1
|
Preedy MK, White MRH, Tergaonkar V. Cellular heterogeneity in TNF/TNFR1 signalling: live cell imaging of cell fate decisions in single cells. Cell Death Dis 2024; 15:202. [PMID: 38467621 PMCID: PMC10928192 DOI: 10.1038/s41419-024-06559-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 02/07/2024] [Accepted: 02/13/2024] [Indexed: 03/13/2024]
Abstract
Cellular responses to TNF are inherently heterogeneous within an isogenic cell population and across different cell types. TNF promotes cell survival by activating pro-inflammatory NF-κB and MAPK signalling pathways but may also trigger apoptosis and necroptosis. Following TNF stimulation, the fate of individual cells is governed by the balance of pro-survival and pro-apoptotic signalling pathways. To elucidate the molecular mechanisms driving heterogenous responses to TNF, quantifying TNF/TNFR1 signalling at the single-cell level is crucial. Fluorescence live-cell imaging techniques offer real-time, dynamic insights into molecular processes in single cells, allowing for detection of rapid and transient changes, as well as identification of subpopulations, that are likely to be missed with traditional endpoint assays. Whilst fluorescence live-cell imaging has been employed extensively to investigate TNF-induced inflammation and TNF-induced cell death, it has been underutilised in studying the role of TNF/TNFR1 signalling pathway crosstalk in guiding cell-fate decisions in single cells. Here, we outline the various opportunities for pathway crosstalk during TNF/TNFR1 signalling and how these interactions may govern heterogenous responses to TNF. We also advocate for the use of live-cell imaging techniques to elucidate the molecular processes driving cell-to-cell variability in single cells. Understanding and overcoming cellular heterogeneity in response to TNF and modulators of the TNF/TNFR1 signalling pathway could lead to the development of targeted therapies for various diseases associated with aberrant TNF/TNFR1 signalling, such as rheumatoid arthritis, metabolic syndrome, and cancer.
Collapse
Affiliation(s)
- Marcus K Preedy
- Laboratory of NF-κB Signalling, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Singapore
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, D3308, Dover Street, Manchester, M13 9PT, England, UK
| | - Michael R H White
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, D3308, Dover Street, Manchester, M13 9PT, England, UK.
| | - Vinay Tergaonkar
- Laboratory of NF-κB Signalling, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Singapore.
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 8 Medical Drive, MD7, Singapore, 117596, Singapore.
| |
Collapse
|
2
|
Bacher S, Schmitz ML. Open questions in the NF-κB field. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119469. [PMID: 37951506 DOI: 10.1016/j.bbamcr.2023.119469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/23/2023] [Accepted: 03/23/2023] [Indexed: 11/14/2023]
Abstract
A variety of stress signals leads to activation of the inducible transcription factor NF-κB, one of the master regulators of the innate immune response. Despite a wealth of information available on the NF-κB core components and its control by different activation pathways and negative feedback loops, several levels of complexity hamper our understanding of the system. This has also contributed to the limited success of NF-κB inhibitors in the clinic and explains some of their unexpected effects. Here we consider the molecular and cellular events generating this complexity at all levels and point to a number of unresolved questions in the field. We also discuss potential future experimental and computational strategies to provide a deeper understanding of NF-κB and its coregulatory signaling networks.
Collapse
Affiliation(s)
- Susanne Bacher
- Institute of Biochemistry, Justus Liebig University Giessen (Germany), Member of the German Center for Lung Research (DZL), Germany
| | - M Lienhard Schmitz
- Institute of Biochemistry, Justus Liebig University Giessen (Germany), Member of the German Center for Lung Research (DZL), Germany.
| |
Collapse
|
3
|
DiRusso CJ, DeMaria AM, Wong J, Wang W, Jordanides JJ, Whitty A, Allen KN, Gilmore TD. A conserved core region of the scaffold NEMO is essential for signal-induced conformational change and liquid-liquid phase separation. J Biol Chem 2023; 299:105396. [PMID: 37890781 PMCID: PMC10694592 DOI: 10.1016/j.jbc.2023.105396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/05/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Scaffold proteins help mediate interactions between protein partners, often to optimize intracellular signaling. Herein, we use comparative, biochemical, biophysical, molecular, and cellular approaches to investigate how the scaffold protein NEMO contributes to signaling in the NF-κB pathway. Comparison of NEMO and the related protein optineurin from a variety of evolutionarily distant organisms revealed that a central region of NEMO, called the Intervening Domain (IVD), is conserved between NEMO and optineurin. Previous studies have shown that this central core region of the IVD is required for cytokine-induced activation of IκB kinase (IKK). We show that the analogous region of optineurin can functionally replace the core region of the NEMO IVD. We also show that an intact IVD is required for the formation of disulfide-bonded dimers of NEMO. Moreover, inactivating mutations in this core region abrogate the ability of NEMO to form ubiquitin-induced liquid-liquid phase separation droplets in vitro and signal-induced puncta in vivo. Thermal and chemical denaturation studies of truncated NEMO variants indicate that the IVD, while not intrinsically destabilizing, can reduce the stability of surrounding regions of NEMO due to the conflicting structural demands imparted on this region by flanking upstream and downstream domains. This conformational strain in the IVD mediates allosteric communication between the N- and C-terminal regions of NEMO. Overall, these results support a model in which the IVD of NEMO participates in signal-induced activation of the IKK/NF-κB pathway by acting as a mediator of conformational changes in NEMO.
Collapse
Affiliation(s)
| | - Anthony M DeMaria
- Department of Chemistry, Boston University, Boston, Massachusetts, USA
| | - Judy Wong
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Wei Wang
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Jack J Jordanides
- Department of Chemistry, Boston University, Boston, Massachusetts, USA
| | - Adrian Whitty
- Department of Chemistry, Boston University, Boston, Massachusetts, USA
| | - Karen N Allen
- Department of Chemistry, Boston University, Boston, Massachusetts, USA.
| | - Thomas D Gilmore
- Department of Biology, Boston University, Boston, Massachusetts, USA.
| |
Collapse
|
4
|
Park HB, Baek KH. Current and future directions of USP7 interactome in cancer study. Biochim Biophys Acta Rev Cancer 2023; 1878:188992. [PMID: 37775071 DOI: 10.1016/j.bbcan.2023.188992] [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: 07/28/2023] [Revised: 09/14/2023] [Accepted: 09/23/2023] [Indexed: 10/01/2023]
Abstract
The ubiquitin-proteasome system (UPS) is an essential protein quality controller for regulating protein homeostasis and autophagy. Ubiquitination is a protein modification process that involves the binding of one or more ubiquitins to substrates through a series of enzymatic processes. These include ubiquitin-activating enzymes (E1), ubiquitin-conjugating enzymes (E2), and ubiquitin ligases (E3). Conversely, deubiquitination is a reverse process that removes ubiquitin from substrates via deubiquitinating enzymes (DUBs). Dysregulation of ubiquitination-related enzymes can lead to various human diseases, including cancer, through the modulation of protein ubiquitination. The most structurally and functionally studied DUB is the ubiquitin-specific protease 7 (USP7). Both the TRAF and UBL domains of USP7 are known to bind to the [P/A/E]-X-X-S or K-X-X-X-K motif of substrates. USP7 has been shown to be involved in cancer pathogenesis by binding with numerous substrates. Recently, a novel substrate of USP7 was discovered through a systemic analysis of its binding motif. This review summarizes the currently discovered substrates and cellular functions of USP7 in cancer and suggests putative substrates of USP7 through a comprehensive systemic analysis.
Collapse
Affiliation(s)
- Hong-Beom Park
- Department of Convergence, CHA University, Gyeonggi-Do 13488, Republic of Korea
| | - Kwang-Hyun Baek
- Department of Convergence, CHA University, Gyeonggi-Do 13488, Republic of Korea; International Ubiquitin Center(,) CHA University, Gyeonggi-Do 13488, Republic of Korea.
| |
Collapse
|
5
|
Almeida SM, Ivantsiv S, Niibori R, Dunham WH, Green BA, Zhao L, Gingras AC, Cordes SP. An interaction between OTULIN and SCRIB uncovers roles for linear ubiquitination in planar cell polarity. Dis Model Mech 2023; 16:dmm049762. [PMID: 37589075 PMCID: PMC10445738 DOI: 10.1242/dmm.049762] [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: 07/12/2022] [Accepted: 07/17/2023] [Indexed: 08/18/2023] Open
Abstract
Planar cell polarity (PCP) plays critical roles in developmental and homeostatic processes. Membrane presentation of PCP complexes containing Van Gogh-like (VANGL) transmembrane proteins is central to PCP and can be directed by the scaffold protein scribble (SCRIB). The role atypical linear ubiquitin (Met1-Ub) chains might play in PCP is unknown. Here, HEK293 cell-based interactomic analyses of the Met1-Ub deubiquitinase OTULIN revealed that OTULIN can interact with SCRIB. Moreover, Met1-Ub chains associated with VANGL2 and PRICKLE1, but not SCRIB, can direct VANGL2 surface presentation. Mouse embryos lacking Otulin showed variable neural tube malformations, including rare open neural tubes, a deficit associated with PCP disruption in mice. In Madin-Darby canine kidney cells, in which the enrichment of VANGL2-GFP proteins at cell-cell contacts represents activated PCP complexes, endogenous OTULIN was recruited to these sites. In the human MDA-MB-231 breast cancer cell model, OTULIN loss caused deficits in Wnt5a-induced filopodia extension and trafficking of transfected HA-VANGL2. Taken together, these findings support a role for linear (de)ubiquitination in PCP signaling. The association of Met1-Ub chains with PCP complex components offers new opportunities for integrating PCP signaling with OTULIN-dependent immune and inflammatory pathways.
Collapse
Affiliation(s)
- Stephanie M. Almeida
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Ave, Toronto, ON M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Sofiia Ivantsiv
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Ave, Toronto, ON M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Rieko Niibori
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Ave, Toronto, ON M5G 1X5, Canada
| | - Wade H. Dunham
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Ave, Toronto, ON M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Brooke A. Green
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Ave, Toronto, ON M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Liang Zhao
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Ave, Toronto, ON M5G 1X5, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Ave, Toronto, ON M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Sabine P. Cordes
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Ave, Toronto, ON M5G 1X5, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| |
Collapse
|
6
|
DiRusso CJ, DeMaria AM, Wong J, Jordanides JJ, Whitty A, Allen KN, Gilmore TD. A Conserved Core Region of the Scaffold NEMO is Essential for Signal-induced Conformational Change and Liquid-liquid Phase Separation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.542299. [PMID: 37292615 PMCID: PMC10245932 DOI: 10.1101/2023.05.25.542299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Scaffold proteins help mediate interactions between protein partners, often to optimize intracellular signaling. Herein, we use comparative, biochemical, biophysical, molecular, and cellular approaches to investigate how the scaffold protein NEMO contributes to signaling in the NF-κB pathway. Comparison of NEMO and the related protein optineurin from a variety of evolutionarily distant organisms revealed that a central region of NEMO, called the Intervening Domain (IVD), is conserved between NEMO and optineurin. Previous studies have shown that this central core region of the IVD is required for cytokine-induced activation of IκB kinase (IKK). We show that the analogous region of optineurin can functionally replace the core region of the NEMO IVD. We also show that an intact IVD is required for the formation of disulfide-bonded dimers of NEMO. Moreover, inactivating mutations in this core region abrogate the ability of NEMO to form ubiquitin-induced liquid-liquid phase separation droplets in vitro and signal-induced puncta in vivo. Thermal and chemical denaturation studies of truncated NEMO variants indicate that the IVD, while not intrinsically destabilizing, can reduce the stability of surrounding regions of NEMO, due to the conflicting structural demands imparted on this region by flanking upstream and downstream domains. This conformational strain in the IVD mediates allosteric communication between N- and C-terminal regions of NEMO. Overall, these results support a model in which the IVD of NEMO participates in signal-induced activation of the IKK/NF-κB pathway by acting as a mediator of conformational changes in NEMO.
Collapse
Affiliation(s)
| | | | - Judy Wong
- Department of Biology, Boston University, Boston, MA 02215, USA
| | | | - Adrian Whitty
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Karen N. Allen
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | | |
Collapse
|
7
|
Phelan T, Lawler C, Pichlmair A, Little MA, Bowie AG, Brady G. Molluscum Contagiosum Virus Protein MC008 Targets NF-κB Activation by Inhibiting Ubiquitination of NEMO. J Virol 2023; 97:e0010823. [PMID: 36916940 PMCID: PMC10062130 DOI: 10.1128/jvi.00108-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 02/17/2023] [Indexed: 03/16/2023] Open
Abstract
Molluscum contagiosum virus (MCV) is a human-adapted poxvirus that causes a common and persistent yet mild infection characterized by distinct, contagious, papular skin lesions. These lesions are notable for having little or no inflammation associated with them and can persist for long periods without an effective clearance response from the host. Like all poxviruses, MCV encodes potent immunosuppressive proteins that perturb innate immune pathways involved in virus sensing, the interferon response, and inflammation, which collectively orchestrate antiviral immunity and clearance, with several of these pathways converging at common signaling nodes. One such node is the regulator of canonical nuclear factor kappa B (NF-κB) activation, NF-κB essential modulator (NEMO). Here, we report that the MCV protein MC008 specifically inhibits NF-κB through its interaction with NEMO, disrupting its early ubiquitin-mediated activation and subsequent downstream signaling. MC008 is the third NEMO-targeting inhibitor to be described in MCV to date, with each inhibiting NEMO activation in distinct ways, highlighting strong selective pressure to evolve multiple ways of disabling this key signaling protein. IMPORTANCE Inflammation lies at the heart of most human diseases. Understanding the pathways that drive this response is the key to new anti-inflammatory therapies. Viruses evolve to target inflammation; thus, understanding how they do this reveals how inflammation is controlled and, potentially, how to disable it when it drives disease. Molluscum contagiosum virus (MCV) has specifically evolved to infect humans and displays an unprecedented ability to suppress inflammation in our tissue. We have identified a novel inhibitor of human innate signaling from MCV, MC008, which targets NEMO, a core regulator of proinflammatory signaling. Furthermore, MC008 appears to inhibit early ubiquitination, thus interrupting later events in NEMO activation, thereby validating current models of IκB kinase (IKK) complex regulation.
Collapse
Affiliation(s)
- Thomas Phelan
- Trinity Health Kidney Centre, Trinity Translational Medicine Institute, Trinity College Dublin, St. James’ Hospital Campus, Dublin, Ireland
| | - Clara Lawler
- Trinity Health Kidney Centre, Trinity Translational Medicine Institute, Trinity College Dublin, St. James’ Hospital Campus, Dublin, Ireland
| | | | - Mark A. Little
- Trinity Health Kidney Centre, Trinity Translational Medicine Institute, Trinity College Dublin, St. James’ Hospital Campus, Dublin, Ireland
| | - Andrew G. Bowie
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Gareth Brady
- Trinity Health Kidney Centre, Trinity Translational Medicine Institute, Trinity College Dublin, St. James’ Hospital Campus, Dublin, Ireland
| |
Collapse
|
8
|
Identification of ester-linked ubiquitylation sites during TLR7 signalling increases the number of inter-ubiquitin linkages from 8 to 12. Biochem J 2022; 479:2419-2431. [PMID: 36408944 PMCID: PMC9788571 DOI: 10.1042/bcj20220510] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 11/22/2022]
Abstract
The E3 ligase HOIL-1 forms ester bonds in vitro between ubiquitin and serine/threonine residues in proteins. Here, we exploit UbiSite technology to identify serine and threonine residues undergoing HOIL-1 catalysed ubiquitylation in macrophages stimulated with R848, an activator of the TLR7/8 heterodimer. We identify Thr12, Thr14, Ser20 and Thr22 of ubiquitin as amino acid residues forming ester bonds with the C-terminal carboxylate of another ubiquitin molecule. This increases from 8 to 12 the number of ubiquitin linkage types that are formed in cells. We also identify Ser175 of IRAK4, Ser136, Thr163 and Ser168 of IRAK2 and Thr141 of MyD88 as further sites of HOIL-1-catalysed ubiquitylation together with lysine residues in these proteins that also undergo R848-dependent ubiquitylation. These findings establish that the ubiquitin chains attached to components of myddosomes are initiated by both ester and isopeptide bonds. Ester bond formation takes place within the proline, serine, threonine-rich (PST) domains of IRAK2 and IRAK4 and the intermediate domain of MyD88. The ubiquitin molecules attached to Lys162, Thr163 and Ser168 of IRAK2 are attached to different IRAK2 molecules.
Collapse
|
9
|
DiRusso CJ, Dashtiahangar M, Gilmore TD. Scaffold proteins as dynamic integrators of biological processes. J Biol Chem 2022; 298:102628. [PMID: 36273588 PMCID: PMC9672449 DOI: 10.1016/j.jbc.2022.102628] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/15/2022] Open
Abstract
Scaffold proteins act as molecular hubs for the docking of multiple proteins to organize efficient functional units for signaling cascades. Over 300 human proteins have been characterized as scaffolds, acting in a variety of signaling pathways. While the term scaffold implies a static, supportive platform, it is now clear that scaffolds are not simply inert docking stations but can undergo conformational changes that affect their dependent signaling pathways. In this review, we catalog scaffold proteins that have been shown to undergo actionable conformational changes, with a focus on the role that conformational change plays in the activity of the classic yeast scaffold STE5, as well as three human scaffold proteins (KSR, NEMO, SHANK3) that are integral to well-known signaling pathways (RAS, NF-κB, postsynaptic density). We also discuss scaffold protein conformational changes vis-à-vis liquid-liquid phase separation. Changes in scaffold structure have also been implicated in human disease, and we discuss how aberrant conformational changes may be involved in disease-related dysregulation of scaffold and signaling functions. Finally, we discuss how understanding these conformational dynamics will provide insight into the flexibility of signaling cascades and may enhance our ability to treat scaffold-associated diseases.
Collapse
|
10
|
Kelsall IR. Non-lysine ubiquitylation: Doing things differently. Front Mol Biosci 2022; 9:1008175. [PMID: 36200073 PMCID: PMC9527308 DOI: 10.3389/fmolb.2022.1008175] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/01/2022] [Indexed: 11/23/2022] Open
Abstract
The post-translational modification of proteins with ubiquitin plays a central role in nearly all aspects of eukaryotic biology. Historically, studies have focused on the conjugation of ubiquitin to lysine residues in substrates, but it is now clear that ubiquitylation can also occur on cysteine, serine, and threonine residues, as well as on the N-terminal amino group of proteins. Paradigm-shifting reports of non-proteinaceous substrates have further extended the reach of ubiquitylation beyond the proteome to include intracellular lipids and sugars. Additionally, results from bacteria have revealed novel ways to ubiquitylate (and deubiquitylate) substrates without the need for any of the enzymatic components of the canonical ubiquitylation cascade. Focusing mainly upon recent findings, this review aims to outline the current understanding of non-lysine ubiquitylation and speculate upon the molecular mechanisms and physiological importance of this non-canonical modification.
Collapse
|
11
|
Bagnéris C, Senthil Kumar SL, Baratchian M, Britt HM, Assafa TE, Thalassinos K, Collins MK, Barrett TE. Mechanistic insights into the activation of the IKK kinase complex by the Kaposi's Sarcoma Herpes virus oncoprotein vFLIP. J Biol Chem 2022; 298:102012. [PMID: 35525271 PMCID: PMC9163697 DOI: 10.1016/j.jbc.2022.102012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 11/23/2022] Open
Abstract
Constitutive activation of the canonical NF-κB signaling pathway is a major factor in Kaposi’s sarcoma-associated herpes virus pathogenesis where it is essential for the survival of primary effusion lymphoma. Central to this process is persistent upregulation of the inhibitor of κB kinase (IKK) complex by the virally encoded oncoprotein vFLIP. Although the physical interaction between vFLIP and the IKK kinase regulatory component essential for persistent activation, IKKγ, has been well characterized, it remains unclear how the kinase subunits are rendered active mechanistically. Using a combination of cell-based assays, biophysical techniques, and structural biology, we demonstrate here that vFLIP alone is sufficient to activate the IKK kinase complex. Furthermore, we identify weakly stabilized, high molecular weight vFLIP–IKKγ assemblies that are key to the activation process. Taken together, our results are the first to reveal that vFLIP-induced NF-κB activation pivots on the formation of structurally specific vFLIP–IKKγ multimers which have an important role in rendering the kinase subunits active through a process of autophosphorylation. This mechanism of NF-κB activation is in contrast to those utilized by endogenous cytokines and cellular FLIP homologues.
Collapse
Affiliation(s)
- Claire Bagnéris
- Department of Biological Sciences, Institute of Structural Molecular Biology, Birkbeck College, London, UK
| | - Swathi L Senthil Kumar
- Department of Biological Sciences, Institute of Structural Molecular Biology, Birkbeck College, London, UK
| | - Mehdi Baratchian
- Genitourinary Malignancies Research Center, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Hannah M Britt
- Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, UK
| | - Tufa E Assafa
- Chemistry and Biochemistry Department, University of California Santa Cruz, Santa Cruz, California, USA
| | - Konstantinos Thalassinos
- Department of Biological Sciences, Institute of Structural Molecular Biology, Birkbeck College, London, UK; Division of Biosciences, Institute of Structural and Molecular Biology, University College London, London, UK
| | - Mary K Collins
- Okinawa Institute of Science and Technology, Graduate University, Onna-son, Okinawa, Japan
| | - Tracey E Barrett
- Department of Biological Sciences, Institute of Structural Molecular Biology, Birkbeck College, London, UK.
| |
Collapse
|
12
|
Ko MS, Cohen SN, Polley S, Mahata SK, Biswas T, Huxford T, Ghosh G. Regulatory subunit NEMO promotes polyubiquitin-dependent induction of NF-κB through a targetable second interaction with upstream activator IKK2. J Biol Chem 2022; 298:101864. [PMID: 35339487 PMCID: PMC9035715 DOI: 10.1016/j.jbc.2022.101864] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 02/21/2022] [Accepted: 02/24/2022] [Indexed: 01/16/2023] Open
Abstract
Canonical NF-κB signaling through the inhibitor of κB kinase (IKK) complex requires induction of IKK2/IKKβ subunit catalytic activity via specific phosphorylation within its activation loop. This process is known to be dependent upon the accessory ubiquitin (Ub)-binding subunit NF-κB essential modulator (NEMO)/IKKγ as well as poly-Ub chains. However, the mechanism through which poly-Ub binding serves to promote IKK catalytic activity is unclear. Here, we show that binding of NEMO/IKKγ to linear poly-Ub promotes a second interaction between NEMO/IKKγ and IKK2/IKKβ, distinct from the well-characterized interaction of the NEMO/IKKγ N terminus to the "NEMO-binding domain" at the C terminus of IKK2/IKKβ. We mapped the location of this second interaction to a stretch of roughly six amino acids immediately N-terminal to the zinc finger domain in human NEMO/IKKγ. We also showed that amino acid residues within this region of NEMO/IKKγ are necessary for binding to IKK2/IKKβ through this secondary interaction in vitro and for full activation of IKK2/IKKβ in cultured cells. Furthermore, we identified a docking site for this segment of NEMO/IKKγ on IKK2/IKKβ within its scaffold-dimerization domain proximal to the kinase domain-Ub-like domain. Finally, we showed that a peptide derived from this region of NEMO/IKKγ is capable of interfering specifically with canonical NF-κB signaling in transfected cells. These in vitro biochemical and cell culture-based experiments suggest that, as a consequence of its association with linear poly-Ub, NEMO/IKKγ plays a direct role in priming IKK2/IKKβ for phosphorylation and that this process can be inhibited to specifically disrupt canonical NF-κB signaling.
Collapse
Affiliation(s)
- Myung Soo Ko
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California, USA; Structural Biochemistry Laboratory, Department of Chemistry & Biochemistry, San Diego State University, San Diego, California, USA
| | - Samantha N Cohen
- Structural Biochemistry Laboratory, Department of Chemistry & Biochemistry, San Diego State University, San Diego, California, USA
| | - Smarajit Polley
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California, USA
| | - Sushil K Mahata
- Department of Medicine, University of California, San Diego, La Jolla, California, USA; Medicine, VA San Diego Health Care System, San Diego, California, USA
| | - Tapan Biswas
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California, USA
| | - Tom Huxford
- Structural Biochemistry Laboratory, Department of Chemistry & Biochemistry, San Diego State University, San Diego, California, USA
| | - Gourisankar Ghosh
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, California, USA.
| |
Collapse
|
13
|
Hou XN, Sekiyama N, Ohtani Y, Yang F, Miyanoiri Y, Akagi KI, Su XC, Tochio H. Conformational Space Sampled by Domain Reorientation of Linear Diubiquitin Reflected in Its Binding Mode for Target Proteins. Chemphyschem 2021; 22:1505-1517. [PMID: 33928740 DOI: 10.1002/cphc.202100187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/28/2021] [Indexed: 11/06/2022]
Abstract
Linear polyubiquitin chains regulate diverse signaling proteins, in which the chains adopt various conformations to recognize different target proteins. Thus, the structural plasticity of the chains plays an important role in controlling the binding events. Herein, paramagnetic NMR spectroscopy is employed to explore the conformational space sampled by linear diubiquitin, a minimal unit of linear polyubiquitin, in its free state. Rigorous analysis of the data suggests that, regarding the relative positions of the ubiquitin units, particular regions of conformational space are preferentially sampled by the molecule. By combining these results with further data collected for charge-reversal derivatives of linear diubiquitin, structural insights into the factors underlying the binding events of linear diubiquitin are obtained.
Collapse
Affiliation(s)
- Xue-Ni Hou
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Naotaka Sekiyama
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Yasuko Ohtani
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Feng Yang
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, No.94 Weijin Road, Nankai District, Tianjin, 300071, P. R. China
| | - Yohei Miyanoiri
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Ken-Ichi Akagi
- NIBIOHN, Section of Laboratory Equipment, Osaka, 567-0085, Japan.,RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Xun-Cheng Su
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, No.94 Weijin Road, Nankai District, Tianjin, 300071, P. R. China
| | - Hidehito Tochio
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| |
Collapse
|
14
|
Petrova T, Zhang J, Nanda SK, Figueras-Vadillo C, Cohen P. HOIL-1-catalysed ester-linked ubiquitylation restricts IL-18 signaling in cytotoxic T cells but promotes TLR signalling in macrophages. FEBS J 2021; 288:5909-5924. [PMID: 33932090 DOI: 10.1111/febs.15896] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/19/2021] [Accepted: 04/19/2021] [Indexed: 12/27/2022]
Abstract
The atypical E3 ligase HOIL-1 forms ester bonds between ubiquitin and serine/threonine residues in proteins, but the physiological roles of this unusual modification are unknown. We now report that IL-18 signalling leading to the production of interferon γ (IFNγ) and granulocyte-macrophage colony-stimulating factor (GM-CSF) is enhanced in cytotoxic T cells from knock-in mice expressing the E3 ligase-inactive HOIL-1[C458S] mutant, demonstrating that the formation of HOIL-1-catalysed ester-linked ubiquitin bonds restricts the activation of this pathway. We show that the interaction of IRAK2 with TRAF6 is required for IL-18-stimulated IFN-γ and GM-CSF production, and that the increased production of these cytokines in cytotoxic T cells from HOIL-1[C458S] mice correlates with an increase in both the number and size of the Lys63/Met1-linked hybrid ubiquitin chains attached to IRAK2 in these cells. In contrast, the secretion of IL-12 and IL-6 and the formation of il-12 and il-6 mRNA induced in bone marrow-derived macrophages (BMDMs) by prolonged stimulation with TLR-activating ligands that signal via myddosomes, which also requires the interaction of IRAK2 with TRAF6, were not increased but modestly reduced in HOIL-1[C458S] BMDM. The decreased production of these cytokines correlated with reduced ubiquitylation of IRAK2. Our results establish that changes in HOIL-1-catalysed ester-linked ubiquitylation can promote or reduce cytokine production depending on the ligand, receptor and immune cell and may be explained by differences in the ubiquitylation of IRAK2.
Collapse
Affiliation(s)
- Tsvetana Petrova
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life sciences, University of Dundee, UK
| | - Jiazhen Zhang
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life sciences, University of Dundee, UK
| | - Sambit K Nanda
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life sciences, University of Dundee, UK
| | - Clara Figueras-Vadillo
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life sciences, University of Dundee, UK
| | - Philip Cohen
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life sciences, University of Dundee, UK
| |
Collapse
|
15
|
Jahan AS, Elbæk CR, Damgaard RB. Met1-linked ubiquitin signalling in health and disease: inflammation, immunity, cancer, and beyond. Cell Death Differ 2021; 28:473-492. [PMID: 33441937 DOI: 10.1038/s41418-020-00676-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/05/2020] [Accepted: 11/05/2020] [Indexed: 12/22/2022] Open
Abstract
Post-translational modification of proteins with ubiquitin (ubiquitination) provides a rapid and versatile mechanism for regulating cellular signalling systems. Met1-linked (or 'linear') ubiquitin chains have emerged as a key regulatory signal that controls cell death, immune signalling, and other vital cellular functions. The molecular machinery that assembles, senses, and disassembles Met1-linked ubiquitin chains is highly specific. In recent years, the thorough biochemical and genetic characterisation of the enzymes and proteins of the Met1-linked ubiquitin signalling machinery has paved the way for substantial advances in our understanding of how Met1-linked ubiquitin chains control cell signalling and biology. Here, we review current knowledge and recent insights into the role of Met1-linked ubiquitin chains in cell signalling with an emphasis on their role in disease biology. Met1-linked ubiquitin has potent regulatory functions in immune signalling, NF-κB transcription factor activation, and cell death. Importantly, mounting evidence shows that dysregulation of Met1-linked ubiquitin signalling is associated with multiple human diseases, including immune disorders, cancer, and neurodegeneration. We discuss the latest evidence on the cellular function of Met1-linked ubiquitin in the context of its associated diseases and highlight new emerging roles of Met1-linked ubiquitin chains in cell signalling, including regulation of protein quality control and metabolism.
Collapse
Affiliation(s)
- Akhee Sabiha Jahan
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs, Lyngby, Denmark
| | - Camilla Reiter Elbæk
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs, Lyngby, Denmark
| | - Rune Busk Damgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs, Lyngby, Denmark.
| |
Collapse
|
16
|
Jussupow A, Messias AC, Stehle R, Geerlof A, Solbak SMØ, Paissoni C, Bach A, Sattler M, Camilloni C. The dynamics of linear polyubiquitin. SCIENCE ADVANCES 2020; 6:6/42/eabc3786. [PMID: 33055165 PMCID: PMC7556843 DOI: 10.1126/sciadv.abc3786] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/25/2020] [Indexed: 05/17/2023]
Abstract
Polyubiquitin chains are flexible multidomain proteins, whose conformational dynamics enable them to regulate multiple biological pathways. Their dynamic is determined by the linkage between ubiquitins and by the number of ubiquitin units. Characterizing polyubiquitin behavior as a function of their length is hampered because of increasing system size and conformational variability. Here, we introduce a new approach to efficiently integrating small-angle x-ray scattering with simulations allowing us to accurately characterize the dynamics of linear di-, tri-, and tetraubiquitin in the free state as well as of diubiquitin in complex with NEMO, a central regulator in the NF-κB pathway. Our results show that the behavior of the diubiquitin subunits is independent of the presence of additional ubiquitin modules and that the dynamics of polyubiquitins with different lengths follow a simple model. Together with experimental data from multiple biophysical techniques, we then rationalize the 2:1 NEMO:polyubiquitin binding.
Collapse
Affiliation(s)
- Alexander Jussupow
- Department of Chemistry and Institute for Advanced Study, Technical University of Munich, Garching 85747, Germany
| | - Ana C Messias
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
- Center for Integrated Protein Science Munich at Department of Chemistry, Technical University of Munich, Garching 85747, Germany
| | - Ralf Stehle
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
- Center for Integrated Protein Science Munich at Department of Chemistry, Technical University of Munich, Garching 85747, Germany
| | - Arie Geerlof
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
- Center for Integrated Protein Science Munich at Department of Chemistry, Technical University of Munich, Garching 85747, Germany
| | - Sara M Ø Solbak
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Cristina Paissoni
- Dipartimento di Bioscienze, Università degli studi di Milano, 20133 Milano, Italy
| | - Anders Bach
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany.
- Center for Integrated Protein Science Munich at Department of Chemistry, Technical University of Munich, Garching 85747, Germany
| | - Carlo Camilloni
- Department of Chemistry and Institute for Advanced Study, Technical University of Munich, Garching 85747, Germany.
- Dipartimento di Bioscienze, Università degli studi di Milano, 20133 Milano, Italy
| |
Collapse
|
17
|
Ko MS, Biswas T, Mulero MC, Bobkov AA, Ghosh G, Huxford T. Structurally plastic NEMO and oligomerization prone IKK2 subunits define the behavior of human IKK2:NEMO complexes in solution. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140526. [PMID: 32853772 DOI: 10.1016/j.bbapap.2020.140526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 07/30/2020] [Accepted: 08/08/2020] [Indexed: 10/23/2022]
Abstract
The human IκB Kinase (IKK) is a multisubunit protein complex of two kinases and one scaffolding subunit that controls induction of transcription factor NF-κB activity. IKK behaves as an entity of aberrantly high apparent molecular weight in solution. Recent X-ray crystallographic and cryo-electron microscopy structures of individual catalytic subunits (IKK1/IKKα and IKK2/IKKβ) reveal that they are both stably folded dimeric proteins that engage in extensive homo-oligomerization through unique surfaces that are required for activation of their respective catalytic activities. The NEMO/IKKγ subunit is a predominantly coiled coil protein that is required for activation of IKK through the canonical NF-κB signaling pathway. Here we report size-exclusion chromatography, multi-angle light scattering, analytical centrifugation, and thermal denaturation analyses of full-length human recombinant NEMO as well as deletion and disease-linked variants. We observe that NEMO is predominantly a dimer in solution, although by virtue of its modular coiled coil regions NEMO exhibits complicated solution dynamics involving portions that are mutually antagonistic toward homodimerization. This behavior causes NEMO to behave as a significantly larger sized particle in solution. Analyses of NEMO in complex with IKK2 indicate that NEMO preserves this structurally dynamic character within the multisubuit complex and provides the complex-bound IKK2 further propensity toward homo-oligomerization. These observations provide critical information on the structural plasticity of NEMO subunit dimers which helps clarify its role in diseases and in IKK regulation through oligomerization-dependent phosphorylation of catalytic IKK2 subunit dimers.
Collapse
Affiliation(s)
- Myung Soo Ko
- Structural Biochemistry Laboratory, Department of Chemistry & Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1030, United States; Department of Chemistry & Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0357, United States
| | - Tapan Biswas
- Department of Chemistry & Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0357, United States
| | | | - Andrey A Bobkov
- Sanford Burnham Prebys Medical Discovery Institute, United States
| | - Gourisankar Ghosh
- Department of Chemistry & Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0357, United States.
| | - Tom Huxford
- Structural Biochemistry Laboratory, Department of Chemistry & Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1030, United States.
| |
Collapse
|
18
|
Abstract
The ubiquitylation of NF-κB essential modulator (NEMO) is part of the intracellular immune signalling pathway. Monoubiquitylated NEMO is required for exploring the mechanism of NEMO linear ubiquitylation by LUBAC (linear ubiquitin chain assembly complex), but is not accessible by biological techniques. Here we perform the chemical ubiquitylation of NEMO using a ligation auxiliary, which only requires a two-step synthesis, and is easily installed onto the lysine side-chain. Chemical ligation occurs directly on the lysine ε amine and remains efficient below pH 7. We show that ubiquitylated NEMO has similar affinity to linear diubiquitin chains as unmodified NEMO. The proximal ubiquitin of chemically synthesised NEMOCoZi-Ub is accepted as a substrate for linear extension by the (RING-Between-RING) RBR domain of HOIL-1-interacting protein (HOIP) alone. Our results indicate that NEMO linear ubiquitylation consists of two-steps, an initial priming event and a separate extension step requiring different LUBAC components.
Collapse
|
19
|
Li L, Tang P, Zhou Z, Wang Q, Xu T, Zhao S, Huang Y, Kong F, Liu W, Cheng L, Zhou Z, Zhao X, Gu C, Luo Y, Tao G, Qian D, Chen J, Fan J, Yin G. GIT1 regulates angiogenic factor secretion in bone marrow mesenchymal stem cells via NF-κB/Notch signalling to promote angiogenesis. Cell Prolif 2019; 52:e12689. [PMID: 31502302 PMCID: PMC6869488 DOI: 10.1111/cpr.12689] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/23/2019] [Accepted: 08/11/2019] [Indexed: 12/24/2022] Open
Abstract
Objectives Osteogenesis is coupled with angiogenesis during bone remodelling. G‐protein‐coupled receptor (GPCR) kinase 2‐interacting protein‐1 (GIT1) is an important protein that participates in fracture healing by regulating angiogenesis. This study investigated whether GIT1 could affect bone mesenchymal stem cells (BMSCs) to secrete angiogenic factors to enhance fracture healing by promoting angiogenesis and its possible mechanism. Materials and methods The angiogenesis of mice post‐fracture was detected by micro‐CT and immunofluorescence. Subsequently, vascular endothelial growth factor (VEGF) level in mouse and human BMSCs (hBMSCs) under TNF‐α stimulation was detected. The hBMSCs were transfected with GIT1 shRNAs to further explore the relationship between GIT1 and VEGF and angiogenesis in vitro. Furthermore, based on previous research on GIT1, possible signal pathways were investigated. Results GIT1 knockout mice exhibited impaired angiogenesis and delayed fracture healing. And GIT1 deficiency remarkably reduced the expression of VEGF mRNA in BMSCs, which affected the proliferation and migration of human umbilical vein endothelial cells. GIT1 knockdown inhibited the activation of Notch and NF‐κB signals by decreasing nuclear transportation of NICD and P65/P50, respectively. Overexpression of the canonical NF‐κB subunits P65 and P50 markedly increased NICD‐dependent activation of recombination signal‐binding protein‐jκ reporter. Finally, GIT1 enhanced the affinity of NF‐κB essential modulator (NEMO) for K63‐linked ubiquitin chains via interaction with NEMO coiled‐coil 2 domains. Conclusion These data revealed a positive role for GIT1 by modulating the Notch/NF‐κB signals which promoting paracrine of BMSCs to enhance angiogenesis and fracture healing.
Collapse
Affiliation(s)
- Linwei Li
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Pengyu Tang
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zheng Zhou
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Qian Wang
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Tao Xu
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Shujie Zhao
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yifan Huang
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Fanqi Kong
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Liu
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Lin Cheng
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zhimin Zhou
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xuan Zhao
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Changjiang Gu
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yongjun Luo
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Gaojian Tao
- Department of Pain, Affiliated Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China
| | - Dingfei Qian
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jian Chen
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jin Fan
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Guoyong Yin
- Department of Orthopedic, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| |
Collapse
|
20
|
Shaffer R, DeMaria AM, Kagermazova L, Liu Y, Babaei M, Caban-Penix S, Cervantes A, Jehle S, Makowski L, Gilmore TD, Whitty A, Allen KN. A Central Region of NF-κB Essential Modulator Is Required for IKKβ-Induced Conformational Change and for Signal Propagation. Biochemistry 2019; 58:2906-2920. [PMID: 31145594 DOI: 10.1021/acs.biochem.8b01316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
NF-κB essential modulator (NEMO) regulates NF-κB signaling by acting as a scaffold for the kinase IKKβ to direct its activity toward the NF-κB inhibitor, IκBα. Here, we show that a highly conserved central region of NEMO termed the intervening domain (IVD, amino acids 112-195) plays a key role in NEMO function. We determined a structural model of full-length NEMO by small-angle X-ray scattering and show that full-length, wild-type NEMO becomes more compact upon binding of a peptide comprising the NEMO binding domain of IKKβ (amino acids 701-745). Mutation of conserved IVD residues (9SG-NEMO) disrupts this conformational change in NEMO and abolishes the ability of NEMO to propagate NF-κB signaling in cells, although the affinity of 9SG-NEMO for IKKβ compared to that of the wild type is unchanged. On the basis of these results, we propose a model in which the IVD is required for a conformational change in NEMO that is necessary for its ability to direct phosphorylation of IκBα by IKKβ. Our findings suggest a molecular explanation for certain disease-associated mutations within the IVD and provide insight into the role of conformational change in signaling scaffold proteins.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Lee Makowski
- Department of Bioengineering , Northeastern University , Boston , Massachusetts 02115 , United States
| | | | | | | |
Collapse
|
21
|
Shi JH, Sun SC. Tumor Necrosis Factor Receptor-Associated Factor Regulation of Nuclear Factor κB and Mitogen-Activated Protein Kinase Pathways. Front Immunol 2018; 9:1849. [PMID: 30140268 PMCID: PMC6094638 DOI: 10.3389/fimmu.2018.01849] [Citation(s) in RCA: 214] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 07/26/2018] [Indexed: 01/09/2023] Open
Abstract
Tumor necrosis factor receptor (TNFR)-associated factors (TRAFs) are a family of structurally related proteins that transduces signals from members of TNFR superfamily and various other immune receptors. Major downstream signaling events mediated by the TRAF molecules include activation of the transcription factor nuclear factor κB (NF-κB) and the mitogen-activated protein kinases (MAPKs). In addition, some TRAF family members, particularly TRAF2 and TRAF3, serve as negative regulators of specific signaling pathways, such as the noncanonical NF-κB and proinflammatory toll-like receptor pathways. Thus, TRAFs possess important and complex signaling functions in the immune system and play an important role in regulating immune and inflammatory responses. This review will focus on the role of TRAF proteins in the regulation of NF-κB and MAPK signaling pathways.
Collapse
Affiliation(s)
- Jian-Hong Shi
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding, China
| | - Shao-Cong Sun
- Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| |
Collapse
|
22
|
Abstract
This review by Shan et al. discusses necroptosis, a form of regulated necrotic cell death mediated by RIPK1 kinase activity, RIPK3, and MLKL, which can be activated under apoptosis-deficient conditions. Both necroptosis and apoptosis can be activated in response to various mutations that result in the abortion of defective embryos and during human inflammatory and neurodegenerative pathologies. Necroptosis, a form of regulated necrotic cell death mediated by RIPK1 (receptor-interacting protein kinase 1) kinase activity, RIPK3, and MLKL (mixed-lineage kinase domain-like pseudokinase), can be activated under apoptosis-deficient conditions. Modulating the activation of RIPK1 by ubiquitination and phosphorylation is critical to control both necroptosis and apoptosis. Mutant mice with kinase-dead RIPK1 or RIPK3 and MLKL deficiency show no detrimental phenotype in regard to development and adult homeostasis. However, necroptosis and apoptosis can be activated in response to various mutations that result in the abortion of the defective embryos and human inflammatory and neurodegenerative pathologies. RIPK1 inhibition represents a key therapeutic strategy for treatment of diseases where blocking both necroptosis and apoptosis can be beneficial.
Collapse
Affiliation(s)
- Bing Shan
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, PuDong District, Shanghai 201203, China
| | - Heling Pan
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, PuDong District, Shanghai 201203, China
| | - Ayaz Najafov
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Junying Yuan
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, PuDong District, Shanghai 201203, China.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| |
Collapse
|
23
|
Tang Q, Chakraborty S, Xu G. Mechanism of vaccinia viral protein B14-mediated inhibition of IκB kinase β activation. J Biol Chem 2018; 293:10344-10352. [PMID: 29748387 PMCID: PMC6028965 DOI: 10.1074/jbc.ra118.002817] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 05/03/2018] [Indexed: 11/28/2022] Open
Abstract
Activation of IκB kinase β (IKKβ) is a central event in the NF-κB–mediated canonical pro-inflammatory pathway. Numerous studies have reported that oligomerization-mediated trans autophosphorylation of IKKβ is indispensable for its phosphorylation, leading to its activation and IKKβ-mediated phosphorylation of substrates such as IκB proteins. Moreover, IKKβ's interaction with the NF-κB essential modifier (NEMO) is necessary for IKKβ activation. Interestingly, some viruses encode virulence factors that target IKKβ to inhibit NF-κB–mediated antiviral immune responses. One of these factors is the vaccinia viral protein B14, which directly interacts with and inhibits IKKβ. Here we mapped the interaction interface on the B14 and IKKβ proteins. We observed that B14 binds to the junction of the kinase domain (KD) and scaffold and dimerization domain (SDD) of IKKβ. Molecular docking analyses identified key interface residues in both IKKβ and B14 that were further confirmed by mutational studies to promote binding of the two proteins. During trans autophosphorylation of protein kinases in the IKK complex, the activation segments of neighboring kinases need to transiently interact with each other's active sites, and we found that the B14–IKKβ interaction sterically hinders direct contact between the kinase domains of IKKβ in the IKK complex, containing IKKβ, IKKα, and NEMO in human cells. We conclude that binding of B14 to IKKβ prevents IKKβ trans autophosphorylation and activation, thereby inhibiting NF-κB signaling. Our study provides critical structural and mechanistic information for the design of potential therapeutic agents to target IKKβ activation for the management of inflammatory disorders.
Collapse
Affiliation(s)
- Qingyu Tang
- From the Department of Molecular and Structural Biochemistry, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - Sayan Chakraborty
- From the Department of Molecular and Structural Biochemistry, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - Guozhou Xu
- From the Department of Molecular and Structural Biochemistry, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, North Carolina 27695
| |
Collapse
|
24
|
Fennell LM, Rahighi S, Ikeda F. Linear ubiquitin chain-binding domains. FEBS J 2018; 285:2746-2761. [PMID: 29679476 DOI: 10.1111/febs.14478] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 03/08/2018] [Accepted: 04/13/2018] [Indexed: 12/25/2022]
Abstract
Ubiquitin modification (ubiquitination) of target proteins can vary with respect to chain lengths, linkage type, and chain forms, such as homologous, mixed, and branched ubiquitin chains. Thus, ubiquitination can generate multiple unique surfaces on a target protein substrate. Ubiquitin-binding domains (UBDs) recognize ubiquitinated substrates, by specifically binding to these unique surfaces, modulate the formation of cellular signaling complexes and regulate downstream signaling cascades. Among the eight different homotypic chain types, Met1-linked (also termed linear) chains are the only chains in which linkage occurs on a non-Lys residue of ubiquitin. Linear ubiquitin chains have been implicated in immune responses, cell death and autophagy, and several UBDs - specific for linear ubiquitin chains - have been identified. In this review, we describe the main principles of ubiquitin recognition by UBDs, focusing on linear ubiquitin chains and their roles in biology.
Collapse
Affiliation(s)
- Lilian M Fennell
- Institute of Molecular Biotechnology (IMBA), Vienna Biocenter (VBC), Austria
| | - Simin Rahighi
- Chapman University School of Pharmacy (CUSP), Harry and Diane Health Science Campus, Chapman University, Irvine, CA, USA
| | - Fumiyo Ikeda
- Institute of Molecular Biotechnology (IMBA), Vienna Biocenter (VBC), Austria
| |
Collapse
|
25
|
Höhfeld J, Hoppe T. Ub and Down: Ubiquitin Exercise for the Elderly. Trends Cell Biol 2018; 28:512-522. [PMID: 29704981 DOI: 10.1016/j.tcb.2018.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 03/20/2018] [Accepted: 03/21/2018] [Indexed: 11/29/2022]
Abstract
Conjugation of ubiquitin onto proteins generates a degradation signal or exerts degradation-independent regulatory functions. Ubiquitylation is governed by the antagonistic action of ubiquitin ligases and deubiquitylating enzymes (DUBs). Several recent publications illustrate a balanced interplay of ligases and DUBs at signaling hubs that are central to longevity and protein homeostasis (proteostasis). In addition, stress-induced alterations of ubiquitin conjugation are emerging as key events that drive aging and contribute to the pathology of age-related diseases. This physiological role of dynamic ubiquitylation further extends its well-known function in protein regulation and quality control at the cellular level. Recent work thus significantly advances our understanding of the aging process both at the molecular and organismal level.
Collapse
Affiliation(s)
- Jörg Höhfeld
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Strasse 61a, 53121 Bonn, Germany.
| | - Thorsten Hoppe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, 50931 Cologne, Germany.
| |
Collapse
|