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Kaiho-Soma A, Akizuki Y, Igarashi K, Endo A, Shoda T, Kawase Y, Demizu Y, Naito M, Saeki Y, Tanaka K, Ohtake F. TRIP12 promotes small-molecule-induced degradation through K29/K48-branched ubiquitin chains. Mol Cell 2021; 81:1411-1424.e7. [PMID: 33567268 DOI: 10.1016/j.molcel.2021.01.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/13/2020] [Accepted: 01/20/2021] [Indexed: 12/19/2022]
Abstract
Targeted protein degradation is an emerging therapeutic paradigm. Small-molecule degraders such as proteolysis-targeting chimeras (PROTACs) induce the degradation of neo-substrates by hijacking E3 ubiquitin ligases. Although ubiquitylation of endogenous substrates has been extensively studied, the mechanism underlying forced degradation of neo-substrates is less well understood. We found that the ubiquitin ligase TRIP12 promotes PROTAC-induced and CRL2VHL-mediated degradation of BRD4 but is dispensable for the degradation of the endogenous CRL2VHL substrate HIF-1α. TRIP12 associates with BRD4 via CRL2VHL and specifically assembles K29-linked ubiquitin chains, facilitating the formation of K29/K48-branched ubiquitin chains and accelerating the assembly of K48 linkage by CRL2VHL. Consequently, TRIP12 promotes the PROTAC-induced apoptotic response. TRIP12 also supports the efficiency of other degraders that target CRABP2 or TRIM24 or recruit CRBN. These observations define TRIP12 and K29/K48-branched ubiquitin chains as accelerators of PROTAC-directed targeted protein degradation, revealing a cooperative mechanism of branched ubiquitin chain assembly unique to the degradation of neo-substrates.
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Affiliation(s)
- Ai Kaiho-Soma
- Institute for Advanced Life Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Yoshino Akizuki
- School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Katsuhide Igarashi
- Institute for Advanced Life Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Akinori Endo
- Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Takuji Shoda
- Division of Organic Chemistry, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki city, Kanagawa 210-9501, Japan
| | - Yasuko Kawase
- Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Yosuke Demizu
- Division of Organic Chemistry, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki city, Kanagawa 210-9501, Japan
| | - Mikihiko Naito
- Division of Organic Chemistry, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki city, Kanagawa 210-9501, Japan; Division of Molecular Target and Gene Therapy Products, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki city, Kanagawa 210-9501, Japan
| | - Yasushi Saeki
- Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Keiji Tanaka
- Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Fumiaki Ohtake
- Institute for Advanced Life Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; Protein Metabolism Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Inhibition of p38 Mitogen-Activated Protein Kinase Ameliorates HAP40 Depletion-Induced Toxicity and Proteasomal Defect in Huntington's Disease Model. Mol Neurobiol 2021; 58:2704-2723. [PMID: 33492644 DOI: 10.1007/s12035-020-02280-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 12/30/2020] [Indexed: 02/07/2023]
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder caused by an expansion of polyglutamine stretch (polyQ) at the N-terminus of huntingtin (Htt) protein. The abnormally expanded polyQ stretch of mutant Htt makes it prone to aggregate, leading to neuropathology. HAP40 is a 40-kDa huntingtin-associated protein with undefined functions. HAP40 protein has been shown to increase in HD patients and HD mouse model cells. However, recent proteomic analysis provides new evidence that HAP40 protein is decreased in the striatum of HD knockin model mice. In this study, we developed HAP40-specific antibody and showed that both HAP40 mRNA and its encoded protein were reduced in HD striatal neuronal STHDHQ111/Q111 cells. Depletion of endogenous HAP40 led to cytotoxicity that was linked to increased accumulation of aggregated and soluble forms of mutant Htt, which recapitulates HD pathology. Moreover, we found that HAP40 depletion reduced the proteasomal chymotrypsin-like activity and increased the autophagic flux. Importantly, inhibition of p38 MAPK pathway by PD169316 increased chymotrypsin-like activity and reduced accumulation of aggregated and soluble forms of mutant Htt in HAP40-depleted cells to alleviate HAP40-depletion induced cytotoxicity. Taken together, our results suggest that modulation of p38 MAPK-mediated proteasomal peptidase activity may provide a new therapeutic target to restore proteostasis in neurodegenerative diseases.
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53
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Regulation of Treg Functions by the Ubiquitin Pathway. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1278:47-62. [PMID: 33523442 DOI: 10.1007/978-981-15-6407-9_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Regulatory T (Tregs) cells, required to maintain immune homeostasis, have significant power in disease outcomes. Treg dysfunction, predominantly characterized by the loss of the master transcription factor FoxP3 and the acquisition of Teff-like phenotypes, can promote autoimmunity as well as enhance anti-tumor immunity. As FoxP3 expression and stability are pinnacle for Treg suppressive functions, understanding the pathways that regulate FoxP3 is crucial to ascertain Treg-mediated therapies for autoimmune diseases and cancer. Mechanisms controlling FoxP3 expression and stability range from transcriptional to posttranslational, revealing multiple therapeutic opportunities. While many of the transcriptional pathways have been explored in detail, a recent surge in interest on the posttranslational mechanisms regulating FoxP3 has arisen. Particularly, the role of ubiquitination on Tregs both directly and indirectly involving FoxP3 has gained interest. Here, we summarize the current knowledge on ubiquitin-dependent, FoxP3-mediated control of Treg function as it pertains to human diseases.
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Harris LD, Le Pen J, Scholz N, Mieszczanek J, Vaughan N, Davis S, Berridge G, Kessler BM, Bienz M, Licchesi JDF. The deubiquitinase TRABID stabilizes the K29/K48-specific E3 ubiquitin ligase HECTD1. J Biol Chem 2021; 296:100246. [PMID: 33853758 PMCID: PMC7948964 DOI: 10.1074/jbc.ra120.015162] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 12/23/2020] [Accepted: 12/30/2020] [Indexed: 12/18/2022] Open
Abstract
Ubiquitin is a versatile posttranslational modification, which is covalently attached to protein targets either as a single moiety or as a ubiquitin chain. In contrast to K48 and K63-linked chains, which have been extensively studied, the regulation and function of most atypical ubiquitin chains are only starting to emerge. The deubiquitinase TRABID/ZRANB1 is tuned for the recognition and cleavage of K29 and K33-linked chains. Yet, substrates of TRABID and the cellular functions of these atypical ubiquitin signals remain unclear. We determined the interactome of two TRABID constructs rendered catalytic dead either through a point mutation in the catalytic cysteine residue or through removal of the OTU catalytic domain. We identified 50 proteins trapped by both constructs and which therefore represent candidate substrates of TRABID. The E3 ubiquitin ligase HECTD1 was then validated as a substrate of TRABID and used UbiCREST and Ub-AQUA proteomics to show that HECTD1 preferentially assembles K29- and K48-linked ubiquitin chains. Further in vitro autoubiquitination assays using ubiquitin mutants established that while HECTD1 can assemble short homotypic K29 and K48-linked chains, it requires branching at K29/K48 in order to achieve its full ubiquitin ligase activity. We next used transient knockdown and genetic knockout of TRABID in mammalian cells in order to determine the functional relationship between TRABID and HECTD1. This revealed that upon TRABID depletion, HECTD1 is readily degraded. Thus, this study identifies HECTD1 as a mammalian E3 ligase that assembles branched K29/K48 chains and also establishes TRABID-HECTD1 as a DUB/E3 pair regulating K29 linkages.
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Affiliation(s)
- Lee D Harris
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Janic Le Pen
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Nico Scholz
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Juliusz Mieszczanek
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Natalie Vaughan
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Simon Davis
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Georgina Berridge
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Benedikt M Kessler
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Mariann Bienz
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Julien D F Licchesi
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom.
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55
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Saha S, Sun Y, Huang SYN, Baechler SA, Pongor LS, Agama K, Jo U, Zhang H, Tse-Dinh YC, Pommier Y. DNA and RNA Cleavage Complexes and Repair Pathway for TOP3B RNA- and DNA-Protein Crosslinks. Cell Rep 2020; 33:108569. [PMID: 33378676 PMCID: PMC7859927 DOI: 10.1016/j.celrep.2020.108569] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 11/20/2020] [Accepted: 12/07/2020] [Indexed: 12/31/2022] Open
Abstract
The present study demonstrates that topoisomerase 3B (TOP3B) forms both RNA and DNA cleavage complexes (TOP3Bccs) in vivo and reveals a pathway for repairing TOP3Bccs. For inducing and detecting cellular TOP3Bccs, we engineer a “self-trapping” mutant of TOP3B (R338W-TOP3B). Transfection with R338W-TOP3B induces R-loops, genomic damage, and growth defect, which highlights the importance of TOP3Bcc repair mechanisms. To determine how cells repair TOP3Bccs, we deplete tyrosyl-DNA phosphodiesterases (TDP1 and TDP2). TDP2-deficient cells show elevated TOP3Bccs both in DNA and RNA. Conversely, overexpression of TDP2 lowers cellular TOP3Bccs. Using recombinant human TDP2, we demonstrate that TDP2 can process both denatured and proteolyzed TOP3Bccs. We also show that cellular TOP3Bccs are ubiquitinated by the E3 ligase TRIM41 before undergoing proteasomal processing and excision by TDP2. Saha et al. introduce an approach to generate and detect the catalytic intermediates of TOP3B in DNA and RNA by engineering a self-poisoning enzyme, R338W-TOP3B. They reveal the cellular consequences of abortive TOP3Bcc formation and a repair pathway involving TRIM41, the proteasome, and TDP2 for processing of TOP3Bcc.
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Affiliation(s)
- Sourav Saha
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Yilun Sun
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Shar-Yin Naomi Huang
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Simone Andrea Baechler
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Lorinc Sandor Pongor
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Keli Agama
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Ukhyun Jo
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Hongliang Zhang
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Yuk-Ching Tse-Dinh
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA; Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Yves Pommier
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
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56
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Scholz N, Kurian KM, Siebzehnrubl FA, Licchesi JDF. Targeting the Ubiquitin System in Glioblastoma. Front Oncol 2020; 10:574011. [PMID: 33324551 PMCID: PMC7724090 DOI: 10.3389/fonc.2020.574011] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022] Open
Abstract
Glioblastoma is the most common primary brain tumor in adults with poor overall outcome and 5-year survival of less than 5%. Treatment has not changed much in the last decade or so, with surgical resection and radio/chemotherapy being the main options. Glioblastoma is highly heterogeneous and frequently becomes treatment-resistant due to the ability of glioblastoma cells to adopt stem cell states facilitating tumor recurrence. Therefore, there is an urgent need for novel therapeutic strategies. The ubiquitin system, in particular E3 ubiquitin ligases and deubiquitinating enzymes, have emerged as a promising source of novel drug targets. In addition to conventional small molecule drug discovery approaches aimed at modulating enzyme activity, several new and exciting strategies are also being explored. Among these, PROteolysis TArgeting Chimeras (PROTACs) aim to harness the endogenous protein turnover machinery to direct therapeutically relevant targets, including previously considered "undruggable" ones, for proteasomal degradation. PROTAC and other strategies targeting the ubiquitin proteasome system offer new therapeutic avenues which will expand the drug development toolboxes for glioblastoma. This review will provide a comprehensive overview of E3 ubiquitin ligases and deubiquitinating enzymes in the context of glioblastoma and their involvement in core signaling pathways including EGFR, TGF-β, p53 and stemness-related pathways. Finally, we offer new insights into how these ubiquitin-dependent mechanisms could be exploited therapeutically for glioblastoma.
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Affiliation(s)
- Nico Scholz
- Department of Biology & Biochemistry, University of Bath, Bath, United Kingdom
| | - Kathreena M. Kurian
- Brain Tumour Research Group, Institute of Clinical Neurosciences, University of Bristol, Bristol, United Kingdom
| | - Florian A. Siebzehnrubl
- Cardiff University School of Biosciences, European Cancer Stem Cell Research Institute, Cardiff, United Kingdom
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57
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Brunet M, Vargas C, Larrieu D, Torrisani J, Dufresne M. E3 Ubiquitin Ligase TRIP12: Regulation, Structure, and Physiopathological Functions. Int J Mol Sci 2020; 21:ijms21228515. [PMID: 33198194 PMCID: PMC7697007 DOI: 10.3390/ijms21228515] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023] Open
Abstract
The Thyroid hormone Receptor Interacting Protein 12 (TRIP12) protein belongs to the 28-member Homologous to the E6-AP C-Terminus (HECT) E3 ubiquitin ligase family. First described as an interactor of the thyroid hormone receptor, TRIP12’s biological importance was revealed by the embryonic lethality of a murine model bearing an inactivating mutation in the TRIP12 gene. Further studies showed the participation of TRIP12 in the regulation of major biological processes such as cell cycle progression, DNA damage repair, chromatin remodeling, and cell differentiation by an ubiquitination-mediated degradation of key protein substrates. Moreover, alterations of TRIP12 expression have been reported in cancers that can serve as predictive markers of therapeutic response. The TRIP12 gene is also referenced as a causative gene associated to intellectual disorders such as Clark–Baraitser syndrome and is clearly implicated in Autism Spectrum Disorder. The aim of the review is to provide an exhaustive and integrated overview of the different aspects of TRIP12 ranging from its regulation, molecular functions and physio-pathological implications.
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Affiliation(s)
- Manon Brunet
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
| | - Claire Vargas
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
| | - Dorian Larrieu
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
| | - Jérôme Torrisani
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
- Correspondence: (J.T.); (M.D.); Tel.: +33-582-741-644 (J.T.); +33-582-741-643 (M.D.)
| | - Marlène Dufresne
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
- Correspondence: (J.T.); (M.D.); Tel.: +33-582-741-644 (J.T.); +33-582-741-643 (M.D.)
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58
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Wang YS, Wu KP, Jiang HK, Kurkute P, Chen RH. Branched Ubiquitination: Detection Methods, Biological Functions and Chemical Synthesis. Molecules 2020; 25:E5200. [PMID: 33182242 PMCID: PMC7664869 DOI: 10.3390/molecules25215200] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 11/05/2020] [Accepted: 11/07/2020] [Indexed: 11/16/2022] Open
Abstract
Ubiquitination is a versatile posttranslational modification that elicits signaling roles to impact on various cellular processes and disease states. The versatility is a result of the complexity of ubiquitin conjugates, ranging from a single ubiquitin monomer to polymers with different length and linkage types. Recent studies have revealed the abundant existence of branched ubiquitin chains in which one ubiquitin molecule is connected to two or more ubiquitin moieties in the same ubiquitin polymer. Compared to the homotypic ubiquitin chain, the branched chain is recognized or processed differently by readers and erasers of the ubiquitin system, respectively, resulting in a qualitative or quantitative alteration of the functional output. Furthermore, certain types of branched ubiquitination are induced by cellular stresses, implicating their important physiological role in stress adaption. In addition, the current chemical methodologies of solid phase peptide synthesis and expanding genetic code approach have been developed to synthesize different architectures of branched ubiquitin chains. The synthesized branched ubiquitin chains have shown their significance in understanding the topologies and binding partners of the branched chains. Here, we discuss the recent progresses on the detection, functional characterization and synthesis of branched ubiquitin chains as well as the future perspectives of this emerging field.
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Affiliation(s)
- Yane-Shih Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan; (H.-K.J.); (P.K.)
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
| | - Kuen-Phon Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan; (H.-K.J.); (P.K.)
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Han-Kai Jiang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan; (H.-K.J.); (P.K.)
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu 30044, Taiwan
| | - Prashant Kurkute
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan; (H.-K.J.); (P.K.)
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Ruey-Hwa Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan; (H.-K.J.); (P.K.)
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
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59
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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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60
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Schneider SM, Lee BH, Nicola AV. Viral entry and the ubiquitin-proteasome system. Cell Microbiol 2020; 23:e13276. [PMID: 33037857 DOI: 10.1111/cmi.13276] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 09/17/2020] [Accepted: 09/19/2020] [Indexed: 02/06/2023]
Abstract
Viruses confiscate cellular components of the ubiquitin-proteasome system (UPS) to facilitate many aspects of the infectious cycle. The 26S proteasome is an ATP-dependent, multisubunit proteolytic machine present in all eukaryotic cells. The proteasome executes the controlled degradation of functional proteins, as well as the hydrolysis of aberrantly folded polypeptides. There is growing evidence for the role of the UPS in viral entry. The UPS assists in several steps of the initiation of infection, including endosomal escape of the entering virion, intracellular transport of incoming nucleocapsids and uncoating of the viral genome. Inhibitors of proteasome activity, including MG132, epoxomicin, lactacystin and bortezomib have been integral to developments in this area. Here, we review the mechanistic details of UPS involvement in the entry process of viruses from a multitude of families. The possibility of proteasome inhibitors as therapeutic antiviral agents is highlighted.
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Affiliation(s)
- Seth M Schneider
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA.,School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Becky H Lee
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Anthony V Nicola
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA.,School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
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61
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Sulkshane P, Duek I, Ram J, Thakur A, Reis N, Ziv T, Glickman MH. Inhibition of proteasome reveals basal mitochondrial ubiquitination. J Proteomics 2020; 229:103949. [PMID: 32882436 DOI: 10.1016/j.jprot.2020.103949] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 08/18/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023]
Abstract
Strict quality control for mitochondrial proteins is necessary to ensure cell homeostasis. Two cellular pathways-Ubiquitin Proteasome System (UPS) and autophagy-contribute to mitochondrial homeostasis under stressful conditions. Here, we investigate changes to the mitochondria proteome and to the ubiquitin landscape at mitochondria in response to proteasome inhibition. Treatment of HeLa cells devoid of Parkin, the primary E3 ligase responsible for mitophagy, with proteasome inhibitor MG132 for a few hours caused mitochondrial oxidative stress and fragmentation, reduced energy output, and increased mitochondrial ubiquitination without inducing mitophagy. Overexpression of Parkin did not show any induction of mitophagy in response to MG132 treatment. Analysis of ubiquitin chains on isolated mitochondria revealed predominance of K48, K29 and K63-linked polyubiquitin. Interestingly, of all ubiquitinated mitochondrial proteins detected in response to MG132 treatment, a majority (≥90%) were intramitochondrial irrespective of Parkin expression. However, overall levels of these ubiquitinated mitochondrial proteins did not change significantly upon proteasome inhibition when evaluated by quantitative proteomics (LFQ and SILAC), suggesting that only a small portion are ubiquitinated under basal conditions. Another aspect of proteasome inhibition is significant enrichment of UPS, lysosomal and phagosomal components, and other heat shock proteins associated with isolated mitochondria. Taken together, our study highlights a critical role of UPS for ubiquitinating and removing imported proteins as part of a basal mitochondrial quality control system independent of Parkin. SIGNIFICANCE: As centers of cellular bioenergetics, numerous metabolic pathways and signaling cascades, the health of mitochondria is of utmost importance for ensuring cell survival. Due to their unique physiology, mitochondria are constantly subjected to damaging oxidative radicals (ROS) and protein import-related stress due to buildup of unfolded aggregate-prone proteins. Thus, for quality control purposes, mitochondria are constantly under surveillance by Autophagy and the Ubiquitin Proteasome System (UPS), both of which share ubiquitin as a common signal. The ubiquitin landscape of mitochondria has been studied in detail under stressful conditions, however, little is known about basal mitochondrial ubiquitination. Our study reveals that the extent of ubiquitination at mitochondria greatly increases upon proteasome inhibition, pointing to a large number of potential substrates for proteasomal degradation. Interestingly, most of the ubiquitination occurs on intramitochondrial proteins, components of the electron transport chain (ETC) and matrix-resident metabolic enzymes in particular. Moreover, numerous cytosolic UPS components, chaperones and autophagy-lysosomal proteins were recruited to mitochondria upon proteasome inhibition. Taken together, this suggests that the levels and functions of mitochondrial proteins are constantly regulated through ubiquitin-dependent proteasomal degradation even under basal conditions. Unclogging mitochondrial import channels may provide a mechanism to alleviate stress associated with mitochondrial protein import or to adapt cells according to their metabolic needs. Therefore, targeting the mitochondrial ubiquitination/deubiquitination machinery, such as improving the therapeutic potency of proteasome inhibitors, may provide an additional therapeutic arsenal against tumors.
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Affiliation(s)
- Prasad Sulkshane
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Inbar Duek
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Jonathan Ram
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Anita Thakur
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Noa Reis
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Tamar Ziv
- The Smoler Protein Research Center, Technion Israel Institute of Technology, Haifa 32000, Israel.
| | - Michael H Glickman
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel.
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Pais P, Califórnia R, Galocha M, Viana R, Ola M, Cavalheiro M, Takahashi-Nakaguchi A, Chibana H, Butler G, Teixeira MC. Candida glabrata Transcription Factor Rpn4 Mediates Fluconazole Resistance through Regulation of Ergosterol Biosynthesis and Plasma Membrane Permeability. Antimicrob Agents Chemother 2020; 64:e00554-20. [PMID: 32571817 PMCID: PMC7449212 DOI: 10.1128/aac.00554-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 06/13/2020] [Indexed: 01/05/2023] Open
Abstract
The ability to acquire azole resistance is an emblematic trait of the fungal pathogen Candida glabrata Understanding the molecular basis of azole resistance in this pathogen is crucial for designing more suitable therapeutic strategies. This study shows that the C. glabrata transcription factor (TF) CgRpn4 is a determinant of azole drug resistance. RNA sequencing during fluconazole exposure revealed that CgRpn4 regulates the expression of 212 genes, activating 80 genes and repressing, likely in an indirect fashion, 132 genes. Targets comprise several proteasome and ergosterol biosynthesis genes, including ERG1, ERG2, ERG3, and ERG11 The localization of CgRpn4 to the nucleus increases upon fluconazole stress. Consistent with a role in ergosterol and plasma membrane homeostasis, CgRpn4 is required for the maintenance of ergosterol levels upon fluconazole stress, which is associated with a role in the upkeep of cell permeability and decreased intracellular fluconazole accumulation. We provide evidence that CgRpn4 directly regulates ERG11 expression through the TTGCAAA binding motif, reinforcing the relevance of this regulatory network in azole resistance. In summary, CgRpn4 is a new regulator of the ergosterol biosynthesis pathway in C. glabrata, contributing to plasma membrane homeostasis and, thus, decreasing azole drug accumulation.
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Affiliation(s)
- Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal
| | - Raquel Califórnia
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal
| | - Mónica Galocha
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal
| | - Romeu Viana
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal
| | - Mihaela Ola
- School of Biomedical and Biomolecular Sciences, Conway Institute, University College Dublin, Dublin, Ireland
| | - Mafalda Cavalheiro
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal
| | | | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Geraldine Butler
- School of Biomedical and Biomolecular Sciences, Conway Institute, University College Dublin, Dublin, Ireland
| | - Miguel C Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal
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Disome and Trisome Profiling Reveal Genome-wide Targets of Ribosome Quality Control. Mol Cell 2020; 79:588-602.e6. [PMID: 32615089 DOI: 10.1016/j.molcel.2020.06.010] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 04/07/2020] [Accepted: 06/02/2020] [Indexed: 01/18/2023]
Abstract
The ribosome-associated protein quality control (RQC) system that resolves stalled translation events is activated when ribosomes collide and form disome, trisome, or higher-order complexes. However, it is unclear whether this system distinguishes collision complexes formed on defective mRNAs from those with functional roles on endogenous transcripts. Here, we performed disome and trisome footprint profiling in yeast and found collisions were enriched on diverse sequence motifs known to slow translation. When 60S recycling was inhibited, disomes accumulated at stop codons and could move into the 3' UTR to reinitiate translation. The ubiquitin ligase and RQC factor Hel2/ZNF598 generally recognized collisions but did not induce degradation of endogenous transcripts. However, loss of Hel2 triggered the integrated stress response, via phosphorylation of eIF2α, thus linking these pathways. Our results suggest that Hel2 has a role in sensing ribosome collisions on endogenous mRNAs, and such events may be important for cellular homeostasis.
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64
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Davis PR, Miller SG, Verhoeven NA, Morgan JS, Tulis DA, Witczak CA, Brault JJ. Increased AMP deaminase activity decreases ATP content and slows protein degradation in cultured skeletal muscle. Metabolism 2020; 108:154257. [PMID: 32370945 PMCID: PMC7319876 DOI: 10.1016/j.metabol.2020.154257] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/18/2020] [Accepted: 04/29/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Protein degradation is an energy-dependent process, requiring ATP at multiple steps. However, reports conflict as to the relationship between intracellular energetics and the rate of proteasome-mediated protein degradation. METHODS To determine whether the concentration of the adenine nucleotide pool (ATP + ADP + AMP) affects protein degradation in muscle cells, we overexpressed an AMP degrading enzyme, AMP deaminase 3 (AMPD3), via adenovirus in C2C12 myotubes. RESULTS Overexpression of AMPD3 resulted in a dose- and time-dependent reduction of total adenine nucleotides (ATP, ADP and AMP) without increasing the ADP/ATP or AMP/ATP ratios. In agreement, the reduction of total adenine nucleotide concentration did not result in increased Thr172 phosphorylation of AMP-activated protein kinase (AMPK), a common indicator of intracellular energetic state. Furthermore, LC3 protein accumulation and ULK1 (Ser 555) phosphorylation were not induced. However, overall protein degradation and ubiquitin-dependent proteolysis were slowed by overexpression of AMPD3, despite unchanged content of several proteasome subunit proteins and proteasome activity in vitro under standard conditions. CONCLUSIONS Altogether, these findings indicate that a physiologically relevant decrease in ATP content, without a concomitant increase in ADP or AMP, is sufficient to decrease the rate of protein degradation and activity of the ubiquitin-proteasome system in muscle cells. This suggests that adenine nucleotide degrading enzymes, such as AMPD3, may be a viable target to control muscle protein degradation and perhaps muscle mass.
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Affiliation(s)
- Patrick R Davis
- Department of Kinesiology, East Carolina University, United States of America
| | - Spencer G Miller
- Department of Kinesiology, East Carolina University, United States of America
| | - Nicolas A Verhoeven
- Department of Kinesiology, East Carolina University, United States of America
| | - Joshua S Morgan
- Department of Physiology, Brody School of Medicine, East Carolina University, United States of America
| | - David A Tulis
- Department of Physiology, Brody School of Medicine, East Carolina University, United States of America
| | - Carol A Witczak
- Department of Kinesiology, East Carolina University, United States of America; Department of Physiology, Brody School of Medicine, East Carolina University, United States of America; Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States of America
| | - Jeffrey J Brault
- Department of Kinesiology, East Carolina University, United States of America; Department of Physiology, Brody School of Medicine, East Carolina University, United States of America; Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States of America.
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65
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Sharma B, Taganna J. Genome-wide analysis of the U-box E3 ubiquitin ligase enzyme gene family in tomato. Sci Rep 2020; 10:9581. [PMID: 32533036 PMCID: PMC7293263 DOI: 10.1038/s41598-020-66553-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 05/18/2020] [Indexed: 12/15/2022] Open
Abstract
E3 ubiquitin ligases are a central modifier of plant signaling pathways that act through targeting proteins to the degradation pathway. U-box E3 ubiquitin ligases are a distinct class of E3 ligases that utilize intramolecular interactions for its scaffold stabilization. U-box E3 ubiquitin ligases are prevalent in plants in comparison to animals. However, the evolutionary aspects, genetic organizations, and functional fate of the U-box E3 gene family in plant development, especially in tomato is not well understood. In the present study, we have performed in-silico genome-wide analysis of the U-box E3 ubiquitin ligase gene family in Solanum lycopersicum. We have identified 62 U-box genes with U-box/Ub Fusion Degradation 2 (UFD2) domain. The chromosomal localization, phylogenetic analysis, gene structure, motifs, gene duplication, syntenic regions, promoter, physicochemical properties, and ontology were investigated. The U-box gene family showed significant conservation of the U-box domain throughout the gene family. Duplicated genes discerned noticeable functional transitions among duplicated genes. The gene expression profiles of U-box E3 family members show involvement in abiotic and biotic stress signaling as well as hormonal pathways. We found remarkable participation of the U-box gene family in the vegetative and reproductive tissue development. It is predicted to be actively regulating flowering time and endosperm formation. Our study provides a comprehensive picture of distribution, structural features, promoter elements, evolutionary relationship, and gene expression of the U-box gene family in the tomato. We predict the crucial participation of the U-box gene family in tomato plant development and stress responses.
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Affiliation(s)
- Bhaskar Sharma
- TERI School of Advanced Studies, 10 Institutional Area, Vasant Kunj, New Delhi, Delhi, 110070, India.
- School of Life and Environmental Sciences, Faculty of Science, Engineering, and Built Environment, Deakin University, Geelong, VIC-3220, Australia.
| | - Joemar Taganna
- SciBiz Informatics, 2/F Unit 3 CFI Building, Maharlika Highway, Brgy. Guindapunan, Palo, Leyte, 6501, Philippines
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66
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Tranter D, Filipuzzi I, Lochmann T, Knapp B, Kellosalo J, Estoppey D, Pistorius D, Meissner A, Paavilainen VO, Hoepfner D. Kendomycin Cytotoxicity against Bacterial, Fungal, and Mammalian Cells Is Due to Cation Chelation. JOURNAL OF NATURAL PRODUCTS 2020; 83:965-971. [PMID: 32182062 PMCID: PMC7497661 DOI: 10.1021/acs.jnatprod.9b00826] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Indexed: 06/10/2023]
Abstract
Kendomycin is a small-molecule natural product that has gained significant attention due to reported cytotoxicity against pathogenic bacteria and fungi as well as a number of cancer cell lines. Despite significant biomedical interest and attempts to reveal its mechanism of action, the cellular target of kendomycin remains disputed. Herein it is shown that kendomycin induces cellular responses indicative of cation stress comparable to the effects of established iron chelators. Furthermore, addition of excess iron and copper attenuated kendomycin cytotoxicity in bacteria, yeast, and mammalian cells. Finally, NMR analysis demonstrated a direct interaction with cations, corroborating a close link between the observed kendomycin polypharmacology across different species and modulation of iron and/or copper levels.
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Affiliation(s)
- Dale Tranter
- Institute
of Biotechnology, University of Helsinki, Helsinki, 00014, Finland
| | - Ireos Filipuzzi
- Novartis
Institutes for BioMedical Research, 4056 Basel, Switzerland
| | - Thomas Lochmann
- Novartis
Institutes for BioMedical Research, 4056 Basel, Switzerland
| | - Britta Knapp
- Novartis
Institutes for BioMedical Research, 4056 Basel, Switzerland
| | - Juho Kellosalo
- Institute
of Biotechnology, University of Helsinki, Helsinki, 00014, Finland
| | - David Estoppey
- Novartis
Institutes for BioMedical Research, 4056 Basel, Switzerland
| | - Dominik Pistorius
- Novartis
Institutes for BioMedical Research, 4056 Basel, Switzerland
| | - Axel Meissner
- Novartis
Institutes for BioMedical Research, 4056 Basel, Switzerland
| | | | - Dominic Hoepfner
- Novartis
Institutes for BioMedical Research, 4056 Basel, Switzerland
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67
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Gierisch ME, Giovannucci TA, Dantuma NP. Reporter-Based Screens for the Ubiquitin/Proteasome System. Front Chem 2020; 8:64. [PMID: 32117887 PMCID: PMC7026131 DOI: 10.3389/fchem.2020.00064] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 01/20/2020] [Indexed: 01/14/2023] Open
Abstract
Instant and adequate handling of misfolded or otherwise aberrant proteins is of paramount importance for maintaining protein homeostasis in cells. The ubiquitin/proteasome system (UPS) is a central player in protein quality control as it operates in a seek-and-destroy mode, thereby facilitating elimination of faulty proteins. While proteasome inhibition is in clinical use for the treatment of hematopoietic malignancies, stimulation of the UPS has been proposed as a potential therapeutic strategy for various neurodegenerative disorders. High-throughput screens using genetic approaches or compound libraries are powerful tools to identify therapeutic intervention points and novel drugs. Unlike assays that measure specific activities of components of the UPS, reporter substrates provide us with a more holistic view of the general functional status of the UPS in cells. As such, reporter substrates can reveal new ways to obstruct or stimulate this critical proteolytic pathway. Here, we discuss various reporter substrates for the UPS and their application in the identification of key players and the pursuit for novel therapeutics.
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Affiliation(s)
- Maria E Gierisch
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | | | - Nico P Dantuma
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
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68
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Figuerola-Conchas A, Saarbach J, Daguer JP, Cieren A, Barluenga S, Winssinger N, Gotta M. Small-Molecule Modulators of the ATPase VCP/p97 Affect Specific p97 Cellular Functions. ACS Chem Biol 2020; 15:243-253. [PMID: 31790201 DOI: 10.1021/acschembio.9b00832] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
VCP/p97 belongs to the AAA+ ATPase family and has an essential role in several cellular processes ranging from cell division to protein homeostasis. Compounds targeting p97 inhibit the main ATPase domain and cause cell death. Here, using PNA-encoded chemical libraries, we have identified two small molecules that target the regulatory domain of p97, comprising the N-terminal and the D1 ATPase domains, and do not cause cell death. One molecule, NW1028, inhibits the degradation of a p97-dependent reporter, whereas the other, NW1030, increases it. ATPase assays show that NW1028 and NW1030 do not affect the main catalytic domain of p97. Mapping of the binding site using a photoaffinity conjugate points to a cleft at the interface of the N-terminal and the D1 ATPase domains. We have therefore discovered two new compounds that bind to the regulatory domain of p97 and modulate specific p97 cellular functions. Using these compounds, we have revealed a role for p97 in the regulation of mitotic spindle orientation in HeLa cells.
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Affiliation(s)
- Ainoa Figuerola-Conchas
- Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva 4, Switzerland
- National Centre of Competence in Research (NCCR) in Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Jacques Saarbach
- Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva 4, Switzerland
- National Centre of Competence in Research (NCCR) in Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Jean-Pierre Daguer
- National Centre of Competence in Research (NCCR) in Chemical Biology, University of Geneva, Geneva, Switzerland
- Department of Organic Chemistry, University of Geneva, 1211 Geneva 4, Switzerland
| | - Adeline Cieren
- Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva 4, Switzerland
- National Centre of Competence in Research (NCCR) in Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Sofia Barluenga
- National Centre of Competence in Research (NCCR) in Chemical Biology, University of Geneva, Geneva, Switzerland
- Department of Organic Chemistry, University of Geneva, 1211 Geneva 4, Switzerland
| | - Nicolas Winssinger
- National Centre of Competence in Research (NCCR) in Chemical Biology, University of Geneva, Geneva, Switzerland
- Department of Organic Chemistry, University of Geneva, 1211 Geneva 4, Switzerland
| | - Monica Gotta
- Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva 4, Switzerland
- National Centre of Competence in Research (NCCR) in Chemical Biology, University of Geneva, Geneva, Switzerland
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69
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Lehrbach NJ, Breen PC, Ruvkun G. Protein Sequence Editing of SKN-1A/Nrf1 by Peptide:N-Glycanase Controls Proteasome Gene Expression. Cell 2020; 177:737-750.e15. [PMID: 31002798 DOI: 10.1016/j.cell.2019.03.035] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 12/14/2018] [Accepted: 03/15/2019] [Indexed: 12/20/2022]
Abstract
The proteasome mediates selective protein degradation and is dynamically regulated in response to proteotoxic challenges. SKN-1A/Nrf1, an endoplasmic reticulum (ER)-associated transcription factor that undergoes N-linked glycosylation, serves as a sensor of proteasome dysfunction and triggers compensatory upregulation of proteasome subunit genes. Here, we show that the PNG-1/NGLY1 peptide:N-glycanase edits the sequence of SKN-1A protein by converting particular N-glycosylated asparagine residues to aspartic acid. Genetically introducing aspartates at these N-glycosylation sites bypasses the requirement for PNG-1/NGLY1, showing that protein sequence editing rather than deglycosylation is key to SKN-1A function. This pathway is required to maintain sufficient proteasome expression and activity, and SKN-1A hyperactivation confers resistance to the proteotoxicity of human amyloid beta peptide. Deglycosylation-dependent protein sequence editing explains how ER-associated and cytosolic isoforms of SKN-1 perform distinct cytoprotective functions corresponding to those of mammalian Nrf1 and Nrf2. Thus, we uncover an unexpected mechanism by which N-linked glycosylation regulates protein function and proteostasis.
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Affiliation(s)
- Nicolas J Lehrbach
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Peter C Breen
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
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Antoniou N, Lagopati N, Balourdas DI, Nikolaou M, Papalampros A, Vasileiou PVS, Myrianthopoulos V, Kotsinas A, Shiloh Y, Liontos M, Gorgoulis VG. The Role of E3, E4 Ubiquitin Ligase (UBE4B) in Human Pathologies. Cancers (Basel) 2019; 12:cancers12010062. [PMID: 31878315 PMCID: PMC7017255 DOI: 10.3390/cancers12010062] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/21/2019] [Accepted: 11/23/2019] [Indexed: 12/18/2022] Open
Abstract
The genome is exposed daily to many deleterious factors. Ubiquitination is a mechanism that regulates several crucial cellular functions, allowing cells to react upon various stimuli in order to preserve their homeostasis. Ubiquitin ligases act as specific regulators and actively participate among others in the DNA damage response (DDR) network. UBE4B is a newly identified member of E3 ubiquitin ligases that appears to be overexpressed in several human neoplasms. The aim of this review is to provide insights into the role of UBE4B ubiquitin ligase in DDR and its association with p53 expression, shedding light particularly on the molecular mechanisms of carcinogenesis.
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Affiliation(s)
- Nikolaos Antoniou
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, National Kapodistrian University of Athens, 75 Mikras Asias Str., Goudi, GR-11527 Athens, Greece; (N.A.); (N.L.); (P.V.S.V.); (M.L.)
| | - Nefeli Lagopati
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, National Kapodistrian University of Athens, 75 Mikras Asias Str., Goudi, GR-11527 Athens, Greece; (N.A.); (N.L.); (P.V.S.V.); (M.L.)
| | - Dimitrios Ilias Balourdas
- Department of Pharmacy, National Kapodistrian University of Athens, Panepistimiopolis Zografou, GR-15771 Athens, Greece; (D.I.B.); (V.M.)
| | - Michail Nikolaou
- General Maternal Hospital of Athens “Elena Venizelou”, GR-11521 Athens, Greece;
| | - Alexandros Papalampros
- First Department of Surgery, Laikon Teaching Hospital, School of Medicine, National Kapodistrian University of Athens, 75 Mikras Asias Str., Goudi, GR-11527 Athens, Greece;
| | - Panagiotis V. S. Vasileiou
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, National Kapodistrian University of Athens, 75 Mikras Asias Str., Goudi, GR-11527 Athens, Greece; (N.A.); (N.L.); (P.V.S.V.); (M.L.)
| | - Vassilios Myrianthopoulos
- Department of Pharmacy, National Kapodistrian University of Athens, Panepistimiopolis Zografou, GR-15771 Athens, Greece; (D.I.B.); (V.M.)
| | - Athanassios Kotsinas
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, National Kapodistrian University of Athens, 75 Mikras Asias Str., Goudi, GR-11527 Athens, Greece; (N.A.); (N.L.); (P.V.S.V.); (M.L.)
- Correspondence: (A.K.); (V.G.G.); Tel.: +30-210-746-2350 (V.G.G.)
| | - Yosef Shiloh
- The David and Inez Myers Laboratory for Cancer Research, Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel;
| | - Michalis Liontos
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, National Kapodistrian University of Athens, 75 Mikras Asias Str., Goudi, GR-11527 Athens, Greece; (N.A.); (N.L.); (P.V.S.V.); (M.L.)
- Oncology Unit, Department of Clinical Therapeutics, Medical School, National and Kapodistrian University of Athens, Alexandra Hospital, GR-11528 Athens, Greece
| | - Vassilis G. Gorgoulis
- Molecular Carcinogenesis Group, Department of Histology and Embryology, School of Medicine, National Kapodistrian University of Athens, 75 Mikras Asias Str., Goudi, GR-11527 Athens, Greece; (N.A.); (N.L.); (P.V.S.V.); (M.L.)
- Biomedical Research Foundation of the Academy of Athens, GR-11527 Athens, Greece
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M20 4GJ, UK
- Correspondence: (A.K.); (V.G.G.); Tel.: +30-210-746-2350 (V.G.G.)
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71
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Matsumoto S, Nakatsukasa K, Kakuta C, Tamura Y, Esaki M, Endo T. Msp1 Clears Mistargeted Proteins by Facilitating Their Transfer from Mitochondria to the ER. Mol Cell 2019; 76:191-205.e10. [DOI: 10.1016/j.molcel.2019.07.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 06/03/2019] [Accepted: 07/08/2019] [Indexed: 12/18/2022]
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72
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Haakonsen DL, Rape M. Branching Out: Improved Signaling by Heterotypic Ubiquitin Chains. Trends Cell Biol 2019; 29:704-716. [PMID: 31300189 DOI: 10.1016/j.tcb.2019.06.003] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/06/2019] [Accepted: 06/11/2019] [Indexed: 02/08/2023]
Abstract
Ubiquitin chains of distinct topologies control the stability, interactions, or localization of many proteins in eukaryotic cells, and thus play an essential role in cellular information transfer. It has recently been found that ubiquitin chains can be combined to produce branched conjugates that are characterized by the presence of at least two linkages within the same polymer. Akin to their homotypic counterparts, branched chains elicit a wide array of biological outputs, further expanding the versatility, specificity, and efficiency of ubiquitin-dependent signaling. This review discusses emerging understanding of the synthesis and function of branched ubiquitin chains.
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Affiliation(s)
- Diane L Haakonsen
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA.
| | - Michael Rape
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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73
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Tomita T, Matouschek A. Substrate selection by the proteasome through initiation regions. Protein Sci 2019; 28:1222-1232. [PMID: 31074920 DOI: 10.1002/pro.3642] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/03/2019] [Accepted: 05/06/2019] [Indexed: 01/04/2023]
Abstract
Proteins in the cell have to be eliminated once their function is no longer desired or they become damaged. Most regulated protein degradation is achieved by a large enzymatic complex called the proteasome. Many proteasome substrates are targeted for degradation by the covalent attachment of ubiquitin molecules. Ubiquitinated proteins can be bound by the proteasome, but for proteolysis to occur the proteasome needs to find a disordered tail somewhere in the target at which it initiates degradation. The initiation step contributes to the specificity of proteasomal degradation. Here, we review how the proteasome selects initiation sites within its substrates and discuss how the initiation step affects physiological processes.
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Affiliation(s)
- Takuya Tomita
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, 78712
| | - Andreas Matouschek
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, 78712
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74
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Chassin H, Müller M, Tigges M, Scheller L, Lang M, Fussenegger M. A modular degron library for synthetic circuits in mammalian cells. Nat Commun 2019; 10:2013. [PMID: 31043592 PMCID: PMC6494899 DOI: 10.1038/s41467-019-09974-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 04/04/2019] [Indexed: 01/26/2023] Open
Abstract
Tight control over protein degradation is a fundamental requirement for cells to respond rapidly to various stimuli and adapt to a fluctuating environment. Here we develop a versatile, easy-to-handle library of destabilizing tags (degrons) for the precise regulation of protein expression profiles in mammalian cells by modulating target protein half-lives in a predictable manner. Using the well-established tetracycline gene-regulation system as a model, we show that the dynamics of protein expression can be tuned by fusing appropriate degron tags to gene regulators. Next, we apply this degron library to tune a synthetic pulse-generating circuit in mammalian cells. With this toolbox we establish a set of pulse generators with tailored pulse lengths and magnitudes of protein expression. This methodology will prove useful in the functional roles of essential proteins, fine-tuning of gene-expression systems, and enabling a higher complexity in the design of synthetic biological systems in mammalian cells.
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Affiliation(s)
- Hélène Chassin
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Marius Müller
- Cilag AG, Hochstrasse 201, CH-8200, Schaffhausen, Switzerland
| | - Marcel Tigges
- Cilag AG, Hochstrasse 201, CH-8200, Schaffhausen, Switzerland
| | - Leo Scheller
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Moritz Lang
- Institute of Science and Technology Austria, A-3400, Klosterneuburg, Austria
| | - Martin Fussenegger
- Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, CH-4058, Basel, Switzerland.
- Faculty of Science, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland.
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75
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Upadhyay A. Structure of proteins: Evolution with unsolved mysteries. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 149:160-172. [PMID: 31014967 DOI: 10.1016/j.pbiomolbio.2019.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 04/16/2019] [Accepted: 04/19/2019] [Indexed: 02/07/2023]
Abstract
Evolution of macromolecules could be considered as a milestone in the history of life. Nucleic acids are the long stretches of nucleotides that contain all the possible codes and information of life. On the other hand, proteins are their actual translated outcomes, or reflections of modifications in their structure that have occurred at a slow, but steady rate over a very long period of evolution. Over the years of research, biophysicists, biochemists, molecular and structural biologists have unfurled several layers of the structural convolutions in these chemical molecules; however evolutionists look over their structures through a different prism, which may or may not coincide with others. There remains a need to outline several well-known, but less discussed features of protein structures, like intrinsically disordered states, degron signals and different types of ubiquitin chains providing degradation signals, which help the cellular proteolytic machinery to identify and target the proteins towards degradation pathways. There are several important factors, which are critical for folding of proteins into their native three-dimensional conformations by the cytoplasmic chaperones; but in real time how the chaperones fold the newly synthesized polypeptide sequences into a particular three-dimensional shape within a fraction of second is still a mystery for biologists as well as mathematicians. Multiple similar unsolved or unaddressed questions need to be addressed in detail so that future line of research can dig deeper into the finer details of these structures of the proteins.
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Affiliation(s)
- Arun Upadhyay
- Department of Biochemistry, Central University of Rajasthan, Ajmer, 305817, India.
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76
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Lehrbach NJ, Ruvkun G. Endoplasmic reticulum-associated SKN-1A/Nrf1 mediates a cytoplasmic unfolded protein response and promotes longevity. eLife 2019; 8:44425. [PMID: 30973820 PMCID: PMC6459674 DOI: 10.7554/elife.44425] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/29/2019] [Indexed: 01/21/2023] Open
Abstract
Unfolded protein responses (UPRs) safeguard cellular function during proteotoxic stress and aging. In a previous paper (Lehrbach and Ruvkun, 2016) we showed that the ER-associated SKN-1A/Nrf1 transcription factor activates proteasome subunit expression in response to proteasome dysfunction, but it was not established whether SKN-1A/Nrf1 adjusts proteasome capacity in response to other proteotoxic insults. Here, we reveal that misfolded endogenous proteins and the human amyloid beta peptide trigger activation of proteasome subunit expression by SKN-1A/Nrf1. SKN-1A activation is protective against age-dependent defects caused by accumulation of misfolded and aggregation-prone proteins. In a C. elegans Alzheimer’s disease model, SKN-1A/Nrf1 slows accumulation of the amyloid beta peptide and delays adult-onset cellular dysfunction. Our results indicate that SKN-1A surveys cellular protein folding and adjusts proteasome capacity to meet the demands of protein quality control pathways, revealing a new arm of the cytosolic UPR. This regulatory axis is critical for healthy aging and may be a target for therapeutic modulation of human aging and age-related disease.
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Affiliation(s)
- Nicolas J Lehrbach
- Department of Molecular Biology, Massachusetts General Hospital, Boston, United States.,Department of Genetics, Harvard Medical School, Boston, United States
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, United States.,Department of Genetics, Harvard Medical School, Boston, United States
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77
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Kats I, Khmelinskii A, Kschonsak M, Huber F, Knieß RA, Bartosik A, Knop M. Mapping Degradation Signals and Pathways in a Eukaryotic N-terminome. Mol Cell 2019; 70:488-501.e5. [PMID: 29727619 DOI: 10.1016/j.molcel.2018.03.033] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/26/2018] [Accepted: 03/27/2018] [Indexed: 01/01/2023]
Abstract
Most eukaryotic proteins are N-terminally acetylated. This modification can be recognized as a signal for selective protein degradation (degron) by the N-end rule pathways. However, the prevalence and specificity of such degrons in the proteome are unclear. Here, by systematically examining how protein turnover is affected by N-terminal sequences, we perform a comprehensive survey of degrons in the yeast N-terminome. We find that approximately 26% of nascent protein N termini encode cryptic degrons. These degrons exhibit high hydrophobicity and are frequently recognized by the E3 ubiquitin ligase Doa10, suggesting a role in protein quality control. In contrast, N-terminal acetylation rarely functions as a degron. Surprisingly, we identify two pathways where N-terminal acetylation has the opposite function and blocks protein degradation through the E3 ubiquitin ligase Ubr1. Our analysis highlights the complexity of N-terminal degrons and argues that hydrophobicity, not N-terminal acetylation, is the predominant feature of N-terminal degrons in nascent proteins.
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Affiliation(s)
- Ilia Kats
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Anton Khmelinskii
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Marc Kschonsak
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Florian Huber
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Robert A Knieß
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Anna Bartosik
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Michael Knop
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany; Deutsches Krebsforschungszentrum (DKFZ), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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78
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The Roles of Ubiquitin-Binding Protein Shuttles in the Degradative Fate of Ubiquitinated Proteins in the Ubiquitin-Proteasome System and Autophagy. Cells 2019; 8:cells8010040. [PMID: 30634694 PMCID: PMC6357184 DOI: 10.3390/cells8010040] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 12/24/2018] [Accepted: 01/03/2019] [Indexed: 12/15/2022] Open
Abstract
The ubiquitin-proteasome system (UPS) and autophagy are the two major intracellular protein quality control (PQC) pathways that are responsible for cellular proteostasis (homeostasis of the proteome) by ensuring the timely degradation of misfolded, damaged, and unwanted proteins. Ubiquitination serves as the degradation signal in both these systems, but substrates are precisely targeted to one or the other pathway. Determining how and when cells target specific proteins to these two alternative PQC pathways and control the crosstalk between them are topics of considerable interest. The ubiquitin (Ub) recognition code based on the type of Ub-linked chains on substrate proteins was believed to play a pivotal role in this process, but an increasing body of evidence indicates that the PQC pathway choice is also made based on other criteria. These include the oligomeric state of the Ub-binding protein shuttles, their conformation, protein modifications, and the presence of motifs that interact with ATG8/LC3/GABARAP (autophagy-related protein 8/microtubule-associated protein 1A/1B-light chain 3/GABA type A receptor-associated protein) protein family members. In this review, we summarize the current knowledge regarding the Ub recognition code that is bound by Ub-binding proteasomal and autophagic receptors. We also discuss how cells can modify substrate fate by modulating the structure, conformation, and physical properties of these receptors to affect their shuttling between both degradation pathways.
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79
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Fletcher AJ, Vaysburd M, Maslen S, Zeng J, Skehel JM, Towers GJ, James LC. Trivalent RING Assembly on Retroviral Capsids Activates TRIM5 Ubiquitination and Innate Immune Signaling. Cell Host Microbe 2018; 24:761-775.e6. [PMID: 30503508 PMCID: PMC6299210 DOI: 10.1016/j.chom.2018.10.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/31/2018] [Accepted: 10/16/2018] [Indexed: 01/14/2023]
Abstract
TRIM5 is a RING domain E3 ubiquitin ligase with potent antiretroviral function. TRIM5 assembles into a hexagonal lattice on retroviral capsids, causing envelopment of the infectious core. Concomitantly, TRIM5 initiates innate immune signaling and orchestrates disassembly of the viral particle, yet how these antiviral responses are regulated by capsid recognition is unclear. We show that hexagonal assembly triggers N-terminal polyubiquitination of TRIM5 that collectively drives antiviral responses. In uninfected cells, N-terminal monoubiquitination triggers non-productive TRIM5 turnover. Upon TRIM5 assembly on virus, a trivalent RING arrangement allows elongation of N-terminally anchored K63-linked ubiquitin chains (N-K63-Ub). N-K63-Ub drives TRIM5 innate immune stimulation and proteasomal degradation. Inducing ubiquitination before TRIM5 assembly triggers premature degradation and ablates antiviral restriction. Conversely, driving N-K63 ubiquitination after TRIM5 assembly enhances innate immune signaling. Thus, the hexagonal geometry of TRIM5's antiviral lattice converts a capsid-binding protein into a multifunctional antiviral platform.
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Affiliation(s)
- Adam J Fletcher
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Marina Vaysburd
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jingwei Zeng
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - J Mark Skehel
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Greg J Towers
- Infection and Immunity, University College London, Cruciform Building, 90 Gower Street, London WC1E 6BT, UK
| | - Leo C James
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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80
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Chowdhury A, Ogura T, Esaki M. Two Cdc48 cofactors Ubp3 and Ubx2 regulate mitochondrial morphology and protein turnover. J Biochem 2018; 164:349-358. [PMID: 29924334 DOI: 10.1093/jb/mvy057] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/13/2018] [Indexed: 12/22/2022] Open
Abstract
Mitochondria continuously undergo coordinated fusion and fission during vegetative growth to keep their homogeneity and to remove damaged components. A cytosolic AAA ATPase, Cdc48, is implicated in the mitochondrial fusion event and turnover of a fusion-responsible GTPase in the mitochondrial outer membrane, Fzo1, suggesting a possible linkage of mitochondrial fusion and Fzo1 turnover. Here, we identified two Cdc48 cofactor proteins, Ubp3 and Ubx2, involving mitochondria regulation. In the absence of UBP3, mitochondrial fragmentation and aggregation were observed. The turnover of Fzo1 was not affected in Δubp3, but instead a deubiquitylase Ubp12 that removes fusion-required polyubiquitin chains from Fzo1 was stabilized. Thus, excess amount of Ubp12 may lead to mitochondrial fragmentation by removal of fusion-competent ubiquitylated Fzo1. In contrast, deletion of UBX2 perturbed disassembly of Fzo1 oligomers and their degradation without alteration of mitochondrial morphology. The UBX2 deletion led to destabilization of Ubp2 that negatively regulates Fzo1 turnover by removing degradation-signalling polyubiquitin chains, suggesting that Ubx2 would directly facilitate Fzo1 degradation. These results indicated that two different Cdc48-cofactor complexes independently regulate mitochondrial fusion and Fzo1 turnover.
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Affiliation(s)
- Abhijit Chowdhury
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto, Japan
| | - Teru Ogura
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Honcho 4-1-8, Kawaguchi-shi, Saitama, Japan
| | - Masatoshi Esaki
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Honcho 4-1-8, Kawaguchi-shi, Saitama, Japan
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81
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Wang Z, Wu C, Aslanian A, Yates JR, Hunter T. Defective RNA polymerase III is negatively regulated by the SUMO-Ubiquitin-Cdc48 pathway. eLife 2018; 7:35447. [PMID: 30192228 PMCID: PMC6128692 DOI: 10.7554/elife.35447] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 08/21/2018] [Indexed: 12/26/2022] Open
Abstract
Transcription by RNA polymerase III (Pol III) is an essential cellular process, and mutations in Pol III can cause neurodegenerative disease in humans. However, in contrast to Pol II transcription, which has been extensively studied, the knowledge of how Pol III is regulated is very limited. We report here that in budding yeast, Saccharomyces cerevisiae, Pol III is negatively regulated by the Small Ubiquitin-like MOdifier (SUMO), an essential post-translational modification pathway. Besides sumoylation, Pol III is also targeted by ubiquitylation and the Cdc48/p97 segregase; these three processes likely act in a sequential manner and eventually lead to proteasomal degradation of Pol III subunits, thereby repressing Pol III transcription. This study not only uncovered a regulatory mechanism for Pol III, but also suggests that the SUMO and ubiquitin modification pathways and the Cdc48/p97 segregase can be potential therapeutic targets for Pol III-related human diseases.
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Affiliation(s)
- Zheng Wang
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, United States
| | - Catherine Wu
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, United States
| | - Aaron Aslanian
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, United States.,The Scripps Research Institute, La Jolla, United States
| | - John R Yates
- The Scripps Research Institute, La Jolla, United States
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, United States
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82
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Parisi E, Yahya G, Flores A, Aldea M. Cdc48/p97 segregase is modulated by cyclin-dependent kinase to determine cyclin fate during G1 progression. EMBO J 2018; 37:embj.201798724. [PMID: 29950310 DOI: 10.15252/embj.201798724] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 05/14/2018] [Accepted: 06/12/2018] [Indexed: 01/26/2023] Open
Abstract
Cells sense myriad signals during G1, and a rapid response to prevent cell cycle entry is of crucial importance for proper development and adaptation. Cln3, the most upstream G1 cyclin in budding yeast, is an extremely short-lived protein subject to ubiquitination and proteasomal degradation. On the other hand, nuclear accumulation of Cln3 depends on chaperones that are also important for its degradation. However, how these processes are intertwined to control G1-cyclin fate is not well understood. Here, we show that Cln3 undergoes a challenging ubiquitination step required for both degradation and full activation. Segregase Cdc48/p97 prevents degradation of ubiquitinated Cln3, and concurrently stimulates its ER release and nuclear accumulation to trigger Start. Cdc48/p97 phosphorylation at conserved Cdk-target sites is important for recruitment of specific cofactors and, in both yeast and mammalian cells, to attain proper G1-cyclin levels and activity. Cdk-dependent modulation of Cdc48 would subjugate G1 cyclins to fast and reversible state switching, thus arresting cells promptly in G1 at developmental or environmental checkpoints, but also resuming G1 progression immediately after proliferative signals reappear.
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Affiliation(s)
- Eva Parisi
- Molecular Biology Institute of Barcelona IBMB-CSIC, Barcelona, Catalonia, Spain
| | - Galal Yahya
- Molecular Biology Institute of Barcelona IBMB-CSIC, Barcelona, Catalonia, Spain.,Department of Microbiology and Immunology, School of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Alba Flores
- Molecular Biology Institute of Barcelona IBMB-CSIC, Barcelona, Catalonia, Spain
| | - Martí Aldea
- Molecular Biology Institute of Barcelona IBMB-CSIC, Barcelona, Catalonia, Spain .,Departament de Ciències Bàsiques, Universitat Internacional de Catalunya, Barcelona, Catalonia, Spain
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83
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Abstract
As the endpoint for the ubiquitin-proteasome system, the 26S proteasome is the principal proteolytic machine responsible for regulated protein degradation in eukaryotic cells. The proteasome's cellular functions range from general protein homeostasis and stress response to the control of vital processes such as cell division and signal transduction. To reliably process all the proteins presented to it in the complex cellular environment, the proteasome must combine high promiscuity with exceptional substrate selectivity. Recent structural and biochemical studies have shed new light on the many steps involved in proteasomal substrate processing, including recognition, deubiquitination, and ATP-driven translocation and unfolding. In addition, these studies revealed a complex conformational landscape that ensures proper substrate selection before the proteasome commits to processive degradation. These advances in our understanding of the proteasome's intricate machinery set the stage for future studies on how the proteasome functions as a major regulator of the eukaryotic proteome.
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Affiliation(s)
- Jared A M Bard
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA;
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, California 94720, USA
| | - Ellen A Goodall
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA;
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, California 94720, USA
| | - Eric R Greene
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA;
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, California 94720, USA
| | - Erik Jonsson
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA;
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, California 94720, USA
| | - Ken C Dong
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA;
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, California 94720, USA
| | - Andreas Martin
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA;
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, California 94720, USA
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84
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Habtemichael EN, Li DT, Alcázar-Román A, Westergaard XO, Li M, Petersen MC, Li H, DeVries SG, Li E, Julca-Zevallos O, Wolenski JS, Bogan JS. Usp25m protease regulates ubiquitin-like processing of TUG proteins to control GLUT4 glucose transporter translocation in adipocytes. J Biol Chem 2018; 293:10466-10486. [PMID: 29773651 DOI: 10.1074/jbc.ra118.003021] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/09/2018] [Indexed: 12/14/2022] Open
Abstract
Insulin stimulates the exocytic translocation of specialized vesicles in adipocytes, which inserts GLUT4 glucose transporters into the plasma membrane to enhance glucose uptake. Previous results support a model in which TUG (Tether containing a UBX domain for GLUT4) proteins trap these GLUT4 storage vesicles at the Golgi matrix and in which insulin triggers endoproteolytic cleavage of TUG to translocate GLUT4. Here, we identify the muscle splice form of Usp25 (Usp25m) as a protease required for insulin-stimulated TUG cleavage and GLUT4 translocation in adipocytes. Usp25m is expressed in adipocytes, binds TUG and GLUT4, dissociates from TUG-bound vesicles after insulin addition, and colocalizes with TUG and insulin-responsive cargoes in unstimulated cells. Previous results show that TUG proteolysis generates the ubiquitin-like protein, TUGUL (for TUGubiquitin-like). We now show that TUGUL modifies the kinesin motor protein, KIF5B, and that TUG proteolysis is required to load GLUT4 onto these motors. Insulin stimulates TUG proteolytic processing independently of phosphatidylinositol 3-kinase. In nonadipocytes, TUG cleavage can be reconstituted by transfection of Usp25m, but not the related Usp25a isoform, together with other proteins present on GLUT4 vesicles. In rodents with diet-induced insulin resistance, TUG proteolysis and Usp25m protein abundance are reduced in adipose tissue. These effects occur soon after dietary manipulation, prior to the attenuation of insulin signaling to Akt. Together with previous data, these results support a model whereby insulin acts through Usp25m to mediate TUG cleavage, which liberates GLUT4 storage vesicles from the Golgi matrix and activates their microtubule-based movement to the plasma membrane. This TUG proteolytic pathway for insulin action is independent of Akt and is impaired by nutritional excess.
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Affiliation(s)
| | - Don T Li
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and.,the Departments of Cell Biology and
| | - Abel Alcázar-Román
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and
| | - Xavier O Westergaard
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and
| | - Muyi Li
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and
| | - Max C Petersen
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and.,Cellular and Molecular Physiology, Yale University School of Medicine
| | - Hanbing Li
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and.,the Institute of Pharmacology, Department of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China
| | - Stephen G DeVries
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and
| | - Eric Li
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and
| | - Omar Julca-Zevallos
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and.,the Departments of Cell Biology and
| | - Joseph S Wolenski
- the Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, and
| | - Jonathan S Bogan
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine and .,the Departments of Cell Biology and
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85
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Albrecht D, Hürlimann HC, Ceschin J, Saint-Marc C, Pinson B, Daignan-Fornier B. Multiple chemo-genetic interactions between a toxic metabolite and the ubiquitin pathway in yeast. Curr Genet 2018; 64:1275-1286. [PMID: 29721631 DOI: 10.1007/s00294-018-0843-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/17/2018] [Accepted: 04/26/2018] [Indexed: 12/21/2022]
Abstract
AICAR is the precursor of ZMP, a metabolite with antiproliferative properties in yeast and human. We aim at understanding how AICAR (and its active form ZMP) affects essential cellular processes. In this work, we found that ZMP accumulation is synthetic lethal with a hypomorphic allele of the ubiquitin-activating enzyme Uba1. A search for gene-dosage suppressors revealed that ubiquitin overexpression was sufficient to restore growth of the uba1 mutant upon AICAR treatment, suggesting that the ubiquitin pool is critical for cells to cope with AICAR. Accordingly, two mutants with constitutive low ubiquitin, ubp6 and doa1, were highly sensitive to AICAR, a phenotype that could be suppressed by ubiquitin overexpression. We established, by genetic means, that these new AICAR-sensitive mutants act in a different pathway from the rad6/bre1 mutants which were previously reported as sensitive to AICAR (Albrecht et al., Genetics 204:1447-1460, 2016). Two ubiquitin-conjugating enzymes (Ubc4 and Cdc34) and a ubiquitin ligase (Cdc4) were found to contribute to the ability of cells to cope with ZMP. This study illustrates the complexity of chemo-genetic interactions and shows how genetic analyses allow deciphering the implicated pathways, the individual gene effects, and their combined phenotypic contribution. Based on additivity and suppression patterns, we conclude that AICAR treatment shows synthetic interactions with distinct branches of the yeast ubiquitin pathway.
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Affiliation(s)
- Delphine Albrecht
- Université de Bordeaux, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
- Centre National de la Recherche Scientifique, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
| | - Hans C Hürlimann
- Université de Bordeaux, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
- Centre National de la Recherche Scientifique, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
- Institut für Biologie, Martin-Luther Universität, Universität Halle-Wittenberg, Weinbergweg 10, 06120, Halle (Saale), Germany
| | - Johanna Ceschin
- Université de Bordeaux, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
- Centre National de la Recherche Scientifique, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
| | - Christelle Saint-Marc
- Université de Bordeaux, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
- Centre National de la Recherche Scientifique, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
| | - Benoît Pinson
- Université de Bordeaux, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
- Centre National de la Recherche Scientifique, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
| | - Bertrand Daignan-Fornier
- Université de Bordeaux, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France.
- Centre National de la Recherche Scientifique, IBGC UMR 5095, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France.
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, 1 rue C. Saint-Saëns CS 61390, 33077, Bordeaux, France.
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86
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Wu X, Rapoport TA. Mechanistic insights into ER-associated protein degradation. Curr Opin Cell Biol 2018; 53:22-28. [PMID: 29719269 DOI: 10.1016/j.ceb.2018.04.004] [Citation(s) in RCA: 239] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 04/11/2018] [Accepted: 04/11/2018] [Indexed: 12/16/2022]
Abstract
Misfolded proteins of the endoplasmic reticulum (ER) are discarded by a conserved process, called ER-associated protein degradation (ERAD). ERAD substrates are retro-translocated into the cytosol, polyubiquitinated, extracted from the ER membrane, and ultimately degraded by the proteasome. Recent in vitro experiments with purified components have given insight into the mechanism of ERAD. ERAD substrates with misfolded luminal or intramembrane domains are moved across the ER membrane through a channel formed by the multispanning ubiquitin ligase Hrd1. Following polyubiquitination, substrates are extracted from the membrane by the Cdc48/p97 ATPase complex and transferred to the proteasome. We discuss the molecular mechanism of these processes and point out remaining open questions.
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Affiliation(s)
- Xudong Wu
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, United States
| | - Tom A Rapoport
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, United States.
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87
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Baranes-Bachar K, Levy-Barda A, Oehler J, Reid DA, Soria-Bretones I, Voss TC, Chung D, Park Y, Liu C, Yoon JB, Li W, Dellaire G, Misteli T, Huertas P, Rothenberg E, Ramadan K, Ziv Y, Shiloh Y. The Ubiquitin E3/E4 Ligase UBE4A Adjusts Protein Ubiquitylation and Accumulation at Sites of DNA Damage, Facilitating Double-Strand Break Repair. Mol Cell 2018; 69:866-878.e7. [PMID: 29499138 PMCID: PMC6265044 DOI: 10.1016/j.molcel.2018.02.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 12/12/2017] [Accepted: 01/31/2018] [Indexed: 11/18/2022]
Abstract
Double-strand breaks (DSBs) are critical DNA lesions that robustly activate the elaborate DNA damage response (DDR) network. We identified a critical player in DDR fine-tuning: the E3/E4 ubiquitin ligase UBE4A. UBE4A's recruitment to sites of DNA damage is dependent on primary E3 ligases in the DDR and promotes enhancement and sustainment of K48- and K63-linked ubiquitin chains at these sites. This step is required for timely recruitment of the RAP80 and BRCA1 proteins and proper organization of RAP80- and BRCA1-associated protein complexes at DSB sites. This pathway is essential for optimal end resection at DSBs, and its abrogation leads to upregulation of the highly mutagenic alternative end-joining repair at the expense of error-free homologous recombination repair. Our data uncover a critical regulatory level in the DSB response and underscore the importance of fine-tuning the complex DDR network for accurate and balanced execution of DSB repair.
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Affiliation(s)
- Keren Baranes-Bachar
- The David and Inez Myers Laboratory for Cancer Research, Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Adva Levy-Barda
- The David and Inez Myers Laboratory for Cancer Research, Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Judith Oehler
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Dylan A Reid
- Perlmutter NYU Cancer Center and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Isabel Soria-Bretones
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER) and Department of Genetics, University of Sevilla, Sevilla, Spain
| | - Ty C Voss
- National Cancer Institute, NIH, Bethesda, MD, USA
| | - Dudley Chung
- Departments of Pathology and Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Yoon Park
- Department of Biochemistry and Protein Network Research Center, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul, Korea
| | - Chao Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jong-Bok Yoon
- Department of Biochemistry and Protein Network Research Center, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul, Korea
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Graham Dellaire
- Departments of Pathology and Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Tom Misteli
- National Cancer Institute, NIH, Bethesda, MD, USA
| | - Pablo Huertas
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER) and Department of Genetics, University of Sevilla, Sevilla, Spain
| | - Eli Rothenberg
- Perlmutter NYU Cancer Center and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Kristijan Ramadan
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Yael Ziv
- The David and Inez Myers Laboratory for Cancer Research, Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yosef Shiloh
- The David and Inez Myers Laboratory for Cancer Research, Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
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88
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Tsuchiya H, Burana D, Ohtake F, Arai N, Kaiho A, Komada M, Tanaka K, Saeki Y. Ub-ProT reveals global length and composition of protein ubiquitylation in cells. Nat Commun 2018; 9:524. [PMID: 29410401 PMCID: PMC5802829 DOI: 10.1038/s41467-018-02869-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 01/02/2018] [Indexed: 01/09/2023] Open
Abstract
Protein ubiquitylation regulates diverse cellular processes via distinct ubiquitin chains that differ by linkage type and length. However, a comprehensive method for measuring these properties has not been developed. Here we describe a method for assessing the length of substrate-attached polyubiquitin chains, "ubiquitin chain protection from trypsinization (Ub-ProT)." Using Ub-ProT, we found that most ubiquitylated substrates in yeast-soluble lysate are attached to chains of up to seven ubiquitin molecules. Inactivation of the ubiquitin-selective chaperone Cdc48 caused a dramatic increase in chain lengths on substrate proteins, suggesting that Cdc48 complex terminates chain elongation by substrate extraction. In mammalian cells, we found that ligand-activated epidermal growth factor receptor (EGFR) is rapidly modified with K63-linked tetra- to hexa-ubiquitin chains following EGF treatment in human cells. Thus, the Ub-ProT method can contribute to our understanding of mechanisms regulating physiological ubiquitin chain lengths and composition.
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Affiliation(s)
- Hikaru Tsuchiya
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Daocharad Burana
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.,Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259-B16 Nagatsuta, Midori, Yokohama, 226-8501, Japan
| | - Fumiaki Ohtake
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Naoko Arai
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Ai Kaiho
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Masayuki Komada
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259-B16 Nagatsuta, Midori, Yokohama, 226-8501, Japan
| | - Keiji Tanaka
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.
| | - Yasushi Saeki
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.
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89
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Hellerschmied D, Roessler M, Lehner A, Gazda L, Stejskal K, Imre R, Mechtler K, Dammermann A, Clausen T. UFD-2 is an adaptor-assisted E3 ligase targeting unfolded proteins. Nat Commun 2018; 9:484. [PMID: 29396393 PMCID: PMC5797217 DOI: 10.1038/s41467-018-02924-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 01/09/2018] [Indexed: 11/09/2022] Open
Abstract
Muscle development requires the coordinated activities of specific protein folding and degradation factors. UFD-2, a U-box ubiquitin ligase, has been reported to play a central role in this orchestra regulating the myosin chaperone UNC-45. Here, we apply an integrative in vitro and in vivo approach to delineate the substrate-targeting mechanism of UFD-2 and elucidate its distinct mechanistic features as an E3/E4 enzyme. Using Caenorhabditis elegans as model system, we demonstrate that UFD-2 is not regulating the protein levels of UNC-45 in muscle cells, but rather shows the characteristic properties of a bona fide E3 ligase involved in protein quality control. Our data demonstrate that UFD-2 preferentially targets unfolded protein segments. Moreover, the UNC-45 chaperone can serve as an adaptor protein of UFD-2 to poly-ubiquitinate unfolded myosin, pointing to a possible role of the UFD-2/UNC-45 pair in maintaining proteostasis in muscle cells.
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Affiliation(s)
- Doris Hellerschmied
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030, Vienna, Austria.,Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, 06511, USA
| | - Max Roessler
- Max F. Perutz Laboratories (MFPL), University of Vienna, Doktor-Bohr-Gasse 9, 1030, Vienna, Austria
| | - Anita Lehner
- Vienna Biocenter Core Facilities, Doktor-Bohr-Gasse 3, 1030, Vienna, Austria
| | - Linn Gazda
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030, Vienna, Austria
| | - Karel Stejskal
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030, Vienna, Austria
| | - Richard Imre
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030, Vienna, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030, Vienna, Austria
| | - Alexander Dammermann
- Max F. Perutz Laboratories (MFPL), University of Vienna, Doktor-Bohr-Gasse 9, 1030, Vienna, Austria.
| | - Tim Clausen
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030, Vienna, Austria. .,Medical University of Vienna, Vienna BioCenter (VBC), 1030, Vienna, Austria.
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90
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Trujillo M. News from the PUB: plant U-box type E3 ubiquitin ligases. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:371-384. [PMID: 29237060 DOI: 10.1093/jxb/erx411] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/25/2017] [Indexed: 05/05/2023]
Abstract
Plant U-box type E3 ubiquitin ligases (PUBs) are well known for their functions in a variety of stress responses, including immune responses and the adaptation to abiotic stresses. First linked to pollen self-incompatibility, their repertoire of roles has grown to encompass also the regulation of developmental processes. Notably, new studies provide clues to their mode of action, underline the existence of conserved PUB-kinase modules, and suggest new links to G-protein signalling, placing PUBs at the crossroads of major signalling hubs. The frequent association with membranes, by interacting and/or targeting membrane proteins, as well as through a recently reported direct interaction with phospholipids, indicates a general function in the control of vesicle transport and their cargoes. This review aims to give an overview of the most significant advances in the field, while also trying to identify common themes of PUB function.
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Affiliation(s)
- Marco Trujillo
- Independent Junior Research Group-Ubiquitination in Immunity, Leibniz Institute of Plant Biochemistry, Germany
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91
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Abstract
The ubiquitin-proteasome system (UPS) plays a key role in maintaining proteostasis by degrading most of the cellular proteins. Traditionally, UPS activity is studied in vitro, in yeast, or in mammalian cell cultures by using short-lived GFP-based UPS reporters. Here, we present protocols for two fluorescent tools facilitating real-time imaging of UPS activity in living animals. We have generated transgenic Caenorhabditis elegans (C. elegans) expressing a photoconvertible UbG76V-Dendra2 UPS reporter, which permits measurement of reporter degradation by the proteasome independently of reporter protein synthesis, and a fluorescent polyubiquitin-binding reporter for detection of the endogenous pool of Lys48-linked polyubiquitinated proteasomal substrates. These reporter systems facilitate cell- and tissue-specific analysis of UPS activity especially in young adult animals, but can also be used for studies during development, aging, and for example stress conditions.
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92
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Kandasamy G, Andréasson C. Hsp70-Hsp110 chaperones deliver ubiquitin dependent and independent substrates to the 26S proteasome for proteolysis. J Cell Sci 2018; 131:jcs.210948. [DOI: 10.1242/jcs.210948] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 02/14/2018] [Indexed: 02/01/2023] Open
Abstract
In protein quality control, proteotoxic misfolded proteins are recognized by molecular chaperones, ubiquitylated by dedicated quality-control ligases and delivered to 26S proteasome for degradation. The chaperone Hsp70 and its nucleotide exchange factor Hsp110 functions in the degradation of misfolded proteins by the ubiquitin-proteasome system via poorly understood mechanisms. Here we report that yeast Hsp110 (Sse1 and Sse2) functions in the degradation of Hsp70-associated ubiquitin conjugates at the post-ubiquitylation step and is required for the proteasomal degradation of ubiquitin-independent substrates. Hsp110 associates with the 19S regulatory particle of the 26S proteasome and interacts with Hsp70 to facilitate the delivery of Hsp70 substrates for proteasomal degradation. Using a highly defined ubiquitin-independent proteasome substrate we show that the mere introduction of a single Hsp70-binding site renders its degradation dependent on Hsp110. The findings define a dedicated and chaperone-dependent pathway for the efficient shuttling of cellular proteins to the proteasome with profound implications for understanding protein quality control and cellular stress management.
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Affiliation(s)
- Ganapathi Kandasamy
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Sweden
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93
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Moreno-Gonzalo O, Fernandez-Delgado I, Sanchez-Madrid F. Post-translational add-ons mark the path in exosomal protein sorting. Cell Mol Life Sci 2018; 75:1-19. [PMID: 29080091 PMCID: PMC11105655 DOI: 10.1007/s00018-017-2690-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/11/2017] [Accepted: 10/23/2017] [Indexed: 02/07/2023]
Abstract
Extracellular vesicles (EVs) are released by cells to the extracellular environment to mediate inter-cellular communication. Proteins, lipids, nucleic acids and metabolites shuttled in these vesicles modulate specific functions in recipient cells. The enrichment of selected sets of proteins in EVs compared with global cellular levels suggests the existence of specific sorting mechanisms to specify EV loading. Diverse post-translational modifications (PTMs) of proteins participate in the loading of specific elements into EVs. In this review, we offer a perspective on PTMs found in EVs and discuss the specific role of some PTMs, specifically Ubiquitin and Ubiquitin-like modifiers, in exosomal sorting of protein components. The understanding of these mechanisms will provide new strategies for biomedical applications. Examples include the presence of defined PTM marks on EVs as novel biomarkers for the diagnosis and prognosis of certain diseases, or the specific import of immunogenic components into EVs for vaccine generation.
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Affiliation(s)
- Olga Moreno-Gonzalo
- Vascular Pathophysiology Research Area, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Servicio de Inmunología, Instituto Investigación Sanitaria Princesa, Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Irene Fernandez-Delgado
- Vascular Pathophysiology Research Area, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
- Servicio de Inmunología, Instituto Investigación Sanitaria Princesa, Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Francisco Sanchez-Madrid
- Vascular Pathophysiology Research Area, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain.
- Servicio de Inmunología, Instituto Investigación Sanitaria Princesa, Universidad Autónoma de Madrid (UAM), Madrid, Spain.
- CIBERCV, Madrid, Spain.
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94
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Barrado-Gil L, Galindo I, Martínez-Alonso D, Viedma S, Alonso C. The ubiquitin-proteasome system is required for African swine fever replication. PLoS One 2017; 12:e0189741. [PMID: 29244872 PMCID: PMC5731689 DOI: 10.1371/journal.pone.0189741] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/30/2017] [Indexed: 01/28/2023] Open
Abstract
Several viruses manipulate the ubiquitin-proteasome system (UPS) to initiate a productive infection. Determined viral proteins are able to change the host’s ubiquitin machinery and some viruses even encode their own ubiquitinating or deubiquitinating enzymes. African swine fever virus (ASFV) encodes a gene homologous to the E2 ubiquitin conjugating (UBC) enzyme. The viral ubiquitin-conjugating enzyme (UBCv1) is expressed throughout ASFV infection and accumulates at late times post infection. UBCv is also present in the viral particle suggesting that the ubiquitin-proteasome pathway could play an important role at early ASFV infection. We determined that inhibition of the final stage of the ubiquitin-proteasome pathway blocked a post-internalization step in ASFV replication in Vero cells. Under proteasome inhibition, ASF viral genome replication, late gene expression and viral production were severely reduced. Also, ASFV enhanced proteasome activity at late times and the accumulation of polyubiquitinated proteins surrounding viral factories. Core-associated and/or viral proteins involved in DNA replication may be targets for the ubiquitin-proteasome pathway that could possibly assist virus uncoating at final core breakdown and viral DNA release. At later steps, polyubiquitinated proteins at viral factories could exert regulatory roles in cell signaling.
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Affiliation(s)
- Lucía Barrado-Gil
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Madrid, Spain
| | - Inmaculada Galindo
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Madrid, Spain
| | - Diego Martínez-Alonso
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Madrid, Spain
| | - Sergio Viedma
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Madrid, Spain
| | - Covadonga Alonso
- Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, INIA, Madrid, Spain
- * E-mail:
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95
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Kwon YT, Ciechanover A. The Ubiquitin Code in the Ubiquitin-Proteasome System and Autophagy. Trends Biochem Sci 2017; 42:873-886. [DOI: 10.1016/j.tibs.2017.09.002] [Citation(s) in RCA: 374] [Impact Index Per Article: 53.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/05/2017] [Accepted: 09/07/2017] [Indexed: 12/14/2022]
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96
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High-throughput proteome analysis reveals targeted TRPM8 degradation in prostate cancer. Oncotarget 2017; 8:12877-12890. [PMID: 28039451 PMCID: PMC5355063 DOI: 10.18632/oncotarget.14178] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/22/2016] [Indexed: 02/03/2023] Open
Abstract
The Ca2+-permeable ion channel TRPM8 is a hallmark of the prostate epithelium. We recently discovered that TRPM8 is an ionotropic testosterone receptor. This finding suggested that testosterone-induced TRPM8 activity regulates Ca2+ homeostasis in the prostate epithelium. Since androgens are significantly implicated in prostate cancer development, the role of the novel testosterone receptor TRPM8 in cancer was assessed in our study. Although TRPM8 mRNA levels increase at the early prostate cancer stages, we found that it is not proportionally translated into TRPM8 protein levels. High-throughput proteome analysis revealed that TRPM8 degradation is enhanced in human prostate cancer cells. This degradation is executed via a dual degradation mechanism with the involvement of both lysosomal and proteasomal proteolytic pathways. The evaluation of the TRPM8 expression pattern in prostate cancer patients further confirmed the incidence of TRPM8 removal from the plasma membrane and its internalization pattern coincided with the severity of the tumor. Together, our results indicate that enhanced TRPM8 hydrolysis in prostate cancer could present an adaptation mechanism, sustained via bypassing testosterone-induced rapid Ca2+ uptake through TRPM8, thus, diminishing the rates of apoptosis. In this light, recovery of TRPM8 may pose a novel therapeutic strategy for an anti-tumor defense mechanism.
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97
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Zhang M, Zhang GQ, Kang HH, Zhou SM, Wang W. TaPUB1, a Putative E3 Ligase Gene from Wheat, Enhances Salt Stress Tolerance in Transgenic Nicotiana benthamiana. PLANT & CELL PHYSIOLOGY 2017; 58:1673-1688. [PMID: 29016965 DOI: 10.1093/pcp/pcx101] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 07/15/2017] [Indexed: 05/25/2023]
Abstract
High salinity is one of the most severe environmental stresses and limits the growth and yield of diverse crop plants. We isolated a gene named TaPUB1 from wheat (Triticum aestivum L. cv HF9703) that encodes a novel protein containing a U-box domain, the precursor RNA processing 19p (Prp19) superfamily and WD-40 repeats. Real-time reverse transcription-PCR analysis showed that TaPUB1 transcript accumulation was up-regulated by high salinity, drought and phytohormones, suggesting that it plays a role in the abiotic-related defense response. We overexpressed TaPUB1 in Nicotiana benthamiana to evaluate the function of TaPUB1 in the regulation of the salt stress response. Transgenic N. benthamiana plants (OE) with constitutively overexpressed TaPUB1 under the control of the Cauliflower mosaic virus 35S (CaMV 35S) promoter exhibited a higher germination rate, less growth inhibition, less Chl loss and higher photosynthetic capacity than wild-type (WT) plants under salt stress conditions. These results demonstrated the increased tolerance of OE plants to salt stress compared with the WT. The OE plants had lower osmotic potential (OP), reduced Na+ toxicity and less reactive oxygen species accumulation compared with the WT, which may be related to their higher level of osmolytes, lower Na+/K+ ratio and higher antioxidant enzyme activities under salt stress conditions. Consistent with these results, the up-regulated expression of osmic- and antioxidant-related genes in OE plants indicated a role for TaPUB1 in plant salt tolerance.
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Affiliation(s)
- Meng Zhang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
- Collaborative Innovation Center, Jining Medical University, Jining, Shandong 272067, PR China
| | - Guang-Qiang Zhang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
| | - Han-Han Kang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
| | - Shu-Mei Zhou
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
| | - Wei Wang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
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98
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Hochrainer K. Protein Modifications with Ubiquitin as Response to Cerebral Ischemia-Reperfusion Injury. Transl Stroke Res 2017; 9:157-173. [DOI: 10.1007/s12975-017-0567-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 08/11/2017] [Accepted: 08/17/2017] [Indexed: 12/12/2022]
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99
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Gödderz D, Giovannucci TA, Laláková J, Menéndez-Benito V, Dantuma NP. The deubiquitylating enzyme Ubp12 regulates Rad23-dependent proteasomal degradation. J Cell Sci 2017; 130:3336-3346. [PMID: 28966167 DOI: 10.1242/jcs.202622] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 07/31/2017] [Indexed: 01/29/2023] Open
Abstract
The consecutive actions of the ubiquitin-selective segregase Cdc48 and the ubiquitin shuttle factor Rad23 result in the delivery of ubiquitylated proteins at the proteasome. Here, we show that the deubiquitylating enzyme Ubp12 interacts with Cdc48 and regulates proteasomal degradation of Rad23-dependent substrates in Saccharomyces cerevisiae. Overexpression of Ubp12 results in stabilization of Rad23-dependent substrates. We show that Ubp12 removes short ubiquitin chains from the N-terminal ubiquitin-like domain (UbL) of Rad23. Preventing ubiquitylation of Rad23 by mutation of lysine residues within the UbL domain, Rad23UbLK0, does not affect the non-proteolytic role of Rad23 in DNA repair but causes an increase in ubiquitylated cargo bound to the UBA2 domain of Rad23, recapitulating the stabilization of Rad23-dependent substrates observed upon overexpression of Ubp12. Expression of Rad23UbLK0 or overexpression of Ubp12 impairs the ability of yeast to cope with proteotoxic stress, consistent with inefficient clearance of misfolded proteins by the ubiquitin-proteasome system. Our data suggest that ubiquitylation of Rad23 plays a stimulatory role in the degradation of ubiquitylated substrates by the proteasome.
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Affiliation(s)
- Daniela Gödderz
- Department of Cell and Molecular Biology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Tatiana A Giovannucci
- Department of Cell and Molecular Biology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Jana Laláková
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | | | - Nico P Dantuma
- Department of Cell and Molecular Biology, Karolinska Institutet, S-17177 Stockholm, Sweden
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Abstract
A conserved AAA+ ATPase, called Cdc48 in yeast and p97 or VCP in metazoans, plays an essential role in many cellular processes by segregating polyubiquitinated proteins from complexes or membranes. For example, in endoplasmic reticulum (ER)-associated protein degradation (ERAD), Cdc48/p97 pulls polyubiquitinated, misfolded proteins out of the ER and transfers them to the proteasome. Cdc48/p97 consists of an N-terminal domain and two ATPase domains (D1 and D2). Six Cdc48 monomers form a double-ring structure surrounding a central pore. Cdc48/p97 cooperates with a number of different cofactors, which bind either to the N-terminal domain or to the C-terminal tail. The mechanism of Cdc48/p97 action is poorly understood, despite its critical role in many cellular systems. Recent in vitro experiments using yeast Cdc48 and its heterodimeric cofactor Ufd1/Npl4 (UN) have resulted in novel mechanistic insight. After interaction of the substrate-attached polyubiquitin chain with UN, Cdc48 uses ATP hydrolysis in the D2 domain to move the polypeptide through its central pore, thereby unfolding the substrate. ATP hydrolysis in the D1 domain is involved in substrate release from the Cdc48 complex, which requires the cooperation of the ATPase with a deubiquitinase (DUB). Surprisingly, the DUB does not completely remove all ubiquitin molecules; the remaining oligoubiquitin chain is also translocated through the pore. Cdc48 action bears similarities to the translocation mechanisms employed by bacterial AAA ATPases and the eukaryotic 19S subunit of the proteasome, but differs significantly from that of a related type II ATPase, the NEM-sensitive fusion protein (NSF). Many questions about Cdc48/p97 remain unanswered, including how it handles well-folded substrate proteins, how it passes substrates to the proteasome, and how various cofactors modify substrates and regulate its function.
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Affiliation(s)
- Nicholas Bodnar
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Tom Rapoport
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, Boston, MA, USA
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