1
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Kahraman K, Robson SA, Göcenler O, Yenici CM, Tozkoparan Ceylan CD, Klein JM, Dötsch V, Elgin ES, Haas AL, Ziarek JJ, Dağ Ç. Characterizing the Monomer-Dimer Equilibrium of UbcH8/Ube2L6: A Combined SAXS and NMR Study. ACS OMEGA 2024; 9:39564-39572. [PMID: 39346869 PMCID: PMC11425648 DOI: 10.1021/acsomega.4c03610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 06/01/2024] [Accepted: 06/18/2024] [Indexed: 10/01/2024]
Abstract
Interferon-stimulated gene-15 (ISG15) is an interferon-induced protein with two ubiquitin-like (Ubl) domains linked by a short peptide chain and is a conjugated protein of the ISGylation system. Similar to ubiquitin and other Ubls, ISG15 is ligated to its target proteins through a series of E1, E2, and E3 enzymes known as Uba7, Ube2L6/UbcH8, and HERC5, respectively. Ube2L6/UbcH8 plays a central role in ISGylation, underscoring it as an important drug target for boosting innate antiviral immunity. Depending on the type of conjugated protein and the ultimate target protein, E2 enzymes have been shown to function as monomers, dimers, or both. UbcH8 has been crystallized in both monomeric and dimeric forms, but its functional state remains unclear. Here, we used a combined approach of small-angle X-ray scattering (SAXS) and nuclear magnetic resonance (NMR) spectroscopy to characterize UbcH8's oligomeric state in solution. SAXS revealed a dimeric UbcH8 structure that could be dissociated when fused N-terminally to glutathione S-transferase. NMR spectroscopy validated the presence of a concentration-dependent monomer-dimer equilibrium and suggested a back-side dimerization interface. Chemical shift perturbation and peak intensity analysis further suggest dimer-induced conformational dynamics at the E1 and E3 interfaces, providing hypotheses for the protein's functional mechanisms. Our study highlights the power of combining NMR and SAXS techniques to provide structural information about proteins in solution.
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Affiliation(s)
- Kerem Kahraman
- Nanofabrication
and Nanocharacterization Center for Scientific and Technological Advanced
Research (nSTAR), Koç
University, İstanbul 34450, Turkey
| | - Scott A. Robson
- Department
of Pharmacology, Feinberg School of Medicine, Northwestern University, 320 East Superior Avenue, Chicago, Illinois 460611, United States
| | - Oktay Göcenler
- Nanofabrication
and Nanocharacterization Center for Scientific and Technological Advanced
Research (nSTAR), Koç
University, İstanbul 34450, Turkey
| | - Cansu M. Yenici
- Nanofabrication
and Nanocharacterization Center for Scientific and Technological Advanced
Research (nSTAR), Koç
University, İstanbul 34450, Turkey
| | - Cansu D. Tozkoparan Ceylan
- Nanofabrication
and Nanocharacterization Center for Scientific and Technological Advanced
Research (nSTAR), Koç
University, İstanbul 34450, Turkey
| | - Jennifer M. Klein
- Department
of Biochemistry and Molecular Biology, LSUHSC-School
of Medicine, 1901 Perdido Street, New Orleans, Louisiana 70112, United States
| | - Volker Dötsch
- Centre
for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe-University of Frankfurt/Main, Frankfurt 60439, Germany
| | - Emine Sonay Elgin
- College
of Sciences, Department of Chemistry, Muğla
Sıtkı Koçman University, Muğla 48000, Turkey
| | - Arthur L. Haas
- Department
of Biochemistry and Molecular Biology, LSUHSC-School
of Medicine, 1901 Perdido Street, New Orleans, Louisiana 70112, United States
| | - Joshua J. Ziarek
- Department
of Pharmacology, Feinberg School of Medicine, Northwestern University, 320 East Superior Avenue, Chicago, Illinois 460611, United States
| | - Çağdaş Dağ
- Nanofabrication
and Nanocharacterization Center for Scientific and Technological Advanced
Research (nSTAR), Koç
University, İstanbul 34450, Turkey
- Koç
University Isbank Center for Infectious Diseases (KUISCID), Koç
University, Istanbul 34450, Turkey
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2
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Kahraman K, Robson SA, Göcenler O, Yenici CM, Tozkoparan CD, Klein JM, Dötsch V, Elgin ES, Haas AL, Ziarek JJ, Dağ Ç. Characterizing the monomer-dimer equilibrium of UbcH8/Ube2L6: A combined SAXS and NMR study. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.13.536743. [PMID: 37090523 PMCID: PMC10120734 DOI: 10.1101/2023.04.13.536743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Interferon-stimulated gene-15 (ISG15) is an interferon-induced protein with two ubiquitin-like (Ubl) domains linked by a short peptide chain, and the conjugated protein of the ISGylation system. Similar to ubiquitin and other Ubls, ISG15 is ligated to its target proteins through a series of E1, E2, and E3 enzymes known as Uba7, Ube2L6/UbcH8, and HERC5, respectively. Ube2L6/UbcH8 plays a literal central role in ISGylation, underscoring it as an important drug target for boosting innate antiviral immunity. Depending on the type of conjugated protein and the ultimate target protein, E2 enzymes have been shown to function as monomers, dimers, or both. UbcH8 has been crystalized in both monomeric and dimeric forms, but the functional state is unclear. Here, we used a combined approach of small-angle X-ray scattering (SAXS) and nuclear magnetic resonance (NMR) spectroscopy to characterize UbcH8's oligomeric state in solution. SAXS revealed a dimeric UbcH8 structure that could be dissociated when fused N-terminally to glutathione S-transferase. NMR spectroscopy validated the presence of a concentration-dependent monomer-dimer equilibrium and suggested a backside dimerization interface. Chemical shift perturbation and peak intensity analysis further suggest dimer-induced conformational dynamics at E1 and E3 interfaces - providing hypotheses for the protein's functional mechanisms. Our study highlights the power of combining NMR and SAXS techniques in providing structural information about proteins in solution.
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Affiliation(s)
- Kerem Kahraman
- Nanofabrication and Nanocharacterization Center for Scientific and Technological Advanced Research (nSTAR), Koc University, İstanbul, Turkey
| | - Scott A. Robson
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, 320 East Superior Avenue, Chicago, IL, 460611, USA
| | - Oktay Göcenler
- Nanofabrication and Nanocharacterization Center for Scientific and Technological Advanced Research (nSTAR), Koc University, İstanbul, Turkey
| | - Cansu M. Yenici
- Nanofabrication and Nanocharacterization Center for Scientific and Technological Advanced Research (nSTAR), Koc University, İstanbul, Turkey
| | - Cansu D. Tozkoparan
- Nanofabrication and Nanocharacterization Center for Scientific and Technological Advanced Research (nSTAR), Koc University, İstanbul, Turkey
| | - Jennifer M. Klein
- Department of Biochemistry and Molecular Biology, LSUHSC-School of Medicine, 1901 Perdido Street, New Orleans, LA, 70112, USA
| | - Volker Dötsch
- Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe-University of Frankfurt/Main, Germany
| | - Emine Sonay Elgin
- Muğla Sıtkı Koçman University, College of Sciences, Department of Chemistry, Mugla, 48000, Turkey
| | - Arthur L. Haas
- Department of Biochemistry and Molecular Biology, LSUHSC-School of Medicine, 1901 Perdido Street, New Orleans, LA, 70112, USA
| | - Joshua J. Ziarek
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, 320 East Superior Avenue, Chicago, IL, 460611, USA
| | - Çağdaş Dağ
- Nanofabrication and Nanocharacterization Center for Scientific and Technological Advanced Research (nSTAR), Koc University, İstanbul, Turkey
- Koc University Isbank Center for Infectious Diseases (KUISCID), Koc University, Istanbul, Turkey
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3
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Huo Q, Hu J, Hou B, Zhao M, Han X, Du Y, Li Y. Clinicopathological Features and Prognostic Evaluation of UBR5 in Liver Cancer Patients. Pathol Oncol Res 2022; 28:1610396. [PMID: 36388433 PMCID: PMC9665233 DOI: 10.3389/pore.2022.1610396] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 10/11/2022] [Indexed: 06/28/2024]
Abstract
Background: Typically, liver cancer patients are diagnosed at an advanced stage and have a poor prognosis. N-recognin 5 (UBR5), a component of the ubiquitin protein ligase E3, is involved in the genesis and progression of several types of cancer. As of yet, it is unknown what the exact biological function of UBR5 is in liver cancer. Methods: A Kaplan-Meier survival curve (OS) was used to examine the effect of UBR5 expression on overall survival based on the TCGA database. To determine the molecular functions of UBR5 in liver cancer, we used the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. A protein-protein interaction (PPI) network was established for the screening of UBR5-related proteins in liver cancer. Western blot analysis was used to determine the expression levels of UBR5 and YWHAZ (tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta), and in order to detect cell proliferation, an MTT assay was used. Results: The expression of UBR5 in liver cancer patient samples is significantly higher than in adjacent normal tissues. A high level of UBR5 expression was associated with older patients, a higher tumor grade, lymph node metastasis, and poor survival. We discovered YWHAZ with high connectivity, and UBR5 expression correlated positively with YWHAZ expression (r = 0.83, p < 0.05). Furthermore, we found that elevated UBR5 levels directly correlated with YWHAZ overexpression, and that UBR5 promoted cell proliferation by affecting YWHAZ expression. Additionally, the TCGA databases confirmed that patients with liver cancer who expressed higher levels of YWHAZ had poorer outcomes. Conclusion: This suggests that UBR5 associated with YWHAZ may influence prognosis in patients with liver cancer, and that UBR5 may be a candidate treatment target for liver cancer. Therefore, UBR5 associated with YWHAZ may influence prognosis in patients with liver cancer, and UBR5 could serve as a potential target for liver cancer treatment.
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Affiliation(s)
- Qi Huo
- Department of Medical Oncology, The Second Affiliated Hospital of Bengbu Medical College, Bengbu, China
| | - Junjie Hu
- Department of Medical Oncology, The Second Affiliated Hospital of Bengbu Medical College, Bengbu, China
| | - Binfen Hou
- Anhui Provincial Key Laboratory of Immunology in Chronic Diseases, Anhui Provincial Key Laboratory of Infection and Immunology, Department of Laboratory Medicine, Bengbu Medical College, Bengbu, China
| | - Mei Zhao
- Department of Medical Oncology, The Second Affiliated Hospital of Bengbu Medical College, Bengbu, China
| | - Xue Han
- Anhui Provincial Key Laboratory of Immunology in Chronic Diseases, Anhui Provincial Key Laboratory of Infection and Immunology, Department of Laboratory Medicine, Bengbu Medical College, Bengbu, China
| | - Yulin Du
- Anhui Provincial Key Laboratory of Immunology in Chronic Diseases, Anhui Provincial Key Laboratory of Infection and Immunology, Department of Laboratory Medicine, Bengbu Medical College, Bengbu, China
| | - Yao Li
- Anhui Provincial Key Laboratory of Immunology in Chronic Diseases, Anhui Provincial Key Laboratory of Infection and Immunology, Department of Laboratory Medicine, Bengbu Medical College, Bengbu, China
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4
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Němec V, Schwalm MP, Müller S, Knapp S. PROTAC degraders as chemical probes for studying target biology and target validation. Chem Soc Rev 2022; 51:7971-7993. [PMID: 36004812 DOI: 10.1039/d2cs00478j] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Small molecule degraders such as PROTACs (PROteolysis TArgeting Chimeras) have emerged as new promising pharmacological modalities and the first PROTAC drug candidates are now studied clinically. The catalytic properties of PROTACs, acting as chemical degraders of a protein of interest (POI), represent an attractive new strategy for drug development. The development and characterization of PROTACs requires an array of additional assay systems that track the degradation pathway leading ultimately to degradation of the POI, identifying critical steps for PROTAC optimization. In addition to their exciting translational potential, PROTACs represent versatile chemical tools that considerably expanded our chemical biology toolbox and significantly enlarged the proteome that can be modulated by small molecules. Similar to conventional chemical probes, PROTACs used as chemical probes in target validation require comprehensive characterization. As a consequence, PROTAC-specific quality criteria should be defined by the chemical biology community. These criteria need to comprise additional or alternative parameters compared to those for conventional occupancy-driven chemical probes, such as the maximum level of target degradation (Dmax), confirmation of a proteasome dependent degradation mechanism and, importantly, also kinetic parameters of POI degradation. The kinetic aspects are particularly relevant for PROTACs that harbor covalent binding moieties. Here, we review recent progress in the development of assay systems for PROTAC characterization and suggest a set of criteria for PROTACs as high quality chemical probes.
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Affiliation(s)
- Václav Němec
- Institut für Pharmazeutische Chemie, Goethe-University Frankfurt, Biozentrum, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany. .,Structural Genomics Consortium, Goethe-University Frankfurt, Buchmann Institute for Life Sciences, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Martin P Schwalm
- Institut für Pharmazeutische Chemie, Goethe-University Frankfurt, Biozentrum, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany. .,Structural Genomics Consortium, Goethe-University Frankfurt, Buchmann Institute for Life Sciences, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Susanne Müller
- Institut für Pharmazeutische Chemie, Goethe-University Frankfurt, Biozentrum, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany. .,Structural Genomics Consortium, Goethe-University Frankfurt, Buchmann Institute for Life Sciences, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Stefan Knapp
- Institut für Pharmazeutische Chemie, Goethe-University Frankfurt, Biozentrum, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany. .,Structural Genomics Consortium, Goethe-University Frankfurt, Buchmann Institute for Life Sciences, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany.,German Cancer Consortium (DKTK)/German Cancer Research Center (DKFZ), DKTK site Frankfurt-Mainz, 69120 Heidelberg, Germany
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5
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Ubiquitin Ligase Redundancy and Nuclear-Cytoplasmic Localization in Yeast Protein Quality Control. Biomolecules 2021; 11:biom11121821. [PMID: 34944465 PMCID: PMC8698790 DOI: 10.3390/biom11121821] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 12/12/2022] Open
Abstract
The diverse functions of proteins depend on their proper three-dimensional folding and assembly. Misfolded cellular proteins can potentially harm cells by forming aggregates in their resident compartments that can interfere with vital cellular processes or sequester important factors. Protein quality control (PQC) pathways are responsible for the repair or destruction of these abnormal proteins. Most commonly, the ubiquitin-proteasome system (UPS) is employed to recognize and degrade those proteins that cannot be refolded by molecular chaperones. Misfolded substrates are ubiquitylated by a subset of ubiquitin ligases (also called E3s) that operate in different cellular compartments. Recent research in Saccharomyces cerevisiae has shown that the most prominent ligases mediating cytoplasmic and nuclear PQC have overlapping yet distinct substrate specificities. Many substrates have been characterized that can be targeted by more than one ubiquitin ligase depending on their localization, and cytoplasmic PQC substrates can be directed to the nucleus for ubiquitylation and degradation. Here, we review some of the major yeast PQC ubiquitin ligases operating in the nucleus and cytoplasm, as well as current evidence indicating how these ligases can often function redundantly toward substrates in these compartments.
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6
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Manzanza NDO, Sedlackova L, Kalaria RN. Alpha-Synuclein Post-translational Modifications: Implications for Pathogenesis of Lewy Body Disorders. Front Aging Neurosci 2021; 13:690293. [PMID: 34248606 PMCID: PMC8267936 DOI: 10.3389/fnagi.2021.690293] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/24/2021] [Indexed: 12/16/2022] Open
Abstract
Lewy Body Disorders (LBDs) lie within the spectrum of age-related neurodegenerative diseases now frequently categorized as the synucleinopathies. LBDs are considered to be among the second most common form of neurodegenerative dementias after Alzheimer's disease. They are progressive conditions with variable clinical symptoms embodied within specific cognitive and behavioral disorders. There are currently no effective treatments for LBDs. LBDs are histopathologically characterized by the presence of abnormal neuronal inclusions commonly known as Lewy Bodies (LBs) and extracellular Lewy Neurites (LNs). The inclusions predominantly comprise aggregates of alpha-synuclein (aSyn). It has been proposed that post-translational modifications (PTMs) such as aSyn phosphorylation, ubiquitination SUMOylation, Nitration, o-GlcNacylation, and Truncation play important roles in the formation of toxic forms of the protein, which consequently facilitates the formation of these inclusions. This review focuses on the role of different PTMs in aSyn in the pathogenesis of LBDs. We highlight how these PTMs interact with aSyn to promote misfolding and aggregation and interplay with cell membranes leading to the potential functional and pathogenic consequences detected so far, and their involvement in the development of LBDs.
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Affiliation(s)
- Nelson de Oliveira Manzanza
- Translational and Clinical Research Institute, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Lucia Sedlackova
- Biosciences Institute, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Raj N. Kalaria
- Translational and Clinical Research Institute, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
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7
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Blount JR, Johnson SL, Todi SV. Unanchored Ubiquitin Chains, Revisited. Front Cell Dev Biol 2020; 8:582361. [PMID: 33195227 PMCID: PMC7659471 DOI: 10.3389/fcell.2020.582361] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/15/2020] [Indexed: 12/20/2022] Open
Abstract
The small modifier protein, ubiquitin, holds a special place in eukaryotic biology because of its myriad post-translational effects that control normal cellular processes and are implicated in various diseases. By being covalently conjugated onto other proteins, ubiquitin changes their interaction landscape - fostering new interactions as well as inhibiting others - and ultimately deciding the fate of its substrates and controlling pathways that span most cell physiology. Ubiquitin can be attached onto other proteins as a monomer or as a poly-ubiquitin chain of diverse structural topologies. Among the types of poly-ubiquitin species generated are ones detached from another substrate - comprising solely ubiquitin as their constituent - referred to as unanchored, or free chains. Considered to be toxic byproducts, these species have recently emerged to have specific physiological functions in immune pathways and during cell stress. Free chains also do not appear to be detrimental to multi-cellular organisms; they can be active members of the ubiquitination process, rather than corollary species awaiting disassembly into mono-ubiquitin. Here, we summarize past and recent studies on unanchored ubiquitin chains, paying special attention to their emerging roles as second messengers in several signaling pathways. These investigations paint complex and flexible outcomes for free ubiquitin chains, and present a revised model of unanchored poly-ubiquitin biology that is in need of additional investigation.
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Affiliation(s)
- Jessica R Blount
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Sean L Johnson
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Sokol V Todi
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States.,Department of Neurology, Wayne State University School of Medicine, Detroit, MI, United States
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8
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Liess AKL, Kucerova A, Schweimer K, Schlesinger D, Dybkov O, Urlaub H, Mansfeld J, Lorenz S. Dimerization regulates the human APC/C-associated ubiquitin-conjugating enzyme UBE2S. Sci Signal 2020; 13:eaba8208. [PMID: 33082289 PMCID: PMC7613103 DOI: 10.1126/scisignal.aba8208] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
At the heart of protein ubiquitination cascades, ubiquitin-conjugating enzymes (E2s) form reactive ubiquitin-thioester intermediates to enable efficient transfer of ubiquitin to cellular substrates. The precise regulation of E2s is thus crucial for cellular homeostasis, and their deregulation is frequently associated with tumorigenesis. In addition to driving substrate ubiquitination together with ubiquitin ligases (E3s), many E2s can also autoubiquitinate, thereby promoting their own proteasomal turnover. To investigate the mechanisms that balance these disparate activities, we dissected the regulatory dynamics of UBE2S, a human APC/C-associated E2 that ensures the faithful ubiquitination of cell cycle regulators during mitosis. We uncovered a dimeric state of UBE2S that confers autoinhibition by blocking a catalytically critical ubiquitin binding site. Dimerization is stimulated by the lysine-rich carboxyl-terminal extension of UBE2S that is also required for the recruitment of this E2 to the APC/C and is autoubiquitinated as substrate abundance becomes limiting. Consistent with this mechanism, we found that dimerization-deficient UBE2S turned over more rapidly in cells and did not promote mitotic slippage during prolonged drug-induced mitotic arrest. We propose that dimerization attenuates the autoubiquitination-induced turnover of UBE2S when the APC/C is not fully active. More broadly, our data illustrate how the use of mutually exclusive macromolecular interfaces enables modulation of both the activities and the abundance of E2s in cells to facilitate precise ubiquitin signaling.
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Affiliation(s)
- Anna K L Liess
- Rudolf Virchow Center for Integrative and Translational Bioimaging, University of Würzburg, 97080 Würzburg, Germany
| | - Alena Kucerova
- Cell Cycle, Biotechnology Center, Technische Universität Dresden, 01307 Dresden, Germany
| | | | - Dörte Schlesinger
- Cell Cycle, Biotechnology Center, Technische Universität Dresden, 01307 Dresden, Germany
| | - Olexandr Dybkov
- Department for Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, 37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, 37077 Göttingen, Germany
- Bioanalytics Institute for Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Jörg Mansfeld
- Cell Cycle, Biotechnology Center, Technische Universität Dresden, 01307 Dresden, Germany.
- Institute of Cancer Research, London SW7 3RP, UK
| | - Sonja Lorenz
- Rudolf Virchow Center for Integrative and Translational Bioimaging, University of Würzburg, 97080 Würzburg, Germany.
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9
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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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10
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Guan H, Fu J, Yu T, Wang Z, Gan N, Huang Y, Perčulija V, Li Y, Luo Z, Ouyang S. Molecular Basis of Ubiquitination Catalyzed by the Bacterial Transglutaminase MavC. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2000871. [PMID: 32596129 PMCID: PMC7312448 DOI: 10.1002/advs.202000871] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/24/2020] [Indexed: 05/14/2023]
Abstract
The Legionella pneumophila effector MavC is a transglutaminase that carries out atypical ubiquitination of the host ubiquitin (Ub)-conjugation enzyme UBE2N by catalyzing the formation of an isopeptide bond between Gln40Ub and Lys92UBE2N, which leads to inhibition of signaling in the NF-κB pathway. In the absence of UBE2N, MavC deamidates Ub at Gln40 or catalyzes self-ubiquitination. However, the mechanisms underlying these enzymatic activities of MavC are poorly understood at the molecular level. This study reports the structure of the MavC-UBE2N-Ub ternary complex representing a snapshot of MavC-catalyzed crosslinking of UBE2N and Ub, which reveals the way by which UBE2N-Ub binds to the Insertion and Tail domains of MavC. Based on the structural and experimental data, the catalytic mechanism for the deamidase and transglutaminase activities of MavC is proposed. Finally, by comparing the structures of MavC and MvcA, the homologous protein that reverses MavC-induced UBE2N ubiquitination, several essential regions and two key residues (Trp255MavC and Phe268MvcA) responsible for their respective enzymatic activities are identified. The results provide insights into the mechanisms for substrate recognition and ubiquitination mediated by MavC as well as explanations for the opposite activity of MavC and MvcA in terms of regulation of UBE2N ubiquitination.
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Affiliation(s)
- Hongxin Guan
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao266237China
| | - Jiaqi Fu
- Purdue Institute for InflammationImmunology and Infectious Disease and Department of Biological SciencesPurdue UniversityWest LafayetteIN47907USA
| | - Ting Yu
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao266237China
| | - Zhao‐Xi Wang
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao266237China
| | - Ninghai Gan
- Purdue Institute for InflammationImmunology and Infectious Disease and Department of Biological SciencesPurdue UniversityWest LafayetteIN47907USA
| | - Yini Huang
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao266237China
| | - Vanja Perčulija
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
| | - Yu Li
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao266237China
| | - Zhao‐Qing Luo
- Purdue Institute for InflammationImmunology and Infectious Disease and Department of Biological SciencesPurdue UniversityWest LafayetteIN47907USA
| | - Songying Ouyang
- The Key Laboratory of Innate Immune Biology of Fujian ProvinceProvincial University Key Laboratory of Cellular Stress Response and Metabolic RegulationBiomedical Research Center of South ChinaKey Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of EducationCollege of Life SciencesFujian Normal UniversityFuzhou350117China
- Laboratory for Marine Biology and BiotechnologyPilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao266237China
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11
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Cook BW, Lacoursiere RE, Shaw GS. Recruitment of Ubiquitin within an E2 Chain Elongation Complex. Biophys J 2020; 118:1679-1689. [PMID: 32101714 DOI: 10.1016/j.bpj.2020.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/06/2020] [Accepted: 02/11/2020] [Indexed: 12/26/2022] Open
Abstract
The ubiquitin (Ub) proteolysis pathway uses an E1, E2, and E3 enzyme cascade to label substrate proteins with ubiquitin and target them for degradation. The mechanisms of ubiquitin chain formation remain unclear and include a sequential addition model, in which polyubiquitin chains are built unit by unit on the substrate, or a preassembly model, in which polyubiquitin chains are preformed on the E2 or E3 enzyme and then transferred in one step to the substrate. The E2 conjugating enzyme UBE2K has a 150-residue catalytic core domain and a C-terminal ubiquitin-associated (UBA) domain. Polyubiquitin chains anchored to the catalytic cysteine and free in solution are formed by UBE2K supporting a preassembly model. To study how UBE2K might assemble polyubiquitin chains, we synthesized UBE2K-Ub and UBE2K-Ub2 covalent complexes and analyzed E2 interactions with the covalently attached Ub and Ub2 moieties using NMR spectroscopy. The UBE2K-Ub complex exists in multiple conformations, including the catalytically competent closed state independent of the UBA domain. In contrast, the UBE2K-Ub2 complex takes on a more extended conformation directed by interactions between the classic I44 hydrophobic face of the distal Ub and the conserved MGF hydrophobic patch of the UBA domain. Our results indicate there are distinct differences between the UBE2K-Ub and UBE2K-Ub2 complexes and show how the UBA domain can alter the position of a polyubiquitin chain attached to the UBE2K active site. These observations provide structural insights into the unique Ub chain-building capacity for UBE2K.
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Affiliation(s)
- Benjamin W Cook
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Rachel E Lacoursiere
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Gary S Shaw
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada.
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12
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Kwon D, Kim SM, Correia MA. Cytochrome P450 endoplasmic reticulum-associated degradation (ERAD): therapeutic and pathophysiological implications. Acta Pharm Sin B 2020; 10:42-60. [PMID: 31993306 PMCID: PMC6976991 DOI: 10.1016/j.apsb.2019.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 02/07/2023] Open
Abstract
The hepatic endoplasmic reticulum (ER)-anchored cytochromes P450 (P450s) are mixed-function oxidases engaged in the biotransformation of physiologically relevant endobiotics as well as of myriad xenobiotics of therapeutic and environmental relevance. P450 ER-content and hence function is regulated by their coordinated hemoprotein syntheses and proteolytic turnover. Such P450 proteolytic turnover occurs through a process known as ER-associated degradation (ERAD) that involves ubiquitin-dependent proteasomal degradation (UPD) and/or autophagic-lysosomal degradation (ALD). Herein, on the basis of available literature reports and our own recent findings of in vitro as well as in vivo experimental studies, we discuss the therapeutic and pathophysiological implications of altered P450 ERAD and its plausible clinical relevance. We specifically (i) describe the P450 ERAD-machinery and how it may be repurposed for the generation of antigenic P450 peptides involved in P450 autoantibody pathogenesis in drug-induced acute hypersensitivity reactions and liver injury, or viral hepatitis; (ii) discuss the relevance of accelerated or disrupted P450-ERAD to the pharmacological and/or toxicological effects of clinically relevant P450 drug substrates; and (iii) detail the pathophysiological consequences of disrupted P450 ERAD, contributing to non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) under certain synergistic cellular conditions.
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Key Words
- 3MA, 3-methyladenine
- AAA, ATPases associated with various cellular activities
- ACC1, acetyl-CoA carboxylase 1
- ACC2, acetyl-CoA carboxylase 2
- ACHE, acetylcholinesterase
- ACOX1, acyl-CoA oxidase 1
- ALD, autophagic-lysosomal degradation
- AMPK1
- AP-1, activator protein 1
- ASK1, apoptosis signal-regulating kinase
- ATF2, activating transcription factor 2
- AdipoR1, gene of adiponectin receptor 1
- Atg14, autophagy-related 14
- CBZ, carbamazepine
- CHIP E3 ubiquitin ligase
- CHIP, carboxy-terminus of Hsc70-interacting protein
- Cytochromes P450
- Endoplasmic reticulum-associated degradation
- FOXO, forkhead box O
- Fas, fatty acid synthase
- GAPDH, glyceraldehyde 3-phosphate dehydrogenase
- INH, isoniazid
- IRS1, insulin receptor substrate 1
- Il-1β, interleukin 1 β
- Il-6, interleukin 6
- Insig1, insulin-induced gene 1
- JNK1
- Lpl, lipoprotein lipase
- Mcp1, chemokine (C–C motif) ligand 1
- Non-alcoholic fatty liver disease
- Non-alcoholic steatohepatitis
- Pgc1, peroxisome proliferator-activated receptor coactivator 1
- SREBP1c, sterol regulatory element binding transcription factor 1c
- Scd1, stearoyl-coenzyme A desaturase
- Tnf, tumor necrosis factor
- UPD, ubiquitin (Ub)-dependent proteasomal degradation
- Ub, ubiquitin
- gp78/AMFR E3 ubiquitin ligase
- gp78/AMFR, autocrine motility factor receptor
- shRNAi, shRNA interference
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13
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Kwon D, Kim SM, Jacob P, Liu Y, Correia MA. Induction via Functional Protein Stabilization of Hepatic Cytochromes P450 upon gp78/Autocrine Motility Factor Receptor (AMFR) Ubiquitin E3-Ligase Genetic Ablation in Mice: Therapeutic and Toxicological Relevance. Mol Pharmacol 2019; 96:641-654. [PMID: 31492698 DOI: 10.1124/mol.119.117069] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/22/2019] [Indexed: 02/06/2023] Open
Abstract
The hepatic endoplasmic reticulum (ER)-anchored monotopic proteins, cytochromes P450 (P450s), are enzymes that metabolize endobiotics (physiologically active steroids and fatty acids), as well as xenobiotics including therapeutic/chemotherapeutic drugs, nutrients, carcinogens, and toxins. Alterations of hepatic P450 content through synthesis, inactivation, or proteolytic turnover influence their metabolic function. P450 proteolytic turnover occurs via ER-associated degradation (ERAD) involving ubiquitin (Ub)-dependent proteasomal degradation (UPD) as a major pathway. UPD critically involves P450 protein ubiquitination by E2/E3 Ub-ligase complexes. We have previously identified the ER-polytopic gp78/AMFR (autocrine motility factor receptor) as a relevant E3 in CYP3A4, CYP3A23, and CYP2E1 UPD. We now document that liver-conditional genetic ablation of gp78/AMFR in male mice disrupts P450 ERAD, resulting in statistically significant stabilization of Cyp2a5 and Cyp2c, in addition to that of Cyp3a and Cyp2e1. More importantly, we establish that such stabilization is of the functionally active P450 proteins, leading to corresponding statistically significant enhancement of their drug-metabolizing capacities. Our findings, with clinically relevant therapeutic drugs (nicotine, coumarin, chlorzoxazone, and acetaminophen) and the prodrug (tamoxifen) as P450 substrates, reveal that P450 ERAD disruption could influence therapeutic drug response and/or toxicity, warranting serious consideration as a potential source of clinically relevant drug-drug interactions (DDIs). Because gp78/AMFR is not only an E3 Ub-ligase, but also a cell-surface prometastatic oncogene that is upregulated in various malignant cancers, our finding that hepatic gp78/AMFR knockout can enhance P450-dependent bioactivation of relevant cancer chemotherapeutic prodrugs is of therapeutic relevance and noteworthy in prospective drug design and development. SIGNIFICANCE STATEMENT: The cell-surface and ER transmembrane protein gp78/AMFR, a receptor for the prometastatic autocrine motility factor (AMF), as well as an E3 ubiquitin-ligase involved in the ER-associated degradation (ERAD) of not only the tumor metastatic suppressor KAI1 but also of hepatic cytochromes P450, is upregulated in various human cancers, enhancing their invasiveness, metastatic potential, and poor prognosis. Liver-specific gp78/AMFR genetic ablation results in functional protein stabilization of several hepatic P450s and consequently enhanced drug and prodrug metabolism, a feature that could be therapeutically exploited in the bioactivation of chemotherapeutic prodrugs through design and development of novel short-term gp78/AMFR chemical inhibitors.
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Affiliation(s)
- Doyoung Kwon
- Departments of Cellular and Molecular Pharmacology (D.K., S.-M.K., Y.L., M.A.C.), Pharmaceutical Chemistry (M.A.C.), and Bioengineering and Therapeutic Sciences (M.A.C.) and The Liver Center (M.A.C.), University of California San Francisco, San Francisco, California; and Clinical Pharmacology Program, Division of Cardiology, Department of Medicine, Center for Tobacco Control Research and Education, University of California, San Francisco, California (P.J.)
| | - Sung-Mi Kim
- Departments of Cellular and Molecular Pharmacology (D.K., S.-M.K., Y.L., M.A.C.), Pharmaceutical Chemistry (M.A.C.), and Bioengineering and Therapeutic Sciences (M.A.C.) and The Liver Center (M.A.C.), University of California San Francisco, San Francisco, California; and Clinical Pharmacology Program, Division of Cardiology, Department of Medicine, Center for Tobacco Control Research and Education, University of California, San Francisco, California (P.J.)
| | - Peyton Jacob
- Departments of Cellular and Molecular Pharmacology (D.K., S.-M.K., Y.L., M.A.C.), Pharmaceutical Chemistry (M.A.C.), and Bioengineering and Therapeutic Sciences (M.A.C.) and The Liver Center (M.A.C.), University of California San Francisco, San Francisco, California; and Clinical Pharmacology Program, Division of Cardiology, Department of Medicine, Center for Tobacco Control Research and Education, University of California, San Francisco, California (P.J.)
| | - Yi Liu
- Departments of Cellular and Molecular Pharmacology (D.K., S.-M.K., Y.L., M.A.C.), Pharmaceutical Chemistry (M.A.C.), and Bioengineering and Therapeutic Sciences (M.A.C.) and The Liver Center (M.A.C.), University of California San Francisco, San Francisco, California; and Clinical Pharmacology Program, Division of Cardiology, Department of Medicine, Center for Tobacco Control Research and Education, University of California, San Francisco, California (P.J.)
| | - Maria Almira Correia
- Departments of Cellular and Molecular Pharmacology (D.K., S.-M.K., Y.L., M.A.C.), Pharmaceutical Chemistry (M.A.C.), and Bioengineering and Therapeutic Sciences (M.A.C.) and The Liver Center (M.A.C.), University of California San Francisco, San Francisco, California; and Clinical Pharmacology Program, Division of Cardiology, Department of Medicine, Center for Tobacco Control Research and Education, University of California, San Francisco, California (P.J.)
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14
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Deol KK, Lorenz S, Strieter ER. Enzymatic Logic of Ubiquitin Chain Assembly. Front Physiol 2019; 10:835. [PMID: 31333493 PMCID: PMC6624479 DOI: 10.3389/fphys.2019.00835] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/17/2019] [Indexed: 12/12/2022] Open
Abstract
Protein ubiquitination impacts virtually every biochemical pathway in eukaryotic cells. The fate of a ubiquitinated protein is largely dictated by the type of ubiquitin modification with which it is decorated, including a large variety of polymeric chains. As a result, there have been intense efforts over the last two decades to dissect the molecular details underlying the synthesis of ubiquitin chains by ubiquitin-conjugating (E2) enzymes and ubiquitin ligases (E3s). In this review, we highlight these advances. We discuss the evidence in support of the alternative models of transferring one ubiquitin at a time to a growing substrate-linked chain (sequential addition model) versus transferring a pre-assembled ubiquitin chain (en bloc model) to a substrate. Against this backdrop, we outline emerging principles of chain assembly: multisite interactions, distinct mechanisms of chain initiation and elongation, optimal positioning of ubiquitin molecules that are ultimately conjugated to each other, and substrate-assisted catalysis. Understanding the enzymatic logic of ubiquitin chain assembly has important biomedical implications, as the misregulation of many E2s and E3s and associated perturbations in ubiquitin chain formation contribute to human disease. The resurgent interest in bifunctional small molecules targeting pathogenic proteins to specific E3s for polyubiquitination and subsequent degradation provides an additional incentive to define the mechanisms responsible for efficient and specific chain synthesis and harness them for therapeutic benefit.
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Affiliation(s)
- Kirandeep K Deol
- Department of Chemistry, University of Massachusetts, Amherst, MA, United States
| | - Sonja Lorenz
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Eric R Strieter
- Department of Chemistry, University of Massachusetts, Amherst, MA, United States.,Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, United States
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15
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Wiegering A, Rüther U, Gerhardt C. The Role of Primary Cilia in the Crosstalk between the Ubiquitin⁻Proteasome System and Autophagy. Cells 2019; 8:cells8030241. [PMID: 30875746 PMCID: PMC6468794 DOI: 10.3390/cells8030241] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 03/06/2019] [Accepted: 03/11/2019] [Indexed: 12/22/2022] Open
Abstract
Protein degradation is a pivotal process for eukaryotic development and homeostasis. The majority of proteins are degraded by the ubiquitin⁻proteasome system and by autophagy. Recent studies describe a crosstalk between these two main eukaryotic degradation systems which allows for establishing a kind of safety mechanism. If one of these degradation systems is hampered, the other compensates for this defect. The mechanism behind this crosstalk is poorly understood. Novel studies suggest that primary cilia, little cellular protrusions, are involved in the regulation of the crosstalk between the two degradation systems. In this review article, we summarise the current knowledge about the association between cilia, the ubiquitin⁻proteasome system and autophagy.
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Affiliation(s)
- Antonia Wiegering
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, 40225 Düsseldorf, Germany.
| | - Ulrich Rüther
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, 40225 Düsseldorf, Germany.
| | - Christoph Gerhardt
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, 40225 Düsseldorf, Germany.
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16
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Scott DC, Schulman BA. Dual-color pulse-chase ubiquitination assays to simultaneously monitor substrate priming and extension. Methods Enzymol 2019; 618:29-48. [PMID: 30850057 DOI: 10.1016/bs.mie.2019.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Many fundamental discoveries in ubiquitin-proteasome research have relied on reconstitution of activities from purified or recombinantly expressed components. These include landmark discoveries of E1-E2-E3 mechanisms, in which ubiquitin (UB) is initially activated and then covalently shuttled between enzyme active sites and ultimately ligated to substrate or substrate-linked UBs during polyubiquitination. However, recent studies have unearthed enormous variations on the E1-E2-E3 theme; for example, one E3 may employ two distinct E2s, or two different E3s may act in a single assembly or in series, to prime substrates directly with UB and subsequently decorate them with myriad types of polyubiquitin chains. To dissect this complexity, it can be helpful to monitor specific UB transfer reactions in isolation, rather than the end-point products formed upon mixing all enzymes in a cascade. Pulse-chase assays enable observation of a single reaction step and also allow one to differentially label UBs carried by different enzymes within the same tube. In such assays, the "pulse" reaction generates a thioester-linked enzyme~UB intermediate, while the "chase" monitors UB transfer to downstream components over time. Here, we describe pulse-chase assays for detecting fluorescent-UB in E2~UB intermediates. These assays enable direct assessment of particular ligation reactions, alone and in combination, to explore roles of multiple enzymatic cascades in the same tube. We anticipate this technique can be adapted to many different E2s, as well as thioester-forming E3s, to dissect ubiquitination by many distinct enzyme cascades.
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Affiliation(s)
- Daniel C Scott
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Brenda A Schulman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, United States; Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany.
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17
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Mashahreh B, Reiss Y, Wiener R, Ravid T. Assays for dissecting the in vitro enzymatic activity of yeast Ubc7. Methods Enzymol 2019; 619:71-95. [PMID: 30910030 DOI: 10.1016/bs.mie.2018.12.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Ubiquitin (Ub)-mediated protein degradation is a key cellular defense mechanism that detects and eliminates defective proteins. A major intracellular site of protein quality control degradation is the endoplasmic reticulum (ER), hence the term ER-associated degradation, or endoplasmic reticulum-associated degradation (ERAD). Yeast ERAD is composed of three Ub-protein conjugation complexes, named according to their E3 Ub-protein ligase components, Hrd1, Doa10, and the Asi complex, which resides at the nuclear envelope (NE). These ER/NE membrane-associated RING-type E3 ligases recognize and ubiquitylate defective proteins in cooperation with the E2 conjugating enzyme Ubc7 and the obligatory Ubc7 cofactor Cue1. Interaction of Ubc7 with the RING domains of its cognate E3 Ub-protein ligases stimulates the formation of isopeptide (amide) Ub-Ub linkages. Each isopeptide bond is formed by transfer of an Ubc7-linked activated Ub to a lysine side chain of an acceptor Ub. Multiple Ub transfer reactions form a poly-Ub chain that targets the conjugated protein for degradation by the proteasome. To study the mechanism of Ub-Ub bond formation, this reaction is reconstituted in a cell-free system consisting of recombinant E1, Ub, Ubc7, its cofactor Cue1, and the RING domain of either Doa10 or Hrd1. Here we provide detailed protocols for the purification of the required recombinant proteins and for the reactions that produce an Ub-Ub bond, specifically, the formation of an Ubc7~Ub thiolester (Ub charging) and subsequent formation of the isopeptide Ub-Ub linkage (Ub transfer). These protocols also provide a useful guideline for similar in vitro ubiquitylation reactions intended to explore the mechanism of other Ub-conjugation systems.
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Affiliation(s)
- Bayan Mashahreh
- Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yuval Reiss
- Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Reuven Wiener
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (IMRIC), Hebrew University School of Medicine, Jerusalem, Israel
| | - Tommer Ravid
- Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
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18
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de Oliveira JF, do Prado PFV, da Costa SS, Sforça ML, Canateli C, Ranzani AT, Maschietto M, de Oliveira PSL, Otto PA, Klevit RE, Krepischi ACV, Rosenberg C, Franchini KG. Mechanistic insights revealed by a UBE2A mutation linked to intellectual disability. Nat Chem Biol 2018; 15:62-70. [PMID: 30531907 DOI: 10.1038/s41589-018-0177-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 10/26/2018] [Indexed: 12/30/2022]
Abstract
Ubiquitin-conjugating enzymes (E2) enable protein ubiquitination by conjugating ubiquitin to their catalytic cysteine for subsequent transfer to a target lysine side chain. Deprotonation of the incoming lysine enables its nucleophilicity, but determinants of lysine activation remain poorly understood. We report a novel pathogenic mutation in the E2 UBE2A, identified in two brothers with mild intellectual disability. The pathogenic Q93E mutation yields UBE2A with impaired aminolysis activity but no loss of the ability to be conjugated with ubiquitin. Importantly, the low intrinsic reactivity of UBE2A Q93E was not overcome by a cognate ubiquitin E3 ligase, RAD18, with the UBE2A target PCNA. However, UBE2A Q93E was reactive at high pH or with a low-pKa amine as the nucleophile, thus providing the first evidence of reversion of a defective UBE2A mutation. We propose that Q93E substitution perturbs the UBE2A catalytic microenvironment essential for lysine deprotonation during ubiquitin transfer, thus generating an enzyme that is disabled but not dead.
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Affiliation(s)
| | | | - Silvia Souza da Costa
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Mauricio Luis Sforça
- Brazilian Biosciences National Laboratory, Center for Research in Energy and Materials, Campinas, Brazil
| | - Camila Canateli
- Brazilian Biosciences National Laboratory, Center for Research in Energy and Materials, Campinas, Brazil
| | - Americo Tavares Ranzani
- Brazilian Biosciences National Laboratory, Center for Research in Energy and Materials, Campinas, Brazil
| | - Mariana Maschietto
- Brazilian Biosciences National Laboratory, Center for Research in Energy and Materials, Campinas, Brazil
| | | | - Paulo A Otto
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Rachel E Klevit
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | | | - Carla Rosenberg
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Kleber Gomes Franchini
- Brazilian Biosciences National Laboratory, Center for Research in Energy and Materials, Campinas, Brazil. .,Department of Internal Medicine, School of Medicine, University of Campinas, Campinas, Brazil.
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19
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Mehrtash AB, Hochstrasser M. Ubiquitin-dependent protein degradation at the endoplasmic reticulum and nuclear envelope. Semin Cell Dev Biol 2018; 93:111-124. [PMID: 30278225 DOI: 10.1016/j.semcdb.2018.09.013] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/26/2018] [Accepted: 09/27/2018] [Indexed: 01/01/2023]
Abstract
Numerous nascent proteins undergo folding and maturation within the luminal and membrane compartments of the endoplasmic reticulum (ER). Despite the presence of various factors in the ER that promote protein folding, many proteins fail to properly fold and assemble and are subsequently degraded. Regulatory proteins in the ER also undergo degradation in a way that is responsive to stimuli or the changing needs of the cell. As in most cellular compartments, the ubiquitin-proteasome system (UPS) is responsible for the majority of the degradation at the ER-in a process termed ER-associated degradation (ERAD). Autophagic processes utilizing ubiquitin-like protein-conjugating systems also play roles in protein degradation at the ER. The ER is continuous with the nuclear envelope (NE), which consists of the outer nuclear membrane (ONM) and inner nuclear membrane (INM). While ERAD is known also to occur at the NE, only some of the ERAD ubiquitin-ligation pathways function at the INM. Protein degradation machineries in the ER/NE target a wide variety of substrates in multiple cellular compartments, including the cytoplasm, nucleoplasm, ER lumen, ER membrane, and the NE. Here, we review the protein degradation machineries of the ER and NE and the underlying mechanisms dictating recognition and processing of substrates by these machineries.
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Affiliation(s)
- Adrian B Mehrtash
- Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, 06520, CT, USA.
| | - Mark Hochstrasser
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, 06520, USA; Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, 06520, CT, USA.
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20
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Lu G, Weng S, Matyskiela M, Zheng X, Fang W, Wood S, Surka C, Mizukoshi R, Lu CC, Mendy D, Jang IS, Wang K, Marella M, Couto S, Cathers B, Carmichael J, Chamberlain P, Rolfe M. UBE2G1 governs the destruction of cereblon neomorphic substrates. eLife 2018; 7:40958. [PMID: 30234487 PMCID: PMC6185104 DOI: 10.7554/elife.40958] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/19/2018] [Indexed: 12/11/2022] Open
Abstract
The cereblon modulating agents (CMs) including lenalidomide, pomalidomide and CC-220 repurpose the Cul4-RBX1-DDB1-CRBN (CRL4CRBN) E3 ubiquitin ligase complex to induce the degradation of specific neomorphic substrates via polyubiquitination in conjunction with E2 ubiquitin-conjugating enzymes, which have until now remained elusive. Here we show that the ubiquitin-conjugating enzymes UBE2G1 and UBE2D3 cooperatively promote the K48-linked polyubiquitination of CRL4CRBN neomorphic substrates via a sequential ubiquitination mechanism. Blockade of UBE2G1 diminishes the ubiquitination and degradation of neomorphic substrates, and consequent antitumor activities elicited by all tested CMs. For example, UBE2G1 inactivation significantly attenuated the degradation of myeloma survival factors IKZF1 and IKZF3 induced by lenalidomide and pomalidomide, hence conferring drug resistance. UBE2G1-deficient myeloma cells, however, remained sensitive to a more potent IKZF1/3 degrader CC-220. Collectively, it will be of fundamental interest to explore if loss of UBE2G1 activity is linked to clinical resistance to drugs that hijack the CRL4CRBN to eliminate disease-driving proteins.
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Affiliation(s)
- Gang Lu
- Celgene Corporation, San Diego, United States
| | | | | | - Xinde Zheng
- Celgene Corporation, San Diego, United States
| | - Wei Fang
- Celgene Corporation, San Diego, United States
| | - Scott Wood
- Celgene Corporation, San Diego, United States
| | | | | | | | - Derek Mendy
- Celgene Corporation, San Diego, United States
| | | | - Kai Wang
- Celgene Corporation, San Diego, United States
| | | | | | | | | | | | - Mark Rolfe
- Celgene Corporation, San Diego, United States
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21
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Blount JR, Libohova K, Marsh GB, Sutton JR, Todi SV. Expression and Regulation of Deubiquitinase-Resistant, Unanchored Ubiquitin Chains in Drosophila. Sci Rep 2018; 8:8513. [PMID: 29855490 PMCID: PMC5981470 DOI: 10.1038/s41598-018-26364-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/10/2018] [Indexed: 01/03/2023] Open
Abstract
The modifier protein, ubiquitin (Ub) regulates various cellular pathways by controlling the fate of substrates to which it is conjugated. Ub moieties are also conjugated to each other, forming chains of various topologies. In cells, poly-Ub is attached to proteins and also exists in unanchored form. Accumulation of unanchored poly-Ub is thought to be harmful and quickly dispersed through dismantling by deubiquitinases (DUBs). We wondered whether disassembly by DUBs is necessary to control unanchored Ub chains in vivo. We generated Drosophila melanogaster lines that express Ub chains non-cleavable into mono-Ub by DUBs. These chains are rapidly modified with different linkages and represent various types of unanchored species. We found that unanchored poly-Ub is not devastating in Drosophila, under normal conditions or during stress. The DUB-resistant, free Ub chains are degraded by the proteasome, at least in part through the assistance of VCP and its cofactor, p47. Also, unanchored poly-Ub that cannot be cleaved by DUBs can be conjugated en bloc, in vivo. Our results indicate that unanchored poly-Ub species need not be intrinsically toxic; they can be controlled independently of DUB-based disassembly by being degraded, or through conjugation onto other proteins.
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Affiliation(s)
- Jessica R Blount
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Kozeta Libohova
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Gregory B Marsh
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Joanna R Sutton
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Sokol V Todi
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA. .,Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.
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22
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Freitas FB, Frouco G, Martins C, Ferreira F. African swine fever virus encodes for an E2-ubiquitin conjugating enzyme that is mono- and di-ubiquitinated and required for viral replication cycle. Sci Rep 2018; 8:3471. [PMID: 29472632 PMCID: PMC5823848 DOI: 10.1038/s41598-018-21872-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/12/2018] [Indexed: 12/21/2022] Open
Abstract
African swine fever virus is the etiological agent of a contagious and fatal acute haemorrhagic viral disease for which there are no vaccines or therapeutic options. The ASFV encodes for a putative E2 ubiquitin conjugating enzyme (ORF I215L) that shows sequence homology with eukaryotic counterparts. In the present study, we showed that pI215L acts as an E2-ubiquitin like enzyme in a large range of pH values and temperatures, after short incubation times. Further experiments revealed that pI215L is polyubiquitinated instead of multi-mono-ubiquitinated and Cys85 residue plays an essential role in the transthioesterification reaction. In infected cells, I215L gene is transcribed from 2 hours post infection and immunoblot analysis confirmed that pI215L is expressed from 4 hpi. Immunofluorescence studies revealed that pI215L is recruited to viral factories from 8 hpi and a diffuse distribution pattern throughout the nucleus and cytoplasm. siRNA studies suggested that pI215L plays a critical role in the transcription of late viral genes and viral DNA replication. Altogether, our results emphasize the potential use of this enzyme as target for drug and vaccine development against ASF.
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Affiliation(s)
- Ferdinando B Freitas
- Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, 1300-477, Portugal
| | - Gonçalo Frouco
- Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, 1300-477, Portugal
| | - Carlos Martins
- Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, 1300-477, Portugal
| | - Fernando Ferreira
- Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, 1300-477, Portugal.
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23
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Grossegesse M, Doellinger J, Fritsch A, Laue M, Piesker J, Schaade L, Nitsche A. Global ubiquitination analysis reveals extensive modification and proteasomal degradation of cowpox virus proteins, but preservation of viral cores. Sci Rep 2018; 8:1807. [PMID: 29379051 PMCID: PMC5788924 DOI: 10.1038/s41598-018-20130-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 01/15/2018] [Indexed: 11/09/2022] Open
Abstract
The emergence of Variola virus-like viruses by natural evolution of zoonotic Orthopoxviruses, like Cowpox virus (CPXV), is a global health threat. The proteasome is essential for poxvirus replication, making the viral components interacting with the ubiquitin-proteasome system attractive antiviral targets. We show that proteasome inhibition impairs CPXV replication by prevention of uncoating, suggesting that uncoating is mediated by proteasomal degradation of viral core proteins. Although Orthopoxvirus particles contain considerable amounts of ubiquitin, distinct modification sites are largely unknown. Therefore, for the first time, we analyzed globally ubiquitination sites in CPXV mature virion proteins using LC-MS/MS. Identification of 137 conserved sites in 54 viral proteins among five CPXV strains revealed extensive ubiquitination of structural core proteins. Moreover, since virions contained primarily K48-linked polyubiquitin, we hypothesized that core proteins are modified accordingly. However, quantitative analysis of ubiquitinated CPXV proteins early in infection showed no proteasomal degradation of core proteins. Instead, our data indicate that the recently suggested proteasomal regulation of the uncoating factor E5 is a prerequisite for uncoating. Expanding our understanding of poxvirus uncoating and elucidating a multitude of novel ubiquitination sites in poxvirus proteins, the present study verifies the major biological significance of ubiquitin in poxvirus infection.
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Affiliation(s)
- Marica Grossegesse
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens: Highly Pathogenic Viruses (ZBS 1), Berlin, 13353, Germany
| | - Joerg Doellinger
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens: Highly Pathogenic Viruses (ZBS 1), Berlin, 13353, Germany. .,Robert Koch Institute, Centre for Biological Threats and Special Pathogens: Proteomics and Spectroscopy (ZBS 6), Berlin, 13353, Germany.
| | - Annemarie Fritsch
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens: Highly Pathogenic Viruses (ZBS 1), Berlin, 13353, Germany
| | - Michael Laue
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens: Advanced Light and Electron Microscopy (ZBS 4), Berlin, 13353, Germany
| | - Janett Piesker
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens: Advanced Light and Electron Microscopy (ZBS 4), Berlin, 13353, Germany
| | - Lars Schaade
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens, Berlin, 13353, Germany
| | - Andreas Nitsche
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens: Highly Pathogenic Viruses (ZBS 1), Berlin, 13353, Germany
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24
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Shim SM, Choi HR, Sung KW, Lee YJ, Kim ST, Kim D, Mun SR, Hwang J, Cha-Molstad H, Ciechanover A, Kim BY, Kwon YT. The endoplasmic reticulum-residing chaperone BiP is short-lived and metabolized through N-terminal arginylation. Sci Signal 2018; 11:11/511/eaan0630. [PMID: 29295953 DOI: 10.1126/scisignal.aan0630] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BiP and other endoplasmic reticulum (ER)-resident proteins are thought to be metabolically stable and to function primarily in the ER lumen. We sought to assess how the abundance of these proteins dynamically fluctuates in response to various stresses and how their subpopulations are relocated to non-ER compartments such as the cytosol. We showed that the molecular chaperone BiP (also known as GRP78) was short-lived under basal conditions and ER stress. The turnover of BiP was in part driven by its amino-terminal arginylation (Nt-arginylation) by the arginyltransferase ATE1, which generated an autophagic N-degron of the N-end rule pathway. ER stress elicited the formation of R-BiP, an effect that was increased when the proteasome was also inhibited. Nt-arginylation correlated with the cytosolic relocalization of BiP under the types of stress tested. The cytosolic relocalization of BiP did not require the functionality of the unfolded protein response or the Sec61- or Derlin1-containing translocon. A key inhibitor of the turnover and Nt-arginylation of BiP was HERP (homocysteine-responsive ER protein), a 43-kDa ER membrane-integrated protein that is an essential component of ER-associated protein degradation. Pharmacological inhibition of the ER-Golgi secretory pathway also suppressed R-BiP formation. Finally, we showed that cytosolic R-BiP induced by ER stress and proteasomal inhibition was routed to autophagic vacuoles and possibly additional metabolic fates. These results suggest that Nt-arginylation is a posttranslational modification that modulates the function, localization, and metabolic fate of ER-resident proteins.
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Affiliation(s)
- Sang Mi Shim
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
| | - Ha Rim Choi
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
| | - Ki Woon Sung
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
| | - Yoon Jee Lee
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
| | - Sung Tae Kim
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Center for Pharmacogenetics and Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Daeho Kim
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Department of Biophysics and Chemical Biology, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Su Ran Mun
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
| | - Joonsung Hwang
- World Class Institute, Korea Research Institute of Bioscience and Biotechnology, Ochang, Cheongwon 28116, Republic of Korea
| | - Hyunjoo Cha-Molstad
- World Class Institute, Korea Research Institute of Bioscience and Biotechnology, Ochang, Cheongwon 28116, Republic of Korea
| | - Aaron Ciechanover
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Tumor and Vascular Biology Research Center, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Bo Yeon Kim
- World Class Institute, Korea Research Institute of Bioscience and Biotechnology, Ochang, Cheongwon 28116, Republic of Korea.
| | - Yong Tae Kwon
- Protein Metabolism Medical Research Center, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea. .,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea.,Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
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25
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Central catalytic domain of BRAP (RNF52) recognizes the types of ubiquitin chains and utilizes oligo-ubiquitin for ubiquitylation. Biochem J 2017; 474:3207-3226. [PMID: 28768733 PMCID: PMC5628404 DOI: 10.1042/bcj20161104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 07/31/2017] [Accepted: 08/02/2017] [Indexed: 12/02/2022]
Abstract
Really interesting new gene (RING)-finger protein 52 (RNF52), an E3 ubiquitin ligase, is found in eukaryotes from yeast to humans. Human RNF52 is known as breast cancer type 1 susceptibility protein (BRCA1)-associated protein 2 (BRAP or BRAP2). The central catalytic domain of BRAP comprises four subdomains: nucleotide-binding α/β plait (NBP), really interesting new gene (RING) zinc finger, ubiquitin-specific protease (UBP)-like zinc finger (ZfUBP), and coiled-coil (CC). This domain architecture is conserved in RNF52 orthologs; however, the domain's function in the ubiquitin system has not been delineated. In the present study, we discovered that the RNF52 domain, comprising NBP–RING–ZfUBP–CC, binds to ubiquitin chains (oligo-ubiquitin) but not to the ubiquitin monomers, and can utilize various ubiquitin chains for ubiquitylation and auto-ubiquitylation. The RNF52 domain preferentially bound to M1- and K63-linked di-ubiquitin chains, weakly to K27-linked chains, but not to K6-, K11-, or K48-linked chains. The binding preferences of the RNF52 domain for ubiquitin-linkage types corresponded to ubiquitin usage in the ubiquitylation reaction, except for K11-, K29-, and K33-linked chains. Additionally, the RNF52 domain directly ligated the intact M1-linked, tri-, and tetra-ubiquitin chains and recognized the structural alterations caused by the phosphomimetic mutation of these ubiquitin chains. Full-length BRAP had nearly the same specificity for the ubiquitin-chain types as the RNF52 domain alone. Mass spectrometry analysis of oligomeric ubiquitylation products, mediated by the RNF52 domain, revealed that the ubiquitin-linkage types and auto-ubiquitylation sites depend on the length of ubiquitin chains. Here, we propose a model for the oligomeric ubiquitylation process, controlled by the RNF52 domain, which is not a sequential assembly process involving monomers.
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26
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Magala P, Bocik WE, Majumdar A, Tolman JR. Conformational Dynamics Modulate Activation of the Ubiquitin Conjugating Enzyme Ube2g2. ACS OMEGA 2017; 2:4581-4592. [PMID: 28884161 PMCID: PMC5579538 DOI: 10.1021/acsomega.7b00205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 07/18/2017] [Indexed: 06/07/2023]
Abstract
The ubiquitin conjugating enzyme Ube2g2 together with its cognate E3 ligase gp78 catalyzes the synthesis of lysine-48 polyubiquitin chains constituting signals for the proteasomal degradation of misfolded proteins in the endoplasmic reticulum. Here, we employ NMR spectroscopy in combination with single-turnover diubiquitin formation assays to examine the role of the RING domain from gp78 in the catalytic activation of Ube2g2∼Ub conjugates. We find that approximately 60% of the Ube2g2∼Ub conjugates occupy a closed conformation in the absence of gp78-RING, with the population increasing to 82% upon gp78-RING binding. As expected, strong mutations in the hydrophobic patch residues of the ∼Ub moiety result in Ube2g2∼Ub populating only open states with corresponding loss of the ubiquitin conjugation activity. Less disruptive mutations introduced into the hydrophobic patch of the ∼Ub moiety also destabilize the closed conformational state, yet the corresponding effect on the ubiquitin conjugation activity ranges from complete loss to an enhancement of the catalytic activity. These results present a picture in which Ube2g2's active site is in a state of continual dynamic flux with the organization of the active site into a catalytically viable conformation constituting the rate-limiting step for a single ubiquitin ligation event. Ube2g2's function as a highly specific K48-polyubiquitin chain elongator leads us to speculate that this may be a strategy by which Ube2g2 reduces the probability of nonproductive catalytic outcomes in the absence of available substrate.
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27
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Bacterial effector NleL promotes enterohemorrhagic E. coli-induced attaching and effacing lesions by ubiquitylating and inactivating JNK. PLoS Pathog 2017; 13:e1006534. [PMID: 28753655 PMCID: PMC5549993 DOI: 10.1371/journal.ppat.1006534] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 08/09/2017] [Accepted: 07/15/2017] [Indexed: 11/25/2022] Open
Abstract
As a major diarrheagenic human pathogen, enterohemorrhagic Escherichia coli (EHEC) produce attaching and effacing (A/E) lesions, characterized by the formation of actin pedestals, on mammalian cells. A bacterial T3SS effector NleL from EHEC O157:H7 was recently shown to be a HECT-like E3 ligase in vitro, but its biological functions and host targets remain elusive. Here, we report that NleL is required to effectively promote EHEC-induced A/E lesions and bacterial infection. Furthermore, human c-Jun NH2-terminal kinases (JNKs) were identified as primary substrates of NleL. NleL-induced JNK ubiquitylation, particularly mono-ubiquitylation at the Lys 68 residue of JNK, impairs JNK’s interaction with an upstream kinase MKK7, thus disrupting JNK phosphorylation and activation. This subsequently suppresses the transcriptional activity of activator protein-1 (AP-1), which modulates the formation of the EHEC-induced actin pedestals. Moreover, JNK knockdown or inhibition in host cells complements NleL deficiency in EHEC infection. Thus, we demonstrate that the effector protein NleL enhances the ability of EHEC to infect host cells by targeting host JNK, and elucidate an inhibitory role of ubiquitylation in regulating JNK phosphorylation. Enterohemorrhagic Escherichia coli (EHEC) can cause attaching and effacing (A/E) lesions to form in the colons of animals and humans, contributing to severe bacterial infection. NleL, an E3 ubiquitin ligase from EHEC O157:H7 is one of the bacterial type III secretion effectors that may be involved in the regulation of A/E lesions. However, NleL’s exact host targets and the detailed mechanistic actions are still unclear. Here, we report that the effector protein NleL effectively promotes EHEC-induced A/E lesions and bacterial infection by targeting the host JNK protein. Specifically, we find that NleL-mediated JNK ubiquitylation abolishes phosphorylation and activation of host JNK, subsequently suppressing the host JNK/AP-1 signaling pathway to favor the formation of EHEC-mediated actin pedestals on the surface of mammalian cells. Collectively, our work has not only discovered the A/E lesion-promoting function of NleL during EHEC infection, but also revealed a novel regulatory mechanism of host JNK protein.
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28
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Mechanism and disease association of E2-conjugating enzymes: lessons from UBE2T and UBE2L3. Biochem J 2017; 473:3401-3419. [PMID: 27729585 PMCID: PMC5095918 DOI: 10.1042/bcj20160028] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 08/09/2016] [Indexed: 02/07/2023]
Abstract
Ubiquitin signalling is a fundamental eukaryotic regulatory system, controlling diverse cellular functions. A cascade of E1, E2, and E3 enzymes is required for assembly of distinct signals, whereas an array of deubiquitinases and ubiquitin-binding modules edit, remove, and translate the signals. In the centre of this cascade sits the E2-conjugating enzyme, relaying activated ubiquitin from the E1 activating enzyme to the substrate, usually via an E3 ubiquitin ligase. Many disease states are associated with dysfunction of ubiquitin signalling, with the E3s being a particular focus. However, recent evidence demonstrates that mutations or impairment of the E2s can lead to severe disease states, including chromosome instability syndromes, cancer predisposition, and immunological disorders. Given their relevance to diseases, E2s may represent an important class of therapeutic targets. In the present study, we review the current understanding of the mechanism of this important family of enzymes, and the role of selected E2s in disease.
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29
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Chakraborty J, Basso V, Ziviani E. Post translational modification of Parkin. Biol Direct 2017; 12:6. [PMID: 28222786 PMCID: PMC5319146 DOI: 10.1186/s13062-017-0176-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/06/2017] [Indexed: 11/10/2022] Open
Abstract
Mutations in the gene encoding for the E3 ubiquitin ligase Parkin are associated to a rare form of familiar autosomal recessive Parkinsonism. Despite decades of research on the Parkin protein, whose structure has been recently solved, little is known about the specific signalling pathways that lead to Parkin activation. Parkin activity spans from mitochondria quality control to tumor suppression and stress protection; it is thus tempting to hypothesize that the broad impact of Parkin on cellular physiology might be the result of different post translational modifications that can be controlled by balanced opposing events. Sequence alignment of Parkin from different species indicates high homology between domains across Parkin orthologs and identifies highly conserved amino acid residues that, if modified, impinge on Parkin functions. In this review, we summarize findings on post translational modifications that have been shown to affect Parkin activity and stability. REVIEWERS This article was reviewed by Prof. Dr. Konstanze F. Winklhofer and by Prof. Thomas Simmen. Both reviewers have been nominated by Professor Luca Pellegrini.
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Affiliation(s)
- Joy Chakraborty
- Department of Biology, University of Padova, Via Ugo Bassi 58b, 35131, Padova, Italy
| | - Valentina Basso
- Department of Biology, University of Padova, Via Ugo Bassi 58b, 35131, Padova, Italy
| | - Elena Ziviani
- Department of Biology, University of Padova, Via Ugo Bassi 58b, 35131, Padova, Italy. .,Istituto IRCCS San Camillo, Lido di Venezia, Venezia,, Italy.
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30
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Liu C, Liu W, Ye Y, Li W. Ufd2p synthesizes branched ubiquitin chains to promote the degradation of substrates modified with atypical chains. Nat Commun 2017; 8:14274. [PMID: 28165462 PMCID: PMC5303827 DOI: 10.1038/ncomms14274] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 12/14/2016] [Indexed: 12/17/2022] Open
Abstract
Ubiquitination of a subset of proteins by ubiquitin chain elongation factors (E4), represented by Ufd2p in Saccharomyces cerevisiae, is a pivotal regulator for many biological processes. However, the mechanism of Ufd2p-mediated ubiquitination is largely unclear. Here, we show that Ufd2p catalyses K48-linked multi-monoubiquitination on K29-linked ubiquitin chains assembled by the ubiquitin ligase (Ufd4p), resulting in branched ubiquitin chains. This reaction depends on the interaction of K29-linked ubiquitin chains with two N-terminal loops of Ufd2p. Only following the addition of K48-linked ubiquitin to substrates modified with K29-linked ubiquitin chains, can the substrates be escorted to the proteasome for degradation. We demonstrate that this ubiquitin chain linkage switching reaction is essential for ERAD, oleic acid and acid pH resistance in yeast. Thus, our results suggest that Ufd2p functions by switching ubiquitin chain linkages to allow the degradation of proteins modified with a ubiquitin linkage, which is normally not targeted to the proteasome. How ubiquitination affects the proteins it modifies varies according to the type of linkage between ubiquitin moieties. Here, Liu et al. show how yeast Udf2p promotes K48 linkage formation onto K29-linked chains to generate branched K29-K48 ubiquitin chains that target its substrate to the proteasome.
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Affiliation(s)
- Chao Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weixiao Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yihong Ye
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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31
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Lv Z, Rickman KA, Yuan L, Williams K, Selvam SP, Woosley AN, Howe PH, Ogretmen B, Smogorzewska A, Olsen SK. S. pombe Uba1-Ubc15 Structure Reveals a Novel Regulatory Mechanism of Ubiquitin E2 Activity. Mol Cell 2017; 65:699-714.e6. [PMID: 28162934 DOI: 10.1016/j.molcel.2017.01.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 11/28/2016] [Accepted: 01/04/2017] [Indexed: 12/12/2022]
Abstract
Ubiquitin (Ub) E1 initiates the Ub conjugation cascade by activating and transferring Ub to tens of different E2s. How Ub E1 cooperates with E2s that differ substantially in their predicted E1-interacting residues is unknown. Here, we report the structure of S. pombe Uba1 in complex with Ubc15, a Ub E2 with intrinsically low E1-E2 Ub thioester transfer activity. The structure reveals a distinct Ubc15 binding mode that substantially alters the network of interactions at the E1-E2 interface compared to the only other available Ub E1-E2 structure. Structure-function analysis reveals that the intrinsically low activity of Ubc15 largely results from the presence of an acidic residue at its N-terminal region. Notably, Ub E2 N termini are serine/threonine rich in many other Ub E2s, leading us to hypothesize that phosphorylation of these sites may serve as a novel negative regulatory mechanism of Ub E2 activity, which we demonstrate biochemically and in cell-based assays.
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Affiliation(s)
- Zongyang Lv
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Kimberly A Rickman
- Laboratory of Genome Maintenance, Rockefeller University, New York, NY 10065, USA
| | - Lingmin Yuan
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Katelyn Williams
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Shanmugam Panneer Selvam
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Alec N Woosley
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Philip H Howe
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Besim Ogretmen
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, Rockefeller University, New York, NY 10065, USA
| | - Shaun K Olsen
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA.
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32
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Zhao Y, Zhang T, Huo H, Ye Y, Liu Y. Lunapark Is a Component of a Ubiquitin Ligase Complex Localized to the Endoplasmic Reticulum Three-way Junctions. J Biol Chem 2016; 291:18252-62. [PMID: 27387505 DOI: 10.1074/jbc.m116.737783] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Indexed: 11/06/2022] Open
Abstract
The endoplasmic reticulum (ER) network comprises sheets and tubules that are connected by dynamic three-way junctions. Lunapark (Lnp) localizes to and stabilizes ER three-way junctions by antagonizing the small GTPase Atlastin, but how Lnp shapes the ER network is unclear. Here, we used an affinity purification approach and mass spectrometry to identify Lnp as an interacting partner of the ER protein quality control ubiquitin ligase gp78. Accordingly, Lnp purified from mammalian cells has a ubiquitin ligase activity in vitro Intriguingly, biochemical analyses show that this activity can be attributed not only to associated ubiquitin ligase, but also to an intrinsic ubiquitin ligase activity borne by Lnp itself. This activity is contained in the N-terminal 45 amino acids of Lnp although this segment does not share homology to any known ubiquitin ligase motifs. Despite its interaction with gp78, Lnp does not seem to have a broad function in degradation of misfolded ER proteins. On the other hand, the N-terminal ubiquitin ligase-bearing motif is required for the ER three-way junction localization of Lnp. Our study identifies a new type of ubiquitin ligase and reveals a potential link between ubiquitin and ER morphology regulation.
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Affiliation(s)
- Yupeng Zhao
- From the School of Life Science and Technology, ShanghaiTech University, 100 Haike Rd., Shanghai 201210, China and
| | - Ting Zhang
- the Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Huanhuan Huo
- From the School of Life Science and Technology, ShanghaiTech University, 100 Haike Rd., Shanghai 201210, China and
| | - Yihong Ye
- the Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Yanfen Liu
- From the School of Life Science and Technology, ShanghaiTech University, 100 Haike Rd., Shanghai 201210, China and
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33
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Kim SM, Wang Y, Nabavi N, Liu Y, Correia MA. Hepatic cytochromes P450: structural degrons and barcodes, posttranslational modifications and cellular adapters in the ERAD-endgame. Drug Metab Rev 2016; 48:405-33. [PMID: 27320797 DOI: 10.1080/03602532.2016.1195403] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The endoplasmic reticulum (ER)-anchored hepatic cytochromes P450 (P450s) are enzymes that metabolize endo- and xenobiotics i.e. drugs, carcinogens, toxins, natural and chemical products. These agents modulate liver P450 content through increased synthesis or reduction via inactivation and/or proteolytic degradation, resulting in clinically significant drug-drug interactions. P450 proteolytic degradation occurs via ER-associated degradation (ERAD) involving either of two distinct routes: Ubiquitin (Ub)-dependent 26S proteasomal degradation (ERAD/UPD) or autophagic lysosomal degradation (ERAD/ALD). CYP3A4, the major human liver/intestinal P450, and the fast-turnover CYP2E1 species are degraded via ERAD/UPD entailing multisite protein phosphorylation and subsequent ubiquitination by gp78 and CHIP E3 Ub-ligases. We are gaining insight into the nature of the structural determinants involved in CYP3A4 and CYP2E1 molecular recognition in ERAD/UPD [i.e. K48-linked polyUb chains and linear and/or "conformational" phosphodegrons consisting either of consecutive sequences on surface loops and/or disordered regions, or structurally-assembled surface clusters of negatively charged acidic (Asp/Glu) and phosphorylated (Ser/Thr) residues, within or vicinal to which, Lys-residues are targeted for ubiquitination]. Structural inspection of select human liver P450s reveals that such linear or conformational phosphodegrons may indeed be a common P450-ERAD/UPD feature. By contrast, although many P450s such as the slow-turnover CYP2E1 species and rat liver CYP2B1 and CYP2C11 are degraded via ERAD/ALD, little is known about the mechanism of their ALD-targeting. On the basis of our current knowledge of ALD-substrate targeting, we propose a tripartite conjunction of K63-linked Ub-chains, P450 structural "LIR" motifs and selective cellular "cargo receptors" as plausible P450-ALD determinants.
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Affiliation(s)
- Sung-Mi Kim
- a Department of Cellular & Molecular Pharmacology , University of California San Francisco , San Francisco , CA , USA
| | - YongQiang Wang
- a Department of Cellular & Molecular Pharmacology , University of California San Francisco , San Francisco , CA , USA
| | - Noushin Nabavi
- a Department of Cellular & Molecular Pharmacology , University of California San Francisco , San Francisco , CA , USA
| | - Yi Liu
- a Department of Cellular & Molecular Pharmacology , University of California San Francisco , San Francisco , CA , USA
| | - Maria Almira Correia
- a Department of Cellular & Molecular Pharmacology , University of California San Francisco , San Francisco , CA , USA ;,b Department of Pharmaceutical Chemistry , University of California San Francisco , San Francisco , CA , USA ;,c Department of Bioengineering and Therapeutic Sciences , University of California San Francisco , San Francisco , CA , USA ;,d The Liver Center, University of California San Francisco , San Francisco , CA , USA
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34
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Heckmann BL, Zhang X, Saarinen AM, Liu J. Regulation of G0/G1 Switch Gene 2 (G0S2) Protein Ubiquitination and Stability by Triglyceride Accumulation and ATGL Interaction. PLoS One 2016; 11:e0156742. [PMID: 27248498 PMCID: PMC4889065 DOI: 10.1371/journal.pone.0156742] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 05/18/2016] [Indexed: 12/31/2022] Open
Abstract
Intracellular triglyceride (TG) hydrolysis or lipolysis is catalyzed by the key intracellular triglyceride hydrolase, adipose triglyceride lipase (ATGL). The G0/G1 Switch Gene 2 (G0S2) was recently identified as the major selective inhibitor of ATGL and its hydrolase function. Since G0S2 levels are dynamically linked and rapidly responsive to nutrient status or metabolic requirements, the identification of its regulation at the protein level is of significant value. Earlier evidence from our laboratory demonstrated that G0S2 is a short-lived protein degraded through the proteasomal pathway. However, little is currently known regarding the underlying mechanisms. In the current study we find that 1) protein degradation is initiated by K48-linked polyubiquitination of the lysine- 25 in G0S2; and 2) G0S2 protein is stabilized in response to ATGL expression and TG accumulation. Mutation of lysine-25 of G0S2 abolished ubiquitination and increased protein stability. More importantly, G0S2 was stabilized via different mechanisms in the presence of ATGL vs. in response to fatty acid (FA)-induced TG accumulation. Furthermore, G0S2 protein but not mRNA levels were reduced in the adipose tissue of ATGL-deficient mice, corroborating the involvement of ATGL in the stabilization of G0S2. Taken together our data illustrate for the first time a crucial multifaceted mechanism for the stabilization of G0S2 at the protein level.
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Affiliation(s)
- Bradlee L. Heckmann
- Department of Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Scottsdale, Arizona, United States of America
- Metabolic HEALth Program, Mayo Clinic, Scottsdale, Arizona, United States of America
- Mayo Graduate School, Rochester, Minnesota, United States of America
| | - Xiaodong Zhang
- Department of Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Scottsdale, Arizona, United States of America
- Metabolic HEALth Program, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Alicia M. Saarinen
- Department of Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Scottsdale, Arizona, United States of America
- Metabolic HEALth Program, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Jun Liu
- Department of Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Scottsdale, Arizona, United States of America
- Metabolic HEALth Program, Mayo Clinic, Scottsdale, Arizona, United States of America
- * E-mail:
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Coon TA, McKelvey AC, Lear T, Rajbhandari S, Dunn SR, Connelly W, Zhao JY, Han S, Liu Y, Weathington NM, McVerry BJ, Zhang Y, Chen BB. The proinflammatory role of HECTD2 in innate immunity and experimental lung injury. Sci Transl Med 2016; 7:295ra109. [PMID: 26157031 DOI: 10.1126/scitranslmed.aab3881] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Invading pathogens may trigger overactivation of the innate immune system, which results in the release of large amounts of proinflammatory cytokines (cytokine storm) and leads to the development of pulmonary edema, multiorgan failure, and shock. PIAS1 is a multifunctional and potent anti-inflammatory protein that negatively regulates several key inflammatory pathways such as Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and nuclear factor κB (NF-κB). We discovered a ubiquitin E3 ligase, HECTD2, which ubiquitinated and mediated the degradation of PIAS1, thus increasing inflammation in an experimental pneumonia model. We found that GSK3β phosphorylation of PIAS1 provided a phosphodegron for HECTD2 targeting. We also identified a mislocalized HECTD2 polymorphism, HECTD2(A19P), that was present in 8.5% of the population and functioned to reduce inflammation. This polymorphism prevented HECTD2/PIAS1 nuclear interaction, thus preventing PIAS1 degradation. The HECTD2(A19P) polymorphism was also protective toward acute respiratory distress syndrome (ARDS). We then developed a small-molecule inhibitor, BC-1382, that targeted HECTD2 and attenuated lipopolysaccharide (LPS)- and Pseudomonas aeruginosa-induced lung inflammation. These studies describe an unreported innate immune pathway and suggest that mutation or antagonism of the E3 ligase HECTD2 results in reduced severity of lung inflammation by selectively modulating the abundance of the anti-inflammatory protein PIAS1.
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Affiliation(s)
- Tiffany A Coon
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Alison C McKelvey
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Travis Lear
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Shristi Rajbhandari
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Sarah R Dunn
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - William Connelly
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Joe Y Zhao
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - SeungHye Han
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Yuan Liu
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Nathaniel M Weathington
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Bryan J McVerry
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Yingze Zhang
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Bill B Chen
- Department of Medicine, Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, PA 15213, USA. Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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The linkage specificity determination of Ube2g2-gp78 mediated polyubiquitination. Biochem Biophys Res Commun 2016; 473:1139-1143. [PMID: 27067047 DOI: 10.1016/j.bbrc.2016.04.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 04/07/2016] [Indexed: 11/20/2022]
Abstract
Polyubiquitin chain linkage specificity or topology is essential for its role in diverse cellular processes. Previous studies pay more attentions to the linkage specificity of the first ubiquitin moieties, whereas, little is known about the editing mechanism of linkage specificity in longer polyubiquitin chains. gp78 and its cognate E2-Ube2g2 catalyze lysine48 (K48)-linked polyubiquitin chains to promote the degradation of targeted proteins. Here, we show that the linkage specificity of the entire polyubiquitin chain is determined by the conjugation manner of the first ubiquitin molecule but not the following ones. Further study discovered that the gp78 CUE domain works as a proofreading machine during the growth of K48-linked polyubiquitin chains to ensure the linkage specificity. Together, our studies uncover a novel mechanism underlying the linkage specificity determination of longer polyubiquitin chains.
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Wright FA, Wojcikiewicz RJH. Chapter 4 - Inositol 1,4,5-Trisphosphate Receptor Ubiquitination. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 141:141-59. [PMID: 27378757 DOI: 10.1016/bs.pmbts.2016.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP3Rs) are large (∼300kDa) proteins that associate into tetrameric ion channels in the endoplasmic reticulum (ER) membrane. Activation and opening of the channel upon binding of IP3 and Ca(2+) allows the flow of Ca(2+) ions from stores within the ER lumen to the cytosol, thereby promoting a number of Ca(2+)-dependent cellular events, such as secretion, neurotransmitter release, and cell division. Intriguingly, it appears that the same conformational change that IP3Rs undergo during activation makes them a target for degradation by the ubiquitin-proteasome pathway and that this mode of processing allows the cell to tune its internal Ca(2+) response to extracellular signals. Here, we review recent studies showing that activated IP3Rs interact with an array of proteins that mediate their degradation, that IP3Rs are modified by a complex array of ubiquitin conjugates, that this ubiquitination and degradation functions to regulate IP3-mediated Ca(2+) responses in the cell, and that mutations to different proteins involved in IP3R degradation result in a set of similar diseases.
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Affiliation(s)
- F A Wright
- Department of Pharmacology, SUNY Upstate Medical University, Syracuse, NY, United States
| | - R J H Wojcikiewicz
- Department of Pharmacology, SUNY Upstate Medical University, Syracuse, NY, United States.
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Abstract
Ubiquitin-conjugating enzymes (E2s) are the central players in the trio of enzymes responsible for the attachment of ubiquitin (Ub) to cellular proteins. Humans have ∼40 E2s that are involved in the transfer of Ub or Ub-like (Ubl) proteins (e.g., SUMO and NEDD8). Although the majority of E2s are only twice the size of Ub, this remarkable family of enzymes performs a variety of functional roles. In this review, we summarize common functional and structural features that define unifying themes among E2s and highlight emerging concepts in the mechanism and regulation of E2s.
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Biochemical and structural characterization of a novel ubiquitin-conjugating enzyme E2 from Agrocybe aegeria reveals Ube2w family-specific properties. Sci Rep 2015; 5:16056. [PMID: 26525192 PMCID: PMC4630614 DOI: 10.1038/srep16056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 10/01/2015] [Indexed: 11/08/2022] Open
Abstract
Ubiquitination is a post-translational modification that is involved in myriad cellar regulation and disease pathways. The ubiquitin-conjugating enzyme (E2) is an important player in the ubiquitin transfer pathway. Although many E2 structures are available, not all E2 families have known structures, and three-dimensional structures from fungal organisms other than yeast are lacking. We report here the crystal structure of UbcA1, which is a novel ubiquitin-conjugating enzyme identified from the edible and medicinal mushroom Agrocybe aegerita and displays potential antitumor properties. The protein belongs to the Ube2w family and shows similar biochemical characteristics to human Ube2w, including monomer-dimer equilibrium in solution, α-NH2 ubiquitin-transfer activity and a mechanism to recognize backbone atoms of intrinsically disordered N-termini in substrates. Its structure displays a unique C-terminal conformation with an orientation of helix α3 that is completely different from the reported E2 structures but similar to a recently reported NMR ensemble of Ube2w. A mutagenesis study on this novel enzyme revealed that an intact C-terminus is significant for protein dimerization and enzymatic activity. As the first crystallized full-length protein of this family, UbcA1 may supersede the truncated X-ray structure of Ube2w (PDB entry 2A7L) as the representative structure of the Ube2w family.
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40
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Choi YS, Kim EH, Ryu KS. Comparative studies on manual and automatic backbone chemical shift assignments of 2H/13C/15N-labeled Ube2g1. J Anal Sci Technol 2015. [DOI: 10.1186/s40543-015-0068-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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41
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Zhang T, Xu Y, Liu Y, Ye Y. gp78 functions downstream of Hrd1 to promote degradation of misfolded proteins of the endoplasmic reticulum. Mol Biol Cell 2015; 26:4438-50. [PMID: 26424800 PMCID: PMC4666138 DOI: 10.1091/mbc.e15-06-0354] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/22/2015] [Indexed: 11/16/2022] Open
Abstract
The functional relationship between mammalian ubiquitin ligase gp78 and Hrd1 was studied. Hrd1 is one of the essential retrotranslocation regulators conserved in yeast and mammalian cells, whereas gp78 serves an assisting role downstream of Hrd1 and possibly other ubiquitin ligases in mammalian cells. Eukaryotic cells eliminate misfolded proteins from the endoplasmic reticulum (ER) via a conserved process termed ER-associated degradation (ERAD). Central regulators of the ERAD system are membrane-bound ubiquitin ligases, which are thought to channel misfolded proteins through the ER membrane during retrotranslocation. Hrd1 and gp78 are mammalian ubiquitin ligases homologous to Hrd1p, an ubiquitin ligase essential for ERAD in Saccharomyces cerevisiae. However, the functional relevance of these proteins to Hrd1p is unclear. In this paper, we characterize the gp78-containing ubiquitin ligase complex and define its functional interplay with Hrd1 using biochemical and recently developed CRISPR-based genetic tools. Our data show that transient inactivation of the gp78 complex by short hairpin RNA–mediated gene silencing causes significant stabilization of both luminal and membrane ERAD substrates, but unlike Hrd1, which plays an essential role in retrotranslocation and ubiquitination of these ERAD substrates, knockdown of gp78 does not affect either of these processes. Instead, gp78 appears to act downstream of Hrd1 to promote ERAD via cooperation with the BAG6 chaperone complex. We conclude that the Hrd1 complex forms an essential retrotranslocation module that is evolutionarily conserved, but the mammalian ERAD system uses additional ubiquitin ligases to assist Hrd1 during retrotranslocation.
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Affiliation(s)
- Ting Zhang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Yue Xu
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Yanfen Liu
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Yihong Ye
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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42
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Zou X, Levy-Cohen G, Blank M. Molecular functions of NEDD4 E3 ubiquitin ligases in cancer. Biochim Biophys Acta Rev Cancer 2015; 1856:91-106. [DOI: 10.1016/j.bbcan.2015.06.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/12/2015] [Accepted: 06/23/2015] [Indexed: 02/08/2023]
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43
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Lu Y, Wang W, Kirschner MW. Specificity of the anaphase-promoting complex: a single-molecule study. Science 2015; 348:1248737. [PMID: 25859049 DOI: 10.1126/science.1248737] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 02/21/2015] [Indexed: 11/02/2022]
Abstract
Biological processes require specific enzymatic reactions, paradoxically involving short recognition sequences. As an example, cell-cycle timing depends on a sequence of ubiquitylation events mediated by the anaphase-promoting complex (APC) based on short redundant motifs. To understand the origin of specificity, we designed single-molecule fluorescence assays that capture transient ubiquitylation reactions. We find that the APC-mediated ubiquitylation involves a highly processive initial reaction on the substrate, followed by multiple encounters and reactions at a slower rate. The initial ubiquitylation greatly enhances the substrate's binding affinity in subsequent reactions, by both increasing the on-rate and decreasing the off-rate. We postulate that these cycles of positive feedback enable high specificity for substrates with short recognition motifs in a complex cellular environment.
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Affiliation(s)
- Ying Lu
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | - Weiping Wang
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | - Marc W Kirschner
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
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The HIP2~ubiquitin conjugate forms a non-compact monomeric thioester during di-ubiquitin synthesis. PLoS One 2015; 10:e0120318. [PMID: 25799589 PMCID: PMC4370575 DOI: 10.1371/journal.pone.0120318] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/05/2015] [Indexed: 11/30/2022] Open
Abstract
Polyubiquitination is a post-translational event used to control the degradation of damaged or unwanted proteins by modifying the target protein with a chain of ubiquitin molecules. One potential mechanism for the assembly of polyubiquitin chains involves the dimerization of an E2 conjugating enzyme allowing conjugated ubiquitin molecules to be put into close proximity to assist reactivity. HIP2 (UBE2K) and Ubc1 (yeast homolog of UBE2K) are unique E2 conjugating enzymes that each contain a C-terminal UBA domain attached to their catalytic domains, and they have basal E3-independent polyubiquitination activity. Although the isolated enzymes are monomeric, polyubiquitin formation activity assays show that both can act as ubiquitin donors or ubiquitin acceptors when in the activated thioester conjugate suggesting dimerization of the E2-ubiquitin conjugates. Stable disulfide complexes, analytical ultracentrifugation and small angle x-ray scattering were used to show that the HIP2-Ub and Ubc1-Ub thioester complexes remain predominantly monomeric in solution. Models of the HIP2-Ub complex derived from SAXS data show the complex is not compact but instead forms an open or backbent conformation similar to UbcH5b~Ub or Ubc13~Ub where the UBA domain and covalently attached ubiquitin reside on opposite ends of the catalytic domain. Activity assays showed that full length HIP2 exhibited a five-fold increase in the formation rate of di-ubiquitin compared to a HIP2 lacking the UBA domain. This difference was not observed for Ubc1 and may be attributed to the closer proximity of the UBA domain in HIP2 to the catalytic core than for Ubc1.
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45
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Kang T, Hao W, Niu Y, Luo Z, Jin G. Kinetic analysis of the weak affinity interaction between tris and lysozyme. Biochem Biophys Res Commun 2015; 457:659-63. [PMID: 25613863 DOI: 10.1016/j.bbrc.2015.01.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 01/11/2015] [Indexed: 12/21/2022]
Abstract
The biosensor based on total internal reflection imaging ellipsometry (TIRIE), regarded as an automotive real-time research approach for biomolecular interaction, is introduced to analyze the kinetic process of the weak interaction between tris and lysozyme. The experiment is performed by delivering lysozyme solution diluted to different concentrations to the biosensor substrate interface immobilized with tris. By applying pseudo-first-order interaction kinetics model, we are able to obtain the kinetic parameters from fitting experimental data. The calculated association rate constant and dissociation rate constant of tris and lysozyme interaction are in 10(-2) mol(-1) s(-1) and 10(3)s(-1) magnitude, respectively. To further improve TIRIE's ability for kinetically characterizing biomolecular interaction, a theoretical method to deduce associate rate constant before experiment is proposed.
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Affiliation(s)
- Tengfei Kang
- NML, Institution of Mechanics, Chinese Academy of Sciences, 15 Bei-si-huan West Road, Beijing 100190, China; University of the Chinese Academy of Sciences, 19 Yu-quan Road, Beijing 100049, China
| | - Wenxin Hao
- NML, Institution of Mechanics, Chinese Academy of Sciences, 15 Bei-si-huan West Road, Beijing 100190, China; University of the Chinese Academy of Sciences, 19 Yu-quan Road, Beijing 100049, China
| | - Yu Niu
- NML, Institution of Mechanics, Chinese Academy of Sciences, 15 Bei-si-huan West Road, Beijing 100190, China
| | - Ziren Luo
- NML, Institution of Mechanics, Chinese Academy of Sciences, 15 Bei-si-huan West Road, Beijing 100190, China
| | - Gang Jin
- NML, Institution of Mechanics, Chinese Academy of Sciences, 15 Bei-si-huan West Road, Beijing 100190, China.
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46
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Distinct activation of an E2 ubiquitin-conjugating enzyme by its cognate E3 ligases. Proc Natl Acad Sci U S A 2015; 112:E625-32. [PMID: 25646477 DOI: 10.1073/pnas.1415621112] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A significant portion of ubiquitin (Ub)-dependent cellular protein quality control takes place at the endoplasmic reticulum (ER) in a process termed "ER-associated degradation" (ERAD). Yeast ERAD employs two integral ER membrane E3 Ub ligases: Hrd1 (also termed "Der3") and Doa10, which recognize a distinct set of substrates. However, both E3s bind to and activate a common E2-conjugating enzyme, Ubc7. Here we describe a novel feature of the ERAD system that entails differential activation of Ubc7 by its cognate E3s. We found that residues within helix α2 of Ubc7 that interact with donor Ub were essential for polyUb conjugation. Mutagenesis of these residues inhibited the in vitro activity of Ubc7 by preventing the conjugation of donor Ub to the acceptor. Unexpectedly, Ub chain formation by mutant Ubc7 was restored selectively by the Hrd1 RING domain but not by the Doa10 RING domain. In agreement with the in vitro data, Ubc7 α2 helix mutations selectively impaired the in vivo degradation of Doa10 substrates but had no apparent effect on the degradation of Hrd1 substrates. To our knowledge, this is the first example of distinct activation requirements of a single E2 by two E3s. We propose a model in which the RING domain activates Ub transfer by stabilizing a transition state determined by noncovalent interactions between the α2 helix of Ubc7 and Ub and that this transition state may be stabilized further by some E3 ligases, such as Hrd1, through additional interactions outside the RING domain.
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47
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Choi YS, Lee YJ, Lee SY, Shi L, Ha JH, Cheong HK, Cheong C, Cohen RE, Ryu KS. Differential ubiquitin binding by the acidic loops of Ube2g1 and Ube2r1 enzymes distinguishes their Lys-48-ubiquitylation activities. J Biol Chem 2014; 290:2251-63. [PMID: 25471371 DOI: 10.1074/jbc.m114.624809] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ubiquitin E2 enzymes, Ube2g1 and Ube2r1, are able to synthesize Lys-48-linked polyubiquitins without an E3 ligase but how that is accomplished has been unclear. Although both E2s contain essential acidic loops, only Ube2r1 requires an additional C-terminal extension (184-196) for efficient Lys-48-ubiquitylation activity. The presence of Tyr-102 and Tyr-104 in the Ube2g1 acidic loop enhanced both ubiquitin binding and Lys-48-ubiquitylation and distinguished Ube2g1 from the otherwise similar truncated Ube2r1(1-183) (Ube2r1C). Replacement of Gln-105-Ser-106-Gly-107 in the acidic loop of Ube2r1C (Ube2r1C(YGY)) by the corresponding residues from Ube2g1 (Tyr-102-Gly-103-Tyr-104) increased Lys-48-ubiquitylation activity and ubiquitin binding. Two E2∼UB thioester mimics (oxyester and disulfide) were prepared to characterize the ubiquitin binding activity of the acidic loop. The oxyester but not the disulfide derivative was found to be a functional equivalent of the E2∼UB thioester. The ubiquitin moiety of the Ube2r1C(C93S)-[(15)N]UB(K48R) oxyester displayed two-state conformational exchange, whereas the Ube2r1C(C93S/YGY)-[(15)N]UB(K48R) oxyester showed predominantly one state. Together with NMR studies that compared UB(K48R) oxyesters of the wild-type and the acidic loop mutant (Y102G/Y104G) forms of Ube2g1, in vitro ubiquitylation assays with various mutation forms of the E2s revealed how the intramolecular interaction between the acidic loop and the attached donor ubiquitin regulates Lys-48-ubiquitylation activity.
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Affiliation(s)
- Yun-Seok Choi
- From the Division of Magnetic Resonance, Korea Basic Science Institute Ochang Campus, Cheongwon-Gun, Ochang-Eup, Yangcheong-Ri 804-1, Chungcheongbuk-Do 363-883, Department of Bio-Analytical Science, University of Science and Technology, Daejon 305-333, South Korea, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523-1870
| | - Yun-Ju Lee
- From the Division of Magnetic Resonance, Korea Basic Science Institute Ochang Campus, Cheongwon-Gun, Ochang-Eup, Yangcheong-Ri 804-1, Chungcheongbuk-Do 363-883
| | - Seo-Yeon Lee
- From the Division of Magnetic Resonance, Korea Basic Science Institute Ochang Campus, Cheongwon-Gun, Ochang-Eup, Yangcheong-Ri 804-1, Chungcheongbuk-Do 363-883
| | - Lei Shi
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, and
| | - Jung-Hye Ha
- From the Division of Magnetic Resonance, Korea Basic Science Institute Ochang Campus, Cheongwon-Gun, Ochang-Eup, Yangcheong-Ri 804-1, Chungcheongbuk-Do 363-883, Department of Bio-Analytical Science, University of Science and Technology, Daejon 305-333, South Korea
| | - Hae-Kap Cheong
- From the Division of Magnetic Resonance, Korea Basic Science Institute Ochang Campus, Cheongwon-Gun, Ochang-Eup, Yangcheong-Ri 804-1, Chungcheongbuk-Do 363-883
| | - Chaejoon Cheong
- From the Division of Magnetic Resonance, Korea Basic Science Institute Ochang Campus, Cheongwon-Gun, Ochang-Eup, Yangcheong-Ri 804-1, Chungcheongbuk-Do 363-883, Department of Bio-Analytical Science, University of Science and Technology, Daejon 305-333, South Korea
| | - Robert E Cohen
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523-1870
| | - Kyoung-Seok Ryu
- From the Division of Magnetic Resonance, Korea Basic Science Institute Ochang Campus, Cheongwon-Gun, Ochang-Eup, Yangcheong-Ri 804-1, Chungcheongbuk-Do 363-883, Department of Bio-Analytical Science, University of Science and Technology, Daejon 305-333, South Korea,
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Wang Y, Kim SM, Trnka MJ, Liu Y, Burlingame AL, Correia MA. Human liver cytochrome P450 3A4 ubiquitination: molecular recognition by UBC7-gp78 autocrine motility factor receptor and UbcH5a-CHIP-Hsc70-Hsp40 E2-E3 ubiquitin ligase complexes. J Biol Chem 2014; 290:3308-32. [PMID: 25451919 DOI: 10.1074/jbc.m114.611525] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
CYP3A4 is an abundant and catalytically dominant human liver endoplasmic reticulum-anchored cytochrome P450 enzyme engaged in the biotransformation of endo- and xenobiotics, including >50% of clinically relevant drugs. Alterations of CYP3A4 protein turnover can influence clinically relevant drug metabolism and bioavailability and drug-drug interactions. This CYP3A4 turnover involves endoplasmic reticulum-associated degradation via the ubiquitin (Ub)-dependent 26 S proteasomal system that relies on two highly complementary E2 Ub-conjugating-E3 Ub-ligase (UBC7-gp78 and UbcH5a-C terminus of Hsc70-interacting protein (CHIP)-Hsc70-Hsp40) complexes, as well as protein kinases (PK) A and C. We have documented that CYP3A4 Ser/Thr phosphorylation (Ser(P)/Thr(P)) by PKA and/or PKC accelerates/enhances its Lys ubiquitination by either of these E2-E3 systems. Intriguingly, CYP3A4 Ser(P)/Thr(P) and ubiquitinated Lys residues reside within the cytosol-accessible surface loop and/or conformationally assembled acidic Asp/Glu clusters, leading us to propose that such post-translational Ser/Thr protein phosphorylation primes CYP3A4 for ubiquitination. Herein, this possibility was examined through various complementary approaches, including site-directed mutagenesis, chemical cross-linking, peptide mapping, and LC-MS/MS analyses. Our findings reveal that such CYP3A4 Asp/Glu/Ser(P)/Thr(P) surface clusters are indeed important for its intermolecular electrostatic interactions with each of these E2-E3 subcomponents. By imparting additional negative charge to these Asp/Glu clusters, such Ser/Thr phosphorylation would generate P450 phosphodegrons for molecular recognition by the E2-E3 complexes, thereby controlling the timing of CYP3A4 ubiquitination and endoplasmic reticulum-associated degradation. Although the importance of phosphodegrons in the CHIP targeting of its substrates is known, to our knowledge this is the first example of phosphodegron involvement in gp78-substrate recruitment, an important step in CYP3A4 proteasomal degradation.
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Affiliation(s)
- YongQiang Wang
- From the Departments of Cellular and Molecular Pharmacology
| | - Sung-Mi Kim
- From the Departments of Cellular and Molecular Pharmacology
| | | | - Yi Liu
- From the Departments of Cellular and Molecular Pharmacology
| | | | - Maria Almira Correia
- From the Departments of Cellular and Molecular Pharmacology, Pharmaceutical Chemistry, and Bioengineering and Therapeutic Sciences, The Liver Center, University of California at San Francisco, San Francisco, California 94158-2517
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49
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gp78 elongates of polyubiquitin chains from the distal end through the cooperation of its G2BR and CUE domains. Sci Rep 2014; 4:7138. [PMID: 25409783 PMCID: PMC4238023 DOI: 10.1038/srep07138] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 11/05/2014] [Indexed: 01/01/2023] Open
Abstract
The modification of proteins with polyubiquitin chains alters their stability, localization and activity, thus regulating various aspects of cellular functions in eukaryotic cells. The ER quality control protein E3 gp78 catalyzes Lys48-linked polyubiquitin-chain- assembly on the Ube2g2 active site and is capable of transferring preassembled ubiquitin chains to its substrates. However, the underlying mechanism of polyubiquitin- chain-assembly remains elusive. Here, we demonstrate that the active site-linked ubiquitin chain is extended from the distal end by the cooperative actions of the G2BR and CUE domains of gp78. The G2BR domain is involved in ubiquitin chain synthesis by binding to the donor Ube2g2~Ub and promoting ubiquitin transfer from the E2 in cis. The CUE domain shows preferential binding to the ubiquitin chain compared to monoubiquitin and helps to position the distal ubiquitin in the correct orientation to attack the Ube2g2~Ub thioester bond. Our studies reveal that two interactions, one between the donor Ube2g2~Ub and the gp78 G2BR domain and another between the Ube2g2-linked ubiquitin chain and the gp78 CUE domain, cooperatively drive polyubiquitin-chain-assembly on the Ube2g2 active site.
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50
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Schweiger S, Dorn S, Fuchs M, Köhler A, Matthes F, Müller EC, Wanker E, Schneider R, Krauß S. The E3 ubiquitin ligase MID1 catalyzes ubiquitination and cleavage of Fu. J Biol Chem 2014; 289:31805-31817. [PMID: 25278022 PMCID: PMC4231658 DOI: 10.1074/jbc.m113.541219] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 10/01/2014] [Indexed: 11/06/2022] Open
Abstract
SHH (Sonic Hedgehog)-GLI signaling plays an important role during embryogenesis and in tumorigenesis. The survival and growth of several types of cancer depend on autonomously activated SHH-GLI signaling. A protein complex containing the ubiquitin ligase MID1 and protein phosphatase 2A regulates the nuclear localization and transcriptional activity of GLI3, a transcriptional effector molecule of SHH, in cancer cell lines with autonomously activated SHH signaling. However, the exact molecular mechanisms that mediate the interaction between MID1 and GLI3 remained unknown. Here, we show that MID1 catalyzes the ubiquitination and proteasomal cleavage of the GLI3 regulator Fu. Our data suggest that Fu ubiquitination and cleavage is one of the key elements connecting the MID1-PP2A protein complex with GLI3 activity control.
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Affiliation(s)
- Susann Schweiger
- Institute for Human Genetics, Medical School, University of Mainz, 55122 Mainz, Germany
| | - Stephanie Dorn
- German Center for Neurodegenerative Diseases, 53127 Bonn, Germany
| | - Melanie Fuchs
- Department of Dermatology, Charité University Hospital, 10117 Berlin, Germany
| | - Andrea Köhler
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, 6020 Innsbruck, Austria, and
| | - Frank Matthes
- German Center for Neurodegenerative Diseases, 53127 Bonn, Germany
| | | | - Erich Wanker
- Max Delbrück Center for Molecular Medicine, 13125 Berlin-Buch, Germany
| | - Rainer Schneider
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, 6020 Innsbruck, Austria, and
| | - Sybille Krauß
- German Center for Neurodegenerative Diseases, 53127 Bonn, Germany,.
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