1
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Song N, Zheng W, Song B, Zheng J. Allosteric Regulation and Inhibition of Coronavirus 3CLpro Revealed by HDX-MS. Chembiochem 2024; 25:e202400001. [PMID: 38720172 DOI: 10.1002/cbic.202400001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 05/03/2024] [Indexed: 07/03/2024]
Abstract
Coronavirus (CoV) infections have caused contagious and fatal respiratory diseases in humans worldwide. CoV 3-chymotrypsin-like proteases (3CLpro or Mpro) play an important role in viral maturation, and maintenance of their dimeric conformation is crucial for viral activity. Therefore, allosterically regulated dimerization of 3CLpro can be employed as a drug development target. Here, we investigated the allosteric regulatory mechanism of 3CLpro dimerization by using hydrogen/deuterium exchange coupled with mass spectrometry (HDX-MS) technology. We found that the FLAG tag directly coupled to the N-finger of 3CLpro significantly increased HDX kinetics at the dimer interface, and 3CLpro transformed from a dimer to a monomer. The 3CLpro mutants of SARS-CoV-2, which are monomeric, also exhibited increased deuterium exchange. Binding of the allosteric inhibitor Gastrodenol to most betacoronavirus 3CLpros led to increased allosteric deuterium exchange, resulting in the monomeric conformation of the CoV 3CLpro upon binding. Molecular dynamics (MD) simulation analysis further indicated the molecular mechanism of action of Gastrodenol on CoV 3CLpro: binding of Gastrodenol to SARS-CoV-2 3CLpro destroyed the hydrogen bond in the dimer interface. These results suggest that Gastrodenol may be a potential broad-spectrum anti-betacoronavirus drug.
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Affiliation(s)
- Ning Song
- Immunological Disease Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Rd, 201203, Shanghai, PR China
- University of Chinese Academy of Sciences, No. 1 Yanqihu East Rd, Huairou District, 101408, Beijing, PR China
| | - Wen Zheng
- CADD computer-aided protein Design Simulator, Hubei Yuanda Biotechnology Co., Ltd., Building B6, Optics Valley Biological City, Hongshan District, 430000, Wuhan, Hubei, PR China
| | - Bin Song
- Shanghai Institute of Virology, Shanghai Jiao Tong University School of Medicine, 227 South Chongqing Road, 200025, Shanghai, PR China
| | - Jie Zheng
- Immunological Disease Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Rd, 201203, Shanghai, PR China
- University of Chinese Academy of Sciences, No. 1 Yanqihu East Rd, Huairou District, 101408, Beijing, PR China
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2
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Solotchi M, Patel SS. Proofreading mechanisms of the innate immune receptor RIG-I: distinguishing self and viral RNA. Biochem Soc Trans 2024; 52:1131-1148. [PMID: 38884803 DOI: 10.1042/bst20230724] [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: 04/13/2024] [Revised: 06/02/2024] [Accepted: 06/04/2024] [Indexed: 06/18/2024]
Abstract
The RIG-I-like receptors (RLRs), comprising retinoic acid-inducible gene I (RIG-I), melanoma differentiation-associated gene 5 (MDA5), and laboratory of genetics and physiology 2 (LGP2), are pattern recognition receptors belonging to the DExD/H-box RNA helicase family of proteins. RLRs detect viral RNAs in the cytoplasm and respond by initiating a robust antiviral response that up-regulates interferon and cytokine production. RIG-I and MDA5 complement each other by recognizing different RNA features, and LGP2 regulates their activation. RIG-I's multilayered RNA recognition and proofreading mechanisms ensure accurate viral RNA detection while averting harmful responses to host RNAs. RIG-I's C-terminal domain targets 5'-triphosphate double-stranded RNA (dsRNA) blunt ends, while an intrinsic gating mechanism prevents the helicase domains from non-specifically engaging with host RNAs. The ATPase and RNA translocation activity of RIG-I adds another layer of selectivity by minimizing the lifetime of RIG-I on non-specific RNAs, preventing off-target activation. The versatility of RIG-I's ATPase function also amplifies downstream signaling by enhancing the signaling domain (CARDs) exposure on 5'-triphosphate dsRNA and promoting oligomerization. In this review, we offer an in-depth understanding of the mechanisms RIG-I uses to facilitate viral RNA sensing and regulate downstream activation of the immune system.
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Affiliation(s)
- Mihai Solotchi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, U.S.A
- Graduate School of Biomedical Sciences, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, U.S.A
| | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, U.S.A
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3
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Yoneyama M, Kato H, Fujita T. Physiological functions of RIG-I-like receptors. Immunity 2024; 57:731-751. [PMID: 38599168 DOI: 10.1016/j.immuni.2024.03.003] [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: 01/20/2024] [Revised: 02/19/2024] [Accepted: 03/04/2024] [Indexed: 04/12/2024]
Abstract
RIG-I-like receptors (RLRs) are crucial for pathogen detection and triggering immune responses and have immense physiological importance. In this review, we first summarize the interferon system and innate immunity, which constitute primary and secondary responses. Next, the molecular structure of RLRs and the mechanism of sensing non-self RNA are described. Usually, self RNA is refractory to the RLR; however, there are underlying host mechanisms that prevent immune reactions. Studies have revealed that the regulatory mechanisms of RLRs involve covalent molecular modifications, association with regulatory factors, and subcellular localization. Viruses have evolved to acquire antagonistic RLR functions to escape the host immune reactions. Finally, the pathologies caused by the malfunction of RLR signaling are described.
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Affiliation(s)
- Mitsutoshi Yoneyama
- Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba, Japan; Division of Pandemic and Post-disaster Infectious Diseases, Research Institute of Disaster Medicine, Chiba University, Chiba, Japan
| | - Hiroki Kato
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Takashi Fujita
- Institute of Cardiovascular Immunology, Medical Faculty, University Hospital Bonn, University of Bonn, Bonn, Germany; Laboratory of Regulatory Information, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan.
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4
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Sikorska J, Hou Y, Chiurazzi P, Siu T, Baltus GA, Sheth P, McLaren D, Truong Q, Parish C, Wyss D. Characterization of RNA driven structural changes in full length RIG-I leading to its agonism or antagonism. Nucleic Acids Res 2023; 51:9356-9368. [PMID: 37486777 PMCID: PMC10516622 DOI: 10.1093/nar/gkad606] [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] [Received: 11/27/2022] [Revised: 06/30/2023] [Accepted: 07/20/2023] [Indexed: 07/26/2023] Open
Abstract
RIG-I (retinoic acid inducible gene-I) can sense subtle differences between endogenous and viral RNA in the cytoplasm, triggering an anti-viral immune response through induction of type I interferons (IFN) and other inflammatory mediators. Multiple crystal and cryo-EM structures of RIG-I suggested a mechanism in which the C-terminal domain (CTD) is responsible for the recognition of viral RNA with a 5'-triphoshate modification, while the CARD domains serve as a trigger for downstream signaling, leading to the induction of type I IFN. However, to date contradicting conclusions have been reached around the role of ATP in the mechanism of the CARD domains ejection from RIG-I's autoinhibited state. Here we present an application of NMR spectroscopy to investigate changes induced by the binding of 5'-triphosphate and 5'-OH dsRNA, both in the presence and absence of nucleotides, to full length RIG-I with all its methionine residues selectively labeled (Met-[ϵ-13CH3]). With this approach we were able to identify residues on the CTD, helicase domain, and CARDs that served as probes to sense RNA-induced conformational changes in those respective regions. Our results were analyzed in the context of either agonistic or antagonistic RNAs, by and large supporting a mechanism proposed by the Pyle Lab in which CARD release is primarily dependent on the RNA binding event.
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Affiliation(s)
| | - Yan Hou
- Merck & Co., Inc., Rahway, NJ, USA
| | | | - Tony Siu
- Merck & Co., Inc., Rahway, NJ, USA
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5
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Zheng J, Shi W, Yang Z, Chen J, Qi A, Yang Y, Deng Y, Yang D, Song N, Song B, Luo D. RIG-I-like receptors: Molecular mechanism of activation and signaling. Adv Immunol 2023; 158:1-74. [PMID: 37453753 DOI: 10.1016/bs.ai.2023.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
During RNA viral infection, RIG-I-like receptors (RLRs) recognize the intracellular pathogenic RNA species derived from viral replication and activate antiviral innate immune response by stimulating type 1 interferon expression. Three RLR members, namely, RIG-I, MDA5, and LGP2 are homologous and belong to a subgroup of superfamily 2 Helicase/ATPase that is preferably activated by double-stranded RNA. RLRs are significantly different in gene architecture, RNA ligand preference, activation, and molecular functions. As switchable macromolecular sensors, RLRs' activities are tightly regulated by RNA ligands, ATP, posttranslational modifications, and cellular cofactors. We provide a comprehensive review of the structure and function of the RLRs and summarize the molecular understanding of sensing and signaling events during the RLR activation process. The key roles RLR signaling play in both anti-infection and immune disease conditions highlight the therapeutic potential in targeting this important molecular pathway.
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Affiliation(s)
- Jie Zheng
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China; Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
| | - Wenjia Shi
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ziqun Yang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Jin Chen
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ao Qi
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China; Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yulin Yang
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China; Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ying Deng
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Dongyuan Yang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Ning Song
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Bin Song
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore.
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6
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Lei Y, Fei P, Song B, Shi W, Luo C, Luo D, Li D, Chen W, Zheng J. A loosened gating mechanism of RIG-I leads to autoimmune disorders. Nucleic Acids Res 2022; 50:5850-5863. [PMID: 35580046 PMCID: PMC9177982 DOI: 10.1093/nar/gkac361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/22/2022] [Accepted: 04/27/2022] [Indexed: 11/12/2022] Open
Abstract
DDX58 encodes RIG-I, a cytosolic RNA sensor that ensures immune surveillance of nonself RNAs. Individuals with RIG-IE510V and RIG-IQ517H mutations have increased susceptibility to Singleton-Merten syndrome (SMS) defects, resulting in tissue-specific (mild) and classic (severe) phenotypes. The coupling between RNA recognition and conformational changes is central to RIG-I RNA proofreading, but the molecular determinants leading to dissociated disease phenotypes remain unknown. Herein, we employed hydrogen/deuterium exchange mass spectrometry (HDX-MS) and single molecule magnetic tweezers (MT) to precisely examine how subtle conformational changes in the helicase insertion domain (HEL2i) promote impaired ATPase and erroneous RNA proofreading activities. We showed that the mutations cause a loosened latch-gate engagement in apo RIG-I, which in turn gradually dampens its self RNA (Cap2 moiety:m7G cap and N1-2-2′-O-methylation RNA) proofreading ability, leading to increased immunopathy. These results reveal HEL2i as a unique checkpoint directing two specialized functions, i.e. stabilizing the CARD2-HEL2i interface and gating the helicase from incoming self RNAs; thus, these findings add new insights into the role of HEL2i in the control of antiviral innate immunity and autoimmunity diseases.
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Affiliation(s)
- Yixuan Lei
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.,The Drug Research Center of Immunological Diseases, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Panyu Fei
- Department of Cell Biology and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,School of Mechanical Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China
| | - Bin Song
- The Drug Research Center of Immunological Diseases, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Wenjia Shi
- The Drug Research Center of Immunological Diseases, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, Jiangsu, China
| | - Cheng Luo
- Department of Cell Biology and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,The Chemical Biology Center, Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, Zhejiang, China
| | - Dahai Luo
- Lee Kong Chian School of Medicine, NTU Institute of Structural Biology, School of Biological Sciences, Nanyang Technological University, 636921, Singapore
| | - Dan Li
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Wei Chen
- Department of Cell Biology and Department of Cardiology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou 311121, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the MOE Frontier Science Center for Brain Science & Brain-Machine Integration, State Key Laboratory for Modern Optical Instrumentation Key Laboratory for Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Jie Zheng
- The Drug Research Center of Immunological Diseases, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, Jiangsu, China.,School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, Zhejiang, China
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7
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Schweibenz BD, Devarkar SC, Solotchi M, Craig C, Zheng J, Pascal BD, Gokhale S, Xie P, Griffin PR, Patel SS. The intrinsically disordered CARDs-Helicase linker in RIG-I is a molecular gate for RNA proofreading. EMBO J 2022; 41:e109782. [PMID: 35437807 PMCID: PMC9108607 DOI: 10.15252/embj.2021109782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 03/28/2022] [Accepted: 04/04/2022] [Indexed: 01/22/2023] Open
Abstract
The innate immune receptor RIG-I provides a first line of defense against viral infections. Viral RNAs are recognized by RIG-I's C-terminal domain (CTD), but the RNA must engage the helicase domain to release the signaling CARD (Caspase Activation and Recruitment Domain) domains from their autoinhibitory CARD2:Hel2i interactions. Because the helicase itself lacks RNA specificity, mechanisms to proofread RNAs entering the helicase domain must exist. Although such mechanisms would be crucial in preventing aberrant immune responses by non-specific RNAs, they remain largely uncharacterized to date. This study reveals a previously unknown proofreading mechanism through which RIG-I ensures that the helicase engages RNAs explicitly recognized by the CTD. A crucial part of this mechanism involves the intrinsically disordered CARDs-Helicase Linker (CHL), which connects the CARDs to the helicase subdomain Hel1. CHL uses its negatively charged regions to antagonize incoming RNAs electrostatically. In addition to this RNA gating function, CHL is essential for stabilization of the CARD2:Hel2i interface. Overall, we uncover that the CHL and CARD2:Hel2i interface work together to establish a tunable gating mechanism that allows CTD-chosen RNAs to bind the helicase domain, while at the same time blocking non-specific RNAs. These findings also indicate that CHL could represent a novel target for RIG-I-based therapeutics.
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Affiliation(s)
- Brandon D Schweibenz
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.,Graduate Program in Biochemistry, Rutgers University, Piscataway, NJ, USA
| | - Swapnil C Devarkar
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.,Graduate Program in Biochemistry, Rutgers University, Piscataway, NJ, USA
| | - Mihai Solotchi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.,Cell and Development Biology, Rutgers University, Piscataway, NJ, USA
| | - Candice Craig
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.,Graduate Program in Biochemistry, Rutgers University, Piscataway, NJ, USA
| | - Jie Zheng
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, USA
| | - Bruce D Pascal
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, USA
| | - Samantha Gokhale
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, USA.,Cellular and Molecular Pharmacology, Rutgers University, Piscataway, NJ, USA
| | - Ping Xie
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, USA.,Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
| | - Patrick R Griffin
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, USA.,Department of Integrative Structural and Computational Biology, Jupiter, FL, USA
| | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA.,Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
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8
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Song B, Chen Y, Liu X, Yuan F, Tan EYJ, Lei Y, Song N, Han Y, Pascal BD, Griffin PR, Luo C, Wu B, Luo D, Zheng J. Ordered assembly of the cytosolic RNA-sensing MDA5-MAVS signaling complex via binding to unanchored K63-linked poly-ubiquitin chains. Immunity 2021; 54:2218-2230.e5. [PMID: 34644557 DOI: 10.1016/j.immuni.2021.09.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 05/05/2021] [Accepted: 09/14/2021] [Indexed: 11/15/2022]
Abstract
The RNA sensor MDA5 recruits the signaling adaptor MAVS to initiate type I interferon signaling and downstream antiviral responses, a process that requires K63-linked polyubiquitin chains. Here, we examined the mechanisms whereby K63-polyUb chain regulate MDA5 activation. Only long unanchored K63-polyUbn (n ≥ 8) could mediate tetramerization of the caspase activation and recruitment domains of MDA5 (MDA5CARDs). Cryoelectron microscopy structures of a polyUb13-bound MDA5CARDs tetramer and a polyUb11-bound MDA5CARDs-MAVSCARD assembly revealed a tower-like formation, wherein eight Ubs tethered along the outer rim of the helical shell, bridging MDA5CARDs and MAVSCARD tetramers into proximity. ATP binding and hydrolysis promoted the stabilization of RNA-bound MDA5 prior to MAVS activation via allosteric effects on CARDs-polyUb complex. Abundant ATP prevented basal activation of apo MDA5. Our findings reveal the ordered assembly of a MDA5 signaling complex competent to recruit and activate MAVS and highlight differences with RIG-I in terms of CARD orientation and Ub sensing that suggest different abilities to induce antiviral responses.
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Affiliation(s)
- Bin Song
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yun Chen
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xin Liu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Fei Yuan
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Eddie Yong Jun Tan
- NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive, Singapore 636921, Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 636921, Singapore
| | - Yixuan Lei
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Ning Song
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yinqi Han
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | | | - Patrick R Griffin
- The Scripps Research Institute, Department of Molecular Medicine, Jupiter, FL 33458, USA
| | - Cheng Luo
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China; The Center for Chemical Biology, Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Bin Wu
- NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive, Singapore 636921, Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 636921, Singapore
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, EMB 03-07, 59 Nanyang Drive, Singapore 636921, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive, Singapore 636921, Singapore; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 636921, Singapore
| | - Jie Zheng
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China.
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9
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Li K, Zheng J, Wirawan M, Trinh NM, Fedorova O, Griffin PR, Pyle AM, Luo D. Insights into the structure and RNA-binding specificity of Caenorhabditis elegans Dicer-related helicase 3 (DRH-3). Nucleic Acids Res 2021; 49:9978-9991. [PMID: 34403472 PMCID: PMC8464030 DOI: 10.1093/nar/gkab712] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/31/2021] [Accepted: 08/03/2021] [Indexed: 12/17/2022] Open
Abstract
DRH-3 is critically involved in germline development and RNA interference (RNAi) facilitated chromosome segregation via the 22G-siRNA pathway in Caenorhabditis elegans. DRH-3 has similar domain architecture to RIG-I-like receptors (RLRs) and belongs to the RIG-I-like RNA helicase family. The molecular understanding of DRH-3 and its function in endogenous RNAi pathways remains elusive. In this study, we solved the crystal structures of the DRH-3 N-terminal domain (NTD) and the C-terminal domains (CTDs) in complex with 5'-triphosphorylated RNAs. The NTD of DRH-3 adopts a distinct fold of tandem caspase activation and recruitment domains (CARDs) structurally similar to the CARDs of RIG-I and MDA5, suggesting a signaling function in the endogenous RNAi biogenesis. The CTD preferentially recognizes 5'-triphosphorylated double-stranded RNAs bearing the typical features of secondary siRNA transcripts. The full-length DRH-3 displays unique structural dynamics upon binding to RNA duplexes that differ from RIG-I or MDA5. These features of DRH-3 showcase the evolutionary divergence of the Dicer and RLR family of helicases.
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Affiliation(s)
- Kuohan Li
- Lee Kong Chian School of Medicine, Nanyang Technological University, EMB 03-07, 59 Nanyang Drive 636921, Singapore.,School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive 637551, Singapore.,NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive 636921, Singapore
| | - Jie Zheng
- The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Melissa Wirawan
- Lee Kong Chian School of Medicine, Nanyang Technological University, EMB 03-07, 59 Nanyang Drive 636921, Singapore.,NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive 636921, Singapore
| | - Nguyen Mai Trinh
- Lee Kong Chian School of Medicine, Nanyang Technological University, EMB 03-07, 59 Nanyang Drive 636921, Singapore.,NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive 636921, Singapore
| | - Olga Fedorova
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA.,Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | | | - Anna M Pyle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA.,Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, EMB 03-07, 59 Nanyang Drive 636921, Singapore.,School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive 637551, Singapore.,NTU Institute of Structural Biology, Nanyang Technological University, EMB 06-01, 59 Nanyang Drive 636921, Singapore
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10
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Thoresen D, Wang W, Galls D, Guo R, Xu L, Pyle AM. The molecular mechanism of RIG-I activation and signaling. Immunol Rev 2021; 304:154-168. [PMID: 34514601 PMCID: PMC9293153 DOI: 10.1111/imr.13022] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/10/2021] [Accepted: 08/17/2021] [Indexed: 12/25/2022]
Abstract
RIG‐I is our first line of defense against RNA viruses, serving as a pattern recognition receptor that identifies molecular features common among dsRNA and ssRNA viral pathogens. RIG‐I is maintained in an inactive conformation as it samples the cellular space for pathogenic RNAs. Upon encounter with the triphosphorylated terminus of blunt‐ended viral RNA duplexes, the receptor changes conformation and releases a pair of signaling domains (CARDs) that are selectively modified and interact with an adapter protein (MAVS), thereby triggering a signaling cascade that stimulates transcription of interferons. Here, we describe the structural determinants for specific RIG‐I activation by viral RNA, and we describe the strategies by which RIG‐I remains inactivated in the presence of host RNAs. From the initial RNA triggering event to the final stages of interferon expression, we describe the experimental evidence underpinning our working knowledge of RIG‐I signaling. We draw parallels with behavior of related proteins MDA5 and LGP2, describing evolutionary implications of their collective surveillance of the cell. We conclude by describing the cell biology and immunological investigations that will be needed to accurately describe the role of RIG‐I in innate immunity and to provide the necessary foundation for pharmacological manipulation of this important receptor.
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Affiliation(s)
- Daniel Thoresen
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Wenshuai Wang
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Drew Galls
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Rong Guo
- Chemistry, Yale University, New Haven, CT, USA
| | - Ling Xu
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Anna Marie Pyle
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.,Chemistry, Yale University, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
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11
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Perez JJ. Exploiting Knowledge on Structure-Activity Relationships for Designing Peptidomimetics of Endogenous Peptides. Biomedicines 2021; 9:651. [PMID: 34200402 PMCID: PMC8229937 DOI: 10.3390/biomedicines9060651] [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: 05/06/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 12/01/2022] Open
Abstract
Endogenous peptides are important mediators in cell communication, being consequently involved in many physiological processes. Their use as therapeutic agents is limited due to their poor pharmacokinetic profile. To circumvent this drawback, alternative diverse molecules based on the stereochemical features that confer their activity can be synthesized, using them as guidance; from peptide surrogates provided with a better pharmacokinetic profile, to small molecule peptidomimetics, through cyclic peptides. The design process requires a competent use of the structure-activity results available on individual peptides. Specifically, it requires synthesis and analysis of the activity of diverse analogs, biophysical information and computational work. In the present work, we show a general framework of the process and show its application to two specific examples: the design of selective AT1 antagonists of angiotensin and the design of selective B2 antagonists of bradykinin.
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Affiliation(s)
- Juan J Perez
- Department of Chemical Engineering, Universitat Politecnica de Catalunya, 08028 Barcelona, Spain
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12
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Tuske S, Zheng J, Olson ED, Ruiz FX, Pascal BD, Hoang A, Bauman JD, Das K, DeStefano JJ, Musier-Forsyth K, Griffin PR, Arnold E. Integrative structural biology studies of HIV-1 reverse transcriptase binding to a high-affinity DNA aptamer. Curr Res Struct Biol 2020; 2:116-129. [PMID: 33870216 PMCID: PMC8052095 DOI: 10.1016/j.crstbi.2020.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 06/03/2020] [Accepted: 06/19/2020] [Indexed: 02/07/2023] Open
Abstract
The high-resolution crystal structure of HIV-1 reverse transcriptase (RT) bound to a 38-mer DNA hairpin aptamer with low pM affinity was previously described. The high-affinity binding aptamer contained 2'-O-methyl modifications and a seven base-pair GC-rich tract and the structure of the RT-aptamer complex revealed specific contacts between RT and the template strand of the aptamer. Similar to all crystal structures of RT bound to nucleic acid template-primers, the aptamer bound RT with a bend in the duplex DNA. To understand the structural basis for the ultra-high-affinity aptamer binding, an integrative structural biology approach was used. Hydrogen-deuterium exchange coupled to liquid chromatography-mass spectrometry (HDX-MS) was used to examine the structural dynamics of RT alone and in the presence of the DNA aptamer. RT was selectively labeled with 15N to unambiguously identify peptides from each subunit. HDX of unliganded RT shows a mostly stable core. The p66 fingers and thumb subdomains, and the RNase H domain are relatively dynamic. HDX indicates that both the aptamer and a scrambled version significantly stabilize regions of RT that are dynamic in the absence of DNA. No substantial differences in RT dynamics are observed between aptamer and scrambled aptamer binding, despite a large difference in binding affinity. Small-angle X-ray scattering and circular dichroism spectroscopy were used to investigate the aptamer conformation in solution and revealed a pre-bent DNA that possesses both A- and B-form helical character. Both the 2'-O-methyl modifications and the GC tract appear to contribute to an energetically favorable conformation for binding to RT that contributes to the aptamer's ultra-high affinity for RT. The X-ray structure of RT with an RNA/DNA version of the aptamer at 2.8 Å resolution revealed a potential role of the hairpin positioning in affinity. Together, the data suggest that both the 2'-O-methyl modifications and the GC tract contribute to an energetically favorable conformation for high-affinity binding to RT.
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Affiliation(s)
- Steve Tuske
- Center for Advanced Biotechnology and Medicine, And Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Jie Zheng
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Erik D. Olson
- Department of Chemistry and Biochemistry, Center for RNA Biology, And Center for Retrovirus Research, The Ohio State University, Columbus, OH, 43210, USA
| | - Francesc X. Ruiz
- Center for Advanced Biotechnology and Medicine, And Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Bruce D. Pascal
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Anthony Hoang
- Center for Advanced Biotechnology and Medicine, And Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Joseph D. Bauman
- Center for Advanced Biotechnology and Medicine, And Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Kalyan Das
- Center for Advanced Biotechnology and Medicine, And Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Jeffrey J. DeStefano
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, College Park, MD, 20740, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for RNA Biology, And Center for Retrovirus Research, The Ohio State University, Columbus, OH, 43210, USA
| | - Patrick R. Griffin
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Eddy Arnold
- Center for Advanced Biotechnology and Medicine, And Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
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13
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Hausmann S, Geiser J, Vadas O, Ducret V, Perron K, Valentini M. Auxiliary domains of the HrpB bacterial DExH-box helicase shape its RNA preferences. RNA Biol 2020; 17:637-650. [PMID: 32050838 PMCID: PMC7237152 DOI: 10.1080/15476286.2020.1720376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
RNA helicases are fundamental players in RNA metabolism: they remodel RNA secondary structures and arrange ribonucleoprotein complexes. While DExH-box RNA helicases function in ribosome biogenesis and splicing in eukaryotes, information is scarce about bacterial homologs. HrpB is the only bacterial DExH-box protein whose structure is solved. Besides the catalytic core, HrpB possesses three accessory domains, conserved in all DExH-box helicases, plus a unique C-terminal extension (CTE). The function of these auxiliary domains remains unknown. Here, we characterize genetically and biochemically Pseudomonas aeruginosa HrpB homolog. We reveal that the auxiliary domains shape HrpB RNA preferences, affecting RNA species recognition and catalytic activity. We show that, among several types of RNAs, the single-stranded poly(A) and the highly structured MS2 RNA strongly stimulate HrpB ATPase activity. In addition, deleting the CTE affects only stimulation by structured RNAs like MS2 and rRNAs, while deletion of accessory domains results in gain of poly(U)-dependent activity. Finally, using hydrogen-deuterium exchange, we dissect the molecular details of HrpB interaction with poly(A) and MS2 RNAs. The catalytic core interacts with both RNAs, triggering a conformational change that reorients HrpB. Regions within the accessory domains and CTE are, instead, specifically responsive to MS2. Altogether, we demonstrate that in bacteria, like in eukaryotes, DExH-box helicase auxiliary domains are indispensable for RNA handling.
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Affiliation(s)
- Stéphane Hausmann
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Johan Geiser
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Oscar Vadas
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Protein Production Platform, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Verena Ducret
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Karl Perron
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Martina Valentini
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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14
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Ren X, Linehan MM, Iwasaki A, Pyle AM. RIG-I Recognition of RNA Targets: The Influence of Terminal Base Pair Sequence and Overhangs on Affinity and Signaling. Cell Rep 2019; 29:3807-3815.e3. [PMID: 31851914 DOI: 10.1016/j.celrep.2019.11.052] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 09/24/2019] [Accepted: 11/13/2019] [Indexed: 12/25/2022] Open
Abstract
Within the complex environment of the human cell, the RIG-I innate immune receptor must detect the presence of double-stranded viral RNA molecules and differentiate them from a diversity of host RNA molecules. In an ongoing effort to understand the molecular basis for RIG-I target specificity, here, we evaluate the ability of this sensor to respond to triphosphorylated, double-stranded RNA molecules that contain all possible terminal base pairs and common mismatches. In addition, we test the response to duplexes with various types of 5' and 3' overhangs. We conducted quantitative measurements of RNA ligand affinity, then tested RNA variants for their ability to stimulate the RIG-I-dependent interferon response in cells and in whole animals. The resulting data provide insights into the design of RNA therapeutics that prevent RIG-I activation, and they provide valuable insights into the mechanisms of evasion by deadly pathogens such as the Ebola and Marburg viruses.
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Affiliation(s)
- Xiaoming Ren
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Melissa M Linehan
- Department of Immunobiology, Yale University, New Haven, CT 06520, USA
| | - Akiko Iwasaki
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Immunobiology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Anna Marie Pyle
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA.
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15
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Yong HY, Zheng J, Ho VCY, Nguyen MT, Fink K, Griffin PR, Luo D. Structure-guided design of immunomodulatory RNAs specifically targeting the cytoplasmic viral RNA sensor RIG-I. FEBS Lett 2019; 593:3003-3014. [PMID: 31369683 DOI: 10.1002/1873-3468.13564] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/22/2019] [Accepted: 07/28/2019] [Indexed: 12/22/2022]
Abstract
The cytoplasmic immune sensor RIG-I detects viral RNA and initiates an antiviral immune response upon activation. It has become a potential target for vaccination and immunotherapies. To develop the smallest but potent immunomodulatory RNA (immRNAs) species, we performed structure-guided RNA design and used biochemical, structural, and cell-based methods to select and characterize the immRNAs. We demonstrated that inserting guanosine at position 9 to the 10mer RNA hairpin (3p10LG9) activates RIG-I more robustly than the parental RNA. 3p10LG9 interacts strongly with the RIG-I helicase-CTD RNA sensing module and disrupts the auto-inhibitory interaction between the HEL2i and CARDs domains. We further showed that 3p10LA9 has a stronger cellular activity than 3p10LG9. Collectively, purine insertion at position 9 of the immRNA species triggered more robust activation of RIG-1.
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Affiliation(s)
- Hui Yee Yong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore City, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore City, Singapore
| | - Jie Zheng
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, USA
| | - Victor Chin Yong Ho
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore City, Singapore
| | - Mai Trinh Nguyen
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore City, Singapore
| | - Katja Fink
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore City, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore City, Singapore
| | - Patrick R Griffin
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, USA
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore City, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore City, Singapore
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16
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Dickey TH, Song B, Pyle AM. RNA binding activates RIG-I by releasing an autorepressed signaling domain. SCIENCE ADVANCES 2019; 5:eaax3641. [PMID: 31616790 PMCID: PMC6774723 DOI: 10.1126/sciadv.aax3641] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
The retinoic acid-inducible gene I (RIG-I) innate immune receptor is an important immunotherapeutic target, but we lack approaches for monitoring the physical basis for its activation in vitro. This gap in our understanding has led to confusion about mechanisms of RIG-I activation and difficulty discovering agonists and antagonists. We therefore created a novel fluorescence resonance energy transfer-based method for measuring RIG-I activation in vitro using dual site-specific fluorescent labeling of the protein. This approach enables us to measure the conformational change that releases the signaling domain during the first step of RIG-I activation, making it possible to understand the role of stimulatory ligands. We have found that RNA alone is sufficient to eject the signaling domain, ejection is reversible, and adenosine triphosphate plays but a minor role in this process. These findings help explain RIG-I dysfunction in autoimmune disease, and they inform the design of therapeutics targeting RIG-I.
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Affiliation(s)
- T. H. Dickey
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - B. Song
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - A. M. Pyle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
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17
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Zheng J, Strutzenberg T, Pascal BD, Griffin PR. Protein dynamics and conformational changes explored by hydrogen/deuterium exchange mass spectrometry. Curr Opin Struct Biol 2019; 58:305-313. [DOI: 10.1016/j.sbi.2019.06.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 06/15/2019] [Accepted: 06/25/2019] [Indexed: 12/31/2022]
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18
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MS-Based Approaches Enable the Structural Characterization of Transcription Factor/DNA Response Element Complex. Biomolecules 2019; 9:biom9100535. [PMID: 31561554 PMCID: PMC6843354 DOI: 10.3390/biom9100535] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/18/2019] [Accepted: 09/24/2019] [Indexed: 02/06/2023] Open
Abstract
The limited information available on the structure of complexes involving transcription factors and cognate DNA response elements represents a major obstacle in the quest to understand their mechanism of action at the molecular level. We implemented a concerted structural proteomics approach, which combined hydrogen-deuterium exchange (HDX), quantitative protein-protein and protein-nucleic acid cross-linking (XL), and homology analysis, to model the structure of the complex between the full-length DNA binding domain (DBD) of Forkhead box protein O4 (FOXO4) and its DNA binding element (DBE). The results confirmed that FOXO4-DBD assumes the characteristic forkhead topology shared by these types of transcription factors, but its binding mode differs significantly from those of other members of the family. The results showed that the binding interaction stabilized regions that were rather flexible and disordered in the unbound form. Surprisingly, the conformational effects were not limited only to the interface between bound components, but extended also to distal regions that may be essential to recruiting additional factors to the transcription machinery. In addition to providing valuable new insights into the binding mechanism, this project provided an excellent evaluation of the merits of structural proteomics approaches in the investigation of systems that are not directly amenable to traditional high-resolution techniques.
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19
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Brisse M, Ly H. Comparative Structure and Function Analysis of the RIG-I-Like Receptors: RIG-I and MDA5. Front Immunol 2019; 10:1586. [PMID: 31379819 PMCID: PMC6652118 DOI: 10.3389/fimmu.2019.01586] [Citation(s) in RCA: 218] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 06/25/2019] [Indexed: 12/12/2022] Open
Abstract
RIG-I (Retinoic acid-inducible gene I) and MDA5 (Melanoma Differentiation-Associated protein 5), collectively known as the RIG-I-like receptors (RLRs), are key protein sensors of the pathogen-associated molecular patterns (PAMPs) in the form of viral double-stranded RNA (dsRNA) motifs to induce expression of type 1 interferons (IFN1) (IFNα and IFNβ) and other pro-inflammatory cytokines during the early stage of viral infection. While RIG-I and MDA5 share many genetic, structural and functional similarities, there is increasing evidence that they can have significantly different strategies to recognize different pathogens, PAMPs, and in different host species. This review article discusses the similarities and differences between RIG-I and MDA5 from multiple perspectives, including their structures, evolution and functional relationships with other cellular proteins, their differential mechanisms of distinguishing between host and viral dsRNAs and interactions with host and viral protein factors, and their immunogenic signaling. A comprehensive comparative analysis can help inform future studies of RIG-I and MDA5 in order to fully understand their functions in order to optimize potential therapeutic approaches targeting them.
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Affiliation(s)
- Morgan Brisse
- Biochemistry, Molecular Biology, and Biophysics Graduate Program, University of Minnesota, Twin Cities, St. Paul, MN, United States
- Department of Veterinary & Biomedical Sciences, University of Minnesota, Twin Cities, St. Paul, MN, United States
| | - Hinh Ly
- Department of Veterinary & Biomedical Sciences, University of Minnesota, Twin Cities, St. Paul, MN, United States
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20
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Kesy J, Patil KM, Kumar SR, Shu Z, Yong HY, Zimmermann L, Ong AAL, Toh DFK, Krishna MS, Yang L, Decout JL, Luo D, Prabakaran M, Chen G, Kierzek E. A Short Chemically Modified dsRNA-Binding PNA (dbPNA) Inhibits Influenza Viral Replication by Targeting Viral RNA Panhandle Structure. Bioconjug Chem 2019; 30:931-943. [PMID: 30721034 DOI: 10.1021/acs.bioconjchem.9b00039] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
RNAs play critical roles in diverse catalytic and regulatory biological processes and are emerging as important disease biomarkers and therapeutic targets. Thus, developing chemical compounds for targeting any desired RNA structures has great potential in biomedical applications. The viral and cellular RNA sequence and structure databases lay the groundwork for developing RNA-binding chemical ligands through the recognition of both RNA sequence and RNA structure. Influenza A virion consists of eight segments of negative-strand viral RNA (vRNA), all of which contain a highly conserved panhandle duplex structure formed between the first 13 nucleotides at the 5' end and the last 12 nucleotides at the 3' end. Here, we report our binding and cell culture anti-influenza assays of a short 10-mer chemically modified double-stranded RNA (dsRNA)-binding peptide nucleic acid (PNA) designed to bind to the panhandle duplex structure through novel major-groove PNA·RNA2 triplex formation. We demonstrated that incorporation of chemically modified PNA residues thio-pseudoisocytosine (L) and guanidine-modified 5-methyl cytosine (Q) previously developed by us facilitates the sequence-specific recognition of Watson-Crick G-C and C-G pairs, respectively, at physiologically relevant conditions. Significantly, the chemically modified dsRNA-binding PNA (dbPNA) shows selective binding to the dsRNA region in panhandle structure over a single-stranded RNA (ssRNA) and a dsDNA containing the same sequence. The panhandle structure is not accessible to traditional antisense DNA or RNA with a similar length. Conjugation of the dbPNA with an aminosugar neamine enhances the cellular uptake. We observed that 2-5 μM dbPNA-neamine conjugate results in a significant reduction of viral replication. In addition, the 10-mer dbPNA inhibits innate immune receptor RIG-I binding to panhandle structure and thus RIG-I ATPase activity. These findings would provide the foundation for developing novel dbPNAs for the detection of influenza viral RNAs and therapeutics with optimal antiviral and immunomodulatory activities.
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Affiliation(s)
- Julita Kesy
- Institute of Bioorganic Chemistry, Polish Academy of Sciences , Noskowskiego 12/14 , 61-704 Poznan , Poland
| | - Kiran M Patil
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , 637371 , Singapore
| | | | - Zhiyu Shu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , 637371 , Singapore
| | - Hui Yee Yong
- Lee Kong Chian School of Medicine , Nanyang Technological University , EMB 03-07, 59 Nanyang Drive , 636921 , Singapore.,NTU Institute of Structural Biology , Nanyang Technological University , EMB 06-01, 59 Nanyang Drive , 636921 , Singapore.,School of Biological Sciences , Nanyang Technological University , 60 Nanyang Drive , 636921 , Singapore
| | - Louis Zimmermann
- Département de Pharmacochimie Moléculaire , University Grenoble Alpes, CNRS, ICMG FR 2607, UMR 5063 , 470 Rue de la Chimie , F-38041 Grenoble , France
| | - Alan Ann Lerk Ong
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , 637371 , Singapore
| | - Desiree-Faye Kaixin Toh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , 637371 , Singapore
| | - Manchugondanahalli S Krishna
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , 637371 , Singapore
| | - Lixia Yang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , 637371 , Singapore
| | - Jean-Luc Decout
- Département de Pharmacochimie Moléculaire , University Grenoble Alpes, CNRS, ICMG FR 2607, UMR 5063 , 470 Rue de la Chimie , F-38041 Grenoble , France
| | - Dahai Luo
- Lee Kong Chian School of Medicine , Nanyang Technological University , EMB 03-07, 59 Nanyang Drive , 636921 , Singapore.,NTU Institute of Structural Biology , Nanyang Technological University , EMB 06-01, 59 Nanyang Drive , 636921 , Singapore
| | - Mookkan Prabakaran
- Temasek Life Science Laboratory, 1 Research Link , National University of Singapore , 117604 , Singapore
| | - Gang Chen
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences , Nanyang Technological University , 21 Nanyang Link , 637371 , Singapore
| | - Elzbieta Kierzek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences , Noskowskiego 12/14 , 61-704 Poznan , Poland
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21
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Kasumba DM, Grandvaux N. Therapeutic Targeting of RIG-I and MDA5 Might Not Lead to the Same Rome. Trends Pharmacol Sci 2019; 40:116-127. [PMID: 30606502 PMCID: PMC7112877 DOI: 10.1016/j.tips.2018.12.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/05/2018] [Accepted: 12/06/2018] [Indexed: 12/12/2022]
Abstract
RIG-I and MDA5 receptors are key sensors of pathogen-associated molecular pattern (PAMP)-containing viral RNA and transduce downstream signals to activate an antiviral and immunomodulatory response. Fifteen years of research have put them at the center of an ongoing hunt for novel pharmacological pan-antivirals, vaccine adjuvants, and antitumor strategies. Current knowledge testifies to the redundant, but also distinct, functions mediated by RIG-I and MDA5, opening opportunities for the use of specific and potent nucleic acid agonists. We critically discuss the evidence and remaining knowledge gaps that have an impact on the choice and design of optimal RNA ligands to achieve an appropriate immunostimulatory response, with limited adverse effects, for prophylactic and therapeutic interventions against viruses and cancer in humans.
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Affiliation(s)
- Dacquin M. Kasumba
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Nathalie Grandvaux
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada; Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
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22
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Applications of In-Cell NMR in Structural Biology and Drug Discovery. Int J Mol Sci 2019; 20:ijms20010139. [PMID: 30609728 PMCID: PMC6337603 DOI: 10.3390/ijms20010139] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/24/2018] [Accepted: 12/29/2018] [Indexed: 01/23/2023] Open
Abstract
In-cell nuclear magnetic resonance (NMR) is a method to provide the structural information of a target at an atomic level under physiological conditions and a full view of the conformational changes of a protein caused by ligand binding, post-translational modifications or protein⁻protein interactions in living cells. Previous in-cell NMR studies have focused on proteins that were overexpressed in bacterial cells and isotopically labeled proteins injected into oocytes of Xenopus laevis or delivered into human cells. Applications of in-cell NMR in probing protein modifications, conformational changes and ligand bindings have been carried out in mammalian cells by monitoring isotopically labeled proteins overexpressed in living cells. The available protocols and successful examples encourage wide applications of this technique in different fields such as drug discovery. Despite the challenges in this method, progress has been made in recent years. In this review, applications of in-cell NMR are summarized. The successful applications of this method in mammalian and bacterial cells make it feasible to play important roles in drug discovery, especially in the step of target engagement.
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23
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Zheng J, Wang C, Chang MR, Devarkar SC, Schweibenz B, Crynen GC, Garcia-Ordonez RD, Pascal BD, Novick SJ, Patel SS, Marcotrigiano J, Griffin PR. HDX-MS reveals dysregulated checkpoints that compromise discrimination against self RNA during RIG-I mediated autoimmunity. Nat Commun 2018; 9:5366. [PMID: 30560918 PMCID: PMC6299088 DOI: 10.1038/s41467-018-07780-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 11/28/2018] [Indexed: 01/25/2023] Open
Abstract
Retinoic acid inducible gene-I (RIG-I) ensures immune surveillance of viral RNAs bearing a 5'-triphosphate (5'ppp) moiety. Mutations in RIG-I (C268F and E373A) lead to impaired ATPase activity, thereby driving hyperactive signaling associated with autoimmune diseases. Here we report, using hydrogen/deuterium exchange, mechanistic models for dysregulated RIG-I proofreading that ultimately result in the improper recognition of cellular RNAs bearing 7-methylguanosine and N1-2'-O-methylation (Cap1) on the 5' end. Cap1-RNA compromises its ability to stabilize RIG-I helicase and blunts caspase activation and recruitment domains (CARD) partial opening by threefold. RIG-I H830A mutation restores Cap1-helicase engagement as well as CARDs partial opening event to a level comparable to that of 5'ppp. However, E373A RIG-I locks the receptor in an ATP-bound state, resulting in enhanced Cap1-helicase engagement and a sequential CARDs stimulation. C268F mutation renders a more tethered ring architecture and results in constitutive CARDs signaling in an ATP-independent manner.
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MESH Headings
- Adenosine Triphosphatases/metabolism
- Autoimmunity/genetics
- Caspase Activation and Recruitment Domain/immunology
- DEAD Box Protein 58/chemistry
- DEAD Box Protein 58/genetics
- DEAD Box Protein 58/immunology
- DEAD Box Protein 58/metabolism
- Deuterium Exchange Measurement/methods
- Gain of Function Mutation
- Guanosine/analogs & derivatives
- Guanosine/chemistry
- Guanosine/immunology
- Guanosine/metabolism
- Immunity, Innate/genetics
- Interferon-Induced Helicase, IFIH1/immunology
- Interferon-Induced Helicase, IFIH1/metabolism
- Mass Spectrometry/methods
- Methylation
- Models, Molecular
- Mutagenesis, Site-Directed
- Protein Binding/genetics
- Protein Binding/immunology
- RNA Caps/chemistry
- RNA Caps/immunology
- RNA Caps/metabolism
- RNA, Double-Stranded/chemistry
- RNA, Double-Stranded/immunology
- RNA, Double-Stranded/metabolism
- RNA, Viral/immunology
- Receptors, Immunologic
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Recombinant Proteins/metabolism
- Signal Transduction/genetics
- Signal Transduction/immunology
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Affiliation(s)
- Jie Zheng
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA.
| | - Chen Wang
- Structural Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Mi Ra Chang
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Swapnil C Devarkar
- Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA
| | - Brandon Schweibenz
- Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA
| | - Gogce C Crynen
- The Center for Computational Biology, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Ruben D Garcia-Ordonez
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Bruce D Pascal
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
- Omics Informatics LLC, Honolulu, HI 96813, USA
| | - Scott J Novick
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Smita S Patel
- Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, 08854, USA
| | - Joseph Marcotrigiano
- Structural Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Patrick R Griffin
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA.
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24
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Devarkar SC, Schweibenz B, Wang C, Marcotrigiano J, Patel SS. RIG-I Uses an ATPase-Powered Translocation-Throttling Mechanism for Kinetic Proofreading of RNAs and Oligomerization. Mol Cell 2018; 72:355-368.e4. [PMID: 30270105 PMCID: PMC6434538 DOI: 10.1016/j.molcel.2018.08.021] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/15/2018] [Accepted: 08/14/2018] [Indexed: 12/25/2022]
Abstract
RIG-I has a remarkable ability to specifically select viral 5'ppp dsRNAs for activation from a pool of cytosolic self-RNAs. The ATPase activity of RIG-I plays a role in RNA discrimination and activation, but the underlying mechanism was unclear. Using transient-state kinetics, we elucidated the ATPase-driven "kinetic proofreading" mechanism of RIG-I activation and RNA discrimination, akin to DNA polymerases, ribosomes, and T cell receptors. Even in the autoinhibited state of RIG-I, the C-terminal domain kinetically discriminates against self-RNAs by fast off rates. ATP binding facilitates dsRNA engagement but, interestingly, makes RIG-I promiscuous, explaining the constitutive signaling by Singleton-Merten syndrome-linked mutants that bind ATP without hydrolysis. ATP hydrolysis dissociates self-RNAs faster than 5'ppp dsRNA but, more importantly, drives RIG-I oligomerization through translocation, which we show to be regulated by helicase motif IVa. RIG-I translocates directionally from the dsRNA end into the stem region, and the 5'ppp end "throttles" translocation to provide a mechanism for threading and building a signaling-active oligomeric complex.
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Affiliation(s)
- Swapnil C Devarkar
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Brandon Schweibenz
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Chen Wang
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Joseph Marcotrigiano
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA.
| | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
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25
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Lässig C, Lammens K, Gorenflos López JL, Michalski S, Fettscher O, Hopfner KP. Unified mechanisms for self-RNA recognition by RIG-I Singleton-Merten syndrome variants. eLife 2018; 7:e38958. [PMID: 30047865 PMCID: PMC6086658 DOI: 10.7554/elife.38958] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 07/24/2018] [Indexed: 12/13/2022] Open
Abstract
The innate immune sensor retinoic acid-inducible gene I (RIG-I) detects cytosolic viral RNA and requires a conformational change caused by both ATP and RNA binding to induce an active signaling state and to trigger an immune response. Previously, we showed that ATP hydrolysis removes RIG-I from lower-affinity self-RNAs (Lässig et al., 2015), revealing how ATP turnover helps RIG-I distinguish viral from self-RNA and explaining why a mutation in a motif that slows down ATP hydrolysis causes the autoimmune disease Singleton-Merten syndrome (SMS). Here we show that a different, mechanistically unexplained SMS variant, C268F, which is localized in the ATP-binding P-loop, can signal independently of ATP but is still dependent on RNA. The structure of RIG-I C268F in complex with double-stranded RNA reveals that C268F helps induce a structural conformation in RIG-I that is similar to that induced by ATP. Our results uncover an unexpected mechanism to explain how a mutation in a P-loop ATPase can induce a gain-of-function ATP state in the absence of ATP.
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Affiliation(s)
- Charlotte Lässig
- Department of BiochemistryLudwig-Maximilians-Universität MünchenMunichGermany
- Gene Center, Ludwig-Maximilians-Universität MünchenMunichGermany
| | - Katja Lammens
- Department of BiochemistryLudwig-Maximilians-Universität MünchenMunichGermany
- Gene Center, Ludwig-Maximilians-Universität MünchenMunichGermany
| | - Jacob Lucián Gorenflos López
- Department of BiochemistryLudwig-Maximilians-Universität MünchenMunichGermany
- Gene Center, Ludwig-Maximilians-Universität MünchenMunichGermany
| | - Sebastian Michalski
- Department of BiochemistryLudwig-Maximilians-Universität MünchenMunichGermany
- Gene Center, Ludwig-Maximilians-Universität MünchenMunichGermany
| | - Olga Fettscher
- Department of BiochemistryLudwig-Maximilians-Universität MünchenMunichGermany
- Gene Center, Ludwig-Maximilians-Universität MünchenMunichGermany
| | - Karl-Peter Hopfner
- Department of BiochemistryLudwig-Maximilians-Universität MünchenMunichGermany
- Gene Center, Ludwig-Maximilians-Universität MünchenMunichGermany
- Center for Integrated Protein Science MunichMunichGermany
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26
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Yong HY, Luo D. RIG-I-Like Receptors as Novel Targets for Pan-Antivirals and Vaccine Adjuvants Against Emerging and Re-Emerging Viral Infections. Front Immunol 2018; 9:1379. [PMID: 29973930 PMCID: PMC6019452 DOI: 10.3389/fimmu.2018.01379] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/04/2018] [Indexed: 12/18/2022] Open
Abstract
Emerging and re-emerging viruses pose a significant public health challenge around the world, among which RNA viruses are the cause of many major outbreaks of infectious diseases. As one of the early lines of defense in the human immune system, RIG-I-like receptors (RLRs) play an important role as sentinels to thwart the progression of virus infection. The activation of RLRs leads to an antiviral state in the host cells, which triggers the adaptive arm of immunity and ultimately the clearance of viral infections. Hence, RLRs are promising targets for the development of pan-antivirals and vaccine adjuvants. Here, we discuss the opportunities and challenges of developing RLR agonists into antiviral therapeutic agents and vaccine adjuvants against a broad range of viruses.
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Affiliation(s)
- Hui Yee Yong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
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27
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Shah N, Beckham SA, Wilce JA, Wilce M. Combined roles of ATP and small hairpin RNA in the activation of RIG-I revealed by solution-based analysis. Nucleic Acids Res 2018; 46:3169-3186. [PMID: 29346611 PMCID: PMC5887321 DOI: 10.1093/nar/gkx1307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 12/19/2017] [Accepted: 12/24/2017] [Indexed: 12/24/2022] Open
Abstract
RIG-I (retinoic acid inducible gene-I) is a cytosolic innate immune protein that senses viral dsRNA with a 5'-triphosphate overhang. Upon interaction with dsRNA a de-repression of the RIG-I CARD domains takes place that ultimately leads to the production of type I interferons and pro-inflammatory cytokines. Here we investigate the RIG-I conformational rearrangement upon interaction with an activating 5'-triphosphate-10-base pair dsRNA hairpin loop (10bp) compared with a less active 5'-triphosphate-8-base pair dsRNA hairpin loop (8bp). We use size-exclusion chromatography-coupled small-angle X-ray scattering (SAXS) and limited tryptic digest experiments to show that that upon binding to 10 bp, but not 8 bp, RIG-I becomes extended and shows greater flexibility, reflecting the release of its CARDs. We also examined the effect of different ATP analogues on the conformational changes of RIG-I/dsRNA complexes. Of the analogues tested, the addition of ATP transition state analogue ADP-AlFx further assisted in the complete activation of RIG-I in complex with 10bp and also to some extent RIG-I bound to 8bp. Together these data provide solution-based evidence for the molecular mechanism of innate immune signaling by RIG-I as stimulated by short hairpin RNA and ATP.
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Affiliation(s)
- Neelam Shah
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Simone A Beckham
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Jacqueline A Wilce
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Matthew C J Wilce
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
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28
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Wang Y, Du Z, Zheng W, Wu K, Xu D, Luo Q, Zhao Y, Han J, Liu Y, Wang F. Deciphering of interactions between platinated DNA and HMGB1 by hydrogen/deuterium exchange mass spectrometry. Dalton Trans 2018; 46:6187-6195. [PMID: 28426082 DOI: 10.1039/c7dt00275k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A high mobility group box 1 (HMGB1) protein has been reported to recognize both 1,2-intrastrand crosslinked DNA by cisplatin (1,2-cis-Pt-DNA) and monofunctional platinated DNA using trans-[PtCl2(NH3)(thiazole)] (1-trans-PtTz-DNA). However, the molecular basis of recognition between the trans-PtTz-DNA and HMGB1 remains unclear. In the present work, we described a hydrogen/deuterium exchange mass spectrometry (HDX-MS) method in combination with docking simulation to decipher the interactions of platinated DNA with domain A of HMGB1. The global deuterium uptake results indicated that 1-trans-PtTz-DNA bound to HMGB1a slightly tighter than the 1,2-cis-Pt-DNA. The local deuterium uptake at the peptide level revealed that the helices I and II, and loop 1 of HMGB1a were involved in the interactions with both platinated DNA adducts. However, docking simulation disclosed different H-bonding networks and distinct DNA-backbone orientations in the two Pt-DNA-HMGB1a complexes. Moreover, the Phe37 residue of HMGB1a was shown to play a key role in the recognition between HMGB1a and the platinated DNAs. In the cis-Pt-DNA-HMGB1a complex, the phenyl ring of Phe37 intercalates into a hydrophobic notch created by the two platinated guanines, while in the trans-PtTz-DNA-HMGB1a complex the phenyl ring appears to intercalate into a hydrophobic crevice formed by the platinated guanine and the opposite adenine in the complementary strand, forming a penta-layer π-π stacking associated with the adjacent thymine and the thiazole ligand. This work demonstrates that HDX-MS associated with docking simulation is a powerful tool to elucidate the interactions between platinated DNAs and proteins.
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Affiliation(s)
- Yuanyuan Wang
- Beijing National Laboratory for Molecular Sciences, National Centre for Mass Spectrometry in Beijing, CAS Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
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29
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Long Y, Bolanos B, Gong L, Liu W, Goodrich KJ, Yang X, Chen S, Gooding AR, Maegley KA, Gajiwala KS, Brooun A, Cech TR, Liu X. Conserved RNA-binding specificity of polycomb repressive complex 2 is achieved by dispersed amino acid patches in EZH2. eLife 2017; 6. [PMID: 29185984 PMCID: PMC5706960 DOI: 10.7554/elife.31558] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 11/09/2017] [Indexed: 12/19/2022] Open
Abstract
Polycomb repressive complex 2 (PRC2) is a key chromatin modifier responsible for methylation of lysine 27 in histone H3. PRC2 has been shown to interact with thousands of RNA species in vivo, but understanding the physiological function of RNA binding has been hampered by the lack of separation-of-function mutants. Here, we use comprehensive mutagenesis and hydrogen deuterium exchange mass spectrometry (HDX-MS) to identify critical residues for RNA interaction in PRC2 core complexes from Homo sapiens and Chaetomium thermophilum, for which crystal structures are known. Preferential binding of G-quadruplex RNA is conserved, surprisingly using different protein elements. Key RNA-binding residues are spread out along the surface of EZH2, with other subunits including EED also contributing, and missense mutations of some of these residues have been found in cancer patients. The unusual nature of this protein-RNA interaction provides a paradigm for other epigenetic modifiers that bind RNA without canonical RNA-binding motifs.
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Affiliation(s)
- Yicheng Long
- Department of Chemistry and Biochemistry, BioFrontiers Institute, Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, United States
| | - Ben Bolanos
- Worldwide Medicinal Chemistry, Worldwide Research and Development, Pfizer Inc., San Diego, United States
| | - Lihu Gong
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, UT Southwestern Medical Center, Dallas, United States.,Department of Biophysics, UT Southwestern Medical Center, Dallas, United States
| | - Wei Liu
- Worldwide Medicinal Chemistry, Worldwide Research and Development, Pfizer Inc., San Diego, United States
| | - Karen J Goodrich
- Department of Chemistry and Biochemistry, BioFrontiers Institute, Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, United States
| | - Xin Yang
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, UT Southwestern Medical Center, Dallas, United States.,Department of Biophysics, UT Southwestern Medical Center, Dallas, United States
| | - Siming Chen
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, UT Southwestern Medical Center, Dallas, United States.,Department of Biophysics, UT Southwestern Medical Center, Dallas, United States
| | - Anne R Gooding
- Department of Chemistry and Biochemistry, BioFrontiers Institute, Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, United States
| | - Karen A Maegley
- Oncology Research Unit, Worldwide Research and Development, Pfizer Inc., San Diego, United States
| | - Ketan S Gajiwala
- Worldwide Medicinal Chemistry, Worldwide Research and Development, Pfizer Inc., San Diego, United States
| | - Alexei Brooun
- Worldwide Medicinal Chemistry, Worldwide Research and Development, Pfizer Inc., San Diego, United States
| | - Thomas R Cech
- Department of Chemistry and Biochemistry, BioFrontiers Institute, Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, United States
| | - Xin Liu
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, Division of Basic Research, Department of Obstetrics and Gynecology, UT Southwestern Medical Center, Dallas, United States.,Department of Biophysics, UT Southwestern Medical Center, Dallas, United States
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30
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HDX reveals the conformational dynamics of DNA sequence specific VDR co-activator interactions. Nat Commun 2017; 8:923. [PMID: 29030554 PMCID: PMC5640644 DOI: 10.1038/s41467-017-00978-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/09/2017] [Indexed: 01/20/2023] Open
Abstract
The vitamin D receptor/retinoid X receptor-α heterodimer (VDRRXRα) regulates bone mineralization via transcriptional control of osteocalcin (BGLAP) gene and is the receptor for 1α,25-dihydroxyvitamin D3 (1,25D3). However, supra-physiological levels of 1,25D3 activates the calcium-regulating gene TRPV6 leading to hypercalcemia. An approach to attenuate this adverse effect is to develop selective VDR modulators (VDRMs) that differentially activate BGLAP but not TRPV6. Here we present structural insight for the action of a VDRM compared with agonists by employing hydrogen/deuterium exchange. Agonist binding directs crosstalk between co-receptors upon DNA binding, stabilizing the activation function 2 (AF2) surfaces of both receptors driving steroid receptor co-activator-1 (SRC1) interaction. In contrast, AF2 of VDR within VDRM:BGLAP bound heterodimer is more vulnerable for large stabilization upon SRC1 interaction compared with VDRM:TRPV6 bound heterodimer. These results reveal that the combination of ligand structure and DNA sequence tailor the transcriptional activity of VDR toward specific target genes. The vitamin D receptor/retinoid X receptor-α heterodimer (VDRRXRα) regulates bone mineralization. Here the authors employ hydrogen/deuterium exchange (HDX) mass spectrometry to study the conformational dynamics of VDRRXRα and give mechanistic insights into how VDRRXRα controls the transcriptional activity of specific genes.
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31
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Conformational dynamics of 1-deoxy-d-xylulose 5-phosphate synthase on ligand binding revealed by H/D exchange MS. Proc Natl Acad Sci U S A 2017; 114:9355-9360. [PMID: 28808005 DOI: 10.1073/pnas.1619981114] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The enzyme 1-deoxy-d-xylulose 5-phosphate synthase (DXPS) is a key enzyme in the methylerythritol 4-phosphate pathway and is a target for the development of antibiotics, herbicides, and antimalarial drugs. DXPS catalyzes the formation of 1-deoxy-d-xylulose 5-phosphate (DXP), a branch point metabolite in isoprenoid biosynthesis, and is also used in the biosynthesis of thiamin (vitamin B1) and pyridoxal (vitamin B6). Previously, we found that DXPS is unique among the superfamily of thiamin diphosphate (ThDP)-dependent enzymes in stabilizing the predecarboxylation intermediate, C2-alpha-lactyl-thiamin diphosphate (LThDP), which has subsequent decarboxylation that is triggered by d-glyceraldehyde 3-phosphate (GAP). Herein, we applied hydrogen-deuterium (H/D) exchange MS (HDX-MS) of full-length Escherichia coli DXPS to provide a snapshot of the conformational dynamics of this enzyme, leading to the following conclusions. (i) The high sequence coverage of DXPS allowed us to monitor structural changes throughout the entire enzyme, including two segments (spanning residues 183-238 and 292-317) not observed by X-ray crystallography. (ii) Three regions of DXPS (spanning residues 42-58, 183-199, and 278-298) near the active center displayed both EX1 (monomolecular) and EX2 (bimolecuar) H/D exchange (HDX) kinetic behavior in both ligand-free and ligand-bound states. All other peptides behaved according to the common EX2 kinetic mechanism. (iii) The observation of conformational changes on DXPS provides support for the role of conformational dynamics in the DXPS mechanism: The closed conformation of DXPS is critical for stabilization of LThDP, whereas addition of GAP converts DXPS to the open conformation that coincides with decarboxylation of LThDP and DXP release.
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32
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Ma Z, Yu Y, Xiao Y, Opriessnig T, Wang R, Yang L, Nan Y, Samal SK, Halbur PG, Zhang YJ. The middle half genome of interferon-inducing porcine reproductive and respiratory syndrome virus strain A2MC2 is essential for interferon induction. J Gen Virol 2017; 98:1720-1729. [PMID: 28699875 DOI: 10.1099/jgv.0.000819] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is known to antagonize the innate immune response. An atypical PRRSV strain A2MC2 is capable of inducing synthesis of type I interferons (IFNs) in cultured cells. Here, we show that the middle half of the A2MC2 genome is needed for triggering the IFN synthesis. First, a cDNA infectious clone of this atypical strain was constructed as a DNA-launched version. Virus recovery was achieved from the infectious clone and the recovered virus, rA2MC2, was characterized. The rA2MC2 retained the feature of IFN induction in cultured cells. Infection of pigs with the rA2MC2 virus caused viremia similar to that of the wild-type virus. Chimeric infectious clones were constructed by swapping genomic fragments with a cDNA clone of a moderately virulent strain VR-2385 that antagonizes IFN induction. Analysis of the rescued chimeric viruses demonstrated that the middle two fragments, ranging from nt4545 to nt12709 of the A2MC2 genome, were needed for the IFN induction, whereas the chimeric viruses containing any one of the two A2MC2 fragments failed to do so. The results and the cDNA infectious clone of the IFN-inducing A2MC2 will facilitate further study of its biology, ultimately leading towards the development of an improved vaccine against PRRS.
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Affiliation(s)
- Zexu Ma
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Ying Yu
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Yueqiang Xiao
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Tanja Opriessnig
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.,The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, Scotland, UK
| | - Rong Wang
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Liping Yang
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Yuchen Nan
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Siba K Samal
- Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Patrick G Halbur
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Yan-Jin Zhang
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
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33
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Chikungunya virus nsP4 RNA-dependent RNA polymerase core domain displays detergent-sensitive primer extension and terminal adenylyltransferase activities. Antiviral Res 2017; 143:38-47. [DOI: 10.1016/j.antiviral.2017.04.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 04/04/2017] [Indexed: 01/10/2023]
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34
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Analysis of phosphoinositide 3-kinase inhibitors by bottom-up electron-transfer dissociation hydrogen/deuterium exchange mass spectrometry. Biochem J 2017; 474:1867-1877. [PMID: 28381646 PMCID: PMC5544108 DOI: 10.1042/bcj20170127] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/03/2017] [Accepted: 04/05/2017] [Indexed: 12/22/2022]
Abstract
Until recently, one of the major limitations of hydrogen/deuterium exchange mass spectrometry (HDX-MS) was the peptide-level resolution afforded by proteolytic digestion. This limitation can be selectively overcome through the use of electron-transfer dissociation to fragment peptides in a manner that allows the retention of the deuterium signal to produce hydrogen/deuterium exchange tandem mass spectrometry (HDX-MS/MS). Here, we describe the application of HDX-MS/MS to structurally screen inhibitors of the oncogene phosphoinositide 3-kinase catalytic p110α subunit. HDX-MS/MS analysis is able to discern a conserved mechanism of inhibition common to a range of inhibitors. Owing to the relatively minor amounts of protein required, this technique may be utilised in pharmaceutical development for screening potential therapeutics.
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Domsgen E, Lind K, Kong L, Hühn MH, Rasool O, van Kuppeveld F, Korsgren O, Lahesmaa R, Flodström-Tullberg M. An IFIH1 gene polymorphism associated with risk for autoimmunity regulates canonical antiviral defence pathways in Coxsackievirus infected human pancreatic islets. Sci Rep 2016; 6:39378. [PMID: 28000722 PMCID: PMC5175199 DOI: 10.1038/srep39378] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/23/2016] [Indexed: 02/08/2023] Open
Abstract
The IFIH1 gene encodes the pattern recognition receptor MDA5. A common polymorphism in IFIH1 (rs1990760, A946T) confers increased risk for autoimmune disease, including type 1-diabetes (T1D). Coxsackievirus infections are linked to T1D and cause beta-cell damage in vitro. Here we demonstrate that the rs1990760 polymorphism regulates the interferon (IFN) signature expressed by human pancreatic islets following Coxsackievirus infection. A strong IFN signature was associated with high expression of IFNλ1 and IFNλ2, linking rs1990760 to the expression of type III IFNs. In the high-responding genotype, IRF-1 expression correlated with that of type III IFN, suggesting a positive-feedback on type III IFN transcription. In summary, our study uncovers an influence of rs1990760 on the canonical effector function of MDA5 in response to an acute infection of primary human parenchymal cells with a clinically relevant virus linked to human T1D. It also highlights a previously unrecognized connection between the rs1990760 polymorphism and the expression level of type III IFNs.
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Affiliation(s)
- Erna Domsgen
- The Center for Infectious Medicine, Department of Medicine HS, Karolinska Institutet, Karolinska University Hospital, Stockholm, 141 86, Sweden
| | - Katharina Lind
- The Center for Infectious Medicine, Department of Medicine HS, Karolinska Institutet, Karolinska University Hospital, Stockholm, 141 86, Sweden
| | - Lingjia Kong
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, 205 20, Finland
| | - Michael H Hühn
- The Center for Infectious Medicine, Department of Medicine HS, Karolinska Institutet, Karolinska University Hospital, Stockholm, 141 86, Sweden
| | - Omid Rasool
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, 205 20, Finland
| | - Frank van Kuppeveld
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, 3584, The Netherlands
| | - Olle Korsgren
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, 751 05, Sweden
| | - Riitta Lahesmaa
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, 205 20, Finland
| | - Malin Flodström-Tullberg
- The Center for Infectious Medicine, Department of Medicine HS, Karolinska Institutet, Karolinska University Hospital, Stockholm, 141 86, Sweden.,Institute of Biosciences and Medical Technologies, University of Tampere, Tampere, 33520, Finland
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36
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The excluded DNA strand is SEW important for hexameric helicase unwinding. Methods 2016; 108:79-91. [DOI: 10.1016/j.ymeth.2016.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/07/2016] [Accepted: 04/07/2016] [Indexed: 02/04/2023] Open
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Du X, Pan T, Xu J, Zhang Y, Song W, Yi Z, Yuan Z. Hepatitis C virus replicative double-stranded RNA is a potent interferon inducer that triggers interferon production through MDA5. J Gen Virol 2016; 97:2868-2882. [PMID: 27655134 DOI: 10.1099/jgv.0.000607] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The cytoplasmic RNA sensors, retinoic acid-inducible gene I and melanoma differentiation-associated gene 5, play crucial roles in innate sensing of hepatitis C virus (HCV). However, the exact identity of the IFN inducer generated during HCV infection is poorly understood. To identify the IFN inducer, we extracted the RNAs from HCV-replicating cells and introduced these into IFN signalling-competent cells to examine IFN production. RNAs isolated from HCV-replicating cells triggered robust IFN-β and IFN-λ production in Huh7 cells in a viral replication-dependent manner, preferentially through the melanoma differentiation-associated gene 5 but not through the retinoic acid-inducible gene I-mediated pathway. The IFN-inducing capacity of HCV RNA survived after calf intestinal alkaline phosphatase and ssRNA-specific S1 nuclease treatment, but was completely eliminated by dsRNA-specific RNase III digestion, suggesting that viral replicative dsRNA is an IFN inducer. Furthermore, HCV viral RNA extracted from replicating cells was sensitive to 5'-monophosphate-dependent 5'→3' exonuclease (TER) digestion, suggesting that the HCV genome lacks a 5'-triphosphate or -diphosphate. In semi-permeabilized cells, the HCV IFN inducer primarily resided in an enclosed membranous structure that protects the IFN inducer from RNase digestion. Taken together, we identified HCV replicative dsRNA as a viral IFN inducer enclosed within the viral replication factory.
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Affiliation(s)
- Xiaoting Du
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Tingting Pan
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Jun Xu
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Yang Zhang
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Wuhui Song
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Zhigang Yi
- Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Zhenghong Yuan
- Institute of Biomedical Sciences, Fudan University, Shanghai, PR China.,Key Laboratory of Medical Molecular Virology, Department of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, PR China.,Institute of Medical Microbiology, Fudan University, Shanghai, PR China
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Leung DW, Amarasinghe GK. When your cap matters: structural insights into self vs non-self recognition of 5' RNA by immunomodulatory host proteins. Curr Opin Struct Biol 2016; 36:133-41. [PMID: 26916433 PMCID: PMC5218996 DOI: 10.1016/j.sbi.2016.02.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 02/04/2016] [Indexed: 12/13/2022]
Abstract
Cytosolic recognition of viral RNA is important for host innate immune responses. Differential recognition of self vs non-self RNA is a considerable challenge as the inability to differentiate may trigger aberrant immune responses. Recent work identified the composition of the RNA 5', including the 5' cap and its methylation state, as an important determinant of recognition by the host. Recent studies have advanced our understanding of the modified 5' RNA recognition and viral antagonism of RNA receptors. Here, we will discuss RIG-I and IFIT proteins as examples of host proteins that detect dsRNA and ssRNA, respectively.
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Affiliation(s)
- Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine, Campus Box 8118, 660 South Euclid Avenue, St Louis, MO 63110, United States.
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, Campus Box 8118, 660 South Euclid Avenue, St Louis, MO 63110, United States.
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Looney BM, Xia CQ, Concannon P, Ostrov DA, Clare-Salzler MJ. Effects of type 1 diabetes-associated IFIH1 polymorphisms on MDA5 function and expression. Curr Diab Rep 2015; 15:96. [PMID: 26385483 DOI: 10.1007/s11892-015-0656-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent evidence has highlighted the role of the innate immune system in type 1 diabetes (T1D) pathogenesis. Specifically, aberrant activation of the interferon response prior to seroconversion of T1D-associated autoantibodies supports a role for the interferon response as a precipitating event toward activation of autoimmunity. Melanoma differentiation-associated protein 5 (MDA5), encoded by IFIH1, mediates the innate immune system's interferon response to certain viral species that form double-stranded RNA (dsRNA), the MDA5 ligand, during their life cycle. Extensive research has associated single nucleotide polymorphisms (SNPs) within the coding region of IFIH1 with T1D. This review discusses the different risk and protective IFIH1 alleles in the context of recent structural and functional analysis that relate to MDA5 regulation of interferon responses. These studies have provided a functional hypothesis for IFIH1 T1D-associated SNPs' effects on MDA5-mediated interferon responses as well as supporting the genome-wide association (GWA) studies that first associated IFIH1 with T1D.
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Affiliation(s)
- Benjamin M Looney
- Department of Pathology, Immunology and Laboratory Medicine, College of Medicine Interdisciplinary Program in Biomedical Sciences, University of Florida, 1600 SW Archer Rd., Gainesville, FL, 32610, USA.
| | - Chang-Qing Xia
- Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, 1600 SW Archer Rd., Gainesville, FL, 32610, USA.
| | - Patrick Concannon
- University of Florida Genetics Institute, 2033 Mowry Rd., P.O. Box 103610, Gainesville, FL, 32611, USA.
| | - David A Ostrov
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, 2033 Mowry Rd., P.O. Box 103633, Gainesville, FL, 32611, USA.
| | - Michael J Clare-Salzler
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, 2033 Mowry Rd., P.O. Box 103633, Gainesville, FL, 32611, USA.
- Center for Immunology and Transplantation, University of Florida, 1600 SW Archer Rd., P.O. Box 100275, Gainesville, FL, 32610, USA.
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Rawling DC, Fitzgerald ME, Pyle AM. Establishing the role of ATP for the function of the RIG-I innate immune sensor. eLife 2015; 4:e09391. [PMID: 26371557 PMCID: PMC4622095 DOI: 10.7554/elife.09391] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/14/2015] [Indexed: 12/24/2022] Open
Abstract
Retinoic acid-inducible gene I (RIG-I) initiates a rapid innate immune response upon detection and binding to viral ribonucleic acid (RNA). This signal activation occurs only when pathogenic RNA is identified, despite the ability of RIG-I to bind endogenous RNA while surveying the cytoplasm. Here we show that ATP binding and hydrolysis by RIG-I play a key role in the identification of viral targets and the activation of signaling. Using biochemical and cell-based assays together with mutagenesis, we show that ATP binding, and not hydrolysis, is required for RIG-I signaling on viral RNA. However, we show that ATP hydrolysis does provide an important function by recycling RIG-I and promoting its dissociation from non-pathogenic RNA. This activity provides a valuable proof-reading mechanism that enhances specificity and prevents an antiviral response upon encounter with host RNA molecules.
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Affiliation(s)
- David C Rawling
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States
| | - Megan E Fitzgerald
- Department of Molecular, Cellular and Developmental Biology, Howard Hughes Medical Institute, Yale University, New Haven, United States
| | - Anna Marie Pyle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States
- Department of Chemistry, Howard Hughes Medical Institute, Yale University, New Haven, United States
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41
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Sparrer KMJ, Gack MU. Intracellular detection of viral nucleic acids. Curr Opin Microbiol 2015; 26:1-9. [PMID: 25795286 PMCID: PMC5084527 DOI: 10.1016/j.mib.2015.03.001] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/02/2015] [Indexed: 12/22/2022]
Abstract
Successful clearance of a microbial infection depends on the concerted action of both the innate and adaptive arms of the immune system. Accurate recognition of an invading pathogen is the first and most crucial step in eliciting effective antimicrobial defense mechanisms. In recent years, remarkable progress has been made towards understanding the molecular details of how the innate immune system recognizes microbial signatures, commonly called pathogen-associated molecular patterns (PAMPs). For viral pathogens, nucleic acids-both viral genomes and viral replication products-represent a major class of PAMPs that trigger antiviral host responses via activation of germline-encoded innate immune receptors. Here we summarize recent advances in intracellular innate sensing mechanisms of viral RNA and DNA.
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Affiliation(s)
- Konstantin M J Sparrer
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Michaela U Gack
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.
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42
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Louber J, Brunel J, Uchikawa E, Cusack S, Gerlier D. Kinetic discrimination of self/non-self RNA by the ATPase activity of RIG-I and MDA5. BMC Biol 2015; 13:54. [PMID: 26215161 PMCID: PMC4517655 DOI: 10.1186/s12915-015-0166-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 07/11/2015] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The cytoplasmic RIG-like receptors are responsible for the early detection of viruses and other intracellular microbes by activating the innate immune response mediated by type I interferons (IFNs). RIG-I and MDA5 detect virus-specific RNA motifs with short 5'-tri/diphosphorylated, blunt-end double-stranded RNA (dsRNA) and >0.5-2 kb long dsRNA as canonical agonists, respectively. However, in vitro, they can bind to many RNA species, while in cells there is an activation threshold. As SF2 helicase/ATPase family members, ATP hydrolysis is dependent on co-operative RNA and ATP binding. Whereas simultaneous ATP and cognate RNA binding is sufficient to activate RIG-I by releasing autoinhibition of the signaling domains, the physiological role of the ATPase activity of RIG-I and MDA5 remains controversial. RESULTS A cross-analysis of a rationally designed panel of RNA binding and ATPase mutants and truncated receptors, using type I IFN promoter activation as readout, allows us to refine our understanding of the structure-function relationships of RIG-I and MDA5. RNA activation of RIG-I depends on multiple critical RNA binding sites in its helicase domain as confirmed by functional evidence using novel mutations. We found that RIG-I or MDA5 mutants with low ATP hydrolysis activity exhibit constitutive activity but this was fully reverted when associated with mutations preventing RNA binding to the helicase domain. We propose that the turnover kinetics of the ATPase domain enables the discrimination of self/non-self RNA by both RIG-I and MDA5. Non-cognate, possibly self, RNA binding would lead to fast ATP turnover and RNA disassociation and thus insufficient time for the caspase activation and recruitment domains (CARDs) to promote downstream signaling, whereas tighter cognate RNA binding provides a longer time window for downstream events to be engaged. CONCLUSIONS The exquisite fine-tuning of RIG-I and MDA5 RNA-dependent ATPase activity coupled to CARD release allows a robust IFN response from a minor subset of non-self RNAs within a sea of cellular self RNAs. This avoids the eventuality of deleterious autoimmunity effects as have been recently described to arise from natural gain-of-function alleles of RIG-I and MDA5.
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Affiliation(s)
- Jade Louber
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France.
- INSERM, U1111, Lyon, France.
- Ecole Normale Supérieure de Lyon, Lyon, France.
- Université Claude Bernard Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France.
- CNRS, UMR5308, Lyon, France.
| | - Joanna Brunel
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France.
- INSERM, U1111, Lyon, France.
- Ecole Normale Supérieure de Lyon, Lyon, France.
- Université Claude Bernard Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France.
- CNRS, UMR5308, Lyon, France.
| | - Emiko Uchikawa
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, BP 181, 38042, Grenoble, Cedex 9, France.
- Unit of Virus Host Cell Interactions, UJF-EMBL-CNRS, UMI 3265, 71 Avenue des Martyrs, BP 181, 38042, Grenoble, Cedex 9, France.
| | - Stephen Cusack
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, BP 181, 38042, Grenoble, Cedex 9, France.
- Unit of Virus Host Cell Interactions, UJF-EMBL-CNRS, UMI 3265, 71 Avenue des Martyrs, BP 181, 38042, Grenoble, Cedex 9, France.
| | - Denis Gerlier
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon, France.
- INSERM, U1111, Lyon, France.
- Ecole Normale Supérieure de Lyon, Lyon, France.
- Université Claude Bernard Lyon 1, Centre International de Recherche en Infectiologie, Lyon, France.
- CNRS, UMR5308, Lyon, France.
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Martínez T, Jiménez AI, Pañeda C. Short-interference RNAs: becoming medicines. EXCLI JOURNAL 2015; 14:714-46. [PMID: 26648823 PMCID: PMC4669907 DOI: 10.17179/excli2015-297] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 05/12/2015] [Indexed: 12/30/2022]
Abstract
RNA interference is a cellular mechanism by which small molecules of double stranded RNA modulate gene expression acting on the concentration and/or availability of a given messenger RNA. Almost 10 years after Fire and Mello received the Nobel Prize for the discovery of this mechanism in flat worms, RNA interference is on the edge of becoming a new class of therapeutics. With various phase III studies underway, the following years will determine whether RNAi-therapeutics can rise up to the challenge and become mainstream medicines. The present review gives a thorough overview of the current status of this technology focusing on the path to the clinic of this new class of compounds.
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Affiliation(s)
- Tamara Martínez
- Sylentis, R&D department c/Santiago Grisolía, Tres Cantos, Madrid, Spain
| | - Ana Isabel Jiménez
- Sylentis, R&D department c/Santiago Grisolía, Tres Cantos, Madrid, Spain
| | - Covadonga Pañeda
- Sylentis, R&D department c/Santiago Grisolía, Tres Cantos, Madrid, Spain
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44
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Zhao Y, Soh TS, Zheng J, Chan KWK, Phoo WW, Lee CC, Tay MYF, Swaminathan K, Cornvik TC, Lim SP, Shi PY, Lescar J, Vasudevan SG, Luo D. A crystal structure of the Dengue virus NS5 protein reveals a novel inter-domain interface essential for protein flexibility and virus replication. PLoS Pathog 2015; 11:e1004682. [PMID: 25775415 PMCID: PMC4361662 DOI: 10.1371/journal.ppat.1004682] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 01/12/2015] [Indexed: 01/28/2023] Open
Abstract
Flavivirus RNA replication occurs within a replication complex (RC) that assembles on ER membranes and comprises both non-structural (NS) viral proteins and host cofactors. As the largest protein component within the flavivirus RC, NS5 plays key enzymatic roles through its N-terminal methyltransferase (MTase) and C-terminal RNA-dependent-RNA polymerase (RdRp) domains, and constitutes a major target for antivirals. We determined a crystal structure of the full-length NS5 protein from Dengue virus serotype 3 (DENV3) at a resolution of 2.3 Å in the presence of bound SAH and GTP. Although the overall molecular shape of NS5 from DENV3 resembles that of NS5 from Japanese Encephalitis Virus (JEV), the relative orientation between the MTase and RdRp domains differs between the two structures, providing direct evidence for the existence of a set of discrete stable molecular conformations that may be required for its function. While the inter-domain region is mostly disordered in NS5 from JEV, the NS5 structure from DENV3 reveals a well-ordered linker region comprising a short 310 helix that may act as a swivel. Solution Hydrogen/Deuterium Exchange Mass Spectrometry (HDX-MS) analysis reveals an increased mobility of the thumb subdomain of RdRp in the context of the full length NS5 protein which correlates well with the analysis of the crystallographic temperature factors. Site-directed mutagenesis targeting the mostly polar interface between the MTase and RdRp domains identified several evolutionarily conserved residues that are important for viral replication, suggesting that inter-domain cross-talk in NS5 regulates virus replication. Collectively, a picture for the molecular origin of NS5 flexibility is emerging with profound implications for flavivirus replication and for the development of therapeutics targeting NS5. DENV causes widespread mosquito-borne viral infections worldwide and nearly 40% of the world’s population is at risk of being infected. Currently, no licensed vaccines or specific drugs are available to treat severe infections by DENV. NS5 is a large protein of 900 amino acids composed of two domains with several key enzymatic activities for viral RNA replication in the host cell and constitutes a prime target for the design of antiviral inhibitors. We succeeded in trapping a stable conformation of the full-length NS5 protein and report its crystal structure at a resolution of 2.3 Å. This conformation reveals the entire inter-domain region and clarifies the determinants of NS5 flexibility. The inter-domain interface is stabilized by several polar contacts between residues projecting from the MTase and RdRp domains of NS5. Several evolutionarily conserved residues at the interface play a crucial role for virus replication as shown by reverse genetics, although the analogous mutations mostly do not abolish the in vitro enzymatic activities of the recombinant proteins.
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Affiliation(s)
- Yongqian Zhao
- Program in Emerging Infectious Diseases, DUKE-NUS Graduate Medical School, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
| | - Tingjin Sherryl Soh
- School of Biological Sciences, Nanyang Technological University, Singapore
- Novartis Institute for Tropical Diseases, Singapore
| | - Jie Zheng
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Kitti Wing Ki Chan
- Program in Emerging Infectious Diseases, DUKE-NUS Graduate Medical School, Singapore
| | - Wint Wint Phoo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Chin Chin Lee
- Program in Emerging Infectious Diseases, DUKE-NUS Graduate Medical School, Singapore
| | - Moon Y. F. Tay
- Program in Emerging Infectious Diseases, DUKE-NUS Graduate Medical School, Singapore
| | - Kunchithapadam Swaminathan
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Tobias C. Cornvik
- School of Biological Sciences, Nanyang Technological University, Singapore
| | | | - Pei-Yong Shi
- Novartis Institute for Tropical Diseases, Singapore
| | - Julien Lescar
- School of Biological Sciences, Nanyang Technological University, Singapore
- UPMC UMRS CR7—CNRS ERL 8255-INSERM U1135 Centre d’Immunologie et des Maladies Infectieuses, Centre Hospitalier Universitaire Pitié-Salpêtrière, Faculté de Médecine Pierre et Marie Curie, Paris, France
- * E-mail: (JL); (SGV); (DL)
| | - Subhash G. Vasudevan
- Program in Emerging Infectious Diseases, DUKE-NUS Graduate Medical School, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
- * E-mail: (JL); (SGV); (DL)
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
- * E-mail: (JL); (SGV); (DL)
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