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Lyu Z, Yang X, Yahashiri A, Ha S, McCausland JW, Chen X, Britton BM, Weiss DS, Xiao J. E. coli FtsN coordinates synthesis and degradation of septal peptidoglycan by partitioning between a synthesis track and a denuded glycan track. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.13.594014. [PMID: 39253420 PMCID: PMC11383011 DOI: 10.1101/2024.05.13.594014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/11/2024]
Abstract
The E. coli cell division protein FtsN was proposed to coordinate septal peptidoglycan (sPG) synthesis and degradation to ensure robust cell wall constriction without lethal lesions. Although the precise mechanism remains unclear, previous work highlights the importance of two FtsN domains: the E domain, which interacts with and activates the sPG synthesis complex FtsWIQLB, and the SPOR domain, which binds to denuded glycan (dnG) strands, key intermediates in sPG degradation. Here, we used single-molecule tracking of FtsN and FtsW (a proxy for the sPG synthesis complex FtsWIQLB) to investigate how FtsN coordinates the two opposing processes. We observed dynamic behaviors indicating that FtsN's SPOR domain binds to dnGs cooperatively, which both sequesters the sPG synthesis complex on dnG (termed as the dnG-track) and protects dnGs from degradation by lytic transglycosylases (LTs). The release of the SPOR domain from dnGs leads to activating the sPG synthesis complex on the sPG-track and simultaneously exposing those same dnGs to degradation. Furthermore, FtsN's SPOR domain self-interacts and facilitates the formation of a multimeric sPG synthesis complex on both tracks. The cooperative self-interaction of the SPOR domain creates a sensitive switch to regulate the partitioning of FtsN between the dnG- and sPG-tracks, thereby controlling the balance between sequestered and active populations of the sPG synthesis complex. As such, FtsN coordinates sPG synthesis and degradation in space and time.
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2
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Tian X, Ai J, Tian X, Wei X. cGAS-STING pathway agonists are promising vaccine adjuvants. Med Res Rev 2024; 44:1768-1799. [PMID: 38323921 DOI: 10.1002/med.22016] [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: 10/17/2023] [Revised: 12/10/2023] [Accepted: 01/09/2024] [Indexed: 02/08/2024]
Abstract
Adjuvants are of critical value in vaccine development as they act on enhancing immunogenicity of antigen and inducing long-lasting immunity. However, there are only a few adjuvants that have been approved for clinical use, which highlights the need for exploring and developing new adjuvants to meet the growing demand for vaccination. Recently, emerging evidence demonstrates that the cGAS-STING pathway orchestrates innate and adaptive immunity by generating type I interferon responses. Many cGAS-STING pathway agonists have been developed and tested in preclinical research for the treatment of cancer or infectious diseases with promising results. As adjuvants, cGAS-STING agonists have demonstrated their potential to activate robust defense immunity in various diseases, including COVID-19 infection. This review summarized the current developments in the field of cGAS-STING agonists with a special focus on the latest applications of cGAS-STING agonists as adjuvants in vaccination. Potential challenges were also discussed in the hope of sparking future research interests to further the development of cGAS-STING as vaccine adjuvants.
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Affiliation(s)
- Xinyu Tian
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Centre for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
| | - Jiayuan Ai
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Centre for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
| | - Xiaohe Tian
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Centre for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
| | - Xiawei Wei
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Centre for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
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3
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Bonhomme D, Poirier EZ. Early signaling pathways in virus-infected cells. Curr Opin Virol 2024; 66:101411. [PMID: 38718574 DOI: 10.1016/j.coviro.2024.101411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/05/2024] [Accepted: 04/10/2024] [Indexed: 06/07/2024]
Abstract
Virus infection activates specific pattern recognition receptors and immune signal transduction, resulting in pro-inflammatory cytokine production and activation of innate immunity. We describe here the molecular organization of early signaling pathways downstream of viral recognition, including conformational changes, post-translational modifications, formation of oligomers, and generation of small-molecule second messengers. Such molecular organization allows tight regulation of immune signal transduction, characterized by swift but transient responses, nonlinearity, and signal amplification. Pathologies of early immune signaling caused by genomic mutations illustrate the fine regulation of the immune transduction cascade.
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Affiliation(s)
- Delphine Bonhomme
- Institut Curie, Stem Cell Immunity Lab, PSL Research University, INSERM U932, Paris, France
| | - Enzo Z Poirier
- Institut Curie, Stem Cell Immunity Lab, PSL Research University, INSERM U932, Paris, France.
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4
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Wu S, Gabelli SB, Sohn J. The structural basis for 2'-5'/3'-5'-cGAMP synthesis by cGAS. Nat Commun 2024; 15:4012. [PMID: 38740774 PMCID: PMC11091121 DOI: 10.1038/s41467-024-48365-3] [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: 05/31/2023] [Accepted: 04/26/2024] [Indexed: 05/16/2024] Open
Abstract
cGAS activates innate immune responses against cytosolic double-stranded DNA. Here, by determining crystal structures of cGAS at various reaction stages, we report a unifying catalytic mechanism. apo-cGAS assumes an array of inactive conformations and binds NTPs nonproductively. Dimerization-coupled double-stranded DNA-binding then affixes the active site into a rigid lock for productive metal•substrate binding. A web-like network of protein•NTP, intra-NTP, and inter-NTP interactions ensures the stepwise synthesis of 2'-5'/3'-5'-linked cGAMP while discriminating against noncognate NTPs and off-pathway intermediates. One divalent metal is sufficient for productive substrate binding, and capturing the second divalent metal is tightly coupled to nucleotide and linkage specificities, a process which manganese is preferred over magnesium by 100-fold. Additionally, we elucidate how mouse cGAS achieves more stringent NTP and linkage specificities than human cGAS. Together, our results reveal that an adaptable, yet precise lock-and-key-like mechanism underpins cGAS catalysis.
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Affiliation(s)
- Shuai Wu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sandra B Gabelli
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Discovery Chemistry, Merck Laboratories, West Point, PA, USA
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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5
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Schmid M, Fischer P, Engl M, Widder J, Kerschbaum-Gruber S, Slade D. The interplay between autophagy and cGAS-STING signaling and its implications for cancer. Front Immunol 2024; 15:1356369. [PMID: 38660307 PMCID: PMC11039819 DOI: 10.3389/fimmu.2024.1356369] [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: 12/15/2023] [Accepted: 03/26/2024] [Indexed: 04/26/2024] Open
Abstract
Autophagy is an intracellular process that targets various cargos for degradation, including members of the cGAS-STING signaling cascade. cGAS-STING senses cytosolic double-stranded DNA and triggers an innate immune response through type I interferons. Emerging evidence suggests that autophagy plays a crucial role in regulating and fine-tuning cGAS-STING signaling. Reciprocally, cGAS-STING pathway members can actively induce canonical as well as various non-canonical forms of autophagy, establishing a regulatory network of feedback mechanisms that alter both the cGAS-STING and the autophagic pathway. The crosstalk between autophagy and the cGAS-STING pathway impacts a wide variety of cellular processes such as protection against pathogenic infections as well as signaling in neurodegenerative disease, autoinflammatory disease and cancer. Here we provide a comprehensive overview of the mechanisms involved in autophagy and cGAS-STING signaling, with a specific focus on the interactions between the two pathways and their importance for cancer.
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Affiliation(s)
- Maximilian Schmid
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
| | - Patrick Fischer
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
| | - Magdalena Engl
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
- Vienna Biocenter PhD Program, a Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Joachim Widder
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Sylvia Kerschbaum-Gruber
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Dea Slade
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
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6
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Li Q, Wu P, Du Q, Hanif U, Hu H, Li K. cGAS-STING, an important signaling pathway in diseases and their therapy. MedComm (Beijing) 2024; 5:e511. [PMID: 38525112 PMCID: PMC10960729 DOI: 10.1002/mco2.511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 02/15/2024] [Accepted: 02/21/2024] [Indexed: 03/26/2024] Open
Abstract
Since cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway was discovered in 2013, great progress has been made to elucidate the origin, function, and regulating mechanism of cGAS-STING signaling pathway in the past decade. Meanwhile, the triggering and transduction mechanisms have been continuously illuminated. cGAS-STING plays a key role in human diseases, particularly DNA-triggered inflammatory diseases, making it a potentially effective therapeutic target for inflammation-related diseases. Here, we aim to summarize the ancient origin of the cGAS-STING defense mechanism, as well as the triggers, transduction, and regulating mechanisms of the cGAS-STING. We will also focus on the important roles of cGAS-STING signal under pathological conditions, such as infections, cancers, autoimmune diseases, neurological diseases, and visceral inflammations, and review the progress in drug development targeting cGAS-STING signaling pathway. The main directions and potential obstacles in the regulating mechanism research and therapeutic drug development of the cGAS-STING signaling pathway for inflammatory diseases and cancers will be discussed. These research advancements expand our understanding of cGAS-STING, provide a theoretical basis for further exploration of the roles of cGAS-STING in diseases, and open up new strategies for targeting cGAS-STING as a promising therapeutic intervention in multiple diseases.
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Affiliation(s)
- Qijie Li
- Sichuan province Medical and Engineering Interdisciplinary Research Center of Nursing & Materials/Nursing Key Laboratory of Sichuan ProvinceWest China Hospital, Sichuan University/West China School of NursingSichuan UniversityChengduSichuanChina
| | - Ping Wu
- Department of Occupational DiseasesThe Second Affiliated Hospital of Chengdu Medical College (China National Nuclear Corporation 416 Hospital)ChengduSichuanChina
| | - Qiujing Du
- Sichuan province Medical and Engineering Interdisciplinary Research Center of Nursing & Materials/Nursing Key Laboratory of Sichuan ProvinceWest China Hospital, Sichuan University/West China School of NursingSichuan UniversityChengduSichuanChina
| | - Ullah Hanif
- Sichuan province Medical and Engineering Interdisciplinary Research Center of Nursing & Materials/Nursing Key Laboratory of Sichuan ProvinceWest China Hospital, Sichuan University/West China School of NursingSichuan UniversityChengduSichuanChina
| | - Hongbo Hu
- Center for Immunology and HematologyState Key Laboratory of BiotherapyWest China Hospital, Sichuan UniversityChengduSichuanChina
| | - Ka Li
- Sichuan province Medical and Engineering Interdisciplinary Research Center of Nursing & Materials/Nursing Key Laboratory of Sichuan ProvinceWest China Hospital, Sichuan University/West China School of NursingSichuan UniversityChengduSichuanChina
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7
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Abhishek S, Deeksha W, Nethravathi KR, Davari MD, Rajakumara E. Allosteric crosstalk in modular proteins: Function fine-tuning and drug design. Comput Struct Biotechnol J 2023; 21:5003-5015. [PMID: 37867971 PMCID: PMC10589753 DOI: 10.1016/j.csbj.2023.10.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 10/07/2023] [Accepted: 10/08/2023] [Indexed: 10/24/2023] Open
Abstract
Modular proteins are regulatory proteins that carry out more than one function. These proteins upregulate or downregulate a biochemical cascade to establish homeostasis in cells. To switch the function or alter the efficiency (based on cellular needs), these proteins require different facilitators that bind to a site different from the catalytic (active/orthosteric) site, aka 'allosteric site', and fine-tune their function. These facilitators (or effectors) are allosteric modulators. In this Review, we have discussed the allostery, characterized them based on their mechanisms, and discussed how allostery plays an important role in the activity modulation and function fine-tuning of proteins. Recently there is an emergence in the discovery of allosteric drugs. We have also emphasized the role, significance, and future of allostery in therapeutic applications.
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Affiliation(s)
- Suman Abhishek
- Macromolecular Structural Biology lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502284, India
| | - Waghela Deeksha
- Macromolecular Structural Biology lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502284, India
| | | | - Mehdi D. Davari
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle 06120, Germany
| | - Eerappa Rajakumara
- Macromolecular Structural Biology lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502284, India
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8
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Kumar V, Bauer C, Stewart JH. Cancer cell-specific cGAS/STING Signaling pathway in the era of advancing cancer cell biology. Eur J Cell Biol 2023; 102:151338. [PMID: 37423035 DOI: 10.1016/j.ejcb.2023.151338] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/27/2023] [Accepted: 07/04/2023] [Indexed: 07/11/2023] Open
Abstract
Pattern-recognition receptors (PRRs) are critical to recognizing endogenous and exogenous threats to mount a protective proinflammatory innate immune response. PRRs may be located on the outer cell membrane, cytosol, and nucleus. The cGAS/STING signaling pathway is a cytosolic PRR system. Notably, cGAS is also present in the nucleus. The cGAS-mediated recognition of cytosolic dsDNA and its cleavage into cGAMP activates STING. Furthermore, STING activation through its downstream signaling triggers different interferon-stimulating genes (ISGs), initiating the release of type 1 interferons (IFNs) and NF-κB-mediated release of proinflammatory cytokines and molecules. Activating cGAS/STING generates type 1 IFN, which may prevent cellular transformation and cancer development, growth, and metastasis. The current article delineates the impact of the cancer cell-specific cGAS/STING signaling pathway alteration in tumors and its impact on tumor growth and metastasis. This article further discusses different approaches to specifically target cGAS/STING signaling in cancer cells to inhibit tumor growth and metastasis in conjunction with existing anticancer therapies.
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Affiliation(s)
- Vijay Kumar
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA 70012, USA.
| | - Caitlin Bauer
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA 70012, USA
| | - John H Stewart
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA 70012, USA; Louisiana Children's Medical Center Cancer Center, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA 70012, USA.
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9
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Lewicky JD, Martel AL, Gupta MR, Roy R, Rodriguez GM, Vanderhyden BC, Le HT. Conventional DNA-Damaging Cancer Therapies and Emerging cGAS-STING Activation: A Review and Perspectives Regarding Immunotherapeutic Potential. Cancers (Basel) 2023; 15:4127. [PMID: 37627155 PMCID: PMC10453198 DOI: 10.3390/cancers15164127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/10/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
Many traditional cancer treatments such as radiation and chemotherapy are known to induce cellular DNA damage as part of their cytotoxic activity. The cGAS-STING signaling axis, a key member of the DNA damage response that acts as a sensor of foreign or aberrant cytosolic DNA, is helping to rationalize the DNA-damaging activity of these treatments and their emerging immunostimulatory capacity. Moreover, cGAS-STING, which is attracting considerable attention for its ability to promote antitumor immune responses, may fundamentally be able to address many of the barriers limiting the success of cancer immunotherapy strategies, including the immunosuppressive tumor microenvironment. Herein, we review the traditional cancer therapies that have been linked with cGAS-STING activation, highlighting their targets with respect to their role and function in the DNA damage response. As part of the review, an emerging "chemoimmunotherapy" concept whereby DNA-damaging agents are used for the indirect activation of STING is discussed as an alternative to the direct molecular agonism strategies that are in development, but have yet to achieve clinical approval. The potential of this approach to address some of the inherent and emerging limitations of cGAS-STING signaling in cancer immunotherapy is also discussed. Ultimately, it is becoming clear that in order to successfully employ the immunotherapeutic potential of the cGAS-STING axis, a balance between its contrasting antitumor and protumor/inflammatory activities will need to be achieved.
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Affiliation(s)
- Jordan D. Lewicky
- Health Sciences North Research Institute, 56 Walford Road, Sudbury, ON P3E 2H2, Canada; (J.D.L.); (A.L.M.)
| | - Alexandrine L. Martel
- Health Sciences North Research Institute, 56 Walford Road, Sudbury, ON P3E 2H2, Canada; (J.D.L.); (A.L.M.)
| | - Mukul Raj Gupta
- Glycosciences and Nanomaterial Laboratory, Université du Québec à Montréal, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada; (M.R.G.); (R.R.)
| | - René Roy
- Glycosciences and Nanomaterial Laboratory, Université du Québec à Montréal, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada; (M.R.G.); (R.R.)
| | - Galaxia M. Rodriguez
- Cancer Therapeutics Program, Ottawa Hospital Research Institute, 501 Smyth Rd., Ottawa, ON K1H 8L6, Canada; (G.M.R.); (B.C.V.)
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON K1H 8M5, Canada
| | - Barbara C. Vanderhyden
- Cancer Therapeutics Program, Ottawa Hospital Research Institute, 501 Smyth Rd., Ottawa, ON K1H 8L6, Canada; (G.M.R.); (B.C.V.)
- Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Rd., Ottawa, ON K1H 8M5, Canada
| | - Hoang-Thanh Le
- Health Sciences North Research Institute, 56 Walford Road, Sudbury, ON P3E 2H2, Canada; (J.D.L.); (A.L.M.)
- Medicinal Sciences Division, NOSM University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
- School of Natural Sciences, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
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10
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Chauvin SD, Stinson WA, Platt DJ, Poddar S, Miner JJ. Regulation of cGAS and STING signaling during inflammation and infection. J Biol Chem 2023; 299:104866. [PMID: 37247757 PMCID: PMC10316007 DOI: 10.1016/j.jbc.2023.104866] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 05/31/2023] Open
Abstract
Stimulator of interferon genes (STING) is a sensor of cyclic dinucleotides including cyclic GMP-AMP, which is produced by cyclic GMP-AMP synthase (cGAS) in response to cytosolic DNA. The cGAS-STING signaling pathway regulates both innate and adaptive immune responses, as well as fundamental cellular functions such as autophagy, senescence, and apoptosis. Mutations leading to constitutive activation of STING cause devastating human diseases. Thus, the cGAS-STING pathway is of great interest because of its role in diverse cellular processes and because of the potential therapeutic implications of targeting cGAS and STING. Here, we review molecular and cellular mechanisms of STING signaling, and we propose a framework for understanding the immunological and other cellular functions of STING in the context of disease.
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Affiliation(s)
- Samuel D Chauvin
- Departments of Medicine and Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - W Alexander Stinson
- Departments of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Derek J Platt
- Department Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Subhajit Poddar
- Departments of Medicine and Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Jonathan J Miner
- Departments of Medicine and Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Departments of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA; Department Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA; Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA.
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11
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Chen G, Obal D. Detecting and measuring of GPCR signaling - comparison of human induced pluripotent stem cells and immortal cell lines. Front Endocrinol (Lausanne) 2023; 14:1179600. [PMID: 37293485 PMCID: PMC10244570 DOI: 10.3389/fendo.2023.1179600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 04/12/2023] [Indexed: 06/10/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are a large family of transmembrane proteins that play a major role in many physiological processes, and thus GPCR-targeted drug development has been widely promoted. Although research findings generated in immortal cell lines have contributed to the advancement of the GPCR field, the homogenous genetic backgrounds, and the overexpression of GPCRs in these cell lines make it difficult to correlate the results with clinical patients. Human induced pluripotent stem cells (hiPSCs) have the potential to overcome these limitations, because they contain patient specific genetic information and can differentiate into numerous cell types. To detect GPCRs in hiPSCs, highly selective labeling and sensitive imaging techniques are required. This review summarizes existing resonance energy transfer and protein complementation assay technologies, as well as existing and new labeling methods. The difficulties of extending existing detection methods to hiPSCs are discussed, as well as the potential of hiPSCs to expand GPCR research towards personalized medicine.
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Affiliation(s)
- Gaoxian Chen
- Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, Stanford, CA, United States
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, United States
| | - Detlef Obal
- Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, Stanford, CA, United States
- Stanford Cardiovascular Institute, Stanford University, Stanford, CA, United States
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12
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Song J, Yang RR, Chang J, Liu YD, Lu CH, Chen LF, Guo H, Zhang YH, Fan ZS, Zhou JY, Zhou GZ, Zhang KK, Luo XM, Chen KX, Jiang HL, Zhang SL, Zheng MY. Discovery and characterization of a novel cGAS covalent inhibitor for the treatment of inflammatory bowel disease. Acta Pharmacol Sin 2023; 44:791-800. [PMID: 36229599 PMCID: PMC10043009 DOI: 10.1038/s41401-022-01002-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 09/19/2022] [Indexed: 11/09/2022] Open
Abstract
Cyclic GMP-AMP synthase (cGAS), a cytosolic DNA sensor, acts as a nucleotidyl transferase that catalyzes ATP and GTP to form cyclic GMP-AMP (cGAMP) and plays a critical role in innate immunity. Hyperactivation of cGAS-STING signaling contributes to hyperinflammatory responses. Therefore, cGAS is considered a promising target for the treatment of inflammatory diseases. Herein, we report the discovery and identification of several novel types of cGAS inhibitors by pyrophosphatase (PPiase)-coupled activity assays. Among these inhibitors, 1-(1-phenyl-3,4-dihydro-1H-pyrrolo[1,2-a]pyrazin-2-yl)prop-2-yn-1-one (compound 3) displayed the highest potency and selectivity at the cellular level. Compound 3 exhibited better inhibitory activity and pathway selectivity than RU.521, which is a selective cGAS inhibitor with anti-inflammatory effects in vitro and in vivo. Thermostability analysis, nuclear magnetic resonance and isothermal titration calorimetry assays confirmed that compound 3 directly binds to the cGAS protein. Mass spectrometry and mutation analysis revealed that compound 3 covalently binds to Cys419 of cGAS. Notably, compound 3 demonstrated promising therapeutic efficacy in a dextran sulfate sodium (DSS)-induced mouse colitis model. These results collectively suggest that compound 3 will be useful for understanding the biological function of cGAS and has the potential to be further developed for inflammatory disease therapies.
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Affiliation(s)
- Jia Song
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, China
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Rui-Rui Yang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Shanghai Institute for Advanced Immunochemical Studies, and School of Life Science and Technology, Shanghai Tech University, Shanghai, 200031, China
| | - Jie Chang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Ya-Dan Liu
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Cheng-Hao Lu
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Li-Fan Chen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hao Guo
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying-Hui Zhang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zi-Sheng Fan
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Jing-Yi Zhou
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Gui-Zhen Zhou
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Ke-Ke Zhang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Xiao-Min Luo
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Kai-Xian Chen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Hua-Liang Jiang
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, China.
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Shanghai Institute for Advanced Immunochemical Studies, and School of Life Science and Technology, Shanghai Tech University, Shanghai, 200031, China.
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
| | - Su-Lin Zhang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Ming-Yue Zheng
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
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13
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Song JX, Villagomes D, Zhao H, Zhu M. cGAS in nucleus: The link between immune response and DNA damage repair. Front Immunol 2022; 13:1076784. [PMID: 36591232 PMCID: PMC9797516 DOI: 10.3389/fimmu.2022.1076784] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022] Open
Abstract
As the first barrier of host defense, innate immunity sets up the parclose to keep out external microbial or virus attacks. Depending on the type of pathogens, several cytoplasm pattern recognition receptors exist to sense the attacks from either foreign or host origins, triggering the immune response to battle with the infections. Among them, cGAS-STING is the major pathway that mainly responds to microbial DNA, DNA virus infections, or self-DNA, which mainly comes from genome instability by-product or released DNA from the mitochondria. cGAS was initially found functional in the cytoplasm, although intriguing evidence indicates that cGAS exists in the nucleus where it is involved in the DNA damage repair process. Because the close connection between DNA damage response and immune response and cGAS recognizes DNA in length-dependent but DNA sequence-independent manners, it is urgent to clear the function balance of cGAS in the nucleus versus cytoplasm and how it is shielded from recognizing the host origin DNA. Here, we outline the current conception of immune response and the regulation mechanism of cGAS in the nucleus. Furthermore, we will shed light on the potential mechanisms that are restricted to be taken away from self-DNA recognition, especially how post-translational modification regulates cGAS functions.
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Affiliation(s)
- Jia-Xian Song
- Institute for Translation Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Deana Villagomes
- Department of Molecular and Cellular Biology, University of California Davis, One Shields Avenue, Davis, CA, United States
| | - Hongchang Zhao
- Department of Microbiology and Molecular Genetics, University of California Davis, One Shields Avenue, Davis, CA, United States
| | - Min Zhu
- Institute for Translation Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China,*Correspondence: Min Zhu,
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14
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Műzes G, Bohusné Barta B, Szabó O, Horgas V, Sipos F. Cell-Free DNA in the Pathogenesis and Therapy of Non-Infectious Inflammations and Tumors. Biomedicines 2022; 10:biomedicines10112853. [PMID: 36359370 PMCID: PMC9687442 DOI: 10.3390/biomedicines10112853] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 10/31/2022] [Accepted: 11/07/2022] [Indexed: 11/09/2022] Open
Abstract
The basic function of the immune system is the protection of the host against infections, along with the preservation of the individual antigenic identity. The process of self-tolerance covers the discrimination between self and foreign antigens, including proteins, nucleic acids, and larger molecules. Consequently, a broken immunological self-tolerance results in the development of autoimmune or autoinflammatory disorders. Immunocompetent cells express pattern-recognition receptors on their cell membrane and cytoplasm. The majority of endogenous DNA is located intracellularly within nuclei and mitochondria. However, extracellular, cell-free DNA (cfDNA) can also be detected in a variety of diseases, such as autoimmune disorders and malignancies, which has sparked interest in using cfDNA as a possible biomarker. In recent years, the widespread use of liquid biopsies and the increasing demand for screening, as well as monitoring disease activity and therapy response, have enabled the revival of cfDNA research. The majority of studies have mainly focused on the function of cfDNA as a biomarker. However, research regarding the immunological consequences of cfDNA, such as its potential immunomodulatory or therapeutic benefits, is still in its infancy. This article discusses the involvement of various DNA-sensing receptors (e.g., absent in melanoma-2; Toll-like receptor 9; cyclic GMP-AMP synthase/activator of interferon genes) in identifying host cfDNA as a potent danger-associated molecular pattern. Furthermore, we aim to summarize the results of the experimental studies that we recently performed and highlight the immunomodulatory capacity of cfDNA, and thus, the potential for possible therapeutic consideration.
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Affiliation(s)
| | | | | | | | - Ferenc Sipos
- Correspondence: ; Tel.: +36-20-478-0752; Fax: +36-1-266-0816
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15
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Regulation of cGAS Activity and Downstream Signaling. Cells 2022; 11:cells11182812. [PMID: 36139387 PMCID: PMC9496985 DOI: 10.3390/cells11182812] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/30/2022] Open
Abstract
Cyclic GMP-AMP synthase (cGAS) is a predominant and ubiquitously expressed cytosolic onfirmedDNA sensor that activates innate immune responses by producing a second messenger, cyclic GMP-AMP (cGAMP), and the stimulator of interferon genes (STING). cGAS contains a highly disordered N-terminus, which can sense genomic/chromatin DNA, while the C terminal of cGAS binds dsDNA liberated from various sources, including mitochondria, pathogens, and dead cells. Furthermore, cGAS cellular localization dictates its response to foreign versus self-DNA. Recent evidence has also highlighted the importance of dsDNA-induced post-translational modifications of cGAS in modulating inflammatory responses. This review summarizes and analyzes cGAS activity regulation based on structure, sub-cellular localization, post-translational mechanisms, and Ca2+ signaling. We also discussed the role of cGAS activation in different diseases and clinical outcomes.
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16
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Yao Y, Wang W, Chen C. Mechanisms of phase-separation-mediated cGAS activation revealed by dcFCCS. PNAS NEXUS 2022; 1:pgac109. [PMID: 36741445 PMCID: PMC9896928 DOI: 10.1093/pnasnexus/pgac109] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/02/2022] [Indexed: 02/07/2023]
Abstract
Cyclic GMP-AMP synthase (cGAS), as a DNA sensor, plays an important role in cGAS-STING pathway, which further induces expression of type I interferon as the innate immune response. Previous studies reported that liquid-liquid phase separation (LLPS) driven by cGAS and long DNA is essential to promote catalytic activity of cGAS to produce a second messenger, cyclic GMP-AMP (cGAMP). However, the molecular mechanism of LLPS promoting cGAS activity is still unclear. Here, we applied dual-color fluorescence cross-correlation spectroscopy (dcFCCS), a highly sensitive and quantitative method, to characterize phase separation driven by cGAS and DNA from miscible individual molecule to micronscale. Thus, we captured nanoscale condensates formed by cGAS at close-to-physiological concentration and quantified their sizes, molecular compositions and binding affinities within condensates. Our results pinpointed that interactions between DNA and cGAS at DNA binding sites A, B, and C and the dimerization of cGAS are the fundamental molecular basis to fully activate cGAS in vitro. Due to weak binding constants of these sites, endogenous cGAS cannot form stable interactions at these sites, leading to no activity in the absence of LLPS. Phase separation of cGAS and DNA enriches cGAS and DNA by 2 to 3 orders of magnitude to facilitate these interactions among cGAS and DNA and to promote cGAS activity as an on/off switch. Our discoveries not only shed lights on the molecular mechanisms of phase-separation-mediated cGAS activation, but also guided us to engineer a cGAS fusion, which can be activated by 15 bp short DNA without LLPS.
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Affiliation(s)
- Yirong Yao
- School of Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center of Biological Structure, Tsinghua University, Beijing, 100084, China
| | - Wenjuan Wang
- School of Life Sciences, Technology Center for Protein Sciences, Tsinghua University, Beijing, 100084, China
| | - Chunlai Chen
- School of Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center of Biological Structure, Tsinghua University, Beijing, 100084, China
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17
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Xie B, Luo A. Nucleic Acid Sensing Pathways in DNA Repair Targeted Cancer Therapy. Front Cell Dev Biol 2022; 10:903781. [PMID: 35557952 PMCID: PMC9089908 DOI: 10.3389/fcell.2022.903781] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/08/2022] [Indexed: 12/24/2022] Open
Abstract
The repair of DNA damage is a complex process, which helps to maintain genome fidelity, and the ability of cancer cells to repair therapeutically DNA damage induced by clinical treatments will affect the therapeutic efficacy. In the past decade, great success has been achieved by targeting the DNA repair network in tumors. Recent studies suggest that DNA damage impacts cellular innate and adaptive immune responses through nucleic acid-sensing pathways, which play essential roles in the efficacy of DNA repair targeted therapy. In this review, we summarize the current understanding of the molecular mechanism of innate immune response triggered by DNA damage through nucleic acid-sensing pathways, including DNA sensing via the cyclic GMP-AMP synthase (cGAS), Toll-like receptor 9 (TLR9), absent in melanoma 2 (AIM2), DNA-dependent protein kinase (DNA-PK), and Mre11-Rad50-Nbs1 complex (MRN) complex, and RNA sensing via the TLR3/7/8 and retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs). Furthermore, we will focus on the recent developments in the impacts of nucleic acid-sensing pathways on the DNA damage response (DDR). Elucidating the DDR-immune response interplay will be critical to harness immunomodulatory effects to improve the efficacy of antitumor immunity therapeutic strategies and build future therapeutic approaches.
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Affiliation(s)
- Bingteng Xie
- School of Life Science, Beijing Institute of Technology, Beijing, China.,Key Laboratory of Molecular Medicine and Biological Diagnosis and Treatment, Beijing Institute of Technology, Ministry of Industry and Information Technology, Beijing, China
| | - Aiqin Luo
- School of Life Science, Beijing Institute of Technology, Beijing, China.,Key Laboratory of Molecular Medicine and Biological Diagnosis and Treatment, Beijing Institute of Technology, Ministry of Industry and Information Technology, Beijing, China
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18
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Abstract
Inflammation plays indispensable roles in building the immune responses such as acquired immunity against harmful pathogens. Furthermore, it is essential for maintaining biological homeostasis in ever-changing conditions. Pattern-recognition receptors (PRRs) reside in cell membranes, endosomes or cytoplasm, and function as triggers for inflammatory responses. Binding of pathogen- or self-derived components, such as DNA, to PRRs activates downstream signaling cascades, resulting in the production of a series of pro-inflammatory cytokines and type I interferons (IFNs). While these series of responses are essential for host defense, the unexpected release of DNA from the nucleus or mitochondria of host cells can lead to autoimmune and autoinflammatory diseases. In this review, we focus on DNA-sensing mechanisms via PRRs and the disorders and extraordinary conditions caused by self-derived DNA.
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Affiliation(s)
- Daisuke Ori
- Division of Biological Science, Graduate School of Science and Technology, Laboratory of Molecular Immunobiology, Nara Institute of Science and Technology (NAIST), Ikoma, Japan
| | - Taro Kawai
- Division of Biological Science, Graduate School of Science and Technology, Laboratory of Molecular Immunobiology, Nara Institute of Science and Technology (NAIST), Ikoma, Japan
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19
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Garland KM, Sheehy TL, Wilson JT. Chemical and Biomolecular Strategies for STING Pathway Activation in Cancer Immunotherapy. Chem Rev 2022; 122:5977-6039. [PMID: 35107989 PMCID: PMC8994686 DOI: 10.1021/acs.chemrev.1c00750] [Citation(s) in RCA: 102] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The stimulator of interferon genes (STING) cellular signaling pathway is a promising target for cancer immunotherapy. Activation of the intracellular STING protein triggers the production of a multifaceted array of immunostimulatory molecules, which, in the proper context, can drive dendritic cell maturation, antitumor macrophage polarization, T cell priming and activation, natural killer cell activation, vascular reprogramming, and/or cancer cell death, resulting in immune-mediated tumor elimination and generation of antitumor immune memory. Accordingly, there is a significant amount of ongoing preclinical and clinical research toward further understanding the role of the STING pathway in cancer immune surveillance as well as the development of modulators of the pathway as a strategy to stimulate antitumor immunity. Yet, the efficacy of STING pathway agonists is limited by many drug delivery and pharmacological challenges. Depending on the class of STING agonist and the desired administration route, these may include poor drug stability, immunocellular toxicity, immune-related adverse events, limited tumor or lymph node targeting and/or retention, low cellular uptake and intracellular delivery, and a complex dependence on the magnitude and kinetics of STING signaling. This review provides a concise summary of the STING pathway, highlighting recent biological developments, immunological consequences, and implications for drug delivery. This review also offers a critical analysis of an expanding arsenal of chemical strategies that are being employed to enhance the efficacy, safety, and/or clinical utility of STING pathway agonists and lastly draws attention to several opportunities for therapeutic advancements.
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Affiliation(s)
- Kyle M Garland
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, 37235 United States
| | - Taylor L Sheehy
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, 37235 United States
| | - John T Wilson
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, 37235 United States
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, 37235 United States
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, 37232 United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, Tennessee, 37232 United States
- Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, Tennessee, 37232 United States
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee, 37232 United States
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20
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KURUMIZAKA H. Structural studies of functional nucleosome complexes with transacting factors. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2022; 98:1-14. [PMID: 35013027 PMCID: PMC8795532 DOI: 10.2183/pjab.98.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
In eukaryotic cells, the genomic DNA is hierarchically organized into chromatin. Chromatin structures and dynamics influence all nuclear functions that are guided by DNA, and thus regulate gene expression. Chromatin structure aberrations cause various health issues, such as cancer, lifestyle-related diseases, mental disorders, infertility, congenital diseases, and infectious diseases. Many studies have unveiled the fundamental features and the heterogeneity of the nucleosome, which is the basic repeating unit of chromatin. The nucleosome is the highly conserved primary chromatin architecture in eukaryotes, but it also has structural versatility. Therefore, analyses of these primary chromatin structures will clarify the higher-order chromatin architecture. This review focuses on structural and functional studies of nucleosomes, based on our research accomplishments.
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Affiliation(s)
- Hitoshi KURUMIZAKA
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
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21
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Bao T, Liu J, Leng J, Cai L. The cGAS-STING pathway: more than fighting against viruses and cancer. Cell Biosci 2021; 11:209. [PMID: 34906241 PMCID: PMC8670263 DOI: 10.1186/s13578-021-00724-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 12/02/2021] [Indexed: 01/07/2023] Open
Abstract
In the classic Cyclic guanosine monophosphate–adenosine monophosphate (cGAMP) synthase (cGAS)-stimulator of interferon genes (STING) pathway, downstream signals can control the production of type I interferon and nuclear factor kappa-light-chain-enhancer of activated B cells to promote the activation of pro-inflammatory molecules, which are mainly induced during antiviral responses. However, with progress in this area of research, studies focused on autoimmune diseases and chronic inflammatory conditions that may be relevant to cGAS–STING pathways have been conducted. This review mainly highlights the functions of the cGAS–STING pathway in chronic inflammatory diseases. Importantly, the cGAS–STING pathway has a major impact on lipid metabolism. Different research groups have confirmed that the cGAS–STING pathway plays an important role in the chronic inflammatory status in various organs. However, this pathway has not been studied in depth in diabetes and diabetes-related complications. Current research on the cGAS–STING pathway has shown that the targeted therapy of diseases that may be caused by inflammation via the cGAS–STING pathway has promising outcomes.
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Affiliation(s)
- Terigen Bao
- Department of Geriatrics, The First Hospital of Jilin University, Changchun, 130021, China.,Department of Pediatrics, The Pediatric Research Institute, The University of Louisville School of Medicine, Louisville, KY, 40292, USA
| | - Jia Liu
- Department of Geriatrics, The First Hospital of Jilin University, Changchun, 130021, China
| | - Jiyan Leng
- Department of Geriatrics, The First Hospital of Jilin University, Changchun, 130021, China.
| | - Lu Cai
- Department of Pediatrics, The Pediatric Research Institute, The University of Louisville School of Medicine, Louisville, KY, 40292, USA.,Departments of Pharmacology and Toxicology, The University of Louisville School of Medicine, Louisville, KY, USA
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22
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Garland KM, Rosch JC, Carson CS, Wang-Bishop L, Hanna A, Sevimli S, Van Kaer C, Balko JM, Ascano M, Wilson JT. Pharmacological Activation of cGAS for Cancer Immunotherapy. Front Immunol 2021; 12:753472. [PMID: 34899704 PMCID: PMC8662543 DOI: 10.3389/fimmu.2021.753472] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/29/2021] [Indexed: 01/23/2023] Open
Abstract
When compartmentally mislocalized within cells, nucleic acids can be exceptionally immunostimulatory and can even trigger the immune-mediated elimination of cancer. Specifically, the accumulation of double-stranded DNA in the cytosol can efficiently promote antitumor immunity by activating the cGAMP synthase (cGAS) / stimulator of interferon genes (STING) cellular signaling pathway. Targeting this cytosolic DNA sensing pathway with interferon stimulatory DNA (ISD) is therefore an attractive immunotherapeutic strategy for the treatment of cancer. However, the therapeutic activity of ISD is limited by several drug delivery barriers, including susceptibility to deoxyribonuclease degradation, poor cellular uptake, and inefficient cytosolic delivery. Here, we describe the development of a nucleic acid immunotherapeutic, NanoISD, which overcomes critical delivery barriers that limit the activity of ISD and thereby promotes antitumor immunity through the pharmacological activation of cGAS at the forefront of the STING pathway. NanoISD is a nanoparticle formulation that has been engineered to confer deoxyribonuclease resistance, enhance cellular uptake, and promote endosomal escape of ISD into the cytosol, resulting in potent activation of the STING pathway via cGAS. NanoISD mediates the local production of proinflammatory cytokines via STING signaling. Accordingly, the intratumoral administration of NanoISD induces the infiltration of natural killer cells and T lymphocytes into murine tumors. The therapeutic efficacy of NanoISD is demonstrated in preclinical tumor models by attenuated tumor growth, prolonged survival, and an improved response to immune checkpoint blockade therapy.
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Affiliation(s)
- Kyle M. Garland
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
| | - Jonah C. Rosch
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
| | - Carcia S. Carson
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Lihong Wang-Bishop
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
| | - Ann Hanna
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Sema Sevimli
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
| | - Casey Van Kaer
- Department of Bioengineering, Northeastern University, Boston, MA, United States
| | - Justin M. Balko
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Manuel Ascano
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN, United States
| | - John T. Wilson
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN, United States
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23
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Toll-Like Receptors: General Molecular and Structural Biology. J Immunol Res 2021; 2021:9914854. [PMID: 34195298 PMCID: PMC8181103 DOI: 10.1155/2021/9914854] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/19/2021] [Indexed: 12/11/2022] Open
Abstract
Background/Aim Toll-like receptors (TLRs) are pivotal biomolecules in the immune system. Today, we are all aware of the importance of TLRs in bridging innate and adaptive immune system to each other. The TLRs are activated through binding to damage/danger-associated molecular patterns (DAMPs), microbial/microbe-associated molecular patterns (MAMPs), pathogen-associated molecular patterns (PAMPs), and xenobiotic-associated molecular patterns (XAMPs). The immunogenetic molecules of TLRs have their own functions, structures, coreceptors, and ligands which make them unique. These properties of TLRs give us an opportunity to find out how we can employ this knowledge for ligand-drug discovery strategies to control TLRs functions and contribution, signaling pathways, and indirect activities. Hence, the authors of this paper have a deep observation on the molecular and structural biology of human TLRs (hTLRs). Methods and Materials To prepare this paper and fulfill our goals, different search engines (e.g., GOOGLE SCHOLAR), Databases (e.g., MEDLINE), and websites (e.g., SCOPUS) were recruited to search and find effective papers and investigations. To reach this purpose, we tried with papers published in the English language with no limitation in time. The iCite bibliometrics was exploited to check the quality of the collected publications. Results Each TLR molecule has its own molecular and structural biology, coreceptor(s), and abilities which make them unique or a complementary portion of the others. These immunogenetic molecules have remarkable roles and are much more important in different sections of immune and nonimmune systems rather than that we understand to date. Conclusion TLRs are suitable targets for ligand-drug discovery strategies to establish new therapeutics in the fields of infectious and autoimmune diseases, cancers, and other inflammatory diseases and disorders.
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24
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Zhao Z, Ma Z, Wang B, Guan Y, Su XD, Jiang Z. Mn 2+ Directly Activates cGAS and Structural Analysis Suggests Mn 2+ Induces a Noncanonical Catalytic Synthesis of 2'3'-cGAMP. Cell Rep 2021; 32:108053. [PMID: 32814054 DOI: 10.1016/j.celrep.2020.108053] [Citation(s) in RCA: 141] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/10/2020] [Accepted: 07/29/2020] [Indexed: 01/09/2023] Open
Abstract
DNA binding allosterically activates the cytosolic DNA sensor cGAS (cyclic GMP-AMP [cGAMP] synthase) to synthesize 2'3'-cGAMP, using Mg2+ as the metal cofactor that catalyzes two nucleotidyl-transferring reactions. We previously found that Mn2+ potentiates cGAS activation, but the underlying mechanism remains unclear. Here, we report that Mn2+ directly activates cGAS. Structural analysis reveals that Mn2+-activated cGAS undergoes globally similar conformational changes to DNA-activated cGAS but forms a unique η1 helix to widen the catalytic pocket, allowing substrate entry and cGAMP synthesis. Strikingly, in Mn2+-activated cGAS, the linear intermediates pppGpG and pGpA take an inverted orientation in the active pocket, suggesting a noncanonical but accelerated cGAMP cyclization without substrate flip-over. Moreover, unlike the octahedral coordination around Mg2+, the two catalytic Mn2+ are coordinated by triphosphate moiety of the inverted substrate, independent of the catalytic triad residues. Our findings thus uncover Mn2+ as a cGAS activator that initiates noncanonical 2'3'-cGAMP synthesis.
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Affiliation(s)
- Zhen Zhao
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Zhixing Ma
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Bo Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China; Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing 100871, China
| | - Yukun Guan
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xiao-Dong Su
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China; Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing 100871, China.
| | - Zhengfan Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
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25
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Ko TP, Wang YC, Tsai CL, Yang CS, Hou MH, Chen Y. Crystal structure and functional implication of a bacterial cyclic AMP-AMP-GMP synthetase. Nucleic Acids Res 2021; 49:4725-4737. [PMID: 33836064 PMCID: PMC8096243 DOI: 10.1093/nar/gkab165] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/24/2021] [Accepted: 04/07/2021] [Indexed: 01/10/2023] Open
Abstract
Mammalian cyclic GMP-AMP synthase (cGAS) and its homologue dinucleotide cyclase in Vibrio cholerae (VcDncV) produce cyclic dinucleotides (CDNs) that participate in the defense against viral infection. Recently, scores of new cGAS/DncV-like nucleotidyltransferases (CD-NTases) were discovered, which produce various CDNs and cyclic trinucleotides (CTNs) as second messengers. Here, we present the crystal structures of EcCdnD, a CD-NTase from Enterobacter cloacae that produces cyclic AMP-AMP-GMP, in its apo-form and in complex with ATP, ADP and AMPcPP, an ATP analogue. Despite the similar overall architecture, the protein shows significant structural variations from other CD-NTases. Adjacent to the donor substrate, another nucleotide is bound to the acceptor binding site by a non-productive mode. Isothermal titration calorimetry results also suggest the presence of two ATP binding sites. GTP alone does not bind to EcCdnD, which however binds to pppApG, a possible intermediate. The enzyme is active on ATP or a mixture of ATP and GTP, and the best metal cofactor is Mg2+. The conserved residues Asp69 and Asp71 are essential for catalysis, as indicated by the loss of activity in the mutants. Based on structural analysis and comparison with VcDncV and RNA polymerase, a tentative catalytic pathway for the CTN-producing EcCdnD is proposed.
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Affiliation(s)
- Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Yu-Chuan Wang
- Institute of New Drug Development, China Medical University, Taichung 406, Taiwan
| | - Chia-Ling Tsai
- Institute of New Drug Development, China Medical University, Taichung 406, Taiwan
| | - Chia-Shin Yang
- Institute of New Drug Development, China Medical University, Taichung 406, Taiwan
| | - Mei-Hui Hou
- Institute of New Drug Development, China Medical University, Taichung 406, Taiwan
| | - Yeh Chen
- Institute of New Drug Development, China Medical University, Taichung 406, Taiwan
- Research Center for Cancer Biology, China Medical University, Taichung 406, Taiwan
- New Drug Development Center, China Medical University, Taichung 406, Taiwan
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26
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Li C, Zhang L, Qian D, Cheng M, Hu H, Hong Z, Cui Y, Yu H, Wang Q, Zhu J, Meng W, Xu JF, Sun Y, Zhang P, Wang C. RNF111-facilitated neddylation potentiates cGAS-mediated antiviral innate immune response. PLoS Pathog 2021; 17:e1009401. [PMID: 33720974 PMCID: PMC7959372 DOI: 10.1371/journal.ppat.1009401] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 02/17/2021] [Indexed: 12/15/2022] Open
Abstract
The cytosolic DNA sensor cyclic GMP-AMP (cGAMP) synthetase (cGAS) has emerged as a fundamental component fueling the anti-pathogen immunity. Because of its pivotal role in initiating innate immune response, the activity of cGAS must be tightly fine-tuned to maintain immune homeostasis in antiviral response. Here, we reported that neddylation modification was indispensable for appropriate cGAS-STING signaling activation. Blocking neddylation pathway using neddylation inhibitor MLN4924 substantially impaired the induction of type I interferon and proinflammatory cytokines, which was selectively dependent on Nedd8 E2 enzyme Ube2m. We further found that deficiency of the Nedd8 E3 ligase Rnf111 greatly attenuated DNA-triggered cGAS activation while not affecting cGAMP induced activation of STING, demonstrating that Rnf111 was the Nedd8 E3 ligase of cGAS. By performing mass spectrometry, we identified Lys231 and Lys421 as essential neddylation sites in human cGAS. Mechanistically, Rnf111 interacted with and polyneddylated cGAS, which in turn promoted its dimerization and enhanced the DNA-binding ability, leading to proper cGAS-STING pathway activation. In the same line, the Ube2m or Rnf111 deficiency mice exhibited severe defects in innate immune response and were susceptible to HSV-1 infection. Collectively, our study uncovered a vital role of the Ube2m-Rnf111 neddylation axis in promoting the activity of the cGAS-STING pathway and highlighted the importance of neddylation modification in antiviral defense.
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Affiliation(s)
- Chenhui Li
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Lele Zhang
- Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China
| | - Dong Qian
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Mingxing Cheng
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Haiyang Hu
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Ze Hong
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Ye Cui
- Division of Immunology, The Boston Children’s Hospital, Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Huansha Yu
- Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China
| | - Quanyi Wang
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Juanjuan Zhu
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Wei Meng
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Jin-fu Xu
- Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yi Sun
- Cancer Institute of the 2 affiliated hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- * E-mail: (YS); (PZ); (CW)
| | - Peng Zhang
- Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China
- * E-mail: (YS); (PZ); (CW)
| | - Chen Wang
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, China
- * E-mail: (YS); (PZ); (CW)
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27
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Zhou W, Mohr L, Maciejowski J, Kranzusch PJ. cGAS phase separation inhibits TREX1-mediated DNA degradation and enhances cytosolic DNA sensing. Mol Cell 2021; 81:739-755.e7. [PMID: 33606975 DOI: 10.1016/j.molcel.2021.01.024] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 12/30/2020] [Accepted: 01/19/2021] [Indexed: 12/17/2022]
Abstract
Cyclic GMP-AMP synthase (cGAS) recognition of cytosolic DNA is critical for the immune response to cancer and pathogen infection. Here, we discover that cGAS-DNA phase separation is required to resist negative regulation and allow efficient sensing of immunostimulatory DNA. We map the molecular determinants of cGAS condensate formation and demonstrate that phase separation functions to limit activity of the cytosolic exonuclease TREX1. Mechanistically, phase separation forms a selective environment that suppresses TREX1 catalytic function and restricts DNA degradation to an outer shell at the droplet periphery. We identify a TREX1 mutation associated with the severe autoimmune disease Aicardi-Goutières syndrome that increases penetration of TREX1 into the repressive droplet interior and specifically impairs degradation of phase-separated DNA. Our results define a critical function of cGAS-DNA phase separation and reveal a molecular mechanism that balances cytosolic DNA degradation and innate immune activation.
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Affiliation(s)
- Wen Zhou
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Lisa Mohr
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - John Maciejowski
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Philip J Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, MA 02115, USA.
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28
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Kumar V. The Trinity of cGAS, TLR9, and ALRs Guardians of the Cellular Galaxy Against Host-Derived Self-DNA. Front Immunol 2021; 11:624597. [PMID: 33643304 PMCID: PMC7905024 DOI: 10.3389/fimmu.2020.624597] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022] Open
Abstract
The immune system has evolved to protect the host from the pathogens and allergens surrounding their environment. The immune system develops in such a way to recognize self and non-self and develops self-tolerance against self-proteins, nucleic acids, and other larger molecules. However, the broken immunological self-tolerance leads to the development of autoimmune or autoinflammatory diseases. Pattern-recognition receptors (PRRs) are expressed by immunological cells on their cell membrane and in the cytosol. Different Toll-like receptors (TLRs), Nod-like receptors (NLRs) and absent in melanoma-2 (AIM-2)-like receptors (ALRs) forming inflammasomes in the cytosol, RIG (retinoic acid-inducible gene)-1-like receptors (RLRs), and C-type lectin receptors (CLRs) are some of the PRRs. The DNA-sensing receptor cyclic GMP–AMP synthase (cGAS) is another PRR present in the cytosol and the nucleus. The present review describes the role of ALRs (AIM2), TLR9, and cGAS in recognizing the host cell DNA as a potent damage/danger-associated molecular pattern (DAMP), which moves out to the cytosol from its housing organelles (nucleus and mitochondria). The introduction opens with the concept that the immune system has evolved to recognize pathogens, the idea of horror autotoxicus, and its failure due to the emergence of autoimmune diseases (ADs), and the discovery of PRRs revolutionizing immunology. The second section describes the cGAS-STING signaling pathway mediated cytosolic self-DNA recognition, its evolution, characteristics of self-DNAs activating it, and its role in different inflammatory conditions. The third section describes the role of TLR9 in recognizing self-DNA in the endolysosomes during infections depending on the self-DNA characteristics and various inflammatory diseases. The fourth section discusses about AIM2 (an ALR), which also binds cytosolic self-DNA (with 80–300 base pairs or bp) that inhibits cGAS-STING-dependent type 1 IFN generation but induces inflammation and pyroptosis during different inflammatory conditions. Hence, this trinity of PRRs has evolved to recognize self-DNA as a potential DAMP and comes into action to guard the cellular galaxy. However, their dysregulation proves dangerous to the host and leads to several inflammatory conditions, including sterile-inflammatory conditions autoinflammatory and ADs.
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Affiliation(s)
- Vijay Kumar
- Children's Health Queensland Clinical Unit, School of Clinical Medicine, Faculty of Medicine, Mater Research, University of Queensland, St. Lucia, Brisbane, QLD, Australia.,School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, Brisbane, QLD, Australia
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29
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Okude H, Ori D, Kawai T. Signaling Through Nucleic Acid Sensors and Their Roles in Inflammatory Diseases. Front Immunol 2021; 11:625833. [PMID: 33633744 PMCID: PMC7902034 DOI: 10.3389/fimmu.2020.625833] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/14/2020] [Indexed: 12/14/2022] Open
Abstract
Recognition of pathogen-derived nucleic acids by pattern-recognition receptors (PRRs) is essential for eliciting antiviral immune responses by inducing the production of type I interferons (IFNs) and proinflammatory cytokines. Such responses are a prerequisite for mounting innate and pathogen-specific adaptive immune responses. However, host cells also use nucleic acids as carriers of genetic information, and the aberrant recognition of self-nucleic acids by PRRs is associated with the onset of autoimmune or autoinflammatory diseases. In this review, we describe the mechanisms of nucleic acid sensing by PRRs, including Toll-like receptors, RIG-I-like receptors, and DNA sensor molecules, and their signaling pathways as well as the disorders caused by uncontrolled or unnecessary activation of these PRRs.
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Affiliation(s)
- Haruna Okude
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Japan
| | - Daisuke Ori
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Japan
| | - Taro Kawai
- Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Ikoma, Japan
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30
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Sun X, Liu T, Zhao J, Xia H, Xie J, Guo Y, Zhong L, Li M, Yang Q, Peng C, Rouvet I, Belot A, Shu HB, Feng P, Zhang J. DNA-PK deficiency potentiates cGAS-mediated antiviral innate immunity. Nat Commun 2020; 11:6182. [PMID: 33273464 PMCID: PMC7712783 DOI: 10.1038/s41467-020-19941-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 11/09/2020] [Indexed: 02/08/2023] Open
Abstract
Upon sensing cytosolic DNA, the enzyme cGAS induces innate immune responses that underpin anti-microbial defenses and certain autoimmune diseases. Missense mutations of PRKDC encoding the DNA-dependent protein kinase (DNA-PK) catalytic subunit (DNA-PKcs) are associated with autoimmune diseases, yet how DNA-PK deficiency leads to increased immune responses remains poorly understood. In this study, we report that DNA-PK phosphorylates cGAS and suppresses its enzymatic activity. DNA-PK deficiency reduces cGAS phosphorylation and promotes antiviral innate immune responses, thereby potently restricting viral replication. Moreover, cells isolated from DNA-PKcs-deficient mice or patients carrying PRKDC missense mutations exhibit an inflammatory gene expression signature. This study provides a rational explanation for the autoimmunity of patients with missense mutations of PRKDC, and suggests that cGAS-mediated immune signaling is a potential target for therapeutic interventions.
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Affiliation(s)
- Xiaona Sun
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, State Key Laboratory of Virology, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Ting Liu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, State Key Laboratory of Virology, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Jun Zhao
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
| | - Hansong Xia
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
- Department of Orthopaedics, 3rd Xiangya Hospital, Central South University, Changsha, China
| | - Jun Xie
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, State Key Laboratory of Virology, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Yu Guo
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, State Key Laboratory of Virology, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Li Zhong
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Mi Li
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Qing Yang
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Cheng Peng
- Department of Burns and Plastic Surgery, 3rd Xiangya Hospital, Central South University, Changsha, China
| | - Isabelle Rouvet
- Hospices Civils de Lyon, Centre de Biotechnologie Cellulaire et Biothèque, Bron, France
| | - Alexandre Belot
- Centre International de Recherche en Infectiologie, CIRI, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, École Normale Supérieure de Lyon, University of Lyon, Lyon, France
- National Referee Centre for Pediatric-Onset Rheumatism and Autoimmune Diseases (RAISE), Lyon, France
- Hospices Civils de Lyon, Paediatric Nephrology, Rheumatology, Dermatology Unit, Mother and Children University Hospital, Bron, France
| | - Hong-Bing Shu
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China
| | - Pinghui Feng
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA.
| | - Junjie Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, State Key Laboratory of Virology, Wuhan University, Wuhan, China.
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, China.
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31
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Hertzog J, Rehwinkel J. Regulation and inhibition of the DNA sensor cGAS. EMBO Rep 2020; 21:e51345. [PMID: 33155371 PMCID: PMC7726805 DOI: 10.15252/embr.202051345] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/01/2020] [Accepted: 10/14/2020] [Indexed: 12/13/2022] Open
Abstract
Cell-autonomous sensing of nucleic acids is essential for host defence against invading pathogens by inducing antiviral and inflammatory cytokines. cGAS has emerged in recent years as a non-redundant DNA sensor important for detection of many viruses and bacteria. Upon binding to DNA, cGAS synthesises the cyclic dinucleotide 2'3'-cGAMP that binds to the adaptor protein STING and thereby triggers IRF3- and NFκB-dependent transcription. In addition to infection, the pathophysiology of an ever-increasing number of sterile inflammatory conditions in humans involves the recognition of DNA through cGAS. Consequently, the cGAS/STING signalling axis has emerged as an attractive target for pharmacological modulation. However, the development of cGAS and STING inhibitors has just begun and a need for specific and effective compounds persists. In this review, we focus on cGAS and explore how its activation by immunostimulatory DNA is regulated by cellular mechanisms, viral immune modulators and small molecules. We further use our knowledge of cGAS modulation by cells and viruses to conceptualise potential new ways of pharmacological cGAS targeting.
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Affiliation(s)
- Jonny Hertzog
- MRC Human Immunology UnitMRC Weatherall Institute of Molecular MedicineRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Jan Rehwinkel
- MRC Human Immunology UnitMRC Weatherall Institute of Molecular MedicineRadcliffe Department of MedicineUniversity of OxfordOxfordUK
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32
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Kujirai T, Zierhut C, Takizawa Y, Kim R, Negishi L, Uruma N, Hirai S, Funabiki H, Kurumizaka H. Structural basis for the inhibition of cGAS by nucleosomes. Science 2020; 370:455-458. [PMID: 32912999 DOI: 10.1126/science.abd0237] [Citation(s) in RCA: 143] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/28/2020] [Indexed: 12/19/2022]
Abstract
The cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) senses invasion of pathogenic DNA and stimulates inflammatory signaling, autophagy, and apoptosis. Organization of host DNA into nucleosomes was proposed to limit cGAS autoinduction, but the underlying mechanism was unknown. Here, we report the structural basis for this inhibition. In the cryo-electron microscopy structure of the human cGAS-nucleosome core particle (NCP) complex, two cGAS monomers bridge two NCPs by binding the acidic patch of the histone H2A-H2B dimer and nucleosomal DNA. In this configuration, all three known cGAS DNA binding sites, required for cGAS activation, are repurposed or become inaccessible, and cGAS dimerization, another prerequisite for activation, is inhibited. Mutating key residues linking cGAS and the acidic patch alleviates nucleosomal inhibition. This study establishes a structural framework for why cGAS is silenced on chromatinized self-DNA.
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Affiliation(s)
- Tomoya Kujirai
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Christian Zierhut
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Yoshimasa Takizawa
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Ryan Kim
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065, USA
| | - Lumi Negishi
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Nobuki Uruma
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.,Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Seiya Hirai
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Hironori Funabiki
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065, USA.
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan. .,Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
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33
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Michalski S, de Oliveira Mann CC, Stafford CA, Witte G, Bartho J, Lammens K, Hornung V, Hopfner KP. Structural basis for sequestration and autoinhibition of cGAS by chromatin. Nature 2020; 587:678-682. [PMID: 32911480 DOI: 10.1038/s41586-020-2748-0] [Citation(s) in RCA: 139] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/24/2020] [Indexed: 01/14/2023]
Abstract
Cyclic GMP-AMP synthase (cGAS) is an innate immune sensor for cytosolic microbial DNA1. After binding DNA, cGAS synthesizes the messenger 2'3'-cyclic GMP-AMP (cGAMP)2-4, which triggers cell-autonomous defence and the production of type I interferons and pro-inflammatory cytokines via the activation of STING5. In addition to responding to cytosolic microbial DNA, cGAS also recognizes mislocalized cytosolic self-DNA and has been implicated in autoimmunity and sterile inflammation6,7. Specificity towards pathogen- or damage-associated DNA was thought to be caused by cytosolic confinement. However, recent findings place cGAS robustly in the nucleus8-10, where tight tethering of chromatin is important to prevent autoreactivity to self-DNA8. Here we show how cGAS is sequestered and inhibited by chromatin. We provide a cryo-electron microscopy structure of the cGAS catalytic domain bound to a nucleosome, which shows that cGAS does not interact with the nucleosomal DNA, but instead interacts with histone 2A-histone 2B, and is tightly anchored to the 'acidic patch'. The interaction buries the cGAS DNA-binding site B, and blocks the formation of active cGAS dimers. The acidic patch robustly outcompetes agonistic DNA for binding to cGAS, which suggests that nucleosome sequestration can efficiently inhibit cGAS, even when accessible DNA is nearby, such as in actively transcribed genomic regions. Our results show how nuclear cGAS is sequestered by chromatin and provides a mechanism for preventing autoreactivity to nuclear self-DNA.
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Affiliation(s)
- Sebastian Michalski
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Carina C de Oliveira Mann
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Che A Stafford
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Gregor Witte
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Joseph Bartho
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Katja Lammens
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Veit Hornung
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
| | - Karl-Peter Hopfner
- Gene Center, Ludwig-Maximilians-Universität, Munich, Germany. .,Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany.
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34
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Ma R, Ortiz Serrano TP, Davis J, Prigge AD, Ridge KM. The cGAS-STING pathway: The role of self-DNA sensing in inflammatory lung disease. FASEB J 2020; 34:13156-13170. [PMID: 32860267 PMCID: PMC8121456 DOI: 10.1096/fj.202001607r] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/31/2020] [Accepted: 08/05/2020] [Indexed: 12/15/2022]
Abstract
The presence of DNA in the cytosol is usually a sign of microbial infections, which alerts the host innate immune system to mount a defense response. Cyclic GMP-AMP synthase (cGAS) is a critical cytosolic DNA sensor that elicits robust innate immune responses through the production of the second messenger, cyclic GMP-AMP (cGAMP), which binds and activates stimulator of interferon genes (STING). However, cGAS binds to DNA irrespective of DNA sequence, therefore, self-DNA leaked from the nucleus or mitochondria can also serve as a cGAS ligand to activate this pathway and trigger extensive inflammatory responses. Dysregulation of the cGAS-STING pathway is responsible for a broad array of inflammatory and autoimmune diseases. Recently, evidence has shown that self-DNA release and cGAS-STING pathway over-activation can drive lung disease, making this pathway a promising therapeutic target for inflammatory lung disease. Here, we review recent advances on the cGAS-STING pathway governing self-DNA sensing, highlighting its role in pulmonary disease.
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Affiliation(s)
- Ruihua Ma
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Tatiana P Ortiz Serrano
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Jennifer Davis
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Andrew D Prigge
- Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Karen M Ridge
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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35
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Bartok E, Hartmann G. Immune Sensing Mechanisms that Discriminate Self from Altered Self and Foreign Nucleic Acids. Immunity 2020; 53:54-77. [PMID: 32668228 PMCID: PMC7359798 DOI: 10.1016/j.immuni.2020.06.014] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/19/2022]
Abstract
All lifeforms have developed highly sophisticated systems equipped to detect altered self and non-self nucleic acids (NA). In vertebrates, NA-sensing receptors safeguard the integrity of the organism by detecting pathogens, dyshomeostasis and damage, and inducing appropriate responses to eliminate pathogens and reconstitute homeostasis. Effector mechanisms include i) immune signaling, ii) restriction of NA functions such as inhibition of mRNA translation, and iii) cell death pathways. An appropriate effector response is necessary for host defense, but dysregulated NA-sensing can lead to devastating autoimmune and autoinflammatory disease. Their inherent biochemical similarity renders the reliable distinction between self NA under homeostatic conditions and altered or exogenous NA particularly challenging. In this review, we provide an overview of recent progress in our understanding of the closely coordinated and regulated network of innate immune receptors, restriction factors, and nucleases to effectively respond to pathogens and maintain host integrity.
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Affiliation(s)
- Eva Bartok
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Gunther Hartmann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
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36
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Zhao W, Xiong M, Yuan X, Li M, Sun H, Xu Y. In Silico Screening-Based Discovery of Novel Inhibitors of Human Cyclic GMP-AMP Synthase: A Cross-Validation Study of Molecular Docking and Experimental Testing. J Chem Inf Model 2020; 60:3265-3276. [PMID: 32459092 DOI: 10.1021/acs.jcim.0c00171] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cyclic GMP-AMP synthase (cGAS) has been recently uncovered to be a promising therapeutic target for immune-associated diseases. Until now, only a few inhibitors have been identified through high-throughput screening campaigns. Here, we reported the discovery of novel inhibitors for the catalytic domain of human cGAS (h-cGASCD) by virtual screening for the first time. To generate a reliable docking mode, we first obtained a high-resolution crystal structure of h-cGASCD in complex with PF-06928215, a known inhibitor of h-cGAS, followed by molecular dynamics simulations on this complex structure. Four fragment hits were identified by the virtual screening together with a thermal shift assay. The crystal structures of these four compounds in complex with h-cGASCD were subsequently determined, and the binding modes of the compounds were similar to those predicted by molecular docking, supporting the reliability of the docking model. In addition, an enzyme activity assay identified compound 18 (IC50 = 29.88 ± 3.20 μM) from the compounds predicted by the virtual screening. A similarity search of compound 18 followed by a second virtual screening led to the discovery of compounds S2 (IC50 = 13.1 ± 0.09 μM) and S3 (IC50 = 4.9 ± 0.26 μM) as h-cGAS inhibitors with improved potency. Therefore, the present study not only provides the validated hit compounds for further development of h-cGAS inhibitors but also demonstrates a cross-validation study of virtual screening, in vitro experimental assays, and crystal structure determination.
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Affiliation(s)
- Wenfeng Zhao
- Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, P.R. China.,CAS Key Laboratory of Receptor Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Muya Xiong
- CAS Key Laboratory of Receptor Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaojing Yuan
- CAS Key Laboratory of Receptor Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Minjun Li
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Hongbin Sun
- Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, P.R. China
| | - Yechun Xu
- CAS Key Laboratory of Receptor Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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37
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Hopfner KP, Hornung V. Molecular mechanisms and cellular functions of cGAS-STING signalling. Nat Rev Mol Cell Biol 2020; 21:501-521. [PMID: 32424334 DOI: 10.1038/s41580-020-0244-x] [Citation(s) in RCA: 913] [Impact Index Per Article: 228.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2020] [Indexed: 02/07/2023]
Abstract
The cGAS-STING signalling axis, comprising the synthase for the second messenger cyclic GMP-AMP (cGAS) and the cyclic GMP-AMP receptor stimulator of interferon genes (STING), detects pathogenic DNA to trigger an innate immune reaction involving a strong type I interferon response against microbial infections. Notably however, besides sensing microbial DNA, the DNA sensor cGAS can also be activated by endogenous DNA, including extranuclear chromatin resulting from genotoxic stress and DNA released from mitochondria, placing cGAS-STING as an important axis in autoimmunity, sterile inflammatory responses and cellular senescence. Initial models assumed that co-localization of cGAS and DNA in the cytosol defines the specificity of the pathway for non-self, but recent work revealed that cGAS is also present in the nucleus and at the plasma membrane, and such subcellular compartmentalization was linked to signalling specificity of cGAS. Further confounding the simple view of cGAS-STING signalling as a response mechanism to infectious agents, both cGAS and STING were shown to have additional functions, independent of interferon response. These involve non-catalytic roles of cGAS in regulating DNA repair and signalling via STING to NF-κB and MAPK as well as STING-mediated induction of autophagy and lysosome-dependent cell death. We have also learnt that cGAS dimers can multimerize and undergo liquid-liquid phase separation to form biomolecular condensates that could importantly regulate cGAS activation. Here, we review the molecular mechanisms and cellular functions underlying cGAS-STING activation and signalling, particularly highlighting the newly emerging diversity of this signalling pathway and discussing how the specificity towards normal, damage-induced and infection-associated DNA could be achieved.
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Affiliation(s)
- Karl-Peter Hopfner
- Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany. .,Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.
| | - Veit Hornung
- Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany. .,Gene Center, Ludwig-Maximilians-Universität, Munich, Germany.
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38
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Hooy RM, Massaccesi G, Rousseau KE, Chattergoon MA, Sohn J. Allosteric coupling between Mn2+ and dsDNA controls the catalytic efficiency and fidelity of cGAS. Nucleic Acids Res 2020; 48:4435-4447. [PMID: 32170294 PMCID: PMC7192592 DOI: 10.1093/nar/gkaa084] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/24/2020] [Accepted: 03/11/2020] [Indexed: 12/21/2022] Open
Abstract
Cyclic-G/AMP (cGAMP) synthase (cGAS) triggers host innate immune responses against cytosolic double-stranded (ds)DNA arising from genotoxic stress and pathogen invasion. The canonical activation mechanism of cGAS entails dsDNA-binding and dimerization. Here, we report an unexpected activation mechanism of cGAS in which Mn2+ activates monomeric cGAS without dsDNA. Importantly, the Mn2+-mediated activation positively couples with dsDNA-dependent activation in a concerted manner. Moreover, the positive coupling between Mn2+ and dsDNA length-dependent activation requires the cognate ATP/GTP substrate pair, while negative-cooperativity suppresses Mn2+ utilization by either ATP or GTP alone. Additionally, while Mn2+ accelerates the overall catalytic activity, dsDNA length-dependent dimerization specifically accelerates the cyclization of cGAMP. Together, we demonstrate how the intrinsic allostery of cGAS efficiently yet precisely tunes its activity.
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Affiliation(s)
- Richard M Hooy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Guido Massaccesi
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kimberly E Rousseau
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael A Chattergoon
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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39
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Saeed AFUH, Ruan X, Guan H, Su J, Ouyang S. Regulation of cGAS-Mediated Immune Responses and Immunotherapy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1902599. [PMID: 32195086 PMCID: PMC7080523 DOI: 10.1002/advs.201902599] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 01/14/2020] [Indexed: 05/08/2023]
Abstract
Early detection of infectious nucleic acids released from invading pathogens by the innate immune system is critical for immune defense. Detection of these nucleic acids by host immune sensors and regulation of DNA sensing pathways have been significant interests in the past years. Here, current understandings of evolutionarily conserved DNA sensing cyclic GMP-AMP (cGAMP) synthase (cGAS) are highlighted. Precise activation and tight regulation of cGAS are vital in appropriate innate immune responses, senescence, tumorigenesis and immunotherapy, and autoimmunity. Hence, substantial insights into cytosolic DNA sensing and immunotherapy of indispensable cytosolic sensors have been detailed to extend limited knowledge available thus far. This Review offers a critical, in-depth understanding of cGAS regulation, cytosolic DNA sensing, and currently established therapeutic approaches of essential cytosolic immune agents for improved human health.
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Affiliation(s)
- Abdullah F. U. H. Saeed
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Fujian Key Laboratory of Special Marine Bio‐resources Sustainable UtilizationThe Public Service Platform for Industrialization Development Technology of Marine Biological Medicine and Product of State Oceanic AdministrationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao266237China
- College of Chemistry and Materials ScienceFujian Normal UniversityFuzhou350117China
| | - Xinglin Ruan
- Department of NeurologyFujian Medical University Union Hospital29 Xinquan Road Gulou DistrictFuzhou350001China
| | - Hongxin Guan
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Fujian Key Laboratory of Special Marine Bio‐resources Sustainable UtilizationThe Public Service Platform for Industrialization Development Technology of Marine Biological Medicine and Product of State Oceanic AdministrationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
| | - Jingqian Su
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Fujian Key Laboratory of Special Marine Bio‐resources Sustainable UtilizationThe Public Service Platform for Industrialization Development Technology of Marine Biological Medicine and Product of State Oceanic AdministrationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
| | - Songying Ouyang
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Fujian Key Laboratory of Special Marine Bio‐resources Sustainable UtilizationThe Public Service Platform for Industrialization Development Technology of Marine Biological Medicine and Product of State Oceanic AdministrationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao266237China
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40
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Ablasser A, Hur S. Regulation of cGAS- and RLR-mediated immunity to nucleic acids. Nat Immunol 2020; 21:17-29. [PMID: 31819255 DOI: 10.1038/s41590-019-0556-1] [Citation(s) in RCA: 199] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 10/29/2019] [Indexed: 12/13/2022]
Abstract
Pathogen-derived nucleic acids are crucial signals for innate immunity. Despite the structural similarity between those and host nucleic acids, mammalian cells have been able to evolve powerful innate immune signaling pathways that originate from the detection of cytosolic nucleic acid species, one of the most prominent being the cGAS-STING pathway for DNA and the RLR-MAVS pathway for RNA, respectively. Recent advances have revealed a plethora of regulatory mechanisms that are crucial for balancing the activity of nucleic acid sensors for the maintenance of overall cellular homeostasis. Elucidation of the various mechanisms that enable cells to maintain control over the activity of cytosolic nucleic acid sensors has provided new insight into the pathology of human diseases and, at the same time, offers a rich and largely unexplored source for new therapeutic targets. This Review addresses the emerging literature on regulation of the sensing of cytosolic DNA and RNA via cGAS and RLRs.
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Affiliation(s)
- Andrea Ablasser
- Global Health Institute, Swiss Federal Institute of Technology, Lausanne, Switzerland.
| | - Sun Hur
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.
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41
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Kranzusch PJ. cGAS and CD-NTase enzymes: structure, mechanism, and evolution. Curr Opin Struct Biol 2019; 59:178-187. [PMID: 31593902 PMCID: PMC7127440 DOI: 10.1016/j.sbi.2019.08.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 07/25/2019] [Accepted: 08/25/2019] [Indexed: 01/22/2023]
Abstract
Cyclic GMP-AMP synthase (cGAS) is a signaling enzyme in human cells that controls immune-sensing of cytosolic DNA. The recent discoveries of diverse structural homologs of cGAS in animals and bacteria reveal that cGAS-like signaling is surprisingly ancient and widespread in biology. Together with the Vibrio cholerae protein dinucleotide cyclase in Vibrio (DncV), cGAS and DncV homologs comprise a family of cGAS/DncV-like nucleotidyltransferase (CD-NTase) enzymes that synthesize noncanonical RNA signals including cyclic dinucleotides, cyclic trinucleotides, and linear oligonucleotides. Structural and biochemical breakthroughs provide a framework to understand how CD-NTase signaling allows cells to respond to changing environmental conditions. The CD-NTase family also includes uncharacterized human genes like MB21D2 and Mab21L1, highlighting emerging functions of cGAS-like signaling beyond innate immunity.
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Affiliation(s)
- Philip J Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, MA 02115, USA.
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42
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Cadena C, Hur S. Filament-like Assemblies of Intracellular Nucleic Acid Sensors: Commonalities and Differences. Mol Cell 2019; 76:243-254. [PMID: 31626748 PMCID: PMC6880955 DOI: 10.1016/j.molcel.2019.09.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/13/2019] [Accepted: 09/19/2019] [Indexed: 12/25/2022]
Abstract
Self versus non-self discrimination by innate immune sensors is critical for mounting effective immune responses against pathogens while avoiding harmful auto-inflammatory reactions against the host. Foreign DNA and RNA sensors must discriminate between self versus non-self nucleic acids, despite their shared building blocks and similar physicochemical properties. Recent structural and biochemical studies suggest that multiple steps of filament-like assembly are required for the functions of several nucleic acid sensors. Here, we discuss ligand discrimination and oligomerization of RIG-I-like receptors, AIM2-like receptors, and cGAS. We discuss how filament-like assembly allows for robust and accurate discrimination of self versus non-self nucleic acids and how these assemblies enable sensing of multiple distinct features in foreign nucleic acids, including structure, length, and modifications. We also discuss how individual receptors differ in their assembly and disassembly mechanisms and how these differences contribute to the diversity in nucleic acid specificity and pathogen detection strategies.
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Affiliation(s)
- Cristhian Cadena
- Program in Virology, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, MA 02115, USA
| | - Sun Hur
- Program in Virology, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, MA 02115, USA.
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43
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Jiang H, Xue X, Panda S, Kawale A, Hooy RM, Liang F, Sohn J, Sung P, Gekara NO. Chromatin-bound cGAS is an inhibitor of DNA repair and hence accelerates genome destabilization and cell death. EMBO J 2019; 38:e102718. [PMID: 31544964 PMCID: PMC6826206 DOI: 10.15252/embj.2019102718] [Citation(s) in RCA: 178] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/19/2019] [Accepted: 09/02/2019] [Indexed: 12/19/2022] Open
Abstract
DNA repair via homologous recombination (HR) is indispensable for genome integrity and cell survival but if unrestrained can result in undesired chromosomal rearrangements. The regulatory mechanisms of HR are not fully understood. Cyclic GMP-AMP synthase (cGAS) is best known as a cytosolic innate immune sensor critical for the outcome of infections, inflammatory diseases, and cancer. Here, we report that cGAS is primarily a chromatin-bound protein that inhibits DNA repair by HR, thereby accelerating genome destabilization, micronucleus generation, and cell death under conditions of genomic stress. This function is independent of the canonical STING-dependent innate immune activation and is physiologically relevant for irradiation-induced depletion of bone marrow cells in mice. Mechanistically, we demonstrate that inhibition of HR repair by cGAS is linked to its ability to self-oligomerize, causing compaction of bound template dsDNA into a higher-ordered state less amenable to strand invasion by RAD51-coated ssDNA filaments. This previously unknown role of cGAS has implications for understanding its involvement in genome instability-associated disorders including cancer.
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Affiliation(s)
- Hui Jiang
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Xiaoyu Xue
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA.,Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA
| | - Swarupa Panda
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
| | - Ajinkya Kawale
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
| | - Richard M Hooy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Fengshan Liang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA.,Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Nelson O Gekara
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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44
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Lushnikov A, Hooy R, Sohn J, Krasnoslobodtsev A. Characterization of DNA bound cyclic GMP-AMP synthase using atomic force microscopy imaging. Methods Enzymol 2019; 625:157-166. [PMID: 31455525 DOI: 10.1016/bs.mie.2019.07.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The protocol described herein allows for acquiring topography images of DNA-protein complexes using Atomic Force Microscopy imaging. Since the very beginning of this method, AFM has been an indispensable tool for characterization of biomolecular complexes with exceptional capability of observing single complexes. This method can visualize structural characteristics of DNA-protein assemblies and evaluate differences between individual complexes. Although this protocol is generally applicable to a large number of various proteins complexed with DNA, we use cyclic G/AMP synthase (cGAS) enzyme as a case study for the protocol description.
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Affiliation(s)
- Alexander Lushnikov
- Nanoimaging Core Facility at the University of Nebraska Medical Center, Omaha, NE, United States
| | - Richard Hooy
- Department of Biophysics and Biophysical Chemistry, John Hopkins School of Medicine, Baltimore, MD, United States
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, John Hopkins School of Medicine, Baltimore, MD, United States
| | - Alexey Krasnoslobodtsev
- Nanoimaging Core Facility at the University of Nebraska Medical Center, Omaha, NE, United States; Department of Physics, University of Nebraska Omaha, Omaha, NE, United States.
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45
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Abstract
Cyclic GMP-AMP synthase, cGAS, converts ATP and GTP into a cyclic dinucleotide second messenger, cyclic GMP-AMP or cGAMP, through its enzymatic, nucleotidyl transferase (NTase) activity. Although many methods are available to directly measure cGAMP production, these assays often have high cost of implementation and/or experimental limitations. This chapter details how to implement an alternative approach that is relatively inexpensive, accurate and medium-throughput. The assay measures cGAS NTase activity by quantifying pyrophosphate production, a byproduct of the cGAS reaction. A coupling enzyme, pyrophosphatase, catalyzes the hydrolysis of pyrophosphate into inorganic phosphate, which enables facile detection of cGAS activity through conventional phosphomolybdate-malachite green absorbance methodology. This method is amenable for conventional steady-state kinetic measurements as well as high-throughput compound screening.
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Affiliation(s)
- Richard Hooy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
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46
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Ralph EC, Hall J. An SPR-based analysis of cGAS substrate K D and steady-state K M values. Methods Enzymol 2019; 625:61-76. [PMID: 31455537 DOI: 10.1016/bs.mie.2019.04.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Surface plasmon resonance (SPR) is a standard method for evaluating direct protein-small molecule binding. While studying the catalytic mechanism of cyclic GMP-AMP synthase (cGAS), we developed an SPR-based method to measure steady-state KM values that complements traditional SPR affinity measurements. The method relies on refractive changes to detect protein interaction with substrates and products, and takes advantage of stimulator of type 1 interferon genes (STING) binding to the cGAS product, 2',3'-cGAMP. The specific method described here uses co-immobilization of cGAS and double-stranded DNA through a biotin tag; it should be generally applicable to other proteins and protein complexes.
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Affiliation(s)
- Erik C Ralph
- Worldwide Medicinal Chemistry, Pfizer, Groton, CT, United States.
| | - Justin Hall
- Worldwide Medicinal Chemistry, Pfizer, Groton, CT, United States
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47
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Kumar V. A STING to inflammation and autoimmunity. J Leukoc Biol 2019; 106:171-185. [PMID: 30990921 DOI: 10.1002/jlb.4mir1018-397rr] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 12/19/2022] Open
Abstract
Various intracellular pattern recognition receptors (PRRs) recognize cytosolic pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Cyclic GMP-AMP synthase (cGAS), a cytosolic PRR, recognizes cytosolic nucleic acids including dsDNAs. The recognition of dsDNA by cGAS generates cyclic GMP-AMP (GAMP). The cGAMP is then recognized by STING generating type 1 IFNs and NF-κB-mediated generation of pro-inflammatory cytokines and molecules. Thus, cGAS-STING signaling mediated recognition of cytosolic dsDNA causing the induction of type 1 IFNs plays a crucial role in innate immunity against cytosolic pathogens, PAMPs, and DAMPs. The overactivation of this system may lead to the development of autoinflammation and autoimmune diseases. The article opens with the introduction of different PRRs involved in the intracellular recognition of dsDNA and gives a brief introduction of cGAS-STING signaling. The second section briefly describes cGAS as intracellular PRR required to recognize intracellular nucleic acids (dsDNA and CDNs) and the formation of cGAMP. The cGAMP acts as a second messenger to activate STING- and TANK-binding kinase 1-mediated generation of type 1 IFNs and the activation of NF-κB. The third section of the article describes the role of cGAS-STING signaling in the induction of autoinflammation and various autoimmune diseases. The subsequent fourth section describes both chemical compounds developed and the endogenous negative regulators of cGAS-STING signaling required for its regulation. Therapeutic targeting of cGAS-STING signaling could offer new ways to treat inflammatory and autoimmune diseases.
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Affiliation(s)
- Vijay Kumar
- Children's Health Queensland Clinical Unit, School of Clinical Medicine, Faculty of Medicine, Mater Research, University of Queensland, Brisbane, Queensland, Australia.,School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
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