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Troussicot L, Vallet A, Molin M, Burmann BM, Schanda P. Disulfide-Bond-Induced Structural Frustration and Dynamic Disorder in a Peroxiredoxin from MAS NMR. J Am Chem Soc 2023; 145:10700-10711. [PMID: 37140345 DOI: 10.1021/jacs.3c01200] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Disulfide bond formation is fundamentally important for protein structure and constitutes a key mechanism by which cells regulate the intracellular oxidation state. Peroxiredoxins (PRDXs) eliminate reactive oxygen species such as hydrogen peroxide through a catalytic cycle of Cys oxidation and reduction. Additionally, upon Cys oxidation PRDXs undergo extensive conformational rearrangements that may underlie their presently structurally poorly defined functions as molecular chaperones. Rearrangements include high molecular-weight oligomerization, the dynamics of which are, however, poorly understood, as is the impact of disulfide bond formation on these properties. Here we show that formation of disulfide bonds along the catalytic cycle induces extensive μs time scale dynamics, as monitored by magic-angle spinning NMR of the 216 kDa-large Tsa1 decameric assembly and solution-NMR of a designed dimeric mutant. We ascribe the conformational dynamics to structural frustration, resulting from conflicts between the disulfide-constrained reduction of mobility and the desire to fulfill other favorable contacts.
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Affiliation(s)
- Laura Troussicot
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30 Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, SE-405 30 Göteborg, Sweden
- Institut de Biologie Structurale, Univ. Grenoble Alpes, CEA, CNRS, IBS, 71 Avenue des Martyrs, F-38044 Grenoble, France
- Institute of Science and Technology Austria, Am Campus 1, A-3400 Klosterneuburg, Austria
| | - Alicia Vallet
- Institut de Biologie Structurale, Univ. Grenoble Alpes, CEA, CNRS, IBS, 71 Avenue des Martyrs, F-38044 Grenoble, France
| | - Mikael Molin
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30 Göteborg, Sweden
- Department of Life Sciences, Chalmers University of Technology, SE-405 30 Göteborg, Sweden
| | - Björn M Burmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30 Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, SE-405 30 Göteborg, Sweden
| | - Paul Schanda
- Institute of Science and Technology Austria, Am Campus 1, A-3400 Klosterneuburg, Austria
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2
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Troussicot L, Burmann BM, Molin M. Structural determinants of multimerization and dissociation in 2-Cys peroxiredoxin chaperone function. Structure 2021; 29:640-654. [PMID: 33945778 DOI: 10.1016/j.str.2021.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/31/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022]
Abstract
Peroxiredoxins (PRDXs) are abundant peroxidases present in all kingdoms of life. Recently, they have been shown to also carry out additional roles as molecular chaperones. To address this emerging supplementary function, this review focuses on structural studies of 2-Cys PRDX systems exhibiting chaperone activity. We provide a detailed understanding of the current knowledge of structural determinants underlying the chaperone function of PRDXs. Specifically, we describe the mechanisms which may modulate their quaternary structure to facilitate interactions with client proteins and how they are coordinated with the functions of other molecular chaperones. Following an overview of PRDX molecular architecture, we outline structural details of the presently best-characterized peroxiredoxins exhibiting chaperone function and highlight common denominators. Finally, we discuss the remarkable structural similarities between 2-Cys PRDXs, small HSPs, and J-domain-independent Hsp40 holdases in terms of their functions and dynamic equilibria between low- and high-molecular-weight oligomers.
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Affiliation(s)
- Laura Troussicot
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Björn M Burmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden.
| | - Mikael Molin
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden; Department of Biology and Biological Engineering, Chalmers University of Technology, 405 30 Göteborg, Sweden.
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3
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Pechmann S. Programmed Trade-offs in Protein Folding Networks. Structure 2020; 28:1361-1375.e4. [PMID: 33053320 DOI: 10.1016/j.str.2020.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/25/2020] [Accepted: 09/23/2020] [Indexed: 12/14/2022]
Abstract
Molecular chaperones as specialized protein quality control enzymes form the core of cellular protein homeostasis. How chaperones selectively interact with their substrate proteins thus allocate their overall limited capacity remains poorly understood. Here, I present an integrated analysis of sequence and structural determinants that define interactions of protein domains as the basic protein folding unit with the Saccharomyces cerevisiae Hsp70 Ssb. Structural homologs of single-domain proteins that differentially interact with Ssb for de novo folding were found to systematically differ in complexity of their folding landscapes, selective use of nonoptimal codons, and presence of short discriminative sequences, thus highlighting pervasive trade-offs in chaperone-assisted protein folding landscapes. However, short discriminative sequences were found to contribute by far the strongest signal toward explaining Ssb interactions. This observation suggested that some chaperone interactions may be directly programmed in the amino acid sequences rather than responding to folding challenges, possibly for regulatory advantages.
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Affiliation(s)
- Sebastian Pechmann
- Département de biochimie, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC H3T 1J4, Canada.
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4
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Anschau V, Ferrer-Sueta G, Aleixo-Silva RL, Bannitz Fernandes R, Tairum CA, Tonoli CCC, Murakami MT, de Oliveira MA, Netto LES. Reduction of sulfenic acids by ascorbate in proteins, connecting thiol-dependent to alternative redox pathways. Free Radic Biol Med 2020; 156:207-216. [PMID: 32615144 DOI: 10.1016/j.freeradbiomed.2020.06.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/25/2020] [Accepted: 06/06/2020] [Indexed: 02/06/2023]
Abstract
Sulfenic acids are the primary product of thiol oxidation by hydrogen peroxide and other oxidants. Several aspects of sulfenic acid formation through thiol oxidation were established recently. In contrast, the reduction of sulfenic acids is still scarcely investigated. Here, we characterized the kinetics of the reduction of sulfenic acids by ascorbate in several proteins. Initially, we described the crystal structure of our model protein (Tsa2-C170S). There are other Tsa2 structures in distinct redox states in public databases and all of them are decamers, with the peroxidatic cysteine very accessible to reductants, convenient features to investigate kinetics. We determined that the reaction between Tsa2-C170S-Cys-SOH and ascorbate proceeded with a rate constant of 1.40 ± 0.08 × 103 M-1 s-1 through a competition assay developed here, employing 2,6-dichlorophenol-indophenol (DCPIP). A series of peroxiredoxin enzymes (Prx6 sub family) were also analyzed by this competition assay and we observed that the reduction of sulfenic acids by ascorbate was in the 0.4-2.2 × 103 M-1 s-1 range. We also evaluated the same reaction on glyceraldehyde 3-phosphate dehydrogenase and papain, as the reduction of their sulfenic acids by ascorbate were reported previously. Once again, the rate constants are in the 0.4-2.2 × 103 M-1 s-1 range. We also analyzed the reduction of Tsa2-C170S-SOH by ascorbate by a second, independent method, following hydrogen peroxide reduction through a specific electrode (ISO-HPO-2, World Precision Instruments) and employing a bi-substrate, steady state approach. The kcat/KMAsc was 7.4 ± 0.07 × 103 M-1 s-1, which was in the same order of magnitude as the value obtained by the DCPIP competition assay. In conclusion, our data indicates that reduction of sulfenic acid in various proteins proceed at moderate rate and probably this reaction is more relevant in biological systems where ascorbate concentrations are high.
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Affiliation(s)
- Valesca Anschau
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
| | - Gerardo Ferrer-Sueta
- Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de La República, Iguá 4225, Montevideo, 11400, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de La República, Montevideo, Uruguay
| | - Rogerio Luis Aleixo-Silva
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
| | - Renata Bannitz Fernandes
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
| | - Carlos A Tairum
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil
| | - Celisa Caldana Costa Tonoli
- Brazilian Biorenewables National Laboratory, National Center for Research in Energy and Materials, Campinas, Brazil
| | - Mario Tyago Murakami
- Brazilian Biorenewables National Laboratory, National Center for Research in Energy and Materials, Campinas, Brazil
| | | | - Luis Eduardo Soares Netto
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-090, São Paulo, Brazil.
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5
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Young D, Pedre B, Ezeriņa D, De Smet B, Lewandowska A, Tossounian MA, Bodra N, Huang J, Astolfi Rosado L, Van Breusegem F, Messens J. Protein Promiscuity in H 2O 2 Signaling. Antioxid Redox Signal 2019; 30:1285-1324. [PMID: 29635930 DOI: 10.1089/ars.2017.7013] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
SIGNIFICANCE Decrypting the cellular response to oxidative stress relies on a comprehensive understanding of the redox signaling pathways stimulated under oxidizing conditions. Redox signaling events can be divided into upstream sensing of oxidants, midstream redox signaling of protein function, and downstream transcriptional redox regulation. Recent Advances: A more and more accepted theory of hydrogen peroxide (H2O2) signaling is that of a thiol peroxidase redox relay, whereby protein thiols with low reactivity toward H2O2 are instead oxidized through an oxidative relay with thiol peroxidases. CRITICAL ISSUES These ultrareactive thiol peroxidases are the upstream redox sensors, which form the first cellular port of call for H2O2. Not all redox-regulated interactions between thiol peroxidases and cellular proteins involve a transfer of oxidative equivalents, and the nature of redox signaling is further complicated through promiscuous functions of redox-regulated "moonlighting" proteins, of which the precise cellular role under oxidative stress can frequently be obscured by "polygamous" interactions. An ultimate goal of redox signaling is to initiate a rapid response, and in contrast to prokaryotic oxidant-responsive transcription factors, mammalian systems have developed redox signaling pathways, which intersect both with kinase-dependent activation of transcription factors, as well as direct oxidative regulation of transcription factors through peroxiredoxin (Prx) redox relays. FUTURE DIRECTIONS We highlight that both transcriptional regulation and cell fate can be modulated either through oxidative regulation of kinase pathways, or through distinct redox-dependent associations involving either Prxs or redox-responsive moonlighting proteins with functional promiscuity. These protein associations form systems of crossregulatory networks with multiple nodes of potential oxidative regulation for H2O2-mediated signaling.
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Affiliation(s)
- David Young
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Brandan Pedre
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Daria Ezeriņa
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Barbara De Smet
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Aleksandra Lewandowska
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Maria-Armineh Tossounian
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Nandita Bodra
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Jingjing Huang
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Leonardo Astolfi Rosado
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Frank Van Breusegem
- 2 Brussels Center for Redox Biology, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Joris Messens
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
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6
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Nelson KJ, Perkins A, Van Swearingen AED, Hartman S, Brereton AE, Parsonage D, Salsbury FR, Karplus PA, Poole LB. Experimentally Dissecting the Origins of Peroxiredoxin Catalysis. Antioxid Redox Signal 2018; 28:521-536. [PMID: 28375740 PMCID: PMC5806077 DOI: 10.1089/ars.2016.6922] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
AIMS Peroxiredoxins (Prxs) are ubiquitous cysteine-based peroxidases involved in oxidant defense and signal transduction. Despite much study, the precise roles of conserved residues remain poorly defined. In this study, we carried out extensive functional and structural characterization of 10 variants of such residues in a model decameric bacterial Prx. RESULTS Three active site proximal mutations of Salmonella typhimurium AhpC, T43V, R119A, and E49Q, lowered catalytic efficiency with hydrogen peroxide by 4-5 orders of magnitude, but did not affect reactivity toward their reductant, AhpF. pKa values of the peroxidatic cysteine were also shifted up by 1-1.3 pH units for these and a decamer disruption mutant, T77I. Except for the decamer-stabilizing T77V, all mutations destabilized decamers in the reduced form. In the oxidized form, three mutants-T77V, T43A, and T43S-exhibited stabilized decamers and were more efficiently reduced by AhpF than wild-type AhpC. Crystal structures of most mutants were solved and many showed alterations in stability of the fully folded active site loop. INNOVATION This is the first study of Prx mutants to comprehensively assess the effects of mutations on catalytic activities, the active site cysteine pKa, and the protein structure and oligomeric status. CONCLUSION The Arg119 side chain must be properly situated for efficient catalysis, but for other debilitating variants, the functional defects could be explained by structural perturbations and/or associated decamer destabilization rather than direct effects. This underscores the importance of our comprehensive approach. A remarkable new finding was the preference of the reductant for decamers. Antioxid. Redox Signal. 28, 521-536.
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Affiliation(s)
- Kimberly J Nelson
- 1 Department of Biochemistry, Wake Forest School of Medicine , Winston-Salem, North Carolina.,2 Center for Redox Biology and Medicine, Wake Forest School of Medicine , Winston-Salem, North Carolina
| | - Arden Perkins
- 3 Department of Biochemistry and Biophysics, Oregon State University , Corvallis, Oregon
| | - Amanda E D Van Swearingen
- 1 Department of Biochemistry, Wake Forest School of Medicine , Winston-Salem, North Carolina.,2 Center for Redox Biology and Medicine, Wake Forest School of Medicine , Winston-Salem, North Carolina
| | - Steven Hartman
- 3 Department of Biochemistry and Biophysics, Oregon State University , Corvallis, Oregon
| | - Andrew E Brereton
- 3 Department of Biochemistry and Biophysics, Oregon State University , Corvallis, Oregon
| | - Derek Parsonage
- 1 Department of Biochemistry, Wake Forest School of Medicine , Winston-Salem, North Carolina.,2 Center for Redox Biology and Medicine, Wake Forest School of Medicine , Winston-Salem, North Carolina
| | - Freddie R Salsbury
- 2 Center for Redox Biology and Medicine, Wake Forest School of Medicine , Winston-Salem, North Carolina.,4 Department of Physics, Wake Forest University , Winston-Salem, North Carolina
| | - P Andrew Karplus
- 3 Department of Biochemistry and Biophysics, Oregon State University , Corvallis, Oregon
| | - Leslie B Poole
- 1 Department of Biochemistry, Wake Forest School of Medicine , Winston-Salem, North Carolina.,2 Center for Redox Biology and Medicine, Wake Forest School of Medicine , Winston-Salem, North Carolina
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7
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The Stress-Inducible Peroxidase TSA2 Underlies a Conditionally Beneficial Chromosomal Duplication in Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2017; 7:3177-3184. [PMID: 28743806 PMCID: PMC5592942 DOI: 10.1534/g3.117.300069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Although chromosomal duplications are often deleterious, in some cases they enhance cells’ abilities to tolerate specific genetic or environmental challenges. Identifying the genes that confer these conditionally beneficial effects to particular chromosomal duplications can improve our understanding of the genetic and molecular mechanisms that enable certain aneuploidies to persist in cell populations and contribute to disease and evolution. Here, we perform a screen for spontaneous mutations that improve the tolerance of haploid Saccharomyces cerevisiae to hydrogen peroxide. Chromosome IV duplication is the most frequent mutation, as well as the only change in chromosomal copy number seen in the screen. Using a genetic mapping strategy that involves systematically deleting segments of a duplicated chromosome, we show that the chromosome IV’s duplication effect is largely due to the generation of a second copy of the stress-inducible cytoplasmic thioredoxin peroxidase TSA2. Our findings add to a growing body of literature that shows the conditionally beneficial effects of chromosomal duplication are typically mediated by a small number of genes that enhance tolerance to specific stresses when their copy numbers are increased.
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Abstract
Peroxiredoxins (Prxs) are a large and conserved family of peroxidases that are considered to be the primary cellular guardians against oxidative stress in all living organisms. Prxs share a thioredoxin fold and contain a highly-reactive peroxidatic cysteine in a specialised active-site environment that is able to reduce their peroxide substrates. The minimal functional unit for Prxs are either monomers or dimers, but many dimers assemble into decameric rings. Ring structures can further form a variety of high molecular weight complexes. Many eukaryotic Prxs contain a conserved GGLG and C-terminal YF motif that confer sensitivity to elevated levels of peroxide, leading to hyperoxidation and inactivation. Inactive forms of Prxs can be re-reduced by the enzyme sulfiredoxin, in an ATP-dependent reaction. Cycles of hyperoxidation and reactivation are considered to play an integral role in a variety of H2O2-mediated cell signalling pathways in both stress and non-stress conditions. Prxs are also considered to exhibit chaperone-like properties when cells are under oxidative or thermal stress. The roles of various types of covalent modifications, e.g. acetylation and phosphorylation are also discussed. The ability of Prxs to assemble into ordered arrays such as nanotubes is currently being exploited in nanotechnology.
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Affiliation(s)
- Zhenbo Cao
- Institute of Molecular, Cell and Systems Biology, Davidson Building, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - John Gordon Lindsay
- Institute of Molecular, Cell and Systems Biology, Davidson Building, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
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Tairum CA, Santos MC, Breyer CA, Geyer RR, Nieves CJ, Portillo-Ledesma S, Ferrer-Sueta G, Toledo JC, Toyama MH, Augusto O, Netto LES, de Oliveira MA. Catalytic Thr or Ser Residue Modulates Structural Switches in 2-Cys Peroxiredoxin by Distinct Mechanisms. Sci Rep 2016; 6:33133. [PMID: 27629822 PMCID: PMC5024103 DOI: 10.1038/srep33133] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/22/2016] [Indexed: 12/27/2022] Open
Abstract
Typical 2-Cys Peroxiredoxins (2-Cys Prxs) reduce hydroperoxides with extraordinary rates due to an active site composed of a catalytic triad, containing a peroxidatic cysteine (CP), an Arg, and a Thr (or Ser). 2-Cys Prx are involved in processes such as cancer; neurodegeneration and host-pathogen interactions. During catalysis, 2-Cys Prxs switch between decamers and dimers. Analysis of 2-Cys Prx structures in the fully folded (but not locally unfolded) form revealed a highly conserved, non-conventional hydrogen bond (CH-π) between the catalytic triad Thr of a dimer with an aromatic residue of an adjacent dimer. In contrast, structures of 2-Cys Prxs with a Ser in place of the Thr do not display this CH-π bond. Chromatographic and structural data indicate that the Thr (but not Ser) destabilizes the decamer structure in the oxidized state probably through steric hindrance. As a general trend, mutations in a yeast 2-Cys Prx (Tsa1) favoring the dimeric state also displayed a decreased catalytic activity. Remarkably, yeast naturally contains Thr-Ser variants (Tsa1 and Tsa2, respectively) with distinct oligomeric stabilities in their disulfide states.
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Affiliation(s)
- Carlos A Tairum
- Instituto de Biociências, Campus do Litoral Paulista, Universidade Estadual Paulista Júlio de Mesquita Filho, São Vicente, São Paulo, 11330-900, Brazil
| | - Melina Cardoso Santos
- Instituto de Biociências, Campus do Litoral Paulista, Universidade Estadual Paulista Júlio de Mesquita Filho, São Vicente, São Paulo, 11330-900, Brazil
| | - Carlos A Breyer
- Instituto de Biociências, Campus do Litoral Paulista, Universidade Estadual Paulista Júlio de Mesquita Filho, São Vicente, São Paulo, 11330-900, Brazil
| | - R Ryan Geyer
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, 05508-090, Brazil
| | - Cecilia J Nieves
- Facultad de Ciencias - Universidad de la República - Montevideo, Uruguay
| | | | | | - José Carlos Toledo
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto - SP, 14040-901, Brazil
| | - Marcos H Toyama
- Instituto de Biociências, Campus do Litoral Paulista, Universidade Estadual Paulista Júlio de Mesquita Filho, São Vicente, São Paulo, 11330-900, Brazil
| | - Ohara Augusto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, 05508-090, Brazil
| | - Luis E S Netto
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-090, Brazil
| | - Marcos A de Oliveira
- Instituto de Biociências, Campus do Litoral Paulista, Universidade Estadual Paulista Júlio de Mesquita Filho, São Vicente, São Paulo, 11330-900, Brazil
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