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Kim J, Byun I, Kim DY, Joh H, Kim HJ, Lee MJ. Targeted protein degradation directly engaging lysosomes or proteasomes. Chem Soc Rev 2024; 53:3253-3272. [PMID: 38369971 DOI: 10.1039/d3cs00344b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Targeted protein degradation (TPD) has been established as a viable alternative to attenuate the function of a specific protein of interest in both biological and clinical contexts. The unique TPD mode-of-action has allowed previously undruggable proteins to become feasible targets, expanding the landscape of "druggable" properties and "privileged" target proteins. As TPD continues to evolve, a range of innovative strategies, which do not depend on recruiting E3 ubiquitin ligases as in proteolysis-targeting chimeras (PROTACs), have emerged. Here, we present an overview of direct lysosome- and proteasome-engaging modalities and discuss their perspectives, advantages, and limitations. We outline the chemical composition, biochemical activity, and pharmaceutical characteristics of each degrader. These alternative TPD approaches not only complement the first generation of PROTACs for intracellular protein degradation but also offer unique strategies for targeting pathologic proteins located on the cell membrane and in the extracellular space.
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Affiliation(s)
- Jiseong Kim
- Department of Biochemistry & Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Insuk Byun
- Department of Biochemistry & Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Do Young Kim
- Department of Chemistry, College of Science, Korea University, Seoul 02841, Korea.
| | - Hyunhi Joh
- Department of Chemistry, College of Science, Korea University, Seoul 02841, Korea.
| | - Hak Joong Kim
- Department of Chemistry, College of Science, Korea University, Seoul 02841, Korea.
| | - Min Jae Lee
- Department of Biochemistry & Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
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Satapathy S, Walker H, Brown J, Gambin Y, Wilson MR. The N-end rule pathway regulates ER stress-induced clusterin release to the cytosol where it directs misfolded proteins for degradation. Cell Rep 2023; 42:113059. [PMID: 37660295 DOI: 10.1016/j.celrep.2023.113059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 06/14/2023] [Accepted: 08/16/2023] [Indexed: 09/05/2023] Open
Abstract
Previous work suggests that cell stress induces release of the normally secreted chaperone clusterin (CLU) into the cytosol. We analyzed the localization of CLU in healthy and stressed cells, the mechanism of its cytosolic release, and its interactions with cytosolic misfolded proteins. Key results of this study are the following: (1) full-length CLU is released to the cytosol during stress, (2) the CLU N-terminal D1 residue is recognized by the N-end rule pathway and together with the enzyme ATE1 is essential for cytosolic release, (3) CLU can form stable complexes with cytosolic misfolded proteins and direct them to the proteasome and autophagosomes, and (4) cytosolic CLU protects cells from hypoxic stress and the cytosolic overexpression of an aggregation-prone protein. Collectively, the results suggest that enhanced cytosolic release of CLU is a stress response that can inhibit the toxicity of misfolded proteins and facilitate their targeted degradation via both autophagy and the proteasome.
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Affiliation(s)
- Sandeep Satapathy
- The Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA; School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia; Molecular Horizons Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Holly Walker
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia; Molecular Horizons Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - James Brown
- EMBL Australia Node in Single Molecule Science, and School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Yann Gambin
- EMBL Australia Node in Single Molecule Science, and School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Mark R Wilson
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia; Molecular Horizons Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
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Macedo-da-Silva J, Rosa-Fernandes L, Gomes VDM, Santiago VF, Santos DM, Molnar CMS, Barboza BR, de Souza EE, Marques RF, Boscardin SB, Durigon EL, Marinho CRF, Wrenger C, Marie SKN, Palmisano G. Protein Arginylation Is Regulated during SARS-CoV-2 Infection. Viruses 2023; 15:v15020290. [PMID: 36851505 PMCID: PMC9964439 DOI: 10.3390/v15020290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/09/2023] [Accepted: 01/17/2023] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND In 2019, the world witnessed the onset of an unprecedented pandemic. By February 2022, the infection by SARS-CoV-2 has already been responsible for the death of more than 5 million people worldwide. Recently, we and other groups discovered that SARS-CoV-2 infection induces ER stress and activation of the unfolded protein response (UPR) pathway. Degradation of misfolded/unfolded proteins is an essential element of proteostasis and occurs mainly in lysosomes or proteasomes. The N-terminal arginylation of proteins is characterized as an inducer of ubiquitination and proteasomal degradation by the N-degron pathway. RESULTS The role of protein arginylation during SARS-CoV-2 infection was elucidated. Protein arginylation was studied in Vero CCL-81, macrophage-like THP1, and Calu-3 cells infected at different times. A reanalysis of in vivo and in vitro public omics data combined with immunoblotting was performed to measure levels of arginyl-tRNA-protein transferase (ATE1) and its substrates. Dysregulation of the N-degron pathway was specifically identified during coronavirus infections compared to other respiratory viruses. We demonstrated that during SARS-CoV-2 infection, there is an increase in ATE1 expression in Calu-3 and Vero CCL-81 cells. On the other hand, infected macrophages showed no enzyme regulation. ATE1 and protein arginylation was variant-dependent, as shown using P1 and P2 viral variants and HEK 293T cells transfection with the spike protein and receptor-binding domains (RBD). In addition, we report that ATE1 inhibitors, tannic acid and merbromine (MER) reduce viral load. This finding was confirmed in ATE1-silenced cells. CONCLUSIONS We demonstrate that ATE1 is increased during SARS-CoV-2 infection and its inhibition has potential therapeutic value.
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Affiliation(s)
- Janaina Macedo-da-Silva
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Livia Rosa-Fernandes
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
- Laboratory of Experimental Immunoparasitology, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Vinicius de Morais Gomes
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Veronica Feijoli Santiago
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Deivid Martins Santos
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | | | - Bruno Rafael Barboza
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Edmarcia Elisa de Souza
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences at the University of São Paulo, São Paulo 05508-000, Brazil
| | - Rodolfo Ferreira Marques
- Laboratory of Antigen Targeting for Dendritic Cells, Department of Parasitology, Institute of Biomedical Sciences at the University of São Paulo, São Paulo 05508-000, Brazil
| | - Silvia Beatriz Boscardin
- Laboratory of Antigen Targeting for Dendritic Cells, Department of Parasitology, Institute of Biomedical Sciences at the University of São Paulo, São Paulo 05508-000, Brazil
| | - Edison Luiz Durigon
- Laboratory of Clinical and Molecular Virology, Department of Microbiology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Claudio Romero Farias Marinho
- Laboratory of Experimental Immunoparasitology, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences at the University of São Paulo, São Paulo 05508-000, Brazil
| | - Suely Kazue Nagahashi Marie
- Laboratory of Molecular and Cellular Biology (LIM 15), Department of Neurology, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 01246-903, Brazil
| | - Giuseppe Palmisano
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo 05508-000, Brazil
- School of Natural Sciences, Macquarie University, Sydney 2109, Australia
- Correspondence: or ; Tel.: +55-11-99920-8662
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Fina ME, Wang J, Vedula P, Tang HY, Kashina A, Dong DW. Arginylation Regulates G-protein Signaling in the Retina. Front Cell Dev Biol 2022; 9:807345. [PMID: 35127722 PMCID: PMC8815403 DOI: 10.3389/fcell.2021.807345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/17/2021] [Indexed: 12/03/2022] Open
Abstract
Arginylation is a post-translational modification mediated by the arginyltransferase (Ate1). We recently showed that conditional deletion of Ate1 in the nervous system leads to increased light-evoked response sensitivities of ON-bipolar cells in the retina, indicating that arginylation regulates the G-protein signaling complexes of those neurons and/or photoreceptors. However, none of the key players in the signaling pathway were previously shown to be arginylated. Here we show that Gαt1, Gβ1, RGS6, and RGS7 are arginylated in the retina and RGS6 and RGS7 protein levels are elevated in Ate1 knockout, suggesting that arginylation plays a direct role in regulating their protein level and the G-protein-mediated responses in the retina.
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Affiliation(s)
- Marie E. Fina
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, United States
| | - Junling Wang
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, United States
| | - Pavan Vedula
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, United States
| | - Hsin-Yao Tang
- Proteomics and Metabolomics Facility, The Wistar Institute, Philadelphia, PA, United States
| | - Anna Kashina
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, United States
- *Correspondence: Anna Kashina, ; Dawei W. Dong,
| | - Dawei W. Dong
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, United States
- Institute for Biomedical Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- *Correspondence: Anna Kashina, ; Dawei W. Dong,
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Jeon JH, Oh TR, Park S, Huh S, Kim JH, Mai BK, Lee JH, Kim SH, Lee MJ. The Antipsychotic Drug Clozapine Suppresses the RGS4 Polyubiquitylation and Proteasomal Degradation Mediated by the Arg/N-Degron Pathway. Neurotherapeutics 2021; 18:1768-1782. [PMID: 33884581 PMCID: PMC8608952 DOI: 10.1007/s13311-021-01039-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2021] [Indexed: 02/04/2023] Open
Abstract
Although diverse antipsychotic drugs have been developed for the treatment of schizophrenia, most of their mechanisms of action remain elusive. Regulator of G-protein signaling 4 (RGS4) has been reported to be linked, both genetically and functionally, with schizophrenia and is a physiological substrate of the arginylation branch of the N-degron pathway (Arg/N-degron pathway). Here, we show that the atypical antipsychotic drug clozapine significantly inhibits proteasomal degradation of RGS4 proteins without affecting their transcriptional expression. In addition, the levels of Arg- and Phe-GFP (artificial substrates of the Arg/N-degron pathway) were significantly elevated by clozapine treatment. In silico computational model suggested that clozapine may interact with active sites of N-recognin E3 ubiquitin ligases. Accordingly, treatment with clozapine resulted in reduced polyubiquitylation of RGS4 and Arg-GFP in the test tube and in cultured cells. Clozapine attenuated the activation of downstream effectors of G protein-coupled receptor signaling, such as MEK1 and ERK1, in HEK293 and SH-SY5Y cells. Furthermore, intraperitoneal injection of clozapine into rats significantly stabilized the endogenous RGS4 protein in the prefrontal cortex. Overall, these results reveal an additional therapeutic mechanism of action of clozapine: this drug posttranslationally inhibits the degradation of Arg/N-degron substrates, including RGS4. These findings imply that modulation of protein post-translational modifications, in particular the Arg/N-degron pathway, may be a novel molecular therapeutic strategy against schizophrenia.
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Affiliation(s)
- Jun Hyoung Jeon
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Tae Rim Oh
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Seoyoung Park
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Sunghoo Huh
- Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Korea
| | - Ji Hyeon Kim
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Jung Hoon Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Se Hyun Kim
- Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Korea.
- Department of Psychiatry, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, 03080, Korea.
| | - Min Jae Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea.
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, Korea.
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6
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Fina ME, Wang J, Nikonov SS, Sterling S, Vardi N, Kashina A, Dong DW. Arginyltransferase (Ate1) regulates the RGS7 protein level and the sensitivity of light-evoked ON-bipolar responses. Sci Rep 2021; 11:9376. [PMID: 33931669 PMCID: PMC8087773 DOI: 10.1038/s41598-021-88628-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/14/2021] [Indexed: 12/16/2022] Open
Abstract
Regulator of G-protein signaling 7 (RGS7) is predominately present in the nervous system and is essential for neuronal signaling involving G-proteins. Prior studies in cultured cells showed that RGS7 is regulated via proteasomal degradation, however no protein is known to facilitate proteasomal degradation of RGS7 and it has not been shown whether this regulation affects G-protein signaling in neurons. Here we used a knockout mouse model with conditional deletion of arginyltransferase (Ate1) in the nervous system and found that in retinal ON bipolar cells, where RGS7 modulates a G-protein to signal light increments, deletion of Ate1 raised the level of RGS7. Electroretinographs revealed that lack of Ate1 leads to increased light-evoked response sensitivities of ON-bipolar cells, as well as their downstream neurons. In cultured mouse embryonic fibroblasts (MEF), RGS7 was rapidly degraded via proteasome pathway and this degradation was abolished in Ate1 knockout MEF. Our results indicate that Ate1 regulates RGS7 protein level by facilitating proteasomal degradation of RGS7 and thus affects G-protein signaling in neurons.
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Affiliation(s)
- Marie E Fina
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Junling Wang
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Sergei S Nikonov
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Stephanie Sterling
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Noga Vardi
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Anna Kashina
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Dawei W Dong
- Department of Biomedical Sciences, School of Veterinary Medicines, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Institute for Biomedical Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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7
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Kim JH, Lee J, Choi WH, Park S, Park SH, Lee JH, Lim SM, Mun JY, Cho HS, Han D, Suh YH, Lee MJ. CHIP-mediated hyperubiquitylation of tau promotes its self-assembly into the insoluble tau filaments. Chem Sci 2021; 12:5599-5610. [PMID: 34168795 PMCID: PMC8179656 DOI: 10.1039/d1sc00586c] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/05/2021] [Indexed: 01/08/2023] Open
Abstract
The tau protein is a highly soluble and natively unfolded protein. Under pathological conditions, tau undergoes multiple post-translational modifications (PTMs) and conformational changes to form insoluble filaments, which are the proteinaceous signatures of tauopathies. To dissect the crosstalk among tau PTMs during the aggregation process, we phosphorylated and ubiquitylated recombinant tau in vitro using GSK3β and CHIP, respectively. The resulting phospho-ub-tau contained conventional polyubiquitin chains with lysine 48 linkages, sufficient for proteasomal degradation, whereas unphosphorylated ub-tau species retained only one-three ubiquitin moieties. Mass-spectrometric analysis of in vitro reconstituted phospho-ub-tau revealed seven additional ubiquitylation sites, some of which are known to stabilize tau protofilament stacking in the human brain with tauopathy. When the ubiquitylation reaction was prolonged, phospho-ub-tau transformed into insoluble hyperubiquitylated tau species featuring fibrillar morphology and in vitro seeding activity. We developed a small-molecule inhibitor of CHIP through biophysical screening; this effectively suppressed tau ubiquitylation in vitro and delayed its aggregation in cultured cells including primary cultured neurons. Our biochemical findings point to a "multiple-hit model," where sequential events of tau phosphorylation and hyperubiquitylation function as a key driver of the fibrillization process, thus indicating that targeting tau ubiquitylation may be an effective strategy to alleviate the course of tauopathies.
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Affiliation(s)
- Ji Hyeon Kim
- Department of Biomedical Sciences, Seoul National University Graduate School Seoul 03080 Korea +82 2-744-4534 +82 2-740-8254
| | - Jeeyoung Lee
- Department of Biomedical Sciences, Seoul National University Graduate School Seoul 03080 Korea +82 2-744-4534 +82 2-740-8254
| | - Won Hoon Choi
- Department of Biomedical Sciences, Seoul National University Graduate School Seoul 03080 Korea +82 2-744-4534 +82 2-740-8254
| | - Seoyoung Park
- Department of Biochemistry & Molecular Biology, Neuroscience Research Institute, Seoul National University College of Medicine Seoul 03080 Korea
| | - Seo Hyeong Park
- Department of Biomedical Sciences, Seoul National University Graduate School Seoul 03080 Korea +82 2-744-4534 +82 2-740-8254
| | - Jung Hoon Lee
- Department of Biochemistry & Molecular Biology, Neuroscience Research Institute, Seoul National University College of Medicine Seoul 03080 Korea
| | - Sang Min Lim
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology Seoul 02792 Korea
| | - Ji Young Mun
- Neural Circuit Research Group, Korea Brain Research Institute Daegu 41062 Korea
| | - Hyun-Soo Cho
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University Seoul 03722 Korea
| | - Dohyun Han
- Proteomics Core Facility, Biomedical Research Institute, Seoul National University Hospital Seoul 03080 Korea
| | - Young Ho Suh
- Department of Biomedical Sciences, Seoul National University Graduate School Seoul 03080 Korea +82 2-744-4534 +82 2-740-8254
- Department of Biochemistry & Molecular Biology, Neuroscience Research Institute, Seoul National University College of Medicine Seoul 03080 Korea
| | - Min Jae Lee
- Department of Biomedical Sciences, Seoul National University Graduate School Seoul 03080 Korea +82 2-744-4534 +82 2-740-8254
- Department of Biochemistry & Molecular Biology, Neuroscience Research Institute, Seoul National University College of Medicine Seoul 03080 Korea
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8
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Docosahexaenoic Acid, a Potential Treatment for Sarcopenia, Modulates the Ubiquitin-Proteasome and the Autophagy-Lysosome Systems. Nutrients 2020; 12:nu12092597. [PMID: 32859116 PMCID: PMC7551806 DOI: 10.3390/nu12092597] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 12/14/2022] Open
Abstract
One of the characteristic features of aging is the progressive loss of muscle mass, a nosological syndrome called sarcopenia. It is also a pathologic risk factor for many clinically adverse outcomes in older adults. Therefore, delaying the loss of muscle mass, through either boosting muscle protein synthesis or slowing down muscle protein degradation using nutritional supplements could be a compelling strategy to address the needs of the world’s aging population. Here, we review the recently identified properties of docosahexaenoic acid (DHA). It was shown to delay muscle wasting by stimulating intermediate oxidative stress and inhibiting proteasomal degradation of muscle proteins. Both the ubiquitin–proteasome and the autophagy–lysosome systems are modulated by DHA. Collectively, growing evidence indicates that DHA is a potent pharmacological agent that could improve muscle homeostasis. Better understanding of cellular proteolytic systems associated with sarcopenia will allow us to identify novel therapeutic interventions, such as omega-3 polyunsaturated fatty acids, to treat this disease.
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9
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Avcilar-Kucukgoze I, Gamper H, Polte C, Ignatova Z, Kraetzner R, Shtutman M, Hou YM, Dong DW, Kashina A. tRNA Arg-Derived Fragments Can Serve as Arginine Donors for Protein Arginylation. Cell Chem Biol 2020; 27:839-849.e4. [PMID: 32553119 DOI: 10.1016/j.chembiol.2020.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/12/2020] [Accepted: 05/27/2020] [Indexed: 12/23/2022]
Abstract
Arginyltransferase ATE1 mediates posttranslational arginylation and plays key roles in multiple physiological processes. ATE1 utilizes arginyl (Arg)-tRNAArg as the donor of Arg, putting this reaction into a direct competition with the protein synthesis machinery. Here, we address the question of ATE1- Arg-tRNAArg specificity as a potential mechanism enabling this competition in vivo. Using in vitro arginylation assays and Ate1 knockout models, we find that, in addition to full-length tRNA, ATE1 is also able to utilize short tRNAArg fragments that bear structural resemblance to tRNA-derived fragments (tRF), a recently discovered class of small regulatory non-coding RNAs with global emerging biological role. Ate1 knockout cells show a decrease in tRFArg generation and a significant increase in the ratio of tRNAArg:tRFArg compared with wild type, suggesting a functional link between tRFArg and arginylation. We propose that generation of physiologically important tRFs can serve as a switch between translation and protein arginylation.
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Affiliation(s)
- Irem Avcilar-Kucukgoze
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Howard Gamper
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19144, USA
| | - Christine Polte
- Institute of Biochemistry and Molecular Biology, University of Hamburg, 20148 Hamburg, Germany
| | - Zoya Ignatova
- Institute of Biochemistry and Molecular Biology, University of Hamburg, 20148 Hamburg, Germany
| | - Ralph Kraetzner
- Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Michael Shtutman
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC 29208, USA
| | - Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19144, USA
| | - Dawei W Dong
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Biomedical Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anna Kashina
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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10
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Kim E, Park S, Lee JH, Mun JY, Choi WH, Yun Y, Lee J, Kim JH, Kang MJ, Lee MJ. Dual Function of USP14 Deubiquitinase in Cellular Proteasomal Activity and Autophagic Flux. Cell Rep 2019; 24:732-743. [PMID: 30021169 DOI: 10.1016/j.celrep.2018.06.058] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/15/2018] [Accepted: 06/14/2018] [Indexed: 12/17/2022] Open
Abstract
The ubiquitin-proteasome system and the autophagy-lysosome system are two major intracellular proteolytic pathways in eukaryotes. Although several biochemical mechanisms underlying the crosstalk between them have been suggested, little is known about the effect of enhanced proteasome activity on autophagic flux. Here, we found that upregulation of proteasome activity, which was achieved through the inhibition of USP14, significantly impaired cellular autophagic flux, especially at the autophagosome-lysosome fusion step. UVRAG appeared to function as a crucial checkpoint for the proper progression of autophagic flux. Although proteasome activation through USP14 inhibition facilitated the clearance of microtubule-associated protein tau (MAPT) and reduced the amount of its oligomeric forms, the same conditions increased the formation of inclusion bodies from nonproteasomal substrates such as huntingtin with long polyglutamine repeats. Our results collectively indicate that USP14 may function as a common denominator in the compensatory negative feedback between the two major proteolytic processes in the cell.
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Affiliation(s)
- Eunkyoung Kim
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Seoyoung Park
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jung Hoon Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Ji Young Mun
- Department of Structure and Function of Neural Network, Korea Brain Research Institute, Daegu 41068, Korea
| | - Won Hoon Choi
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Yejin Yun
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Jeeyoung Lee
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Ji Hyeon Kim
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea
| | - Min-Ji Kang
- Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
| | - Min Jae Lee
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Korea; Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.
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11
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Kechko OI, Petrushanko IY, Brower CS, Adzhubei AA, Moskalev AA, Piatkov KI, Mitkevich VA, Makarov AA. Beta-amyloid induces apoptosis of neuronal cells by inhibition of the Arg/N-end rule pathway proteolytic activity. Aging (Albany NY) 2019; 11:6134-6152. [PMID: 31446431 PMCID: PMC6738421 DOI: 10.18632/aging.102177] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 08/09/2019] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is accompanied by the dysfunction of intracellular protein homeostasis systems, in particular the ubiquitin-proteasome system (UPS). Beta-amyloid peptide (Aβ), which is involved in the processes of neurodegeneration in AD, is a substrate of this system, however its effect on UPS activity is still poorly explored. Here we found that Aβ peptides inhibited the proteolytic activity of the antiapoptotic Arg/N-end rule pathway that is a part of UPS. We identified arginyltransferase Ate1 as a specific component of the Arg/N-end rule pathway targeted by Aβs. Aβ bearing the familial English H6R mutation, known to cause early-onset AD, had an even greater inhibitory effect on protein degradation through the Arg/N-end rule pathway than intact Aβ. This effect was associated with a significant decrease in Ate1-1 and Ate1-3 catalytic activity. We also found that the loss of Ate1 in neuroblastoma Neuro-2a cells eliminated the apoptosis-inducing effects of Aβ peptides. Together, our results show that the apoptotic effect of Aβ peptides is linked to their impairment of Ate1 catalytic activity leading to suppression of the Arg/N-end rule pathway proteolytic activity and ultimately cell death.
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Affiliation(s)
- Olga I Kechko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Irina Yu Petrushanko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | | | - Alexei A Adzhubei
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Alexey A Moskalev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia.,Institute of Biology, Komi Science Center, Russian Academy of Sciences, Syktyvkar 167000, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141701, Russia
| | - Konstantin I Piatkov
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Vladimir A Mitkevich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Alexander A Makarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
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12
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Perrar A, Dissmeyer N, Huesgen PF. New beginnings and new ends: methods for large-scale characterization of protein termini and their use in plant biology. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2021-2038. [PMID: 30838411 PMCID: PMC6460961 DOI: 10.1093/jxb/erz104] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 02/27/2019] [Indexed: 05/17/2023]
Abstract
Dynamic regulation of protein function and abundance plays an important role in virtually every aspect of plant life. Diversifying mechanisms at the RNA and protein level result in many protein molecules with distinct sequence and modification, termed proteoforms, arising from a single gene. Distinct protein termini define proteoforms arising from translation of alternative transcripts, use of alternative translation initiation sites, and different co- and post-translational modifications of the protein termini. Also site-specific proteolytic processing by endo- and exoproteases generates truncated proteoforms, defined by distinct protease-generated neo-N- and neo-C-termini, that may exhibit altered activity, function, and localization compared with their precursor proteins. In eukaryotes, the N-degron pathway targets cytosolic proteins, exposing destabilizing N-terminal amino acids and/or destabilizing N-terminal modifications for proteasomal degradation. This enables rapid and selective removal not only of unfolded proteins, but also of substrate proteoforms generated by proteolytic processing or changes in N-terminal modifications. Here we summarize current protocols enabling proteome-wide analysis of protein termini, which have provided important new insights into N-terminal modifications and protein stability determinants, protein maturation pathways, and protease-substrate relationships in plants.
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Affiliation(s)
- Andreas Perrar
- Forschungszentrum Jülich, Central Institute for Engineering, Electronics and Analytics, ZEA-3 Analytics, Jülich, Germany
| | - Nico Dissmeyer
- Independent Junior Research Group on Protein Recognition and Degradation, Leibniz Institute of Plant Biochemistry (IPB), Weinberg, Halle (Saale), Germany
- ScienceCampus Halle – Plant-based Bioeconomy, Halle (Saale), Germany
| | - Pitter F Huesgen
- Forschungszentrum Jülich, Central Institute for Engineering, Electronics and Analytics, ZEA-3 Analytics, Jülich, Germany
- Medical Faculty and University Hospital, University of Cologne, Cologne, Germany
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13
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May DH, Tamura K, Noble WS. Detecting Modifications in Proteomics Experiments with Param-Medic. J Proteome Res 2019; 18:1902-1906. [PMID: 30714740 DOI: 10.1021/acs.jproteome.8b00954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Searching tandem mass spectra against a peptide database requires accurate knowledge of various experimental parameters, including machine settings and details of the sample preparation protocol. In some cases, such as in reanalysis of public data sets, this experimental metadata may be missing or inaccurate. We describe a method for automatically inferring the presence of various types of modifications, including stable-isotope and isobaric labeling and tandem mass tags as well as the enrichment of phosphorylated peptides, directly from a given set of mass spectra. We demonstrate the sensitivity and specificity of the proposed approach, and we provide open-source Python and C++ implementations in a new version of the software tool Param-Medic.
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Affiliation(s)
- Damon H May
- Department of Genome Sciences , University of Washington , Seattle , Washington 98195 , United States
| | - Kaipo Tamura
- Department of Genome Sciences , University of Washington , Seattle , Washington 98195 , United States
| | - William S Noble
- Department of Genome Sciences , University of Washington , Seattle , Washington 98195 , United States.,Paul G. Allen School of Computer Science and Engineering , University of Washington , Seattle , Washington 98195 , United States
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14
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Singh A, Borah AK, Deka K, Gogoi AP, Verma K, Barah P, Saha S. Arginylation regulates adipogenesis by regulating expression of PPARγ at transcript and protein level. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:596-607. [DOI: 10.1016/j.bbalip.2018.12.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 11/28/2022]
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15
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Hwang S, Yun Y, Choi WH, Kim SB, Shin J, Lee MJ, Oh DC. Acidiphilamides A-E, Modified Peptides as Autophagy Inhibitors from an Acidophilic Actinobacterium, Streptacidiphilus rugosus. JOURNAL OF NATURAL PRODUCTS 2019; 82:341-348. [PMID: 30735389 DOI: 10.1021/acs.jnatprod.8b00828] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Five new tripeptides, acidiphilamides A-E (1-5), were discovered along with two previously reported compounds, l-isoleucinamide (6) and l-valinamide (7), from Streptacidiphilus rugosus AM-16, an acidophilic actinobacterial strain isolated from acidic forest soil. The structures of 1-5 were elucidated as modified tripeptides bearing phenylalaninol or methioninol fragments with C3-C5 acyl chains based mainly on NMR and mass spectroscopic data. The absolute configurations of the amine units were established by advanced Marfey's method and GITC (2,3,4,6-tetra- O-acetyl-β-d-glucopyranosyl isothiocyanate) derivatization followed by LC/MS analysis. Acidiphilamides A and B (1 and 2), the first secondary metabolites isolated from the rare actinobacterial genus Streptacidiphilus, significantly inhibited autophagic flux but not proteasome activity in HeLa cells. These compounds appeared to block mainly the autophagosome-lysosome fusion step in the late stage of cellular autophagy.
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Affiliation(s)
- Sunghoon Hwang
- Natural Products Research Institute, College of Pharmacy , Seoul National University , 1 Gwanak-ro , Gwanak-gu, Seoul 08826 , Republic of Korea
| | - Yejin Yun
- Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul 03080 , Republic of Korea
| | - Won Hoon Choi
- Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul 03080 , Republic of Korea
| | - Seung Bum Kim
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology , Chungnam National University , Daejeon 34134 , Republic of Korea
| | - Jongheon Shin
- Natural Products Research Institute, College of Pharmacy , Seoul National University , 1 Gwanak-ro , Gwanak-gu, Seoul 08826 , Republic of Korea
| | - Min Jae Lee
- Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul 03080 , Republic of Korea
| | - Dong-Chan Oh
- Natural Products Research Institute, College of Pharmacy , Seoul National University , 1 Gwanak-ro , Gwanak-gu, Seoul 08826 , Republic of Korea
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16
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Rassier DE, Kashina A. Protein arginylation of cytoskeletal proteins in the muscle: modifications modifying function. Am J Physiol Cell Physiol 2019; 316:C668-C677. [PMID: 30789755 DOI: 10.1152/ajpcell.00500.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The cytoskeleton drives many essential processes in normal physiology, and its impairments underlie many diseases, including skeletal myopathies, cancer, and heart failure, that broadly affect developed countries worldwide. Cytoskeleton regulation is a field of investigation of rapidly emerging global importance and a new venue for the development of potential therapies. This review overviews our present understanding of the posttranslational regulation of the muscle cytoskeleton through arginylation, a tRNA-dependent addition of arginine to proteins mediated by arginyltransferase 1. We focus largely on arginylation-dependent regulation of striated muscles, shown to play critical roles in facilitating muscle integrity, contractility, regulation, and strength.
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Affiliation(s)
- Dilson E Rassier
- Department of Kinesiology and Physical Education, McGill University , Montreal, Quebec , Canada
| | - Anna Kashina
- Department of Biomedical Sciences, University of Pennsylvania , Philadelphia, Pennsylvania
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17
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Park S, Lee JH, Jeon JH, Lee MJ. Degradation or aggregation: the ramifications of post-translational modifications on tau. BMB Rep 2018; 51:265-273. [PMID: 29661268 PMCID: PMC6033068 DOI: 10.5483/bmbrep.2018.51.6.077] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Indexed: 01/06/2023] Open
Abstract
Tau protein is encoded in the microtubule-associated protein tau (MAPT) gene and contributes to the stability of microtubules in axons. Despite of its basic isoelectric point and high solubility, tau is often found in intraneuronal filamentous inclusions such as paired helical filaments (PHFs), which are the primary constituent of neurofibrillary tangles (NFTs). This pathological feature is the nosological entity termed "tauopathies" which notably include Alzheimer's disease (AD). A proteinaceous signature of all tauopathies is hyperphosphorylation of the accumulated tau, which has been extensively studied as a major pharmacological target for AD therapy. However, in addition to phosphorylation events, tau undergoes a number of diverse posttranslational modifications (PTMs) which appear to be controlled by complex crosstalk. It remains to be elucidated which of the PTMs or their combinations have pro-aggregation or anti-aggregation properties. In this review, we outline the consequences of and communications between several key PTMs of tau, such as acetylation, phosphorylation, and ubiquitination, focusing on their roles in aggregation and degradation. We place emphasis on the structure of tau protofilaments from the human AD brain, which may be good targets to modulate etiological PTMs which cause tau aggregation. [BMB Reports 2018; 51(6): 265-273].
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Affiliation(s)
- Seoyoung Park
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080,
Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080,
Korea
| | - Jung Hoon Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080,
Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080,
Korea
| | - Jun Hyoung Jeon
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080,
Korea
| | - Min Jae Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080,
Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080,
Korea
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080,
Korea
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18
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Eldeeb MA, Leitao LCA, Fahlman RP. Emerging branches of the N-end rule pathways are revealing the sequence complexities of N-termini dependent protein degradation. Biochem Cell Biol 2017; 96:289-294. [PMID: 29253354 DOI: 10.1139/bcb-2017-0274] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The N-end rule links the identity of the N-terminal amino acid of a protein to its in vivo half-life, as some N-terminal residues confer metabolic instability to a protein via their recognition by the cellular machinery that targets them for degradation. Since its discovery, the N-end rule has generally been defined as set of rules of whether an N-terminal residue is stabilizing or not. However, recent studies are revealing that the N-terminal code of amino acids conferring protein instability is more complex than previously appreciated, as recent investigations are revealing that the identity of adjoining downstream residues can also influence the metabolic stability of N-end rule substrate. This is exemplified by the recent discovery of a new branch of N-end rule pathways that target proteins bearing N-terminal proline. In addition, recent investigations are demonstrating that the molecular machinery in N-termini dependent protein degradation may also target proteins for lysosomal degradation, in addition to proteasome-dependent degradation. Herein, we describe some of the recent advances in N-end rule pathways and discuss some of the implications regarding the emerging additional sequence requirements.
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Affiliation(s)
- Mohamed A Eldeeb
- a Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.,b Department of Chemistry, Faculty of Science, Cairo University, Giza, Cairo, Egypt
| | - Luana C A Leitao
- a Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Richard P Fahlman
- a Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.,c Department of Oncology, University of Alberta, Edmonton, AB T6G 2H7, Canada
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19
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Wang J, Han X, Leu NA, Sterling S, Kurosaka S, Fina M, Lee VM, Dong DW, Yates JR, Kashina A. Protein arginylation targets alpha synuclein, facilitates normal brain health, and prevents neurodegeneration. Sci Rep 2017; 7:11323. [PMID: 28900170 PMCID: PMC5595787 DOI: 10.1038/s41598-017-11713-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/29/2017] [Indexed: 12/15/2022] Open
Abstract
Alpha synuclein (α-syn) is a central player in neurodegeneration, but the mechanisms triggering its pathology are not fully understood. Here we found that α-syn is a highly efficient substrate for arginyltransferase ATE1 and is arginylated in vivo by a novel mid-chain mechanism that targets the acidic side chains of E46 and E83. Lack of arginylation leads to increased α-syn aggregation and causes the formation of larger pathological aggregates in neurons, accompanied by impairments in its ability to be cleared via normal degradation pathways. In the mouse brain, lack of arginylation leads to an increase in α-syn’s insoluble fraction, accompanied by behavioral changes characteristic for neurodegenerative pathology. Our data show that lack of arginylation in the brain leads to neurodegeneration, and suggests that α-syn arginylation can be a previously unknown factor that facilitates normal α-syn folding and function in vivo.
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Affiliation(s)
- Junling Wang
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, 19104, USA
| | - Xuemei Han
- The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Nicolae Adrian Leu
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, 19104, USA
| | - Stephanie Sterling
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, 19104, USA
| | - Satoshi Kurosaka
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, 19104, USA
| | - Marie Fina
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, 19104, USA
| | - Virginia M Lee
- University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Dawei W Dong
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, 19104, USA.,Institute for Biomedical Informatics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, USA
| | - John R Yates
- The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Anna Kashina
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, 19104, USA.
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20
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The Protective Roles of ROS-Mediated Mitophagy on 125I Seeds Radiation Induced Cell Death in HCT116 Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:9460462. [PMID: 28119765 PMCID: PMC5227180 DOI: 10.1155/2016/9460462] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 11/18/2016] [Accepted: 11/24/2016] [Indexed: 11/17/2022]
Abstract
For many unresectable carcinomas and locally recurrent cancers (LRC), 125I seeds brachytherapy is a feasible, effective, and safe treatment. Several studies have shown that 125I seeds radiation exerts anticancer activity by triggering DNA damage. However, recent evidence shows mitochondrial quality to be another crucial determinant of cell fate, with mitophagy playing a central role in this control mechanism. Herein, we found that 125I seeds irradiation injured mitochondria, leading to significantly elevated mitochondrial and intracellular ROS (reactive oxygen species) levels in HCT116 cells. The accumulation of mitochondrial ROS increased the expression of HIF-1α and its target genes BINP3 and NIX (BINP3L), which subsequently triggered mitophagy. Importantly, 125I seeds radiation induced mitophagy promoted cells survival and protected HCT116 cells from apoptosis. These results collectively indicated that 125I seeds radiation triggered mitophagy by upregulating the level of ROS to promote cellular homeostasis and survival. The present study uncovered the critical role of mitophagy in modulating the sensitivity of tumor cells to radiation therapy and suggested that chemotherapy targeting on mitophagy might improve the efficiency of 125I seeds radiation treatment, which might be of clinical significance in tumor therapy.
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21
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Lee JH, Lee MJ. Isolation and Characterization of RNA Aptamers against a Proteasome-Associated Deubiquitylating Enzyme UCH37. Chembiochem 2016; 18:171-175. [PMID: 27930845 DOI: 10.1002/cbic.201600515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Indexed: 11/08/2022]
Abstract
Deubiquitylating (DUB) enzymes antagonize ubiquitin-dependent protein degradation both before and after the substrates are engaged with proteasomes. UCH37 is one of three proteasome-associated DUB enzymes in mammals and the only protease among them from the ubiquitin carboxyl-terminal hydrolase (UCH) family. Here, we report the identification of specific RNA aptamers for UCH37 through in vitro selection, and we describe their inhibitory effects on the DUB activity of UCH37. The RNA aptamers significantly delayed RPN13-mediated UCH37 activation and lowered total DUB activity of proteasomes, as measured by the hydrolysis of ubiquitin-rhodamine 110. In addition, the UCH37 aptamers efficiently facilitated the hydrolysis of peptide-based reporter substrates of proteasomes. Thus, the UCH37 aptamers might offer a possible strategy for removing toxic cellular proteins through enhancing proteasome activity.
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Affiliation(s)
- Jung Hoon Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Min Jae Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, 03080, Korea
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