1
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Martin DDO, Sanders SS. Let's get fat: emergence of S-acylation as a therapeutic target in Huntington disease. Biochem Soc Trans 2024; 52:1385-1392. [PMID: 38695682 DOI: 10.1042/bst20231290] [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: 03/01/2024] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 06/27/2024]
Abstract
Protein mislocalization is a key initial step in neurodegeneration, regardless of etiology, and has been linked to changes in the dynamic addition of saturated fatty acids to proteins, a process known as S-acylation. With the advent of new techniques to study S-acylation and the recent discovery of new enzymes that facilitate protein deacylation, novel small molecules are emerging as potential new therapeutic treatments. Huntington disease (HD) is a devastating, fatal neurodegenerative disease characterized by motor, cognitive, and psychiatric deficits caused by a CAG repeat expansion in the HTT gene. The protein that is mutated in HD, huntingtin, is less S-acylated which is associated with mutant HTT aggregation and cytotoxicity. Recent exciting findings indicate that restoring S-acylation in HD models using small molecule inhibitors of the deacylation enzymes is protective. Herein, we set out to describe the known roles of S-acylation in HD and how it can be targeted for therapeutic design.
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Affiliation(s)
- Dale D O Martin
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Shaun S Sanders
- NeuroPalm Lab, Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
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2
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Zhang Z, Gehin C, Abriata LA, Dal Peraro M, Lashuel H. Differential Effects of Post-translational Modifications on the Membrane Interaction of Huntingtin Protein. ACS Chem Neurosci 2024; 15:2408-2419. [PMID: 38752226 PMCID: PMC11191595 DOI: 10.1021/acschemneuro.4c00091] [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: 02/07/2024] [Revised: 04/05/2024] [Accepted: 05/06/2024] [Indexed: 05/25/2024] Open
Abstract
Huntington's disease is a neurodegenerative disorder caused by an expanded polyglutamine stretch near the N-terminus of the huntingtin (HTT) protein, rendering the protein more prone to aggregate. The first 17 residues in HTT (Nt17) interact with lipid membranes and harbor multiple post-translational modifications (PTMs) that can modulate HTT conformation and aggregation. In this study, we used a combination of biophysical studies and molecular simulations to investigate the effect of PTMs on the helicity of Nt17 in the presence of various lipid membranes. We demonstrate that anionic lipids such as PI4P, PI(4,5)P2, and GM1 significantly enhance the helical structure of unmodified Nt17. This effect is attenuated by single acetylation events at K6, K9, or K15, whereas tri-acetylation at these sites abolishes Nt17-membrane interaction. Similarly, single phosphorylation at S13 and S16 decreased but did not abolish the POPG and PIP2-induced helicity, while dual phosphorylation at these sites markedly diminished Nt17 helicity, regardless of lipid composition. The helicity of Nt17 with phosphorylation at T3 is insensitive to the membrane environment. Oxidation at M8 variably affects membrane-induced helicity, highlighting a lipid-dependent modulation of the Nt17 structure. Altogether, our findings reveal differential effects of PTMs and crosstalks between PTMs on membrane interaction and conformation of HTT. Intriguingly, the effects of phosphorylation at T3 or single acetylation at K6, K9, and K15 on Nt17 conformation in the presence of certain membranes do not mirror that observed in the absence of membranes. Our studies provide novel insights into the complex relationship between Nt17 structure, PTMs, and membrane binding.
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Affiliation(s)
- Zhidian Zhang
- Laboratory
of Molecular and Chemical Biology of Neurodegeneration, School of
Life Sciences, Institute of Bioengineering,
Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
- Laboratory
for Biomolecular Modeling, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale
de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Charlotte Gehin
- Laboratory
of Molecular and Chemical Biology of Neurodegeneration, School of
Life Sciences, Institute of Bioengineering,
Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Luciano A Abriata
- Laboratory
for Biomolecular Modeling, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale
de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Matteo Dal Peraro
- Laboratory
for Biomolecular Modeling, School of Life Sciences, Institute of Bioengineering, Ecole Polytechnique Fédérale
de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Hilal Lashuel
- Laboratory
of Molecular and Chemical Biology of Neurodegeneration, School of
Life Sciences, Institute of Bioengineering,
Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
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3
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Sahu M, Rani N, Kumar P. Simulation and Computational Study of RING Domain Mutants of BRCA1 and Ube2k in AD/PD Pathophysiology. Mol Biotechnol 2024; 66:1095-1115. [PMID: 38172369 DOI: 10.1007/s12033-023-01006-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 11/27/2023] [Indexed: 01/05/2024]
Abstract
Lysine-based post-translational modification (PTM) such as acylation, acetylation, deamination, methylation, SUMOylation, and ubiquitination has proven to be a major regulator of gene expression, chromatin structure, protein stability, protein-protein interaction, protein degradation, and cellular localization. However, besides all the PTMs, ubiquitination stands as the second most common PTM after phosphorylation that is involved in the etiology of neurodegenerative diseases (NDDs) namely, Alzheimer's disease (AD) and Parkinson's disease (PD). NDDs are characterized by the accumulation of misfolded protein aggregates in the brain that lead to disease-related gene mutation and irregular protein homeostasis. The ubiquitin-proteasome system (UPS) is in charge of degrading these misfolded proteins, which involve an interplay of E1, E2, E3, and deubiquitinase enzymes. Impaired UPS has been commonly observed in NDDs and E3 ligases are the key members of the UPS, thus, dysfunction of the same can accelerate the neurodegeneration process. Therefore, the aim of this study is firstly, to find E3 ligases that are common in both AD and PD through data mining. Secondly, to study the impact of mutation on its structure and function. The study deciphered 74 E3 ligases that were common in both AD and PD. Later, 10 hub genes were calculated of which protein-protein interaction, pathway enrichment, lysine site prediction, domain, and motif analysis were performed. The results predicted BRCA1, PML, and TRIM33 as the top three putative lysine-modified E3 ligases involved in AD and PD pathogenesis. However, based on structural characterization, BRCA1 was taken further to study RING domain mutation that inferred K32Y, K32L, K32C, K45V, K45Y, and K45G as potential mutants that alter the structural and functional ability of BRCA1 to interact with Ube2k, E2-conjugating enzyme. The most probable mutant observed after molecular dynamics simulation of 50 ns is K32L. Therefore, our study concludes BRCA1, a potential E3 ligase common in AD and PD, and RING domain mutation at sites K32 and K45 possibly disturbs its interaction with its E2, Ube2k.
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Affiliation(s)
- Mehar Sahu
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Neetu Rani
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), Shahbad Daulatpur, Bawana Road, Delhi, 110042, India.
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4
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Kinger S, Jagtap YA, Kumar P, Choudhary A, Prasad A, Prajapati VK, Kumar A, Mehta G, Mishra A. Proteostasis in neurodegenerative diseases. Adv Clin Chem 2024; 121:270-333. [PMID: 38797543 DOI: 10.1016/bs.acc.2024.04.002] [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] [Indexed: 05/29/2024]
Abstract
Proteostasis is essential for normal function of proteins and vital for cellular health and survival. Proteostasis encompasses all stages in the "life" of a protein, that is, from translation to functional performance and, ultimately, to degradation. Proteins need native conformations for function and in the presence of multiple types of stress, their misfolding and aggregation can occur. A coordinated network of proteins is at the core of proteostasis in cells. Among these, chaperones are required for maintaining the integrity of protein conformations by preventing misfolding and aggregation and guide those with abnormal conformation to degradation. The ubiquitin-proteasome system (UPS) and autophagy are major cellular pathways for degrading proteins. Although failure or decreased functioning of components of this network can lead to proteotoxicity and disease, like neuron degenerative diseases, underlying factors are not completely understood. Accumulating misfolded and aggregated proteins are considered major pathomechanisms of neurodegeneration. In this chapter, we have described the components of three major branches required for proteostasis-chaperones, UPS and autophagy, the mechanistic basis of their function, and their potential for protection against various neurodegenerative conditions, like Alzheimer's, Parkinson's, and Huntington's disease. The modulation of various proteostasis network proteins, like chaperones, E3 ubiquitin ligases, proteasome, and autophagy-associated proteins as therapeutic targets by small molecules as well as new and unconventional approaches, shows promise.
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Affiliation(s)
- Sumit Kinger
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Yuvraj Anandrao Jagtap
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Prashant Kumar
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Akash Choudhary
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Amit Prasad
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Amit Kumar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, Madhya Pradesh, India
| | - Gunjan Mehta
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India.
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5
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Kim J, Byun I, Kim DY, Joh H, Kim HJ, Lee MJ. Targeted protein degradation directly engaging lysosomes or proteasomes. Chem Soc Rev 2024; 53:3253-3272. [PMID: 38369971 DOI: 10.1039/d3cs00344b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Targeted protein degradation (TPD) has been established as a viable alternative to attenuate the function of a specific protein of interest in both biological and clinical contexts. The unique TPD mode-of-action has allowed previously undruggable proteins to become feasible targets, expanding the landscape of "druggable" properties and "privileged" target proteins. As TPD continues to evolve, a range of innovative strategies, which do not depend on recruiting E3 ubiquitin ligases as in proteolysis-targeting chimeras (PROTACs), have emerged. Here, we present an overview of direct lysosome- and proteasome-engaging modalities and discuss their perspectives, advantages, and limitations. We outline the chemical composition, biochemical activity, and pharmaceutical characteristics of each degrader. These alternative TPD approaches not only complement the first generation of PROTACs for intracellular protein degradation but also offer unique strategies for targeting pathologic proteins located on the cell membrane and in the extracellular space.
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Affiliation(s)
- Jiseong Kim
- Department of Biochemistry & Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Insuk Byun
- Department of Biochemistry & Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Do Young Kim
- Department of Chemistry, College of Science, Korea University, Seoul 02841, Korea.
| | - Hyunhi Joh
- Department of Chemistry, College of Science, Korea University, Seoul 02841, Korea.
| | - Hak Joong Kim
- Department of Chemistry, College of Science, Korea University, Seoul 02841, Korea.
| | - Min Jae Lee
- Department of Biochemistry & Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
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6
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Liao D, Huang Y, Liu D, Zhang H, Shi X, Li X, Luo P. The role of s-palmitoylation in neurological diseases: implication for zDHHC family. Front Pharmacol 2024; 14:1342830. [PMID: 38293675 PMCID: PMC10824933 DOI: 10.3389/fphar.2023.1342830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 12/31/2023] [Indexed: 02/01/2024] Open
Abstract
S-palmitoylation is a reversible posttranslational modification, and the palmitoylation reaction in human-derived cells is mediated by the zDHHC family, which is composed of S-acyltransferase enzymes that possess the DHHC (Asp-His-His-Cys) structural domain. zDHHC proteins form an autoacylation intermediate, which then attaches the fatty acid to cysteine a residue in the target protein. zDHHC proteins sublocalize in different neuronal structures and exert dif-ferential effects on neurons. In humans, many zDHHC proteins are closely related to human neu-rological disor-ders. This review focuses on a variety of neurological disorders, such as AD (Alz-heimer's disease), HD (Huntington's disease), SCZ (schizophrenia), XLID (X-linked intellectual disability), attention deficit hyperactivity disorder and glioma. In this paper, we will discuss and summarize the research progress regarding the role of zDHHC proteins in these neu-rological disorders.
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Affiliation(s)
- Dan Liao
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Yutao Huang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Dan Liu
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
- School of Life Science, Northwest University, Xi’an, China
| | - Haofuzi Zhang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Xinyu Shi
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Xin Li
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi’an, China
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, China
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7
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Alshehabi Y, Martin DDO. Protective Proteolysis in Huntington's Disease: Unraveling the Role of Post-Translational Myristoylation of Huntingtin in Autophagy. J Huntingtons Dis 2024; 13:267-277. [PMID: 38995796 DOI: 10.3233/jhd-240028] [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] [Indexed: 07/14/2024]
Abstract
Huntington's disease (HD) is a devastating neurodegenerative disorder characterized by impaired motor function and cognitive decline, ultimately leading to death. HD is caused by a polyglutamine expansion in the N-terminal region of the huntingtin (HTT) protein, which is linked to decreased HTT turnover, increased HTT proteolysis, increased HTT aggregation, and subsequent neuronal death. In this review, we explore the mechanism of the protective effect of blocking HTT proteolysis at D586, which has been shown to rescue the HD phenotype in HD mouse models. Until recently, the mechanism remained unclear. Herein, we discuss how blocking HTT proteolysis at D586 promotes HTT turnover by correcting autophagy, and making HTT a better autophagy substrate, through post-translational myristoylation of HTT at G553.
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Affiliation(s)
- Yasmeen Alshehabi
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Dale D O Martin
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
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8
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Stonebraker AR, Hankin R, Kapp KL, Li P, Valentine SJ, Legleiter J. Charge within Nt17 peptides modulates huntingtin aggregation and initial lipid binding events. Biophys Chem 2023; 303:107123. [PMID: 37852163 PMCID: PMC10843285 DOI: 10.1016/j.bpc.2023.107123] [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: 06/27/2023] [Revised: 09/22/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023]
Abstract
Toxic aggregation of pathogenic huntingtin protein (htt) is implicated in Huntington's disease and influenced by various factors, including the first seventeen amino acids at the N-terminus (Nt17) and the presence of lipid membranes. Nt17 has a propensity to form an amphipathic α-helix in the presence of binding partners, which promotes α-helix rich oligomer formation and facilitates htt/lipid interactions. Within Nt17 are multiple sites that are subject to post-translational modification, including acetylation and phosphorylation. Acetylation can occur at lysine 6, 9, and/or 15 while phosphorylation can occur at threonine 3, serine 13, and/or serine 16. Such modifications impact aggregation and lipid binding through the alteration of various intra- and intermolecular interactions. When incubated with htt-exon1(46Q), free Nt17 peptides containing point mutations mimicking acetylation or phosphorylation reduced fibril formation and altered oligomer morphologies. Upon exposure to lipid vesicles, changes to peptide/lipid complexation were observed and peptide-containing oligomers demonstrated reduced lipid interactions.
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Affiliation(s)
- Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Rachel Hankin
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Kathryn L Kapp
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Peng Li
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Stephen J Valentine
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26506, USA; Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, USA; Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, WV 26505, USA.
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9
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Middleton AJ, Day CL. From seeds to trees: how E2 enzymes grow ubiquitin chains. Biochem Soc Trans 2023; 51:353-362. [PMID: 36645006 PMCID: PMC9987950 DOI: 10.1042/bst20220880] [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: 11/24/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/17/2023]
Abstract
Modification of proteins by ubiquitin is a highly regulated process that plays a critical role in eukaryotes, from the construction of signalling platforms to the control of cell division. Aberrations in ubiquitin transfer are associated with many diseases, including cancer and neurodegenerative disorders. The ubiquitin machinery generates a rich code on substrate proteins, spanning from single ubiquitin modifications to polyubiquitin chains with diverse linkage types. Central to this process are the E2 enzymes, which often determine the exact nature of the ubiquitin code. The focus of this mini-review is on the molecular details of how E2 enzymes can initiate and grow ubiquitin chains. In particular, recent developments and biochemical breakthroughs that help explain how the degradative E2 enzymes, Ube2s, Ube2k, and Ube2r, generate complex ubiquitin chains with exquisite specificity will be discussed.
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Affiliation(s)
- Adam J. Middleton
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Catherine L. Day
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
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10
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Lemarié FL, Sanders SS, Nguyen Y, Martin DDO, Hayden MR. Full-length huntingtin is palmitoylated at multiple sites and post-translationally myristoylated following caspase-cleavage. Front Physiol 2023; 14:1086112. [PMID: 36711022 PMCID: PMC9880554 DOI: 10.3389/fphys.2023.1086112] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Introduction: Huntington disease is an autosomal dominant neurodegenerative disorder which is caused by a CAG repeat expansion in the HTT gene that codes for an elongated polyglutamine tract in the huntingtin (HTT) protein. Huntingtin is subjected to multiple post-translational modifications which regulate its cellular functions and degradation. We have previously identified a palmitoylation site at cysteine 214 (C214), catalyzed by the enzymes ZDHHC17 and ZDHHC13. Reduced palmitoylation level of mutant huntingtin is linked to toxicity and loss of function. Moreover, we have described N-terminal myristoylation by the N-myristoyltransferases of a short fragment of huntingtin (HTT553-586) at glycine 553 (G553) following proteolysis at aspartate 552 (D552). Results: Here, we show that huntingtin is palmitoylated at numerous cysteines: C105, C433, C3134 and C3144. In addition, we confirm that full-length huntingtin is cleaved at D552 and post-translationally myristoylated at G553. Importantly, blocking caspase cleavage at the critical and pathogenic aspartate 586 (D586) significantly increases posttranslational myristoylation of huntingtin. In turn, myristoylation of huntingtin promotes the co-interaction between C-terminal and N-terminal huntingtin fragments, which is also protective. Discussion: This suggests that the protective effect of inhibiting caspase-cleavage at D586 may be mediated through post-translational myristoylation of huntingtin at G553.
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11
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Kim H, Gomez-Pastor R. HSF1 and Its Role in Huntington's Disease Pathology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1410:35-95. [PMID: 36396925 DOI: 10.1007/5584_2022_742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE OF REVIEW Heat shock factor 1 (HSF1) is the master transcriptional regulator of the heat shock response (HSR) in mammalian cells and is a critical element in maintaining protein homeostasis. HSF1 functions at the center of many physiological processes like embryogenesis, metabolism, immune response, aging, cancer, and neurodegeneration. However, the mechanisms that allow HSF1 to control these different biological and pathophysiological processes are not fully understood. This review focuses on Huntington's disease (HD), a neurodegenerative disease characterized by severe protein aggregation of the huntingtin (HTT) protein. The aggregation of HTT, in turn, leads to a halt in the function of HSF1. Understanding the pathways that regulate HSF1 in different contexts like HD may hold the key to understanding the pathomechanisms underlying other proteinopathies. We provide the most current information on HSF1 structure, function, and regulation, emphasizing HD, and discussing its potential as a biological target for therapy. DATA SOURCES We performed PubMed search to find established and recent reports in HSF1, heat shock proteins (Hsp), HD, Hsp inhibitors, HSF1 activators, and HSF1 in aging, inflammation, cancer, brain development, mitochondria, synaptic plasticity, polyglutamine (polyQ) diseases, and HD. STUDY SELECTIONS Research and review articles that described the mechanisms of action of HSF1 were selected based on terms used in PubMed search. RESULTS HSF1 plays a crucial role in the progression of HD and other protein-misfolding related neurodegenerative diseases. Different animal models of HD, as well as postmortem brains of patients with HD, reveal a connection between the levels of HSF1 and HSF1 dysfunction to mutant HTT (mHTT)-induced toxicity and protein aggregation, dysregulation of the ubiquitin-proteasome system (UPS), oxidative stress, mitochondrial dysfunction, and disruption of the structural and functional integrity of synaptic connections, which eventually leads to neuronal loss. These features are shared with other neurodegenerative diseases (NDs). Currently, several inhibitors against negative regulators of HSF1, as well as HSF1 activators, are developed and hold promise to prevent neurodegeneration in HD and other NDs. CONCLUSION Understanding the role of HSF1 during protein aggregation and neurodegeneration in HD may help to develop therapeutic strategies that could be effective across different NDs.
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Affiliation(s)
- Hyuck Kim
- Department of Neuroscience, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Rocio Gomez-Pastor
- Department of Neuroscience, School of Medicine, University of Minnesota, Minneapolis, MN, USA.
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Sap KA, Geijtenbeek KW, Schipper-Krom S, Guler AT, Reits EA. Ubiquitin-modifying enzymes in Huntington's disease. Front Mol Biosci 2023; 10:1107323. [PMID: 36926679 PMCID: PMC10013475 DOI: 10.3389/fmolb.2023.1107323] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/16/2023] [Indexed: 02/10/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG repeat expansion in the N-terminus of the HTT gene. The CAG repeat expansion translates into a polyglutamine expansion in the mutant HTT (mHTT) protein, resulting in intracellular aggregation and neurotoxicity. Lowering the mHTT protein by reducing synthesis or improving degradation would delay or prevent the onset of HD, and the ubiquitin-proteasome system (UPS) could be an important pathway to clear the mHTT proteins prior to aggregation. The UPS is not impaired in HD, and proteasomes can degrade mHTT entirely when HTT is targeted for degradation. However, the mHTT protein is differently ubiquitinated when compared to wild-type HTT (wtHTT), suggesting that the polyQ expansion affects interaction with (de) ubiquitinating enzymes and subsequent targeting for degradation. The soluble mHTT protein is associated with several ubiquitin-modifying enzymes, and various ubiquitin-modifying enzymes have been identified that are linked to Huntington's disease, either by improving mHTT turnover or affecting overall homeostasis. Here we describe their potential mechanism of action toward improved mHTT targeting towards the proteostasis machinery.
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Affiliation(s)
- Karen A Sap
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Karlijne W Geijtenbeek
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Sabine Schipper-Krom
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Arzu Tugce Guler
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Eric A Reits
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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13
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Mandel N, Agarwal N. Role of SUMOylation in Neurodegenerative Diseases. Cells 2022; 11:3395. [PMID: 36359791 PMCID: PMC9654019 DOI: 10.3390/cells11213395] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/23/2022] [Accepted: 10/24/2022] [Indexed: 09/26/2023] Open
Abstract
Neurodegenerative diseases (NDDs) are irreversible, progressive diseases with no effective treatment. The hallmark of NDDs is the aggregation of misfolded, modified proteins, which impair neuronal vulnerability and cause brain damage. The loss of synaptic connection and the progressive loss of neurons result in cognitive defects. Several dysregulated proteins and overlapping molecular mechanisms contribute to the pathophysiology of NDDs. Post-translational modifications (PTMs) are essential regulators of protein function, trafficking, and maintaining neuronal hemostasis. The conjugation of a small ubiquitin-like modifier (SUMO) is a reversible, dynamic PTM required for synaptic and cognitive function. The onset and progression of neurodegenerative diseases are associated with aberrant SUMOylation. In this review, we have summarized the role of SUMOylation in regulating critical proteins involved in the onset and progression of several NDDs.
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Affiliation(s)
| | - Nitin Agarwal
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
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14
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Podvin S, Rosenthal SB, Poon W, Wei E, Fisch KM, Hook V. Mutant Huntingtin Protein Interaction Map Implicates Dysregulation of Multiple Cellular Pathways in Neurodegeneration of Huntington's Disease. J Huntingtons Dis 2022; 11:243-267. [PMID: 35871359 PMCID: PMC9484122 DOI: 10.3233/jhd-220538] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Huntington's disease (HD) is a genetic neurodegenerative disease caused by trinucleotide repeat (CAG) expansions in the human HTT gene encoding the huntingtin protein (Htt) with an expanded polyglutamine tract. OBJECTIVE HD models from yeast to transgenic mice have investigated proteins interacting with mutant Htt that may initiate molecular pathways of cell death. There is a paucity of datasets of published Htt protein interactions that include the criteria of 1) defining fragments or full-length Htt forms, 2) indicating the number of poly-glutamines of the mutant and wild-type Htt forms, and 3) evaluating native Htt interaction complexes. This research evaluated such interactor data to gain understanding of Htt dysregulation of cellular pathways. METHODS Htt interacting proteins were compiled from the literature that meet our criteria and were subjected to network analysis via clustering, gene ontology, and KEGG pathways using rigorous statistical methods. RESULTS The compiled data of Htt interactors found that both mutant and wild-type Htt interact with more than 2,971 proteins. Application of a community detection algorithm to all known Htt interactors identified significant signal transduction, membrane trafficking, chromatin, and mitochondrial clusters, among others. Binomial analyses of a subset of reported protein interactor information determined that chromatin organization, signal transduction and endocytosis were diminished, while mitochondria, translation and membrane trafficking had enriched overall edge effects. CONCLUSION The data support the hypothesis that mutant Htt disrupts multiple cellular processes causing toxicity. This dataset is an open resource to aid researchers in formulating hypotheses of HD mechanisms of pathogenesis.
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Affiliation(s)
- Sonia Podvin
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Sara Brin Rosenthal
- Center for Computational Biology & Bioinformatics, University of California, San Diego, La Jolla, CA, USA
| | - William Poon
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Enlin Wei
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Kathleen M Fisch
- Center for Computational Biology & Bioinformatics, University of California, San Diego, La Jolla, CA, USA.,Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA.,Department of Neuroscience and Dept of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, USA
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15
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Adegbuyiro A, Stonebraker AR, Sedighi F, Fan CK, Hodges B, Li P, Valentine SJ, Legleiter J. Oxidation Promotes Distinct Huntingtin Aggregates in the Presence and Absence of Membranes. Biochemistry 2022; 61:1517-1530. [PMID: 35759798 DOI: 10.1021/acs.biochem.2c00212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Expansion of a polyglutamine (polyQ) domain within the first exon of the huntingtin (htt) protein is the underlying cause of Huntington's disease, a genetic neurodegenerative disorder. PolyQ expansion triggers htt aggregation into oligomers, fibrils, and inclusions. The 17 N-terminal amino acids (Nt17) of htt-exon1, which directly precede the polyQ domain enhances polyQ fibrillization and functions as a lipid-binding domain. A variety of post-translational modifications occur within Nt17, including oxidation of two methionine residues. Here, the impact of oxidation within Nt17 on htt aggregation both in the presence and absence of lipid membranes was investigated. Treatment with hydrogen peroxide (H2O2) reduced fibril formation in a dose-dependent manner, resulting in shorter fibrils and an increased oligomer population. With excessive H2O2 treatments, fibrils developed a unique morphological feature around their periphery. In the presence of total brain lipid vesicles, H2O2 impacted fibrillization in a similar manner. That is, oligomerization was promoted at the expense of fibril elongation. The interaction of unoxidized and oxidized htt with supported lipid bilayers was directly observed using in situ atomic force microscopy. Without oxidation, granular htt aggregates developed on the bilayer surface. However, in the presence of H2O2, distinct plateau-like regions initially developed on the bilayer surface that gave way to rougher patches containing granular aggregates. Collectively, these observations suggest that oxidation of methionine residues within Nt17 plays a crucial role in both the aggregation of htt and its ability to interact with lipid surfaces.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Alyssa R Stonebraker
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Caleb K Fan
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Breanna Hodges
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Peng Li
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Stephen J Valentine
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States.,Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, West Virginia 26505, United States.,Department of Neuroscience, West Virginia University, 1 Medical Center Dr., P.O. Box 9303, Morgantown, West Virginia 26505, United States
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16
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Huntingtin Ubiquitination Mechanisms and Novel Possible Therapies to Decrease the Toxic Effects of Mutated Huntingtin. J Pers Med 2021; 11:jpm11121309. [PMID: 34945781 PMCID: PMC8709430 DOI: 10.3390/jpm11121309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/19/2021] [Accepted: 11/21/2021] [Indexed: 12/24/2022] Open
Abstract
Huntington Disease (HD) is a dominant, lethal neurodegenerative disorder caused by the abnormal expansion (>35 copies) of a CAG triplet located in exon 1 of the HTT gene encoding the huntingtin protein (Htt). Mutated Htt (mHtt) easily aggregates, thereby inducing ER stress that in turn leads to neuronal injury and apoptosis. Therefore, both the inhibition of mHtt aggregate formation and the acceleration of mHtt degradation represent attractive strategies to delay HD progression, and even for HD treatment. Here, we describe the mechanism underlying mHtt degradation by the ubiquitin–proteasome system (UPS), which has been shown to play a more important role than the autophagy–lysosomal pathway. In particular, we focus on E3 ligase proteins involved in the UPS and detail their structure–function relationships. In this framework, we discuss the possible exploitation of PROteolysis TArgeting Chimeras (PROTACs) for HD therapy. PROTACs are heterobifunctional small molecules that comprise two different ligands joined by an appropriate linker; one of the ligands is specific for a selected E3 ubiquitin ligase, the other ligand is able to recruit a target protein of interest, in this case mHtt. As a consequence of PROTAC binding, mHtt and the E3 ubiquitin ligase can be brought to a relative position that allows mHtt to be ubiquitinated and, ultimately, allows a reduction in the amount of mHtt in the cell.
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17
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Sawant N, Morton H, Kshirsagar S, Reddy AP, Reddy PH. Mitochondrial Abnormalities and Synaptic Damage in Huntington's Disease: a Focus on Defective Mitophagy and Mitochondria-Targeted Therapeutics. Mol Neurobiol 2021; 58:6350-6377. [PMID: 34519969 DOI: 10.1007/s12035-021-02556-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/05/2021] [Indexed: 12/12/2022]
Abstract
Huntington's disease (HD) is a fatal and pure genetic disease with a progressive loss of medium spiny neurons (MSN). HD is caused by expanded polyglutamine repeats in the exon 1 of HD gene. Clinically, HD is characterized by chorea, seizures, involuntary movements, dystonia, cognitive decline, intellectual impairment, and emotional disturbances. Several years of intense research revealed that multiple cellular changes, including defective axonal transport, protein-protein interactions, defective bioenergetics, calcium dyshomeostasis, NMDAR activation, synaptic damage, mitochondrial abnormalities, and selective loss of medium spiny neurons are implicated in HD. Recent research on mutant huntingtin (mHtt) and mitochondria has found that mHtt interacts with the mitochondrial division protein, dynamin-related protein 1 (DRP1), enhances GTPase DRP1 enzymatic activity, and causes excessive mitochondrial fragmentation and abnormal distribution, leading to defective axonal transport of mitochondria and selective synaptic degeneration. Recent research also revealed that failure to remove dead and/or dying mitochondria is an early event in the disease progression. Currently, efforts are being made to reduce abnormal protein interactions and enhance synaptic mitophagy as therapeutic strategies for HD. The purpose of this article is to discuss recent research in HD progression. This article also discusses recent developments of cell and mouse models, cellular changes, mitochondrial abnormalities, DNA damage, bioenergetics, oxidative stress, mitophagy, and therapeutics strategies in HD.
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Affiliation(s)
- Neha Sawant
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Hallie Morton
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Sudhir Kshirsagar
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Arubala P Reddy
- Nutritional Sciences Department, College of Human Sciences, Texas Tech University, 1301 Akron Ave, Lubbock, TX, USA
| | - P Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Neurology, Department of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
- Department of Internal Medicine, Cell Biology & Biochemistry, Public Health and School of Health Professions, Texas Tech University Health Sciences Center, Neuroscience & Pharmacology3601 4th Street, NeurologyLubbock, TX, 79430, USA.
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18
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George DE, Tepe JJ. Advances in Proteasome Enhancement by Small Molecules. Biomolecules 2021; 11:1789. [PMID: 34944433 PMCID: PMC8699248 DOI: 10.3390/biom11121789] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 01/11/2023] Open
Abstract
The proteasome system is a large and complex molecular machinery responsible for the degradation of misfolded, damaged, and redundant cellular proteins. When proteasome function is impaired, unwanted proteins accumulate, which can lead to several diseases including age-related and neurodegenerative diseases. Enhancing proteasome-mediated substrate degradation with small molecules may therefore be a valuable strategy for the treatment of various neurodegenerative diseases such as Parkinson's, Alzheimer's, and Huntington's diseases. In this review, we discuss the structure of proteasome and how proteasome's proteolytic activity is associated with aging and various neurodegenerative diseases. We also summarize various classes of compounds that are capable of enhancing, directly or indirectly, proteasome-mediated protein degradation.
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Affiliation(s)
| | - Jetze J. Tepe
- Department of Chemistry and Pharmacology & Toxicology, Michigan State University, East Lansing, MI 48824, USA;
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19
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Hommen F, Bilican S, Vilchez D. Protein clearance strategies for disease intervention. J Neural Transm (Vienna) 2021; 129:141-172. [PMID: 34689261 PMCID: PMC8541819 DOI: 10.1007/s00702-021-02431-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/10/2021] [Indexed: 02/06/2023]
Abstract
Protein homeostasis, or proteostasis, is essential for cell function and viability. Unwanted, damaged, misfolded and aggregated proteins are degraded by the ubiquitin–proteasome system (UPS) and the autophagy-lysosome pathway. Growing evidence indicates that alterations in these major proteolytic mechanisms lead to a demise in proteostasis, contributing to the onset and development of distinct diseases. Indeed, dysregulation of the UPS or autophagy is linked to several neurodegenerative, infectious and inflammatory disorders as well as cancer. Thus, modulation of protein clearance pathways is a promising approach for therapeutics. In this review, we discuss recent findings and open questions on how targeting proteolytic mechanisms could be applied for disease intervention.
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Affiliation(s)
- Franziska Hommen
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, 50931, Cologne, Germany
| | - Saygın Bilican
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, 50931, Cologne, Germany
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph Stelzmann Strasse 26, 50931, Cologne, Germany. .,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany. .,Faculty of Medicine, University Hospital Cologne, Cologne, Germany.
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20
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Middleton AJ, Teyra J, Zhu J, Sidhu SS, Day CL. Identification of Ubiquitin Variants That Inhibit the E2 Ubiquitin Conjugating Enzyme, Ube2k. ACS Chem Biol 2021; 16:1745-1756. [PMID: 34397214 DOI: 10.1021/acschembio.1c00445] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Transfer of ubiquitin to substrate proteins regulates most processes in eukaryotic cells. E2 enzymes are a central component of the ubiquitin machinery, and generally determine the type of ubiquitin signal generated and thus the ultimate fate of substrate proteins. The E2, Ube2k, specifically builds degradative ubiquitin chains on diverse substrates. Here we have identified protein-based reagents, called ubiquitin variants (UbVs), that bind tightly and specifically to Ube2k. Crystal structures reveal that the UbVs bind to the E2 enzyme at a hydrophobic cleft that is distinct from the active site and previously identified ubiquitin binding sites. We demonstrate that the UbVs are potent inhibitors of Ube2k and block both ubiquitin charging of the E2 enzyme and E3-catalyzed ubiquitin transfer. The binding site of the UbVs suggests they directly clash with the ubiquitin activating enzyme, while potentially disrupting interactions with E3 ligases via allosteric effects. Our data reveal the first protein-based inhibitors of Ube2k and unveil a hydrophobic groove that could be an effective target for inhibiting Ube2k and other E2 enzymes.
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Affiliation(s)
- Adam J. Middleton
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Joan Teyra
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada
| | - Jingyi Zhu
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Sachdev S. Sidhu
- The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada
| | - Catherine L. Day
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
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21
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Lemarié FL, Caron NS, Sanders SS, Schmidt ME, Nguyen YTN, Ko S, Xu X, Pouladi MA, Martin DDO, Hayden MR. Rescue of aberrant huntingtin palmitoylation ameliorates mutant huntingtin-induced toxicity. Neurobiol Dis 2021; 158:105479. [PMID: 34390831 DOI: 10.1016/j.nbd.2021.105479] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 07/29/2021] [Accepted: 08/09/2021] [Indexed: 01/14/2023] Open
Abstract
Huntington disease (HD) is a neurodegenerative disorder caused by a CAG expansion in the HTT gene that codes for an elongated polyglutamine tract in the huntingtin (HTT) protein. HTT is subject to multiple post-translational modifications (PTMs) that regulate its cellular function. Mutating specific PTM sites within mutant HTT (mHTT) in HD mouse models can modulate disease phenotypes, highlighting the key role of HTT PTMs in the pathogenesis of HD. These findings have led to increased interest in developing small molecules to modulate HTT PTMs in order to decrease mHTT toxicity. However, the therapeutic efficacy of pharmacological modulation of HTT PTMs in preclinical HD models remains largely unknown. HTT is palmitoylated at cysteine 214 by the huntingtin-interacting protein 14 (HIP14 or ZDHHC17) and 14-like (HIP14L or ZDHHC13) acyltransferases. Here, we assessed if HTT palmitoylation should be regarded as a therapeutic target to treat HD by (1) investigating palmitoylation dysregulation in rodent and human HD model systems, (2) measuring the impact of mHTT-lowering therapy on brain palmitoylation, and (3) evaluating if HTT palmitoylation can be pharmacologically modulated. We show that palmitoylation of mHTT and some HIP14/HIP14L-substrates is decreased early in multiple HD mouse models, and that mHTT palmitoylation decreases further with aging. Lowering mHTT in the brain of YAC128 mice is not sufficient to rescue aberrant palmitoylation. However, we demonstrate that mHTT palmitoylation can be normalized in COS-7 cells, in YAC128 cortico-striatal primary neurons and HD patient-derived lymphoblasts using an acyl-protein thioesterase (APT) inhibitor. Moreover, we show that modulating palmitoylation reduces mHTT aggregation and mHTT-induced cytotoxicity in COS-7 cells and YAC128 neurons.
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Affiliation(s)
- Fanny L Lemarié
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Nicholas S Caron
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Shaun S Sanders
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada; Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Mandi E Schmidt
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Yen T N Nguyen
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Seunghyun Ko
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Xiaohong Xu
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China; Translational Laboratory in Genetic Medicine, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Mahmoud A Pouladi
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada; Translational Laboratory in Genetic Medicine, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Dale D O Martin
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada; Department of Biology, University of Waterloo, Waterloo, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada.
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Nargeh H, Aliabadi F, Ajami M, Pazoki-Toroudi H. Role of Polyphenols on Gut Microbiota and the Ubiquitin-Proteasome System in Neurodegenerative Diseases. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6119-6144. [PMID: 34038102 DOI: 10.1021/acs.jafc.1c00923] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Today, neurodegenerative diseases have become a remarkable public health challenge due to their direct relation with aging. Accordingly, understanding the molecular and cellular mechanisms occurring in the pathogenesis of them is essential. Both protein aggregations as a result of the ubiquitin-proteasome system (UPS) inefficiency and gut microbiota alternation are the main pathogenic hallmarks. Polyphenols upregulating this system may decrease the developing rate of neurodegenerative diseases. Most of the dietary intake of polyphenols is converted into other microbial metabolites, which have completely different biological properties from the original polyphenols and should be thoroughly investigated. Herein, several prevalent neurodegenerative diseases are pinpointed to explain the role of gut microbiota alternations and the role of molecular changes, especially UPS down-regulation in their pathogenesis. Some of the most important polyphenols found in our diet are explained along with their microbial metabolites in the body.
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Affiliation(s)
- Hanieh Nargeh
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran 1417466191, Iran
| | - Fatemeh Aliabadi
- Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran 14535, Iran
| | - Marjan Ajami
- Faculty of Nutrition Sciences & Food Technology, Shahid Beheshti University of Medical Sciences, 7th Floor, Bldg No. 2 SBUMS, Arabi Avenue, Daneshjoo Boulevard, Velenjak, Tehran 19839-63113, Iran
| | - Hamidreza Pazoki-Toroudi
- Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran 14535, Iran
- Department of Physiology and Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran 14535, Iran
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23
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Liu X, Yin L, Li T, Lin L, Zhang J, Li Y. Reduction of WDR81 impairs autophagic clearance of aggregated proteins and cell viability in neurodegenerative phenotypes. PLoS Genet 2021; 17:e1009415. [PMID: 33730050 PMCID: PMC7968681 DOI: 10.1371/journal.pgen.1009415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 02/11/2021] [Indexed: 12/17/2022] Open
Abstract
Neurodegenerative diseases are characterized by neuron loss and accumulation of undegraded protein aggregates. These phenotypes are partially due to defective protein degradation in neuronal cells. Autophagic clearance of aggregated proteins is critical to protein quality control, but the underlying mechanisms are still poorly understood. Here we report the essential role of WDR81 in autophagic clearance of protein aggregates in models of Huntington’s disease (HD), Parkinson’s disease (PD) and Alzheimer’s disease (AD). In hippocampus and cortex of patients with HD, PD and AD, protein level of endogenous WDR81 is decreased but autophagic receptor p62 accumulates significantly. WDR81 facilitates the recruitment of autophagic proteins onto Htt polyQ aggregates and promotes autophagic clearance of Htt polyQ subsequently. The BEACH and MFS domains of WDR81 are sufficient for its recruitment onto Htt polyQ aggregates, and its WD40 repeats are essential for WDR81 interaction with covalent bound ATG5-ATG12. Reduction of WDR81 impairs the viability of mouse primary neurons, while overexpression of WDR81 restores the viability of fibroblasts from HD patients. Notably, in Caenorhabditis elegans, deletion of the WDR81 homolog (SORF-2) causes accumulation of p62 bodies and exacerbates neuron loss induced by overexpressed α-synuclein. As expected, overexpression of SORF-2 or human WDR81 restores neuron viability in worms. These results demonstrate that WDR81 has crucial evolutionarily conserved roles in autophagic clearance of protein aggregates and maintenance of cell viability under pathological conditions, and its reduction provides mechanistic insights into the pathogenesis of HD, PD, AD and brain disorders related to WDR81 mutations. In recent years, a group of clinical studies reported that mutations of WDR81 are related to pathogenesis of human brain disorders. However, the underlying mechanisms of pathogenesis are still unknown. In this study, WDR81 promotes the autophagic clearance of protein aggregates via facilitating the recruitment of autophagic proteins onto protein aggregates. The BEACH and MFS domains of WDR81 are sufficient for its recruitment onto Htt polyQ aggregates, and its WD40 repeats are essential for WDR81 interaction with covalent bound ATG5-ATG12. In hippocampus and cortex of patients with HD, PD and AD, protein level of WDR81 is decreased significantly. Reduction of WDR81 impairs the viability of mouse primary neurons, while overexpression of WDR81 restores the viability of fibroblasts from HD patients.
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Affiliation(s)
- Xuezhao Liu
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China
- Division of Experimental Hematology and Cancer Biology, Department of Pediatrics, Brain Tumor Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, United States of America
| | - Limin Yin
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Bioactive Small Molecules, Fudan University, Shanghai, China
| | - Tianyou Li
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Bioactive Small Molecules, Fudan University, Shanghai, China
| | - Lingxi Lin
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China
| | - Jie Zhang
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Bioactive Small Molecules, Fudan University, Shanghai, China
| | - Yang Li
- Department of Pharmacology, School of Basic Medical Science, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Bioactive Small Molecules, Fudan University, Shanghai, China
- * E-mail:
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24
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Pluska L, Jarosch E, Zauber H, Kniss A, Waltho A, Bagola K, von Delbrück M, Löhr F, Schulman BA, Selbach M, Dötsch V, Sommer T. The UBA domain of conjugating enzyme Ubc1/Ube2K facilitates assembly of K48/K63-branched ubiquitin chains. EMBO J 2021; 40:e106094. [PMID: 33576509 PMCID: PMC7957398 DOI: 10.15252/embj.2020106094] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 12/22/2020] [Accepted: 01/05/2021] [Indexed: 12/23/2022] Open
Abstract
The assembly of a specific polymeric ubiquitin chain on a target protein is a key event in the regulation of numerous cellular processes. Yet, the mechanisms that govern the selective synthesis of particular polyubiquitin signals remain enigmatic. The homologous ubiquitin-conjugating (E2) enzymes Ubc1 (budding yeast) and Ube2K (mammals) exclusively generate polyubiquitin linked through lysine 48 (K48). Uniquely among E2 enzymes, Ubc1 and Ube2K harbor a ubiquitin-binding UBA domain with unknown function. We found that this UBA domain preferentially interacts with ubiquitin chains linked through lysine 63 (K63). Based on structural modeling, in vitro ubiquitination experiments, and NMR studies, we propose that the UBA domain aligns Ubc1 with K63-linked polyubiquitin and facilitates the selective assembly of K48/K63-branched ubiquitin conjugates. Genetic and proteomics experiments link the activity of the UBA domain, and hence the formation of this unusual ubiquitin chain topology, to the maintenance of cellular proteostasis.
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Affiliation(s)
- Lukas Pluska
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz AssociationBerlin‐BuchGermany
| | - Ernst Jarosch
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz AssociationBerlin‐BuchGermany
| | - Henrik Zauber
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz AssociationBerlin‐BuchGermany
| | - Andreas Kniss
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic ResonanceGoethe UniversityFrankfurt am MainGermany
| | - Anita Waltho
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz AssociationBerlin‐BuchGermany
| | - Katrin Bagola
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz AssociationBerlin‐BuchGermany
| | | | - Frank Löhr
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic ResonanceGoethe UniversityFrankfurt am MainGermany
| | - Brenda A Schulman
- Department of Molecular Machines and SignalingMax Planck Institute of BiochemistryMartinsriedGermany
| | - Matthias Selbach
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz AssociationBerlin‐BuchGermany
- Charité – Universitätsmedizin BerlinBerlinGermany
| | - Volker Dötsch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic ResonanceGoethe UniversityFrankfurt am MainGermany
| | - Thomas Sommer
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz AssociationBerlin‐BuchGermany
- Institute for BiologyHumboldt‐Universität zu BerlinBerlinGermany
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25
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Kurvits L, Lättekivi F, Reimann E, Kadastik-Eerme L, Kasterpalu KM, Kõks S, Taba P, Planken A. Transcriptomic profiles in Parkinson's disease. Exp Biol Med (Maywood) 2021; 246:584-595. [PMID: 33148011 PMCID: PMC7934142 DOI: 10.1177/1535370220967325] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/17/2020] [Indexed: 12/31/2022] Open
Abstract
Transcriptomics in Parkinson's disease offers insights into the pathogenesis of Parkinson's disease but obtaining brain tissue has limitations. In order to bypass this issue, we profile and compare differentially expressed genes and enriched pathways (KEGG) in two peripheral tissues (blood and skin) of 12 Parkinson's disease patients and 12 healthy controls using RNA-sequencing technique and validation with RT-qPCR. Furthermore, we compare our results to previous Parkinson's disease post mortem brain tissue and blood results using the robust rank aggregation method. The results show no overlapping differentially expressed genes or enriched pathways in blood vs. skin in our sample sets (25 vs. 1068 differentially expressed genes with an FDR ≤ 0.05; 1 vs. 9 pathways in blood and skin, respectively). A meta-analysis from previous transcriptomic sample sets using either microarrays or RNA-Seq yields a robust rank aggregation list of cortical gene expression changes with 43 differentially expressed genes; a list of substantia nigra changes with 2 differentially expressed genes and a list of blood changes with 1 differentially expressed gene being statistically significant at FDR ≤ 0.05. In cortex 1, KEGG pathway was enriched, four in substantia nigra and two in blood. None of the differentially expressed genes or pathways overlap between these tissues. When comparing our previously published skin transcription analysis, two differentially expressed genes between the cortex robust rank aggregation and skin overlap. In this study, for the first time a meta-analysis is applied on transcriptomic sample sets in Parkinson's disease. Simultaneously, it explores the notion that Parkinson's disease is not just a neuronal tissue disease by exploring peripheral tissues. The comparison of different Parkinson's disease tissues yields surprisingly few significant differentially expressed genes and pathways, suggesting that divergent gene expression profiles in distinct cell lineages, metabolic and possibly iatrogenic effects create too much transcriptomic noise for detecting significant signal. On the other hand, there are signs that point towards Parkinson's disease-specific changes in non-neuronal peripheral tissues in Parkinson's disease, indicating that Parkinson's disease might be a multisystem disorder.
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Affiliation(s)
- Lille Kurvits
- Department of Neurology and Neurosurgery, University of Tartu, Tartu 50406, Estonia
- Department of Neurology, Charité – Universitätsmedizin Berlin, Berlin 10117, Germany
| | - Freddy Lättekivi
- Institute of Pathophysiology, University of Tartu, Tartu 50411, Estonia
| | - Ene Reimann
- Estonian Genome Center Science Center, Institute of Genomics, University of Tartu, Tartu 51010, Estonia
| | - Liis Kadastik-Eerme
- Department of Neurology and Neurosurgery, University of Tartu, Tartu 50406, Estonia
- Neurology Clinic, Tartu University Hospital, Tartu 50406, Estonia
| | | | - Sulev Kõks
- Centre for Comparative Genomics, Murdoch University, Perth, WA 6150, Australia
- Perron Institute for Neurological and Translational Science, University of Western Australia, QE II Medical Centre, Nedlands, WA 6009, Australia
| | - Pille Taba
- Department of Neurology and Neurosurgery, University of Tartu, Tartu 50406, Estonia
- Neurology Clinic, Tartu University Hospital, Tartu 50406, Estonia
| | - Anu Planken
- Department of Neurology and Neurosurgery, University of Tartu, Tartu 50406, Estonia
- Neurology Clinic, Tartu University Hospital, Tartu 50406, Estonia
- Oncology and Haematology Clinic, North-Estonian Medical Centre, Tallinn 13419, Estonia
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26
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Devi S, Kim JJ, Singh AP, Kumar S, Dubey AK, Singh SK, Singh RS, Kumar V. Proteotoxicity: A Fatal Consequence of Environmental Pollutants-Induced Impairments in Protein Clearance Machinery. J Pers Med 2021; 11:69. [PMID: 33503824 PMCID: PMC7912547 DOI: 10.3390/jpm11020069] [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: 12/31/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 02/08/2023] Open
Abstract
A tightly regulated protein quality control (PQC) system maintains a healthy balance between correctly folded and misfolded protein species. This PQC system work with the help of a complex network comprised of molecular chaperones and proteostasis. Any intruder, especially environmental pollutants, disrupt the PQC network and lead to PQCs disruption, thus generating damaged and infectious protein. These misfolded/unfolded proteins are linked to several diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and cataracts. Numerous studies on proteins misfolding and disruption of PQCs by environmental pollutants highlight the necessity of detailed knowledge. This review represents the PQCs network and environmental pollutants' impact on the PQC network, especially through the protein clearance system.
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Affiliation(s)
- Shweta Devi
- Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, Lucknow 226001, India;
| | - Jong-Joo Kim
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea;
| | - Anand Prakash Singh
- Division of Cardiovascular Disease, The University of Alabama at Birmingham (UAB), 1720 2nd Ave South, Birmingham, AL 35294-1913, USA;
| | - Surendra Kumar
- Cytogenetics Lab, Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India;
| | | | | | - Ravi Shankar Singh
- Department of Biochemistry, Microbiology & Immunology, University of Saskatchewan, Room 4D40, Health Sciences Building, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada
| | - Vijay Kumar
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea;
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27
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Association with proteasome determines pathogenic threshold of polyglutamine expansion diseases. Biochem Biophys Res Commun 2020; 536:95-99. [PMID: 33370719 DOI: 10.1016/j.bbrc.2020.12.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 12/18/2020] [Indexed: 11/21/2022]
Abstract
Expansion of glutamine residue track (polyQ) within soluble protein is responsible for eight autosomal-dominant genetic neurodegenerative disorders. These disorders affect cerebellum, striatum, basal ganglia and other brain regions. Each disease develops when polyQ expansion exceeds a pathogenic threshold (Qth). A pathogenic threshold is unique for each disease but the reasons for variability in Qth within this family of proteins are poorly understood. In the previous publication we proposed that polarity of the regions flanking polyQ track in each protein plays a key role in defining Qth value [1]. To explain the correlation between the polarity of the flanking sequences and Qth we performed quantitative analysis of interactions between polyQ-expanded proteins and proteasome. Based on structural and theoretical modeling, we predict that Qth value is determined by the energy of polar interaction of the flanking regions with the polyQ and proteasome. More polar flanking regions facilitate unfolding of α-helical polyQ conformation adopted inside the proteasome and as a result, increase Qth. Predictions of our model are consistent with Qth values observed in clinic for each of the eight polyQ-expansion disorders. Our results suggest that the agents that can destabilize polyQ α-helical structure may have a beneficial therapeutic effect for treatment of polyQ-expansion disorders.
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28
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The UBC27-AIRP3 ubiquitination complex modulates ABA signaling by promoting the degradation of ABI1 in Arabidopsis. Proc Natl Acad Sci U S A 2020; 117:27694-27702. [PMID: 33077597 DOI: 10.1073/pnas.2007366117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Abscisic acid (ABA) is the key phytohormone in plant drought tolerance and stress adaptation. The clade A protein phosphatase 2Cs (PP2Cs) like ABI1 (ABA-INSENSITIVE 1) work as coreceptors of ABA and regulate multiple ABA responses. Ubiquitination of ABI1 has been proven to play important regulatory roles in ABA signaling. However, the specific ubiquitin conjugating enzyme (E2) involved is unknown. Here, we report that UBC27 is an active E2 that positively regulates ABA signaling and drought tolerance. UBC27 forms the E2-E3 pair with the drought regulator RING E3 ligase AIRP3. Both UBC27 and AIRP3 interact with ABI1 and affect the ubiquitination and degradation of ABI1. ABA activates the expression of UBC27, inhibits the proteasome degradation of UBC27, and enhances the interaction between UBC27 and ABI1 to increase its activity. These findings uncover a regulatory mechanism in ABA signaling and drought response and provide a further understanding of the plant ubiquitination system and ABA signaling pathway.
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29
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Folci A, Mirabella F, Fossati M. Ubiquitin and Ubiquitin-Like Proteins in the Critical Equilibrium between Synapse Physiology and Intellectual Disability. eNeuro 2020; 7:ENEURO.0137-20.2020. [PMID: 32719102 PMCID: PMC7544190 DOI: 10.1523/eneuro.0137-20.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/08/2020] [Accepted: 06/17/2020] [Indexed: 01/04/2023] Open
Abstract
Posttranslational modifications (PTMs) represent a dynamic regulatory system that precisely modulates the functional organization of synapses. PTMs consist in target modifications by small chemical moieties or conjugation of lipids, sugars or polypeptides. Among them, ubiquitin and a large family of ubiquitin-like proteins (UBLs) share several features such as the structure of the small protein modifiers, the enzymatic cascades mediating the conjugation process, and the targeted aminoacidic residue. In the brain, ubiquitination and two UBLs, namely sumoylation and the recently discovered neddylation orchestrate fundamental processes including synapse formation, maturation and plasticity, and their alteration is thought to contribute to the development of neurological disorders. Remarkably, emerging evidence suggests that these pathways tightly interplay to modulate the function of several proteins that possess pivotal roles for brain homeostasis as well as failure of this crosstalk seems to be implicated in the development of brain pathologies. In this review, we outline the role of ubiquitination, sumoylation, neddylation, and their functional interplay in synapse physiology and discuss their implication in the molecular pathogenesis of intellectual disability (ID), a neurodevelopmental disorder that is frequently comorbid with a wide spectrum of brain pathologies. Finally, we propose a few outlooks that might contribute to better understand the complexity of these regulatory systems in regard to neuronal circuit pathophysiology.
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Affiliation(s)
- Alessandra Folci
- Humanitas Clinical and Research Center-IRCCS, via Manzoni 56, 20089, Rozzano (MI), Italy
| | - Filippo Mirabella
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20090 Pieve 9 Emanuele - Milan, Italy
| | - Matteo Fossati
- Humanitas Clinical and Research Center-IRCCS, via Manzoni 56, 20089, Rozzano (MI), Italy
- CNR-Institute of Neuroscience, via Manzoni 56, 20089, Rozzano (MI), Italy
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30
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Lopata A, Kniss A, Löhr F, Rogov VV, Dötsch V. Ubiquitination in the ERAD Process. Int J Mol Sci 2020; 21:ijms21155369. [PMID: 32731622 PMCID: PMC7432864 DOI: 10.3390/ijms21155369] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/23/2020] [Accepted: 07/27/2020] [Indexed: 01/08/2023] Open
Abstract
In this review, we focus on the ubiquitination process within the endoplasmic reticulum associated protein degradation (ERAD) pathway. Approximately one third of all synthesized proteins in a cell are channeled into the endoplasmic reticulum (ER) lumen or are incorporated into the ER membrane. Since all newly synthesized proteins enter the ER in an unfolded manner, folding must occur within the ER lumen or co-translationally, rendering misfolding events a serious threat. To prevent the accumulation of misfolded protein in the ER, proteins that fail the quality control undergo retrotranslocation into the cytosol where they proceed with ubiquitination and degradation. The wide variety of misfolded targets requires on the one hand a promiscuity of the ubiquitination process and on the other hand a fast and highly processive mechanism. We present the various ERAD components involved in the ubiquitination process including the different E2 conjugating enzymes, E3 ligases, and E4 factors. The resulting K48-linked and K11-linked ubiquitin chains do not only represent a signal for degradation by the proteasome but are also recognized by the AAA+ ATPase Cdc48 and get in the process of retrotranslocation modified by enzymes bound to Cdc48. Lastly we discuss the conformations adopted in particular by K48-linked ubiquitin chains and their importance for degradation.
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31
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The ubiquitin-conjugating enzyme UBE2K determines neurogenic potential through histone H3 in human embryonic stem cells. Commun Biol 2020; 3:262. [PMID: 32451438 PMCID: PMC7248108 DOI: 10.1038/s42003-020-0984-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 05/01/2020] [Indexed: 01/05/2023] Open
Abstract
Histones modulate gene expression by chromatin compaction, regulating numerous processes such as differentiation. However, the mechanisms underlying histone degradation remain elusive. Human embryonic stem cells (hESCs) have a unique chromatin architecture characterized by low levels of trimethylated histone H3 at lysine 9 (H3K9me3), a heterochromatin-associated modification. Here we assess the link between the intrinsic epigenetic landscape and ubiquitin-proteasome system of hESCs. We find that hESCs exhibit high expression of the ubiquitin-conjugating enzyme UBE2K. Loss of UBE2K upregulates the trimethyltransferase SETDB1, resulting in H3K9 trimethylation and repression of neurogenic genes during differentiation. Besides H3K9 trimethylation, UBE2K binds histone H3 to induce its polyubiquitination and degradation by the proteasome. Notably, ubc-20, the worm orthologue of UBE2K, also regulates histone H3 levels and H3K9 trimethylation in Caenorhabditis elegans germ cells. Thus, our results indicate that UBE2K crosses evolutionary boundaries to promote histone H3 degradation and reduce H3K9me3 repressive marks in immortal cells. Azra Fatima et al. show that ubiquitin-conjugating enzyme UBE2K regulates neurogenic potential through its target histone H3 in human embryonic stem cells. This study suggests that UBE2K promotes histone H3 degradation, reducing the H3K9me3 repressive marks in immortal cells of both worms and humans.
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32
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Momtaz S, Memariani Z, El-Senduny FF, Sanadgol N, Golab F, Katebi M, Abdolghaffari AH, Farzaei MH, Abdollahi M. Targeting Ubiquitin-Proteasome Pathway by Natural Products: Novel Therapeutic Strategy for Treatment of Neurodegenerative Diseases. Front Physiol 2020; 11:361. [PMID: 32411012 PMCID: PMC7199656 DOI: 10.3389/fphys.2020.00361] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 03/27/2020] [Indexed: 12/11/2022] Open
Abstract
Misfolded proteins are the main common feature of neurodegenerative diseases, thereby, normal proteostasis is an important mechanism to regulate the neural survival and the central nervous system functionality. The ubiquitin-proteasome system (UPS) is a non-lysosomal proteolytic pathway involved in numerous normal functions of the nervous system, modulation of neurotransmitter release, synaptic plasticity, and recycling of membrane receptors or degradation of damaged and regulatory intracellular proteins. Aberrant accumulation of intracellular ubiquitin-positive inclusions has been implicated to a variety of neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington disease (HD), Amyotrophic Lateral Sclerosis (ALS), and Multiple Myeloma (MM). Genetic mutation in deubiquitinating enzyme could disrupt UPS and results in destructive effects on neuron survival. To date, various agents were characterized with proteasome-inhibitory potential. Proteins of the ubiquitin-proteasome system, and in particular, E3 ubiquitin ligases, may be promising molecular targets for neurodegenerative drug discovery. Phytochemicals, specifically polyphenols (PPs), were reported to act as proteasome-inhibitors or may modulate the proteasome activity. PPs modify the UPS by means of accumulation of ubiquitinated proteins, suppression of neuronal apoptosis, reduction of neurotoxicity, and improvement of synaptic plasticity and transmission. This is the first comprehensive review on the effect of PPs on UPS. Here, we review the recent findings describing various aspects of UPS dysregulation in neurodegenerative disorders. This review attempts to summarize the latest reports on the neuroprotective properties involved in the proper functioning of natural polyphenolic compounds with implication for targeting ubiquitin-proteasome pathway in the neurodegenerative diseases. We highlight the evidence suggesting that polyphenolic compounds have a dose and disorder dependent effects in improving neurological dysfunctions, and so their mechanism of action could stimulate the UPS, induce the protein degradation or inhibit UPS and reduce protein degradation. Future studies should focus on molecular mechanisms by which PPs can interfere this complex regulatory system at specific stages of the disease development and progression.
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Affiliation(s)
- Saeideh Momtaz
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran.,Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran.,Gastrointestinal Pharmacology Interest Group, Universal Scientific Education and Research Network, Tehran, Iran
| | - Zahra Memariani
- Traditional Medicine and History of Medical Sciences Research Center, Health Research Center, Babol University of Medical Sciences, Babol, Iran
| | | | - Nima Sanadgol
- Department of Biology, Faculty of Sciences, University of Zabol, Zabol, Iran.,Department of Biomolecular Sciences, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, Brazil
| | - Fereshteh Golab
- Cellular and Molecular Research Center, Iran University of Medical Science, Tehran, Iran
| | - Majid Katebi
- Department of Anatomy, Faculty of Medicine, Hormozgan University of Medical Sciences, Hormozgan, Iran
| | - Amir Hossein Abdolghaffari
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran.,Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran.,Gastrointestinal Pharmacology Interest Group, Universal Scientific Education and Research Network, Tehran, Iran.,Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Mohammad Hosein Farzaei
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohammad Abdollahi
- Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran.,Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
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33
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Sedighi F, Adegbuyiro A, Legleiter J. SUMOylation Prevents Huntingtin Fibrillization and Localization onto Lipid Membranes. ACS Chem Neurosci 2020; 11:328-343. [PMID: 31880908 DOI: 10.1021/acschemneuro.9b00509] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD), a genetic neurodegenerative disease, is caused by an expanded polyglutamine (polyQ) domain in the first exon of the huntingtin protein (htt). PolyQ expansion destabilizes protein structure, resulting in aggregation into a variety of oligomers, protofibrils, and fibrils. Beyond the polyQ domain, adjacent protein sequences influence the aggregation process. Specifically, the first 17 N-terminal amino acids (Nt17) directly preceding the polyQ domain promote the formation of α-helix-rich oligomers that represent intermediate species associated with fibrillization. Due to its propensity to form an amphipathic α-helix, Nt17 also facilitates lipid binding. Three lysine residues (K6, K9, and K15) within Nt17 can be SUMOylated, which modifies htt's accumulation and toxicity within cells in a variety of HD models. The impact of SUMOylation on htt aggregation and direct interaction with lipid membranes was investigated. SUMOylation of htt-exon1 inhibited fibril formation while promoting larger, amorphous aggregate species. These amorphous aggregates were SDS soluble but nonetheless exhibited levels of β-sheet structure similar to that of htt-exon1 fibrils. In addition, SUMOylation prevented htt binding, aggregation, and accumulation on model lipid bilayers comprised of total brain lipid extract. Collectively, these observations demonstrate that SUMOylation promotes a distinct htt aggregation pathway that may affect htt toxicity.
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Affiliation(s)
- Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
- Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
- Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
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34
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Wu J, Tian B, Yang J, Huo H, Song Z, Yu J, Gu Y. Reduction of Hip2 suppresses gastric cancer cell proliferation, migration, invasion and tumorigenesis. Transl Cancer Res 2020; 9:774-785. [PMID: 35117423 PMCID: PMC8798881 DOI: 10.21037/tcr.2019.12.12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 11/15/2019] [Indexed: 02/02/2023]
Abstract
Background Hip2, a ubiquitin-conjugating enzyme, has been shown to modulate the stability of cyclin B1, a cell cycle regulator. However, the function of Hip2 in gastric cancer (GC) remains largely elusive. Methods The expression of Hip2 in GC cell lines was analyzed by RT-qPCR, Western Blotting and Immunohistochemical Staining. shRNA was utilized to knock down the expression of Hip2. Cell growth, cell cycle, migration, invasion and tumorigenesis were performed by CCK-8, BrdU staining, flow cytometry, wound healing, transwell migration and invasion, and xenograft assay, respectively. Results Hip2 was highly expressed in GC cell lines and patients. High level of Hip2 indicated poor prognosis. Knockdown of Hip2 suppressed cell growth, lead to G2/M phase arrest, and reduced cell migration and invasion in vitro. Furthermore, downregulation of Hip2 inhibited tumorigenesis in vivo. Conclusions Elevated expression of HIP2 in GC patients suggested poor prognosis. Reduction of Hip2 suppressed GC progression, indicating that Hip2 may be a potential target for the management of GC.
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Affiliation(s)
- Jugang Wu
- Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Baoxing Tian
- Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Jianjun Yang
- Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Haizhong Huo
- Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Zhicheng Song
- Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Jiwei Yu
- Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Yan Gu
- Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
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35
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Abstract
Polyglutamine (polyQ) disease is a type of fatal neurodegenerative disease caused by an expansion of CAG repeats in a specific gene, resulting in a protein with an abnormal polyQ fragment. The age of onset and the degree of pathological deterioration are related to the length of the polyQ fragment. At least 9 kinds of polyglutamine diseases have been discovered, including Huntington disease (HD), dentatorubral pallidoluysian atrophy (DRPLA), spinobulbar muscular atrophy (SBMA) and six spinocerebellar ataxia (SCA) such as SCA1, 2, 3, 6, 7 and 17 subtypes (Table 9.1). Previous studies suggest that autophagy plays a major role in the quality control of disease proteins in polyQ diseases. In this chapter, we majorly focused on three representative polyQ diseases, including spinocerebellar Ataxia type 3 (SCA3), spinocerebellar ataxia type 7 (SCA7) and Huntington's disease (HD). The relationship of the ubiquitin-proteasome system and autophagy involved in disease protein accumulation were summarized.
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36
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Tomita T, Matouschek A. Substrate selection by the proteasome through initiation regions. Protein Sci 2019; 28:1222-1232. [PMID: 31074920 DOI: 10.1002/pro.3642] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/03/2019] [Accepted: 05/06/2019] [Indexed: 01/04/2023]
Abstract
Proteins in the cell have to be eliminated once their function is no longer desired or they become damaged. Most regulated protein degradation is achieved by a large enzymatic complex called the proteasome. Many proteasome substrates are targeted for degradation by the covalent attachment of ubiquitin molecules. Ubiquitinated proteins can be bound by the proteasome, but for proteolysis to occur the proteasome needs to find a disordered tail somewhere in the target at which it initiates degradation. The initiation step contributes to the specificity of proteasomal degradation. Here, we review how the proteasome selects initiation sites within its substrates and discuss how the initiation step affects physiological processes.
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Affiliation(s)
- Takuya Tomita
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, 78712
| | - Andreas Matouschek
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, 78712
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37
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Illarioshkin SN, Klyushnikov SA, Vigont VA, Seliverstov YA, Kaznacheyeva EV. Molecular Pathogenesis in Huntington's Disease. BIOCHEMISTRY (MOSCOW) 2018; 83:1030-1039. [PMID: 30472941 DOI: 10.1134/s0006297918090043] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Huntington's disease (HD) is a severe autosomal dominant neurodegenerative disorder characterized by a combination of motor, cognitive, and psychiatric symptoms, atrophy of the basal ganglia and the cerebral cortex, and inevitably progressive course resulting in death 5-20 years after manifestation of its symptoms. HD is caused by expansion of CAG repeats in the HTT gene, which leads to pathological elongation of the polyglutamine tract within the respective protein - huntingtin. In this review, we present a modern view on molecular biology of HD as a representative of the group of polyglutamine diseases, with an emphasis on conformational changes of mutant huntingtin, disturbances in its cellular processing, and proteolytic stress in degenerating neurons. Main pathogenetic mechanisms of neurodegeneration in HD are discussed in detail, such as systemic failure of transcription, mitochondrial dysfunction and suppression of energy metabolism, abnormalities of cytoskeleton and axonal transport, microglial inflammation, decrease in synthesis of brain-derived neurotrophic factor, etc.
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Affiliation(s)
| | - S A Klyushnikov
- Research Center of Neurology, Moscow, 125367, Russia.,Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia
| | - V A Vigont
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia.
| | | | - E V Kaznacheyeva
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia.
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38
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Lee JG, Youn HS, Kang JY, Park SY, Kidera A, Yoo YJ, Eom SH. Crystal structure of the Ube2K/E2-25K and K48-linked di-ubiquitin complex provides structural insight into the mechanism of K48-specific ubiquitin chain synthesis. Biochem Biophys Res Commun 2018; 506:102-107. [DOI: 10.1016/j.bbrc.2018.10.067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 10/10/2018] [Indexed: 02/08/2023]
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39
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Reduction of HIP2 expression causes motor function impairment and increased vulnerability to dopaminergic degeneration in Parkinson's disease models. Cell Death Dis 2018; 9:1020. [PMID: 30282965 PMCID: PMC6170399 DOI: 10.1038/s41419-018-1066-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 08/29/2018] [Accepted: 09/10/2018] [Indexed: 11/08/2022]
Abstract
Huntingtin interaction protein 2 (HIP2) is an E2 ubiquitin-conjugating enzyme associated with neurodegenerative diseases, and HIP2 mRNA has been implicated as a potential blood biomarker for Parkinson's disease (PD). However, it is unclear whether the alteration of HIP2 expression may contribute to the development of PD, and whether the change of HIP2 in blood could reflect its expression in the brain or motor functions in PD patients. In this study, we established a mouse line with HIP2 haploinsufficiency. The reduction of the HIP2 expression led to spontaneous motor function impairment and dopaminergic neuronal loss. Furthermore, HIP2 haploinsufficiency increased the susceptibility of mice to 6-hydroxydopamine (6-OHDA) and caused severe loss of dopaminergic neurons. Interestingly, in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model for PD, we observed concurrent, highly correlated decrease of HIP2 expression in the brain and in the blood. Using blood samples from more than 300 patients, we validated the decreased HIP2 mRNA in PD patients, including de novo patients. Finally, in a 1-year, 20-patient study, we observed reversed blood HIP2 mRNA levels accompanying improved motor and overall daily functions in 75% of the PD patients with instructed Tai Chi training. Therefore, our in vivo studies have indicated HIP2 insufficiency as a contributing factor for PD, and functionally validated blood HIP2 as a useful and reversible biomarker for PD.
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Abstract
The 25 years since the identification of the gene responsible for Huntington disease (HD) have stood witness to profound discoveries about the nature of the disease and its pathogenesis. Despite this progress, however, the development of disease-modifying therapies has thus far been slow. Preclinical validation of the therapeutic potential of disrupted pathways in HD has led to the advancement of pharmacological agents, both novel and repurposed, for clinical evaluation. The most promising therapeutic approaches include huntingtin (HTT) lowering and modification as well as modulation of neuroinflammation and synaptic transmission. With clinical trials for many of these approaches imminent or currently ongoing, the coming years are promising not only for HD but also for more prevalent neurodegenerative disorders, such as Alzheimer and Parkinson disease, in which many of these pathways have been similarly implicated.
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The ubiquitin ligase UBR5 suppresses proteostasis collapse in pluripotent stem cells from Huntington's disease patients. Nat Commun 2018; 9:2886. [PMID: 30038412 PMCID: PMC6056416 DOI: 10.1038/s41467-018-05320-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 06/29/2018] [Indexed: 01/12/2023] Open
Abstract
Induced pluripotent stem cells (iPSCs) undergo unlimited self-renewal while maintaining their potential to differentiate into post-mitotic cells with an intact proteome. As such, iPSCs suppress the aggregation of polyQ-expanded huntingtin (HTT), the mutant protein underlying Huntington’s disease (HD). Here we show that proteasome activity determines HTT levels, preventing polyQ-expanded aggregation in iPSCs from HD patients (HD-iPSCs). iPSCs exhibit high levels of UBR5, a ubiquitin ligase required for proteasomal degradation of both normal and mutant HTT. Conversely, loss of UBR5 increases HTT levels and triggers polyQ-expanded aggregation in HD-iPSCs. Moreover, UBR5 knockdown hastens polyQ-expanded aggregation and neurotoxicity in invertebrate models. Notably, UBR5 overexpression induces polyubiquitination and degradation of mutant HTT, reducing polyQ-expanded aggregates in HD-cell models. Besides HTT levels, intrinsic enhanced UBR5 expression determines global proteostasis of iPSCs preventing the aggregation of misfolded proteins ensued from normal metabolism. Thus, our findings indicate UBR5 as a modulator of super-vigilant proteostasis of iPSCs. Induced pluripotent stem cells (iPSCs) suppress the aggregation of Huntington’s disease (HD) polyQ-expanded huntingtin (HTT). Here the authors show that proteasome activity determines the levels of mutant HTT in HD-iPSCs and find that UBR5 is a modulator of super-vigilant proteostasis of iPSCs.
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Active Site Gate Dynamics Modulate the Catalytic Activity of the Ubiquitination Enzyme E2-25K. Sci Rep 2018; 8:7002. [PMID: 29725124 PMCID: PMC5934386 DOI: 10.1038/s41598-018-25476-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/23/2018] [Indexed: 12/13/2022] Open
Abstract
The ubiquitin proteasome system (UPS) signals for degradation of proteins through attachment of K48-linked polyubiquitin chains, or alterations in protein-protein recognition through attachment of K63-linked chains. Target proteins are ubiquitinated in three sequential chemical steps by a three-component enzyme system. Ubiquitination, or E2 enzymes, catalyze the central step by facilitating reaction of a target protein lysine with the C-terminus of Ub that is attached to the active site cysteine of the E2 through a thioester bond. E2 reactivity is modulated by dynamics of an active site gate, whose central residue packs against the active site cysteine in a closed conformation. Interestingly, for the E2 Ubc13, which specifically catalyzes K63-linked ubiquitination, the central gate residue adopts an open conformation. We set out to determine if active site gate dynamics play a role in catalysis for E2-25K, which adopts the canonical, closed gate conformation, and which selectively synthesizes K48-linked ubiquitin chains. Gate dynamics were characterized using mutagenesis of key residues, combined with enzyme kinetics measurements, and main chain NMR relaxation. The experimental data were interpreted with all atom MD simulations. The data indicate that active site gate opening and closing rates for E2-25K are precisely balanced.
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Ehrnhoefer DE, Martin DDO, Schmidt ME, Qiu X, Ladha S, Caron NS, Skotte NH, Nguyen YTN, Vaid K, Southwell AL, Engemann S, Franciosi S, Hayden MR. Preventing mutant huntingtin proteolysis and intermittent fasting promote autophagy in models of Huntington disease. Acta Neuropathol Commun 2018; 6:16. [PMID: 29510748 PMCID: PMC5839066 DOI: 10.1186/s40478-018-0518-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 02/12/2018] [Indexed: 12/20/2022] Open
Abstract
Huntington disease (HD) is caused by the expression of mutant huntingtin (mHTT) bearing a polyglutamine expansion. In HD, mHTT accumulation is accompanied by a dysfunction in basal autophagy, which manifests as specific defects in cargo loading during selective autophagy. Here we show that the expression of mHTT resistant to proteolysis at the caspase cleavage site D586 (C6R mHTT) increases autophagy, which may be due to its increased binding to the autophagy adapter p62. This is accompanied by faster degradation of C6R mHTT in vitro and a lack of mHTT accumulation the C6R mouse model with age. These findings may explain the previously observed neuroprotective properties of C6R mHTT. As the C6R mutation cannot be easily translated into a therapeutic approach, we show that a scheduled feeding paradigm is sufficient to lower mHTT levels in YAC128 mice expressing cleavable mHTT. This is consistent with a previous model, where the presence of cleavable mHTT impairs basal autophagy, while fasting-induced autophagy remains functional. In HD, mHTT clearance and autophagy may become increasingly impaired as a function of age and disease stage, because of gradually increased activity of mHTT-processing enzymes. Our findings imply that mHTT clearance could be enhanced by a regulated dietary schedule that promotes autophagy.
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Neuronal Proteomic Analysis of the Ubiquitinated Substrates of the Disease-Linked E3 Ligases Parkin and Ube3a. BIOMED RESEARCH INTERNATIONAL 2018; 2018:3180413. [PMID: 29693004 PMCID: PMC5859835 DOI: 10.1155/2018/3180413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/15/2018] [Indexed: 01/09/2023]
Abstract
Both Parkin and UBE3A are E3 ubiquitin ligases whose mutations result in severe brain dysfunction. Several of their substrates have been identified using cell culture models in combination with proteasome inhibitors, but not in more physiological settings. We recently developed the bioUb strategy to isolate ubiquitinated proteins in flies and have now identified by mass spectrometry analysis the neuronal proteins differentially ubiquitinated by those ligases. This is an example of how flies can be used to provide biological material in order to reveal steady state substrates of disease causing genes. Collectively our results provide new leads to the possible physiological functions of the activity of those two disease causing E3 ligases. Particularly, in the case of Parkin the novelty of our data originates from the experimental setup, which is not overtly biased by acute mitochondrial depolarisation. In the case of UBE3A, it is the first time that a nonbiased screen for its neuronal substrates has been reported.
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Zhou L, Hao Z, Wang G, Xu G. Cereblon suppresses the formation of pathogenic protein aggregates in a p62-dependent manner. Hum Mol Genet 2017; 27:667-678. [DOI: 10.1093/hmg/ddx433] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/15/2017] [Indexed: 01/27/2023] Open
Affiliation(s)
- Liang Zhou
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Department of Pharmacology, College of Pharmaceutical Sciences, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu 215123, China
| | - Zongbing Hao
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Neuropsychiatric Diseases, Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Guanghui Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Neuropsychiatric Diseases, Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Guoqiang Xu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Department of Pharmacology, College of Pharmaceutical Sciences, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu 215123, China
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Graham SH, Liu H. Life and death in the trash heap: The ubiquitin proteasome pathway and UCHL1 in brain aging, neurodegenerative disease and cerebral Ischemia. Ageing Res Rev 2017; 34:30-38. [PMID: 27702698 DOI: 10.1016/j.arr.2016.09.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/08/2016] [Accepted: 09/29/2016] [Indexed: 12/11/2022]
Abstract
The ubiquitin proteasome pathway (UPP) is essential for removing abnormal proteins and preventing accumulation of potentially toxic proteins within the neuron. UPP dysfunction occurs with normal aging and is associated with abnormal accumulation of protein aggregates within neurons in neurodegenerative diseases. Ischemia disrupts UPP function and thus may contribute to UPP dysfunction seen in the aging brain and in neurodegenerative diseases. Ubiquitin carboxy-terminal hydrolase L1 (UCHL1), an important component of the UPP in the neuron, is covalently modified and its activity inhibited by reactive lipids produced after ischemia. As a result, degradation of toxic proteins is impaired which may exacerbate neuronal function and cell death in stroke and neurodegenerative diseases. Preserving or restoring UCHL1 activity may be an effective therapeutic strategy in stroke and neurodegenerative diseases.
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Adegbuyiro A, Sedighi F, Pilkington AW, Groover S, Legleiter J. Proteins Containing Expanded Polyglutamine Tracts and Neurodegenerative Disease. Biochemistry 2017; 56:1199-1217. [PMID: 28170216 DOI: 10.1021/acs.biochem.6b00936] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Several hereditary neurological and neuromuscular diseases are caused by an abnormal expansion of trinucleotide repeats. To date, there have been 10 of these trinucleotide repeat disorders associated with an expansion of the codon CAG encoding glutamine (Q). For these polyglutamine (polyQ) diseases, there is a critical threshold length of the CAG repeat required for disease, and further expansion beyond this threshold is correlated with age of onset and symptom severity. PolyQ expansion in the translated proteins promotes their self-assembly into a variety of oligomeric and fibrillar aggregate species that accumulate into the hallmark proteinaceous inclusion bodies associated with each disease. Here, we review aggregation mechanisms of proteins with expanded polyQ-tracts, structural consequences of expanded polyQ ranging from monomers to fibrillar aggregates, the impact of protein context and post-translational modifications on aggregation, and a potential role for lipid membranes in aggregation. As the pathogenic mechanisms that underlie these disorders are often classified as either a gain of toxic function or loss of normal protein function, some toxic mechanisms associated with mutant polyQ tracts will also be discussed.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Albert W Pilkington
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States.,Blanchette Rockefeller Neurosciences Institute, Robert C. Byrd Health Sciences Center, P.O. Box 9304, West Virginia University , Morgantown, West Virginia 26506, United States.,NanoSAFE, P.O. Box 6223, West Virginia University , Morgantown, West Virginia 26506, United States
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Cheng MC, Kuo WC, Wang YM, Chen HY, Lin TP. UBC18 mediates ERF1 degradation under light-dark cycles. THE NEW PHYTOLOGIST 2017; 213:1156-1167. [PMID: 27787902 DOI: 10.1111/nph.14272] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/11/2016] [Indexed: 05/05/2023]
Abstract
Ethylene Response Factor 1 (ERF1) plays a crucial role in biotic and abiotic stress responses. Previous studies have shown that ERF1 regulates stress-responsive gene expression by binding to different cis-acting elements in response to various stress signals. ERF1 was also reported to be unstable in the dark, and it regulates hypocotyl elongation. Here, we elucidated the mechanism underlying degradation of ERF1. Yeast two-hybrid screening showed that UBIQUITIN-CONJUGATING ENZYME 18 (UBC18) interacted with ERF1. The interaction between ERF1 and UBC18 was verified using pull-down assays and coimmunoprecipitation analyses. We then compared the ERF1 protein abundance in the UBC18 mutant and overexpression plants. Based on the results of protein degradation and in vivo ubiquitination assays, we proposed that UBC18 mediates ERF1 ubiquitination and degradation. ERF1 was more stable in UBC18 mutants and less stable in UBC18 overexpression lines compared with that in wild-type plants. ERF1 was degraded by the 26S proteasome system via regulation of UBC18 and promotes dark-repression of downstream genes and proline accumulation. UBC18 negatively regulated drought and salt stress responses by altering the abundance of ERF1 and the expression of genes downstream of ERF1.
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Affiliation(s)
- Mei-Chun Cheng
- Institute of Plant Biology, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei, 10617, Taiwan
| | - Wen-Chieh Kuo
- Institute of Plant Biology, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei, 10617, Taiwan
| | - Yi-Ming Wang
- Institute of Plant Biology, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei, 10617, Taiwan
| | - Hsing-Yu Chen
- Institute of Plant Biology, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei, 10617, Taiwan
| | - Tsan-Piao Lin
- Institute of Plant Biology, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei, 10617, Taiwan
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E2-25K SUMOylation inhibits proteasome for cell death during cerebral ischemia/reperfusion. Cell Death Dis 2016; 7:e2573. [PMID: 28032866 PMCID: PMC5261013 DOI: 10.1038/cddis.2016.428] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 01/12/2023]
Abstract
Cerebral ischemia/reperfusion (I/R) causes brain damage accompanied by ubiquitin accumulation and impairment of proteasome activity. In this study, we report that E2-25K, an E2-conjugating enzyme, is SUMOylated during oxidative stress and regulates cerebral I/R-induced damage. Knockdown of E2-25K expression protects against oxygen/glucose deprivation and reoxygenation (OGD/R)-induced neuronal cell death, whereas ectopic expression of E2-25K stimulates it. Compared with the control mice, cerebral infarction lesions and behavioral/neurological disorders are ameliorated in E2-25K knockout mice during middle cerebral artery occlusion and reperfusion. In particular, E2-25K is SUMOylated at Lys14 under oxidative stress, OGD/R and I/R to prompt cell death. Further, E2-25K downregulates the proteasome subunit S5a to impair proteasome complex and thus restrain proteasome activity under oxidative stress. This proteasome inhibitory activity of E2-25K is dependent on its SUMOylation. These results suggest that E2-25K has a crucial role in oxidative stress and cerebral I/R-induced damage through inhibiting proteasome via its SUMOylation.
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The Ubiquitin Receptor ADRM1 Modulates HAP40-Induced Proteasome Activity. Mol Neurobiol 2016; 54:7382-7400. [PMID: 27815841 DOI: 10.1007/s12035-016-0247-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/23/2016] [Indexed: 10/20/2022]
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder caused by an N-terminal expansion of polyglutamine stretch (polyQ) of huntingtin (Htt) protein. HAP40 is a huntingtin-associated protein with unknown cellular functions. Increased HAP40 expression has been reported in the brain of HD patients and HD mouse model. However, the relationship between the elevation of HAP40 and HD etiology remains elusive. In this study, we demonstrated that overexpression of HAP40 enhanced accumulation of mutant Htt aggregates and caused defects in proteasome function. Specifically, excess HAP40 interfered with adhesion-regulating molecule 1 (ADRM1), a proteasome ubiquitin receptor, to regulate the proteasome-dependent pathway. Increasing ADRM1 in the presence of excess HAP40 alleviated mutant Htt aggregates and at the same time, restored the cell viability. Reducing ADRM1 in the absence of excess HAP40; on the other hand, increased mutant Htt aggregates and decreased the cell viability. Our data provide compelling evidence to support that ADRM1 plays an important role in mediating removal of mutant Htt aggregates when excess HAP40 is present. ADRM1-dependent ubiquitin proteasome system (UPS) may be a general mechanism to guard cells from mutant Htt toxicity.
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