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Shaffer R, DeMaria AM, Kagermazova L, Liu Y, Babaei M, 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 PMCID: PMC9295417 DOI: 10.1021/acs.biochem.8b01316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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.
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Affiliation(s)
- Robert Shaffer
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | | | | | - Yuekun Liu
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Milad Babaei
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Suhaily Penix
- Department of Biology, Boston University, Boston, MA 02215, USA
| | | | - Stefan Jehle
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Lee Makowski
- Department of Bioengineering, Northeastern University, Boston, MA 02115, USA
| | | | - Adrian Whitty
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Karen N. Allen
- Department of Chemistry, Boston University, Boston, MA 02215, USA
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Huo X, Zhang X, Yu C, Cheng E, Zhang Q, Dunbar KB, Pham TH, Lynch JP, Wang DH, Bresalier RS, Spechler SJ, Souza RF. Aspirin prevents NF-κB activation and CDX2 expression stimulated by acid and bile salts in oesophageal squamous cells of patients with Barrett's oesophagus. Gut 2018; 67:606-615. [PMID: 28442495 PMCID: PMC5656558 DOI: 10.1136/gutjnl-2016-313584] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/28/2017] [Accepted: 04/03/2017] [Indexed: 12/11/2022]
Abstract
OBJECTIVE In previous studies using oesophageal squamous cells from patients with Barrett's oesophagus (normal oesophageal squamous (NES)-B cells) and from patients without Barrett's oesophagus (NES-G cells), we showed that acid and bile salts induced caudal-related homeobox transcription factor 2 (CDX2) expression only in NES-B cells. CDX2, a transcription factor required to form intestinal epithelium, is a target of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signalling, which can be inhibited by aspirin. We explored mechanisms underlying differences between NES-B and NES-G cells in CDX2 expression and effects of aspirin on that CDX2 expression. DESIGN We exposed NES-B and NES-G cells to acid and bile salts, with and without aspirin, and evaluated effects on IκB-NF-κB-PKAc complex activation, p65 NF-κB subunit function, and CDX2 expression. RESULTS In both NES-B and NES-G cells, acid and bile salts activated nicotinamide adenine dinucleotide phosphate oxidase to generate H2O2, which activated the IκB-NF-κB-PKAc complex. NES-B cells exhibited higher levels of phosphorylated IκB and p65 and greater NF-κB transcriptional activity than NES-G cells, indicating greater IκB-NF-κB-PKAc complex activation by acid and bile salts in NES-B cells, and p65 siRNA prevented their increased expression of CDX2. Aspirin blocked IκB phosphorylation, p65 nuclear translocation, CDX2 promoter activation and CDX2 expression induced by acid and bile salts in NES-B cells. CONCLUSIONS Differences between NES-B and NES-G cells in NF-κB activation by acid and bile salts can account for their differences in CDX2 expression, and their CDX2 expression can be blocked by aspirin. These findings might explain why some patients with GORD develop Barrett's oesophagus while others do not, and why aspirin might protect against development of Barrett's oesophagus.
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Affiliation(s)
- Xiaofang Huo
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, Texas
| | - Xi Zhang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, Texas
| | - Chunhua Yu
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Edaire Cheng
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Pediatrics, Children's Medical Center and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Qiuyang Zhang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, Texas
| | - Kerry B. Dunbar
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Thai H. Pham
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Surgery, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - John P. Lynch
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David H. Wang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX
| | - Robert S. Bresalier
- Department of Medicine, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Stuart J. Spechler
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, Texas,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX
| | - Rhonda F. Souza
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, Texas,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX
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4
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Christian F, Smith EL, Carmody RJ. The Regulation of NF-κB Subunits by Phosphorylation. Cells 2016; 5:cells5010012. [PMID: 26999213 PMCID: PMC4810097 DOI: 10.3390/cells5010012] [Citation(s) in RCA: 501] [Impact Index Per Article: 62.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 03/09/2016] [Accepted: 03/14/2016] [Indexed: 12/31/2022] Open
Abstract
The NF-κB transcription factor is the master regulator of the inflammatory response and is essential for the homeostasis of the immune system. NF-κB regulates the transcription of genes that control inflammation, immune cell development, cell cycle, proliferation, and cell death. The fundamental role that NF-κB plays in key physiological processes makes it an important factor in determining health and disease. The importance of NF-κB in tissue homeostasis and immunity has frustrated therapeutic approaches aimed at inhibiting NF-κB activation. However, significant research efforts have revealed the crucial contribution of NF-κB phosphorylation to controlling NF-κB directed transactivation. Importantly, NF-κB phosphorylation controls transcription in a gene-specific manner, offering new opportunities to selectively target NF-κB for therapeutic benefit. This review will focus on the phosphorylation of the NF-κB subunits and the impact on NF-κB function.
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Affiliation(s)
- Frank Christian
- Centre for Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK.
| | - Emma L Smith
- Centre for Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK.
| | - Ruaidhrí J Carmody
- Centre for Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK.
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Perkins ND. Post-translational modifications regulating the activity and function of the nuclear factor kappa B pathway. Oncogene 2006; 25:6717-30. [PMID: 17072324 DOI: 10.1038/sj.onc.1209937] [Citation(s) in RCA: 526] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The diverse cellular and biological functions of the nuclear factor kappa B (NF-kappaB) pathway, together with the catastrophic consequences of its aberrant regulation, demand specific and highly regulated control of its activity. As described in this review, regulation of the NF-kappaB pathway is brought about through multiple post-translational modifications that control the activity of the core components of NF-kappaB signaling: the IkappaB kinase (IKK) complex, the IkappaB proteins and the NF-kappaB subunits themselves. These regulatory modifications, which include phosphorylation, ubiquitination, acetylation, sumoylation and nitrosylation, can vary, depending on the nature of the NF-kappaB-inducing stimulus. Moreover, they frequently have distinct, sometimes antagonistic, functional consequences and the same modification can have different effects depending on the context. Given the important role of NF-kappaB in human health and disease, understanding these pathways will not only provide valuable insights into mechanism and function, but could also lead to new drug targets and the development of diagnostic and prognostic biomarkers for many pathological conditions.
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Affiliation(s)
- N D Perkins
- Division of Gene Regulation and Expression, University of Dundee, Dundee, Scotland, UK.
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Abstract
Complexes formed from the nuclear factor kappaB (NF-kappaB) family of transcription factors are ubiquitously expressed and are induced by a diverse array of stimuli. This results in their becoming activated in a wide variety of different settings. While the functions of NF-kappaB in many of these contexts have been the subject of intense research and are now well established, it is also clear that there is great diversity in the effects and consequences of NF-kappaB activation. NF-kappaB subunits do not necessarily regulate the same genes, in an identical manner, in all of the different circumstances in which they are induced. This review will discuss the different functions of NF-kappaB, the pathways that modulate NF-kappaB subunit activity and, in contrast to its more commonly thought of role as a promoter of cancer cell growth and survival, the ability of NF-kappaB, under some circumstances, to behave as a tumor suppressor.
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Affiliation(s)
- N D Perkins
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, MSI/WTB Complex, Dow Street, Dundee, Scotland DD1 5EH, UK.
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