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Liu Y, Hou D, Chen W, Lu X, Komaniecki GP, Xu Y, Yu T, Zhang SM, Linder ME, Lin H. MAVS Cys508 palmitoylation promotes its aggregation on the mitochondrial outer membrane and antiviral innate immunity. Proc Natl Acad Sci U S A 2024; 121:e2403392121. [PMID: 39141356 PMCID: PMC11348129 DOI: 10.1073/pnas.2403392121] [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: 02/17/2024] [Accepted: 07/08/2024] [Indexed: 08/15/2024] Open
Abstract
Cysteine palmitoylation or S-palmitoylation catalyzed by the ZDHHC family of acyltransferases regulates the biological function of numerous mammalian proteins as well as viral proteins. However, understanding of the role of S-palmitoylation in antiviral immunity against RNA viruses remains very limited. The adaptor protein MAVS forms functionally essential prion-like aggregates upon activation by viral RNA-sensing RIG-I-like receptors. Here, we identify that MAVS, a C-terminal tail-anchored mitochondrial outer membrane protein, is S-palmitoylated by ZDHHC7 at Cys508, a residue adjacent to the tail-anchor transmembrane helix. Using superresolution microscopy and other biochemical techniques, we found that the mitochondrial localization of MAVS at resting state mainly depends on its transmembrane tail-anchor, without regulation by Cys508 S-palmitoylation. However, upon viral infection, MAVS S-palmitoylation stabilizes its aggregation on the mitochondrial outer membrane and thus promotes subsequent propagation of antiviral signaling. We further show that inhibition of MAVS S-palmitoylation increases the host susceptibility to RNA virus infection, highlighting the importance of S-palmitoylation in the antiviral innate immunity. Also, our results indicate ZDHHC7 as a potential therapeutic target for MAVS-related autoimmune diseases.
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Affiliation(s)
- Yinong Liu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - Dan Hou
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - Wenzhe Chen
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - Xuan Lu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | | | - Yilai Xu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - Tao Yu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - Sophia M. Zhang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
| | - Maurine E. Linder
- Department of Molecular Medicine, Cornell University, Ithaca, NY14853
| | - Hening Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14853
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
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2
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Desai M, Hemant, Deo A, Naik J, Dhamale P, Kshirsagar A, Bose T, Majumdar A. Mrj is a chaperone of the Hsp40 family that regulates Orb2 oligomerization and long-term memory in Drosophila. PLoS Biol 2024; 22:e3002585. [PMID: 38648719 PMCID: PMC11034981 DOI: 10.1371/journal.pbio.3002585] [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: 03/27/2023] [Accepted: 03/12/2024] [Indexed: 04/25/2024] Open
Abstract
Orb2 the Drosophila homolog of cytoplasmic polyadenylation element binding (CPEB) protein forms prion-like oligomers. These oligomers consist of Orb2A and Orb2B isoforms and their formation is dependent on the oligomerization of the Orb2A isoform. Drosophila with a mutation diminishing Orb2A's prion-like oligomerization forms long-term memory but fails to maintain it over time. Since this prion-like oligomerization of Orb2A plays a crucial role in the maintenance of memory, here, we aim to find what regulates this oligomerization. In an immunoprecipitation-based screen, we identify interactors of Orb2A in the Hsp40 and Hsp70 families of proteins. Among these, we find an Hsp40 family protein Mrj as a regulator of the conversion of Orb2A to its prion-like form. Mrj interacts with Hsp70 proteins and acts as a chaperone by interfering with the aggregation of pathogenic Huntingtin. Unlike its mammalian homolog, we find Drosophila Mrj is neither an essential gene nor causes any gross neurodevelopmental defect. We observe a loss of Mrj results in a reduction in Orb2 oligomers. Further, Mrj knockout exhibits a deficit in long-term memory and our observations suggest Mrj is needed in mushroom body neurons for the regulation of long-term memory. Our work implicates a chaperone Mrj in mechanisms of memory regulation through controlling the oligomerization of Orb2A and its association with the translating ribosomes.
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Affiliation(s)
- Meghal Desai
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Hemant
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Ankita Deo
- Institute of Bioinformatics and Biotechnology (IBB), Savitribai Phule Pune University, Pune, India
| | - Jagyanseni Naik
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Prathamesh Dhamale
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Avinash Kshirsagar
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Tania Bose
- Institute of Bioinformatics and Biotechnology (IBB), Savitribai Phule Pune University, Pune, India
| | - Amitabha Majumdar
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
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3
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Liu Q, Chen S, Tian R, Xue B, Li H, Guo M, Liu S, Yan M, You R, Wang L, Yang D, Wan M, Zhu H. 3β-hydroxysteroid-Δ24 reductase dampens anti-viral innate immune responses by targeting K27 ubiquitination of MAVS and STING. J Virol 2023; 97:e0151323. [PMID: 38032198 PMCID: PMC10734464 DOI: 10.1128/jvi.01513-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/02/2023] [Indexed: 12/01/2023] Open
Abstract
IMPORTANCE The precise regulation of the innate immune response is essential for the maintenance of homeostasis. MAVS and STING play key roles in immune signaling pathways activated by RNA and DNA viruses, respectively. Here, we showed that DHCR24 impaired the antiviral response by targeting MAVS and STING. Notably, DHCR24 interacts with MAVS and STING and inhibits TRIM21-triggered K27-linked ubiquitination of MAVS and AMFR-triggered K27-linked ubiquitination of STING, restraining the activation of MAVS and STING, respectively. Together, this study elucidates how one cholesterol key enzyme orchestrates two antiviral signal transduction pathways.
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Affiliation(s)
- Qian Liu
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Shengwen Chen
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Renyun Tian
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Binbin Xue
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Huiyi Li
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Mengmeng Guo
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Shun Liu
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Ming Yan
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Ruina You
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Luoling Wang
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Di Yang
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Mengyu Wan
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
| | - Haizhen Zhu
- Institute of Pathogen Biology and Immunology, College of Biology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China
- />Department of Pathogen Biology and Immunology, Key Laboratory of Tropical Translational Medicine of Ministry of Education, Institute of Pathogen Biology and Immunology, School of Basic Medicine and Life Science, The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Hainan, China
- Department of Clinical Laboratory of the Second Affiliated Hospital of Hainan Medical University, Hainan Medical University, Hainan, China
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4
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Zhang H, Li X, Wang Y, Liu X, Guo J, Wang Z, Zhang L, Xiong S, Dong C. Genome-Wide CRISPR/Cas9 Screening Identifies That Mitochondrial Solute Carrier SLC25A23 Attenuates Type I IFN Antiviral Immunity via Interfering with MAVS Aggregation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:1406-1417. [PMID: 37695673 DOI: 10.4049/jimmunol.2300187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 08/24/2023] [Indexed: 09/12/2023]
Abstract
Activation of the mitochondrial antiviral signaling (MAVS) adaptor, also known as IPS-1, VISA, or Cardif, is crucial for antiviral immunity in retinoic acid-inducible gene I (RIG-I)-like receptor signaling. Upon interacting with RIG-I, MAVS undergoes K63-linked polyubiquitination by the E3 ligase Trim31, and subsequently aggregates to activate downstream signaling effectors. However, the molecular mechanisms that modulate MAVS activation are not yet fully understood. In this study, the mitochondrial solute carrier SLC25A23 was found to attenuate type I IFN antiviral immunity using genome-wide CRISPR/Cas9 screening. SLC25A23 interacts with Trim31, interfering with its binding of Trim31 to MAVS. Indeed, SLC25A23 downregulation was found to increase K63-linked polyubiquitination and subsequent aggregation of MAVS, which promoted type I IFN production upon RNA virus infection. Consistently, mice with SLC25A23 knockdown were more resistant to RNA virus infection in vivo. These findings establish SLC25A23 as a novel regulator of MAVS posttranslational modifications and of type I antiviral immunity.
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Affiliation(s)
- Hongguang Zhang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Xin Li
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Yiwei Wang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Xianxian Liu
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Jing Guo
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Zheng Wang
- Department of Reproductive Medicine, The Affiliated Hospital of Qingdao University, Qingdao, China
- Department of Genetics and Cell Biology, Basic Medical College, Qingdao University, Qingdao, China
| | - Lulu Zhang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Sidong Xiong
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Chunsheng Dong
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
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Li J, Zhang R, Wang C, Zhu J, Ren M, Jiang Y, Hou X, Du Y, Wu Q, Qi S, Li L, Chen S, Yang H, Hou F. WDR77 inhibits prion-like aggregation of MAVS to limit antiviral innate immune response. Nat Commun 2023; 14:4824. [PMID: 37563140 PMCID: PMC10415273 DOI: 10.1038/s41467-023-40567-5] [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: 01/02/2023] [Accepted: 08/01/2023] [Indexed: 08/12/2023] Open
Abstract
RIG-I-MAVS signaling pathway plays a crucial role in defending against pathogen infection and maintaining immune balance. Upon detecting viral RNA, RIG-I triggers the formation of prion-like aggregates of the adaptor protein MAVS, which then activates the innate antiviral immune response. However, the mechanisms that regulate the aggregation of MAVS are not yet fully understood. Here, we identified WDR77 as a MAVS-associated protein, which negatively regulates MAVS aggregation. WDR77 binds to MAVS proline-rich region through its WD2-WD3-WD4 domain and inhibits the formation of prion-like filament of recombinant MAVS in vitro. In response to virus infection, WDR77 is recruited to MAVS to prevent the formation of its prion-like aggregates and thus downregulate RIG-I-MAVS signaling in cells. WDR77 deficiency significantly potentiates the induction of antiviral genes upon negative-strand RNA virus infections, and myeloid-specific Wdr77-deficient mice are more resistant to RNA virus infection. Our findings reveal that WDR77 acts as a negative regulator of the RIG-I-MAVS signaling pathway by inhibiting the prion-like aggregation of MAVS to prevent harmful inflammation.
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Affiliation(s)
- Jiaxin Li
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Rui Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Changwan Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
| | - Junyan Zhu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Miao Ren
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yingbo Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xianteng Hou
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yangting Du
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Qing Wu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Shishi Qi
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing, 102206, China
| | - She Chen
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Hui Yang
- Shanghai Key Laboratory of Brain Function Restoration and Neural Regeneration, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Fajian Hou
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, 200031, China.
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
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6
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Nagar A, Bharadwaj R, Shaikh MOF, Roy A. What are NLRP3-ASC specks? an experimental progress of 22 years of inflammasome research. Front Immunol 2023; 14:1188864. [PMID: 37564644 PMCID: PMC10411722 DOI: 10.3389/fimmu.2023.1188864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/12/2023] [Indexed: 08/12/2023] Open
Abstract
Speck assembly is the hallmark of NLRP3 inflammasome activation. The 1µm structure comprising of NLRP3 and ASC is the first observable phenotype of NLRP3 activation. While the common consensus is that the specks are the site of inflammasome activity, no direct experimental evidence exists to support this notion. In these 22 years, since the inflammasome discovery, several research studies have been published which directly or indirectly support or refute the idea of speck being the inflammasome. This review compiles the data from two decades of research to answer a long-standing question: "What are NLRP3-ASC specks?"
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Affiliation(s)
- Abhinit Nagar
- Department of Flow Cytometry, Cytek Biosciences, Fremont, CA, United States
| | - Ravi Bharadwaj
- MassBiologics of the University of Massachusetts Medical School, Boston, MA, United States
| | - Mohammad Omar Faruk Shaikh
- Division of Critical Care Medicine, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital, Boston, MA, United States
- Department of Anesthesia, Harvard Medical School, Boston, MA, United States
| | - Abhishek Roy
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
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7
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Liu D, Tan Q, Zhu J, Zhang Y, Xue Y, Song Y, Liu Y, Wang Q, Lai L. MicroRNA-33/33* inhibit the activation of MAVS through AMPK in antiviral innate immunity. Cell Mol Immunol 2021; 18:1450-1462. [PMID: 31767975 PMCID: PMC8167167 DOI: 10.1038/s41423-019-0326-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 10/19/2019] [Indexed: 02/07/2023] Open
Abstract
Innate immunity plays a prominent role in the host defense against pathogens and must be precisely regulated. As vital orchestrators in cholesterol homeostasis, microRNA-33/33* have been widely investigated in cellular metabolism. However, their role in antiviral innate immunity is largely unknown. Here, we report that VSV stimulation decreased the expression of miR-33/33* through an IFNAR-dependent manner in macrophages. Overexpression of miR-33/33* resulted in impaired RIG-I signaling, enhancing viral load and lethality whereas attenuating type I interferon production both in vitro and in vivo. In addition, miR-33/33* specifically prevented the mitochondrial adaptor mitochondrial antiviral-signaling protein (MAVS) from forming activated aggregates by targeting adenosine monophosphate activated protein kinase (AMPK), subsequently impeding the mitophagy-mediated elimination of damaged mitochondria and disturbing mitochondrial homeostasis which is indispensable for efficient MAVS activation. Our findings establish miR-33/33* as negative modulators of the RNA virus-triggered innate immune response and identify a previously unknown regulatory mechanism linking mitochondrial homeostasis with antiviral signaling pathways.
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Affiliation(s)
- Danhui Liu
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Qinchun Tan
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jie Zhu
- Department of Clinical Laboratory, Zhejiang Hospital, Hangzhou, 310030, China
| | - Yuanyuan Zhang
- The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, 310052, China
| | - Yue Xue
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yinjing Song
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yang Liu
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Qingqing Wang
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - Lihua Lai
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China.
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, 310058, China.
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8
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Abstract
Amyloids are β-sheet-rich protein polymers that can be pathological or display a variety of biological roles. In filamentous fungi, specific immune receptors activate programmed cell death execution proteins through a process of amyloid templating akin to prion propagation. In filamentous fungi, NLR-based signalosomes activate downstream membrane-targeting cell death-inducing proteins by a mechanism of amyloid templating. In the species Podospora anserina, two such signalosomes, NWD2/HET-S and FNT1/HELLF, have been described. An analogous system involving a distinct amyloid signaling motif, termed PP, was also identified in the genome of the species Chaetomium globosum and studied using heterologous expression in Podospora anserina. The PP motif bears resemblance to the RIP homotypic interaction motif (RHIM) and to RHIM-like motifs controlling necroptosis in mammals and innate immunity in flies. We identify here a third NLR signalosome in Podospora anserina comprising a PP motif and organized as a two-gene cluster encoding an NLR and an HELL domain cell death execution protein termed HELLP. We show that the PP motif region of HELLP forms a prion we term [π] and that [π] prions trigger the cell death-inducing activity of full-length HELLP. We detect no prion cross-seeding between HET-S, HELLF, and HELLP amyloid motifs. In addition, we find that, like PP motifs, RHIMs from human RIP1 and RIP3 kinases are able to form prions in Podospora and that [π] and [Rhim] prions partially cross-seed. Our study shows that Podospora anserina displays three independent cell death-inducing amyloid signalosomes. Based on the described functional similarity between RHIM and PP, it appears likely that these amyloid motifs constitute evolutionarily related cell death signaling modules.
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9
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Abstract
Amyloids are implicated in many protein misfolding diseases. Amyloid folds, however, also display a range of functional roles particularly in the microbial world. The templating ability of these folds endows them with specific properties allowing their self-propagation and protein-to-protein transmission in vivo. This property, the prion principle, is exploited by specific signaling pathways that use transmission of the amyloid fold as a way to convey information from a receptor to an effector protein. I describe here amyloid signaling pathways involving fungal nucleotide binding and oligomerization domain (NOD)-like receptors that were found to control nonself recognition and programmed cell death processes. Studies on these fungal amyloid signaling motifs stem from the characterization of the fungal [Het-s] prion protein and have led to the identification in fungi but also in multicellular bacteria of several distinct families of signaling motifs, one of which is related to RHIM [receptor-interacting protein (RIP) homotypic interaction motif], an amyloid motif regulating mammalian necroptosis.
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Affiliation(s)
- Sven J. Saupe
- Institut de Biochimie et de Génétique Cellulaire, UMR 5095 CNRS, Université de Bordeaux, 33077 Bordeaux CEDEX, France
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10
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Bu L, Wang H, Hou P, Guo S, He M, Xiao J, Li P, Zhong Y, Jia P, Cao Y, Liang G, Yang C, Chen L, Guo D, Li CM. The Ubiquitin E3 Ligase Parkin Inhibits Innate Antiviral Immunity Through K48-Linked Polyubiquitination of RIG-I and MDA5. Front Immunol 2020; 11:1926. [PMID: 32983119 PMCID: PMC7492610 DOI: 10.3389/fimmu.2020.01926] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/17/2020] [Indexed: 01/02/2023] Open
Abstract
Innate immunity is the first-line defense against antiviral or antimicrobial infection. RIG-I and MDA5, which mediate the recognition of pathogen-derived nucleic acids, are essential for production of type I interferons (IFN). Here, we identified mitochondrion depolarization inducer carbonyl cyanide 3-chlorophenylhydrazone (CCCP) inhibited the response and antiviral activity of type I IFN during viral infection. Furthermore, we found that the PTEN-induced putative kinase 1 (PINK1) and the E3 ubiquitin-protein ligase Parkin mediated mitophagy, thus negatively regulating the activation of RIG-I and MDA5. Parkin directly interacted with and catalyzed the K48-linked polyubiquitination and subsequent degradation of RIG-I and MDA5. Thus, we demonstrate that Parkin limits RLR-triggered innate immunity activation, suggesting Parkin as a potential therapeutic target for the control of viral infection.
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Affiliation(s)
- Lang Bu
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Huan Wang
- Institute of Precision Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Panpan Hou
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Shuting Guo
- Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Miao He
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Jingshu Xiao
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Ping Li
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Yongheng Zhong
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Penghui Jia
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Yuanyuan Cao
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Guanzhan Liang
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Chenwei Yang
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Lang Chen
- Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Deyin Guo
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
| | - Chun-Mei Li
- MOE Key Laboratory of Tropical Disease Control, the Infection and Immunity Center (TIIC), School of Medicine, Sun Yat-sen University, Shenzhen, China
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11
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Nil Z, Hervás R, Gerbich T, Leal P, Yu Z, Saraf A, Sardiu M, Lange JJ, Yi K, Unruh J, Slaughter B, Si K. Amyloid-like Assembly Activates a Phosphatase in the Developing Drosophila Embryo. Cell 2020; 178:1403-1420.e21. [PMID: 31491385 DOI: 10.1016/j.cell.2019.08.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/07/2019] [Accepted: 08/08/2019] [Indexed: 12/30/2022]
Abstract
Prion-like proteins can assume distinct conformational and physical states in the same cell. Sequence analysis suggests that prion-like proteins are prevalent in various species; however, it remains unclear what functional space they occupy in multicellular organisms. Here, we report the identification of a prion-like protein, Herzog (CG5830), through a multimodal screen in Drosophila melanogaster. Herzog functions as a membrane-associated phosphatase and controls embryonic patterning, likely being involved in TGF-β/BMP and FGF/EGF signaling pathways. Remarkably, monomeric Herzog is enzymatically inactive and becomes active upon amyloid-like assembly. The prion-like domain of Herzog is necessary for both its assembly and membrane targeting. Removal of the prion-like domain impairs activity, while restoring assembly on the membrane using a heterologous prion-like domain and membrane-targeting motif can restore phosphatase activity. This study provides an example of a prion-like domain that allows an enzyme to gain essential functionality via amyloid-like assembly to control animal development.
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Affiliation(s)
- Zelha Nil
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Rubén Hervás
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Therese Gerbich
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Paulo Leal
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Zulin Yu
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Anita Saraf
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Mihaela Sardiu
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Jeffrey J Lange
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Kexi Yi
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Jay Unruh
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Brian Slaughter
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA
| | - Kausik Si
- Stowers Institute for Medical Research, 1000E 50(th) Street, Kansas City, MO 64110, USA; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA.
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12
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Lau Y, Oamen HP, Caudron F. Protein Phase Separation during Stress Adaptation and Cellular Memory. Cells 2020; 9:cells9051302. [PMID: 32456195 PMCID: PMC7291175 DOI: 10.3390/cells9051302] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/14/2020] [Accepted: 05/21/2020] [Indexed: 12/13/2022] Open
Abstract
Cells need to organise and regulate their biochemical processes both in space and time in order to adapt to their surrounding environment. Spatial organisation of cellular components is facilitated by a complex network of membrane bound organelles. Both the membrane composition and the intra-organellar content of these organelles can be specifically and temporally controlled by imposing gates, much like bouncers controlling entry into night-clubs. In addition, a new level of compartmentalisation has recently emerged as a fundamental principle of cellular organisation, the formation of membrane-less organelles. Many of these structures are dynamic, rapidly condensing or dissolving and are therefore ideally suited to be involved in emergency cellular adaptation to stresses. Remarkably, the same proteins have also the propensity to adopt self-perpetuating assemblies which properties fit the needs to encode cellular memory. Here, we review some of the principles of phase separation and the function of membrane-less organelles focusing particularly on their roles during stress response and cellular memory.
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13
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RACK1 attenuates RLR antiviral signaling by targeting VISA-TRAF complexes. Biochem Biophys Res Commun 2018; 508:667-674. [PMID: 30527812 DOI: 10.1016/j.bbrc.2018.11.203] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 11/30/2018] [Indexed: 12/22/2022]
Abstract
Virus-induced signaling adaptor (VISA), which mediates the production of type I interferon, is crucial for the retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) signaling pathway. Upon viral infection, RIG-I recognizes double-stranded viral RNA and interacts with VISA to mediate antiviral innate immunity. However, the mechanisms underlying RIG/VISA-mediated antiviral regulation remain unclear. In this study, we confirmed that receptor for activated C kinase 1 (RACK1) interacts with VISA and attenuates the RIG/VISA-mediated antiviral innate immune signaling pathway. Overexpression of RACK1 inhibited the interferon-β (IFN-β) promoter; interferon-stimulated response element (ISRE); nuclear factor kappa B (NF-κB) activation; and dimerization of interferon regulatory factor 3 (IRF3) mediated by RIG-I, VISA, and TANK-binding kinase 1 (TBK1). A reduction in RACK1 expression level upon small interfering RNA knockdown increased RIG/VISA-mediated antiviral transduction. Additionally, RACK1 disrupted formation of the VISA-tumor necrosis factor receptor-associated factor 2 (TRAF2), VISA-TRAF3, and VISA-TRAF6 complexes during RIG-I/VISA-mediated signal transduction. Additionally, RACK1 enhanced K48-linked ubiquitination of VISA, attenuated its K63-linked ubiquitination, and decreased VISA-mediated antiviral signal transduction. Together, these results indicate that RACK1 interacts with VISA to repress downstream signaling and downregulates virus-induced IFN-β production in the RIG-I/VISA signaling pathway.
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14
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Abstract
Inflammasomes are the central signaling hubs of the inflammatory response. They process cytosolic evidence of infection, cell damage, or metabolic disturbances, and elicit a pro-inflammatory response mediated by members of the interleukin-1 family of cytokines and pyroptotoic cell death. On the molecular level, this is accomplished by the sensor-nucleated recruitment and oligomerization of the adapter protein ASC. Once a tunable threshold is reached, cooperative assembly of ASC into linear filaments and their condensation into macromolecular ASC specks promotes an all-or-none response. These structures are highly regulated and provide a unique signaling platform or compartment to control the activity of caspase-1 and likely other effectors. Emerging evidence indicates that ASC specks are also released from inflammasome-activated cells and accumulate in inflamed tissues, where they can continue to mature cytokines or be internalized by surrounding cells to further nucleate ASC specks in their cytosol. Little is known about the mechanisms governing ASC speck release, uptake, and endosomal escape, as well as its contribution to inflammation and disease. Here, we describe the different outcomes of inflammasome activation and discuss the potential function of extracellular ASC specks. We highlight gaps in our understanding of this central process of inflammation, which may have direct consequences on the modulation of host responses and chronic inflammation.
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Affiliation(s)
- Bernardo S Franklin
- Institute of Innate Immunity, University Hospitals, University of Bonn, Bonn, Germany
| | - Eicke Latz
- Institute of Innate Immunity, University Hospitals, University of Bonn, Bonn, Germany.,Department of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA, USA.,German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Florian Ingo Schmidt
- Institute of Innate Immunity, University Hospitals, University of Bonn, Bonn, Germany
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15
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Cancer therapies activate RIG-I-like receptor pathway through endogenous non-coding RNAs. Oncotarget 2018; 7:26496-515. [PMID: 27034163 PMCID: PMC5041995 DOI: 10.18632/oncotarget.8420] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 03/05/2016] [Indexed: 12/14/2022] Open
Abstract
Emerging evidence indicates that ionizing radiation (IR) and chemotherapy activate Type I interferon (IFN) signaling in tumor and host cells. However, the mechanism of induction is poorly understood. We identified a novel radioprotective role for the DEXH box RNA helicase LGP2 (DHX58) through its suppression of IR-induced cytotoxic IFN-beta [1]. LGP2 inhibits activation of the RIG-I-like receptor (RLR) pathway upon binding of viral RNA to the cytoplasmic sensors RIG-I (DDX58) and MDA5 (IFIH1) and subsequent IFN signaling via the mitochondrial adaptor protein MAVS (IPS1). Here we show that MAVS is necessary for IFN-beta induction and interferon-stimulated gene expression in the response to IR. Suppression of MAVS conferred radioresistance in normal and cancer cells. Germline deletion of RIG-I, but not MDA5, protected mice from death following total body irradiation, while deletion of LGP2 accelerated the death of irradiated animals. In human tumors depletion of RIG-I conferred resistance to IR and different classes of chemotherapy drugs. Mechanistically, IR stimulated the binding of cytoplasmic RIG-I with small endogenous non-coding RNAs (sncRNAs), which triggered IFN-beta activity. We demonstrate that the small nuclear RNAs U1 and U2 translocate to the cytoplasm after IR treatment, thus stimulating the formation of RIG-I: RNA complexes and initiating downstream signaling events. Taken together, these findings suggest that the physiologic responses to radio-/chemo-therapy converge on an antiviral program in recruitment of the RLR pathway by a sncRNA-dependent activation of RIG-I which commences cytotoxic IFN signaling. Importantly, activation of interferon genes by radiation or chemotherapy is associated with a favorable outcome in patients undergoing treatment for cancer. To our knowledge, this is the first demonstration of a cell-intrinsic response to clinically relevant genotoxic treatments mediated by an RNA-dependent mechanism.
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16
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Abstract
This review introduces recent concepts in innate immunity highlighting some of the latest exciting findings. These include: the discovery of the initiator of pyroptosis, Gasdermin D, and mechanisms of inflammatory caspases in innate immune signaling; the formation of oligomeric signalosomes downstream of innate immune receptors; mechanisms that shape innate immune responses, such as cellular homeostasis, cell metabolism, and pathogen viability; rapid methods of cell-to-cell communication; the interplay between the host and its microbiome and the concept of innate immunological memory. Furthermore, we discuss open questions and illustrate how technological advances, such as CRISPR/Cas9, may provide important answers for outstanding questions in the field of innate immunity.
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Affiliation(s)
- Karin Pelka
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Dominic De Nardo
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia. .,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia.
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17
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Shao WH, Shu DH, Zhen Y, Hilliard B, Priest SO, Cesaroni M, Ting JPY, Cohen PL. Prion-like Aggregation of Mitochondrial Antiviral Signaling Protein in Lupus Patients Is Associated With Increased Levels of Type I Interferon. Arthritis Rheumatol 2017; 68:2697-2707. [PMID: 27110677 DOI: 10.1002/art.39733] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 04/21/2016] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Increased levels of type I interferon (IFN) and type I IFN-regulated genes are found in patients with systemic lupus erythematosus (SLE) and may be central to its pathogenesis. Mitochondrial antiviral signaling protein (MAVS) is a key regulator of type I IFN that undergoes a dramatic prion-like aggregation and self propagates the activation signal from viral RNA to amplify downstream IFN production. We undertook this study to determine whether such MAVS aggregates might play a role in the sustained increased production of type I IFN in SLE. METHODS Peripheral blood mononuclear cells were isolated and mitochondrial extracts were prepared. MAVS aggregation was detected by semidenatured agarose gel electrophoresis and confirmed by immunofluorescence staining. MAVS-associated signaling proteins were analyzed by Western blotting. MAVS aggregation-associated gene expression signature was analyzed by microarray. RESULTS In blood cells from 22 of 67 SLE patients, essentially all MAVS was in a high molecular weight aggregated form. None of 6 rheumatoid arthritis patients and only 3 of 33 healthy controls had abnormal MAVS. Compared to MAVS aggregate-negative patients, MAVS aggregate-positive SLE patients had significantly higher serum levels of IFNβ and significantly increased levels of autoantibodies against Sm and U1 RNP. Gene array data revealed a characteristic gene expression pattern in these patients, with altered expression of genes involved in IFN signaling and membrane trafficking. CONCLUSION Persistent MAVS aggregates may lead to increased type I IFN production and result in unmitigated signals leading to autoimmunity.
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Affiliation(s)
- Wen-Hai Shao
- Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania.
| | - Daniel H Shu
- Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Yuxuan Zhen
- Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Brendan Hilliard
- Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Stephen O Priest
- Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Matteo Cesaroni
- Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | | | - Philip L Cohen
- Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania.
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18
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Zhang Y, Li H. Reprogramming Interferon Regulatory Factor Signaling in Cardiometabolic Diseases. Physiology (Bethesda) 2017; 32:210-223. [PMID: 28404737 DOI: 10.1152/physiol.00038.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/06/2017] [Accepted: 02/09/2017] [Indexed: 01/12/2023] Open
Abstract
Interferon regulatory factors (IRFs) are evolutionarily conserved proteins expressed not only in immune cells but also in other tissues and organs outside the immune system. In this review, we discuss mechanisms responsible for IRF-mediated innate immune responses and the function and mechanism of IRFs in cardiometabolic diseases. We focus on the role of IRFs in innate immunity and cardiometabolic homeostasis, and highlight reprogrammed IRF signaling.
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Affiliation(s)
- Yaxing Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, People's Republic of China
- Institute of Model Animal, Wuhan University, Wuhan, People's Republic of China; and
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, People's Republic of China
| | - Hongliang Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, People's Republic of China
- Institute of Model Animal, Wuhan University, Wuhan, People's Republic of China; and
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, People's Republic of China
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19
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Zinc-Induced Polymerization of Killer-Cell Ig-like Receptor into Filaments Promotes Its Inhibitory Function at Cytotoxic Immunological Synapses. Mol Cell 2016; 62:21-33. [PMID: 27058785 DOI: 10.1016/j.molcel.2016.03.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 01/29/2016] [Accepted: 03/07/2016] [Indexed: 11/22/2022]
Abstract
The inhibitory function of killer cell immunoglobulin-like receptors (KIR) that bind HLA-C and block activation of human natural killer (NK) cells is dependent on zinc. We report that zinc induced the assembly of soluble KIR into filamentous polymers, as detected by electron microscopy, which depolymerized after zinc chelation. Similar KIR filaments were isolated from lysates of cells treated with zinc, and membrane protrusions enriched in zinc were detected on whole cells by scanning electron microscopy and imaging mass spectrometry. Two independent mutations in the extracellular domain of KIR, away from the HLA-C binding site, impaired zinc-driven polymerization and inhibitory function. KIR filaments formed spontaneously, without the addition of zinc, at functional inhibitory immunological synapses of NK cells with HLA-C(+) cells. Adding to the recent paradigm of signal transduction through higher order molecular assemblies, zinc-induced polymerization of inhibitory KIR represents an unusual mode of signaling by a receptor at the cell surface.
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20
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Sanchez JG, Chiang JJ, Sparrer KMJ, Alam SL, Chi M, Roganowicz MD, Sankaran B, Gack MU, Pornillos O. Mechanism of TRIM25 Catalytic Activation in the Antiviral RIG-I Pathway. Cell Rep 2016; 16:1315-1325. [PMID: 27425606 PMCID: PMC5076470 DOI: 10.1016/j.celrep.2016.06.070] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 05/11/2016] [Accepted: 06/16/2016] [Indexed: 12/25/2022] Open
Abstract
Antiviral response pathways induce interferon by higher-order assembly of signaling complexes called signalosomes. Assembly of the RIG-I signalosome is regulated by K63-linked polyubiquitin chains, which are synthesized by the E3 ubiquitin ligase, TRIM25. We have previously shown that the TRIM25 coiled-coil domain is a stable, antiparallel dimer that positions two catalytic RING domains on opposite ends of an elongated rod. We now show that the RING domain is a separate self-association motif that engages ubiquitin-conjugated E2 enzymes as a dimer. RING dimerization is required for catalysis, TRIM25-mediated RIG-I ubiquitination, interferon induction, and antiviral activity. We also provide evidence that RING dimerization and E3 ligase activity are promoted by binding of the TRIM25 SPRY domain to the RIG-I effector domain. These results indicate that TRIM25 actively participates in higher-order assembly of the RIG-I signalosome and helps to fine-tune the efficiency of the RIG-I-mediated antiviral response.
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Affiliation(s)
- Jacint G Sanchez
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - Jessica J Chiang
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Steven L Alam
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Michael Chi
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - Marcin D Roganowicz
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - Banumathi Sankaran
- Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Michaela U Gack
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Department of Microbiology, University of Chicago, Chicago, IL 60637, USA.
| | - Owen Pornillos
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.
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21
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Sanders DW, Kaufman SK, Holmes BB, Diamond MI. Prions and Protein Assemblies that Convey Biological Information in Health and Disease. Neuron 2016; 89:433-48. [PMID: 26844828 DOI: 10.1016/j.neuron.2016.01.026] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Prions derived from the prion protein (PrP) were first characterized as infectious agents that transmit pathology between individuals. However, the majority of cases of neurodegeneration caused by PrP prions occur sporadically. Proteins that self-assemble as cross-beta sheet amyloids are a defining pathological feature of infectious prion disorders and all major age-associated neurodegenerative diseases. In fact, multiple non-infectious proteins exhibit properties of template-driven self-assembly that are strikingly similar to PrP. Evidence suggests that like PrP, many proteins form aggregates that propagate between cells and convert cognate monomer into ordered assemblies. We now recognize that numerous proteins assemble into macromolecular complexes as part of normal physiology, some of which are self-amplifying. This review highlights similarities among infectious and non-infectious neurodegenerative diseases associated with prions, emphasizing the normal and pathogenic roles of higher-order protein assemblies. We propose that studies of the structural and cellular biology of pathological versus physiological aggregates will be mutually informative.
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Affiliation(s)
- David W Sanders
- Center for Alzheimer's and Neurodegenerative Diseases, UT Southwestern Medical Center, Dallas, TX 75390, USA; Program in Neuroscience, Washington University School of Medicine in St. Louis, St. Louis, MO 63130, USA
| | - Sarah K Kaufman
- Center for Alzheimer's and Neurodegenerative Diseases, UT Southwestern Medical Center, Dallas, TX 75390, USA; Program in Neuroscience, Washington University School of Medicine in St. Louis, St. Louis, MO 63130, USA
| | - Brandon B Holmes
- Center for Alzheimer's and Neurodegenerative Diseases, UT Southwestern Medical Center, Dallas, TX 75390, USA; Program in Neuroscience, Washington University School of Medicine in St. Louis, St. Louis, MO 63130, USA
| | - Marc I Diamond
- Center for Alzheimer's and Neurodegenerative Diseases, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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22
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Giles K, Berry DB, Condello C, Dugger BN, Li Z, Oehler A, Bhardwaj S, Elepano M, Guan S, Silber BM, Olson SH, Prusiner SB. Optimization of Aryl Amides that Extend Survival in Prion-Infected Mice. J Pharmacol Exp Ther 2016; 358:537-47. [PMID: 27317802 DOI: 10.1124/jpet.116.235556] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 06/16/2016] [Indexed: 11/22/2022] Open
Abstract
Developing therapeutics for neurodegenerative diseases (NDs) prevalent in the aging population remains a daunting challenge. With the growing understanding that many NDs progress by conformational self-templating of specific proteins, the prototypical prion diseases offer a platform for ND drug discovery. We evaluated high-throughput screening hits with the aryl amide scaffold and explored the structure-activity relationships around three series differing in their N-aryl core: benzoxazole, benzothiazole, and cyano. Potent anti-prion compounds were advanced to pharmacokinetic studies, and the resulting brain-penetrant leads from each series, together with a related N-aryl piperazine lead, were escalated to long-term dosing and efficacy studies. Compounds from each of the four series doubled the survival of mice infected with a mouse-passaged prion strain. Treatment with aryl amides altered prion strain properties, as evidenced by the distinct patterns of neuropathological deposition of prion protein and associated astrocytic gliosis in the brain; however, none of the aryl amide compounds resulted in drug-resistant prion strains, in contrast to previous studies on compounds with the 2-aminothiazole (2-AMT) scaffold. As seen with 2-AMTs and other effective anti-prion compounds reported to date, the novel aryl amides reported here were ineffective in prolonging the survival of transgenic mice infected with human prions. Most encouraging is our discovery that aryl amides show that the development of drug resistance is not an inevitable consequence of efficacious anti-prion therapeutics.
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Affiliation(s)
- Kurt Giles
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - David B Berry
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Carlo Condello
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Brittany N Dugger
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Zhe Li
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Abby Oehler
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Sumita Bhardwaj
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Manuel Elepano
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Shenheng Guan
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - B Michael Silber
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Steven H Olson
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
| | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases (K.G., D.B.B., C.C., B.N.D., Z.L., A.O., S.B., M.E., S.G., B.M.S., S.H.O., S.B.P.) and Departments of Neurology (K.G., C.C., B.N.D., Z.L., B.M.S., S.H.O., S.B.P.), Pharmaceutical Chemistry (S.G.), Bioengineering and Therapeutic Sciences (B.M.S.), and Biochemistry and Biophysics (S.B.P.), University of California, San Francisco, California
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23
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Gambin Y, Polinkovsky M, Francois B, Giles N, Bhumkar A, Sierecki E. Confocal Spectroscopy to Study Dimerization, Oligomerization and Aggregation of Proteins: A Practical Guide. Int J Mol Sci 2016; 17:ijms17050655. [PMID: 27144560 PMCID: PMC4881481 DOI: 10.3390/ijms17050655] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/15/2016] [Accepted: 04/20/2016] [Indexed: 12/25/2022] Open
Abstract
Protein self-association is a key feature that can modulate the physiological role of proteins or lead to deleterious effects when uncontrolled. Protein oligomerization is a simple way to modify the activity of a protein, as the modulation of binding interfaces allows for self-activation or inhibition, or variation in the selectivity of binding partners. As such, dimerization and higher order oligomerization is a common feature in signaling proteins, for example, and more than 70% of enzymes have the potential to self-associate. On the other hand, protein aggregation can overcome the regulatory mechanisms of the cell and can have disastrous physiological effects. This is the case in a number of neurodegenerative diseases, where proteins, due to mutation or dysregulation later in life, start polymerizing and often fibrillate, leading to the creation of protein inclusion bodies in cells. Dimerization, well-defined oligomerization and random aggregation are often difficult to differentiate and characterize experimentally. Single molecule “counting” methods are particularly well suited to the study of self-oligomerization as they allow observation and quantification of behaviors in heterogeneous conditions. However, the extreme dilution of samples often causes weak complexes to dissociate, and rare events can be overlooked. Here, we discuss a straightforward alternative where the principles of single molecule detection are used at higher protein concentrations to quantify oligomers and aggregates in a background of monomers. We propose a practical guide for the use of confocal spectroscopy to quantify protein oligomerization status and also discuss about its use in monitoring changes in protein aggregation in drug screening assays.
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Affiliation(s)
- Yann Gambin
- EMBL Australia Node in Single Molecule Sciences, School of Medical Science, the University of New South Wales, Sydney, NSW 2052, Australia.
| | - Mark Polinkovsky
- EMBL Australia Node in Single Molecule Sciences, School of Medical Science, the University of New South Wales, Sydney, NSW 2052, Australia.
| | - Bill Francois
- EMBL Australia Node in Single Molecule Sciences, School of Medical Science, the University of New South Wales, Sydney, NSW 2052, Australia.
| | - Nichole Giles
- EMBL Australia Node in Single Molecule Sciences, School of Medical Science, the University of New South Wales, Sydney, NSW 2052, Australia.
| | - Akshay Bhumkar
- EMBL Australia Node in Single Molecule Sciences, School of Medical Science, the University of New South Wales, Sydney, NSW 2052, Australia.
| | - Emma Sierecki
- EMBL Australia Node in Single Molecule Sciences, School of Medical Science, the University of New South Wales, Sydney, NSW 2052, Australia.
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24
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Pallarès I, Iglesias V, Ventura S. The Rho Termination Factor of Clostridium botulinum Contains a Prion-Like Domain with a Highly Amyloidogenic Core. Front Microbiol 2016; 6:1516. [PMID: 26779170 PMCID: PMC4703818 DOI: 10.3389/fmicb.2015.01516] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 12/16/2015] [Indexed: 11/27/2022] Open
Abstract
Prion-like proteins can switch between a soluble intrinsically disordered conformation and a highly ordered amyloid assembly. This conformational promiscuity is encoded in specific sequence regions, known as prion domains (PrDs). Prions are best known as the causative factors of neurological diseases in mammals. However, bioinformatics analyses reveal that proteins bearing PrDs are present in all kingdoms of life, including bacteria, thus supporting the idea that they serve conserved beneficial cellular functions. Despite the proportion of predicted prion-like proteins in bacterial proteomes is generally low, pathogenic species seem to have a higher prionic load, suggesting that these malleable proteins may favor pathogenic traits. In the present work, we performed a stringent computational analysis of the Clostridium botulinum pathogen proteome in the search for prion-like proteins. A total of 54 candidates were predicted for this anaerobic bacterium, including the transcription termination Rho factor. This RNA-binding protein has been shown to play a crucial role in bacterial adaptation to changing environments. We show here that the predicted disordered PrD domain of this RNA-binding protein contains an inner, highly polar, asparagine-rich short sequence able to spontaneously self-assemble into amyloid-like structures, bearing thus the potential to induce a Rho factor conformational switch that might rewire gene expression in response to environmental conditions.
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Affiliation(s)
- Irantzu Pallarès
- Institut de Biotecnologia i Biomedicina and Departament de Bioquìmica i Biologia Molecular, Universitat Autònoma de Barcelona Barcelona, Spain
| | - Valentin Iglesias
- Institut de Biotecnologia i Biomedicina and Departament de Bioquìmica i Biologia Molecular, Universitat Autònoma de Barcelona Barcelona, Spain
| | - Salvador Ventura
- Institut de Biotecnologia i Biomedicina and Departament de Bioquìmica i Biologia Molecular, Universitat Autònoma de Barcelona Barcelona, Spain
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25
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Affiliation(s)
- Kausik Si
- Stowers Institute for Medical Research, Kansas City, Missouri 64110;
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26
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Hu Z, Zhou Q, Zhang C, Fan S, Cheng W, Zhao Y, Shao F, Wang HW, Sui SF, Chai J. Structural and biochemical basis for induced self-propagation of NLRC4. Science 2015; 350:399-404. [PMID: 26449475 DOI: 10.1126/science.aac5489] [Citation(s) in RCA: 237] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 09/14/2015] [Indexed: 02/05/2023]
Abstract
Responding to stimuli, nucleotide-binding domain and leucine-rich repeat-containing proteins (NLRs) oligomerize into multiprotein complexes, termed inflammasomes, mediating innate immunity. Recognition of bacterial pathogens by NLR apoptosis inhibitory proteins (NAIPs) induces NLR family CARD domain-containing protein 4 (NLRC4) activation and formation of NAIP-NLRC4 inflammasomes. The wheel-like structure of a PrgJ-NAIP2-NLRC4 complex determined by cryogenic electron microscopy at 6.6 angstrom reveals that NLRC4 activation involves substantial structural reorganization that creates one oligomerization surface (catalytic surface). Once activated, NLRC4 uses this surface to catalyze the activation of an inactive NLRC4, self-propagating its active conformation to form the wheel-like architecture. NAIP proteins possess a catalytic surface matching the other oligomerization surface (receptor surface) of NLRC4 but not those of their own, ensuring that one NAIP is sufficient to initiate NLRC4 oligomerization.
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Affiliation(s)
- Zehan Hu
- Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiang Zhou
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Chenlu Zhang
- Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shilong Fan
- Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Cheng
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu, China
| | - Yue Zhao
- National Institute of Biological Sciences, Beijing 102206, China
| | - Feng Shao
- National Institute of Biological Sciences, Beijing 102206, China
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Sen-Fang Sui
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
| | - Jijie Chai
- Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China.
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27
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Yeast prions: Paramutation at the protein level? Semin Cell Dev Biol 2015; 44:51-61. [DOI: 10.1016/j.semcdb.2015.08.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 08/18/2015] [Indexed: 11/20/2022]
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28
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Du J, Zhang D, Zhang W, Ouyang G, Wang J, Liu X, Li S, Ji W, Liu W, Xiao W. pVHL Negatively Regulates Antiviral Signaling by Targeting MAVS for Proteasomal Degradation. THE JOURNAL OF IMMUNOLOGY 2015; 195:1782-90. [PMID: 26179906 DOI: 10.4049/jimmunol.1500588] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/16/2015] [Indexed: 12/25/2022]
Abstract
The von Hippel-Lindau (VHL) gene is a well-defined tumor suppressor linked to human heredity cancer syndromes. As a component of the VHL-elongin B/C E3 ligase complex, pVHL performs its tumor function by targeting proteins for proteasomal degradation. It is largely unknown whether pVHL functions in antiviral immunity. In this article, we identify that pVHL negatively regulates innate antiviral immunity, which acts mainly by inducing degradation of mitochondrial antiviral-signaling protein (MAVS, also known as Cardif, IPS-1, or VISA). Overexpression of pVHL abrogated the cellular response to viral infection, whereas knockdown of pVHL exerted the opposite effect. pVHL targeted the K420 residue of MAVS to catalyze the formation of K48-linked polyubiquitin chains, leading to proteasomal degradation of MAVS. After viral infection, Mavs levels remained low in wild type zebrafish embryos but became much higher in vhl-deficient (vhl(-/-)) zebrafish embryos. Higher MAVS levels correlated with a greatly exaggerated antiviral response. In this work, we demonstrate that pVHL exhibits a previously unknown role in innate antiviral immunity.
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Affiliation(s)
- Juan Du
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and
| | - Dawei Zhang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and
| | - Wei Zhang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and
| | - Gang Ouyang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and
| | - Jing Wang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and
| | - Xing Liu
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and
| | - Shun Li
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and
| | - Wei Ji
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and
| | - Wei Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Wuhan Xiao
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
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29
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De Nardo D. Toll-like receptors: Activation, signalling and transcriptional modulation. Cytokine 2015; 74:181-9. [PMID: 25846205 DOI: 10.1016/j.cyto.2015.02.025] [Citation(s) in RCA: 289] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 02/26/2015] [Indexed: 02/06/2023]
Abstract
Families of innate immune receptors serve as the bodies primary defence system by recognising and rapidly responding to infection by microorganisms or to endogenous danger signals and initiating inflammatory processes. Whilst Toll-like receptors (TLRs) were the first family to be discovered, important and exciting discoveries continue to emerge into the molecular mechanisms that control their activation and regulation. Herein, I will provide an overview of TLR activation and their downstream signalling cascades, and discuss some of the recent findings concerning the assembly of a TLR oligomeric signalling platform, known as the Myddosome. Further, a brief examination of the importance of crosstalk between multiple TLRs or between TLRs and other innate immune receptors for appropriate and coordinated immune responses will be presented. Finally, I will discuss the importance of mechanisms that regulate TLRs with a focus on the role of activating transcription factor 3 (ATF3) in modulating transcriptional responses downstream of TLRs.
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Affiliation(s)
- Dominic De Nardo
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3050, Australia.
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