-binding molecules in great detail utilizing various experimental techniques. This review provides an overview of how sequence variation in CA influences phenotypic properties of HIV-1. We will focus on sequence differences that alter capsid–host interactions and give a brief account of drug resistant mutations in CA and their mutational effects on viral phenotypes. Increased knowledge of the sequence-function relationship of CA helps us deepen our understanding of the adaptive potential of the viral capsid.
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Affiliation(s)
- Akatsuki Saito
- Department of Veterinary Medicine, Faculty of Agriculture, University of Miyazaki, Miyazaki, Miyazaki, Japan.,Center for Animal Disease Control, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Masahiro Yamashita
- Aaron Diamond AIDS Research Center, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.
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34
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Chia T, Nakamura T, Amano M, Takamune N, Matsuoka M, Nakata H. A Small Molecule, ACAi-028, with Anti-HIV-1 Activity Targets a Novel Hydrophobic Pocket on HIV-1 Capsid. Antimicrob Agents Chemother 2021; 65:e0103921. [PMID: 34228546 PMCID: PMC8448090 DOI: 10.1128/aac.01039-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 06/28/2021] [Indexed: 12/21/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) capsid (CA) is an essential viral component of HIV-1 infection and an attractive therapeutic target for antivirals. Here, we report that a small molecule, ACAi-028, inhibits HIV-1 replication by targeting a hydrophobic pocket in the N-terminal domain of CA (CA-NTD). ACAi-028 is 1 of more than 40 candidate anti-HIV-1 compounds identified by in silico screening and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Our binding model showed that ACAi-028 interacts with the Q13, S16, and T19 amino acid residues, via hydrogen bonds, in the targeting pocket of CA-NTD. Using recombinant fusion methods, TZM-bl, time-of-addition, and colorimetric reverse transcriptase (RT) assays, the compound was found to exert anti-HIV-1 activity in the early stage between reverse transcription and proviral DNA integration, without any effect on RT activity in vitro, suggesting that this compound may affect HIV-1 core disassembly (uncoating) as well as a CA inhibitor, PF74. Moreover, electrospray ionization mass spectrometry (ESI-MS) also showed that the compound binds directly and noncovalently to the CA monomer. CA multimerization and thermal stability assays showed that ACAi-028 decreased CA multimerization and thermal stability via S16 or T19 residues. These results indicate that ACAi-028 is a new CA inhibitor by binding to the novel hydrophobic pocket in CA-NTD. This study demonstrates that a compound, ACAi-028, targeting the hydrophobic pocket should be a promising anti-HIV-1 inhibitor.
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Affiliation(s)
- Travis Chia
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Tomofumi Nakamura
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Masayuki Amano
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Nobutoki Takamune
- Kumamoto Innovative Development Organization, Kumamoto University, Kumamoto, Japan
| | - Masao Matsuoka
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Hirotomo Nakata
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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35
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Dubey AR, Jagtap YA, Kumar P, Patwa SM, Kinger S, Kumar A, Singh S, Prasad A, Jana NR, Mishra A. Biochemical strategies of E3 ubiquitin ligases target viruses in critical diseases. J Cell Biochem 2021; 123:161-182. [PMID: 34520596 DOI: 10.1002/jcb.30143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/23/2021] [Accepted: 08/24/2021] [Indexed: 12/15/2022]
Abstract
Viruses are known to cause various diseases in human and also infect other species such as animal plants, fungi, and bacteria. Replication of viruses depends upon their interaction with hosts. Human cells are prone to such unwanted viral infections. Disintegration and reconstitution require host machinery and various macromolecules like DNA, RNA, and proteins are invaded by viral particles. E3 ubiquitin ligases are known for their specific function, that is, recognition of their respective substrates for intracellular degradation. Still, we do not understand how ubiquitin proteasome system-based enzymes E3 ubiquitin ligases do their functional interaction with different viruses. Whether E3 ubiquitin ligases help in the elimination of viral components or viruses utilize their molecular capabilities in their intracellular propagation is not clear. The first time our current article comprehends fundamental concepts and new insights on the different viruses and their interaction with various E3 Ubiquitin Ligases. In this review, we highlight the molecular pathomechanism of viruses linked with E3 Ubiquitin Ligases dependent mechanisms. An enhanced understanding of E3 Ubiquitin Ligase-mediated removal of viral proteins may open new therapeutic strategies against viral infections.
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Affiliation(s)
- Ankur R Dubey
- Department of Bioscience and Bioengineering, Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, India
| | - Yuvraj A Jagtap
- Department of Bioscience and Bioengineering, Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, India
| | - Prashant Kumar
- Department of Bioscience and Bioengineering, Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, India
| | - Som M Patwa
- Department of Bioscience and Bioengineering, Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, India
| | - Sumit Kinger
- Department of Bioscience and Bioengineering, Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, India
| | - Amit Kumar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Sarika Singh
- Department of Neuroscience and Ageing Biology, Division of Toxicology and Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Amit Prasad
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | - Nihar R Jana
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Amit Mishra
- Department of Bioscience and Bioengineering, Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan, India
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36
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Guedán A, Donaldson CD, Caroe ER, Cosnefroy O, Taylor IA, Bishop KN. HIV-1 requires capsid remodelling at the nuclear pore for nuclear entry and integration. PLoS Pathog 2021; 17:e1009484. [PMID: 34543344 PMCID: PMC8483370 DOI: 10.1371/journal.ppat.1009484] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 09/30/2021] [Accepted: 09/04/2021] [Indexed: 11/18/2022] Open
Abstract
The capsid (CA) lattice of the HIV-1 core plays a key role during infection. From the moment the core is released into the cytoplasm, it interacts with a range of cellular factors that, ultimately, direct the pre-integration complex to the integration site. For integration to occur, the CA lattice must disassemble. Early uncoating or a failure to do so has detrimental effects on virus infectivity, indicating that an optimal stability of the viral core is crucial for infection. Here, we introduced cysteine residues into HIV-1 CA in order to induce disulphide bond formation and engineer hyper-stable mutants that are slower or unable to uncoat, and then followed their replication. From a panel of mutants, we identified three with increased capsid stability in cells and found that, whilst the M68C/E212C mutant had a 5-fold reduction in reverse transcription, two mutants, A14C/E45C and E180C, were able to reverse transcribe to approximately WT levels in cycling cells. Moreover, these mutants only had a 5-fold reduction in 2-LTR circle production, suggesting that not only could reverse transcription complete in hyper-stable cores, but that the nascent viral cDNA could enter the nuclear compartment. Furthermore, we observed A14C/E45C mutant capsid in nuclear and chromatin-associated fractions implying that the hyper-stable cores themselves entered the nucleus. Immunofluorescence studies revealed that although the A14C/E45C mutant capsid reached the nuclear pore with the same kinetics as wild type capsid, it was then retained at the pore in association with Nup153. Crucially, infection with the hyper-stable mutants did not promote CPSF6 re-localisation to nuclear speckles, despite the mutant capsids being competent for CPSF6 binding. These observations suggest that hyper-stable cores are not able to uncoat, or remodel, enough to pass through or dissociate from the nuclear pore and integrate successfully. This, is turn, highlights the importance of capsid lattice flexibility for nuclear entry. In conclusion, we hypothesise that during a productive infection, a capsid remodelling step takes place at the nuclear pore that releases the core complex from Nup153, and relays it to CPSF6, which then localises it to chromatin ready for integration.
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Affiliation(s)
- Anabel Guedán
- Retroviral Replication Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Callum D. Donaldson
- Retroviral Replication Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Eve R. Caroe
- Retroviral Replication Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ophélie Cosnefroy
- Retroviral Replication Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ian A. Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Kate N. Bishop
- Retroviral Replication Laboratory, The Francis Crick Institute, London, United Kingdom
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37
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Abstract
Here, we used a fluorescent protein that is free in solution and is trapped in nuclear HIV-1 capsids to demonstrate that the capsids retain integrity and prevent mixing of macromolecules within the viral core and the cellular environment until just before integration. We also found that capsid integrity is maintained until just minutes before disassembly in the nucleus, revealing that uncoating proceeds rapidly after integrity loss. These valuable insights into the early stage of HIV-1 replication indicate that intact HIV-1 capsids are imported through nuclear pores, that reverse transcription is mostly completed within intact capsids, and that preintegration complex-host interactions facilitating integration and target site selection must occur within a short time frame between capsid disassembly and integration. We recently reported that HIV-1 cores that retained >94% of their capsid (CA) protein entered the nucleus and disassembled (uncoated) near their integration site <1.5 h before integration. However, whether the nuclear capsids lost their integrity by rupturing or a small loss of CA before capsid disassembly was unclear. Here, we utilized a previously reported vector in which green fluorescent protein is inserted in HIV-1 Gag (iGFP); proteolytic processing efficiently releases GFP, some of which remains trapped inside capsids and serves as a fluid phase content marker that is released when the capsids lose their integrity. We found that nuclear capsids retained their integrity until shortly before integration and lost their GFP content marker ∼1 to 3 min before loss of capsid-associated mRuby-tagged cleavage and polyadenylation specificity factor 6 (mRuby-CPSF6). In contrast, loss of GFP fused to CA and mRuby-CPSF6 occurred simultaneously, indicating that viral cores retain their integrity until just minutes before uncoating. Our results indicate that HIV-1 evolved to retain its capsid integrity and maintain a separation between macromolecules in the viral core and the nuclear environment until uncoating occurs just before integration. These observations imply that intact HIV-1 capsids are imported through nuclear pores; that reverse transcription occurs in an intact capsid; and that interactions between the preintegration complex and LEDGF/p75, and possibly other host factors that facilitate integration, must occur during the short time period between loss of capsid integrity and integration.
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38
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Ingram Z, Matheney H, Wise E, Weatherford C, Hulme AE. Overlap Intensity: An ImageJ Macro for Analyzing the HIV-1 In Situ Uncoating Assay. Viruses 2021; 13:v13081604. [PMID: 34452469 PMCID: PMC8402712 DOI: 10.3390/v13081604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Capsid uncoating is at the crossroads of early steps in HIV-1 replication. In recent years, the development of novel assays has expanded how HIV-1 uncoating can be studied. In the in situ uncoating assay, dual fluorescently labelled virus allows for the identification of fused viral cores. Antibody staining then detects the amount of capsid associated with each viral core at different times post-infection. Following fixed cell imaging, manual counting can be used to assess the fusion state and capsid signal for each viral core, but this method can introduce bias with increased time of analysis. To address these limitations, we developed the Overlap Intensity macro in ImageJ. This macro automates the detection of viral cores and quantification of overlapping fusion and capsid signals. We demonstrated the high accuracy of the macro by comparing core detection to manual methods. Analysis of an in situ uncoating assay further verified the macro by detecting progressive uncoating as expected. Therefore, this macro improves the accessibility of the in situ uncoating assay by replacing time-consuming manual methods or the need for expensive data analysis software. Beyond the described assay, the Overlap Intensity macro includes adjustable settings for use in other methods requiring quantification of overlapping fluorescent signals.
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39
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Guedán A, Caroe ER, Barr GCR, Bishop KN. The Role of Capsid in HIV-1 Nuclear Entry. Viruses 2021; 13:1425. [PMID: 34452291 PMCID: PMC8402913 DOI: 10.3390/v13081425] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/16/2021] [Accepted: 07/17/2021] [Indexed: 12/19/2022] Open
Abstract
HIV-1 can infect non-dividing cells. The nuclear envelope therefore represents a barrier that HIV-1 must traverse in order to gain access to the host cell chromatin for integration. Hence, nuclear entry is a critical step in the early stages of HIV-1 replication. Following membrane fusion, the viral capsid (CA) lattice, which forms the outer face of the retroviral core, makes numerous interactions with cellular proteins that orchestrate the progress of HIV-1 through the replication cycle. The ability of CA to interact with nuclear pore proteins and other host factors around the nuclear pore determines whether nuclear entry occurs. Uncoating, the process by which the CA lattice opens and/or disassembles, is another critical step that must occur prior to integration. Both early and delayed uncoating have detrimental effects on viral infectivity. How uncoating relates to nuclear entry is currently hotly debated. Recent technological advances have led to intense discussions about the timing, location, and requirements for uncoating and have prompted the field to consider alternative uncoating scenarios that presently focus on uncoating at the nuclear pore and within the nuclear compartment. This review describes recent advances in the study of HIV-1 nuclear entry, outlines the interactions of the retroviral CA protein, and discusses the challenges of investigating HIV-1 uncoating.
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Affiliation(s)
| | | | | | - Kate N. Bishop
- Retroviral Replication Laboratory, The Francis Crick Institute, London NW1 1AT, UK; (A.G.); (E.R.C.); (G.C.R.B.)
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Naghavi MH. HIV-1 capsid exploitation of the host microtubule cytoskeleton during early infection. Retrovirology 2021; 18:19. [PMID: 34229718 PMCID: PMC8259435 DOI: 10.1186/s12977-021-00563-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/29/2021] [Indexed: 01/07/2023] Open
Abstract
Microtubules (MTs) form a filamentous array that provide both structural support and a coordinated system for the movement and organization of macromolecular cargos within the cell. As such, they play a critical role in regulating a wide range of cellular processes, from cell shape and motility to cell polarization and division. The array is radial with filament minus-ends anchored at perinuclear MT-organizing centers and filament plus-ends continuously growing and shrinking to explore and adapt to the intracellular environment. In response to environmental cues, a small subset of these highly dynamic MTs can become stabilized, acquire post-translational modifications and act as specialized tracks for cargo trafficking. MT dynamics and stability are regulated by a subset of highly specialized MT plus-end tracking proteins, known as +TIPs. Central to this is the end-binding (EB) family of proteins which specifically recognize and track growing MT plus-ends to both regulate MT polymerization directly and to mediate the accumulation of a diverse array of other +TIPs at MT ends. Moreover, interaction of EB1 and +TIPs with actin-MT cross-linking factors coordinate changes in actin and MT dynamics at the cell periphery, as well as during the transition of cargos from one network to the other. The inherent structural polarity of MTs is sensed by specialized motor proteins. In general, dynein directs trafficking of cargos towards the minus-end while most kinesins direct movement toward the plus-end. As a pathogenic cargo, HIV-1 uses the actin cytoskeleton for short-range transport most frequently at the cell periphery during entry before transiting to MTs for long-range transport to reach the nucleus. While the fundamental importance of MT networks to HIV-1 replication has long been known, recent work has begun to reveal the underlying mechanistic details by which HIV-1 engages MTs after entry into the cell. This includes mimicry of EB1 by capsid (CA) and adaptor-mediated engagement of dynein and kinesin motors to elegantly coordinate early steps in infection that include MT stabilization, uncoating (conical CA disassembly) and virus transport toward the nucleus. This review discusses recent advances in our understanding of how MT regulators and their associated motors are exploited by incoming HIV-1 capsid during early stages of infection.
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Affiliation(s)
- Mojgan H Naghavi
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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Tabasi M, Nombela I, Janssens J, Lahousse AP, Christ F, Debyser Z. Role of Transportin-SR2 in HIV-1 Nuclear Import. Viruses 2021; 13:829. [PMID: 34064404 PMCID: PMC8147801 DOI: 10.3390/v13050829] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/29/2021] [Accepted: 05/02/2021] [Indexed: 12/14/2022] Open
Abstract
The HIV replication cycle depends on the interaction of viral proteins with proteins of the host. Unraveling host-pathogen interactions during the infection is of great importance for understanding the pathogenesis and the development of antiviral therapies. To date HIV uncoating and nuclear import are the most debated steps of the HIV-1 replication cycle. Despite numerous studies during past decades, there is still much controversy with respect to the identity and the role of viral and host factors involved in these processes. In this review, we provide a comprehensive overview on the role of transportin-SR2 as a host cell factor during active nuclear transport.
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Affiliation(s)
| | | | | | | | | | - Zeger Debyser
- Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium; (M.T.); (I.N.); (J.J.); (A.P.L.); (F.C.)
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Müller TG, Zila V, Peters K, Schifferdecker S, Stanic M, Lucic B, Laketa V, Lusic M, Müller B, Kräusslich HG. HIV-1 uncoating by release of viral cDNA from capsid-like structures in the nucleus of infected cells. eLife 2021; 10:64776. [PMID: 33904396 PMCID: PMC8169111 DOI: 10.7554/elife.64776] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/21/2021] [Indexed: 12/11/2022] Open
Abstract
HIV-1 replication commences inside the cone-shaped viral capsid, but timing, localization, and mechanism of uncoating are under debate. We adapted a strategy to visualize individual reverse-transcribed HIV-1 cDNA molecules and their association with viral and cellular proteins using fluorescence and correlative-light-and-electron-microscopy (CLEM). We specifically detected HIV-1 cDNA inside nuclei, but not in the cytoplasm. Nuclear cDNA initially co-localized with a fluorescent integrase fusion (IN-FP) and the viral CA (capsid) protein, but cDNA-punctae separated from IN-FP/CA over time. This phenotype was conserved in primary HIV-1 target cells, with nuclear HIV-1 complexes exhibiting strong CA-signals in all cell types. CLEM revealed cone-shaped HIV-1 capsid-like structures and apparently broken capsid-remnants at the position of IN-FP signals and elongated chromatin-like structures in the position of viral cDNA punctae lacking IN-FP. Our data argue for nuclear uncoating by physical disruption rather than cooperative disassembly of the CA-lattice, followed by physical separation from the pre-integration complex.
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Affiliation(s)
- Thorsten G Müller
- Department of Infectious Diseases Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Vojtech Zila
- Department of Infectious Diseases Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Kyra Peters
- Department of Infectious Diseases Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Sandra Schifferdecker
- Department of Infectious Diseases Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Mia Stanic
- Department of Infectious Diseases Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Bojana Lucic
- Department of Infectious Diseases Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Vibor Laketa
- Department of Infectious Diseases Virology, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Infection Research, partner site Heidelberg, Heidelberg, Germany
| | - Marina Lusic
- Department of Infectious Diseases Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Infection Research, partner site Heidelberg, Heidelberg, Germany
| | - Barbara Müller
- Department of Infectious Diseases Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases Virology, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Infection Research, partner site Heidelberg, Heidelberg, Germany
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Toccafondi E, Lener D, Negroni M. HIV-1 Capsid Core: A Bullet to the Heart of the Target Cell. Front Microbiol 2021; 12:652486. [PMID: 33868211 PMCID: PMC8046902 DOI: 10.3389/fmicb.2021.652486] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/15/2021] [Indexed: 12/21/2022] Open
Abstract
The first step of the intracellular phase of retroviral infection is the release of the viral capsid core in the cytoplasm. This structure contains the viral genetic material that will be reverse transcribed and integrated into the genome of infected cells. Up to recent times, the role of the capsid core was considered essentially to protect this genetic material during the earlier phases of this process. However, increasing evidence demonstrates that the permanence inside the cell of the capsid as an intact, or almost intact, structure is longer than thought. This suggests its involvement in more aspects of the infectious cycle than previously foreseen, particularly in the steps of viral genomic material translocation into the nucleus and in the phases preceding integration. During the trip across the infected cell, many host factors are brought to interact with the capsid, some possessing antiviral properties, others, serving as viral cofactors. All these interactions rely on the properties of the unique component of the capsid core, the capsid protein CA. Likely, the drawback of ensuring these multiple functions is the extreme genetic fragility that has been shown to characterize this protein. Here, we recapitulate the busy agenda of an HIV-1 capsid in the infectious process, in particular in the light of the most recent findings.
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Affiliation(s)
| | - Daniela Lener
- CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Université de Strasbourg, Strasbourg, France
| | - Matteo Negroni
- CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Université de Strasbourg, Strasbourg, France
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Zhuang S, Torbett BE. Interactions of HIV-1 Capsid with Host Factors and Their Implications for Developing Novel Therapeutics. Viruses 2021; 13:417. [PMID: 33807824 PMCID: PMC8001122 DOI: 10.3390/v13030417] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/21/2021] [Accepted: 02/25/2021] [Indexed: 12/11/2022] Open
Abstract
The Human Immunodeficiency Virus type 1 (HIV-1) virion contains a conical shell, termed capsid, encasing the viral RNA genome. After cellular entry of the virion, the capsid is released and ensures the protection and delivery of the HIV-1 genome to the host nucleus for integration. The capsid relies on many virus-host factor interactions which are regulated spatiotemporally throughout the course of infection. In this paper, we will review the current understanding of the highly dynamic HIV-1 capsid-host interplay during the early stages of viral replication, namely intracellular capsid trafficking after viral fusion, nuclear import, uncoating, and integration of the viral genome into host chromatin. Conventional anti-retroviral therapies primarily target HIV-1 enzymes. Insights of capsid structure have resulted in a first-in-class, long-acting capsid-targeting inhibitor, GS-6207 (Lenacapavir). This inhibitor binds at the interface between capsid protein subunits, a site known to bind host factors, interferes with capsid nuclear import, HIV particle assembly, and ordered assembly. Our review will highlight capsid structure, the host factors that interact with capsid, and high-throughput screening techniques, specifically genomic and proteomic approaches, that have been and can be used to identify host factors that interact with capsid. Better structural and mechanistic insights into the capsid-host factor interactions will significantly inform the understanding of HIV-1 pathogenesis and the development of capsid-centric antiretroviral therapeutics.
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Affiliation(s)
- Shentian Zhuang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA;
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA
| | - Bruce E. Torbett
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA;
- Center for Immunity and Immunotherapies, Seattle Children’s Research Institute, Seattle, WA 98101, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98105, USA
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A New Generation of Functional Tagged Proteins for HIV Fluorescence Imaging. Viruses 2021; 13:v13030386. [PMID: 33670986 PMCID: PMC7997544 DOI: 10.3390/v13030386] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 12/14/2022] Open
Abstract
During the last decade, there was a marked increase in the development of tools and techniques to study the molecular mechanisms of the HIV replication cycle by using fluorescence microscopy. Researchers often apply the fusion of tags and fluorophores to viral proteins, surrogate proteins, or dyes to follow individual virus particles while they progress throughout infection. The inclusion of such fusion motifs or surrogates frequently disrupts viral infectivity or results in a change of the wild-type phenotype. Here, we detail the construction and functional characterization of two new constructs where we fused fluorescent proteins to the N-terminus of HIV-1 Integrase. In the first, IN is recruited into assembling particles via a codon optimized Gag to complement other viral constructs, while the second is fused to a Gag-Pol expression vector fully capable of integration. Our data shows that N-terminal tagged IN is functional for integration by both recovery of integration of catalytically inactive IN and by the successful infectivity of viruses carrying only labeled IN. These tools will be important to study the individual behavior of viral particles and associate such behavior to infectivity.
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Zila V, Margiotta E, Turoňová B, Müller TG, Zimmerli CE, Mattei S, Allegretti M, Börner K, Rada J, Müller B, Lusic M, Kräusslich HG, Beck M. Cone-shaped HIV-1 capsids are transported through intact nuclear pores. Cell 2021; 184:1032-1046.e18. [PMID: 33571428 PMCID: PMC7895898 DOI: 10.1016/j.cell.2021.01.025] [Citation(s) in RCA: 158] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/20/2020] [Accepted: 01/19/2021] [Indexed: 12/14/2022]
Abstract
Human immunodeficiency virus (HIV-1) remains a major health threat. Viral capsid uncoating and nuclear import of the viral genome are critical for productive infection. The size of the HIV-1 capsid is generally believed to exceed the diameter of the nuclear pore complex (NPC), indicating that capsid uncoating has to occur prior to nuclear import. Here, we combined correlative light and electron microscopy with subtomogram averaging to capture the structural status of reverse transcription-competent HIV-1 complexes in infected T cells. We demonstrated that the diameter of the NPC in cellulo is sufficient for the import of apparently intact, cone-shaped capsids. Subsequent to nuclear import, we detected disrupted and empty capsid fragments, indicating that uncoating of the replication complex occurs by breaking the capsid open, and not by disassembly into individual subunits. Our data directly visualize a key step in HIV-1 replication and enhance our mechanistic understanding of the viral life cycle.
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Affiliation(s)
- Vojtech Zila
- Department of Infectious Diseases, Virology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Erica Margiotta
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany; Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Beata Turoňová
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Thorsten G Müller
- Department of Infectious Diseases, Virology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Christian E Zimmerli
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Simone Mattei
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany; Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8092 Zurich, Switzerland; European Molecular Biology Laboratory, Imaging Center, 69117 Heidelberg, Germany
| | - Matteo Allegretti
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Kathleen Börner
- Department of Infectious Diseases, Virology, University of Heidelberg, 69120 Heidelberg, Germany; German Center for Infection Research, partner site Heidelberg, 69120 Heidelberg, Germany
| | - Jona Rada
- Department of Infectious Diseases, Virology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Barbara Müller
- Department of Infectious Diseases, Virology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Marina Lusic
- Department of Infectious Diseases, Virology, University of Heidelberg, 69120 Heidelberg, Germany; German Center for Infection Research, partner site Heidelberg, 69120 Heidelberg, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, University of Heidelberg, 69120 Heidelberg, Germany; German Center for Infection Research, partner site Heidelberg, 69120 Heidelberg, Germany.
| | - Martin Beck
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany; Max Planck Institute of Biophysics, Department of Molecular Sociology, 60438 Frankfurt, Germany.
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Wilbourne M, Zhang P. Visualizing HIV-1 Capsid and Its Interactions with Antivirals and Host Factors. Viruses 2021; 13:246. [PMID: 33557422 PMCID: PMC7914784 DOI: 10.3390/v13020246] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 02/03/2023] Open
Abstract
Understanding of the construction and function of the HIV capsid has advanced considerably in the last decade. This is due in large part to the development of more sophisticated structural techniques, particularly cryo-electron microscopy (cryoEM) and cryo-electron tomography (cryoET). The capsid is known to be a pleomorphic fullerene cone comprised of capsid protein monomers arranged into 200-250 hexamers and 12 pentamers. The latter of these induce high curvature necessary to close the cone at both ends. CryoEM/cryoET, NMR, and X-ray crystallography have collectively described these interactions to atomic or near-atomic resolutions. Further, these techniques have helped to clarify the role the HIV capsid plays in several parts of the viral life cycle, from reverse transcription to nuclear entry and integration into the host chromosome. This includes visualizing the capsid bound to host factors. Multiple proteins have been shown to interact with the capsid. Cyclophilin A, nucleoporins, and CPSF6 promote viral infectivity, while MxB and Trim5α diminish the viral infectivity. Finally, structural insights into the intra- and intermolecular interactions that govern capsid function have enabled development of small molecules, peptides, and truncated proteins to disrupt or stabilize the capsid to inhibit HIV replication. The most promising of these, GS6207, is now in clinical trial.
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Affiliation(s)
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
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Imaging Viral Infection by Fluorescence Microscopy: Focus on HIV-1 Early Stage. Viruses 2021; 13:v13020213. [PMID: 33573241 PMCID: PMC7911428 DOI: 10.3390/v13020213] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 12/15/2022] Open
Abstract
During the last two decades, progresses in bioimaging and the development of various strategies to fluorescently label the viral components opened a wide range of possibilities to visualize the early phase of Human Immunodeficiency Virus 1 (HIV-1) life cycle directly in infected cells. After fusion of the viral envelope with the cell membrane, the viral core is released into the cytoplasm and the viral RNA (vRNA) is retro-transcribed into DNA by the reverse transcriptase. During this process, the RNA-based viral complex transforms into a pre-integration complex (PIC), composed of the viral genomic DNA (vDNA) coated with viral and host cellular proteins. The protective capsid shell disassembles during a process called uncoating. The viral genome is transported into the cell nucleus and integrates into the host cell chromatin. Unlike biochemical approaches that provide global data about the whole population of viral particles, imaging techniques enable following individual viruses on a single particle level. In this context, quantitative microscopy has brought original data shedding light on the dynamics of the viral entry into the host cell, the cytoplasmic transport, the nuclear import, and the selection of the integration site. In parallel, multi-color imaging studies have elucidated the mechanism of action of host cell factors implicated in HIV-1 viral cycle progression. In this review, we describe the labeling strategies used for HIV-1 fluorescence imaging and report on the main advancements that imaging studies have brought in the understanding of the infection mechanisms from the viral entry into the host cell until the provirus integration step.
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Structure, Function, and Interactions of the HIV-1 Capsid Protein. Life (Basel) 2021; 11:life11020100. [PMID: 33572761 PMCID: PMC7910843 DOI: 10.3390/life11020100] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 11/30/2022] Open
Abstract
The capsid (CA) protein of the human immunodeficiency virus type 1 (HIV-1) is an essential structural component of a virion and facilitates many crucial life cycle steps through interactions with host cell factors. Capsid shields the reverse transcription complex from restriction factors while it enables trafficking to the nucleus by hijacking various adaptor proteins, such as FEZ1 and BICD2. In addition, the capsid facilitates the import and localization of the viral complex in the nucleus through interaction with NUP153, NUP358, TNPO3, and CPSF-6. In the later stages of the HIV-1 life cycle, CA plays an essential role in the maturation step as a constituent of the Gag polyprotein. In the final phase of maturation, Gag is cleaved, and CA is released, allowing for the assembly of CA into a fullerene cone, known as the capsid core. The fullerene cone consists of ~250 CA hexamers and 12 CA pentamers and encloses the viral genome and other essential viral proteins for the next round of infection. As research continues to elucidate the role of CA in the HIV-1 life cycle and the importance of the capsid protein becomes more apparent, CA displays potential as a therapeutic target for the development of HIV-1 inhibitors.
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Menees TM. Saccharomyces cerevisiae RNA lariat debranching enzyme, Dbr1p, is required for completion of reverse transcription by the retrovirus-like element Ty1 and cleaves branched Ty1 RNAs. Mol Genet Genomics 2021; 296:409-422. [PMID: 33464395 DOI: 10.1007/s00438-020-01753-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/14/2020] [Indexed: 11/25/2022]
Abstract
RNA debranching enzymes are 2'-5' phosphodiesterases found in all eukaryotes. Their main role is cleavage of intron RNA lariat branch points, promoting RNA turnover via exonucleases. Consistent with this role, cells with reduced RNA debranching enzyme activity accumulate intron RNA lariats. The Saccharomyces cerevisiae RNA debranching enzyme Dbr1p is also a host factor for the yeast long terminal repeat (LTR) retrotransposon Ty1, a model for many aspects of retroviral replication. Fittingly, the human RNA debranching enzyme Dbr1 is a host factor for the human immunodeficiency virus, HIV-1. The yeast and human RNA debranching enzymes act at the reverse transcription stages for Ty1 and HIV-1, respectively. Although efficient production of full-length Ty1 cDNA requires Dbr1p, the findings reported here indicate that production of the earliest distinct cDNA product, minus strand strong stop DNA (-sssDNA), is equivalent in wild type and dbr1∆ mutant cells. Several branched Ty1 RNAs are shown to accumulate in dbr1∆ cells during retrotransposition. These data are consistent with creation of Ty1 RNA branches prior to Ty1 reverse transcription and their removal by Dbr1p to allow efficient extension of early cDNA products. The data support the possibility that RNA branch formation and cleavage play broadly shared, but unknown roles in retroviral and LTR retrotransposon reverse transcription.
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Affiliation(s)
- Thomas M Menees
- School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO, USA.
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