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Bonnard D, Le Rouzic E, Singer MR, Yu Z, Le Strat F, Batisse C, Batisse J, Amadori C, Chasset S, Pye VE, Emiliani S, Ledoussal B, Ruff M, Moreau F, Cherepanov P, Benarous R. Biological and Structural Analyses of New Potent Allosteric Inhibitors of HIV-1 Integrase. Antimicrob Agents Chemother 2023; 67:e0046223. [PMID: 37310224 PMCID: PMC10353390 DOI: 10.1128/aac.00462-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/08/2023] [Indexed: 06/14/2023] Open
Abstract
HIV-1 integrase-LEDGF allosteric inhibitors (INLAIs) share the binding site on the viral protein with the host factor LEDGF/p75. These small molecules act as molecular glues promoting hyper-multimerization of HIV-1 IN protein to severely perturb maturation of viral particles. Herein, we describe a new series of INLAIs based on a benzene scaffold that display antiviral activity in the single digit nanomolar range. Akin to other compounds of this class, the INLAIs predominantly inhibit the late stages of HIV-1 replication. A series of high-resolution crystal structures revealed how these small molecules engage the catalytic core and the C-terminal domains of HIV-1 IN. No antagonism was observed between our lead INLAI compound BDM-2 and a panel of 16 clinical antiretrovirals. Moreover, we show that compounds retained high antiviral activity against HIV-1 variants resistant to IN strand transfer inhibitors and other classes of antiretroviral drugs. The virologic profile of BDM-2 and the recently completed single ascending dose phase I trial (ClinicalTrials.gov identifier: NCT03634085) warrant further clinical investigation for use in combination with other antiretroviral drugs. Moreover, our results suggest routes for further improvement of this emerging drug class.
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Affiliation(s)
| | | | - Matthew R. Singer
- Chromatin Structure and Mobile DNA Laboratory, Francis Crick Institute, London, United Kingdom
| | - Zhe Yu
- Chromatin Structure and Mobile DNA Laboratory, Francis Crick Institute, London, United Kingdom
| | | | - Claire Batisse
- IGBMC, INSERM, CNRS, Université de Strasbourg, Illkirch, France
| | - Julien Batisse
- IGBMC, INSERM, CNRS, Université de Strasbourg, Illkirch, France
| | - Céline Amadori
- Biodim, Romainville, France
- Université Paris Cité, Institut Cochin, INSERM, CNRS, Paris, France
| | | | - Valerie E. Pye
- Chromatin Structure and Mobile DNA Laboratory, Francis Crick Institute, London, United Kingdom
| | | | | | - Marc Ruff
- IGBMC, INSERM, CNRS, Université de Strasbourg, Illkirch, France
| | | | - Peter Cherepanov
- Chromatin Structure and Mobile DNA Laboratory, Francis Crick Institute, London, United Kingdom
- Department of Infectious Disease, St. Mary's Campus, Imperial College London, London, United Kingdom
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2
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Eilers G, Gupta K, Allen A, Montermoso S, Murali H, Sharp R, Hwang Y, Bushman FD, Van Duyne G. Structure of a HIV-1 IN-Allosteric inhibitor complex at 2.93 Å resolution: Routes to inhibitor optimization. PLoS Pathog 2023; 19:e1011097. [PMID: 36867659 PMCID: PMC10016701 DOI: 10.1371/journal.ppat.1011097] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 03/15/2023] [Accepted: 01/03/2023] [Indexed: 03/04/2023] Open
Abstract
HIV integrase (IN) inserts viral DNA into the host genome and is the target of the strand transfer inhibitors (STIs), a class of small molecules currently in clinical use. Another potent class of antivirals is the allosteric inhibitors of integrase, or ALLINIs. ALLINIs promote IN aggregation by stabilizing an interaction between the catalytic core domain (CCD) and carboxy-terminal domain (CTD) that undermines viral particle formation in late replication. Ongoing challenges with inhibitor potency, toxicity, and viral resistance motivate research to understand their mechanism. Here, we report a 2.93 Å X-ray crystal structure of the minimal ternary complex between CCD, CTD, and the ALLINI BI-224436. This structure reveals an asymmetric ternary complex with a prominent network of π-mediated interactions that suggest specific avenues for future ALLINI development and optimization.
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Affiliation(s)
- Grant Eilers
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kushol Gupta
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Audrey Allen
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Saira Montermoso
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hemma Murali
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Robert Sharp
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Young Hwang
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Frederic D. Bushman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gregory Van Duyne
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Singer MR, Dinh T, Levintov L, Annamalai AS, Rey JS, Briganti L, Cook NJ, Pye VE, Taylor IA, Kim K, Engelman AN, Kim B, Perilla JR, Kvaratskhelia M, Cherepanov P. The Drug-Induced Interface That Drives HIV-1 Integrase Hypermultimerization and Loss of Function. mBio 2023; 14:e0356022. [PMID: 36744954 PMCID: PMC9973045 DOI: 10.1128/mbio.03560-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/03/2023] [Indexed: 02/07/2023] Open
Abstract
Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are an emerging class of small molecules that disrupt viral maturation by inducing the aberrant multimerization of IN. Here, we present cocrystal structures of HIV-1 IN with two potent ALLINIs, namely, BI-D and the drug candidate Pirmitegravir. The structures reveal atomistic details of the ALLINI-induced interface between the HIV-1 IN catalytic core and carboxyl-terminal domains (CCD and CTD). Projecting from their principal binding pocket on the IN CCD dimer, the compounds act as molecular glue by engaging a triad of invariant HIV-1 IN CTD residues, namely, Tyr226, Trp235, and Lys266, to nucleate the CTD-CCD interaction. The drug-induced interface involves the CTD SH3-like fold and extends to the beginning of the IN carboxyl-terminal tail region. We show that mutations of HIV-1 IN CTD residues that participate in the interface with the CCD greatly reduce the IN-aggregation properties of Pirmitegravir. Our results explain the mechanism of the ALLINI-induced condensation of HIV-1 IN and provide a reliable template for the rational development of this series of antiretrovirals through the optimization of their key contacts with the viral target. IMPORTANCE Despite the remarkable success of combination antiretroviral therapy, HIV-1 remains among the major causes of human suffering and loss of life in poor and developing nations. To prevail in this drawn-out battle with the pandemic, it is essential to continue developing advanced antiviral agents to fight drug resistant HIV-1 variants. Allosteric integrase inhibitors (ALLINIs) are an emerging class of HIV-1 antagonists that are orthogonal to the current antiretroviral drugs. These small molecules act as highly specific molecular glue, which triggers the aggregation of HIV-1 integrase. In this work, we present high-resolution crystal structures that reveal the crucial interactions made by two potent ALLINIs, namely, BI-D and Pirmitegravir, with HIV-1 integrase. Our results explain the mechanism of drug action and will inform the development of this promising class of small molecules for future use in antiretroviral regimens.
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Affiliation(s)
- Matthew R. Singer
- Chromatin Structure & Mobile DNA Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Tung Dinh
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Lev Levintov
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
| | - Arun S. Annamalai
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Juan S. Rey
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
| | - Lorenzo Briganti
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Nicola J. Cook
- Chromatin Structure & Mobile DNA Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Valerie E. Pye
- Chromatin Structure & Mobile DNA Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Ian A. Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, United Kingdom
| | | | - 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
| | - Baek Kim
- Center for Drug Discovery, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Juan R. Perilla
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
| | - Mamuka Kvaratskhelia
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, Colorado, USA
| | - Peter Cherepanov
- Chromatin Structure & Mobile DNA Laboratory, The Francis Crick Institute, London, United Kingdom
- Department of Infectious Disease, St-Mary's Campus, Imperial College London, London, United Kingdom
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Taoda Y, Sugiyama S, Seki T. New designs for HIV-1 integrase inhibitors: a patent review (2018-present). Expert Opin Ther Pat 2023; 33:51-66. [PMID: 36750766 DOI: 10.1080/13543776.2023.2178300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Combination antiretroviral therapy (cART) has dramatically reduced morbidity and mortality of HIV-1-infected patients. Integrase strand transfer inhibitors (INSTIs) play an important role as a key drug in cART. The second-generation INSTIs are very potent, but due to the emergence of highly resistant viruses and the demand for more conveniently usable drugs, the development of 'third-generation' INSTIs and mechanistically different inhibitors is actively being pursued. AREAS COVERED This article reviews the patents (from 2018 to the present) for two classes of HIV-1 integrase inhibitors of INSTIs and integrase-LEDGF/p75 allosteric inhibitors (INLAIs). EXPERT OPINION Since the approval of the second-generation INSTI dolutegravir, the design of new INSTIs has been mostly focused on its scaffold, carbamoylpyridone (CAP). This CAP scaffold is used not only for HIV-1 INSTIs but also for drug discoveries targeting other viral enzymes. With the approval of cabotegravir as a regimen of long-acting injection in combination with rilpivirine, there is a growing need for longer-acting agents. INLAIs have been intensely studied by many groups but have yet to reach the market. However, INLAIs have recently been reported to also function as a latency promoting agent (LPA), indicating further development possibilities.
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Affiliation(s)
- Yoshiyuki Taoda
- Laboratory for Medicinal Chemistry Research, Shionogi Pharmaceutical Research Center, Shionogi & Co., Ltd, Toyonaka-shi, Japan
| | - Shuichi Sugiyama
- Laboratory for Medicinal Chemistry Research, Shionogi Pharmaceutical Research Center, Shionogi & Co., Ltd, Toyonaka-shi, Japan
| | - Takahiro Seki
- Laboratory for Medicinal Chemistry Research, Shionogi Pharmaceutical Research Center, Shionogi & Co., Ltd, Toyonaka-shi, Japan
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Rocchi C, Louvat C, Miele AE, Batisse J, Guillon C, Ballut L, Lener D, Negroni M, Ruff M, Gouet P, Fiorini F. The HIV-1 Integrase C-Terminal Domain Induces TAR RNA Structural Changes Promoting Tat Binding. Int J Mol Sci 2022; 23:13742. [PMID: 36430221 PMCID: PMC9692563 DOI: 10.3390/ijms232213742] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 10/28/2022] [Accepted: 11/03/2022] [Indexed: 11/10/2022] Open
Abstract
Recent evidence indicates that the HIV-1 Integrase (IN) binds the viral genomic RNA (gRNA), playing a critical role in the morphogenesis of the viral particle and in the stability of the gRNA once in the host cell. By combining biophysical, molecular biology, and biochemical approaches, we found that the 18-residues flexible C-terminal tail of IN acts as a sensor of the peculiar apical structure of the trans-activation response element RNA (TAR), interacting with its hexaloop. We show that the binding of the whole IN C-terminal domain modifies TAR structure, exposing critical nucleotides. These modifications favour the subsequent binding of the HIV transcriptional trans-activator Tat to TAR, finally displacing IN from TAR. Based on these results, we propose that IN assists the binding of Tat to TAR RNA. This working model provides a mechanistic sketch accounting for the emerging role of IN in the early stages of proviral transcription and could help in the design of anti-HIV-1 therapeutics against this new target of the viral infectious cycle.
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Affiliation(s)
- Cecilia Rocchi
- Molecular Microbiology and Structural Biochemistry, MMSB-IBCP, UMR 5086, CNRS, University of Lyon, 7 Passage du Vercors, CEDEX 07, 69367 Lyon, France
| | - Camille Louvat
- Molecular Microbiology and Structural Biochemistry, MMSB-IBCP, UMR 5086, CNRS, University of Lyon, 7 Passage du Vercors, CEDEX 07, 69367 Lyon, France
| | - Adriana Erica Miele
- Institute of Analytical Sciences, UMR 5280 CNRS UCBL University of Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
- Department of Biochemical Sciences, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Julien Batisse
- Chromatin Stability and DNA Mobility, Department of Integrated Structural Biology, IGBMC, CNRS, UMR 7104—Inserm U 158, University of Strasbourg, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Christophe Guillon
- Molecular Microbiology and Structural Biochemistry, MMSB-IBCP, UMR 5086, CNRS, University of Lyon, 7 Passage du Vercors, CEDEX 07, 69367 Lyon, France
| | - Lionel Ballut
- Molecular Microbiology and Structural Biochemistry, MMSB-IBCP, UMR 5086, CNRS, University of Lyon, 7 Passage du Vercors, CEDEX 07, 69367 Lyon, France
| | - Daniela Lener
- RNA Architecture and Reactivity, IBMC, CNRS, UPR 9002, University of Strasbourg, 2, Allée Konrad Roentgen, 67084 Strasbourg, France
| | - Matteo Negroni
- RNA Architecture and Reactivity, IBMC, CNRS, UPR 9002, University of Strasbourg, 2, Allée Konrad Roentgen, 67084 Strasbourg, France
| | - Marc Ruff
- Chromatin Stability and DNA Mobility, Department of Integrated Structural Biology, IGBMC, CNRS, UMR 7104—Inserm U 158, University of Strasbourg, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Patrice Gouet
- Molecular Microbiology and Structural Biochemistry, MMSB-IBCP, UMR 5086, CNRS, University of Lyon, 7 Passage du Vercors, CEDEX 07, 69367 Lyon, France
| | - Francesca Fiorini
- Molecular Microbiology and Structural Biochemistry, MMSB-IBCP, UMR 5086, CNRS, University of Lyon, 7 Passage du Vercors, CEDEX 07, 69367 Lyon, France
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Allosteric Integrase Inhibitor Influences on HIV-1 Integration and Roles of LEDGF/p75 and HDGFL2 Host Factors. Viruses 2022; 14:v14091883. [PMID: 36146690 PMCID: PMC9502684 DOI: 10.3390/v14091883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/11/2022] [Accepted: 08/24/2022] [Indexed: 02/01/2023] Open
Abstract
Allosteric integrase (IN) inhibitors (ALLINIs), which are promising preclinical compounds that engage the lens epithelium-derived growth factor (LEDGF)/p75 binding site on IN, can inhibit different aspects of human immunodeficiency virus 1 (HIV-1) replication. During the late phase of replication, ALLINIs induce aberrant IN hyper-multimerization, the consequences of which disrupt IN binding to genomic RNA and virus particle morphogenesis. During the early phase of infection, ALLINIs can suppress HIV-1 integration into host genes, which is also observed in LEDGF/p75-depelted cells. Despite this similarity, the roles of LEDGF/p75 and its paralog hepatoma-derived growth factor like 2 (HDGFL2) in ALLINI-mediated integration retargeting are untested. Herein, we mapped integration sites in cells knocked out for LEDGF/p75, HDGFL2, or both factors, which revealed that these two proteins in large part account for ALLINI-mediated integration retargeting during the early phase of infection. We also determined that ALLINI-treated viruses are defective during the subsequent round of infection for integration into genes associated with speckle-associated domains, which are naturally highly targeted for HIV-1 integration. Class II IN mutant viruses with alterations distal from the LEDGF/p75 binding site moreover shared this integration retargeting phenotype. Altogether, our findings help to inform the molecular bases and consequences of ALLINI action.
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Rocchi C, Gouet P, Parissi V, Fiorini F. The C-Terminal Domain of HIV-1 Integrase: A Swiss Army Knife for the Virus? Viruses 2022; 14:v14071397. [PMID: 35891378 PMCID: PMC9316232 DOI: 10.3390/v14071397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 12/31/2022] Open
Abstract
Retroviral integrase is a multimeric enzyme that catalyzes the integration of reverse-transcribed viral DNA into the cellular genome. Beyond integration, the Human immunodeficiency virus type 1 (HIV-1) integrase is also involved in many other steps of the viral life cycle, such as reverse transcription, nuclear import, virion morphogenesis and proviral transcription. All these additional functions seem to depend on the action of the integrase C-terminal domain (CTD) that works as a molecular hub, interacting with many different viral and cellular partners. In this review, we discuss structural issues concerning the CTD, with particular attention paid to its interaction with nucleic acids. We also provide a detailed map of post-translational modifications and interaction with molecular partners.
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Affiliation(s)
- Cecilia Rocchi
- Molecular Microbiology and Structural Biochemistry (MMSB), CNRS, University of Lyon 1, UMR 5086, 69367 Lyon, France; (C.R.); (P.G.)
- Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), 33076 Bordeaux, France;
| | - Patrice Gouet
- Molecular Microbiology and Structural Biochemistry (MMSB), CNRS, University of Lyon 1, UMR 5086, 69367 Lyon, France; (C.R.); (P.G.)
- Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), 33076 Bordeaux, France;
| | - Vincent Parissi
- Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), 33076 Bordeaux, France;
- Fundamental Microbiology and Pathogenicity (MFP), CNRS, University of Bordeaux, UMR5234, 33405 Bordeaux, France
| | - Francesca Fiorini
- Molecular Microbiology and Structural Biochemistry (MMSB), CNRS, University of Lyon 1, UMR 5086, 69367 Lyon, France; (C.R.); (P.G.)
- Viral DNA Integration and Chromatin Dynamics Network (DyNAVir), 33076 Bordeaux, France;
- Correspondence: ; Tel.: +33-4-72722624; Fax: +33-4-72722616
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Zhou Y, Sotcheff SL, Routh AL. Next-generation sequencing: A new avenue to understand viral RNA-protein interactions. J Biol Chem 2022; 298:101924. [PMID: 35413291 PMCID: PMC8994257 DOI: 10.1016/j.jbc.2022.101924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 04/01/2022] [Accepted: 04/02/2022] [Indexed: 10/25/2022] Open
Abstract
The genomes of RNA viruses present an astonishing source of both sequence and structural diversity. From intracellular viral RNA-host interfaces to interactions between the RNA genome and structural proteins in virus particles themselves, almost the entire viral lifecycle is accompanied by a myriad of RNA-protein interactions that are required to fulfill their replicative potential. It is therefore important to characterize such rich and dynamic collections of viral RNA-protein interactions to understand virus evolution and their adaptation to their hosts and environment. Recent advances in next-generation sequencing technologies have allowed the characterization of viral RNA-protein interactions, including both transient and conserved interactions, where molecular and structural approaches have fallen short. In this review, we will provide a methodological overview of the high-throughput techniques used to study viral RNA-protein interactions, their biochemical mechanisms, and how they evolved from classical methods as well as one another. We will discuss how different techniques have fueled virus research to characterize how viral RNA and proteins interact, both locally and on a global scale. Finally, we will present examples on how these techniques influence the studies of clinically important pathogens such as HIV-1 and SARS-CoV-2.
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Affiliation(s)
- Yiyang Zhou
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Texas, USA.
| | - Stephanea L Sotcheff
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Texas, USA
| | - Andrew L Routh
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Texas, USA; Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Texas, USA; Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
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Engelman AN, Kvaratskhelia M. Multimodal Functionalities of HIV-1 Integrase. Viruses 2022; 14:926. [PMID: 35632668 PMCID: PMC9144474 DOI: 10.3390/v14050926] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/20/2022] [Accepted: 04/26/2022] [Indexed: 01/11/2023] Open
Abstract
Integrase is the retroviral protein responsible for integrating reverse transcripts into cellular genomes. Co-packaged with viral RNA and reverse transcriptase into capsid-encased viral cores, human immunodeficiency virus 1 (HIV-1) integrase has long been implicated in reverse transcription and virion maturation. However, the underlying mechanisms of integrase in these non-catalytic-related viral replication steps have remained elusive. Recent results have shown that integrase binds genomic RNA in virions, and that mutational or pharmacological disruption of integrase-RNA binding yields eccentric virion particles with ribonucleoprotein complexes situated outside of the capsid shell. Such viruses are defective for reverse transcription due to preferential loss of integrase and viral RNA from infected target cells. Parallel research has revealed defective integrase-RNA binding and eccentric particle formation as common features of class II integrase mutant viruses, a phenotypic grouping of viruses that display defects at steps beyond integration. In light of these new findings, we propose three new subclasses of class II mutant viruses (a, b, and c), all of which are defective for integrase-RNA binding and particle morphogenesis, but differ based on distinct underlying mechanisms exhibited by the associated integrase mutant proteins. We also assess how these findings inform the role of integrase in HIV-1 particle maturation.
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Affiliation(s)
- 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
| | - Mamuka Kvaratskhelia
- Division of Infectious Diseases, Anschutz Medical Campus, University of Colorado School of Medicine, Aurora, CO 80045, USA
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Liu S, Koneru PC, Li W, Pathirage C, Engelman AN, Kvaratskhelia M, Musier-Forsyth K. HIV-1 integrase binding to genomic RNA 5'-UTR induces local structural changes in vitro and in virio. Retrovirology 2021; 18:37. [PMID: 34809662 PMCID: PMC8609798 DOI: 10.1186/s12977-021-00582-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 11/03/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND During HIV-1 maturation, Gag and Gag-Pol polyproteins are proteolytically cleaved and the capsid protein polymerizes to form the honeycomb capsid lattice. HIV-1 integrase (IN) binds the viral genomic RNA (gRNA) and impairment of IN-gRNA binding leads to mis-localization of the nucleocapsid protein (NC)-condensed viral ribonucleoprotein complex outside the capsid core. IN and NC were previously demonstrated to bind to the gRNA in an orthogonal manner in virio; however, the effect of IN binding alone or simultaneous binding of both proteins on gRNA structure is not yet well understood. RESULTS Using crosslinking-coupled selective 2'-hydroxyl acylation analyzed by primer extension (XL-SHAPE), we characterized the interaction of IN and NC with the HIV-1 gRNA 5'-untranslated region (5'-UTR). NC preferentially bound to the packaging signal (Psi) and a UG-rich region in U5, irrespective of the presence of IN. IN alone also bound to Psi but pre-incubation with NC largely abolished this interaction. In contrast, IN specifically bound to and affected the nucleotide (nt) dynamics of the apical loop of the transactivation response element (TAR) and the polyA hairpin even in the presence of NC. SHAPE probing of the 5'-UTR RNA in virions produced from allosteric IN inhibitor (ALLINI)-treated cells revealed that while the global secondary structure of the 5'-UTR remained unaltered, the inhibitor treatment induced local reactivity differences, including changes in the apical loop of TAR that are consistent with the in vitro results. CONCLUSIONS Overall, the binding interactions of NC and IN with the 5'-UTR are largely orthogonal in vitro. This study, together with previous probing experiments, suggests that IN and NC binding in vitro and in virio lead to only local structural changes in the regions of the 5'-UTR probed here. Accordingly, disruption of IN-gRNA binding by ALLINI treatment results in local rather than global secondary structure changes of the 5'-UTR in eccentric virus particles.
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Affiliation(s)
- Shuohui Liu
- grid.261331.40000 0001 2285 7943Department of Chemistry and Biochemistry, Centers for RNA Biology and Retroviral Research, The Ohio State University, Columbus, OH USA
| | - Pratibha C. Koneru
- grid.430503.10000 0001 0703 675XDivision of Infectious Diseases, School of Medicine, University of Colorado, Aurora, CO USA
| | - Wen Li
- grid.65499.370000 0001 2106 9910Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA USA ,grid.38142.3c000000041936754XDepartment of Medicine, Harvard Medical School, Boston, MA USA
| | - Chathuri Pathirage
- grid.261331.40000 0001 2285 7943Department of Chemistry and Biochemistry, Centers for RNA Biology and Retroviral Research, The Ohio State University, Columbus, OH USA
| | - Alan N. Engelman
- grid.65499.370000 0001 2106 9910Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA USA ,grid.38142.3c000000041936754XDepartment of Medicine, Harvard Medical School, Boston, MA USA
| | - Mamuka Kvaratskhelia
- grid.430503.10000 0001 0703 675XDivision of Infectious Diseases, School of Medicine, University of Colorado, Aurora, CO USA
| | - Karin Musier-Forsyth
- grid.261331.40000 0001 2285 7943Department of Chemistry and Biochemistry, Centers for RNA Biology and Retroviral Research, The Ohio State University, Columbus, OH USA
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11
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Gupta K, Allen A, Giraldo C, Eilers G, Sharp R, Hwang Y, Murali H, Cruz K, Janmey P, Bushman F, Van Duyne GD. Allosteric HIV Integrase Inhibitors Promote Formation of Inactive Branched Polymers via Homomeric Carboxy-Terminal Domain Interactions. Structure 2021; 29:213-225.e5. [PMID: 33357410 PMCID: PMC7935764 DOI: 10.1016/j.str.2020.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 11/04/2020] [Accepted: 12/04/2020] [Indexed: 12/12/2022]
Abstract
The major effect of allosteric HIV integrase (IN) inhibitors (ALLINIs) is observed during virion maturation, where ALLINI treatment interrupts IN-RNA interactions via drug-induced IN aggregation, leading to the formation of aberrant virions. To understand the structural changes that accompany drug-induced aggregation, we determined the soft matter properties of ALLINI-induced IN aggregates. Using small-angle neutron scattering, SEM, and rheology, we have discovered that the higher-order aggregates induced by ALLINIs have the characteristics of weak three-dimensional gels with a fractal-like character. Their formation is inhibited by the host factor LEDGF/p75, as well as ex vivo resistance substitutions. Mutagenesis and biophysical analyses reveal that homomeric carboxy-terminal domain interactions are required to achieve the branched-polymer nature of the ALLINI-induced aggregates. These studies provide key insight into the mechanisms of ALLINI action and resistance in the context of the crowded virion environment where ALLINIs exert their effect.
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Affiliation(s)
- Kushol Gupta
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA
| | - Audrey Allen
- Department of Microbiology, University of Pennsylvania School of Medicine, 426 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA
| | - Carolina Giraldo
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA
| | - Grant Eilers
- Department of Microbiology, University of Pennsylvania School of Medicine, 426 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA
| | - Robert Sharp
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA
| | - Young Hwang
- Department of Microbiology, University of Pennsylvania School of Medicine, 426 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA
| | - Hemma Murali
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA
| | - Katrina Cruz
- Department of Physiology, and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104-6383, USA
| | - Paul Janmey
- Department of Physiology, and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104-6383, USA
| | - Frederic Bushman
- Department of Microbiology, University of Pennsylvania School of Medicine, 426 Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA.
| | - Gregory D Van Duyne
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, 809C Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19105-6059, USA.
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12
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Capsid Lattice Destabilization Leads to Premature Loss of the Viral Genome and Integrase Enzyme during HIV-1 Infection. J Virol 2020; 95:JVI.00984-20. [PMID: 33115869 DOI: 10.1128/jvi.00984-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/24/2020] [Indexed: 01/28/2023] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) capsid (CA) protein forms a conical lattice around the viral ribonucleoprotein complex (vRNP) consisting of a dimeric viral genome and associated proteins, together constituting the viral core. Upon entry into target cells, the viral core undergoes a process termed uncoating, during which CA molecules are shed from the lattice. Although the timing and degree of uncoating are important for reverse transcription and integration, the molecular basis of this phenomenon remains unclear. Using complementary approaches, we assessed the impact of core destabilization on the intrinsic stability of the CA lattice in vitro and fates of viral core components in infected cells. We found that substitutions in CA can impact the intrinsic stability of the CA lattice in vitro in the absence of vRNPs, which mirrored findings from an assessment of CA stability in virions. Altering CA stability tended to increase the propensity to form morphologically aberrant particles, in which the vRNPs were mislocalized between the CA lattice and the viral lipid envelope. Importantly, destabilization of the CA lattice led to premature dissociation of CA from vRNPs in target cells, which was accompanied by proteasomal-independent losses of the viral genome and integrase enzyme. Overall, our studies show that the CA lattice protects the vRNP from untimely degradation in target cells and provide the mechanistic basis of how CA stability influences reverse transcription.IMPORTANCE The human immunodeficiency virus type 1 (HIV-1) capsid (CA) protein forms a conical lattice around the viral RNA genome and the associated viral enzymes and proteins, together constituting the viral core. Upon infection of a new cell, viral cores are released into the cytoplasm where they undergo a process termed "uncoating," i.e., shedding of CA molecules from the conical lattice. Although proper and timely uncoating has been shown to be important for reverse transcription, the molecular mechanisms that link these two events remain poorly understood. In this study, we show that destabilization of the CA lattice leads to premature dissociation of CA from viral cores, which exposes the viral genome and the integrase enzyme for degradation in target cells. Thus, our studies demonstrate that the CA lattice protects the viral ribonucleoprotein complexes from untimely degradation in target cells and provide the first causal link between how CA stability affects reverse transcription.
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13
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Kleinpeter A, Freed EO. How to package the RNA of HIV-1. eLife 2020; 9:63585. [PMID: 33200986 PMCID: PMC7671680 DOI: 10.7554/elife.63585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 11/11/2020] [Indexed: 11/13/2022] Open
Abstract
Interactions between viral RNA and the integrase enzyme are required for HIV-1 particles to become infectious, a process that can be disrupted through multiple mechanisms.
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Affiliation(s)
- Alex Kleinpeter
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, United States
| | - Eric O Freed
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, United States
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14
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Elliott JL, Eschbach JE, Koneru PC, Li W, Puray-Chavez M, Townsend D, Lawson DQ, Engelman AN, Kvaratskhelia M, Kutluay SB. Integrase-RNA interactions underscore the critical role of integrase in HIV-1 virion morphogenesis. eLife 2020; 9:54311. [PMID: 32960169 PMCID: PMC7671690 DOI: 10.7554/elife.54311] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 09/22/2020] [Indexed: 01/29/2023] Open
Abstract
A large number of human immunodeficiency virus 1 (HIV-1) integrase (IN) alterations, referred to as class II substitutions, exhibit pleiotropic effects during virus replication. However, the underlying mechanism for the class II phenotype is not known. Here we demonstrate that all tested class II IN substitutions compromised IN-RNA binding in virions by one of the three distinct mechanisms: (i) markedly reducing IN levels thus precluding the formation of IN complexes with viral RNA; (ii) adversely affecting functional IN multimerization and consequently impairing IN binding to viral RNA; and (iii) directly compromising IN-RNA interactions without substantially affecting IN levels or functional IN multimerization. Inhibition of IN-RNA interactions resulted in the mislocalization of viral ribonucleoprotein complexes outside the capsid lattice, which led to premature degradation of the viral genome and IN in target cells. Collectively, our studies uncover causal mechanisms for the class II phenotype and highlight an essential role of IN-RNA interactions for accurate virion maturation.
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Affiliation(s)
- Jennifer L Elliott
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Jenna E Eschbach
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Pratibha C Koneru
- Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, United States
| | - Wen Li
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, United States.,Department of Medicine, Harvard Medical School, Boston, United States
| | - Maritza Puray-Chavez
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Dana Townsend
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Dana Q Lawson
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, United States.,Department of Medicine, Harvard Medical School, Boston, United States
| | - Mamuka Kvaratskhelia
- Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, United States
| | - Sebla B Kutluay
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
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15
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Elliott JL, Kutluay SB. Going beyond Integration: The Emerging Role of HIV-1 Integrase in Virion Morphogenesis. Viruses 2020; 12:E1005. [PMID: 32916894 PMCID: PMC7551943 DOI: 10.3390/v12091005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/03/2020] [Accepted: 09/07/2020] [Indexed: 12/22/2022] Open
Abstract
The HIV-1 integrase enzyme (IN) plays a critical role in the viral life cycle by integrating the reverse-transcribed viral DNA into the host chromosome. This function of IN has been well studied, and the knowledge gained has informed the design of small molecule inhibitors that now form key components of antiretroviral therapy regimens. Recent discoveries unveiled that IN has an under-studied yet equally vital second function in human immunodeficiency virus type 1 (HIV-1) replication. This involves IN binding to the viral RNA genome in virions, which is necessary for proper virion maturation and morphogenesis. Inhibition of IN binding to the viral RNA genome results in mislocalization of the viral genome inside the virus particle, and its premature exposure and degradation in target cells. The roles of IN in integration and virion morphogenesis share a number of common elements, including interaction with viral nucleic acids and assembly of higher-order IN multimers. Herein we describe these two functions of IN within the context of the HIV-1 life cycle, how IN binding to the viral genome is coordinated by the major structural protein, Gag, and discuss the value of targeting the second role of IN in virion morphogenesis.
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Affiliation(s)
| | - Sebla B. Kutluay
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA;
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16
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Kleinpeter AB, Freed EO. HIV-1 Maturation: Lessons Learned from Inhibitors. Viruses 2020; 12:E940. [PMID: 32858867 PMCID: PMC7552077 DOI: 10.3390/v12090940] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 02/06/2023] Open
Abstract
Since the emergence of HIV and AIDS in the early 1980s, the development of safe and effective therapies has accompanied a massive increase in our understanding of the fundamental processes that drive HIV biology. As basic HIV research has informed the development of novel therapies, HIV inhibitors have been used as probes for investigating basic mechanisms of HIV-1 replication, transmission, and pathogenesis. This positive feedback cycle has led to the development of highly effective combination antiretroviral therapy (cART), which has helped stall the progression to AIDS, prolong lives, and reduce transmission of the virus. However, to combat the growing rates of virologic failure and toxicity associated with long-term therapy, it is important to diversify our repertoire of HIV-1 treatments by identifying compounds that block additional steps not targeted by current drugs. Most of the available therapeutics disrupt early events in the replication cycle, with the exception of the protease (PR) inhibitors, which act at the virus maturation step. HIV-1 maturation consists of a series of biochemical changes that facilitate the conversion of an immature, noninfectious particle to a mature infectious virion. These changes include proteolytic processing of the Gag polyprotein by the viral protease (PR), structural rearrangement of the capsid (CA) protein, and assembly of individual CA monomers into hexamers and pentamers that ultimately form the capsid. Here, we review the development and therapeutic potential of maturation inhibitors (MIs), an experimental class of anti-HIV-1 compounds with mechanisms of action distinct from those of the PR inhibitors. We emphasize the key insights into HIV-1 biology and structure that the study of MIs has provided. We will focus on three distinct groups of inhibitors that block HIV-1 maturation: (1) compounds that block the processing of the CA-spacer peptide 1 (SP1) cleavage intermediate, the original class of compounds to which the term MI was applied; (2) CA-binding inhibitors that disrupt capsid condensation; and (3) allosteric integrase inhibitors (ALLINIs) that block the packaging of the viral RNA genome into the condensing capsid during maturation. Although these three classes of compounds have distinct structures and mechanisms of action, they share the ability to block the formation of the condensed conical capsid, thereby blocking particle infectivity.
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Affiliation(s)
| | - Eric O. Freed
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA;
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17
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Anderson-Daniels J, Singh PK, Sowd GA, Li W, Engelman AN, Aiken C. Dominant Negative MA-CA Fusion Protein Is Incorporated into HIV-1 Cores and Inhibits Nuclear Entry of Viral Preintegration Complexes. J Virol 2019; 93:e01118-19. [PMID: 31413124 PMCID: PMC6803256 DOI: 10.1128/jvi.01118-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 08/03/2019] [Indexed: 11/20/2022] Open
Abstract
Particle maturation is a critical step in the HIV-1 replication cycle that requires proteolytic cleavage of the Gag polyprotein into its constitutive proteins: the matrix (MA), capsid (CA), nucleocapsid (NC), and p6 proteins. The accurate and efficient cleavage of Gag is essential for virion infectivity; inhibitors of the viral protease are potent antivirals, and substitutions in Gag that prevent its cleavage result in reduced HIV-1 infectivity. In a previous study, a mutation inhibiting cleavage at the MA-CA junction was observed to potently inhibit virus infection: incorporation of small amounts of uncleaved MA-CA protein into HIV-1 particles inhibited infectivity by ∼95%, and the resulting viral particles exhibited aberrant capsids. Here we report a detailed mechanistic analysis of HIV-1 particles bearing uncleaved MA-CA protein. We show that the particles contain stable cores and can efficiently saturate host restriction by TRIMCyp in target cells. We further show that MA-CA associates with CA in particles without detectably affecting the formation of intermolecular CA interfaces. Incorporation of MA-CA did not markedly affect reverse transcription in infected cells, but nuclear entry was impaired and integration targeting was altered. Additionally, results from mutational analysis of Gag revealed that membrane-binding elements of MA contribute to the antiviral activity of uncleaved MA-CA protein. Our results suggest that small amounts of partially processed Gag subunits coassemble with CA during virion maturation, resulting in impaired capsid functions.IMPORTANCE To become infectious, newly formed HIV-1 particles undergo a process of maturation in which the viral polyproteins are cleaved into smaller components. A previous study demonstrated that inclusion of even small quantities of an uncleavable mutant Gag polyprotein results in a strong reduction in virus infectivity. Here we show that the mechanism of transdominant inhibition by uncleavable Gag involves inhibition of nuclear entry and alteration of viral integration sites. Additionally, the results of mutational analysis suggest that the membrane-binding activity of Gag is a major requirement for the antiviral activity. These results further define the antiviral mechanism of uncleavable Gag, which may be useful for exploiting this effect to develop new antivirals.
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Affiliation(s)
- Jordan Anderson-Daniels
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Parmit K Singh
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Gregory A Sowd
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Wen Li
- 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
| | - Christopher Aiken
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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18
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Engelman AN. Multifaceted HIV integrase functionalities and therapeutic strategies for their inhibition. J Biol Chem 2019; 294:15137-15157. [PMID: 31467082 DOI: 10.1074/jbc.rev119.006901] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Antiretroviral inhibitors that are used to manage HIV infection/AIDS predominantly target three enzymes required for virus replication: reverse transcriptase, protease, and integrase. Although integrase inhibitors were the last among this group to be approved for treating people living with HIV, they have since risen to the forefront of treatment options. Integrase strand transfer inhibitors (INSTIs) are now recommended components of frontline and drug-switch antiretroviral therapy formulations. Integrase catalyzes two successive magnesium-dependent polynucleotidyl transferase reactions, 3' processing and strand transfer, and INSTIs tightly bind the divalent metal ions and viral DNA end after 3' processing, displacing from the integrase active site the DNA 3'-hydroxyl group that is required for strand transfer activity. Although second-generation INSTIs present higher barriers to the development of viral drug resistance than first-generation compounds, the mechanisms underlying these superior barrier profiles are incompletely understood. A separate class of HIV-1 integrase inhibitors, the allosteric integrase inhibitors (ALLINIs), engage integrase distal from the enzyme active site, namely at the binding site for the cellular cofactor lens epithelium-derived growth factor (LEDGF)/p75 that helps to guide integration into host genes. ALLINIs inhibit HIV-1 replication by inducing integrase hypermultimerization, which precludes integrase binding to genomic RNA and perturbs the morphogenesis of new viral particles. Although not yet approved for human use, ALLINIs provide important probes that can be used to investigate the link between HIV-1 integrase and viral particle morphogenesis. Herein, I review the mechanisms of retroviral integration as well as the promises and challenges of using integrase inhibitors for HIV/AIDS management.
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Affiliation(s)
- Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215 Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
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19
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Koneru PC, Francis AC, Deng N, Rebensburg SV, Hoyte AC, Lindenberger J, Adu-Ampratwum D, Larue RC, Wempe MF, Engelman AN, Lyumkis D, Fuchs JR, Levy RM, Melikyan GB, Kvaratskhelia M. HIV-1 integrase tetramers are the antiviral target of pyridine-based allosteric integrase inhibitors. eLife 2019; 8:46344. [PMID: 31120420 PMCID: PMC6581505 DOI: 10.7554/elife.46344] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/22/2019] [Indexed: 12/13/2022] Open
Abstract
Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are a promising new class of antiretroviral agents that disrupt proper viral maturation by inducing hyper-multimerization of IN. Here we show that lead pyridine-based ALLINI KF116 exhibits striking selectivity for IN tetramers versus lower order protein oligomers. IN structural features that are essential for its functional tetramerization and HIV-1 replication are also critically important for KF116 mediated higher-order IN multimerization. Live cell imaging of single viral particles revealed that KF116 treatment during virion production compromises the tight association of IN with capsid cores during subsequent infection of target cells. We have synthesized the highly active (-)-KF116 enantiomer, which displayed EC50 of ~7 nM against wild type HIV-1 and ~10 fold higher, sub-nM activity against a clinically relevant dolutegravir resistant mutant virus suggesting potential clinical benefits for complementing dolutegravir therapy with pyridine-based ALLINIs. HIV-1 inserts its genetic code into human genomes, turning healthy cells into virus factories. To do this, the virus uses an enzyme called integrase. Front-line treatments against HIV-1 called “integrase strand-transfer inhibitors” stop this enzyme from working. These inhibitors have helped to revolutionize the treatment of HIV/AIDS by protecting the cells from new infections. But, the emergence of drug resistance remains a serious problem. As the virus evolves, it changes the shape of its integrase protein, substantially reducing the effectiveness of the current therapies. One way to overcome this problem is to develop other therapies that can kill the drug resistant viruses by targeting different parts of the integrase protein. It should be much harder for the virus to evolve the right combination of changes to escape two or more treatments at once. A promising class of new compounds are “allosteric integrase inhibitors”. These chemical compounds target a part of the integrase enzyme that the other treatments do not yet reach. Rather than stopping the integrase enzyme from inserting the viral code into the human genome, the new inhibitors make integrase proteins clump together and prevent the formation of infectious viruses. At the moment, these compounds are still experimental. Before they are ready for use in people, researchers need to better understand how they work, and there are several open questions to answer. Integrase proteins work in groups of four and it is not clear how the new compounds make the integrases form large clumps, or what this does to the virus. Understanding this should allow scientists to develop improved versions of the drugs. To answer these questions, Koneru et al. first examined two of the new compounds. A combination of molecular analysis and computer modelling revealed how they work. The compounds link many separate groups of four integrases with each other to form larger and larger clumps, essentially a snowball effect. Live images of infected cells showed that the clumps of integrase get stuck outside of the virus’s protective casing. This leaves them exposed, allowing the cell to destroy the integrase enzymes. Koneru et al. also made a new compound, called (-)-KF116. Not only was this compound able to tackle normal HIV-1, it could block viruses resistant to the other type of integrase treatment. In fact, in laboratory tests, it was 10 times more powerful against these resistant viruses. Together, these findings help to explain how allosteric integrase inhibitors work, taking scientists a step closer to bringing them into the clinic. In the future, new versions of the compounds, like (-)-KF116, could help to tackle drug resistance in HIV-1.
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Affiliation(s)
- Pratibha C Koneru
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, United States
| | - Ashwanth C Francis
- Division of Infectious Diseases, Department of Pediatrics, Emory University, Atlanta, United States
| | - Nanjie Deng
- Department of Chemistry and Physical Sciences, Pace University, New York, United States
| | - Stephanie V Rebensburg
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, United States
| | - Ashley C Hoyte
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, United States
| | - Jared Lindenberger
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, United States
| | | | - Ross C Larue
- College of Pharmacy, The Ohio State University, Columbus, United States
| | - Michael F Wempe
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, United States
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, United States.,Department of Medicine, Harvard Medical School, Boston, United States
| | - Dmitry Lyumkis
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, United States
| | - James R Fuchs
- College of Pharmacy, The Ohio State University, Columbus, United States
| | - Ronald M Levy
- Department of Chemistry, Temple University, Philadelphia, United States
| | - Gregory B Melikyan
- Division of Infectious Diseases, Department of Pediatrics, Emory University, Atlanta, United States
| | - Mamuka Kvaratskhelia
- Division of Infectious Diseases, School of Medicine, University of Colorado, Aurora, United States
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20
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Anderson EM, Maldarelli F. The role of integration and clonal expansion in HIV infection: live long and prosper. Retrovirology 2018; 15:71. [PMID: 30352600 PMCID: PMC6199739 DOI: 10.1186/s12977-018-0448-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/15/2018] [Indexed: 02/07/2023] Open
Abstract
Integration of viral DNA into the host genome is a central event in the replication cycle and the pathogenesis of retroviruses, including HIV. Although most cells infected with HIV are rapidly eliminated in vivo, HIV also infects long-lived cells that persist during combination antiretroviral therapy (cART). Cells with replication competent HIV proviruses form a reservoir that persists despite cART and such reservoirs are at the center of efforts to eradicate or control infection without cART. The mechanisms of persistence of these chronically infected long-lived cells is uncertain, but recent research has demonstrated that the presence of the HIV provirus has enduring effects on infected cells. Cells with integrated proviruses may persist for many years, undergo clonal expansion, and produce replication competent HIV. Even proviruses with defective genomes can produce HIV RNA and may contribute to ongoing HIV pathogenesis. New analyses of HIV infected cells suggest that over time on cART, there is a shift in the composition of the population of HIV infected cells, with the infected cells that persist over prolonged periods having proviruses integrated in genes associated with regulation of cell growth. In several cases, strong evidence indicates the presence of the provirus in specific genes may determine persistence, proliferation, or both. These data have raised the intriguing possibility that after cART is introduced, a selection process enriches for cells with proviruses integrated in genes associated with cell growth regulation. The dynamic nature of populations of cells infected with HIV during cART is not well understood, but is likely to have a profound influence on the composition of the HIV reservoir with critical consequences for HIV eradication and control strategies. As such, integration studies will shed light on understanding viral persistence and inform eradication and control strategies. Here we review the process of HIV integration, the role that integration plays in persistence, clonal expansion of the HIV reservoir, and highlight current challenges and outstanding questions for future research.
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Affiliation(s)
| | - Frank Maldarelli
- HIV Dynamics and Replication Program, NCI, NIH, Frederick, MD, 21702, USA.
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21
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Bieniasz P, Telesnitsky A. Multiple, Switchable Protein:RNA Interactions Regulate Human Immunodeficiency Virus Type 1 Assembly. Annu Rev Virol 2018; 5:165-183. [PMID: 30048218 DOI: 10.1146/annurev-virology-092917-043448] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) particle assembly requires several protein:RNA interactions that vary widely in their character, from specific recognition of highly conserved and structured viral RNA elements to less specific interactions with variable RNA sequences. Genetic, biochemical, biophysical, and structural studies have illuminated how virion morphogenesis is accompanied by dramatic changes in the interactions among the protein and RNA virion components. The 5' leader RNA element drives RNA recognition by Gag upon initiation of HIV-1 assembly and can assume variable conformations that influence translation, dimerization, and Gag recognition. As Gag multimerizes on the plasma membrane, forming immature particles, its RNA binding specificity transiently changes, enabling recognition of the A-rich composition of the viral genome. Initiation of assembly may also be regulated by occlusion of the membrane binding surface of Gag by tRNA. Finally, recent work has suggested that RNA interactions with viral enzymes may activate and ensure the accuracy of virion maturation.
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Affiliation(s)
- Paul Bieniasz
- Laboratory of Retrovirology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA;
| | - Alice Telesnitsky
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan 48109, USA;
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22
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Engelman AN, Singh PK. Cellular and molecular mechanisms of HIV-1 integration targeting. Cell Mol Life Sci 2018; 75:2491-2507. [PMID: 29417178 PMCID: PMC6004233 DOI: 10.1007/s00018-018-2772-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/23/2018] [Accepted: 02/01/2018] [Indexed: 12/21/2022]
Abstract
Integration is central to HIV-1 replication and helps mold the reservoir of cells that persists in AIDS patients. HIV-1 interacts with specific cellular factors to target integration to interior regions of transcriptionally active genes within gene-dense regions of chromatin. The viral capsid interacts with several proteins that are additionally implicated in virus nuclear import, including cleavage and polyadenylation specificity factor 6, to suppress integration into heterochromatin. The viral integrase protein interacts with transcriptional co-activator lens epithelium-derived growth factor p75 to principally position integration within gene bodies. The integrase additionally senses target DNA distortion and nucleotide sequence to help fine-tune the specific phosphodiester bonds that are cleaved at integration sites. Research into virus-host interactions that underlie HIV-1 integration targeting has aided the development of a novel class of integrase inhibitors and may help to improve the safety of viral-based gene therapy vectors.
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Affiliation(s)
- Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, 450 Brookline Avenue, CLS-1010, Boston, MA, 02215, USA.
- Department of Medicine, Harvard Medical School, A-111, 25 Shattuck Street, Boston, MA, 02115, USA.
| | - Parmit K Singh
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, 450 Brookline Avenue, CLS-1010, Boston, MA, 02215, USA
- Department of Medicine, Harvard Medical School, A-111, 25 Shattuck Street, Boston, MA, 02115, USA
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Bieniasz PD, Kutluay SB. CLIP-related methodologies and their application to retrovirology. Retrovirology 2018; 15:35. [PMID: 29716635 PMCID: PMC5930818 DOI: 10.1186/s12977-018-0417-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 04/17/2018] [Indexed: 01/28/2023] Open
Abstract
Virtually every step of HIV-1 replication and numerous cellular antiviral defense mechanisms are regulated by the binding of a viral or cellular RNA-binding protein (RBP) to distinct sequence or structural elements on HIV-1 RNAs. Until recently, these protein-RNA interactions were studied largely by in vitro binding assays complemented with genetics approaches. However, these methods are highly limited in the identification of the relevant targets of RBPs in physiologically relevant settings. Development of crosslinking-immunoprecipitation sequencing (CLIP) methodology has revolutionized the analysis of protein-nucleic acid complexes. CLIP combines immunoprecipitation of covalently crosslinked protein-RNA complexes with high-throughput sequencing, providing a global account of RNA sequences bound by a RBP of interest in cells (or virions) at near-nucleotide resolution. Numerous variants of the CLIP protocol have recently been developed, some with major improvements over the original. Herein, we briefly review these methodologies and give examples of how CLIP has been successfully applied to retrovirology research.
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Affiliation(s)
- Paul D. Bieniasz
- Howard Hughes Medical Institute and Laboratory of Retrovirology, The Rockefeller University, New York, NY 10065 USA
| | - Sebla B. Kutluay
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110 USA
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24
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Bonnard D, Le Rouzic E, Eiler S, Amadori C, Orlov I, Bruneau JM, Brias J, Barbion J, Chevreuil F, Spehner D, Chasset S, Ledoussal B, Moreau F, Saïb A, Klaholz BP, Emiliani S, Ruff M, Zamborlini A, Benarous R. Structure-function analyses unravel distinct effects of allosteric inhibitors of HIV-1 integrase on viral maturation and integration. J Biol Chem 2018; 293:6172-6186. [PMID: 29507092 DOI: 10.1074/jbc.m117.816793] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 02/13/2018] [Indexed: 11/06/2022] Open
Abstract
Recently, a new class of HIV-1 integrase (IN) inhibitors with a dual mode of action, called IN-LEDGF/p75 allosteric inhibitors (INLAIs), was described. Designed to interfere with the IN-LEDGF/p75 interaction during viral integration, unexpectedly, their major impact was on virus maturation. This activity has been linked to induction of aberrant IN multimerization, whereas inhibition of the IN-LEDGF/p75 interaction accounts for weaker antiretroviral effect at integration. Because these dual activities result from INLAI binding to IN at a single binding site, we expected that these activities co-evolved together, driven by the affinity for IN. Using an original INLAI, MUT-A, and its activity on an Ala-125 (A125) IN variant, we found that these two activities on A125-IN can be fully dissociated: MUT-A-induced IN multimerization and the formation of eccentric condensates in viral particles, which are responsible for inhibition of virus maturation, were lost, whereas inhibition of the IN-LEDGF/p75 interaction and consequently integration was fully retained. Hence, the mere binding of INLAI to A125 IN is insufficient to promote the conformational changes of IN required for aberrant multimerization. By analyzing the X-ray structures of MUT-A bound to the IN catalytic core domain (CCD) with or without the Ala-125 polymorphism, we discovered that the loss of IN multimerization is due to stabilization of the A125-IN variant CCD dimer, highlighting the importance of the CCD dimerization energy for IN multimerization. Our study reveals that affinity for the LEDGF/p75-binding pocket is not sufficient to induce INLAI-dependent IN multimerization and the associated inhibition of viral maturation.
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Affiliation(s)
- Damien Bonnard
- From Biodim Mutabilis, 93230 Romainville, .,Inserm U944, CNRS UMR 7212, Université Paris Diderot, Conservatoire National des Arts et Métiers, 75010 Paris
| | | | - Sylvia Eiler
- the Centre for Integrative Biology, IGBMC, Inserm, CNRS, Université de Strasbourg, 67404 Illkirch, and
| | - Céline Amadori
- From Biodim Mutabilis, 93230 Romainville.,the Institut Cochin, Inserm U1016, 75014 Paris, France
| | - Igor Orlov
- the Centre for Integrative Biology, IGBMC, Inserm, CNRS, Université de Strasbourg, 67404 Illkirch, and
| | | | | | | | | | - Danièle Spehner
- the Centre for Integrative Biology, IGBMC, Inserm, CNRS, Université de Strasbourg, 67404 Illkirch, and
| | | | | | | | - Ali Saïb
- Inserm U944, CNRS UMR 7212, Université Paris Diderot, Conservatoire National des Arts et Métiers, 75010 Paris
| | - Bruno P Klaholz
- the Centre for Integrative Biology, IGBMC, Inserm, CNRS, Université de Strasbourg, 67404 Illkirch, and
| | | | - Marc Ruff
- the Centre for Integrative Biology, IGBMC, Inserm, CNRS, Université de Strasbourg, 67404 Illkirch, and
| | - Alessia Zamborlini
- Inserm U944, CNRS UMR 7212, Université Paris Diderot, Conservatoire National des Arts et Métiers, 75010 Paris,
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