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Xie J, Cheng J, Ko H, Tang Y. Cytosolic DNA sensors in neurodegenerative diseases: from physiological defenders to pathological culprits. EMBO Mol Med 2024; 16:678-699. [PMID: 38467840 PMCID: PMC11018843 DOI: 10.1038/s44321-024-00046-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 02/13/2024] [Accepted: 02/19/2024] [Indexed: 03/13/2024] Open
Abstract
Cytosolic DNA sensors are a group of pattern recognition receptors (PRRs) that vary in structures, molecular mechanisms, and origins but share a common function to detect intracellular microbial DNA and trigger the innate immune response like type 1 interferon production and autophagy. Cytosolic DNA sensors have been proven as indispensable defenders against the invasion of many pathogens; however, growing evidence shows that self-DNA misplacement to cytoplasm also frequently occurs in non-infectious circumstances. Accumulation of cytosolic DNA causes improper activation of cytosolic DNA sensors and triggers an abnormal autoimmune response, that significantly promotes pathological progression. Neurodegenerative diseases are a group of neurological disorders characterized by neuron loss and still lack effective treatments due to a limited understanding of pathogenesis. But current research has found a solid relationship between neurodegenerative diseases and cytosolic DNA sensing pathways. This review summarizes profiles of several major cytosolic DNA sensors and their common adaptor protein STING. It also discusses both the beneficial and detrimental roles of cytosolic DNA sensors in the genesis and progression of neurodegenerative diseases.
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Affiliation(s)
- Jiatian Xie
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China
- Brain Research Center, Sun Yat-sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, 510120, China
- Nanhai Translational Innovation Center of Precision Immunology, Sun Yat-sen Memorial Hospital, Foshan, 528200, China
| | - Jinping Cheng
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China
- Brain Research Center, Sun Yat-sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, 510120, China
- Nanhai Translational Innovation Center of Precision Immunology, Sun Yat-sen Memorial Hospital, Foshan, 528200, China
| | - Ho Ko
- Division of Neurology, Department of Medicine and Therapeutics & Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Yamei Tang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China.
- Brain Research Center, Sun Yat-sen Memorial Hospital, Sun Yat‑sen University, Guangzhou, 510120, China.
- Nanhai Translational Innovation Center of Precision Immunology, Sun Yat-sen Memorial Hospital, Foshan, 528200, China.
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2
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Glück IM, Mathias GP, Strauss S, Rat V, Gialdini I, Ebert TS, Stafford C, Agam G, Manley S, Hornung V, Jungmann R, Sieben C, Lamb DC. Nanoscale organization of the endogenous ASC speck. iScience 2023; 26:108382. [PMID: 38047065 PMCID: PMC10690566 DOI: 10.1016/j.isci.2023.108382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 06/15/2023] [Accepted: 10/31/2023] [Indexed: 12/05/2023] Open
Abstract
The NLRP3 inflammasome is a central component of the innate immune system. Its activation leads to formation of the ASC speck, a supramolecular assembly of the inflammasome adaptor protein ASC. Different models, based on ASC overexpression, have been proposed for the structure of the ASC speck. Using dual-color 3D super-resolution imaging (dSTORM and DNA-PAINT), we visualized the ASC speck structure following NLRP3 inflammasome activation using endogenous ASC expression. A complete structure was only obtainable by labeling with both anti-ASC antibodies and nanobodies. The complex varies in diameter between ∼800 and 1000 nm, and is composed of a dense core with emerging filaments. Dual-color confocal fluorescence microscopy indicated that the ASC speck does not colocalize with the microtubule-organizing center at late time points after Nigericin stimulation. From super-resolution images of whole cells, the ASC specks were sorted into a pseudo-time sequence indicating that they become denser but not larger during formation.
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Affiliation(s)
- Ivo M. Glück
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Grusha Primal Mathias
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Sebastian Strauss
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Virgile Rat
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Irene Gialdini
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Thomas Sebastian Ebert
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Che Stafford
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Ganesh Agam
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
| | - Suliana Manley
- Laboratory of Experimental Biophysics, École Polytechnique Fédérale de Lausanne, BSP 427 (Cubotron UNIL), Rte de la Sorge, CH-1015 Lausanne, Switzerland
| | - Veit Hornung
- Max Planck Institute of Biochemistry, Martinsried, Germany
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Ralf Jungmann
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Christian Sieben
- Laboratory of Experimental Biophysics, École Polytechnique Fédérale de Lausanne, BSP 427 (Cubotron UNIL), Rte de la Sorge, CH-1015 Lausanne, Switzerland
| | - Don C. Lamb
- Department of Chemistry, Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
- Center for Nano Science (CENS), Ludwig Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany
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3
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Ortega MA, De Leon-Oliva D, García-Montero C, Fraile-Martinez O, Boaru DL, de Castro AV, Saez MA, Lopez-Gonzalez L, Bujan J, Alvarez-Mon MA, García-Honduvilla N, Diaz-Pedrero R, Alvarez-Mon M. Reframing the link between metabolism and NLRP3 inflammasome: therapeutic opportunities. Front Immunol 2023; 14:1232629. [PMID: 37545507 PMCID: PMC10402745 DOI: 10.3389/fimmu.2023.1232629] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 07/04/2023] [Indexed: 08/08/2023] Open
Abstract
Inflammasomes are multiprotein signaling platforms in the cytosol that senses exogenous and endogenous danger signals and respond with the maturation and secretion of IL-1β and IL-18 and pyroptosis to induce inflammation and protect the host. The inflammasome best studied is the Nucleotide-binding oligomerization domain, leucine-rich repeat-containing family pyrin domain containing 3 (NLRP3) inflammasome. It is activated in a two-step process: the priming and the activation, leading to sensor NLRP3 oligomerization and recruitment of both adaptor ASC and executioner pro-caspase 1, which is activated by cleavage. Moreover, NLRP3 inflammasome activation is regulated by posttranslational modifications, including ubiquitination/deubiquitination, phosphorylation/dephosphorylation, acetylation/deacetylation, SUMOylation and nitrosylation, and interaction with NLPR3 protein binding partners. Moreover, the connection between it and metabolism is receiving increasing attention in this field. In this review, we present the structure, functions, activation, and regulation of NLRP3, with special emphasis on regulation by mitochondrial dysfunction-mtROS production and metabolic signals, i.e., metabolites as well as enzymes. By understanding the regulation of NLRP3 inflammasome activation, specific inhibitors can be rationally designed for the treatment and prevention of various immune- or metabolic-based diseases. Lastly, we review current NLRP3 inflammasome inhibitors and their mechanism of action.
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Affiliation(s)
- Miguel A. Ortega
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
| | - Diego De Leon-Oliva
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
| | - Cielo García-Montero
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
| | - Oscar Fraile-Martinez
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
| | - Diego Liviu Boaru
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
| | - Amador Velazquez de Castro
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
| | - Miguel A. Saez
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
- Pathological Anatomy Service, Central University Hospital of Defence-University of Alcalá (UAH) Madrid, Alcala de Henares, Spain
| | - Laura Lopez-Gonzalez
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
- Department of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, University of Alcalá, Alcala de Henares, Spain
| | - Julia Bujan
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
| | - Miguel Angel Alvarez-Mon
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
- Department of Psychiatry and Mental Health, Hospital Universitario Infanta Leonor, Madrid, Spain
| | - Natalio García-Honduvilla
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
| | - Raul Diaz-Pedrero
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
- Department of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, University of Alcalá, Alcala de Henares, Spain
- Department of General and Digestive Surgery, University Hospital Príncipe de Asturias, Madrid, Spain
| | - Melchor Alvarez-Mon
- Department of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- Ramón y Cajal Institute of Sanitary Research (IRYCIS), Madrid, Spain
- Immune System Diseases-Rheumatology and Internal Medicine Service, University Hospital Príncipe de Asturias, CIBEREHD, Alcalá de Henares, Spain
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4
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de Almeida L, Devi S, Indramohan M, Huang QQ, Ratsimandresy RA, Pope RM, Dorfleutner A, Stehlik C. POP1 inhibits MSU-induced inflammasome activation and ameliorates gout. Front Immunol 2022; 13:912069. [PMID: 36225929 PMCID: PMC9550078 DOI: 10.3389/fimmu.2022.912069] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 09/06/2022] [Indexed: 01/13/2023] Open
Abstract
Canonical inflammasomes are innate immune protein scaffolds that enable the activation of inflammatory caspase-1, and subsequently the processing and release of interleukin (IL)-1β, IL-18, and danger signals, as well as the induction of pyroptotic cell death. Inflammasome assembly and activation occurs in response to sensing of infectious, sterile and self-derived molecular patterns by cytosolic pattern recognition receptors, including the Nod-like receptor NLRP3. While these responses are essential for host defense, excessive and uncontrolled NLRP3 inflammasome responses cause and contribute to a wide spectrum of inflammatory diseases, including gout. A key step in NLRP3 inflammasome assembly is the sequentially nucleated polymerization of Pyrin domain (PYD)- and caspase recruitment domain (CARD)-containing inflammasome components. NLRP3 triggers polymerization of the adaptor protein ASC through PYD-PYD interactions, but ASC polymerization then proceeds in a self-perpetuating manner and represents a point of no return, which culminates in the activation of caspase-1 by induced proximity. In humans, small PYD-only proteins (POPs) lacking an effector domain regulate this key process through competitive binding, but limited information exists on their physiological role during health and disease. Here we demonstrate that POP1 expression in macrophages is sufficient to dampen MSU crystal-mediated inflammatory responses in animal models of gout. Whether MSU crystals are administered into a subcutaneous airpouch or into the ankle joint, the presence of POP1 significantly reduces neutrophil infiltration. Also, airpouch exudates have much reduced IL-1β and ASC, which are typical pro-inflammatory indicators that can also be detected in synovial fluids of gout patients. Exogenous expression of POP1 in mouse and human macrophages also blocks MSU crystal-induced NLRP3 inflammasome assembly, resulting in reduced IL-1β and IL-18 secretion. Conversely, reduced POP1 expression in human macrophages enhances IL-1β secretion. We further determined that the mechanism for the POP1-mediated inhibition of NLRP3 inflammasome activation is through its interference with the crucial NLRP3 and ASC interaction within the inflammasome complex. Strikingly, administration of an engineered cell permeable version of POP1 was able to ameliorate MSU crystal-mediated inflammation in vivo, as measured by neutrophil infiltration. Overall, we demonstrate that POP1 may play a crucial role in regulating inflammatory responses in gout.
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Affiliation(s)
- Lucia de Almeida
- 1Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Savita Devi
- 2Department of Academic Pathology, Cedars Sinai Medical Center, Los Angeles, CA, United States
| | - Mohanalaxmi Indramohan
- 2Department of Academic Pathology, Cedars Sinai Medical Center, Los Angeles, CA, United States
| | - Qi-Quan Huang
- 1Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Rojo A. Ratsimandresy
- 2Department of Academic Pathology, Cedars Sinai Medical Center, Los Angeles, CA, United States
| | - Richard M. Pope
- 1Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Andrea Dorfleutner
- 2Department of Academic Pathology, Cedars Sinai Medical Center, Los Angeles, CA, United States,3Department of Biomedical Sciences, Cedars Sinai Medical Center, Los Angeles, CA, United States,4The Kao Autoimmunity Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States,*Correspondence: Andrea Dorfleutner, ; Christian Stehlik,
| | - Christian Stehlik
- 2Department of Academic Pathology, Cedars Sinai Medical Center, Los Angeles, CA, United States,3Department of Biomedical Sciences, Cedars Sinai Medical Center, Los Angeles, CA, United States,4The Kao Autoimmunity Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States,5Samuel Oschin Comprehensive Cancer Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States,*Correspondence: Andrea Dorfleutner, ; Christian Stehlik,
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5
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Isazadeh M, Amandadi M, Haghdoust F, Lotfollazadeh S, Orzáez M, Hosseinkhani S. Split-luciferase complementary assay of NLRP3 PYD-PYD interaction indicates inflammasome formation during inflammation. Anal Biochem 2022; 638:114510. [PMID: 34863712 DOI: 10.1016/j.ab.2021.114510] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/29/2021] [Accepted: 11/30/2021] [Indexed: 01/18/2023]
Abstract
The NLRP3 inflammasome is a key macromolecular complex of the innate immune system that activates the inflammatory signalling cascade in response to a wide range of stimuli. Structural studies have shown that the intracellular cytosolic receptor NLRP3 oligomerizes upon stimulation and serves as a scaffold to form the ASC filaments necessary for procaspase-1 activation. Despite the abundant structural evidences on NLRP3 inflammasome, the interactions of the NLRP3 Pyrin domain and its functional relevance are poorly understood. In this study, the split luciferase complementation assay is used as an alternative approach to investigate NLRP3PYD-NLRP3PYD interactions during inflammasome formation. Since the homotypic NLRP3 interaction is mainly based on electrostatic interactions, a phosphomimetic residue (S5) at the interface of the NLRP3PYDs interactions has been mutated to show a disruptive effect on luciferase activity. According to the results presented, the designed biosensor was able to monitor the NLRP3PYD-NLRP3PYD interaction in vitro. The current reporter assay not only provides a specific NLRP3PYD-NLRP3PYD assay to study the PYD-PYD interaction in vitro, but also provides a suitable system for screening chemicals and drugs to identify activators and inhibitors of NLRP3.
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Affiliation(s)
- Mohsen Isazadeh
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mojdeh Amandadi
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Farnaz Haghdoust
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shima Lotfollazadeh
- Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mar Orzáez
- Laboratory of Peptide and Protein Chemistry, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Saman Hosseinkhani
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
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6
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Ahmed Bhat E, Sajjad N, Ahmad Tantray J, Hor YY, Rather IA. In vitro complex formation of human PYRIN domain-only protein 3 prevented by self-oligomerization of ASC PYD domain. Saudi J Biol Sci 2021; 28:1607-1614. [PMID: 33732046 PMCID: PMC7938106 DOI: 10.1016/j.sjbs.2020.12.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 11/30/2022] Open
Abstract
The formation of inflammasome complexes contributes inactivation of inflammatory caspases viz caspase 1, which is generally considered essential for the innate response. Three proteins constituted this inflammasome complex, such as Nod-like receptors (NLRP or AIM2), ASC possessing caspase-recruiting domain, and caspase-1. The ASC proteins comprise two domains, the N-terminal PYD domain responsible for the interaction of various proteins, including PYD only protein 3 (POP3), and the CARD domain for association with other proteins. The PYRIN Domain-Only Protein POP3 negatively regulates responses to DNA virus infection by preventing the ALR inflammasome formation. POP3 directly interacts with ASC, therefore inhibiting ASC recruitment to AIM2-like receptors (ALRs). In the current study, we designed various constructs of the PYRIN Domain-Only Protein 3 (POP3) and ASC PYD domain to find the best-overexpressed construct for biochemical characterization as well as our complex studies. We cloned, purified, and characterized the PYD domain of pyrin only protein 3 and ASC PYD domain under physiological conditions. Our in vitro study clearly shows that the ASC PYD domain of corresponding amino acid 1-96 aa with ease self-oligomerization in physiological buffer conditions, and complex formation of POP3 PYD (1-83 aa) was inhibited by ASC PYD domain. Besides, we purified the PYD of POP3 protein in low and high salt conditions and different pH values for their biochemical characterization. Our results showed that POP3 formed a dimer under normal physiological conditions and was stable under normal buffer conditions; however, the purification in extremely low pH (pH5.0) conditions shows unstable behavior, the high salt conditions (500 mM NaCl) influence the protein aggregation. SDS PAGE arbitrated the homogeneity of the PYD domain of pyrin only protein 3 and ASC PYD domain of corresponding amino acids 1-83 and 1-96, respectively. Furthermore, our native PAGE shows the PYD domain of pyrin; only protein 3 did not form a complex with ASC PYD domain because of oligomerization mediated by the PYD domain.
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Affiliation(s)
- Eijaz Ahmed Bhat
- Life Science Institute, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Nasreena Sajjad
- Department of Biochemistry, University of Kashmir, Srinagar, 190006, India
| | | | - Yan-Yan Hor
- Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan 38541, South Korea
| | - Irfan A. Rather
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Center of Excellence for Bionanoscience Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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7
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Bracey NA, Platnich JM, Lau A, Chung H, Hyndman ME, MacDonald JA, Chun J, Beck PL, Girardin SE, Gordon PM, Muruve DA. Tissue-selective alternate promoters guide NLRP6 expression. Life Sci Alliance 2020; 4:4/3/e202000897. [PMID: 33376129 PMCID: PMC7772780 DOI: 10.26508/lsa.202000897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/12/2020] [Accepted: 12/15/2020] [Indexed: 12/14/2022] Open
Abstract
The NLRP6 innate immune sensor is regulated by tissue-selective alternate promoters that facilitate translational gene silencing outside of the intestinal epithelium in both humans and mice. The pryin domain (PYD) domain is involved in protein interactions that lead to assembly of immune-sensing complexes such as inflammasomes. The repertoire of PYD-containing genes expressed by a cell type arms tissues with responses against a range of stimuli. The transcriptional regulation of the PYD gene family however is incompletely understood. Alternative promoter utilization was identified as a mechanism regulating the tissue distribution of human PYD gene family members, including NLRP6 that is translationally silenced outside of intestinal tissue. Results show that alternative transcriptional promoters mediate NLRP6 silencing in mice and humans, despite no upstream genomic synteny. Human NLRP6 contains an internal alternative promoter within exon 2 of the PYD, resulting in a truncated mRNA in nonintestinal tissue. In mice, a proximal promoter was used that expanded the 5′ leader sequence restricting nuclear export and abolishing translational efficiency. Nlrp6 was dispensable in disease models targeting the kidney, which expresses noncanonical isoforms. Thus, alternative promoter use is a critical mechanism not just for isoform modulation but for determining expression profile and function of PYD family members.
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Affiliation(s)
- Nathan A Bracey
- Department of Medicine, University of Calgary, Calgary, Canada.,Snyder Institute for Chronic Disease, University of Calgary, Calgary, Canada
| | - Jaye M Platnich
- Department of Medicine, University of Alberta, Edmonton, Canada
| | - Arthur Lau
- Department of Medicine, University of Calgary, Calgary, Canada.,Snyder Institute for Chronic Disease, University of Calgary, Calgary, Canada
| | - Hyunjae Chung
- Department of Medicine, University of Calgary, Calgary, Canada.,Snyder Institute for Chronic Disease, University of Calgary, Calgary, Canada
| | - M Eric Hyndman
- Department of Surgery, University of Calgary, Calgary, Canada
| | - Justin A MacDonald
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Canada
| | - Justin Chun
- Department of Medicine, University of Calgary, Calgary, Canada.,Snyder Institute for Chronic Disease, University of Calgary, Calgary, Canada
| | - Paul L Beck
- Department of Medicine, University of Calgary, Calgary, Canada.,Snyder Institute for Chronic Disease, University of Calgary, Calgary, Canada
| | - Stephen E Girardin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Paul Mk Gordon
- Centre for Health Genomics and Informatics, University of Calgary, Calgary, Canada
| | - Daniel A Muruve
- Department of Medicine, University of Calgary, Calgary, Canada .,Snyder Institute for Chronic Disease, University of Calgary, Calgary, Canada
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8
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Downs KP, Nguyen H, Dorfleutner A, Stehlik C. An overview of the non-canonical inflammasome. Mol Aspects Med 2020; 76:100924. [PMID: 33187725 PMCID: PMC7808250 DOI: 10.1016/j.mam.2020.100924] [Citation(s) in RCA: 145] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/21/2022]
Abstract
Inflammasomes are large cytosolic multiprotein complexes assembled in response to infection and cellular stress, and are crucial for the activation of inflammatory caspases and the subsequent processing and release of pro-inflammatory mediators. While caspase-1 is activated within the canonical inflammasome, the related caspase-4 (also known as caspase-11 in mice) and caspase-5 are activated within the non-canonical inflammasome upon sensing of cytosolic lipopolysaccharide (LPS) from Gram-negative bacteria. However, the consequences of canonical and non-canonical inflammasome activation are similar. Caspase-1 promotes the processing and release of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18 and the release of danger signals, as well as a lytic form of cell death called pyroptosis, whereas caspase-4, caspase-5 and caspase-11 directly promote pyroptosis through cleavage of the pore-forming protein gasdermin D (GSDMD), and trigger a secondary activation of the canonical NLRP3 inflammasome for cytokine release. Since the presence of the non-canonical inflammasome activator LPS leads to endotoxemia and sepsis, non-canonical inflammasome activation and regulation has important clinical ramifications. Here we discuss the mechanism of non-canonical inflammasome activation, mechanisms regulating its activity and its contribution to health and disease.
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Affiliation(s)
- Kevin P Downs
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA, 90048, USA.
| | - Huyen Nguyen
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA, 90048, USA.
| | - Andrea Dorfleutner
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA, 90048, USA; Department of Biomedical Sciences, Cedars Sinai, Los Angeles, CA, 90048, USA.
| | - Christian Stehlik
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA, 90048, USA; Department of Biomedical Sciences, Cedars Sinai, Los Angeles, CA, 90048, USA; Samuel Oschin Comprehensive Cancer Institute, Cedars Sinai, Los Angeles, CA, 90048, USA.
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9
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Devi S, Stehlik C, Dorfleutner A. An Update on CARD Only Proteins (COPs) and PYD Only Proteins (POPs) as Inflammasome Regulators. Int J Mol Sci 2020; 21:E6901. [PMID: 32962268 PMCID: PMC7555848 DOI: 10.3390/ijms21186901] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/17/2020] [Accepted: 09/17/2020] [Indexed: 12/18/2022] Open
Abstract
Inflammasomes are protein scaffolds required for the activation of caspase-1 and the subsequent release of interleukin (IL)-1β, IL-18, and danger signals, as well as the induction of pyroptotic cell death to restore homeostasis following infection and sterile tissue damage. However, excessive inflammasome activation also causes detrimental inflammatory disease. Therefore, extensive control mechanisms are necessary to prevent improper inflammasome responses and inflammatory disease. Inflammasomes are assembled by sequential nucleated polymerization of Pyrin domain (PYD) and caspase recruitment domain (CARD)-containing inflammasome components. Once polymerization is nucleated, this process proceeds in a self-perpetuating manner and represents a point of no return. Therefore, regulation of this key step is crucial for a controlled inflammasome response. Here, we provide an update on two single domain protein families containing either a PYD or a CARD, the PYD-only proteins (POPs) and CARD-only proteins (COPs), respectively. Their structure allows them to occupy and block access to key protein-protein interaction domains necessary for inflammasome assembly, thereby regulating the threshold of these nucleated polymerization events, and consequently, the inflammatory host response.
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Affiliation(s)
- Savita Devi
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA 90048, USA;
| | - Christian Stehlik
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA 90048, USA;
- Department of Biomedical Sciences, and Samuel Oschin Comprehensive Cancer Institute, Cedars Sinai, Los Angeles, CA 90048, USA
| | - Andrea Dorfleutner
- Department of Pathology and Laboratory Medicine, Cedars Sinai, Los Angeles, CA 90048, USA;
- Department of Biomedical Sciences, Cedars Sinai, Los Angeles, CA 90048, USA
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10
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Bosso M, Prelli Bozzo C, Hotter D, Volcic M, Stürzel CM, Rammelt A, Ni Y, Urban S, Becker M, Schelhaas M, Wittmann S, Christensen MH, Schmidt FI, Gramberg T, Sparrer KMJ, Sauter D, Kirchhoff F. Nuclear PYHIN proteins target the host transcription factor Sp1 thereby restricting HIV-1 in human macrophages and CD4+ T cells. PLoS Pathog 2020; 16:e1008752. [PMID: 32760121 PMCID: PMC7433898 DOI: 10.1371/journal.ppat.1008752] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 08/18/2020] [Accepted: 06/26/2020] [Indexed: 02/02/2023] Open
Abstract
Members of the family of pyrin and HIN domain containing (PYHIN) proteins play an emerging role in innate immunity. While absent in melanoma 2 (AIM2) acts a cytosolic sensor of non-self DNA and plays a key role in inflammasome assembly, the γ-interferon-inducible protein 16 (IFI16) restricts retroviral gene expression by sequestering the transcription factor Sp1. Here, we show that the remaining two human PYHIN proteins, i.e. myeloid cell nuclear differentiation antigen (MNDA) and pyrin and HIN domain family member 1 (PYHIN1 or IFIX) share this antiretroviral function of IFI16. On average, knock-down of each of these three nuclear PYHIN proteins increased infectious HIV-1 yield from human macrophages by more than an order of magnitude. Similarly, knock-down of IFI16 strongly increased virus transcription and production in primary CD4+ T cells. The N-terminal pyrin domain (PYD) plus linker region containing a nuclear localization signal (NLS) were generally required and sufficient for Sp1 sequestration and anti-HIV-1 activity of IFI16, MNDA and PYHIN1. Replacement of the linker region of AIM2 by the NLS-containing linker of IFI16 resulted in a predominantly nuclear localization and conferred direct antiviral activity to AIM2 while attenuating its ability to form inflammasomes. The reverse change caused nuclear-to-cytoplasmic relocalization of IFI16 and impaired its antiretroviral activity but did not result in inflammasome assembly. We further show that the Zn-finger domain of Sp1 is critical for the interaction with IFI16 supporting that pyrin domains compete with DNA for Sp1 binding. Finally, we found that human PYHIN proteins also inhibit Hepatitis B virus and simian vacuolating virus 40 as well as the LINE-1 retrotransposon. Altogether, our data show that IFI16, PYHIN1 and MNDA restrict HIV-1 and other viral pathogens by interfering with Sp1-dependent gene expression and support an important role of nuclear PYHIN proteins in innate antiviral immunity.
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Affiliation(s)
- Matteo Bosso
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | | | - Dominik Hotter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Meta Volcic
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | | | - Annika Rammelt
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Yi Ni
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Miriam Becker
- Institute of Cellular Virology, ZMBE, University of Münster, Münster, Germany
| | - Mario Schelhaas
- Institute of Cellular Virology, ZMBE, University of Münster, Münster, Germany
| | - Sabine Wittmann
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | | | | | - Thomas Gramberg
- Institute of Clinical and Molecular Virology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | | | - Daniel Sauter
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
| | - Frank Kirchhoff
- Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany
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11
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Sušjan P, Lainšček D, Strmšek Ž, Hodnik V, Anderluh G, Hafner-Bratkovič I. Selective inhibition of NLRP3 inflammasome by designed peptide originating from ASC. FASEB J 2020; 34:11068-11086. [PMID: 32648626 DOI: 10.1096/fj.201902938rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 06/08/2020] [Accepted: 06/12/2020] [Indexed: 12/13/2022]
Abstract
NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome is a multiprotein complex which forms within cells in response to various microbial and self-derived triggers. Mutations in the gene encoding NLRP3 cause rare cryopyrin-associated periodic syndromes (CAPS) and growing evidence links NLRP3 inflammasome to common diseases such as Alzheimer´s disease. In order to modulate different stages of NLRP3 inflammasome assembly nine peptides whose sequences correspond to segments of inflammasome components NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC) were selected. Five peptides inhibited IL-1β release, caspase-1 activation and ASC oligomerization in response to soluble and particulate NLRP3 triggers. Modulatory peptides also attenuated IL-1β maturation induced by constitutive CAPS-associated NLRP3 mutants. Peptide corresponding to H2-H3 segment of ASC pyrin domain selectively inhibited NLRP3 inflammasome by binding to NLRP3 pyrin domain in the micromolar range. The peptide had no effect on AIM2 and NLRC4 inflammasomes as well as NF-κB pathway. The peptide effectively dampened neutrophil infiltration in the silica-induced peritonitis and when equipped with Antennapedia or Angiopep-2 motifs crossed the blood-brain barrier in a mouse model. Our study demonstrates that peptides represent an important tool for targeting multiprotein inflammatory complexes and can serve as the basis for the development of novel anti-inflammatory strategies for neurodegeneration.
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Affiliation(s)
- Petra Sušjan
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia.,Graduate School of Biomedicine, University of Ljubljana, Ljubljana, Slovenia
| | - Duško Lainšček
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Žiga Strmšek
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia.,Graduate School of Biomedicine, University of Ljubljana, Ljubljana, Slovenia
| | - Vesna Hodnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia.,Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Iva Hafner-Bratkovič
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia.,EN-FIST Centre of Excellence, Ljubljana, Slovenia
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12
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Agrawal I, Jha S. Comprehensive review of ASC structure and function in immune homeostasis and disease. Mol Biol Rep 2020; 47:3077-3096. [PMID: 32124174 DOI: 10.1007/s11033-020-05345-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/22/2020] [Indexed: 12/17/2022]
Abstract
Apoptosis associated speck like protein containing CARD (ASC) is widely researched and recognized as an adaptor protein participating in inflammasome assembly and pyroptosis. It contains a bipartite structure comprising of a pyrin and a caspase recruitment domain (CARD) domain. These two domains help ASC function as an adaptor molecule. ASC is encoded by the gene PYCARD. ASC plays pivotal role in various diseases as well as different homeostatic processes. ASC plays a regulatory role in different cancers showing differential regulation with respect to tissue and stage of disease. Besides cancer, ASC also plays a central role in sensing, regulation, and/or disease progression in bacterial infections, viral infections and in varied inflammatory diseases. ASC is expressed in different types of immune and non-immune cells. Its localization pattern also varies with different kinds of stimuli encountered by cell. This review will summarize the literature on the structure cellular and tissue expression, localization and disease association of ASC.
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Affiliation(s)
- Ishan Agrawal
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur, NH 65, Nagaur Road, Karwad, Jodhpur, Rajasthan, 342037, India
| | - Sushmita Jha
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur, NH 65, Nagaur Road, Karwad, Jodhpur, Rajasthan, 342037, India.
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13
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Zhang X, Liu Z, Li C, Zhang Y, Wang L, Wei J, Qin Q. Characterization of orange-spotted grouper (Epinephelus coioides) ASC and caspase-1 involved in extracellular ATP-mediated immune signaling in fish. FISH & SHELLFISH IMMUNOLOGY 2020; 97:58-71. [PMID: 31837409 DOI: 10.1016/j.fsi.2019.12.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/02/2019] [Accepted: 12/08/2019] [Indexed: 06/10/2023]
Abstract
Apoptosis-associated speck-like protein containing a CARD domain (ASC) is a critical adaptor molecule in multiple inflammasome protein complexes that mediate inflammation and host defense. Caspase-1 is a member of inflammatory caspases that play important roles in the innate immune system. However, few studies have been performed in lower vertebrates such as teleosts and implications of extracellular ATP-mediated immune signalling in fish. Here we identified and characterized novel ASC and caspase-1 genes (namely EcASC and EcCaspase-1) from the orange-spotted grouper (Epinephelus coioides). EcASC and EcCaspase-1 encode 204- and 388-aa proteins which shared 55.34% and 72.89% identity with those in Siniperca chuatsi and Perca flavescens, respectively. EcASC contained a PYRIN domain (aa 5-82) and CARD domain (aa 107-201). EcCaspase1 contained a CARD domain (aa 1-88) and a CASc domain (aa 127-376). Both EcASC and EcCaspase-1 were distributed in all tissues tested in the healthy grouper. The expression of EcASC and EcCaspase-1 was significantly upregulated in response to ATP infection. Subcellular localization analysis showed that EcCaspase-1 exhibited a clear distribution in both cytoplasm and nucleus. In contrast, EcASC was observed in the cytoplasm as speck-like structures, which are called "pyroptosomes". EcCaspase-1 co-localized with the spot-like protein (EcASC). Overexpression of EcASC and EcCaspase-1 inhibited NF-κB activation and promoted P53 activation in grouper spleen (GS) cells. Extracellular ATP was an effective signaling molecule that activates the innate immune response, rapidly upregulating the expression of EcASC and EcCaspase1, and enhancing their promotion of proinflammatory cytokine expression in GS cells. Both EcASC and EcCaspase-1 promoted ATP-induced apoptosis. Our results suggested that the interactions of inflammatory EcCaspase-1 with EcASC proteins were associated with extracellular ATP-mediated immune signaling in fish.
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Affiliation(s)
- Xin Zhang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Zetian Liu
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Chen Li
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Ya Zhang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Liqun Wang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Jingguang Wei
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China.
| | - Qiwei Qin
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266000, China.
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14
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de Alba E. Structure, interactions and self-assembly of ASC-dependent inflammasomes. Arch Biochem Biophys 2019; 670:15-31. [PMID: 31152698 PMCID: PMC8455077 DOI: 10.1016/j.abb.2019.05.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 05/10/2019] [Accepted: 05/28/2019] [Indexed: 12/12/2022]
Abstract
The inflammasome is a multi-protein platform that assembles upon the presence of cues derived from infection or tissue damage, and triggers the inflammatory response. Inflammasome components include sensor proteins that detect danger signals, procaspase 1 and the adapter ASC (apoptosis-associated speck-like protein containing a CARD) tethering these molecules together. Upon inflammasome assembly, procaspase 1 self-activates and renders functional cytokines to arbitrate in the defense mechanism. This assembly is mediated by self-association and protein interactions via Death Domains. The inflammasome plays a critical role in innate immunity and its dysregulation is the culprit of many autoimmune disorders. An in-depth understanding of the factors involved in inflammasome assembly could help fight these conditions. This review describes our current knowledge on the biophysical aspects of inflammasome formation from the perspective of ASC. The specific characteristics of the three-dimensional solution structure and interdomain dynamics of ASC are explained in relation to its function in inflammasome assembly. Additionally, the review elaborates on the identification of ASC interacting surfaces at the amino acid level using NMR techniques. Finally, the macrostructures formed by full-length ASC and its two Death Domains studied with Transmission Electron Microscopy are compared in the context of a directional model for inflammasome assembly.
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Affiliation(s)
- Eva de Alba
- Department of Bioengineering. School of Engineering. University of California, Merced, 5200 North Lake Road, Merced, CA, 95343, USA.
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15
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The Role of Neuronal NLRP1 Inflammasome in Alzheimer's Disease: Bringing Neurons into the Neuroinflammation Game. Mol Neurobiol 2019; 56:7741-7753. [PMID: 31111399 DOI: 10.1007/s12035-019-1638-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/06/2019] [Indexed: 02/06/2023]
Abstract
The innate immune system and inflammatory response in the brain have critical impacts on the pathogenesis of many neurodegenerative diseases including Alzheimer's disease (AD). In the central nervous system (CNS), the innate immune response is primarily mediated by microglia. However, non-glial cells such as neurons could also partake in inflammatory response independently through inflammasome signalling. The NLR family pyrin domain-containing 1 (NLRP1) inflammasome in the CNS is primarily expressed by pyramidal neurons and oligodendrocytes. NLRP1 is activated in response to amyloid-β (Aβ) aggregates, and its activation subsequently cleaves caspase-1 into its active subunits. The activated caspase-1 proteolytically processes interleukin-1β (IL-1β) and interleukin-18 (IL-18) into maturation whilst co-ordinately triggers caspase-6 which is responsible for apoptosis and axonal degeneration. In addition, caspase-1 activation induces pyroptosis, an inflammatory form of programmed cell death. Studies in murine AD models indicate that the Nlrp1 inflammasome is indeed upregulated in AD and neuronal death is observed leading to cognitive decline. However, the mechanism of NLRP1 inflammasome activation in AD is particularly elusive, given its structural and functional complexities. In this review, we examine the implications of the human NLRP1 inflammasome and its signalling pathways in driving neuroinflammation in AD.
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16
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Nambayan RJT, Sandin SI, Quint DA, Satyadi DM, de Alba E. The inflammasome adapter ASC assembles into filaments with integral participation of its two Death Domains, PYD and CARD. J Biol Chem 2019; 294:439-452. [PMID: 30459235 PMCID: PMC6333874 DOI: 10.1074/jbc.ra118.004407] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 11/17/2018] [Indexed: 11/06/2022] Open
Abstract
The inflammasome is a multiprotein complex necessary for the onset of inflammation. The adapter protein ASC assembles inflammasome components by acting as a molecular glue between danger-signal sensors and procaspase-1. The assembly is mediated by ASC self-association and protein interactions via its two Death Domains, PYD and CARD. Truncated versions of ASC have been shown to form filaments, but information on the filaments formed by full-length ASC is needed to construct a meaningful model of inflammasome assembly. To gain insights into this system, we used a combination of transmission EM, NMR, and computational analysis to investigate intact ASC structures. We show that ASC forms ∼6-7-nm-wide filaments that stack laterally to form bundles. The structural characteristics and dimensions of the bundles indicate that both PYD and CARD are integral parts of the filament. A truncated version of ASC with only the CARD domain (ASCCARD) forms different filaments (∼3-4-nm width), providing further evidence that both domains work in concert in filament assembly. Ring-shaped protein particles bound to pre-existing filaments match the size of ASC dimer structures generated by NMR-based protein docking, suggesting that the ASC dimer could be a basic building block for filament formation. Solution NMR binding studies identified the protein surfaces involved in the ASCCARD-ASCCARD interaction. These data provide new insights into the structural underpinnings of the inflammasome and should inform future efforts to interrogate this important biological system.
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Affiliation(s)
| | - Suzanne I Sandin
- From the Department of Bioengineering
- Chemistry and Chemical Biology Graduate Program
| | - David A Quint
- NSF-CREST Center for Cellular and Biomolecular Machines, and
- Department of Physics, University of California, Merced, California 95343
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17
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Banu H, Joseph MC, Nisar MN. In-silico approach to investigate death domains associated with nano-particle-mediated cellular responses. Comput Biol Chem 2018; 75:11-23. [DOI: 10.1016/j.compbiolchem.2018.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 04/01/2018] [Accepted: 04/21/2018] [Indexed: 11/29/2022]
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18
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Dorfleutner A, Stehlik C. A dRAStic RHOAdblock of Pyrin inflammasome activation. Nat Immunol 2017; 17:900-2. [PMID: 27434003 DOI: 10.1038/ni.3511] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Andrea Dorfleutner
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Robert H. Lurie Comprehensive Cancer Center, Interdepartmental Immunobiology Center and Skin Disease Research Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Christian Stehlik
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Robert H. Lurie Comprehensive Cancer Center, Interdepartmental Immunobiology Center and Skin Disease Research Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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19
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Straub D, Wenkel S. Cross-Species Genome-Wide Identification of Evolutionary Conserved MicroProteins. Genome Biol Evol 2017; 9:777-789. [PMID: 28338802 PMCID: PMC5381583 DOI: 10.1093/gbe/evx041] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2017] [Indexed: 12/30/2022] Open
Abstract
MicroProteins are small single-domain proteins that act by engaging their targets into different, sometimes nonproductive protein complexes. In order to identify novel microProteins in any sequenced genome of interest, we have developed miPFinder, a program that identifies and classifies potential microProteins. In the past years, several microProteins have been discovered in plants where they are mainly involved in the regulation of development by fine-tuning transcription factor activities. The miPFinder algorithm identifies all up to date known plant microProteins and extends the microProtein concept beyond transcription factors to other protein families. Here, we reveal potential microProtein candidates in several plant and animal reference genomes. A large number of these microProteins are species-specific while others evolved early and are evolutionary highly conserved. Most known microProtein genes originated from large ancestral genes by gene duplication, mutation and subsequent degradation. Gene ontology analysis shows that putative microProtein ancestors are often located in the nucleus, and involved in DNA binding and formation of protein complexes. Additionally, microProtein candidates act in plant transcriptional regulation, signal transduction and anatomical structure development. MiPFinder is freely available to find microProteins in any genome and will aid in the identification of novel microProteins in plants and animals.
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Affiliation(s)
- Daniel Straub
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark.,Copenhagen Plant Science Centre, University of Copenhagen, Frederiksberg C, Denmark
| | - Stephan Wenkel
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark.,Copenhagen Plant Science Centre, University of Copenhagen, Frederiksberg C, Denmark
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20
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Indramohan M, Stehlik C, Dorfleutner A. COPs and POPs Patrol Inflammasome Activation. J Mol Biol 2017; 430:153-173. [PMID: 29024695 DOI: 10.1016/j.jmb.2017.10.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 09/28/2017] [Accepted: 10/04/2017] [Indexed: 01/07/2023]
Abstract
Sensing and responding to pathogens and tissue damage is a core mechanism of innate immune host defense, and inflammasomes represent a central cytosolic pattern recognition receptor pathway leading to the generation of the pro-inflammatory cytokines interleukin-1β and interleukin-18 and pyroptotic cell death that causes the subsequent release of danger signals to propagate and perpetuate inflammatory responses. While inflammasome activation is essential for host defense, deregulated inflammasome responses and excessive release of inflammatory cytokines and danger signals are linked to an increasing spectrum of inflammatory diseases. In this review, we will discuss recent developments in elucidating the role of PYRIN domain-only proteins (POPs) and the related CARD-only proteins (COPs) in regulating inflammasome responses and their impact on inflammatory disease.
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Affiliation(s)
- Mohanalaxmi Indramohan
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Christian Stehlik
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Interdepartmental Immunobiology Center and Skin Disease Research Center, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Andrea Dorfleutner
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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21
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Baker PJ, De Nardo D, Moghaddas F, Tran LS, Bachem A, Nguyen T, Hayman T, Tye H, Vince JE, Bedoui S, Ferrero RL, Masters SL. Posttranslational Modification as a Critical Determinant of Cytoplasmic Innate Immune Recognition. Physiol Rev 2017; 97:1165-1209. [DOI: 10.1152/physrev.00026.2016] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 12/21/2022] Open
Abstract
Cell surface innate immune receptors can directly detect a variety of extracellular pathogens to which cytoplasmic innate immune sensors are rarely exposed. Instead, within the cytoplasm, the environment is rife with cellular machinery and signaling pathways that are indirectly perturbed by pathogenic microbes to activate intracellular sensors, such as pyrin, NLRP1, NLRP3, or NLRC4. Therefore, subtle changes in key intracellular processes such as phosphorylation, ubiquitination, and other pathways leading to posttranslational protein modification are key determinants of innate immune recognition in the cytoplasm. This concept is critical to establish the “guard hypothesis” whereby otherwise homeostatic pathways that keep innate immune sensors at bay are released in response to alterations in their posttranslational modification status. Originally identified in plants, evidence that a similar guardlike mechanism exists in humans has recently been identified, whereby a mutation that prevents phosphorylation of the innate immune sensor pyrin triggers a dominantly inherited autoinflammatory disease. It is also noteworthy that even when a cytoplasmic innate immune sensor has a direct ligand, such as bacterial peptidoglycan (NOD1 or NOD2), RNA (RIG-I or MDA5), or DNA (cGAS or IFI16), it can still be influenced by posttranslational modification to dramatically alter its response. Therefore, due to their existence in the cytoplasmic milieu, posttranslational modification is a key determinant of intracellular innate immune receptor functionality.
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Affiliation(s)
- Paul J. Baker
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Dominic De Nardo
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Fiona Moghaddas
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Le Son Tran
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Annabell Bachem
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Tan Nguyen
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Thomas Hayman
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Hazel Tye
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - James E. Vince
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Sammy Bedoui
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Richard L. Ferrero
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
| | - Seth L. Masters
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Hudson Institute of Medical Research, Monash University, Centre for Innate Immunity and Infectious Diseases, Clayton, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia; and Departments of Medical Biology and of Microbiology and Immunology, The University of Melbourne, Parkville, Australia
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22
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The PYRIN domain-only protein POP2 inhibits inflammasome priming and activation. Nat Commun 2017; 8:15556. [PMID: 28580931 PMCID: PMC5465353 DOI: 10.1038/ncomms15556] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 04/07/2017] [Indexed: 01/23/2023] Open
Abstract
Inflammasomes are protein platforms linking recognition of microbe, pathogen-associated and damage-associated molecular patterns by cytosolic sensory proteins to caspase-1 activation. Caspase-1 promotes pyroptotic cell death and the maturation and secretion of interleukin (IL)-1β and IL-18, which trigger inflammatory responses to clear infections and initiate wound-healing; however, excessive responses cause inflammatory disease. Inflammasome assembly requires the PYRIN domain (PYD)-containing adaptor ASC, and depends on PYD–PYD interactions. Here we show that the PYD-only protein POP2 inhibits inflammasome assembly by binding to ASC and interfering with the recruitment of ASC to upstream sensors, which prevents caspase-1 activation and cytokine release. POP2 also impairs macrophage priming by inhibiting the activation of non-canonical IκB kinase ɛ and IκBα, and consequently protects from excessive inflammation and acute shock in vivo. Our findings advance our understanding of the complex regulatory mechanisms that maintain a balanced inflammatory response and highlight important differences between individual POP members. Excessive inflammasome activation leads to inflammatory diseases, but how inflammasomes are regulated by PYD-only adaptors is unclear. Here the authors show that the PYD-only protein POP2 inhibits both inflammasome priming and assembly by interfering, respectively, with IκBα activation and NLRP3-ASC interaction.
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Maharana J, Vats A, Gautam S, Nayak BP, Kumar S, Sendha J, De S. POP1 might be recruiting its type-Ia interface for NLRP3-mediated PYD-PYD interaction: Insights from MD simulation. J Mol Recognit 2017; 30. [PMID: 28370480 DOI: 10.1002/jmr.2632] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 02/14/2017] [Accepted: 02/23/2017] [Indexed: 11/12/2022]
Abstract
Inflammasomes are multiprotein caspase-activating complexes that enhance the maturation and release of proinflammatory cytokines (IL-1β and IL-18) in response to the invading pathogen and/or host-derived cellular stress. These are assembled by the sensory proteins (viz NLRC4, NLRP1, NLRP3, and AIM-2), adaptor protein (ASC), and effector molecule procaspase-1. In NLRP3-mediated inflammasome activation, ASC acts as a mediator between NLRP3 and procaspase-1 for the transmission of signals. A series of homotypic protein-protein interactions (NLRP3PYD :ASCPYD and ASCCARD :CASP1CARD ) propagates the downstream signaling for the production of proinflammatory cytokines. Pyrin-only protein 1 (POP1) is known to act as the regulator of inflammasome. It modulates the ASC-mediated inflammasome assembly by interacting with pyrin domain (PYD) of ASC. However, despite similar electrostatic surface potential, the interaction of POP1 with NLRP3PYD is obscured till date. Herein, to explore the possible PYD-PYD interactions between NLRP3PYD and POP1, a combined approach of protein-protein docking and molecular dynamics simulation was adapted. The current study revealed that POP1's type-Ia interface and type-Ib interface of NLRP3PYD might be crucial for 1:1 PYD-PYD interaction. In addition to type-I mode of interaction, we also observed type-II and type-III interaction modes in two different dynamically stable heterotrimeric complexes (POP1-NLRP3-NLRP3 and POP1-NLRP3-POP1). The inter-residual/atomic distance calculation exposed several critical residues that possibly govern the said interaction, which need further investigation. Overall, the findings of this study will shed new light on hitherto concealed molecular mechanisms underlying NLRP3-mediated inflammasome, which will have strong future therapeutic implications.
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Affiliation(s)
- Jitendra Maharana
- Department of Bioinformatics, Orissa University of Agriculture and Technology, Bhubaneswar, -751003, Odisha, India
| | - Ashutosh Vats
- Animal Genomics Lab, Animal Biotechnology Centre, ICAR-National Dairy Research Institute, Karnal, 751003, Haryana, India
| | - Santwana Gautam
- Department of Bioinformatics, Orissa University of Agriculture and Technology, Bhubaneswar, -751003, Odisha, India
| | - Bibhu Prasad Nayak
- Department of Bioinformatics, Orissa University of Agriculture and Technology, Bhubaneswar, -751003, Odisha, India
| | - Sushil Kumar
- Animal Genomics Lab, Animal Biotechnology Centre, ICAR-National Dairy Research Institute, Karnal, 751003, Haryana, India
| | - Jasobanta Sendha
- Department of Bioinformatics, Orissa University of Agriculture and Technology, Bhubaneswar, -751003, Odisha, India
| | - Sachinandan De
- Animal Genomics Lab, Animal Biotechnology Centre, ICAR-National Dairy Research Institute, Karnal, 751003, Haryana, India
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24
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Oroz J, Barrera-Vilarmau S, Alfonso C, Rivas G, de Alba E. ASC Pyrin Domain Self-associates and Binds NLRP3 Protein Using Equivalent Binding Interfaces. J Biol Chem 2016; 291:19487-501. [PMID: 27432880 PMCID: PMC5016686 DOI: 10.1074/jbc.m116.741082] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/08/2016] [Indexed: 11/06/2022] Open
Abstract
Death domain superfamily members typically act as adaptors mediating in the assembly of supramolecular complexes with critical apoptosis and inflammation functions. These modular proteins consist of death domains, death effector domains, caspase recruitment domains, and pyrin domains (PYD). Despite the high structural similarity among them, only homotypic interactions participate in complex formation, suggesting that subtle factors differentiate each interaction type. It is thus critical to identify these factors as an essential step toward the understanding of the molecular basis of apoptosis and inflammation. The proteins apoptosis-associated speck-like protein containing a CARD (ASC) and NLRP3 play key roles in the regulation of apoptosis and inflammation through self-association and protein-protein interactions mediated by their PYDs. To better understand the molecular basis of their function, we have characterized ASC and NLRP3 PYD self-association and their intermolecular interaction by solution NMR spectroscopy and analytical ultracentrifugation. We found that ASC self-associates and binds NLRP3 PYD through equivalent protein regions, with higher binding affinity for the latter. These regions are located at opposite sides of the protein allowing multimeric complex formation previously shown in ASC PYD fibril assemblies. We show that NLRP3 PYD coexists in solution as a monomer and highly populated large-order oligomerized species. Despite this, we determined its monomeric three-dimensional solution structure by NMR and characterized its binding to ASC PYD. Using our novel structural data, we propose molecular models of ASC·ASC and ASC·NLRP3 PYD early supramolecular complexes, providing new insights into the molecular mechanisms of inflammasome and apoptosis signaling.
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Affiliation(s)
- Javier Oroz
- From the Centro de Investigaciones Biológicas, Departments of Chemical and Physical Biology and the German Center for Neurodegenerative Diseases (DZNE), ℅Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen-37077, Germany, and
| | - Susana Barrera-Vilarmau
- From the Centro de Investigaciones Biológicas, Departments of Chemical and Physical Biology and
| | | | | | - Eva de Alba
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, 9 Madrid-28040, Spain, the Health Sciences Research Institute, University of California at Merced, Merced, California 95343
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25
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Abstract
Inflammasomes are protein complexes that promote the maturation and release of pro-inflammatory cytokines and danger signals as well as pyroptosis in response to infections and cellular stress. Inflammasomes consist of a sensor, an adapter, and the effector caspase-1, which interact through homotypic interactions of caspase recruitment domains (CARDs) or PYRIN domains (PYDs). Hence, decoy proteins encoding only a CARD or PYD, COPs and POPs, respectively, are assumed to inhibit inflammasome assembly. Sensors encoding a PYD belong to the families of NOD-like receptors containing a PYD (NLRPs) or AIM2-like receptors (ALRs), which interact with the PYD- and CARD-containing adapter ASC through homotypic PYD interactions. Subsequently, ASC undergoes PYD-dependent oligomerization, which promotes CARD-mediated interactions between ASC and caspase-1, resulting in caspase-1 activation. POPs are suggested to interfere with the interaction between NLRPs/ALRs and ASC to prevent nucleation of ASC and therefore prevent an oligomeric platform for caspase-1 activation. Similarly, COPs are suggested to bind to the CARD of caspase-1 to prevent its recruitment to the oligomeric ASC platform and its activation. Alternatively, the adapter ASC may regulate inflammasome activity by expressing different isoforms, which are either capable or incapable of assembling an oligomeric ASC platform. The molecular mechanism of inflammasome assembly has only recently been elucidated, but the effects of most COPs and POPs on inflammasome assembly have not been investigated. Here, we discuss our model of COP- and POP-mediated inflammasome regulation.
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Affiliation(s)
- Andrea Dorfleutner
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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26
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de Almeida L, Khare S, Misharin AV, Patel R, Ratsimandresy RA, Wallin MC, Perlman H, Greaves DR, Hoffman HM, Dorfleutner A, Stehlik C. The PYRIN Domain-only Protein POP1 Inhibits Inflammasome Assembly and Ameliorates Inflammatory Disease. Immunity 2015; 43:264-76. [PMID: 26275995 DOI: 10.1016/j.immuni.2015.07.018] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 05/08/2015] [Accepted: 05/27/2015] [Indexed: 01/21/2023]
Abstract
In response to infections and tissue damage, ASC-containing inflammasome protein complexes are assembled that promote caspase-1 activation, IL-1β and IL-18 processing and release, pyroptosis, and the release of ASC particles. However, excessive or persistent activation of the inflammasome causes inflammatory diseases. Therefore, a well-balanced inflammasome response is crucial for the maintenance of homeostasis. We show that the PYD-only protein POP1 inhibited ASC-dependent inflammasome assembly by preventing inflammasome nucleation, and consequently interfered with caspase-1 activation, IL-1β and IL-18 release, pyroptosis, and the release of ASC particles. There is no mouse ortholog for POP1, but transgenic expression of human POP1 in monocytes, macrophages, and dendritic cells protected mice from systemic inflammation triggered by molecular PAMPs, inflammasome component NLRP3 mutation, and ASC danger particles. POP1 expression was regulated by TLR and IL-1R signaling, and we propose that POP1 provides a regulatory feedback loop that shuts down excessive inflammatory responses and thereby prevents systemic inflammation.
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Affiliation(s)
- Lucia de Almeida
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sonal Khare
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Alexander V Misharin
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Rajul Patel
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Rojo A Ratsimandresy
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Melissa C Wallin
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Harris Perlman
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - David R Greaves
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Hal M Hoffman
- Division of Rheumatology, Allergy, and Immunology, Department of Pediatrics, School of Medicine, University of California at San Diego (UCSD) and San Diego Branch, Ludwig Institute of Cancer Research, La Jolla, CA 92093, USA
| | - Andrea Dorfleutner
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Christian Stehlik
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Interdepartmental Immunobiology Center and Skin Disease Research Center, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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27
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Radian AD, Khare S, Chu LH, Dorfleutner A, Stehlik C. ATP binding by NLRP7 is required for inflammasome activation in response to bacterial lipopeptides. Mol Immunol 2015; 67:294-302. [PMID: 26143398 DOI: 10.1016/j.molimm.2015.06.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/11/2015] [Accepted: 06/15/2015] [Indexed: 02/07/2023]
Abstract
Nucleotide-binding oligimerization domain (NOD)-like receptors (NLRs) are pattern recognition receptors (PRRs) involved in innate immune responses. NLRs encode a central nucleotide-binding domain (NBD) consisting of the NAIP, CIITA, HET-E and TP1 (NACHT) domain and the NACHT associated domain (NAD), which facilitates receptor oligomerization and downstream inflammasome signaling. The NBD contains highly conserved regions, known as Walker motifs, that are required for nucleotide binding and hydrolysis. The NLR containing a PYRIN domain (PYD) 7 (NLRP7) has been recently shown to assemble an ASC and caspase-1-containing high molecular weight inflammasome complex in response to microbial acylated lipopeptides and Staphylococcus aureus infection. However, the molecular mechanism responsible for NLRP7 inflammasome activation is still elusive. Here we demonstrate that the NBD of NLRP7 is an ATP binding domain and has ATPase activity. We further show that an intact nucleotide-binding Walker A motif is required for NBD-mediated nucleotide binding and hydrolysis, oligomerization, and NLRP7 inflammasome formation and activity. Accordingly, THP-1 cells expressing a mutated Walker A motif display defective NLRP7 inflammasome activation, interleukin (IL)-1β release and pyroptosis in response to acylated lipopeptides and S. aureus infection. Taken together, our results provide novel insights into the mechanism of NLRP7 inflammasome assembly.
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Affiliation(s)
- Alexander D Radian
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Driskill Graduate Program in Life Sciences (DGP), Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sonal Khare
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Lan H Chu
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Driskill Graduate Program in Life Sciences (DGP), Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Andrea Dorfleutner
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| | - Christian Stehlik
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Interdepartmental Immunobiology Center and Skin Disease Research Center, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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