1
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Andor A, Mohanraj M, Pató ZA, Úri K, Biri-Kovács B, Cheng Q, Arnér ESJ. TXNL1 has dual functions as a redox active thioredoxin-like protein as well as an ATP- and redox-independent chaperone. Redox Biol 2023; 67:102897. [PMID: 37804695 PMCID: PMC10570131 DOI: 10.1016/j.redox.2023.102897] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/17/2023] [Accepted: 09/18/2023] [Indexed: 10/09/2023] Open
Abstract
TXNL1 (also named TRP32, for thioredoxin related protein of 32 kDa) is a cytosolic thioredoxin-fold protein expressed in all cell types and conserved from yeast to mammals, but with yet poorly known function. Here, we expressed and purified human TXNL1 together with several Cys-to-Ser variants, characterizing their enzymatic properties. TXNL1 could reduce disulfides in insulin, cystine and glutathione disulfide (GSSG) in reactions coupled to thioredoxin reductase (TXNRD1, TrxR1) using NADPH, similarly to thioredoxin (TXN, Trx1), but with lower catalytic efficacy due to at least one order of magnitude higher Km of TrxR1 for TXNL1 compared to Trx1. However, in sharp contrast to Trx1, we found that TXNL1 also had efficient chaperone activity that did not require ATP. TXNL1 made non-covalent complexes with reduced insulin, thereby keeping it in solution, and TXNL1 provided chaperone function towards whole cell lysate proteins by preventing their aggregation during heating. The chaperone activities of TXNL1 did not require its redox activity or any dithiol-disulfide exchange reactions, as revealed using Cys-to-Ser substituted variants, as well as a maintained chaperone activity of TXNL1 also in the absence of TrxR1 and NADPH. These results reveal that TXNL1 has dual functions, supporting TrxR1-driven redox activities in disulfide reduction reactions, as well as being an ATP-independent chaperone that does not require involvement of its redox activity.
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Affiliation(s)
- Attila Andor
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary; Division of Biochemistry, Department of Medical Biochemistry, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Mahendravarman Mohanraj
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary; Division of Biochemistry, Department of Medical Biochemistry, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Zsuzsanna Anna Pató
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary; Division of Biochemistry, Department of Medical Biochemistry, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Katalin Úri
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary; Division of Biochemistry, Department of Medical Biochemistry, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Beáta Biri-Kovács
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary; Division of Biochemistry, Department of Medical Biochemistry, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Qing Cheng
- Division of Biochemistry, Department of Medical Biochemistry, Karolinska Institutet, SE-171 77, Stockholm, Sweden
| | - Elias S J Arnér
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, 1122, Budapest, Hungary; Division of Biochemistry, Department of Medical Biochemistry, Karolinska Institutet, SE-171 77, Stockholm, Sweden.
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2
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Dreier JE, Prestel A, Martins JM, Brøndum SS, Nielsen O, Garbers AE, Suga H, Boomsma W, Rogers JM, Hartmann-Petersen R, Kragelund BB. A context-dependent and disordered ubiquitin-binding motif. Cell Mol Life Sci 2022; 79:484. [PMID: 35974206 PMCID: PMC9381478 DOI: 10.1007/s00018-022-04486-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/06/2022] [Accepted: 07/14/2022] [Indexed: 02/07/2023]
Abstract
Ubiquitin is a small, globular protein that is conjugated to other proteins as a posttranslational event. A palette of small, folded domains recognizes and binds ubiquitin to translate and effectuate this posttranslational signal. Recent computational studies have suggested that protein regions can recognize ubiquitin via a process of folding upon binding. Using peptide binding arrays, bioinformatics, and NMR spectroscopy, we have uncovered a disordered ubiquitin-binding motif that likely remains disordered when bound and thus expands the palette of ubiquitin-binding proteins. We term this motif Disordered Ubiquitin-Binding Motif (DisUBM) and find it to be present in many proteins with known or predicted functions in degradation and transcription. We decompose the determinants of the motif showing it to rely on features of aromatic and negatively charged residues, and less so on distinct sequence positions in line with its disordered nature. We show that the affinity of the motif is low and moldable by the surrounding disordered chain, allowing for an enhanced interaction surface with ubiquitin, whereby the affinity increases ~ tenfold. Further affinity optimization using peptide arrays pushed the affinity into the low micromolar range, but compromised context dependence. Finally, we find that DisUBMs can emerge from unbiased screening of randomized peptide libraries, featuring in de novo cyclic peptides selected to bind ubiquitin chains. We suggest that naturally occurring DisUBMs can recognize ubiquitin as a posttranslational signal to act as affinity enhancers in IDPs that bind to folded and ubiquitylated binding partners.
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Affiliation(s)
- Jesper E Dreier
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Andreas Prestel
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - João M Martins
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Sebastian S Brøndum
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Olaf Nielsen
- Functional Genomics, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Anna E Garbers
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Wouter Boomsma
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Joseph M Rogers
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen Ø, Denmark
| | - Rasmus Hartmann-Petersen
- REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,The Linderstrøm Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,The Linderstrøm Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.
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3
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Kampmeyer C, Johansen JV, Holmberg C, Karlson M, Gersing SK, Bordallo HN, Kragelund BB, Lerche MH, Jourdain I, Winther JR, Hartmann-Petersen R. Mutations in a Single Signaling Pathway Allow Cell Growth in Heavy Water. ACS Synth Biol 2020; 9:733-748. [PMID: 32142608 DOI: 10.1021/acssynbio.9b00376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Life is completely dependent on water. To analyze the role of water as a solvent in biology, we replaced water with heavy water (D2O) and investigated the biological effects by a wide range of techniques, using Schizosaccharomyces pombe as model organism. We show that high concentrations of D2O lead to altered glucose metabolism and growth retardation. After prolonged incubation in D2O, cells displayed gross morphological changes, thickened cell walls, and aberrant cytoskeletal organization. By transcriptomics and genetic screens, we show that the solvent replacement activates two signaling pathways: (1) the heat-shock response pathway and (2) the cell integrity pathway. Although the heat-shock response system upregulates various chaperones and other stress-relieving enzymes, we find that the activation of this pathway does not offer any fitness advantage to the cells under the solvent-replaced conditions. However, limiting the D2O-triggered activation of the cell integrity pathway allows cell growth when H2O is completely replaced with D2O. The isolated D2O-tolerant strains may aid biological production of deuterated biomolecules.
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Affiliation(s)
- Caroline Kampmeyer
- The Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Jens V. Johansen
- Biotech Research and Innovation Centre, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Christian Holmberg
- The Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Magnus Karlson
- Technical University of Denmark, Department of Electrical Engineering, Ørsted Plads, Building 349, DK-2800 Kongens Lyngby, Denmark
| | - Sarah K. Gersing
- The Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Heloisa N. Bordallo
- Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Birthe B. Kragelund
- The Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
- The REPIN Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Mathilde H. Lerche
- Technical University of Denmark, Department of Electrical Engineering, Ørsted Plads, Building 349, DK-2800 Kongens Lyngby, Denmark
| | - Isabelle Jourdain
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Jakob R. Winther
- The Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Rasmus Hartmann-Petersen
- The Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
- The REPIN Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
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4
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Kampmeyer C, Karakostova A, Schenstrøm SM, Abildgaard AB, Lauridsen AM, Jourdain I, Hartmann-Petersen R. The exocyst subunit Sec3 is regulated by a protein quality control pathway. J Biol Chem 2017; 292:15240-15253. [PMID: 28765280 DOI: 10.1074/jbc.m117.789867] [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] [Received: 04/05/2017] [Revised: 07/19/2017] [Indexed: 02/03/2023] Open
Abstract
Exocytosis involves fusion of secretory vesicles with the plasma membrane, thereby delivering membrane proteins to the cell surface and releasing material into the extracellular space. The tethering of the secretory vesicles before membrane fusion is mediated by the exocyst, an essential phylogenetically conserved octameric protein complex. Exocyst biogenesis is regulated by several processes, but the mechanisms by which the exocyst is degraded are unknown. Here, to unravel the components of the exocyst degradation pathway, we screened for extragenic suppressors of a temperature-sensitive fission yeast strain mutated in the exocyst subunit Sec3 (sec3-913). One of the suppressing DNAs encoded a truncated dominant-negative variant of the 26S proteasome subunit, Rpt2, indicating that exocyst degradation is controlled by the ubiquitin-proteasome system. The temperature-dependent growth defect of the sec3-913 strain was gene dosage-dependent and suppressed by blocking the proteasome, Hsp70-type molecular chaperones, the Pib1 E3 ubiquitin-protein ligase, and the deubiquitylating enzyme Ubp3. Moreover, defects in cell septation, exocytosis, and endocytosis in sec3 mutant strains were similarly alleviated by mutation of components in this pathway. We also found that, particularly under stress conditions, wild-type Sec3 degradation is regulated by Pib1 and the 26S proteasome. In conclusion, our results suggest that a cytosolic protein quality control pathway monitors folding and proteasome-dependent turnover of an exocyst subunit and, thereby, controls exocytosis in fission yeast.
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Affiliation(s)
- Caroline Kampmeyer
- From the Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark and
| | - Antonina Karakostova
- From the Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark and
| | - Signe M Schenstrøm
- From the Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark and
| | - Amanda B Abildgaard
- From the Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark and
| | - Anne-Marie Lauridsen
- From the Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark and
| | - Isabelle Jourdain
- the College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Rasmus Hartmann-Petersen
- From the Linderstrøm-Lang Center, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark and
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5
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Boronat S, Domènech A, Carmona M, García-Santamarina S, Bañó MC, Ayté J, Hidalgo E. Lack of a peroxiredoxin suppresses the lethality of cells devoid of electron donors by channelling electrons to oxidized ribonucleotide reductase. PLoS Genet 2017. [PMID: 28640807 PMCID: PMC5501661 DOI: 10.1371/journal.pgen.1006858] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The thioredoxin and glutaredoxin pathways are responsible of recycling several enzymes which undergo intramolecular disulfide bond formation as part of their catalytic cycles such as the peroxide scavengers peroxiredoxins or the enzyme ribonucleotide reductase (RNR). RNR, the rate-limiting enzyme of deoxyribonucleotide synthesis, is an essential enzyme relying on these electron flow cascades for recycling. RNR is tightly regulated in a cell cycle-dependent manner at different levels, but little is known about the participation of electron donors in such regulation. Here, we show that cytosolic thioredoxins Trx1 and Trx3 are the primary electron donors for RNR in fission yeast. Unexpectedly, trx1 transcript and Trx1 protein levels are up-regulated in a G1-to-S phase-dependent manner, indicating that the supply of electron donors is also cell cycle-regulated. Indeed, genetic depletion of thioredoxins triggers a DNA replication checkpoint ruled by Rad3 and Cds1, with the final goal of up-regulating transcription of S phase genes and constitutive RNR synthesis. Regarding the thioredoxin and glutaredoxin cascades, one combination of gene deletions is synthetic lethal in fission yeast: cells lacking both thioredoxin reductase and cytosolic dithiol glutaredoxin. We have isolated a suppressor of this lethal phenotype: a mutation at the Tpx1-coding gene, leading to a frame shift and a loss-of-function of Tpx1, the main client of electron donors. We propose that in a mutant strain compromised in reducing equivalents, the absence of an abundant and competitive substrate such as the peroxiredoxin Tpx1 has been selected as a lethality suppressor to favor RNR function at the expense of the non-essential peroxide scavenging function, to allow DNA synthesis and cell growth. The essential enzyme ribonucleotide reductase (RNR), the rate-limiting enzyme of deoxyribonucleotide synthesis, relies on the thioredoxin and glutaredoxin electron flow cascades for recycling. RNR is tightly regulated in a cell cycle-dependent manner at different levels. Here, we show that cytosolic thioredoxin Trx1 is the primary electron donor for RNR in fission yeast, and that trx1 transcript and protein levels are up-regulated at G1-to-S phase transition. Genetic depletion of thioredoxins triggers the DNA replication checkpoint up-regulating RNR synthesis. Furthermore, deletion of the genes coding for thioredoxin reductase and dithiol glutaredoxin is synthetic lethal, and we show that a loss-of-function mutation at the peroxiredoxin Tpx1-coding gene acts as a genetic suppressor. We propose that in a mutant strain compromised in reducing equivalents, the absence of an abundant and competitive substrate of redoxins, the peroxiredoxin Tpx1, has been selected as a lethality suppressor to favor channeling of electrons to the essential RNR.
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Affiliation(s)
- Susanna Boronat
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Alba Domènech
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Mercè Carmona
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | | | - M. Carmen Bañó
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Valencia, Spain
| | - José Ayté
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
- * E-mail: (EH); (JA)
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
- * E-mail: (EH); (JA)
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6
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Poulsen EG, Kampmeyer C, Kriegenburg F, Johansen JV, Hofmann K, Holmberg C, Hartmann-Petersen R. UBL/BAG-domain co-chaperones cause cellular stress upon overexpression through constitutive activation of Hsf1. Cell Stress Chaperones 2017; 22:143-154. [PMID: 27966061 PMCID: PMC5225068 DOI: 10.1007/s12192-016-0751-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 12/15/2022] Open
Abstract
As a result of exposure to stress conditions, mutations, or defects during synthesis, cellular proteins are prone to misfold. To cope with such partially denatured proteins, cells mount a regulated transcriptional response involving the Hsf1 transcription factor, which drives the synthesis of molecular chaperones and other stress-relieving proteins. Here, we show that the fission yeast Schizosaccharomyces pombe orthologues of human BAG-1, Bag101, and Bag102, are Hsp70 co-chaperones that associate with 26S proteasomes. Only a subgroup of Hsp70-type chaperones, including Ssa1, Ssa2, and Sks2, binds Bag101 and Bag102 and key residues in the Hsp70 ATPase domains, required for interaction with Bag101 and Bag102, were identified. In humans, BAG-1 overexpression is typically observed in cancers. Overexpression of bag101 and bag102 in fission yeast leads to a strong growth defect caused by triggering Hsp70 to release and activate the Hsf1 transcription factor. Accordingly, the bag101-linked growth defect is alleviated in strains containing a reduced amount of Hsf1 but aggravated in hsp70 deletion strains. In conclusion, we propose that the fission yeast UBL/BAG proteins release Hsf1 from Hsp70, leading to constitutive Hsf1 activation and growth defects.
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Affiliation(s)
- Esben G Poulsen
- The Linderstrøm-Land Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Caroline Kampmeyer
- The Linderstrøm-Land Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Franziska Kriegenburg
- The Linderstrøm-Land Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Jens V Johansen
- Biotech Research and Innovation Centre, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Kay Hofmann
- Institute for Genetics, University of Cologne, 50674, Cologne, Germany
| | - Christian Holmberg
- The Linderstrøm-Land Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark
| | - Rasmus Hartmann-Petersen
- The Linderstrøm-Land Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark.
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7
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Pluskal T, Sajiki K, Becker J, Takeda K, Yanagida M. Diverse fission yeast genes required for responding to oxidative and metal stress: Comparative analysis of glutathione-related and other defense gene deletions. Genes Cells 2016; 21:530-42. [PMID: 27005325 DOI: 10.1111/gtc.12359] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 02/22/2016] [Indexed: 12/25/2022]
Abstract
Living organisms have evolved multiple sophisticated mechanisms to deal with reactive oxygen species. We constructed a collection of twelve single-gene deletion strains of the fission yeast Schizosaccharomyces pombe designed for the study of oxidative and heavy metal stress responses. This collection contains deletions of biosynthetic enzymes of glutathione (Δgcs1 and Δgsa1), phytochelatin (Δpcs2), ubiquinone (Δabc1) and ergothioneine (Δegt1), as well as catalase (Δctt1), thioredoxins (Δtrx1 and Δtrx2), Cu/Zn- and Mn- superoxide dismutases (SODs; Δsod1 and Δsod2), sulfiredoxin (Δsrx1) and sulfide-quinone oxidoreductase (Δhmt2). First, we employed metabolomic analysis to examine the mutants of the glutathione biosynthetic pathway. We found that ophthalmic acid was produced by the same enzymes as glutathione in S. pombe. The identical genetic background of the strains allowed us to assess the severity of the individual gene knockouts by treating the deletion strains with oxidative agents. Among other results, we found that glutathione deletion strains were not particularly sensitive to peroxide or superoxide, but highly sensitive to cadmium stress. Our results show the astonishing diversity in cellular adaptation mechanisms to various types of oxidative and metal stress and provide a useful tool for further research into stress responses.
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Affiliation(s)
- Tomáš Pluskal
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna, Okinawa, Japan
| | - Kenichi Sajiki
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna, Okinawa, Japan
| | - Joanne Becker
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna, Okinawa, Japan
| | - Kojiro Takeda
- Department of Biology, Faculty of Science and Engineering and Institute for Integrative Neurobiology, Konan University, Kobe, Hyogo, Japan
| | - Mitsuhiro Yanagida
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna, Okinawa, Japan
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8
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Mathiassen SG, Larsen IB, Poulsen EG, Madsen CT, Papaleo E, Lindorff-Larsen K, Kragelund BB, Nielsen ML, Kriegenburg F, Hartmann-Petersen R. A Two-step Protein Quality Control Pathway for a Misfolded DJ-1 Variant in Fission Yeast. J Biol Chem 2015; 290:21141-21153. [PMID: 26152728 DOI: 10.1074/jbc.m115.662312] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Indexed: 12/30/2022] Open
Abstract
A mutation, L166P, in the cytosolic protein, PARK7/DJ-1, causes protein misfolding and is linked to Parkinson disease. Here, we identify the fission yeast protein Sdj1 as the orthologue of DJ-1 and calculate by in silico saturation mutagenesis the effects of point mutants on its structural stability. We also map the degradation pathways for Sdj1-L169P, the fission yeast orthologue of the disease-causing DJ-1 L166P protein. Sdj1-L169P forms inclusions, which are enriched for the Hsp104 disaggregase. Hsp104 and Hsp70-type chaperones are required for efficient degradation of Sdj1-L169P. This also depends on the ribosome-associated E3 ligase Ltn1 and its co-factor Rqc1. Although Hsp104 is absolutely required for proteasomal degradation of Sdj1-L169P aggregates, the degradation of already aggregated Sdj1-L169P occurs independently of Ltn1 and Rqc1. Thus, our data point to soluble Sdj1-L169P being targeted early by Ltn1 and Rqc1. The fraction of Sdj1-L169P that escapes this first inspection then forms aggregates that are subsequently cleared via an Hsp104- and proteasome-dependent pathway.
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Affiliation(s)
- Søs G Mathiassen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Ida B Larsen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Esben G Poulsen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Christian T Madsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Elena Papaleo
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Kresten Lindorff-Larsen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Birthe B Kragelund
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Michael L Nielsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Franziska Kriegenburg
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
| | - Rasmus Hartmann-Petersen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
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9
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Nakao LS, Everley RA, Marino SM, Lo SM, de Souza LE, Gygi SP, Gladyshev VN. Mechanism-based proteomic screening identifies targets of thioredoxin-like proteins. J Biol Chem 2015; 290:5685-95. [PMID: 25561728 DOI: 10.1074/jbc.m114.597245] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thioredoxin (Trx)-fold proteins are protagonists of numerous cellular pathways that are subject to thiol-based redox control. The best characterized regulator of thiols in proteins is Trx1 itself, which together with thioredoxin reductase 1 (TR1) and peroxiredoxins (Prxs) comprises a key redox regulatory system in mammalian cells. However, there are numerous other Trx-like proteins, whose functions and redox interactors are unknown. It is also unclear if the principles of Trx1-based redox control apply to these proteins. Here, we employed a proteomic strategy to four Trx-like proteins containing CXXC motifs, namely Trx1, Rdx12, Trx-like protein 1 (Txnl1) and nucleoredoxin 1 (Nrx1), whose cellular targets were trapped in vivo using mutant Trx-like proteins, under conditions of low endogenous expression of these proteins. Prxs were detected as key redox targets of Trx1, but this approach also supported the detection of TR1, which is the Trx1 reductant, as well as mitochondrial intermembrane proteins AIF and Mia40. In addition, glutathione peroxidase 4 was found to be a Rdx12 redox target. In contrast, no redox targets of Txnl1 and Nrx1 could be detected, suggesting that their CXXC motifs do not engage in mixed disulfides with cellular proteins. For some Trx-like proteins, the method allowed distinguishing redox and non-redox interactions. Parallel, comparative analyses of multiple thiol oxidoreductases revealed differences in the functions of their CXXC motifs, providing important insights into thiol-based redox control of cellular processes.
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Affiliation(s)
- Lia S Nakao
- From the Division of Genetics, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, the Universidade Federal do Paraná, Departamento de Patologia Básica, 81531-980, Curitiba, PR, Brazil, and
| | - Robert A Everley
- the Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115
| | - Stefano M Marino
- From the Division of Genetics, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
| | - Sze M Lo
- the Universidade Federal do Paraná, Departamento de Patologia Básica, 81531-980, Curitiba, PR, Brazil, and
| | - Luiz E de Souza
- the Universidade Federal do Paraná, Departamento de Patologia Básica, 81531-980, Curitiba, PR, Brazil, and
| | - Steven P Gygi
- the Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115
| | - Vadim N Gladyshev
- From the Division of Genetics, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115,
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10
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20S proteasome activity is modified via S-glutathionylation based on intracellular redox status of the yeast Saccharomyces cerevisiae: implications for the degradation of oxidized proteins. Arch Biochem Biophys 2014; 557:65-71. [PMID: 24813691 DOI: 10.1016/j.abb.2014.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/11/2014] [Accepted: 05/02/2014] [Indexed: 01/06/2023]
Abstract
Protein S-glutathionylation is a post-translational modification that controls many cellular pathways. Recently, we demonstrated that the α5-subunit of the 20S proteasome is S-glutathionylated in yeast cells grown to the stationary phase in rich medium containing glucose, stimulating 20S core gate opening and increasing the degradation of oxidized proteins. In the present study, we evaluated the correlation between proteasomal S-glutathionylation and the intracellular redox status. The redox status was controlled by growing yeast cells in distinct carbon sources which induced respiratory (glycerol/ethanol) or fermentative (glucose) metabolism. Cells grown under glycerol/ethanol displayed higher reductive power when compared to cells grown under glucose. When purified from cells grown in glucose, 20S proteasome α5-subunit exhibited an intense anti-glutathione labeling. A higher frequency of the open catalytic chamber gate was observed in the S-glutathionylated preparations as demonstrated by transmission electron microscopy. Therefore, cells that had been grown in glucose displayed an increased ability to degrade oxidized proteins. The results of the present study suggest that 20S proteasomal S-glutathionylation is a relevant adaptive response to oxidative stress that is capable to sense the intracellular redox environment, leading to the removal of oxidized proteins via a process that is not dependent upon ubiquitylation and ATP consumption.
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11
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Kriegenburg F, Jakopec V, Poulsen EG, Nielsen SV, Roguev A, Krogan N, Gordon C, Fleig U, Hartmann-Petersen R. A chaperone-assisted degradation pathway targets kinetochore proteins to ensure genome stability. PLoS Genet 2014; 10:e1004140. [PMID: 24497846 PMCID: PMC3907333 DOI: 10.1371/journal.pgen.1004140] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 12/06/2013] [Indexed: 11/19/2022] Open
Abstract
Cells are regularly exposed to stress conditions that may lead to protein misfolding. To cope with this challenge, molecular chaperones selectively target structurally perturbed proteins for degradation via the ubiquitin-proteasome pathway. In mammals the co-chaperone BAG-1 plays an important role in this system. BAG-1 has two orthologues, Bag101 and Bag102, in the fission yeast Schizosaccharomyces pombe. We show that both Bag101 and Bag102 interact with 26S proteasomes and Hsp70. By epistasis mapping we identify a mutant in the conserved kinetochore component Spc7 (Spc105/Blinkin) as a target for a quality control system that also involves, Hsp70, Bag102, the 26S proteasome, Ubc4 and the ubiquitin-ligases Ubr11 and San1. Accordingly, chromosome missegregation of spc7 mutant strains is alleviated by mutation of components in this pathway. In addition, we isolated a dominant negative version of the deubiquitylating enzyme, Ubp3, as a suppressor of the spc7-23 phenotype, suggesting that the proteasome-associated Ubp3 is required for this degradation system. Finally, our data suggest that the identified pathway is also involved in quality control of other kinetochore components and therefore likely to be a common degradation mechanism to ensure nuclear protein homeostasis and genome integrity. The accumulation of misfolded proteins represents a considerable threat to the health of individual cells and has been linked to severe diseases, including cancer and neurodegenerative disorders. To cope with this threat, especially under stress conditions, cells have evolved efficient quality control mechanisms. In general, these rely on molecular chaperones to either seize and refold misfolded proteins, or target them for degradation via the ubiquitin-proteasome system. At present, our understanding of what determines whether a chaperone commits to a folding or a degradation mode is limited. However, studies suggest that association with certain regulatory co-chaperones contributes to this process. Here, we show that certain BAG-1-type co-chaperones function in quality control by targeting misfolded kinetochore components for proteolysis. The presented genetic and biochemical data show that specific ubiquitin conjugating enzymes and ubiquitin-protein ligases maintain nuclear protein homeostasis and are required for upholding genome integrity.
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Affiliation(s)
| | - Visnja Jakopec
- Lehrstuhl für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine Universität, Düsseldorf, Germany
| | - Esben G. Poulsen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Assen Roguev
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - Colin Gordon
- MRC Human Genetics Unit, Western General Hospital, Edinburgh, Scotland, United Kingdom
| | - Ursula Fleig
- Lehrstuhl für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine Universität, Düsseldorf, Germany
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12
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Demasi M, Netto LE, Silva GM, Hand A, de Oliveira CL, Bicev RN, Gozzo F, Barros MH, Leme JM, Ohara E. Redox regulation of the proteasome via S-glutathionylation. Redox Biol 2013; 2:44-51. [PMID: 24396728 PMCID: PMC3881202 DOI: 10.1016/j.redox.2013.12.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 12/04/2013] [Accepted: 12/05/2013] [Indexed: 12/13/2022] Open
Abstract
The proteasome is a multimeric and multicatalytic intracellular protease responsible for the degradation of proteins involved in cell cycle control, various signaling processes, antigen presentation, and control of protein synthesis. The central catalytic complex of the proteasome is called the 20S core particle. The majority of these are flanked on one or both sides by regulatory units. Most common among these units is the 19S regulatory unit. When coupled to the 19S unit, the complex is termed the asymmetric or symmetric 26S proteasome depending on whether one or both sides are coupled to the 19S unit, respectively. The 26S proteasome recognizes poly-ubiquitinylated substrates targeted for proteolysis. Targeted proteins interact with the 19S unit where they are deubiquitinylated, unfolded, and translocated to the 20S catalytic chamber for degradation. The 26S proteasome is responsible for the degradation of major proteins involved in the regulation of the cellular cycle, antigen presentation and control of protein synthesis. Alternatively, the proteasome is also active when dissociated from regulatory units. This free pool of 20S proteasome is described in yeast to mammalian cells. The free 20S proteasome degrades proteins by a process independent of poly-ubiquitinylation and ATP consumption. Oxidatively modified proteins and other substrates are degraded in this manner. The 20S proteasome comprises two central heptamers (β-rings) where the catalytic sites are located and two external heptamers (α-rings) that are responsible for proteasomal gating. Because the 20S proteasome lacks regulatory units, it is unclear what mechanisms regulate the gating of α-rings between open and closed forms. In the present review, we discuss 20S proteasomal gating modulation through a redox mechanism, namely, S-glutathionylation of cysteine residues located in the α-rings, and the consequence of this post-translational modification on 20S proteasomal function.
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Affiliation(s)
- Marilene Demasi
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
| | - Luis E.S. Netto
- Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Gustavo M. Silva
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
- Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Adrian Hand
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
| | | | - Renata N. Bicev
- Departamento de Física Experimental, IF-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Fabio Gozzo
- Instituto de Química, UNICAMP, Campinas, SP, Brazil
| | - Mario H. Barros
- Departamento de Microbiologia, ICB-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Janaina M.M. Leme
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
- Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo, SP, Brazil
| | - Erina Ohara
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil
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13
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Dissection of a Redox Relay: H2O2-Dependent Activation of the Transcription Factor Pap1 through the Peroxidatic Tpx1-Thioredoxin Cycle. Cell Rep 2013; 5:1413-24. [DOI: 10.1016/j.celrep.2013.11.027] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 10/31/2013] [Accepted: 11/14/2013] [Indexed: 11/22/2022] Open
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14
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García-Giménez JL, Seco-Cervera M, Aguado C, Romá-Mateo C, Dasí F, Priego S, Markovic J, Knecht E, Sanz P, Pallardó FV. Lafora disease fibroblasts exemplify the molecular interdependence between thioredoxin 1 and the proteasome in mammalian cells. Free Radic Biol Med 2013; 65:347-359. [PMID: 23850970 DOI: 10.1016/j.freeradbiomed.2013.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 06/27/2013] [Accepted: 07/01/2013] [Indexed: 11/30/2022]
Abstract
Thioredoxin 1 (Trx1) is a key regulator of cellular redox balance and participates in cellular signaling events. Recent evidence from yeast indicates that members of the Trx family interact with the 20S proteasome, indicating redox regulation of proteasome activity. However, there is little information about the interrelationship of Trx proteins with the proteasome system in mammalian cells, especially in the nucleus. Here, we have investigated this relationship under various cellular conditions in mammalian cells. We show that Trx1 levels and its subcellular localization (cytosol, endoplasmic reticulum, and nucleus) depend on proteasome activity during the cell cycle in NIH3T3 fibroblasts and under stress conditions, when proteasomes are inhibited. In addition, we also studied in these cells how the main cellular antioxidant systems are stimulated when proteasome activity is inhibited. Finally, we describe a reduction in Trx1 levels in Lafora disease fibroblasts and demonstrate that the nuclear colocalization of Trx1 with 20S proteasomes in laforin-deficient cells is altered compared with control cells. Our results indicate a close relationship between Trx1 and the 20S nuclear proteasome and give a new perspective to the study of diseases or physiopathological conditions in which defects in the proteasome system are associated with oxidative stress.
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Affiliation(s)
- José Luis García-Giménez
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain; Fundación del Hospital Clínico Universitat de Valencia-INCLIVA, Valencia, Spain; Department of Physiology, University of Valencia, 46010 Valencia, Spain
| | - Marta Seco-Cervera
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Carmen Aguado
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain; Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Carlos Romá-Mateo
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain; Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Francisco Dasí
- Fundación del Hospital Clínico Universitat de Valencia-INCLIVA, Valencia, Spain; Department of Physiology, University of Valencia, 46010 Valencia, Spain
| | - Sonia Priego
- Research Core Facility, Medical School, University of Valencia, 46010 Valencia, Spain
| | - Jelena Markovic
- Research Core Facility, Medical School, University of Valencia, 46010 Valencia, Spain
| | - Erwin Knecht
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain; Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Pascual Sanz
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain; Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Federico V Pallardó
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain; Fundación del Hospital Clínico Universitat de Valencia-INCLIVA, Valencia, Spain; Department of Physiology, University of Valencia, 46010 Valencia, Spain.
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15
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Brown JD, Day AM, Taylor SR, Tomalin LE, Morgan BA, Veal EA. A peroxiredoxin promotes H2O2 signaling and oxidative stress resistance by oxidizing a thioredoxin family protein. Cell Rep 2013; 5:1425-35. [PMID: 24268782 PMCID: PMC3898613 DOI: 10.1016/j.celrep.2013.10.036] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/23/2013] [Accepted: 10/21/2013] [Indexed: 01/04/2023] Open
Abstract
H2O2 can cause oxidative damage associated with age-related diseases such as diabetes and cancer but is also used to initiate diverse responses, including increased antioxidant gene expression. Despite significant interest, H2O2-signaling mechanisms remain poorly understood. Here, we present a mechanism for the propagation of an H2O2 signal that is vital for the adaptation of the model yeast, Schizosaccharomyces pombe, to oxidative stress. Peroxiredoxins are abundant peroxidases with conserved antiaging and anticancer activities. Remarkably, we find that the only essential function for the thioredoxin peroxidase activity of the Prx Tpx1(hPrx1/2) in resistance to H2O2 is to inhibit a conserved thioredoxin family protein Txl1(hTxnl1/TRP32). Thioredoxins regulate many enzymes and signaling proteins. Thus, our discovery that a Prx amplifies an H2O2 signal by driving the oxidation of a thioredoxin-like protein has important implications, both for Prx function in oxidative stress resistance and for responses to H2O2. The thioredoxin-like protein Txl1 is oxidized in response to H2O2 The thioredoxin peroxidase activity of the Prx Tpx1 is required for oxidation of Txl1 The AP-1-like transcription factor Pap1 is an in vivo substrate for Txl1 Tpx1’s thioredoxin peroxidase activity provides H2O2 resistance by regulating Txl1
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Affiliation(s)
- Jonathon D Brown
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle NE2 4HH, Tyne and Wear, UK
| | - Alison M Day
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle NE2 4HH, Tyne and Wear, UK
| | - Sarah R Taylor
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle NE2 4HH, Tyne and Wear, UK
| | - Lewis E Tomalin
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle NE2 4HH, Tyne and Wear, UK
| | - Brian A Morgan
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle NE2 4HH, Tyne and Wear, UK.
| | - Elizabeth A Veal
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle NE2 4HH, Tyne and Wear, UK.
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16
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Penney M, Samejima I, Wilkinson CR, McInerny CJ, Mathiassen SG, Wallace M, Toda T, Hartmann-Petersen R, Gordon C. Fission yeast 26S proteasome mutants are multi-drug resistant due to stabilization of the Pap1 transcription factor. PLoS One 2012; 7:e50796. [PMID: 23209828 PMCID: PMC3507774 DOI: 10.1371/journal.pone.0050796] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 10/25/2012] [Indexed: 01/12/2023] Open
Abstract
Here we report the result of a genetic screen for mutants resistant to the microtubule poison methyl benzimidazol-2-yl carbamate (MBC) that were also temperature sensitive for growth. In total the isolated mutants were distributed in ten complementation groups. Cloning experiments revealed that most of the mutants were in essential genes encoding various 26S proteasome subunits. We found that the proteasome mutants are multi-drug resistant due to stabilization of the stress-activated transcription factor Pap1. We show that the ubiquitylation and ultimately the degradation of Pap1 depend on the Rhp6/Ubc2 E2 ubiquitin conjugating enzyme and the Ubr1 E3 ubiquitin-protein ligase. Accordingly, mutants lacking Rhp6 or Ubr1 display drug-resistant phenotypes.
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Affiliation(s)
- Mary Penney
- Medical Research Council, Human Genetics Unit, Western General Hospital, Edinburgh, United Kingdom
| | - Itaru Samejima
- Medical Research Council, Human Genetics Unit, Western General Hospital, Edinburgh, United Kingdom
| | - Caroline R. Wilkinson
- Cell Regulation Group, Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom
| | - Christopher J. McInerny
- Division of Molecular and Cellular Biology, School of Life Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Søs G. Mathiassen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Mairi Wallace
- Medical Research Council, Human Genetics Unit, Western General Hospital, Edinburgh, United Kingdom
| | - Takashi Toda
- Laboratory of Cell Regulation, Cancer Research UK, London Research Institute, Lincoln's Inn Fields Laboratories, London, United Kingdom
| | | | - Colin Gordon
- Medical Research Council, Human Genetics Unit, Western General Hospital, Edinburgh, United Kingdom
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17
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Kriegenburg F, Poulsen EG, Koch A, Krüger E, Hartmann-Petersen R. Redox control of the ubiquitin-proteasome system: from molecular mechanisms to functional significance. Antioxid Redox Signal 2011; 15:2265-99. [PMID: 21314436 DOI: 10.1089/ars.2010.3590] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In their natural environments, cells are regularly exposed to oxidizing conditions that may lead to protein misfolding. If such misfolded proteins are allowed to linger, they may form insoluble aggregates and pose a serious threat to the cell. Accumulation of misfolded, oxidatively damaged proteins is characteristic of many diseases and during aging. To counter the adverse effects of oxidative stress, cells can initiate an antioxidative response in an attempt to repair the damage, or rapidly channel the damaged proteins for degradation by the ubiquitin-proteasome system (UPS). Recent studies have shown that elements of the oxidative stress response and the UPS are linked on many levels. To manage the extra burden of misfolded proteins, the UPS is induced by oxidative stress, and special proteasome subtypes protect cells against oxidative damage. In addition, the proteasome is directly associated with a thioredoxin and other cofactors that may adjust the particle's response during an oxidative challenge. Here, we give an overview of the UPS and a detailed description of the degradation of oxidized proteins and of the crosstalk between oxidative stress and protein degradation in health and disease.
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Affiliation(s)
- Franziska Kriegenburg
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5,Copenhagen, Denmark
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