1
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Bhatt A, Mishra BP, Gu W, Sorbello M, Xu H, Ve T, Kobe B. Structural characterization of TIR-domain signalosomes through a combination of structural biology approaches. IUCRJ 2024; 11:695-707. [PMID: 39190506 PMCID: PMC11364022 DOI: 10.1107/s2052252524007693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 08/05/2024] [Indexed: 08/29/2024]
Abstract
The TIR (Toll/interleukin-1 receptor) domain represents a vital structural element shared by proteins with roles in immunity signalling pathways across phyla (from humans and plants to bacteria). Decades of research have finally led to identifying the key features of the molecular basis of signalling by these domains, including the formation of open-ended (filamentous) assemblies (responsible for the signalling by cooperative assembly formation mechanism, SCAF) and enzymatic activities involving the cleavage of nucleotides. We present a historical perspective of the research that led to this understanding, highlighting the roles that different structural methods played in this process: X-ray crystallography (including serial crystallography), microED (micro-crystal electron diffraction), NMR (nuclear magnetic resonance) spectroscopy and cryo-EM (cryogenic electron microscopy) involving helical reconstruction and single-particle analysis. This perspective emphasizes the complementarity of different structural approaches.
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Affiliation(s)
- Akansha Bhatt
- Institute for GlycomicsGriffith UniversitySouthportQLD4222Australia
- School of Pharmacy and Medical SciencesGriffith UniversitySouthportQLD4222Australia
| | - Biswa P. Mishra
- Institute for GlycomicsGriffith UniversitySouthportQLD4222Australia
| | - Weixi Gu
- School of Chemistry and Molecular BiosciencesUniversity of QueenslandBrisbaneQLD4072Australia
- Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLD4072Australia
- Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQLD4072Australia
| | - Mitchell Sorbello
- School of Chemistry and Molecular BiosciencesUniversity of QueenslandBrisbaneQLD4072Australia
- Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLD4072Australia
- Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQLD4072Australia
| | - Hongyi Xu
- School of Chemistry and Molecular BiosciencesUniversity of QueenslandBrisbaneQLD4072Australia
- Department of Materials and Environmental ChemistryStockholm UniversityStockholmSweden
| | - Thomas Ve
- Institute for GlycomicsGriffith UniversitySouthportQLD4222Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular BiosciencesUniversity of QueenslandBrisbaneQLD4072Australia
- Institute for Molecular BioscienceThe University of QueenslandBrisbaneQLD4072Australia
- Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQLD4072Australia
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2
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Migaud ME, Ziegler M, Baur JA. Regulation of and challenges in targeting NAD + metabolism. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00752-w. [PMID: 39026037 DOI: 10.1038/s41580-024-00752-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2024] [Indexed: 07/20/2024]
Abstract
Nicotinamide adenine dinucleotide, in its oxidized (NAD+) and reduced (NADH) forms, is a reduction-oxidation (redox) co-factor and substrate for signalling enzymes that have essential roles in metabolism. The recognition that NAD+ levels fall in response to stress and can be readily replenished through supplementation has fostered great interest in the potential benefits of increasing or restoring NAD+ levels in humans to prevent or delay diseases and degenerative processes. However, much about the biology of NAD+ and related molecules remains poorly understood. In this Review, we discuss the current knowledge of NAD+ metabolism, including limitations of, assumptions about and unappreciated factors that might influence the success or contribute to risks of NAD+ supplementation. We highlight several ongoing controversies in the field, and discuss the role of the microbiome in modulating the availability of NAD+ precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), the presence of multiple cellular compartments that have distinct pools of NAD+ and NADH, and non-canonical NAD+ and NADH degradation pathways. We conclude that a substantial investment in understanding the fundamental biology of NAD+, its detection and its metabolites in specific cells and cellular compartments is needed to support current translational efforts to safely boost NAD+ levels in humans.
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Affiliation(s)
- Marie E Migaud
- Mitchell Cancer Institute, Department of Pharmacology, Frederick P. Whiddon College of Medicine, University of South Alabama, Mobile, AL, USA.
| | - Mathias Ziegler
- Department of Biomedicine, University of Bergen, Bergen, Norway.
| | - Joseph A Baur
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA.
- Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Philadelphia, PA, USA.
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3
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Hinz FI, Villegas CLM, Roberts JT, Yao H, Gaddam S, Delwig A, Green SA, Fredrickson C, Adrian M, Asuncion RR, Cheung TK, Hayne M, Hackos DH, Rose CM, Richmond D, Hoogenraad CC. Context-Specific Stress Causes Compartmentalized SARM1 Activation and Local Degeneration in Cortical Neurons. J Neurosci 2024; 44:e2424232024. [PMID: 38692735 PMCID: PMC11170950 DOI: 10.1523/jneurosci.2424-23.2024] [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: 12/26/2023] [Revised: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 05/03/2024] Open
Abstract
Sterile alpha and TIR motif containing 1 (SARM1) is an inducible NADase that localizes to mitochondria throughout neurons and senses metabolic changes that occur after injury. Minimal proteomic changes are observed upon either SARM1 depletion or activation, suggesting that SARM1 does not exert broad effects on neuronal protein homeostasis. However, whether SARM1 activation occurs throughout the neuron in response to injury and cell stress remains largely unknown. Using a semiautomated imaging pipeline and a custom-built deep learning scoring algorithm, we studied degeneration in both mixed-sex mouse primary cortical neurons and male human-induced pluripotent stem cell-derived cortical neurons in response to a number of different stressors. We show that SARM1 activation is differentially restricted to specific neuronal compartments depending on the stressor. Cortical neurons undergo SARM1-dependent axon degeneration after mechanical transection, and SARM1 activation is limited to the axonal compartment distal to the injury site. However, global SARM1 activation following vacor treatment causes both cell body and axon degeneration. Context-specific stressors, such as microtubule dysfunction and mitochondrial stress, induce axonal SARM1 activation leading to SARM1-dependent axon degeneration and SARM1-independent cell body death. Our data reveal that compartment-specific SARM1-mediated death signaling is dependent on the type of injury and cellular stressor.
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Affiliation(s)
- Flora I Hinz
- Department of Neuroscience, Genentech, Inc., South San Francisco, California 94080
| | | | - Jasmine T Roberts
- Department of Neuroscience, Genentech, Inc., South San Francisco, California 94080
| | - Heming Yao
- Biological Research | AI Development, Genentech, Inc., South San Francisco, California 94080
| | - Shreya Gaddam
- Biological Research | AI Development, Genentech, Inc., South San Francisco, California 94080
| | - Anton Delwig
- Departments of Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, California 94080
| | - Samantha A Green
- Discovery Chemistry, Genentech, Inc., South San Francisco, California 94080
| | - Craig Fredrickson
- Department of Neuroscience, Genentech, Inc., South San Francisco, California 94080
| | - Max Adrian
- Pathology, Genentech, Inc., South San Francisco, California 94080
| | - Raymond R Asuncion
- Transgenic Technology, Genentech, Inc., South San Francisco, California 94080
| | - Tommy K Cheung
- Microchemistry, Proteomics, and Lipidomics, Genentech, Inc., South San Francisco, California 94080
| | - Margaret Hayne
- Department of Neuroscience, Genentech, Inc., South San Francisco, California 94080
| | - David H Hackos
- Department of Neuroscience, Genentech, Inc., South San Francisco, California 94080
| | - Christopher M Rose
- Microchemistry, Proteomics, and Lipidomics, Genentech, Inc., South San Francisco, California 94080
| | - David Richmond
- Biological Research | AI Development, Genentech, Inc., South San Francisco, California 94080
| | - Casper C Hoogenraad
- Department of Neuroscience, Genentech, Inc., South San Francisco, California 94080
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4
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Cirilli I, Amici A, Gilley J, Coleman MP, Orsomando G. Adaptation of a Commercial NAD + Quantification Kit to Assay the Base-Exchange Activity and Substrate Preferences of SARM1. Molecules 2024; 29:847. [PMID: 38398599 PMCID: PMC10891823 DOI: 10.3390/molecules29040847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Here, we report an adapted protocol using the Promega NAD/NADH-Glo™ Assay kit. The assay normally allows quantification of trace amounts of both oxidized and reduced forms of nicotinamide adenine dinucleotide (NAD) by enzymatic cycling, but we now show that the NAD analog 3-acetylpyridine adenine dinucleotide (AcPyrAD) also acts as a substrate for this enzyme-cycling assay. In fact, AcPyrAD generates amplification signals of a larger amplitude than those obtained with NAD. We exploited this finding to devise and validate a novel method for assaying the base-exchange activity of SARM1 in reactions containing NAD and an excess of the free base 3-acetylpyridine (AcPyr), where the product is AcPyrAD. We then used this assay to study competition between AcPyr and other free bases to rank the preference of SARM1 for different base-exchange substrates, identifying isoquinoline as a highly effect substrate that completely outcompetes even AcPyr. This has significant advantages over traditional HPLC methods for assaying SARM1 base exchange as it is rapid, sensitive, cost-effective, and easily scalable. This could represent a useful tool given current interest in the role of SARM1 base exchange in programmed axon death and related human disorders. It may also be applicable to other multifunctional NAD glycohydrolases (EC 3.2.2.6) that possess similar base-exchange activity.
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Affiliation(s)
- Ilenia Cirilli
- Department of Clinical Sciences (DISCO), Section of Biochemistry, Polytechnic University of Marche, Via Ranieri 67, 60131 Ancona, Italy; (I.C.); (A.A.)
| | - Adolfo Amici
- Department of Clinical Sciences (DISCO), Section of Biochemistry, Polytechnic University of Marche, Via Ranieri 67, 60131 Ancona, Italy; (I.C.); (A.A.)
| | - Jonathan Gilley
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Forvie Site, Robinson Way, Cambridge CB2 0PY, UK; (J.G.); (M.P.C.)
| | - Michael P. Coleman
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Forvie Site, Robinson Way, Cambridge CB2 0PY, UK; (J.G.); (M.P.C.)
| | - Giuseppe Orsomando
- Department of Clinical Sciences (DISCO), Section of Biochemistry, Polytechnic University of Marche, Via Ranieri 67, 60131 Ancona, Italy; (I.C.); (A.A.)
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5
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Tarasiuk O, Molteni L, Malacrida A, Nicolini G. The Role of NMNAT2/SARM1 in Neuropathy Development. BIOLOGY 2024; 13:61. [PMID: 38275737 PMCID: PMC10813049 DOI: 10.3390/biology13010061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 01/27/2024]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) commonly arises as a side effect of diverse cancer chemotherapy treatments. This condition presents symptoms such as numbness, tingling, and altered sensation in patients, often accompanied by neuropathic pain. Pathologically, CIPN is characterized by an intensive "dying-back" axonopathy, starting at the intra-epidermal sensory innervations and advancing retrogradely. The lack of comprehensive understanding regarding its underlying mechanisms explains the absence of effective treatments for CIPN. Recent investigations into axon degeneration mechanisms have pinpointed nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) and sterile alpha and TIR motif-containing 1 protein (SARM1) as pivotal mediators of injury-induced axonal degeneration. In this review, we aim to explore various studies shedding light on the interplay between NMNAT2 and SARM1 proteins and their roles in the progression of CIPN.
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Affiliation(s)
- Olga Tarasiuk
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (L.M.); (A.M.); (G.N.)
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6
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Park SB, Cetinkaya-Fisgin A, Argyriou AA, Höke A, Cavaletti G, Alberti P. Axonal degeneration in chemotherapy-induced peripheral neurotoxicity: clinical and experimental evidence. J Neurol Neurosurg Psychiatry 2023; 94:962-972. [PMID: 37015772 PMCID: PMC10579520 DOI: 10.1136/jnnp-2021-328323] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 02/15/2023] [Indexed: 04/06/2023]
Abstract
Multiple pathological mechanisms are involved in the development of chemotherapy-induced peripheral neurotoxicity (CIPN). Recent work has provided insights into the molecular mechanisms underlying chemotherapy-induced axonal degeneration. This review integrates evidence from preclinical and clinical work on the onset, progression and outcome of axonal degeneration in CIPN. We review likely triggers of axonal degeneration in CIPN and highlight evidence of molecular pathways involved in axonal degeneration and their relevance to CIPN, including SARM1-mediated axon degeneration pathway. We identify potential clinical markers of axonal dysfunction to provide early identification of toxicity as well as present potential treatment strategies to intervene in axonal degeneration pathways. A greater understanding of axonal degeneration processes in CIPN will provide important information regarding the development and progression of axonal dysfunction more broadly and will hopefully assist in the development of successful interventions for CIPN and other neurodegenerative disorders.
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Affiliation(s)
- Susanna B Park
- Brain and Mind Centre, Faculty of Medicine and Health, School of Medical Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Aysel Cetinkaya-Fisgin
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Andreas A Argyriou
- Department of Neurology, "Agios Andreas" State General Hospital of Patras, Patras, Greece
| | - Ahmet Höke
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Guido Cavaletti
- Experimental Neurology Unit and Milan Center for Neuroscience, University of Milano-Bicocca, Monza, Italy
| | - Paola Alberti
- Experimental Neurology Unit and Milan Center for Neuroscience, University of Milano-Bicocca, Monza, Italy
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7
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Icso JD, Barasa L, Thompson PR. SARM1, an Enzyme Involved in Axon Degeneration, Catalyzes Multiple Activities through a Ternary Complex Mechanism. Biochemistry 2023; 62:2065-2078. [PMID: 37307562 DOI: 10.1021/acs.biochem.3c00081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Sterile alpha and toll/interleukin receptor (TIR) motif containing protein 1 (SARM1) is an NAD+ hydrolase and cyclase involved in axonal degeneration. In addition to NAD+ hydrolysis and cyclization, SARM1 catalyzes a base exchange reaction between nicotinic acid (NA) and NADP+ to generate NAADP, which is a potent calcium signaling molecule. Herein, we describe efforts to characterize the hydrolysis, cyclization, and base exchange activities of TIR-1, the Caenorhabditis elegans ortholog of SARM1; TIR-1 also catalyzes NAD(P)+ hydrolysis and/or cyclization and regulates axonal degeneration in worms. We show that the catalytic domain of TIR-1 undergoes a liquid-to-solid phase transition that regulates not only the hydrolysis and cyclization reactions but also the base exchange reaction. We define the substrate specificities of the reactions, demonstrate that cyclization and base exchange reactions occur within the same pH range, and establish that TIR-1 uses a ternary complex mechanism. Overall, our findings will aid drug discovery efforts and provide insight into the mechanism of recently described inhibitors.
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Affiliation(s)
- Janneke D Icso
- Program in Chemical Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medial School, Worcester, Massachusetts 01605, United States
| | - Leonard Barasa
- Program in Chemical Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medial School, Worcester, Massachusetts 01605, United States
| | - Paul R Thompson
- Program in Chemical Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medial School, Worcester, Massachusetts 01605, United States
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8
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Huang K, Zhu WJ, Li WH, Lee HC, Zhao YJ, Lee CS. Base-Exchange Enabling the Visualization of SARM1 Activities in Sciatic Nerve-Injured Mice. ACS Sens 2023; 8:767-773. [PMID: 36689294 PMCID: PMC9972468 DOI: 10.1021/acssensors.2c02317] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Enzymes are important in homeostasis in living organisms. Since abnormal enzyme activities are highly associated with many human diseases, detection of in vivo activities of a specific enzyme is important to study the pathology of the related diseases. In this work, we have designed and synthesized a series of new small-molecule-activatable fluorescent probes for the imaging of Sterile Alpha and TIR Motif-containing 1 (SARM1) activities based on its transglycosidase activities (base-exchange reactions of NAD+). Probe 1a was found to undergo base-exchange reactions with NAD+ in the presence of activated SARM1 but not CD38 nor NADase and formed a highly emissive product AD-1a [about a 100-fold fluorescence enhancement in 20 min with a 150 nm (5665 cm-1) Stokes shift and a 100 nm (3812 cm-1) red shift]. This probe exhibited a higher reactivity and sensitivity than those commonly used for SARM1 imaging. The utilities of 1a have also been demonstrated in live-cell imaging and detection of in vivo activities of SARM1 in a sciatic nerve injury mouse model.
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Affiliation(s)
- Ke Huang
- Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Kowloon, Hong Kong SAR 999077, China
| | - Wen Jie Zhu
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, Lishui Road, Shenzhen 518055, China
| | - Wan Hua Li
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, Lishui Road, Shenzhen 518055, China.,Ciechanover Institute of Precision and Regenerative Medicine, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong Shenzhen, Shenzhen 518172, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Hon Cheung Lee
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, Lishui Road, Shenzhen 518055, China
| | - Yong Juan Zhao
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, Lishui Road, Shenzhen 518055, China.,Ciechanover Institute of Precision and Regenerative Medicine, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong Shenzhen, Shenzhen 518172, China.,Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen 518055, China
| | - Chi-Sing Lee
- Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Kowloon, Hong Kong SAR 999077, China
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9
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Abstract
The discovery of NAADP-evoked Ca2+ release in sea urchin eggs and then as a ubiquitous Ca2+ mobilizing messenger has introduced several novel paradigms to our understanding of Ca2+ signalling, not least in providing a link between cell stimulation and Ca2+ release from lysosomes and other acidic Ca2+ storage organelles. In addition, the hallmark concentration-response relationship of NAADP-mediated Ca2+ release, shaped by striking activation/desensitization mechanisms, influences its actions as an intracellular messenger. There has been recent progress in our understanding of the molecular mechanisms underlying NAADP-evoked Ca2+ release, such as the identification of the endo-lysosomal two-pore channel family of cation channels (TPCs) as their principal target and the identity of NAADP-binding proteins that complex with them. The NAADP/TPC signalling axis has gained recent prominence in pathophysiology for their roles in such disease processes as neurodegeneration, tumorigenesis and cellular viral entry.
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Affiliation(s)
- Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK.
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Lora L Martucci
- Department of Pharmacology, University of Oxford, Oxford, UK
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10
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Khazma T, Golan-Vaishenker Y, Guez-Haddad J, Grossman A, Sain R, Weitman M, Plotnikov A, Zalk R, Yaron A, Hons M, Opatowsky Y. A duplex structure of SARM1 octamers stabilized by a new inhibitor. Cell Mol Life Sci 2022; 80:16. [PMID: 36564647 PMCID: PMC11072711 DOI: 10.1007/s00018-022-04641-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 11/16/2022] [Accepted: 11/19/2022] [Indexed: 12/25/2022]
Abstract
In recent years, there has been growing interest in SARM1 as a potential breakthrough drug target for treating various pathologies of axon degeneration. SARM1-mediated axon degeneration relies on its TIR domain NADase activity, but recent structural data suggest that the non-catalytic ARM domain could also serve as a pharmacological site as it has an allosteric inhibitory function. Here, we screened for synthetic small molecules that inhibit SARM1, and tested a selected set of these compounds in a DRG axon degeneration assay. Using cryo-EM, we found that one of the newly discovered inhibitors, a calmidazolium designated TK106, not only stabilizes the previously reported inhibited conformation of the octamer, but also a meta-stable structure: a duplex of octamers (16 protomers), which we have now determined to 4.0 Å resolution. In the duplex, each ARM domain protomer is engaged in lateral interactions with neighboring protomers, and is further stabilized by contralateral contacts with the opposing octamer ring. Mutagenesis of the duplex contact sites leads to a moderate increase in SARM1 activation in cultured cells. Based on our data we propose that the duplex assembly constitutes an additional auto-inhibition mechanism that tightly prevents pre-mature activation and axon degeneration.
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Affiliation(s)
- Tami Khazma
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | | | - Julia Guez-Haddad
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Atira Grossman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Radhika Sain
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Michal Weitman
- Department of Chemistry, Bar-Ilan University, Ramat Gan, Israel
| | - Alexander Plotnikov
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Ran Zalk
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
- Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Avraham Yaron
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Michael Hons
- European Molecular Biology Laboratory, Grenoble, France.
| | - Yarden Opatowsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
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11
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A conformation-specific nanobody targeting the nicotinamide mononucleotide-activated state of SARM1. Nat Commun 2022; 13:7898. [PMID: 36550129 PMCID: PMC9780360 DOI: 10.1038/s41467-022-35581-y] [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: 04/14/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
Sterile alpha (SAM) and Toll/interleukin-1 receptor (TIR) motif containing 1 (SARM1) is an autoinhibitory NAD-consuming enzyme that is activated by the accumulation of nicotinamide mononucleotide (NMN) during axonal injury. Its activation mechanism is not fully understood. Here, we generate a nanobody, Nb-C6, that specifically recognizes NMN-activated SARM1. Nb-C6 stains only the activated SARM1 in cells stimulated with CZ-48, a permeant mimetic of NMN, and partially activates SARM1 in vitro and in cells. Cryo-EM of NMN/SARM1/Nb-C6 complex shows an octameric structure with ARM domains bending significantly inward and swinging out together with TIR domains. Nb-C6 binds to SAM domain of the activated SARM1 and stabilized its ARM domain. Mass spectrometry analyses indicate that the activated SARM1 in solution is highly dynamic and that the neighboring TIRs form transient dimers via the surface close to one BB loop. We show that Nb-C6 is a valuable tool for studies of SARM1 activation.
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12
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Bratkowski M, Burdett TC, Danao J, Wang X, Mathur P, Gu W, Beckstead JA, Talreja S, Yang YS, Danko G, Park JH, Walton M, Brown SP, Tegley CM, Joseph PRB, Reynolds CH, Sambashivan S. Uncompetitive, adduct-forming SARM1 inhibitors are neuroprotective in preclinical models of nerve injury and disease. Neuron 2022; 110:3711-3726.e16. [PMID: 36087583 DOI: 10.1016/j.neuron.2022.08.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/06/2022] [Accepted: 08/10/2022] [Indexed: 12/15/2022]
Abstract
Axon degeneration is an early pathological event in many neurological diseases. The identification of the nicotinamide adenine dinucleotide (NAD) hydrolase SARM1 as a central metabolic sensor and axon executioner presents an exciting opportunity to develop novel neuroprotective therapies that can prevent or halt the degenerative process, yet limited progress has been made on advancing efficacious inhibitors. We describe a class of NAD-dependent active-site SARM1 inhibitors that function by intercepting NAD hydrolysis and undergoing covalent conjugation with the reaction product adenosine diphosphate ribose (ADPR). The resulting small-molecule ADPR adducts are highly potent and confer compelling neuroprotection in preclinical models of neurological injury and disease, validating this mode of inhibition as a viable therapeutic strategy. Additionally, we show that the most potent inhibitor of CD38, a related NAD hydrolase, also functions by the same mechanism, further underscoring the broader applicability of this mechanism in developing therapies against this class of enzymes.
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Affiliation(s)
| | - Thomas C Burdett
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Jean Danao
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Xidao Wang
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Prakhyat Mathur
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Weijing Gu
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | | | - Santosh Talreja
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Yu-San Yang
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Gregory Danko
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Jae Hong Park
- Biology Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Mary Walton
- Chemistry Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | - Sean P Brown
- Chemistry Department, Nura Bio Inc., South San Francisco, CA 94080, USA
| | | | - Prem Raj B Joseph
- WuXi AppTec, Research Services Division, 6 Cedarbrook Drive, Cranbury, NJ 08512, USA
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13
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Wang S, Song M, Yong H, Zhang C, Kang K, Liu Z, Yang Y, Huang Z, Wang S, Ge H, Zhao X, Song F. Mitochondrial Localization of SARM1 in Acrylamide Intoxication Induces Mitophagy and Limits Neuropathy. Mol Neurobiol 2022; 59:7337-7353. [PMID: 36171479 DOI: 10.1007/s12035-022-03050-8] [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: 03/14/2022] [Accepted: 09/14/2022] [Indexed: 10/14/2022]
Abstract
Sterile α and toll/interleukin 1 receptor motif-containing protein 1 (SARM1) is the defining molecule and central executioner of programmed axon death, also known as Wallerian degeneration. SARM1 has a mitochondrial targeting sequence, and it can bind to and stabilize PTEN-induced putative kinase 1 (PINK1) for mitophagy induction, but the deletion of the mitochondrial localization sequence is found to disrupt the mitochondrial localization of SARM1 in neurons without altering its ability to promote axon degeneration after axotomy. The biological significance of SARM1 mitochondrial localization remains elusive. In this study, we observed that the pro-degeneration factor, SARM1, was upregulated in acrylamide (ACR) neuropathy, a slow, Wallerian-like, programmed axonal death process. The upregulated SARM1 accumulated on mitochondria, interfered with mitochondrial dynamics, and activated PINK1-mediated mitophagy. Importantly, rapamycin (RAPA) intervention eliminated mitochondrial accumulation of SARM1 and partly attenuated ACR neuropathy. Thus, mitochondrial localization of SARM1 may contribute to its clearance through the SARM1-PINK1 mitophagy pathway, which inhibits axonal degeneration through a negative feedback loop. The mitochondrial localization of SARM1 complements the coordinated activity of the pro-survival factor, nicotinamide mononucleotide adenyltransferase 2 (NMNAT2), and SARM1 and is part of the self-limiting molecular mechanisms underpinning programmed axon death in ACR neuropathy. Mitophagy clearance of SARM1 is complementary to the coordinated activity of NMNAT2 and SARM1 in ACR neuropathy.
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Affiliation(s)
- Shuai Wang
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Mingxue Song
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Hui Yong
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Cuiqin Zhang
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China.,School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Kang Kang
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Zhidan Liu
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Yiyu Yang
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Zhengcheng Huang
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Shu'e Wang
- School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Haotong Ge
- School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Xiulan Zhao
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China.,School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Fuyong Song
- Department of Toxicology and Nutrition, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China.
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14
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Feldman HC, Merlini E, Guijas C, DeMeester KE, Njomen E, Kozina EM, Yokoyama M, Vinogradova E, Reardon HT, Melillo B, Schreiber SL, Loreto A, Blankman JL, Cravatt BF. Selective inhibitors of SARM1 targeting an allosteric cysteine in the autoregulatory ARM domain. Proc Natl Acad Sci U S A 2022; 119:e2208457119. [PMID: 35994671 PMCID: PMC9436332 DOI: 10.1073/pnas.2208457119] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/25/2022] [Indexed: 12/23/2022] Open
Abstract
The nicotinamide adenine dinucleotide hydrolase (NADase) sterile alpha toll/interleukin receptor motif containing-1 (SARM1) acts as a central executioner of programmed axon death and is a possible therapeutic target for neurodegenerative disorders. While orthosteric inhibitors of SARM1 have been described, this multidomain enzyme is also subject to intricate forms of autoregulation, suggesting the potential for allosteric modes of inhibition. Previous studies have identified multiple cysteine residues that support SARM1 activation and catalysis, but which of these cysteines, if any, might be selectively targetable by electrophilic small molecules remains unknown. Here, we describe the chemical proteomic discovery of a series of tryptoline acrylamides that site-specifically and stereoselectively modify cysteine-311 (C311) in the noncatalytic, autoregulatory armadillo repeat (ARM) domain of SARM1. These covalent compounds inhibit the NADase activity of WT-SARM1, but not C311A or C311S SARM1 mutants, show a high degree of proteome-wide selectivity for SARM1_C311 and stereoselectively block vincristine- and vacor-induced neurite degeneration in primary rodent dorsal root ganglion neurons. Our findings describe selective, covalent inhibitors of SARM1 targeting an allosteric cysteine, pointing to a potentially attractive therapeutic strategy for axon degeneration-dependent forms of neurological disease.
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Affiliation(s)
| | - Elisa Merlini
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, United Kingdom
| | - Carlos Guijas
- Lundbeck La Jolla Research Center Inc, San Diego, CA 92121
| | | | - Evert Njomen
- Department of Chemistry, Scripps Research, La Jolla, CA 92037
| | - Ellen M Kozina
- Lundbeck La Jolla Research Center Inc, San Diego, CA 92121
| | - Minoru Yokoyama
- Department of Chemistry, Scripps Research, La Jolla, CA 92037
| | | | | | - Bruno Melillo
- Department of Chemistry, Scripps Research, La Jolla, CA 92037
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02138
| | - Stuart L Schreiber
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA 02138
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138
| | - Andrea Loreto
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, United Kingdom
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15
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Paracrine ADP Ribosyl Cyclase-Mediated Regulation of Biological Processes. Cells 2022; 11:cells11172637. [PMID: 36078044 PMCID: PMC9454491 DOI: 10.3390/cells11172637] [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: 07/20/2022] [Revised: 08/12/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
ADP-ribosyl cyclases (ADPRCs) catalyze the synthesis of the Ca2+-active second messengers Cyclic ADP-ribose (cADPR) and ADP-ribose (ADPR) from NAD+ as well as nicotinic acid adenine dinucleotide phosphate (NAADP+) from NADP+. The best characterized ADPRC in mammals is CD38, a single-pass transmembrane protein with two opposite membrane orientations. The first identified form, type II CD38, is a glycosylated ectoenzyme, while type III CD38 has its active site in the cytosol. The ectoenzymatic nature of type II CD38 raised long ago the question of a topological paradox concerning the access of the intracellular NAD+ substrate to the extracellular active site and of extracellular cADPR product to its intracellular receptors, ryanodine (RyR) channels. Two different transporters, equilibrative connexin 43 (Cx43) hemichannels for NAD+ and concentrative nucleoside transporters (CNTs) for cADPR, proved to mediate cell-autonomous trafficking of both nucleotides. Here, we discussed how type II CD38, Cx43 and CNTs also play a role in mediating several paracrine processes where an ADPRC+ cell supplies a neighboring CNT-and RyR-expressing cell with cADPR. Recently, type II CD38 was shown to start an ectoenzymatic sequence of reactions from NAD+/ADPR to the strong immunosuppressant adenosine; this paracrine effect represents a major mechanism of acquired resistance of several tumors to immune checkpoint therapy.
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16
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Shi Y, Kerry PS, Nanson JD, Bosanac T, Sasaki Y, Krauss R, Saikot FK, Adams SE, Mosaiab T, Masic V, Mao X, Rose F, Vasquez E, Furrer M, Cunnea K, Brearley A, Gu W, Luo Z, Brillault L, Landsberg MJ, DiAntonio A, Kobe B, Milbrandt J, Hughes RO, Ve T. Structural basis of SARM1 activation, substrate recognition, and inhibition by small molecules. Mol Cell 2022; 82:1643-1659.e10. [PMID: 35334231 PMCID: PMC9188649 DOI: 10.1016/j.molcel.2022.03.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 01/11/2022] [Accepted: 03/01/2022] [Indexed: 01/04/2023]
Abstract
The NADase SARM1 (sterile alpha and TIR motif containing 1) is a key executioner of axon degeneration and a therapeutic target for several neurodegenerative conditions. We show that a potent SARM1 inhibitor undergoes base exchange with the nicotinamide moiety of nicotinamide adenine dinucleotide (NAD+) to produce the bona fide inhibitor 1AD. We report structures of SARM1 in complex with 1AD, NAD+ mimetics and the allosteric activator nicotinamide mononucleotide (NMN). NMN binding triggers reorientation of the armadillo repeat (ARM) domains, which disrupts ARM:TIR interactions and leads to formation of a two-stranded TIR domain assembly. The active site spans two molecules in these assemblies, explaining the requirement of TIR domain self-association for NADase activity and axon degeneration. Our results reveal the mechanisms of SARM1 activation and substrate binding, providing rational avenues for the design of new therapeutics targeting SARM1.
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Affiliation(s)
- Yun Shi
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Philip S Kerry
- Evotec (UK) Ltd., 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, UK
| | - Jeffrey D Nanson
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, QLD 4072, Australia
| | - Todd Bosanac
- Disarm Therapeutics, a wholly-owned subsidiary of Eli Lilly & Co., Cambridge, MA, USA
| | - Yo Sasaki
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Genetics, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA
| | - Raul Krauss
- Disarm Therapeutics, a wholly-owned subsidiary of Eli Lilly & Co., Cambridge, MA, USA
| | - Forhad K Saikot
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, QLD 4072, Australia
| | - Sarah E Adams
- Evotec (UK) Ltd., 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, UK
| | - Tamim Mosaiab
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Veronika Masic
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Xianrong Mao
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Genetics, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA
| | - Faith Rose
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Eduardo Vasquez
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Marieke Furrer
- Evotec SE, Manfred Eigen Campus, Essener Bogen 7, 22419 Hamburg, Germany
| | - Katie Cunnea
- Evotec (UK) Ltd., 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, UK
| | - Andrew Brearley
- Evotec (UK) Ltd., 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, UK
| | - Weixi Gu
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, QLD 4072, Australia
| | - Zhenyao Luo
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, QLD 4072, Australia
| | - Lou Brillault
- Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Australia
| | - Michael J Landsberg
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, QLD 4072, Australia
| | - Aaron DiAntonio
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Developmental Biology, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, QLD 4072, Australia
| | - Jeffrey Milbrandt
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Genetics, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA
| | - Robert O Hughes
- Disarm Therapeutics, a wholly-owned subsidiary of Eli Lilly & Co., Cambridge, MA, USA.
| | - Thomas Ve
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia.
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17
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Angeletti C, Amici A, Gilley J, Loreto A, Trapanotto AG, Antoniou C, Merlini E, Coleman MP, Orsomando G. SARM1 is a multi-functional NAD(P)ase with prominent base exchange activity, all regulated bymultiple physiologically relevant NAD metabolites. iScience 2022; 25:103812. [PMID: 35198877 PMCID: PMC8844822 DOI: 10.1016/j.isci.2022.103812] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 12/13/2021] [Accepted: 01/20/2022] [Indexed: 12/11/2022] Open
Abstract
SARM1 is an NAD(P) glycohydrolase and TLR adapter with an essential, prodegenerative role in programmed axon death (Wallerian degeneration). Like other NAD(P)ases, it catalyzes multiple reactions that need to be fully investigated. Here, we compare these multiple activities for recombinant human SARM1, human CD38, and Aplysia californica ADP ribosyl cyclase. SARM1 has the highest transglycosidation (base exchange) activity at neutral pH and with some bases this dominates NAD(P) hydrolysis and cyclization. All SARM1 activities, including base exchange at neutral pH, are activated by an increased NMN:NAD ratio, at physiological levels of both metabolites. SARM1 base exchange occurs also in DRG neurons and is thus a very likely physiological source of calcium-mobilizing agent NaADP. Finally, we identify regulation by free pyridines, NADP, and nicotinic acid riboside (NaR) on SARM1, all of therapeutic interest. Understanding which specific SARM1 function(s) is responsible for axon degeneration is essential for its targeting in disease. Base exchange is a prominent, and sometimes completely dominant, SARM1 activity Physiologically relevant NMN:NAD ratios may regulate all of SARM1's multiple activities Physiological NADP may inhibit SARM1 more potently than NAD and via a distinct site NaR and VR both selectively inhibit SARM1 and are thus possible effectors or drug leads
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18
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Bloom AJ, Mao X, Strickland A, Sasaki Y, Milbrandt J, DiAntonio A. Constitutively active SARM1 variants that induce neuropathy are enriched in ALS patients. Mol Neurodegener 2022; 17:1. [PMID: 34991663 PMCID: PMC8739729 DOI: 10.1186/s13024-021-00511-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/17/2021] [Indexed: 03/31/2023] Open
Abstract
Background In response to injury, neurons activate a program of organized axon self-destruction initiated by the NAD+ hydrolase, SARM1. In healthy neurons SARM1 is autoinhibited, but single amino acid changes can abolish autoinhibition leading to constitutively active SARM1 enzymes that promote degeneration when expressed in cultured neurons. Methods To investigate whether naturally occurring human variants might disrupt SARM1 autoinhibition and potentially contribute to risk for neurodegenerative disease, we assayed the enzymatic activity of all 42 rare SARM1 alleles identified among 8507 amyotrophic lateral sclerosis (ALS) patients and 9671 controls. We then intrathecally injected mice with virus expressing SARM1 constructs to test the capacity of an ALS-associated constitutively active SARM1 variant to promote neurodegeneration in vivo. Results Twelve out of 42 SARM1 missense variants or small in-frame deletions assayed exhibit constitutive NADase activity, including more than half of those that are unique to the ALS patients or that occur in multiple patients. There is a > 5-fold enrichment of constitutively active variants among patients compared to controls. Expression of constitutively active ALS-associated SARM1 alleles in cultured dorsal root ganglion (DRG) neurons is pro-degenerative and cytotoxic. Intrathecal injection of an AAV expressing the common SARM1 reference allele is innocuous to mice, but a construct harboring SARM1V184G, the constitutively active variant found most frequently among the ALS patients, causes axon loss, motor dysfunction, and sustained neuroinflammation. Conclusions These results implicate rare hypermorphic SARM1 alleles as candidate genetic risk factors for ALS and other neurodegenerative conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s13024-021-00511-x.
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Affiliation(s)
- A Joseph Bloom
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Genetics, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA.
| | - Xianrong Mao
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Genetics, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA
| | - Amy Strickland
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Genetics, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA
| | - Yo Sasaki
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Genetics, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA
| | - Jeffrey Milbrandt
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Genetics, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA.
| | - Aaron DiAntonio
- Needleman Center for Neurometabolism and Axonal Therapeutics and Department of Developmental Biology, Washington University School of Medicine in Saint Louis, St. Louis, MO, USA.
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19
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Gorbunova V, Buschbeck M, Cambronne XA, Chellappa K, Corda D, Du J, Freichel M, Gigas J, Green AE, Gu F, Guberovic I, Jayabalan A, Khansahib I, Mukherjee S, Seluanov A, Simon MA, Sverkeli LJ, Kory N, Levine DC, Matic I, Nikiforov A, Rack JG, Imai SI, Sinclair DA, Toiber D, Zhao Y, Mostoslavsky R, Kraus L, Guse AH. The 2021 FASEB science research conference on NAD metabolism and signaling. Aging (Albany NY) 2021. [PMCID: PMC8714140 DOI: 10.18632/aging.203766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Vera Gorbunova
- Departments of Biology and Medicine, University of Rochester, Rochester, NY 14627, USA
| | - Marcus Buschbeck
- Cancer and Leukaemia Epigenetics and Biology Program, Josep Carreras Leukaemia Research Institute (IJC), Campus ICO-GTP-UAB, Badalona, Catalonia 08916, Spain
- Program for Predictive and Personalized Medicine of Cancer, Germans Trias i Pujol Research Institute (PMPPC-IGTP), Badalona, Catalonia 08916, Spain
| | - Xiaolu A. Cambronne
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78705, USA
| | - Karthikeyani Chellappa
- Department of Physiology and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, PA 19104, USA
| | - Daniela Corda
- Department of Biomedical Sciences, National Research Council, Rome 00185, Italy
| | - Juan Du
- Department of Structural Biology, Van Andel Institute, Grand Rapids, MI 49503, USA
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Baden-Württemberg 69117, Germany
| | - Jonathan Gigas
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Alexander E. Green
- Ottawa Institute of Systems Biology, Interdisciplinary School of Health Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Éric Poulin Centre for Neuromuscular Disease, Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Feng Gu
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg 20246, Germany
| | - Iva Guberovic
- Cancer and Leukaemia Epigenetics and Biology Program, Josep Carreras Leukaemia Research Institute (IJC), Campus ICO-GTP-UAB, Badalona, Catalonia 08916, Spain
| | - Aravinthkumar Jayabalan
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Imrankhan Khansahib
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg 20246, Germany
| | - Sarmistha Mukherjee
- Department of Physiology and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, PA 19104, USA
| | - Andrei Seluanov
- Departments of Biology and Medicine, University of Rochester, Rochester, NY 14627, USA
| | - Matthew A. Simon
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Lars J. Sverkeli
- Department of Biological Sciences, University of Bergen, Bergen, Vestland 5007, Norway
| | - Nora Kory
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA 02115, USA
| | - Daniel C. Levine
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Ivan Matic
- Max Planck Institute for Biology of Ageing, Cologne, Nordrhein-Westfalen 50931, Germany
| | - Andrey Nikiforov
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg 199178, Russia
| | - Johannes G.M. Rack
- Sir William Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire OX1 3RE, UK
| | - Shin-Ichiro Imai
- Department of Developmental Biology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Gerontology, Laboratory of Molecular Life Science, Institute of Biomedical Research and Innovation, Kobe, Hyogo 650-0047, Japan
| | - David A. Sinclair
- Genetics Department, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Debra Toiber
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Yongjuan Zhao
- Ciechanover Institute of Precision and Regenerative Medicine, School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Raul Mostoslavsky
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA 02115, USA
- The Broad Institute of Harvard and MIT, Cambridge, MA 02114, USA
| | - Lee Kraus
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Andreas H. Guse
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg 20246, Germany
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20
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Mitochondrial dysfunction as a trigger of programmed axon death. Trends Neurosci 2021; 45:53-63. [PMID: 34852932 DOI: 10.1016/j.tins.2021.10.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 10/05/2021] [Accepted: 10/29/2021] [Indexed: 12/31/2022]
Abstract
Mitochondrial failure has long been associated with programmed axon death (Wallerian degeneration, WD), a widespread and potentially preventable mechanism of axon degeneration. While early findings in axotomised axons indicated that mitochondria are involved during the execution steps of this pathway, recent studies suggest that in addition, mitochondrial dysfunction can initiate programmed axon death without physical injury. As mitochondrial dysfunction is associated with disorders involving early axon loss, including Parkinson's disease, peripheral neuropathies, and multiple sclerosis, the findings that programmed axon death is activated by mitochondrial impairment could indicate the involvement of druggable mechanisms whose disruption may protect axons in such diseases. Here, we review the latest developments linking mitochondrial dysfunction to programmed axon death and discuss their implications for injury and disease.
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21
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The calcium signaling enzyme CD38 - a paradigm for membrane topology defining distinct protein functions. Cell Calcium 2021; 101:102514. [PMID: 34896700 DOI: 10.1016/j.ceca.2021.102514] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/28/2021] [Accepted: 11/29/2021] [Indexed: 12/27/2022]
Abstract
CD38 is a single-pass transmembrane enzyme catalyzing the synthesis of two nucleotide second messengers, cyclic ADP-ribose (cADPR) from NAD and nicotinic acid adenine dinucleotide phosphate (NAADP) from NADP. The former mediates the mobilization of the endoplasmic Ca2+-stores in response to a wide range of stimuli, while NAADP targets the endo-lysosomal stores. CD38 not only possesses multiple enzymatic activities, it also exists in two opposite membrane orientations. Type III CD38 has the catalytic domain facing the cytosol and is responsible for producing cellular cADPR. The type II CD38 has an opposite orientation and is serving as a surface receptor mediating extracellular functions such as cell adhesion and lymphocyte activation. Its ecto-NADase activity also contributes to the recycling of external NAD released by apoptosis. Endocytosis can deliver surface type II CD38 to endo-lysosomes, which acidic environment favors the production of NAADP. This article reviews the rationale and evidence that have led to CD38 as a paradigm for membrane topology defining distinct functions of proteins. Also described is the recent discovery of a hitherto unknown cADPR-synthesizing enzyme, SARM1, ushering in a new frontier in cADPR-mediated Ca2+-signaling.
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22
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Doran CG, Sugisawa R, Carty M, Roche F, Fergus C, Hokamp K, Kelly VP, Bowie AG. CRISPR/Cas9-mediated SARM1 knockout and epitope-tagged mice reveal that SARM1 does not regulate nuclear transcription, but is expressed in macrophages. J Biol Chem 2021; 297:101417. [PMID: 34793837 DOI: 10.1016/j.jbc.2021.101417] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 10/19/2022] Open
Abstract
SARM1 is a toll/interleukin-1 receptor -domain containing protein, with roles proposed in both innate immunity and neuronal degeneration. Murine SARM1 has been reported to regulate the transcription of chemokines in both neurons and macrophages; however, the extent to which SARM1 contributes to transcription regulation remains to be fully understood. Here, we identify differential gene expression in bone-marrow-derived macrophages (BMDMs) from C57BL/6 congenic 129 ES cell-derived Sarm1-/- mice compared with wild type (WT). However, we found that passenger genes, which are derived from the 129 donor strain of mice that flank the Sarm1 locus, confound interpretation of the results, since many of the identified differentially regulated genes come from this region. To re-examine the transcriptional role of SARM1 in the absence of passenger genes, here we generated three Sarm1-/- mice using CRISPR/Cas9. Treatment of neurons from these mice with vincristine, a chemotherapeutic drug causing axonal degeneration, confirmed SARM1's function in that process; however, these mice also showed that lack of SARM1 has no impact on transcription of genes previously shown to be affected such as chemokines. To gain further insight into SARM1 function, we generated an epitope-tagged SARM1 mouse. In these mice, we observed high SARM1 protein expression in the brain and brainstem and lower but detectable levels in macrophages. Overall, the generation of these SARM1 knockout and epitope-tagged mice has clarified that SARM1 is expressed in mouse macrophages yet has no general role in macrophage transcriptional regulation and has provided important new models to further explore SARM1 function.
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Affiliation(s)
- Ciara G Doran
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Ryoichi Sugisawa
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Michael Carty
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Fiona Roche
- School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Claire Fergus
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Karsten Hokamp
- School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Vincent P Kelly
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Andrew G Bowie
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
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23
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Sasaki Y, Zhu J, Shi Y, Gu W, Kobe B, Ve T, DiAntonio A, Milbrandt J. Nicotinic acid mononucleotide is an allosteric SARM1 inhibitor promoting axonal protection. Exp Neurol 2021; 345:113842. [PMID: 34403688 PMCID: PMC8571713 DOI: 10.1016/j.expneurol.2021.113842] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/09/2021] [Accepted: 08/12/2021] [Indexed: 12/31/2022]
Abstract
SARM1 is an inducible NAD+ hydrolase that is the central executioner of pathological axon loss. Recently, we elucidated the molecular mechanism of SARM1 activation, demonstrating that SARM1 is a metabolic sensor regulated by the levels of NAD+ and its precursor, nicotinamide mononucleotide (NMN), via their competitive binding to an allosteric site within the SARM1 N-terminal ARM domain. In healthy neurons with abundant NAD+, binding of NAD+ blocks access of NMN to this allosteric site. However, with injury or disease the levels of the NAD+ biosynthetic enzyme NMNAT2 drop, increasing the NMN/ NAD+ ratio and thereby promoting NMN binding to the SARM1 allosteric site, which in turn induces a conformational change activating the SARM1 NAD+ hydrolase. Hence, NAD+ metabolites both regulate the activation of SARM1 and, in turn, are regulated by the SARM1 NAD+ hydrolase. This dual upstream and downstream role for NAD+ metabolites in SARM1 function has hindered mechanistic understanding of axoprotective mechanisms that manipulate the NAD+ metabolome. Here we reevaluate two methods that potently block axon degeneration via modulation of NAD+ related metabolites, 1) the administration of the NMN biosynthesis inhibitor FK866 in conjunction with the NAD+ precursor nicotinic acid riboside (NaR) and 2) the neuronal expression of the bacterial enzyme NMN deamidase. We find that these approaches not only lead to a decrease in the levels of the SARM1 activator NMN, but also an increase in the levels of the NAD+ precursor nicotinic acid mononucleotide (NaMN). We show that NaMN inhibits SARM1 activation, and demonstrate that this NaMN-mediated inhibition is important for the long-term axon protection induced by these treatments. Analysis of the NaMN-ARM domain co-crystal structure shows that NaMN competes with NMN for binding to the SARM1 allosteric site and promotes the open, autoinhibited configuration of SARM1 ARM domain. Together, these results demonstrate that the SARM1 allosteric pocket can bind a diverse set of metabolites including NMN, NAD+, and NaMN to monitor cellular NAD+ homeostasis and regulate SARM1 NAD+ hydrolase activity. The relative promiscuity of the allosteric site may enable the development of potent pharmacological inhibitors of SARM1 activation for the treatment of neurodegenerative disorders.
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Affiliation(s)
- Yo Sasaki
- Washington University School of Medicine in Saint Louis, Department of Genetics, St. Louis, MO, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, USA.
| | - Jian Zhu
- Washington University School of Medicine in Saint Louis, Department of Genetics, St. Louis, MO, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, USA
| | - Yun Shi
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Weixi Gu
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, QLD 4072, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, QLD 4072, Australia
| | - Thomas Ve
- Institute for Glycomics, Griffith University, Southport, QLD 4222, Australia
| | - Aaron DiAntonio
- Washington University School of Medicine in Saint Louis, Department of Developmental Biology, St. Louis, MO, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, USA
| | - Jeffrey Milbrandt
- Washington University School of Medicine in Saint Louis, Department of Genetics, St. Louis, MO, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, USA
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24
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Wu T, Zhu J, Strickland A, Ko KW, Sasaki Y, Dingwall CB, Yamada Y, Figley MD, Mao X, Neiner A, Bloom AJ, DiAntonio A, Milbrandt J. Neurotoxins subvert the allosteric activation mechanism of SARM1 to induce neuronal loss. Cell Rep 2021; 37:109872. [PMID: 34686345 PMCID: PMC8638332 DOI: 10.1016/j.celrep.2021.109872] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/06/2021] [Accepted: 09/29/2021] [Indexed: 10/20/2022] Open
Abstract
SARM1 is an inducible TIR-domain NAD+ hydrolase that mediates pathological axon degeneration. SARM1 is activated by an increased ratio of NMN to NAD+, which competes for binding to an allosteric activating site. When NMN binds, the TIR domain is released from autoinhibition, activating its NAD+ hydrolase activity. The discovery of this allosteric activating site led us to hypothesize that other NAD+-related metabolites might activate SARM1. Here, we show the nicotinamide analog 3-acetylpyridine (3-AP), first identified as a neurotoxin in the 1940s, is converted to 3-APMN, which activates SARM1 and induces SARM1-dependent NAD+ depletion, axon degeneration, and neuronal death. In mice, systemic treatment with 3-AP causes rapid SARM1-dependent death, while local application to the peripheral nerve induces SARM1-dependent axon degeneration. We identify 2-aminopyridine as another SARM1-dependent neurotoxin. These findings identify SARM1 as a candidate mediator of environmental neurotoxicity and suggest that SARM1 agonists could be developed into selective agents for neurolytic therapy.
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Affiliation(s)
- Tong Wu
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jian Zhu
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine in Saint Louis, St. Louis, MO 63114, USA
| | - Amy Strickland
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA
| | - Kwang Woo Ko
- Department of Developmental Biology, Washington University Medical School, St. Louis, MO 63110, USA
| | - Yo Sasaki
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA
| | - Caitlin B Dingwall
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA
| | - Yurie Yamada
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA
| | - Matthew D Figley
- Department of Developmental Biology, Washington University Medical School, St. Louis, MO 63110, USA
| | - Xianrong Mao
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA
| | - Alicia Neiner
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA
| | - A Joseph Bloom
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine in Saint Louis, St. Louis, MO 63114, USA
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University Medical School, St. Louis, MO 63110, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine in Saint Louis, St. Louis, MO 63114, USA.
| | - Jeffrey Milbrandt
- Department of Genetics, Washington University Medical School, St. Louis, MO 63110, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine in Saint Louis, St. Louis, MO 63114, USA.
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25
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Hopkins EL, Gu W, Kobe B, Coleman MP. A Novel NAD Signaling Mechanism in Axon Degeneration and its Relationship to Innate Immunity. Front Mol Biosci 2021; 8:703532. [PMID: 34307460 PMCID: PMC8295901 DOI: 10.3389/fmolb.2021.703532] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/28/2021] [Indexed: 12/21/2022] Open
Abstract
Axon degeneration represents a pathological feature of many neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease where axons die before the neuronal soma, and axonopathies, such as Charcot-Marie-Tooth disease and hereditary spastic paraplegia. Over the last two decades, it has slowly emerged that a central signaling pathway forms the basis of this process in many circumstances. This is an axonal NAD-related signaling mechanism mainly regulated by the two key proteins with opposing roles: the NAD-synthesizing enzyme NMNAT2, and SARM1, a protein with NADase and related activities. The crosstalk between the axon survival factor NMNAT2 and pro-degenerative factor SARM1 has been extensively characterized and plays an essential role in maintaining the axon integrity. This pathway can be activated in necroptosis and in genetic, toxic or metabolic disorders, physical injury and neuroinflammation, all leading to axon pathology. SARM1 is also known to be involved in regulating innate immunity, potentially linking axon degeneration to the response to pathogens and intercellular signaling. Understanding this NAD-related signaling mechanism enhances our understanding of the process of axon degeneration and enables a path to the development of drugs for a wide range of neurodegenerative diseases.
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Affiliation(s)
- Eleanor L. Hopkins
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Weixi Gu
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Michael P. Coleman
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
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26
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Zhao YJ, He WM, Zhao ZY, Li WH, Wang QW, Hou YN, Tan Y, Zhang D. Acidic pH irreversibly activates the signaling enzyme SARM1. FEBS J 2021; 288:6783-6794. [PMID: 34213829 DOI: 10.1111/febs.16104] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/06/2021] [Accepted: 07/01/2021] [Indexed: 02/04/2023]
Abstract
SARM1, an executioner in axon degeneration, is an autoinhibitory NAD-consuming enzyme, composed of multiple domains. NMN and its analogs, CZ-48 and VMN, are the only known activators, which can release the inhibitory ARM domain from the enzymatic TIR domain. Here, we document that acid can also activate SARM1, even more efficiently than NMN, possibly via the protonation of the negative residues. Systematic mutagenesis revealed that a single mutation, E689Q in TIR, led to the constitutive activation of SARM1. It forms a salt bridge with R216 in the neighboring ARM, maintaining the autoinhibitory structure. Using this 'acid activation' protocol, mutation K597E was found to inhibit activation, while H685A eliminated SARM1 catalytic activity, revealing two distinct inhibitory mechanisms. The protocol has also been applied to differentiate two classes of chemical inhibitors. NAD, dHNN, disulfiram, CHAPS, and TRX-100 mainly inhibited the activation process, while nicotinamide and Tweens mainly inhibited SARM1 catalysis. Taken together, we demonstrate a new mechanism for SARM1 activation and decipher two distinct inhibitory mechanisms of SARM1.
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Affiliation(s)
- Yong Juan Zhao
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, China.,Ciechanover Institute of Precision and Regenerative Medicine, School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen, China.,Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, China
| | - Wei Ming He
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, China
| | - Zhi Ying Zhao
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, China
| | - Wan Hua Li
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, China.,Ciechanover Institute of Precision and Regenerative Medicine, School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen, China
| | - Qian Wen Wang
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, China
| | - Yun Nan Hou
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen University Town, China
| | - Yongjun Tan
- Department of Biology, College of Arts and Sciences, Saint Louis University, MO, USA
| | - Dapeng Zhang
- Department of Biology, College of Arts and Sciences, Saint Louis University, MO, USA.,Program of Bioinformatics and Computational Biology, College of Arts and Sciences, Saint Louis University, MO, USA
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