1
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Gama AR, Miller T, Venkatesan S, Lange JJ, Wu J, Song X, Bradford D, Unruh JR, Halfmann R. Protein supersaturation powers innate immune signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.20.533581. [PMID: 36993308 PMCID: PMC10055258 DOI: 10.1101/2023.03.20.533581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Innate immunity protects us in youth but turns against us as we age. The reason for this tradeoff is unclear. Seeking a thermodynamic basis, we focused on death fold domains (DFDs), whose ordered polymerization has been stoichiometrically linked to innate immune signal amplification. We hypothesized that soluble ensembles of DFDs function as phase change batteries that store energy via supersaturation and subsequently release it through nucleated polymerization. Using imaging and FRET-based cytometry to characterize the phase behaviors of all 109 human DFDs, we found that the hubs of innate immune signaling networks encode large nucleation barriers that are intrinsically insulated from cross-pathway activation. We showed via optogenetics that supersaturation drives signal amplification and that the inflammasome is constitutively supersaturated in vivo. Our findings reveal that the soluble "inactive" states of adaptor DFDs function as essential, yet impermanent, kinetic barriers to inflammatory cell death, suggesting a thermodynamic driving force for aging.
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Affiliation(s)
| | - Tayla Miller
- Stowers Institute for Medical Research, Kansas City, MO
| | | | | | - Jianzheng Wu
- Stowers Institute for Medical Research, Kansas City, MO
| | - Xiaoqing Song
- Stowers Institute for Medical Research, Kansas City, MO
| | - Dan Bradford
- Stowers Institute for Medical Research, Kansas City, MO
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO
| | - Randal Halfmann
- Stowers Institute for Medical Research, Kansas City, MO
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
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2
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Duan X, Boo ZZ, Chua SL, Chong KHC, Long Z, Yang R, Zhou Y, Janela B, Chotirmall SH, Ginhoux F, Hu Q, Wu B, Yang L. A Bacterial Quorum Sensing Regulated Protease Inhibits Host Immune Responses by Cleaving Death Domains of Innate Immune Adaptors. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304891. [PMID: 37870218 PMCID: PMC10700182 DOI: 10.1002/advs.202304891] [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: 07/18/2023] [Revised: 09/28/2023] [Indexed: 10/24/2023]
Abstract
Innate immune adaptor proteins are critical components of the innate immune system that propagate pro-inflammatory responses from their upstream receptors, and lead to pathogen clearance from the host. Bacterial pathogens have developed strategies to survive inside host cells without triggering the innate immune surveillance in ways that are still not fully understood. Here, it is reported that Pseudomonas aeruginosa induces its quorum sensing mechanism after macrophage engulfment. Further investigation of its secretome identified a quorum sensing regulated product, LasB, is responsible for innate immune suppression depending on the MyD88-mediated signaling. Moreover, it is showed that this specific type of pathogen-mediated innate immune suppression is due to the enzymatic digestion of the death domains of the innate immune adaptors, mainly MyD88, and attributed to LasB's large substrate binding groove. Lastly, it is demonstrated that the secretion of LasB from P. aeruginosa directly contributed to MyD88 degradation within macrophages. Hence, it is discovered an example of bacterial quorum sensing-regulated cellular innate immune suppression by direct cleavage of immune adaptors.
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Affiliation(s)
- Xiangke Duan
- Shenzhen Third People's HospitalThe Second Affiliated Hospital of Southern University of Science and TechnologyNational Clinical Research Center for Infectious DiseaseShenzhen518112P. R. China
- School of MedicineSouthern University of Science and TechnologyShenzhenGuangdong518055P. R. China
- Shenzhen Center for Disease, Control and PreventionShenzhen518055P.R. China
| | - Zhao Zhi Boo
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Song Lin Chua
- Department of Applied Biology and Chemical TechnologyThe Hong Kong Polytechnic UniversityHong Kong SAR999077P. R. China
| | - Kelvin Han Chung Chong
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Ziqi Long
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Renliang Yang
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Yachun Zhou
- Shenzhen Third People's HospitalThe Second Affiliated Hospital of Southern University of Science and TechnologyNational Clinical Research Center for Infectious DiseaseShenzhen518112P. R. China
- School of MedicineSouthern University of Science and TechnologyShenzhenGuangdong518055P. R. China
| | - Baptiste Janela
- Skin Research Institute of SingaporeSingapore308232Singapore
- Lee Kong Chian School of MedicineNanyang Technological UniversitySingapore639798Singapore
| | | | - Florent Ginhoux
- Singapore Immunology NetworkAgency for Science, Technology and Research (A*STAR)8A Biomedical Grove, ImmunosSingapore138648Singapore
| | - Qinghua Hu
- Shenzhen Center for Disease, Control and PreventionShenzhen518055P.R. China
| | - Bin Wu
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- NTU Institute of Structural BiologyNanyang Technological UniversitySingapore636921Singapore
| | - Liang Yang
- Shenzhen Third People's HospitalThe Second Affiliated Hospital of Southern University of Science and TechnologyNational Clinical Research Center for Infectious DiseaseShenzhen518112P. R. China
- School of MedicineSouthern University of Science and TechnologyShenzhenGuangdong518055P. R. China
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3
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Minderman M, Lantermans H, van der Zwaan C, Hoogendijk AJ, van den Biggelaar M, Kersten MJ, Spaargaren M, Pals ST. The oncogenic human B-cell lymphoma MYD88 L265P mutation genocopies activation by phosphorylation at the Toll/interleukin-1 receptor (TIR) domain. Blood Cancer J 2023; 13:125. [PMID: 37591861 PMCID: PMC10435502 DOI: 10.1038/s41408-023-00896-6] [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: 03/12/2023] [Revised: 07/23/2023] [Accepted: 08/01/2023] [Indexed: 08/19/2023] Open
Abstract
MYD88 is the key signaling adaptor-protein for Toll-like and interleukin-1 receptors. A somatic L265P mutation within the Toll/interleukin-1 receptor (TIR) domain of MYD88 is found in 90% of Waldenström macroglobulinemia cases and in a significant subset of diffuse large B-cell lymphomas. MYD88-L265P strongly promotes NF-κB pathway activation, JAK-STAT signaling and lymphoma cell survival. Previous studies have identified other residues of the TIR-domain crucially involved in NF-κB activation, including serine 257 (S257), indicating a potentially important physiological role in the regulation of MYD88 activation. Here, we demonstrate that MYD88 S257 is phosphorylated in B-cell lymphoma cells and that this phosphorylation is required for optimal TLR-induced NF-κB activation. Furthermore, we demonstrate that a phosphomimetic MYD88-S257D mutant promotes MYD88 aggregation, IRAK1 phosphorylation, NF-κB activation and cell growth to a similar extent as the oncogenic L265P mutant. Lastly, we show that expression of MYD88-S257D can rescue cell growth upon silencing of endogenous MYD88-L265P expression in lymphoma cells addicted to oncogenic MYD88 signaling. Our data suggest that the L265P mutation promotes TIR domain homodimerization and NF-κB activation by copying the effect of MY88 phosphorylation at S257, thus providing novel insights into the molecular mechanism underlying the oncogenic activity of MYD88-L265P in B-cell malignancies.
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Affiliation(s)
- Marthe Minderman
- Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC, Location University of Amsterdam, Amsterdam, The Netherlands
- Lymphoma and Myeloma Center Amsterdam - LYMMCARE, Amsterdam, The Netherlands
| | - Hildo Lantermans
- Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC, Location University of Amsterdam, Amsterdam, The Netherlands
- Lymphoma and Myeloma Center Amsterdam - LYMMCARE, Amsterdam, The Netherlands
| | - Carmen van der Zwaan
- Department of Molecular Hematology, Sanquin Research, Amsterdam, The Netherlands
| | - Arie J Hoogendijk
- Department of Molecular Hematology, Sanquin Research, Amsterdam, The Netherlands
| | | | - Marie José Kersten
- Lymphoma and Myeloma Center Amsterdam - LYMMCARE, Amsterdam, The Netherlands
- Department of Hematology, Cancer Center Amsterdam, Amsterdam UMC, Location University of Amsterdam, Amsterdam, The Netherlands
| | - Marcel Spaargaren
- Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC, Location University of Amsterdam, Amsterdam, The Netherlands
- Lymphoma and Myeloma Center Amsterdam - LYMMCARE, Amsterdam, The Netherlands
| | - Steven T Pals
- Department of Pathology, Cancer Center Amsterdam, Amsterdam UMC, Location University of Amsterdam, Amsterdam, The Netherlands.
- Lymphoma and Myeloma Center Amsterdam - LYMMCARE, Amsterdam, The Netherlands.
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4
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Drandi D, Decruyenaere P, Ferrante M, Offner F, Vandesompele J, Ferrero S. Nucleic Acid Biomarkers in Waldenström Macroglobulinemia and IgM-MGUS: Current Insights and Clinical Relevance. Diagnostics (Basel) 2022; 12:diagnostics12040969. [PMID: 35454017 PMCID: PMC9028641 DOI: 10.3390/diagnostics12040969] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/07/2022] [Accepted: 04/09/2022] [Indexed: 12/13/2022] Open
Abstract
Waldenström Macroglobulinemia (WM) is an indolent lymphoplasmacytic lymphoma, characterized by the production of excess immunoglobulin M monoclonal protein. WM belongs to the spectrum of IgM gammopathies, ranging from asymptomatic IgM monoclonal gammopathy of undetermined significance (IgM-MGUS), through IgM-related disorders and asymptomatic WM to symptomatic WM. In recent years, its complex genomic and transcriptomic landscape has been extensively explored, hereby elucidating the biological mechanisms underlying disease onset, progression and therapy response. An increasing number of mutations, cytogenetic abnormalities, and molecular signatures have been described that have diagnostic, phenotype defining or prognostic implications. Moreover, cell-free nucleic acid biomarkers are increasingly being investigated, benefiting the patient in a minimally invasive way. This review aims to provide an extensive overview of molecular biomarkers in WM and IgM-MGUS, considering current shortcomings, as well as potential future applications in a precision medicine approach.
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Affiliation(s)
- Daniela Drandi
- Department of Molecular Biotechnology and Health Sciences, Hematology Division, University of Torino, 10126 Torino, Italy; (M.F.); (S.F.)
- Correspondence: (D.D.); (P.D.)
| | - Philippe Decruyenaere
- Department of Hematology, Ghent University Hospital, 9000 Ghent, Belgium;
- OncoRNALab, Cancer Research Institute Ghent (CRIG), 9000 Ghent, Belgium;
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
- Correspondence: (D.D.); (P.D.)
| | - Martina Ferrante
- Department of Molecular Biotechnology and Health Sciences, Hematology Division, University of Torino, 10126 Torino, Italy; (M.F.); (S.F.)
| | - Fritz Offner
- Department of Hematology, Ghent University Hospital, 9000 Ghent, Belgium;
| | - Jo Vandesompele
- OncoRNALab, Cancer Research Institute Ghent (CRIG), 9000 Ghent, Belgium;
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
| | - Simone Ferrero
- Department of Molecular Biotechnology and Health Sciences, Hematology Division, University of Torino, 10126 Torino, Italy; (M.F.); (S.F.)
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5
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Song J, Chen D, Pan Y, Shi X, Liu Q, Lu X, Xu X, Chen G, Cai Y. Discovery of a Novel MyD88 Inhibitor M20 and Its Protection Against Sepsis-Mediated Acute Lung Injury. Front Pharmacol 2021; 12:775117. [PMID: 34912226 PMCID: PMC8666603 DOI: 10.3389/fphar.2021.775117] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Myeloid differentiation factor 88 (MyD88) is a hub protein in the Toll-like receptor signaling pathway, which acts as a master switch for numerous inflammatory diseases, including acute lung injury (ALI). Although this protein is considered as a crucial therapeutic target, there are currently no clinically approved MyD88-targeting drugs. Based on previous literature, here we report the discovery via computer-aided drug design (CADD) of a small molecule, M20, which functions as a novel MyD88 inhibitor to efficiently relieve lipopolysaccharide-induced inflammation both in vitro and in vivo. Computational chemistry, surface plasmon resonance detection (SPR) and biological experiments demonstrated that M20 forms an important interaction with the MyD88-Toll/interleukin-1 receptor domain and thereby inhibits the protein dimerization. Taken together, this study found a MyD88 inhibitor, M20, with a novel skeleton, which provides a crucial understanding in the development and modification of MyD88 inhibitors. Meanwhile, the favorable bioactivity of the hit compound is also conducive to the treatment of acute lung injury or other more inflammatory diseases.
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Affiliation(s)
- Jiali Song
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Daoxing Chen
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Yingqiao Pan
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Xueqin Shi
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Qian Liu
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Xiaoyao Lu
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Ximing Xu
- Key Laboratory of Marine Drugs of Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Center for Innovation Marine Drug Screening & Evaluation, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.,Marine Biomedical Research Institute of Qingdao, Qingdao, China
| | - Gaozhi Chen
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
| | - Yuepiao Cai
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, China
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6
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Nimma S, Gu W, Maruta N, Li Y, Pan M, Saikot FK, Lim BYJ, McGuinness HY, Zaoti ZF, Li S, Desa S, Manik MK, Nanson JD, Kobe B. Structural Evolution of TIR-Domain Signalosomes. Front Immunol 2021; 12:784484. [PMID: 34868065 PMCID: PMC8635717 DOI: 10.3389/fimmu.2021.784484] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 10/25/2021] [Indexed: 01/23/2023] Open
Abstract
TIR (Toll/interleukin-1 receptor/resistance protein) domains are cytoplasmic domains widely found in animals and plants, where they are essential components of the innate immune system. A key feature of TIR-domain function in signaling is weak and transient self-association and association with other TIR domains. An additional new role of TIR domains as catalytic enzymes has been established with the recent discovery of NAD+-nucleosidase activity by several TIR domains, mostly involved in cell-death pathways. Although self-association of TIR domains is necessary in both cases, the functional specificity of TIR domains is related in part to the nature of the TIR : TIR interactions in the respective signalosomes. Here, we review the well-studied TIR domain-containing proteins involved in eukaryotic immunity, focusing on the structures, interactions and their corresponding functional roles. Structurally, the signalosomes fall into two separate groups, the scaffold and enzyme TIR-domain assemblies, both of which feature open-ended complexes with two strands of TIR domains, but differ in the orientation of the two strands. We compare and contrast how TIR domains assemble and signal through distinct scaffolding and enzymatic roles, ultimately leading to distinct cellular innate-immunity and cell-death outcomes.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
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7
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Bhumkar A, Magnan C, Lau D, Jun ESW, Dzamko N, Gambin Y, Sierecki E. Single-Molecule Counting Coupled to Rapid Amplification Enables Detection of α-Synuclein Aggregates in Cerebrospinal Fluid of Parkinson's Disease Patients. Angew Chem Int Ed Engl 2021; 60:11874-11883. [PMID: 33511725 PMCID: PMC8251908 DOI: 10.1002/anie.202014898] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/13/2021] [Indexed: 12/16/2022]
Abstract
α-Synuclein aggregation is a hallmark of Parkinson's disease and a promising biomarker for early detection and assessment of disease progression. The prospect of a molecular test for Parkinson's disease is materializing with the recent developments of detection methods based on amplification of synuclein seeds (e.g. RT-QuIC or PMCA). Here we adapted single-molecule counting methods for the detection of α-synuclein aggregates in cerebrospinal fluid (CSF), using a simple 3D printed microscope. Single-molecule methods enable to probe the early events in the amplification process used in RT-QuIC and a precise counting of ThT-positive aggregates. Importantly, the use of single-molecule counting also allows a refined characterization of the samples and fingerprinting of the protein aggregates present in CSF of patients. The fingerprinting of size and reactivity of individual aggregate shows a unique signature for each PD patients compared to controls and may provide new insights on synucleinopathies in the future.
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Affiliation(s)
- Akshay Bhumkar
- EMBL-Australia node in Single Molecule Science and School of Medical SciencesThe University of New South WalesSydneyNSW2052Australia
| | - Chloe Magnan
- EMBL-Australia node in Single Molecule Science and School of Medical SciencesThe University of New South WalesSydneyNSW2052Australia
| | - Derrick Lau
- EMBL-Australia node in Single Molecule Science and School of Medical SciencesThe University of New South WalesSydneyNSW2052Australia
| | - Eugene Soh Wei Jun
- EMBL-Australia node in Single Molecule Science and School of Medical SciencesThe University of New South WalesSydneyNSW2052Australia
| | - Nicolas Dzamko
- Brain and Mind Centre and the School of Medical SciencesThe University of SydneySydneyNSW2006Australia
| | - Yann Gambin
- EMBL-Australia node in Single Molecule Science and School of Medical SciencesThe University of New South WalesSydneyNSW2052Australia
| | - Emma Sierecki
- EMBL-Australia node in Single Molecule Science and School of Medical SciencesThe University of New South WalesSydneyNSW2052Australia
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8
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Bhumkar A, Magnan C, Lau D, Jun ESW, Dzamko N, Gambin Y, Sierecki E. Single‐Molecule Counting Coupled to Rapid Amplification Enables Detection of α‐Synuclein Aggregates in Cerebrospinal Fluid of Parkinson's Disease Patients. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202014898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Akshay Bhumkar
- EMBL-Australia node in Single Molecule Science and School of Medical Sciences The University of New South Wales Sydney NSW 2052 Australia
| | - Chloe Magnan
- EMBL-Australia node in Single Molecule Science and School of Medical Sciences The University of New South Wales Sydney NSW 2052 Australia
| | - Derrick Lau
- EMBL-Australia node in Single Molecule Science and School of Medical Sciences The University of New South Wales Sydney NSW 2052 Australia
| | - Eugene Soh Wei Jun
- EMBL-Australia node in Single Molecule Science and School of Medical Sciences The University of New South Wales Sydney NSW 2052 Australia
| | - Nicolas Dzamko
- Brain and Mind Centre and the School of Medical Sciences The University of Sydney Sydney NSW 2006 Australia
| | - Yann Gambin
- EMBL-Australia node in Single Molecule Science and School of Medical Sciences The University of New South Wales Sydney NSW 2052 Australia
| | - Emma Sierecki
- EMBL-Australia node in Single Molecule Science and School of Medical Sciences The University of New South Wales Sydney NSW 2052 Australia
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9
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Clabbers MTB, Holmes S, Muusse TW, Vajjhala PR, Thygesen SJ, Malde AK, Hunter DJB, Croll TI, Flueckiger L, Nanson JD, Rahaman MH, Aquila A, Hunter MS, Liang M, Yoon CH, Zhao J, Zatsepin NA, Abbey B, Sierecki E, Gambin Y, Stacey KJ, Darmanin C, Kobe B, Xu H, Ve T. MyD88 TIR domain higher-order assembly interactions revealed by microcrystal electron diffraction and serial femtosecond crystallography. Nat Commun 2021; 12:2578. [PMID: 33972532 PMCID: PMC8110528 DOI: 10.1038/s41467-021-22590-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/18/2021] [Indexed: 02/03/2023] Open
Abstract
MyD88 and MAL are Toll-like receptor (TLR) adaptors that signal to induce pro-inflammatory cytokine production. We previously observed that the TIR domain of MAL (MALTIR) forms filaments in vitro and induces formation of crystalline higher-order assemblies of the MyD88 TIR domain (MyD88TIR). These crystals are too small for conventional X-ray crystallography, but are ideally suited to structure determination by microcrystal electron diffraction (MicroED) and serial femtosecond crystallography (SFX). Here, we present MicroED and SFX structures of the MyD88TIR assembly, which reveal a two-stranded higher-order assembly arrangement of TIR domains analogous to that seen previously for MALTIR. We demonstrate via mutagenesis that the MyD88TIR assembly interfaces are critical for TLR4 signaling in vivo, and we show that MAL promotes unidirectional assembly of MyD88TIR. Collectively, our studies provide structural and mechanistic insight into TLR signal transduction and allow a direct comparison of the MicroED and SFX techniques.
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Affiliation(s)
- Max T B Clabbers
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California, USA
| | - Susannah Holmes
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Timothy W Muusse
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Parimala R Vajjhala
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Sara J Thygesen
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Alpeshkumar K Malde
- Institute for Glycomics, Griffith University, Southport, Queensland, Australia
| | - Dominic J B Hunter
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- EMBL Australia Node in Single Molecule Science, University of New South Wales, Kensington, New South Wales, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Tristan I Croll
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Leonie Flueckiger
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Jeffrey D Nanson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Md Habibur Rahaman
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Andrew Aquila
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | - Mark S Hunter
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | - Mengning Liang
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | - Chun Hong Yoon
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California, USA
| | - Jingjing Zhao
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Nadia A Zatsepin
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Brian Abbey
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Emma Sierecki
- EMBL Australia Node in Single Molecule Science, University of New South Wales, Kensington, New South Wales, Australia
| | - Yann Gambin
- EMBL Australia Node in Single Molecule Science, University of New South Wales, Kensington, New South Wales, Australia
| | - Katryn J Stacey
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Connie Darmanin
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia.
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.
| | - Hongyi Xu
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden.
| | - Thomas Ve
- Institute for Glycomics, Griffith University, Southport, Queensland, Australia.
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10
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Deliz-Aguirre R, Cao F, Gerpott FHU, Auevechanichkul N, Chupanova M, Mun Y, Ziska E, Taylor MJ. MyD88 oligomer size functions as a physical threshold to trigger IL1R Myddosome signaling. J Cell Biol 2021; 220:212080. [PMID: 33956941 PMCID: PMC8105725 DOI: 10.1083/jcb.202012071] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/24/2021] [Accepted: 04/07/2021] [Indexed: 11/22/2022] Open
Abstract
A recurring feature of innate immune receptor signaling is the self-assembly of signaling proteins into oligomeric complexes. The Myddosome is an oligomeric complex that is required to transmit inflammatory signals from TLR/IL1Rs and consists of MyD88 and IRAK family kinases. However, the molecular basis for how Myddosome proteins self-assemble and regulate intracellular signaling remains poorly understood. Here, we developed a novel assay to analyze the spatiotemporal dynamics of IL1R and Myddosome signaling in live cells. We found that MyD88 oligomerization is inducible and initially reversible. Moreover, the formation of larger, stable oligomers consisting of more than four MyD88s triggers the sequential recruitment of IRAK4 and IRAK1. Notably, genetic knockout of IRAK4 enhanced MyD88 oligomerization, indicating that IRAK4 controls MyD88 oligomer size and growth. MyD88 oligomer size thus functions as a physical threshold to trigger downstream signaling. These results provide a mechanistic basis for how protein oligomerization might function in cell signaling pathways.
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Affiliation(s)
| | - Fakun Cao
- Max Planck Institute for Infection Biology, Berlin, Germany
| | | | | | | | - YeVin Mun
- Max Planck Institute for Infection Biology, Berlin, Germany
| | - Elke Ziska
- Max Planck Institute for Infection Biology, Berlin, Germany
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11
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Emodin protects against intestinal and lung injury induced by acute intestinal injury by modulating SP-A and TLR4/NF-κB pathway. Biosci Rep 2021; 40:226403. [PMID: 32915230 PMCID: PMC7517261 DOI: 10.1042/bsr20201605] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 09/02/2020] [Accepted: 09/10/2020] [Indexed: 12/15/2022] Open
Abstract
Objective: Our aim was to investigate the effect of emodin on intestinal and lung injury induced by acute intestinal injury in rats and explore potential molecular mechanisms. Methods: Healthy male Sprague–Dawley (SD) rats were randomly divided into five groups (n=10, each group): normal group; saline group; acute intestinal injury model group; model + emodin group; model+NF-κB inhibitor pynolidine dithiocarbamate (PDTC) group. Histopathological changes in intestine/lung tissues were observed by Hematoxylin and Eosin (H&E) and terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling (TUNEL) staining. Serum IKBα, p-IKBα, surfactant protein-A (SP-A) and toll-like receptor 4 (TLR4) levels were examined using enzyme-linked immunosorbent assay (ELISA). RT-qPCR was performed to detect the mRNA expression levels of IKBα, SP-A and TLR4 in intestine/lung tissues. Furthermore, the protein expression levels of IKBα, p-IKBα, SP-A and TLR4 were detected by Western blot. Results: The pathological injury of intestinal/lung tissues was remarkedly ameliorated in models treated with emodin and PDTC. Furthermore, the intestinal/lung injury scores were significantly decreased after emodin or PDTC treatment. TUNEL results showed that both emodin and PDTC treatment distinctly attenuated the apoptosis of intestine/lung tissues induced by acute intestinal injury. At the mRNA level, emodin significantly increased the expression levels of SP-A and decreased the expression levels of IKBα and TLR4 in intestine/lung tissues. According to ELISA and Western blot, emodin remarkedly inhibited the expression of p-IKBα protein and elevated the expression of SP-A and TLR4 in serum and intestine/lung tissues induced by acute intestinal injury. Conclusion: Our findings suggested that emodin could protect against intestinal and lung injury induced by acute intestinal injury by modulating SP-A and TLR4/NF-κB pathway.
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12
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Lau D, Walsh JC, Dickson CF, Tuckwell A, Stear JH, Hunter DJB, Bhumkar A, Shah V, Turville SG, Sierecki E, Gambin Y, Böcking T, Jacques DA. Rapid HIV-1 Capsid Interaction Screening Using Fluorescence Fluctuation Spectroscopy. Anal Chem 2021; 93:3786-3793. [PMID: 33593049 DOI: 10.1021/acs.analchem.0c04250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The HIV capsid is a multifunctional protein capsule that mediates the delivery of the viral genetic material into the nucleus of the target cell. Host cell proteins bind to a number of repeating binding sites on the capsid to regulate steps in the replication cycle. Here, we develop a fluorescence fluctuation spectroscopy method using self-assembled capsid particles as the bait to screen for fluorescence-labeled capsid-binding analytes ("prey" molecules) in solution. The assay capitalizes on the property of the HIV capsid as a multivalent interaction platform, facilitating high sensitivity detection of multiple prey molecules that have accumulated onto capsids as spikes in fluorescence intensity traces. By using a scanning stage, we reduced the measurement time to 10 s without compromising on sensitivity, providing a rapid binding assay for screening libraries of potential capsid interactors. The assay can also identify interfaces for host molecule binding by using capsids with defects in known interaction interfaces. Two-color coincidence detection using the fluorescent capsid as the bait further allows the quantification of binding levels and determination of binding affinities. Overall, the assay provides new tools for the discovery and characterization of molecules used by the HIV capsid to orchestrate infection. The measurement principle can be extended for the development of sensitive interaction assays, utilizing natural or synthetic multivalent scaffolds as analyte-binding platforms.
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Affiliation(s)
- Derrick Lau
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - James C Walsh
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Claire F Dickson
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Andrew Tuckwell
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Jeffrey H Stear
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Dominic J B Hunter
- The Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Akshay Bhumkar
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Vaibhav Shah
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Stuart G Turville
- The Kirby Institute, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Emma Sierecki
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Yann Gambin
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Till Böcking
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - David A Jacques
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
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13
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Moustaqil M, Ollivier E, Chiu HP, Van Tol S, Rudolffi-Soto P, Stevens C, Bhumkar A, Hunter DJB, Freiberg AN, Jacques D, Lee B, Sierecki E, Gambin Y. SARS-CoV-2 proteases PLpro and 3CLpro cleave IRF3 and critical modulators of inflammatory pathways (NLRP12 and TAB1): implications for disease presentation across species. Emerg Microbes Infect 2021; 10:178-195. [PMID: 33372854 PMCID: PMC7850364 DOI: 10.1080/22221751.2020.1870414] [Citation(s) in RCA: 156] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The genome of SARS-CoV-2 encodes two viral proteases (NSP3/papain-like protease and NSP5/3C-like protease) that are responsible for cleaving viral polyproteins during replication. Here, we discovered new functions of the NSP3 and NSP5 proteases of SARS-CoV-2, demonstrating that they could directly cleave proteins involved in the host innate immune response. We identified 3 proteins that were specifically and selectively cleaved by NSP3 or NSP5: IRF-3, and NLRP12 and TAB1, respectively. Direct cleavage of IRF3 by NSP3 could explain the blunted Type-I IFN response seen during SARS-CoV-2 infections while NSP5 mediated cleavage of NLRP12 and TAB1 point to a molecular mechanism for enhanced production of cytokines and inflammatory response observed in COVID-19 patients. We demonstrate that in the mouse NLRP12 protein, one of the recognition site is not cleaved in our in-vitro assay. We pushed this comparative alignment of IRF-3 and NLRP12 homologs and show that the lack or presence of cognate cleavage motifs in IRF-3 and NLRP12 could contribute to the presentation of disease in cats and tigers, for example. Our findings provide an explanatory framework for indepth studies into the pathophysiology of COVID-19.
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Affiliation(s)
- Mehdi Moustaqil
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, Australia
| | - Emma Ollivier
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, Australia
| | - Hsin-Ping Chiu
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sarah Van Tol
- Department of Microbiology and Immunology, Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, TX, USA
| | - Paulina Rudolffi-Soto
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, Australia
| | - Christian Stevens
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Akshay Bhumkar
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, Australia
| | - Dominic J B Hunter
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, Australia.,Institute for Molecular Biosciences, The University of Queensland, St Lucia, Australia
| | - Alexander N Freiberg
- Department of Pathology, Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, TX, USA
| | - David Jacques
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, Australia
| | - Benhur Lee
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Emma Sierecki
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, Australia
| | - Yann Gambin
- EMBL Australia Node for Single Molecule Sciences, and School of Medical Sciences, Botany Road, The University of New South Wales, Sydney, Australia
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14
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Rodríguez Gama A, Miller T, Halfmann R. Mechanics of a molecular mousetrap-nucleation-limited innate immune signaling. Biophys J 2021; 120:1150-1160. [PMID: 33460595 PMCID: PMC8059202 DOI: 10.1016/j.bpj.2021.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/17/2022] Open
Abstract
Innate immune responses, such as cell death and inflammatory signaling, are typically switch-like in nature. They also involve "prion-like" self-templating polymerization of one or more signaling proteins into massive macromolecular assemblies known as signalosomes. Despite the wealth of atomic-resolution structural information on signalosomes, how the constituent polymers nucleate and whether the switch-like nature of that event at the molecular scale relates to the digital nature of innate immune signaling at the cellular scale remains unknown. In this perspective, we review current knowledge of innate immune signalosome assembly, with an emphasis on structural constraints that allow the proteins to accumulate in inactive soluble forms poised for abrupt polymerization. We propose that structurally encoded nucleation barriers to protein polymerization kinetically regulate the corresponding pathways, which allows for extremely sensitive, rapid, and decisive signaling upon pathogen detection. We discuss how nucleation barriers satisfy the rigorous on-demand functions of the innate immune system but also predispose the system to precocious activation that may contribute to progressive age-associated inflammation.
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Affiliation(s)
| | - Tayla Miller
- Stowers Institute for Medical Research, Kansas City, Missouri
| | - Randal Halfmann
- Stowers Institute for Medical Research, Kansas City, Missouri; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas.
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15
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Cobbling Together the Myddosome. Structure 2020; 28:598-600. [DOI: 10.1016/j.str.2020.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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16
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Moncrieffe MC, Bollschweiler D, Li B, Penczek PA, Hopkins L, Bryant CE, Klenerman D, Gay NJ. MyD88 Death-Domain Oligomerization Determines Myddosome Architecture: Implications for Toll-like Receptor Signaling. Structure 2020; 28:281-289.e3. [PMID: 31995744 PMCID: PMC7054835 DOI: 10.1016/j.str.2020.01.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/26/2019] [Accepted: 01/07/2020] [Indexed: 01/12/2023]
Abstract
Toll-like receptors (TLRs) are pivotal in triggering the innate immune response to pathogen infection. Ligand binding induces receptor dimerization which facilitates the recruitment of other post-receptor signal transducers into a complex signalosome, the Myddosome. Central to this process is Myeloid differentiation primary response 88 (MyD88), which is required by almost all TLRs, and signaling is thought to proceed via the stepwise, sequential assembly of individual components. Here, we show that the death domains of human MyD88 spontaneously and reversibly associate to form helical filaments in vitro. A 3.1-Å cryoelectron microscopy structure reveals that the architecture of the filament is identical to that of the 6:4 MyD88-IRAK4-IRAK2 hetero-oligomeric Myddosome. Additionally, the death domain of IRAK4 interacts with the filaments to reconstitute the non-stoichiometric 6:4 MyD88-IRAK4 complex. Together, these data suggest that intracellularly, the MyD88 scaffold may be pre-formed and poised for recruitment of IRAKs on receptor activation and TIR engagement.
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Affiliation(s)
| | | | - Bing Li
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Pawel A Penczek
- Department of Biochemistry & Molecular Biology, The University of Texas, McGovern Medical School, Houston, TX 77030, USA
| | - Lee Hopkins
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | - Clare E Bryant
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Nicholas J Gay
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
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17
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O'Carroll A, Coyle J, Gambin Y. Prions and Prion-like assemblies in neurodegeneration and immunity: The emergence of universal mechanisms across health and disease. Semin Cell Dev Biol 2019; 99:115-130. [PMID: 31818518 DOI: 10.1016/j.semcdb.2019.11.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 11/22/2019] [Indexed: 02/07/2023]
Abstract
Prion-like behaviour is an abrupt process, an "all-or-nothing" transition between a monomeric species and an "infinite" fibrillated form. Once a nucleation point is formed, the process is unstoppable as fibrils self-propagate by recruiting and converting all monomers into the amyloid fold. After the "mad cow" episode, prion diseases have made the headlines, but more and more prion-like behaviours have emerged in neurodegenerative diseases, where formation of fibrils and large conglomerates of proteins deeply disrupt the cell homeostasis. More interestingly, in the last decade, examples emerged to suggest that prion-like conversion can be used as a positive gain of function, for memory storage or structural scaffolding. More recent experiments show that we are only seeing the tip of the iceberg and that, for example, prion-like amplification is found in many pathways of the immune response. In innate immunity, receptors on the cellular surface or within the cells 'sense' danger and propagate this information as signal, through protein-protein interactions (PPIs) between 'receptor', 'adaptor' and 'effector' proteins. In innate immunity, the smallest signal of a foreign element or pathogen needs to trigger a macroscopic signal output, and it was found that adaptor polymerize to create an extreme signal amplification. Interestingly, our body uses multiple structural motifs to create large signalling platform; a few innate proteins use amyloid scaffolds but most of the polymers discovered are composed by self-assembly in helical filaments. Some of these helical assemblies even have intercellular "contamination" in a "true" prion action, as demonstrated for ASC specks and MyD88 filaments. Here, we will describe the current knowledge in neurodegenerative diseases and innate immunity and show how these two very different fields can cross-seed discoveries.
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Affiliation(s)
- Ailis O'Carroll
- EMBL Australia Node in Single Molecule Sciences, and School of Medical Sciences, Faculty of Edicine, The University of New South Wales, Sydney, Australia
| | - Joanne Coyle
- EMBL Australia Node in Single Molecule Sciences, and School of Medical Sciences, Faculty of Edicine, The University of New South Wales, Sydney, Australia
| | - Yann Gambin
- EMBL Australia Node in Single Molecule Sciences, and School of Medical Sciences, Faculty of Edicine, The University of New South Wales, Sydney, Australia.
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18
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Abstract
A paper published in BMC Biology characterises biophysically oligomeric and filamentous structures formed spontaneously by the Toll-like receptor signalling adaptor MyD88. Naturally occurring mutants of MyD88 that cause immunodeficiency are unable to form these structures. By contrast a somatic mutant that promotes the survival of tumour cells forms oligomers much more readily than the wild-type protein. These findings suggest that assembly of oligomeric MyD88 is critical for the regulation of inflammatory signalling.
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Affiliation(s)
- Nicholas J Gay
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK.
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