1
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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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2
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Gres AT, Kirby KA, McFadden WM, Du H, Liu D, Xu C, Bryer AJ, Perilla JR, Shi J, Aiken C, Fu X, Zhang P, Francis AC, Melikyan GB, Sarafianos SG. Multidisciplinary studies with mutated HIV-1 capsid proteins reveal structural mechanisms of lattice stabilization. Nat Commun 2023; 14:5614. [PMID: 37699872 PMCID: PMC10497533 DOI: 10.1038/s41467-023-41197-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 08/25/2023] [Indexed: 09/14/2023] Open
Abstract
HIV-1 capsid (CA) stability is important for viral replication. E45A and P38A mutations enhance and reduce core stability, thus impairing infectivity. Second-site mutations R132T and T216I rescue infectivity. Capsid lattice stability was studied by solving seven crystal structures (in native background), including P38A, P38A/T216I, E45A, E45A/R132T CA, using molecular dynamics simulations of lattices, cryo-electron microscopy of assemblies, time-resolved imaging of uncoating, biophysical and biochemical characterization of assembly and stability. We report pronounced and subtle, short- and long-range rearrangements: (1) A38 destabilized hexamers by loosening interactions between flanking CA protomers in P38A but not P38A/T216I structures. (2) Two E45A structures showed unexpected stabilizing CANTD-CANTD inter-hexamer interactions, variable R18-ring pore sizes, and flipped N-terminal β-hairpin. (3) Altered conformations of E45Aa α9-helices compared to WT, E45A/R132T, WTPF74, WTNup153, and WTCPSF6 decreased PF74, CPSF6, and Nup153 binding, and was reversed in E45A/R132T. (4) An environmentally sensitive electrostatic repulsion between E45 and D51 affected lattice stability, flexibility, ion and water permeabilities, electrostatics, and recognition of host factors.
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Affiliation(s)
- Anna T Gres
- C.S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Department of Chemistry, University of Missouri, Columbia, MO, USA
| | - Karen A Kirby
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - William M McFadden
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Haijuan Du
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Dandan Liu
- C.S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Department of Molecular Microbiology & Immunology, University of Missouri School of Medicine, Columbia, MO, USA
| | - Chaoyi Xu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA
| | - Alexander J Bryer
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA
| | - Juan R Perilla
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA
- Department of Physics & Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jiong Shi
- Department of Pathology, Immunology & Microbiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Christopher Aiken
- Department of Pathology, Immunology & Microbiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Xiaofeng Fu
- Department of Structural Biology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Peijun Zhang
- Department of Structural Biology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
- Division of Structural Biology, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Headington, Oxford, UK
- Electron Bio-Imaging Centre, Diamond Light Sources, Harwell Science and Innovation Campus, Didcot, UK
| | - Ashwanth C Francis
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, USA
| | - Gregory B Melikyan
- Children's Healthcare of Atlanta, Atlanta, GA, USA
- Division of Pediatric Infectious Diseases, Emory University School of Medicine, Atlanta, GA, USA
| | - Stefan G Sarafianos
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
- Children's Healthcare of Atlanta, Atlanta, GA, USA.
- Department of Molecular Microbiology & Immunology, University of Missouri School of Medicine, Columbia, MO, USA.
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3
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Huang Y, Zhang Y, Ni T. Towards in situ high-resolution imaging of viruses and macromolecular complexes using cryo-electron tomography. J Struct Biol 2023; 215:108000. [PMID: 37467823 DOI: 10.1016/j.jsb.2023.108000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 07/15/2023] [Accepted: 07/16/2023] [Indexed: 07/21/2023]
Abstract
Cryo-electron tomography and subtomogram averaging are rising and fast-evolving imaging techniques to study biological events, providing structural information at an unprecedented resolution while preserving spatial correlation in their native contexts. The latest technology and methodology development ranging from sample preparation to data collection and data processing, has enabled significant advancement in its applications to various biological systems. This review provides an overview of the current technology development enabling high-resolution structural study in situ, highlighting the use of a priori information of biological samples to assess the quality of subtomogram averaging pipeline. We exemplify the applications of this technique to understanding viruses and principles of macromolecule assembly using different biological systems, ranging from in vitro to in situ samples, which provide structural information at different resolutions and contexts.
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Affiliation(s)
- Yixin Huang
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Yu Zhang
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Tao Ni
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region.
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4
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Graham M, Zhang P. Cryo-electron tomography to study viral infection. Biochem Soc Trans 2023; 51:1701-1711. [PMID: 37560901 PMCID: PMC10578967 DOI: 10.1042/bst20230103] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/19/2023] [Accepted: 07/31/2023] [Indexed: 08/11/2023]
Abstract
Developments in cryo-electron microscopy (cryo-EM) have been interwoven with the study of viruses ever since its first applications to biological systems. Following the success of single particle cryo-EM in the last decade, cryo-electron tomography (cryo-ET) is now rapidly maturing as a technology and catalysing great advancement in structural virology as its application broadens. In this review, we provide an overview of the use of cryo-ET to study viral infection biology, discussing the key workflows and strategies used in the field. We highlight the vast body of studies performed on purified viruses and virus-like particles (VLPs), as well as discussing how cryo-ET can characterise host-virus interactions and membrane fusion events. We further discuss the importance of in situ cellular imaging in revealing previously unattainable details of infection and highlight the need for validation of high-resolution findings from purified ex situ systems. We give perspectives for future developments to achieve the full potential of cryo-ET to characterise the molecular processes of viral infection.
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Affiliation(s)
- Miles Graham
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, U.K
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, U.K
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K
- Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford OX3 7BN, U.K
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5
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Talledge N, Yang H, Shi K, Coray R, Yu G, Arndt WG, Meng S, Baxter GC, Mendonça LM, Castaño-Díez D, Aihara H, Mansky LM, Zhang W. HIV-2 Immature Particle Morphology Provides Insights into Gag Lattice Stability and Virus Maturation. J Mol Biol 2023; 435:168143. [PMID: 37150290 PMCID: PMC10524356 DOI: 10.1016/j.jmb.2023.168143] [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: 09/02/2022] [Revised: 05/01/2023] [Accepted: 05/01/2023] [Indexed: 05/09/2023]
Abstract
Retrovirus immature particle morphology consists of a membrane enclosed, pleomorphic, spherical and incomplete lattice of Gag hexamers. Previously, we demonstrated that human immunodeficiency virus type 2 (HIV-2) immature particles possess a distinct and extensive Gag lattice morphology. To better understand the nature of the continuously curved hexagonal Gag lattice, we have used the single particle cryo-electron microscopy method to determine the HIV-2 Gag lattice structure for immature virions. The reconstruction map at 5.5 Å resolution revealed a stable, wineglass-shaped Gag hexamer structure with structural features consistent with other lentiviral immature Gag lattice structures. Cryo-electron tomography provided evidence for nearly complete ordered Gag lattice structures in HIV-2 immature particles. We also solved a 1.98 Å resolution crystal structure of the carboxyl-terminal domain (CTD) of the HIV-2 capsid (CA) protein that identified a structured helix 12 supported via an interaction of helix 10 in the absence of the SP1 region of Gag. Residues at the helix 10-12 interface proved critical in maintaining HIV-2 particle release and infectivity. Taken together, our findings provide the first 3D organization of HIV-2 immature Gag lattice and important insights into both HIV Gag lattice stabilization and virus maturation.
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Affiliation(s)
- Nathaniel Talledge
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA. https://twitter.com/BioChemTalledge
| | - Huixin Yang
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Comparative Molecular Biosciences Graduate Program, University of Minnesota - Twin Cities, St. Paul, MN 55108, USA
| | - Ke Shi
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Raffaele Coray
- BioEM Lab, Biozentrum, University of Basel - Basel, Switzerland
| | - Guichuan Yu
- Minnesota Supercomputing Institute, Office of the Vice President for Research, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Characterization Facility, College of Sciences and Engineering, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - William G Arndt
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Biochemistry, Molecular Biology and Biophysics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Shuyu Meng
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Molecular Pharmacology and Therapeutics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Gloria C Baxter
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Molecular, Cellular, Developmental Biology, and Genetics Graduate Program, University of Minnesota - Twin Cities, USA
| | - Luiza M Mendonça
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Biochemistry, Molecular Biology and Biophysics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | | | - Hideki Aihara
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Biochemistry, Molecular Biology and Biophysics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Louis M Mansky
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Comparative Molecular Biosciences Graduate Program, University of Minnesota - Twin Cities, St. Paul, MN 55108, USA; Biochemistry, Molecular Biology and Biophysics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Molecular Pharmacology and Therapeutics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA.
| | - Wei Zhang
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Characterization Facility, College of Sciences and Engineering, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA.
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6
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Highland CM, Tan A, Ricaña CL, Briggs JAG, Dick RA. Structural insights into HIV-1 polyanion-dependent capsid lattice formation revealed by single particle cryo-EM. Proc Natl Acad Sci U S A 2023; 120:e2220545120. [PMID: 37094124 PMCID: PMC10160977 DOI: 10.1073/pnas.2220545120] [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: 12/02/2022] [Accepted: 03/12/2023] [Indexed: 04/26/2023] Open
Abstract
The HIV-1 capsid houses the viral genome and interacts extensively with host cell proteins throughout the viral life cycle. It is composed of capsid protein (CA), which assembles into a conical fullerene lattice composed of roughly 200 CA hexamers and 12 CA pentamers. Previous structural analyses of individual CA hexamers and pentamers have provided valuable insight into capsid structure and function, but detailed structural information about these assemblies in the broader context of the capsid lattice is lacking. In this study, we combined cryoelectron tomography and single particle analysis (SPA) cryoelectron microscopy to determine structures of continuous regions of the capsid lattice containing both hexamers and pentamers. We also developed a method of liposome scaffold-based in vitro lattice assembly ("lattice templating") that enabled us to directly study the lattice under a wider range of conditions than has previously been possible. Using this approach, we identified a critical role for inositol hexakisphosphate in pentamer formation and determined the structure of the CA lattice bound to the capsid-targeting antiretroviral drug GS-6207 (lenacapavir). Our work reveals key structural details of the mature HIV-1 CA lattice and establishes the combination of lattice templating and SPA as a robust strategy for studying retroviral capsid structure and capsid interactions with host proteins and antiviral compounds.
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Affiliation(s)
- Carolyn M. Highland
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
| | - Aaron Tan
- Structural Studies Division, Medical Research Council Laboratory of Molecular Biology, CambridgeCB2 0QH, UK
| | - Clifton L. Ricaña
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
| | - John A. G. Briggs
- Structural Studies Division, Medical Research Council Laboratory of Molecular Biology, CambridgeCB2 0QH, UK
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Munich82512, Germany
| | - Robert A. Dick
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
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7
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Lee E, Redzic JS, Saviola AJ, Li X, Ebmeier CC, Kutateladze T, Hansen KC, Zhao R, Ahn N, Sluchanko NN, Eisenmesser E. Molecular insight into the specific interactions of the SARS-Coronavirus-2 nucleocapsid with RNA and host protein. Protein Sci 2023; 32:e4603. [PMID: 36807437 PMCID: PMC10019451 DOI: 10.1002/pro.4603] [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: 12/20/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/23/2023]
Abstract
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) nucleocapsid protein is the most abundantly expressed viral protein during infection where it targets both RNA and host proteins. However, identifying how a single viral protein interacts with so many different targets remains a challenge, providing the impetus here for identifying the interaction sites through multiple methods. Through a combination of nuclear magnetic resonance (NMR), electron microscopy, and biochemical methods, we have characterized nucleocapsid interactions with RNA and with three host proteins, which include human cyclophilin-A, Pin1, and 14-3-3τ. Regarding RNA interactions, the nucleocapsid protein N-terminal folded domain preferentially interacts with smaller RNA fragments relative to the C-terminal region, suggesting an initial RNA engagement is largely dictated by this N-terminal region followed by weaker interactions to the C-terminal region. The nucleocapsid protein forms 10 nm ribonuclear complexes with larger RNA fragments that include 200 and 354 nucleic acids, revealing its potential diversity in sequestering different viral genomic regions during viral packaging. Regarding host protein interactions, while the nucleocapsid targets all three host proteins through its serine-arginine-rich region, unstructured termini of the nucleocapsid protein also engage host cyclophilin-A and host 14-3-3τ. Considering these host proteins play roles in innate immunity, the SARS-CoV-2 nucleocapsid protein may block the host response by competing interactions. Finally, phosphorylation of the nucleocapsid protein quenches an inherent dynamic exchange process within its serine-arginine-rich region. Our studies identify many of the diverse interactions that may be important for SARS-CoV-2 pathology during infection.
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Affiliation(s)
- Eunjeong Lee
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Jasmina S. Redzic
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Anthony J. Saviola
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Xueni Li
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | | | - Tatiana Kutateladze
- Department of PharmacologySchool of Medicine, University of Colorado DenverAuroraColoradoUSA
| | - Kirk Charles Hansen
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
| | - Natalie Ahn
- Department of BiochemistryUniversity of Colorado BoulderBoulderColoradoUSA
| | - Nikolai N. Sluchanko
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of SciencesMoscowRussia
| | - Elan Eisenmesser
- Department of Biochemistry and Molecular Genetics, School of MedicineUniversity of Colorado DenverAuroraColoradoUSA
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8
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Wu C, Xiong Y. Enrich and switch: IP6 and maturation of HIV-1 capsid. Nat Struct Mol Biol 2023; 30:239-241. [PMID: 36849641 PMCID: PMC10033439 DOI: 10.1038/s41594-023-00940-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Recent studies offer new insight on the mechanisms of IP6-mediated HIV-1 capsid assembly. The immature Gag lattice enables enrichment of IP6 into virions, aiding capsid maturation. Structures of capsid protein (CA) assemblies reveal motifs serving as switches modulating the conformations of CA pentamers/hexamers and affect co-factor accessibility.
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Affiliation(s)
- Chunxiang Wu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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9
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Gupta M, Pak AJ, Voth GA. Critical mechanistic features of HIV-1 viral capsid assembly. SCIENCE ADVANCES 2023; 9:eadd7434. [PMID: 36608139 PMCID: PMC9821859 DOI: 10.1126/sciadv.add7434 10.1126/sciadv.add7434] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 12/08/2022] [Indexed: 11/04/2023]
Abstract
The maturation of HIV-1 capsid protein (CA) into a cone-shaped lattice capsid is critical for viral infectivity. CA can self-assemble into a range of capsid morphologies made of ~175 to 250 hexamers and 12 pentamers. The cellular polyanion inositol hexakisphosphate (IP6) has recently been demonstrated to facilitate conical capsid formation by coordinating a ring of arginine residues within the central cavity of capsid hexamers and pentamers. However, the kinetic interplay of events during IP6 and CA coassembly is unclear. In this work, we use coarse-grained molecular dynamics simulations to elucidate the molecular mechanism of capsid formation, including the role played by IP6. We show that IP6, in small quantities at first, promotes curvature generation by trapping pentameric defects in the growing lattice and shifts assembly behavior toward kinetically favored outcomes. Our analysis also suggests that IP6 can stabilize metastable capsid intermediates and can induce structural pleomorphism in mature capsids.
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Affiliation(s)
- Manish Gupta
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, IL 60637, USA
| | | | - Gregory A. Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, IL 60637, USA
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10
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Gupta M, Pak AJ, Voth GA. Critical mechanistic features of HIV-1 viral capsid assembly. SCIENCE ADVANCES 2023; 9:eadd7434. [PMID: 36608139 PMCID: PMC9821859 DOI: 10.1126/sciadv.add7434+10.1126/sciadv.add7434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 12/08/2022] [Indexed: 01/21/2024]
Abstract
The maturation of HIV-1 capsid protein (CA) into a cone-shaped lattice capsid is critical for viral infectivity. CA can self-assemble into a range of capsid morphologies made of ~175 to 250 hexamers and 12 pentamers. The cellular polyanion inositol hexakisphosphate (IP6) has recently been demonstrated to facilitate conical capsid formation by coordinating a ring of arginine residues within the central cavity of capsid hexamers and pentamers. However, the kinetic interplay of events during IP6 and CA coassembly is unclear. In this work, we use coarse-grained molecular dynamics simulations to elucidate the molecular mechanism of capsid formation, including the role played by IP6. We show that IP6, in small quantities at first, promotes curvature generation by trapping pentameric defects in the growing lattice and shifts assembly behavior toward kinetically favored outcomes. Our analysis also suggests that IP6 can stabilize metastable capsid intermediates and can induce structural pleomorphism in mature capsids.
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Affiliation(s)
- Manish Gupta
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, IL 60637, USA
| | | | - Gregory A. Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, IL 60637, USA
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11
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Gupta M, Pak AJ, Voth GA. Critical mechanistic features of HIV-1 viral capsid assembly. SCIENCE ADVANCES 2023; 9:eadd7434. [PMID: 36608139 PMCID: PMC9821859 DOI: 10.1126/sciadv.add7434] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 12/08/2022] [Indexed: 05/29/2023]
Abstract
The maturation of HIV-1 capsid protein (CA) into a cone-shaped lattice capsid is critical for viral infectivity. CA can self-assemble into a range of capsid morphologies made of ~175 to 250 hexamers and 12 pentamers. The cellular polyanion inositol hexakisphosphate (IP6) has recently been demonstrated to facilitate conical capsid formation by coordinating a ring of arginine residues within the central cavity of capsid hexamers and pentamers. However, the kinetic interplay of events during IP6 and CA coassembly is unclear. In this work, we use coarse-grained molecular dynamics simulations to elucidate the molecular mechanism of capsid formation, including the role played by IP6. We show that IP6, in small quantities at first, promotes curvature generation by trapping pentameric defects in the growing lattice and shifts assembly behavior toward kinetically favored outcomes. Our analysis also suggests that IP6 can stabilize metastable capsid intermediates and can induce structural pleomorphism in mature capsids.
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12
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Ding D, Xu S, Zhang X, Jiang X, Cocklin S, Dick A, Zhan P, Liu X. The discovery and design of novel HIV-1 capsid modulators and future perspectives. Expert Opin Drug Discov 2023; 18:5-12. [PMID: 36480372 DOI: 10.1080/17460441.2023.2157401] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Although combination antiretroviral therapy (cART) has achieved significant success in treating HIV, the emergence of multidrug-resistant viruses and cumulative medication toxicity make it necessary to find new classes of antiretroviral agents with novel mechanisms of action. With high sequence conservation, the HIV-1 capsid (CA) protein has attracted attention as a prospective therapeutic target due to its crucial structural and regulatory functions in the HIV-1 replication cycle. AREA COVERED Herein, the authors provide a cutting-edge overview of current advances in the design and discovery of CA modulators, PF74, GS-6207 and their derivativeswhich targets a therapeutically attractive NTD-CTD interprotomer pocket within the hexameric configuration of HIV-1 CA. The discovery and development of these compounds, and derivatives thereof, have provided valuable information for the design of second-generation CA-targeting antivirals. EXPERT OPINION Despite some successes in designing and discovering HIV-1 CA modulators, more studies are required to decipher which chemical groups confer specific desirable properties. The future of CA-modulating compounds may lie in covalent inhibition and the creation of proteolysis-targeting chimeras (PROTACs). Moreover, biological interrogation of the process of CA uncoating, virus-host interactions, and studies on the lattice-binding restriction factors may improve our knowledge of HIV-1 CA and support the design of new antiviral agents.
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Affiliation(s)
- Dang Ding
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Shujing Xu
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Xujie Zhang
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Xiangyi Jiang
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Simon Cocklin
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Alexej Dick
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Peng Zhan
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
| | - Xinyong Liu
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, PR China
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13
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Han J, Kyu Lee M, Jang Y, Cho WJ, Kim M. Repurposing of cyclophilin A inhibitors as broad-spectrum antiviral agents. Drug Discov Today 2022; 27:1895-1912. [PMID: 35609743 PMCID: PMC9123807 DOI: 10.1016/j.drudis.2022.05.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/30/2022] [Accepted: 05/18/2022] [Indexed: 12/28/2022]
Abstract
Cyclophilin A (CypA) is linked to diverse human diseases including viral infections. With the worldwide emergence of severe acute respiratory coronavirus 2 (SARS-CoV-2), drug repurposing has been highlighted as a strategy with the potential to speed up antiviral development. Because CypA acts as a proviral component in hepatitis C virus, coronavirus and HIV, its inhibitors have been suggested as potential treatments for these infections. Here, we review the structure of cyclosporin A and sanglifehrin A analogs as well as synthetic micromolecules inhibiting CypA; and we discuss their broad-spectrum antiviral efficacy in the context of the virus lifecycle.
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Affiliation(s)
- Jinhe Han
- College of Pharmacy, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Myoung Kyu Lee
- Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea
| | - Yejin Jang
- Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea
| | - Won-Jea Cho
- College of Pharmacy, Chonnam National University, Gwangju, 61186, Republic of Korea.
| | - Meeheyin Kim
- Infectious Diseases Therapeutic Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea; Graduate School of New Drug Discovery and Development, Chungnam National University, Daejeon 34134, Republic of Korea.
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14
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Abstract
Biological structures with helical symmetries of distinct twist, rise, and axial symmetry are abundant and span a wide range of organisms and functions. Performing de novo helical indexing remains challenging because of the steep learning curve involved in Fourier space layer lines. The unknown amount of out-of-plane tilt and the existence of multiple conformations of the helices further complicate indexing. In this work, we introduce a real-space indexing method that leverages the prior knowledge of the tilt and in-plane angles of the helical filaments/tubes, robust ab initio 3D reconstruction capabilities in single particle cryo-EM to obtain asymmetric reconstructions, and automatic indexing of helical parameters directly from the asymmetric density maps. We validated this approach using data from multiple helical structures of distinct helical symmetries, diameters, flexibility, data qualities, and heterogeneous states. The fully automated tool we introduce for real space indexing, HI3D, uses the 2D lattice in the autocorrelation of the cylindrical projection of a 3D density map to identify the helical symmetry. HI3D can often successfully determine the helical parameters of a suboptimal 3D density map, including ab initio single particle asymmetric reconstructions and sub-tomogram averages, with intermediate evidence that can also help assess the map quality. Furthermore, this open-source HI3D is usable independently as a Web application that can be accessed free of installation. With these methods, de novo helical indexing will be significantly more accessible to researchers investigating structures of helical filaments/tubes using cryo-EM.
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Affiliation(s)
- Chen Sun
- grid.169077.e0000 0004 1937 2197Department of Biological Sciences, Markey Center for Structural Biology, Purdue University, West Lafayette, IN 47907 USA
| | - Brenda Gonzalez
- grid.169077.e0000 0004 1937 2197Department of Biological Sciences, Markey Center for Structural Biology, Purdue University, West Lafayette, IN 47907 USA
| | - Wen Jiang
- grid.169077.e0000 0004 1937 2197Department of Biological Sciences, Markey Center for Structural Biology, Purdue University, West Lafayette, IN 47907 USA
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15
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Balasubramaniam M, Davids BO, Bryer A, Xu C, Thapa S, Shi J, Aiken C, Pandhare J, Perilla JR, Dash C. HIV-1 mutants that escape the cytotoxic T-lymphocytes are defective in viral DNA integration. PNAS NEXUS 2022; 1:pgac064. [PMID: 35719891 PMCID: PMC9198661 DOI: 10.1093/pnasnexus/pgac064] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/17/2022] [Indexed: 12/02/2022]
Abstract
HIV-1 replication is durably controlled without antiretroviral therapy (ART) in certain infected individuals called elite controllers (ECs). These individuals express specific human leukocyte antigens (HLA) that tag HIV-infected cells for elimination by presenting viral epitopes to CD8+ cytotoxic T-lymphocytes (CTL). In HIV-infected individuals expressing HLA-B27, CTLs primarily target the viral capsid protein (CA)-derived KK10 epitope. While selection of CA mutation R264K helps HIV-1 escape this potent CTL response, the accompanying fitness cost severely diminishes virus infectivity. Interestingly, selection of a compensatory CA mutation S173A restores HIV-1 replication. However, the molecular mechanism(s) underlying HIV-1 escape from this ART-free virus control by CTLs is not fully understood. Here, we report that the R264K mutation-associated infectivity defect arises primarily from impaired HIV-1 DNA integration, which is restored by the S173A mutation. Unexpectedly, the integration defect of the R264K variant was also restored upon depletion of the host cyclophilin A. These findings reveal a nuclear crosstalk between CA and HIV-1 integration as well as identify a previously unknown role of cyclophilin A in viral DNA integration. Finally, our study identifies a novel immune escape mechanism of an HIV-1 variant escaping a CA-directed CTL response.
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Affiliation(s)
| | - Benem-Orom Davids
- The Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, TN - 37208, USA
| | - Alex Bryer
- Department of Chemistry, University of Delaware, Newark, DE - 19716, USA
| | - Chaoyi Xu
- Department of Chemistry, University of Delaware, Newark, DE - 19716, USA
| | - Santosh Thapa
- The Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, TN - 37208, USA
| | - Jiong Shi
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN - 37232, USA
| | - Christopher Aiken
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN - 37232, USA
| | - Jui Pandhare
- The Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, TN - 37208, USA
| | - Juan R Perilla
- Department of Chemistry, University of Delaware, Newark, DE - 19716, USA
| | - Chandravanu Dash
- The Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, TN - 37208, USA
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16
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Krebs AS, Mendonça LM, Zhang P. Structural Analysis of Retrovirus Assembly and Maturation. Viruses 2021; 14:54. [PMID: 35062258 PMCID: PMC8778513 DOI: 10.3390/v14010054] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/17/2021] [Accepted: 12/21/2021] [Indexed: 12/30/2022] Open
Abstract
Retroviruses have a very complex and tightly controlled life cycle which has been studied intensely for decades. After a virus enters the cell, it reverse-transcribes its genome, which is then integrated into the host genome, and subsequently all structural and regulatory proteins are transcribed and translated. The proteins, along with the viral genome, assemble into a new virion, which buds off the host cell and matures into a newly infectious virion. If any one of these steps are faulty, the virus cannot produce infectious viral progeny. Recent advances in structural and molecular techniques have made it possible to better understand this class of viruses, including details about how they regulate and coordinate the different steps of the virus life cycle. In this review we summarize the molecular analysis of the assembly and maturation steps of the life cycle by providing an overview on structural and biochemical studies to understand these processes. We also outline the differences between various retrovirus families with regards to these processes.
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Affiliation(s)
- Anna-Sophia Krebs
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.-S.K.); (L.M.M.)
| | - Luiza M. Mendonça
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.-S.K.); (L.M.M.)
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; (A.-S.K.); (L.M.M.)
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
- Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford OX3 7BN, UK
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17
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McFadden WM, Snyder AA, Kirby KA, Tedbury PR, Raj M, Wang Z, Sarafianos SG. Rotten to the core: antivirals targeting the HIV-1 capsid core. Retrovirology 2021; 18:41. [PMID: 34937567 PMCID: PMC8693499 DOI: 10.1186/s12977-021-00583-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/09/2021] [Indexed: 12/20/2022] Open
Abstract
The capsid core of HIV-1 is a large macromolecular assembly that surrounds the viral genome and is an essential component of the infectious virus. In addition to its multiple roles throughout the viral life cycle, the capsid interacts with multiple host factors. Owing to its indispensable nature, the HIV-1 capsid has been the target of numerous antiretrovirals, though most capsid-targeting molecules have not had clinical success until recently. Lenacapavir, a long-acting drug that targets the HIV-1 capsid, is currently undergoing phase 2/3 clinical trials, making it the most successful capsid inhibitor to-date. In this review, we detail the role of the HIV-1 capsid protein in the virus life cycle, categorize antiviral compounds based on their targeting of five sites within the HIV-1 capsid, and discuss their molecular interactions and mechanisms of action. The diverse range of inhibition mechanisms provides insight into possible new strategies for designing novel HIV-1 drugs and furthers our understanding of HIV-1 biology. ![]()
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Affiliation(s)
- William M McFadden
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Alexa A Snyder
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Karen A Kirby
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Philip R Tedbury
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA.,Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Monika Raj
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
| | - Zhengqiang Wang
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Stefan G Sarafianos
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA. .,Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA.
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18
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Ni T, Zhu Y, Yang Z, Xu C, Chaban Y, Nesterova T, Ning J, Böcking T, Parker MW, Monnie C, Ahn J, Perilla JR, Zhang P. Structure of native HIV-1 cores and their interactions with IP6 and CypA. SCIENCE ADVANCES 2021; 7:eabj5715. [PMID: 34797722 PMCID: PMC8604400 DOI: 10.1126/sciadv.abj5715] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 10/01/2021] [Indexed: 05/24/2023]
Abstract
The viral capsid plays essential roles in HIV replication and is a major platform engaging host factors. To overcome challenges in study native capsid structure, we used the perfringolysin O to perforate the membrane of HIV-1 particles, thus allowing host proteins and small molecules to access the native capsid while improving cryo–electron microscopy image quality. Using cryo–electron tomography and subtomogram averaging, we determined the structures of native capsomers in the presence and absence of inositol hexakisphosphate (IP6) and cyclophilin A and constructed an all-atom model of a complete HIV-1 capsid. Our structures reveal two IP6 binding sites and modes of cyclophilin A interactions. Free energy calculations substantiate the two binding sites at R18 and K25 and further show a prohibitive energy barrier for IP6 to pass through the pentamer. Our results demonstrate that perfringolysin O perforation is a valuable tool for structural analyses of enveloped virus capsids and interactions with host cell factors.
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Affiliation(s)
- Tao Ni
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Yanan Zhu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Zhengyi Yang
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Chaoyi Xu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA
| | - Yuriy Chaban
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Tanya Nesterova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA
| | - Jiying Ning
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Till Böcking
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW, Sydney, Australia
| | - Michael W. Parker
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Christina Monnie
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jinwoo Ahn
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Juan R. Perilla
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA
| | - 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
- Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford OX3 7BN, UK
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19
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Shen Q, Wu C, Freniere C, Tripler TN, Xiong Y. Nuclear Import of HIV-1. Viruses 2021; 13:2242. [PMID: 34835048 PMCID: PMC8619967 DOI: 10.3390/v13112242] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/26/2021] [Accepted: 11/01/2021] [Indexed: 12/12/2022] Open
Abstract
The delivery of the HIV-1 genome into the nucleus is an indispensable step in retroviral infection of non-dividing cells, but the mechanism of HIV-1 nuclear import has been a longstanding debate due to controversial experimental evidence. It was commonly believed that the HIV-1 capsid would need to disassemble (uncoat) in the cytosol before nuclear import because the capsid is larger than the central channel of nuclear pore complexes (NPCs); however, increasing evidence demonstrates that intact, or nearly intact, HIV-1 capsid passes through the NPC to enter the nucleus. With the protection of the capsid, the HIV-1 core completes reverse transcription in the nucleus and is translocated to the integration site. Uncoating occurs while, or after, the viral genome is released near the integration site. These independent discoveries reveal a compelling new paradigm of this important step of the HIV-1 life cycle. In this review, we summarize the recent studies related to HIV-1 nuclear import, highlighting the spatial-temporal relationship between the nuclear entry of the virus core, reverse transcription, and capsid uncoating.
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Affiliation(s)
| | | | | | | | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA; (Q.S.); (C.W.); (C.F.); (T.N.T.)
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20
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Structure of a Ty1 restriction factor reveals the molecular basis of transposition copy number control. Nat Commun 2021; 12:5590. [PMID: 34552077 PMCID: PMC8458377 DOI: 10.1038/s41467-021-25849-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 09/06/2021] [Indexed: 11/30/2022] Open
Abstract
Excessive replication of Saccharomyces cerevisiae Ty1 retrotransposons is regulated by Copy Number Control, a process requiring the p22/p18 protein produced from a sub-genomic transcript initiated within Ty1 GAG. In retrotransposition, Gag performs the capsid functions required for replication and re-integration. To minimize genomic damage, p22/p18 interrupts virus-like particle function by interaction with Gag. Here, we present structural, biophysical and genetic analyses of p18m, a minimal fragment of Gag that restricts transposition. The 2.8 Å crystal structure of p18m reveals an all α-helical protein related to mammalian and insect ARC proteins. p18m retains the capacity to dimerise in solution and the crystal structures reveal two exclusive dimer interfaces. We probe our findings through biophysical analysis of interface mutants as well as Ty1 transposition and p18m restriction in vivo. Our data provide insight into Ty1 Gag structure and suggest how p22/p18 might function in restriction through a blocking-of-assembly mechanism. In Saccharomyces cerevisiae, unchecked proliferation of Ty1 retrotransposons is controlled by the process of copy number control (CNC), which requires the p22/p18 protein, translated from an internal transcript within the Ty1 GAG gene. Here, the authors present the 2.8 Å crystal structure of a minimal p18 from Ty1-Gag that is able to restrict Ty1 transposition and identify two dimer interfaces in p18, whose roles were probed by mutagenesis both in vitro and in vivo. As p22/p18 contains only one of two conserved domains required for retroelement Gag assembly, they propose that p22/p18-Gag interactions block the Ty1 virus-like particle assembly pathway, resulting in defective particles incapable of supporting retrotransposition.
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21
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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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22
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AlBurtamani N, Paul A, Fassati A. The Role of Capsid in the Early Steps of HIV-1 Infection: New Insights into the Core of the Matter. Viruses 2021; 13:v13061161. [PMID: 34204384 PMCID: PMC8234406 DOI: 10.3390/v13061161] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/10/2021] [Accepted: 06/14/2021] [Indexed: 01/27/2023] Open
Abstract
In recent years, major advances in research and experimental approaches have significantly increased our knowledge on the role of the HIV-1 capsid in the virus life cycle, from reverse transcription to integration and gene expression. This makes the capsid protein a good pharmacological target to inhibit HIV-1 replication. This review covers our current understanding of the role of the viral capsid in the HIV-1 life cycle and its interaction with different host factors that enable reverse transcription, trafficking towards the nucleus, nuclear import and integration into host chromosomes. It also describes different promising small molecules, some of them in clinical trials, as potential targets for HIV-1 therapy.
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23
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Li Z, Wang J, Shen R, Chen N, Qin X, Wang W, Yuan Q. Topological Radiated Dendrites Featuring Persistent Bactericidal Activity for Daily Personal Protection. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2100562. [PMID: 33969623 DOI: 10.1002/smll.202100562] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/09/2021] [Indexed: 06/12/2023]
Abstract
Many substances in nature show radiated topological structure and possess excellent bio-adhesion ability. Herein, regulating the topological structure of Zn2 GeO4 :Mn persistent phosphors is achieved with a molecular coordination method. The morphology of the Zn2 GeO4 :Mn phosphors is well-tuned from nanorods to radiated dendrites by changing the coordination capability of the surface ligand. Due to the structural matching and multivalent interactions, Zn2 GeO4 :Mn radiated dendrites show strong adhesion affinity toward organisms. Moreover, the porous radiated structure offers Zn2 GeO4 :Mn with a large surface area for photocatalysis. Efficient bacterial adhesion and good long persistent photocatalysis activity are observed in the Zn2 GeO4 :Mn radiated dendrites, which endows Zn2 GeO4 :Mn with persistent antibacterial activity even in the dark. Further, the Zn2 GeO4 :Mn spike flowers loaded fabrics exhibit potent persistent antibacterial properties. Mask and towel fabricated with the antibacterial fabrics can inhibit bacterial growth effectively and no bacteria are observed to pass through the antibacterial mask, suggesting that antibacterial mask can guarantee our health and can be utilized repeatedly. The developed Zn2 GeO4 :Mn dendrites possess ideal ability in long-term bacterial inhibition, making them valuable in the fields of medical protection and food packaging.
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Affiliation(s)
- Zhiheng Li
- Key Laboratory of Biomedical Polymers of Ministry of Education, College of Chemistry and Molecular Sciences, School of Microelectronics, Wuhan University, Wuhan, 430072, China
| | - Jie Wang
- Key Laboratory of Biomedical Polymers of Ministry of Education, College of Chemistry and Molecular Sciences, School of Microelectronics, Wuhan University, Wuhan, 430072, China
| | - Ruichen Shen
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Na Chen
- Key Laboratory of Biomedical Polymers of Ministry of Education, College of Chemistry and Molecular Sciences, School of Microelectronics, Wuhan University, Wuhan, 430072, China
| | - Xinyuan Qin
- Key Laboratory of Biomedical Polymers of Ministry of Education, College of Chemistry and Molecular Sciences, School of Microelectronics, Wuhan University, Wuhan, 430072, China
| | - Wenjie Wang
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Quan Yuan
- Key Laboratory of Biomedical Polymers of Ministry of Education, College of Chemistry and Molecular Sciences, School of Microelectronics, Wuhan University, Wuhan, 430072, China
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
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24
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Structure of the mature Rous sarcoma virus lattice reveals a role for IP6 in the formation of the capsid hexamer. Nat Commun 2021; 12:3226. [PMID: 34050170 PMCID: PMC8163826 DOI: 10.1038/s41467-021-23506-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 05/03/2021] [Indexed: 02/08/2023] Open
Abstract
Inositol hexakisphosphate (IP6) is an assembly cofactor for HIV-1. We report here that IP6 is also used for assembly of Rous sarcoma virus (RSV), a retrovirus from a different genus. IP6 is ~100-fold more potent at promoting RSV mature capsid protein (CA) assembly than observed for HIV-1 and removal of IP6 in cells reduces infectivity by 100-fold. Here, visualized by cryo-electron tomography and subtomogram averaging, mature capsid-like particles show an IP6-like density in the CA hexamer, coordinated by rings of six lysines and six arginines. Phosphate and IP6 have opposing effects on CA in vitro assembly, inducing formation of T = 1 icosahedrons and tubes, respectively, implying that phosphate promotes pentamer and IP6 hexamer formation. Subtomogram averaging and classification optimized for analysis of pleomorphic retrovirus particles reveal that the heterogeneity of mature RSV CA polyhedrons results from an unexpected, intrinsic CA hexamer flexibility. In contrast, the CA pentamer forms rigid units organizing the local architecture. These different features of hexamers and pentamers determine the structural mechanism to form CA polyhedrons of variable shape in mature RSV particles.
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25
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Arhel NJ. [An unprecedented interest for the human immunodeficiency virus capsid]. Med Sci (Paris) 2021; 37:549-552. [PMID: 34003105 DOI: 10.1051/medsci/2021050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Nathalie Jane Arhel
- Institut de recherche en infectiologie de Montpellier (IRIM), CNRS UMR9004, Université de Montpellier, 1919 route de Mende, 34090 Montpellier, France
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26
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Perilla JR, Hadden-Perilla JA, Gronenborn AM, Polenova T. Integrative structural biology of HIV-1 capsid protein assemblies: combining experiment and computation. Curr Opin Virol 2021; 48:57-64. [PMID: 33901736 DOI: 10.1016/j.coviro.2021.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/11/2021] [Accepted: 03/20/2021] [Indexed: 12/31/2022]
Abstract
HIV-1 is the causative agent of acquired immunodeficiency syndrome (AIDS), a global pandemic that has claimed 32.7 million lives since 1981. Despite decades of research, there is no cure for the disease, with 38 million people currently infected with HIV. Attractive therapeutic targets for drug development are mature HIV-1 capsids, immature Gag polyprotein assemblies, and Gag maturation intermediates, although their complex architectures, pleomorphism, and dynamics render these assemblies challenging for structural biology. The recent development of integrative approaches, combining experimental and computational methods has enabled atomic-level characterization of structures and dynamics of capsid and Gag assemblies, and revealed their interactions with small-molecule inhibitors and host factors. These structures provide important insights that will guide the development of capsid and maturation inhibitors.
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Affiliation(s)
- Juan R Perilla
- University of Delaware, Department of Chemistry and Biochemistry, Newark, DE, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Jodi A Hadden-Perilla
- University of Delaware, Department of Chemistry and Biochemistry, Newark, DE, United States
| | - Angela M Gronenborn
- Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Ave., Pittsburgh, PA 15261, United States.
| | - Tatyana Polenova
- University of Delaware, Department of Chemistry and Biochemistry, Newark, DE, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
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Mendonça L, Sun D, Ning J, Liu J, Kotecha A, Olek M, Frosio T, Fu X, Himes BA, Kleinpeter AB, Freed EO, Zhou J, Aiken C, Zhang P. CryoET structures of immature HIV Gag reveal six-helix bundle. Commun Biol 2021; 4:481. [PMID: 33863979 PMCID: PMC8052356 DOI: 10.1038/s42003-021-01999-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/18/2021] [Indexed: 11/09/2022] Open
Abstract
Gag is the HIV structural precursor protein which is cleaved by viral protease to produce mature infectious viruses. Gag is a polyprotein composed of MA (matrix), CA (capsid), SP1, NC (nucleocapsid), SP2 and p6 domains. SP1, together with the last eight residues of CA, have been hypothesized to form a six-helix bundle responsible for the higher-order multimerization of Gag necessary for HIV particle assembly. However, the structure of the complete six-helix bundle has been elusive. Here, we determined the structures of both Gag in vitro assemblies and Gag viral-like particles (VLPs) to 4.2 Å and 4.5 Å resolutions using cryo-electron tomography and subtomogram averaging by emClarity. A single amino acid mutation (T8I) in SP1 stabilizes the six-helix bundle, allowing to discern the entire CA-SP1 helix connecting to the NC domain. These structures provide a blueprint for future development of small molecule inhibitors that can lock SP1 in a stable helical conformation, interfere with virus maturation, and thus block HIV-1 infection.
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Affiliation(s)
- Luiza Mendonça
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Dapeng Sun
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jiying Ning
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jiwei Liu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Abhay Kotecha
- Thermo Fisher Scientific, Eindhoven, The Netherlands
| | - Mateusz Olek
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
- Department of Chemistry, University of York, York, UK
| | - Thomas Frosio
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | - Xiaofeng Fu
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Benjamin A Himes
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Alex B Kleinpeter
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Eric O Freed
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Jing Zhou
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Christopher Aiken
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK.
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28
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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)
- Elenia Toccafondi
- CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Université de Strasbourg, Strasbourg, France
| | - 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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29
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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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30
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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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31
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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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32
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Bedwell GJ, Engelman AN. Factors that mold the nuclear landscape of HIV-1 integration. Nucleic Acids Res 2021; 49:621-635. [PMID: 33337475 PMCID: PMC7826272 DOI: 10.1093/nar/gkaa1207] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 11/26/2020] [Indexed: 12/17/2022] Open
Abstract
The integration of retroviral reverse transcripts into the chromatin of the cells that they infect is required for virus replication. Retroviral integration has far-reaching consequences, from perpetuating deadly human diseases to molding metazoan evolution. The lentivirus human immunodeficiency virus 1 (HIV-1), which is the causative agent of the AIDS pandemic, efficiently infects interphase cells due to the active nuclear import of its preintegration complex (PIC). To enable integration, the PIC must navigate the densely-packed nuclear environment where the genome is organized into different chromatin states of varying accessibility in accordance with cellular needs. The HIV-1 capsid protein interacts with specific host factors to facilitate PIC nuclear import, while additional interactions of viral integrase, the enzyme responsible for viral DNA integration, with cellular nuclear proteins and nucleobases guide integration to specific chromosomal sites. HIV-1 integration favors transcriptionally active chromatin such as speckle-associated domains and disfavors heterochromatin including lamina-associated domains. In this review, we describe virus-host interactions that facilitate HIV-1 PIC nuclear import and integration site targeting, highlighting commonalities among factors that participate in both of these steps. We moreover discuss how the nuclear landscape influences HIV-1 integration site selection as well as the establishment of active versus latent virus infection.
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Affiliation(s)
- Gregory J Bedwell
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
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33
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Samsudin F, Gan SKE, Bond PJ. The impact of Gag non-cleavage site mutations on HIV-1 viral fitness from integrative modelling and simulations. Comput Struct Biotechnol J 2020; 19:330-342. [PMID: 33425260 PMCID: PMC7779841 DOI: 10.1016/j.csbj.2020.12.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 01/19/2023] Open
Abstract
The high mutation rate in retroviruses is one of the leading causes of drug resistance. In human immunodeficiency virus type-1 (HIV-1), synergistic mutations in its protease and the protease substrate - the Group-specific antigen (Gag) polyprotein - work together to confer drug resistance against protease inhibitors and compensate the mutations affecting viral fitness. Some Gag mutations can restore Gag-protease binding, yet most Gag-protease correlated mutations occur outside of the Gag cleavage site. To investigate the molecular basis for this, we now report multiscale modelling approaches to investigate various sequentially cleaved Gag products in the context of clinically relevant mutations that occur outside of the cleavage sites, including simulations of the largest Gag proteolytic product in its viral membrane-bound state. We found that some mutations, such as G123E and H219Q, involve direct interaction with cleavage site residues to influence their local environment, while certain mutations in the matrix domain lead to the enrichment of lipids important for Gag targeting and assembly. Collectively, our results reveal why non-cleavage site mutations have far-reaching implications outside of Gag proteolysis, with important consequences for drugging Gag maturation intermediates and tackling protease inhibitor resistance.
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Affiliation(s)
- Firdaus Samsudin
- Bioinformatics Institute (A*STAR), 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
| | - Samuel Ken-En Gan
- Bioinformatics Institute (A*STAR), 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
- Antibody & Product Development Lab – Large Molecule Innovation, Experimental Drug Development Centre (A*STAR), 138670 Singapore, Singapore
- p53 Laboratory (A*STAR), 138648 Singapore, Singapore
| | - Peter J. Bond
- Bioinformatics Institute (A*STAR), 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
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34
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Liu C, Mendonça L, Yang Y, Gao Y, Shen C, Liu J, Ni T, Ju B, Liu C, Tang X, Wei J, Ma X, Zhu Y, Liu W, Xu S, Liu Y, Yuan J, Wu J, Liu Z, Zhang Z, Liu L, Wang P, Zhang P. The Architecture of Inactivated SARS-CoV-2 with Postfusion Spikes Revealed by Cryo-EM and Cryo-ET. Structure 2020; 28:1218-1224.e4. [PMID: 33058760 PMCID: PMC7557167 DOI: 10.1016/j.str.2020.10.001] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/23/2020] [Accepted: 09/30/2020] [Indexed: 12/13/2022]
Abstract
The ongoing global pandemic of coronavirus disease 2019 (COVID-19) resulted from the outbreak of SARS-CoV-2 in December 2019. Currently, multiple efforts are being made to rapidly develop vaccines and treatments to fight COVID-19. Current vaccine candidates use inactivated SARS-CoV-2 viruses; therefore, it is important to understand the architecture of inactivated SARS-CoV-2. We have genetically and structurally characterized β-propiolactone-inactivated viruses from a propagated and purified clinical strain of SARS-CoV-2. We observed that the virus particles are roughly spherical or moderately pleiomorphic. Although a small fraction of prefusion spikes are found, most spikes appear nail shaped, thus resembling a postfusion state, where the S1 protein of the spike has disassociated from S2. Cryoelectron tomography and subtomogram averaging of these spikes yielded a density map that closely matches the overall structure of the SARS-CoV postfusion spike and its corresponding glycosylation site. Our findings have major implications for SARS-CoV-2 vaccine design, especially those using inactivated viruses. β-propiolactone-inactivated SARS-CoV-2 viruses display postfusion spikes Cryo-ET structure of SARS-CoV-2 postfusion spikes was determined at 11 Å resolution This study calls for crucial structural characterization of vaccine candidates
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Affiliation(s)
- Chuang Liu
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China; Cryo-EM Center, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Luiza Mendonça
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Yang Yang
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China
| | - Yuanzhu Gao
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China; Cryo-EM Center, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Chenguang Shen
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China
| | - Jiwei Liu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Tao Ni
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Bin Ju
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China
| | - Congcong Liu
- Cryo-EM Center, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China; The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Xian Tang
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China
| | - Jinli Wei
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China
| | - Xiaomin Ma
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China; Cryo-EM Center, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Yanan Zhu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Weilong Liu
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China
| | - Shuman Xu
- Cryo-EM Center, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Yingxia Liu
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China; Department for Infectious Diseases, Shenzhen Third People's Hospital, Shenzhen, Guangdong Province 518112, China; The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Jing Yuan
- Department for Infectious Diseases, Shenzhen Third People's Hospital, Shenzhen, Guangdong Province 518112, China
| | - Jing Wu
- Cryo-EM Center, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Zheng Liu
- Cryo-EM Center, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Zheng Zhang
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China; The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China.
| | - Lei Liu
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen 518112, Guangdong Province, China; The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China.
| | - Peiyi Wang
- Department of Biology, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China; Cryo-EM Center, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China.
| | - 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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Abstract
From cellular deposition of the HIV-1 capsid to integration of the viral genome, the capsid constitutes a primary target of a variety of host proteins that work to either promote or inhibit HIV-1 infection. Successful progression of HIV-1 infection depends on interactions between the capsid and host factors involved in stability, cellular transport, nuclear import, and genome integration. The virus must also guard its reverse-transcribing genome inside the capsid from host restriction factors that bind the capsid and suppress infection. Understanding the structure and dynamics of the capsid protein (CA) component and the assembled capsid sheds light on the molecular underpinnings of overall capsid stability, architecture, and flexibility that govern HIV-1 capsid–host interactions. The vast majority of these interactions are mediated through recognition of higher order interfaces only present in the assembled capsid lattice. Patterns formed at these interfaces serve as signposts for capsid-binders. Here we provide a graphical summary of the intricate interactions between host factors and the HIV-1 capsid while highlighting recent research. Insights into how host proteins interact with the capsid is crucial for understanding the HIV-1 replication cycle and developing antiviral therapeutics to prevent viral genome integration.
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