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Holič R, Šťastný D, Griač P. Sec14 family of lipid transfer proteins in yeasts. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158990. [PMID: 34118432 DOI: 10.1016/j.bbalip.2021.158990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 11/25/2022]
Abstract
The hydrophobicity of lipids prevents their free movement across the cytoplasm. To achieve highly heterogeneous and precisely regulated lipid distribution in different cellular membranes, lipids are transported by lipid transfer proteins (LTPs) in addition to their transport by vesicles. Sec14 family is one of the most extensively studied groups of LTPs. Here we provide an overview of Sec14 family of LTPs in the most studied yeast Saccharomyces cerevisiae as well as in other selected non-Saccharomyces yeasts-Schizosaccharomyces pombe, Kluyveromyces lactis, Candida albicans, Candida glabrata, Cryptococcus neoformans, and Yarrowia lipolytica. Discussed are specificities of Sec14-domain LTPs in various yeasts, their mode of action, subcellular localization, and physiological function. In addition, quite few Sec14 family LTPs are target of antifungal drugs, serve as modifiers of drug resistance or influence virulence of pathologic yeasts. Thus, they represent an important object of study from the perspective of human health.
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Affiliation(s)
- Roman Holič
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Dominik Šťastný
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Peter Griač
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia.
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2
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Tripathi A, Martinez E, Obaidullah AJ, Lete MG, Lönnfors M, Khan D, Soni KG, Mousley CJ, Kellogg GE, Bankaitis VA. Functional diversification of the chemical landscapes of yeast Sec14-like phosphatidylinositol transfer protein lipid-binding cavities. J Biol Chem 2019; 294:19081-19098. [PMID: 31690622 DOI: 10.1074/jbc.ra119.011153] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/31/2019] [Indexed: 01/22/2023] Open
Abstract
Phosphatidylinositol-transfer proteins (PITPs) are key regulators of lipid signaling in eukaryotic cells. These proteins both potentiate the activities of phosphatidylinositol (PtdIns) 4-OH kinases and help channel production of specific pools of phosphatidylinositol 4-phosphate (PtdIns(4)P) dedicated to specific biological outcomes. In this manner, PITPs represent a major contributor to the mechanisms by which the biological outcomes of phosphoinositide are diversified. The two-ligand priming model proposes that the engine by which Sec14-like PITPs potentiate PtdIns kinase activities is a heterotypic lipid-exchange cycle where PtdIns is a common exchange substrate among the Sec14-like PITP family, but the second exchange ligand varies with the PITP. A major prediction of this model is that second-exchangeable ligand identity will vary from PITP to PITP. To address the heterogeneity in the second exchange ligand for Sec14-like PITPs, we used structural, computational, and biochemical approaches to probe the diversities of the lipid-binding cavity microenvironments of the yeast Sec14-like PITPs. The collective data report that yeast Sec14-like PITP lipid-binding pockets indeed define diverse chemical microenvironments that translate into differential ligand-binding specificities across this protein family.
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Affiliation(s)
- Ashutosh Tripathi
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114
| | - Elliott Martinez
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Ahmad J Obaidullah
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23298-0540
| | - Marta G Lete
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114
| | - Max Lönnfors
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114
| | - Danish Khan
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128
| | - Krishnakant G Soni
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114
| | - Carl J Mousley
- School of Biomedical Sciences, Curtin Health Innovation Research Institute (CHIRI), Faculty of Health Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Glen E Kellogg
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23298-0540
| | - Vytas A Bankaitis
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Sciences Center, College Station, Texas 77843-1114 .,Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128.,Department of Chemistry, Texas A&M University, College Station, Texas 77843-2128
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3
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Kiba A, Nakano M, Ohnishi K, Hikichi Y. The SEC14 phospholipid transfer protein regulates pathogen-associated molecular pattern-triggered immunity in Nicotiana benthamiana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 125:212-218. [PMID: 29475087 DOI: 10.1016/j.plaphy.2018.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/31/2018] [Accepted: 02/02/2018] [Indexed: 06/08/2023]
Abstract
We previously revealed that the SEC14 phospholipid transfer protein from Nicotiana benthamiana (NbSEC14) has a role in plant immune responses against phytopathogenic bacteria in a hypersensitive response-independent manner. To characterize the role of NbSEC14 on plant immunity, we analyzed the relationship between NbSEC14 and pathogen-associated molecular pattern-triggered immunity (PTI). NbSEC14-silenced plants exhibited down-regulated expression of PTI marker genes (NbAcre31 and NbPti5) after being inoculated with Pseudomonas syringae pv. tabaci. Additionally, we observed accelerated bacterial growth and inhibited expression of PTI marker genes in NbSEC14-silenced plants infected with the hrp-deficient P. syringae pv. tabaci mutant. We used Pseudomonas fluorescens and flg22 as PTI inducers to further examine the association between NbSEC14 and the induction of PTI. The expression of PTI marker genes was compromised in NbSEC14-silenced plants infiltrated with P. fluorescens and flg22. Meanwhile, a cell death-based PTI assay indicated NbSEC14 was required for PTI. Furthermore, callose deposition and disease resistance induced by flg22 were compromised in NbSEC14-silenced plants. These results suggest that NbSEC14 may help regulate the induction of PTI.
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Affiliation(s)
- Akinori Kiba
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture, Kochi University, Nankoku, Kochi 783-8502, Japan.
| | - Masahito Nakano
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture, Kochi University, Nankoku, Kochi 783-8502, Japan; Okayama Prefectural Technology Center for Agriculture, Forestry, and Fisheries, Nankoku, Kochi 783-8502, Japan
| | - Kouhei Ohnishi
- Research Institute of Molecular Genetics, Kochi University, Nankoku, Kochi 783-8502, Japan
| | - Yasufumi Hikichi
- Laboratory of Plant Pathology and Biotechnology, Faculty of Agriculture, Kochi University, Nankoku, Kochi 783-8502, Japan
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4
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Wang X, Shan X, Xue C, Wu Y, Su S, Li S, Liu H, Jiang Y, Zhang Y, Yuan Y. Isolation and functional characterization of a cold responsive phosphatidylinositol transfer-associated protein, ZmSEC14p, from maize (Zea may L.). PLANT CELL REPORTS 2016; 35:1671-86. [PMID: 27061906 DOI: 10.1007/s00299-016-1980-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 03/31/2016] [Indexed: 05/10/2023]
Abstract
A Sec14-like protein, ZmSEC14p , from maize was structurally analyzed and functionally tested. Overexpression of ZmSEC14p in transgenic Arabidopsis conferred tolerance to cold stress. Sec14-like proteins are involved in essential biological processes, such as phospholipid metabolism, signal transduction, membrane trafficking, and stress response. Here, we reported a phosphatidylinositol transfer-associated protein, ZmSEC14p (accession no. KT932998), isolated from a cold-tolerant maize inbred line using the cDNA-AFLP approach and RACE-PCR method. Full-length cDNA that consisted of a single open reading frame (ORF) encoded a putative polypeptide of 295 amino acids. The ZmSEC14p protein was mainly localized in the nucleus, and its transcript was induced by cold, salt stresses, and abscisic acid (ABA) treatment in maize leaves and roots. Overexpression of ZmSEC14p in transgenic Arabidopsis conferred tolerance to cold stress. This tolerance was primarily displayed by the increased germination rate, root length, plant survival rate, accumulation of proline, activities of antioxidant enzymes, and the reduction of oxidative damage by reactive oxygen species (ROS). ZmSEC14p overexpression regulated the expression of phosphoinositide-specific phospholipase C, which cleaves phosphatidylinositol 4,5-bisphosphate (PIP2) and generates second messengers (inositol 1,4,5-trisphosphate and 1,2-diacylglycerol) in the phosphoinositide signal transduction pathways. Moreover, up-regulation of some stress-responsive genes such as CBF3, COR6.6, and RD29B in transgenic plants under cold stress could be a possible mechanism for enhancing cold tolerance. Taken together, this study strongly suggests that ZmSEC14p plays an important role in plant tolerance to cold stress.
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Affiliation(s)
- Xiaoyu Wang
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Xiaohui Shan
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Chunmei Xue
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Ying Wu
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Shengzhong Su
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Shipeng Li
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Hongkui Liu
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Yuan Jiang
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Yanfei Zhang
- College of Plant Science, Jilin University, Changchun, 130062, China
| | - Yaping Yuan
- College of Plant Science, Jilin University, Changchun, 130062, China.
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Oh YM, Hong SK, Yeon JT, Cha MK, Kim IH. Interaction between Saccharomyces cerevisiae glutaredoxin 5 and SPT10 and their in vivo functions. Free Radic Biol Med 2012; 52:1519-30. [PMID: 22326886 DOI: 10.1016/j.freeradbiomed.2012.01.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 01/26/2012] [Accepted: 01/28/2012] [Indexed: 12/27/2022]
Abstract
Glutaredoxin 5 (Grx5) is a monothiol member of the Grx family that comprises two dithiol and three monothiol members. Using a yeast two-hybrid system, we isolated a Grx5-binding protein, SPT10, which has been previously suggested to act as a global transcriptional regulator of specific histone genes. We find that among the five members of the Grx family and two members of the thioredoxin (Trx) family (Trx1 and Trx2), Grx5 alone interacts with SPT10 via an intermolecular disulfide linkage between Cys60 of Grx5 and Cys385 of SPT10. To evaluate the physiological function of the Grx5/SPT10 interaction, we investigated the phenotypes of three null mutant strains (Grx5Δ, SPT10Δ, and Grx5ΔSPT10Δ). Taken together, the results show that all of these phenotypes are probably a consequence of the disruption of the interaction between Grx5 and SPT10. From this study, we suggest an interaction between Grx5 and SPT10 via intermolecular disulfide linkage and propose a model for a role of Grx5 in the regulation of protein expression under the control of SPT10.
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Affiliation(s)
- Young-Mee Oh
- Department of Biochemistry, Paichai University, Taejon 302-735, Republic of Korea
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Ueno S, Yasutake K, Tohyama D, Fujimori T, Ayusawa D, Fujii M. Systematic screen for genes involved in the regulation of oxidative stress in the nematode Caenorhabditis elegans. Biochem Biophys Res Commun 2012; 420:552-7. [DOI: 10.1016/j.bbrc.2012.03.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 03/07/2012] [Indexed: 01/29/2023]
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North M, Tandon VJ, Thomas R, Loguinov A, Gerlovina I, Hubbard AE, Zhang L, Smith MT, Vulpe CD. Genome-wide functional profiling reveals genes required for tolerance to benzene metabolites in yeast. PLoS One 2011; 6:e24205. [PMID: 21912624 PMCID: PMC3166172 DOI: 10.1371/journal.pone.0024205] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 08/06/2011] [Indexed: 11/18/2022] Open
Abstract
Benzene is a ubiquitous environmental contaminant and is widely used in industry. Exposure to benzene causes a number of serious health problems, including blood disorders and leukemia. Benzene undergoes complex metabolism in humans, making mechanistic determination of benzene toxicity difficult. We used a functional genomics approach to identify the genes that modulate the cellular toxicity of three of the phenolic metabolites of benzene, hydroquinone (HQ), catechol (CAT) and 1,2,4-benzenetriol (BT), in the model eukaryote Saccharomyces cerevisiae. Benzene metabolites generate oxidative and cytoskeletal stress, and tolerance requires correct regulation of iron homeostasis and the vacuolar ATPase. We have identified a conserved bZIP transcription factor, Yap3p, as important for a HQ-specific response pathway, as well as two genes that encode putative NAD(P)H:quinone oxidoreductases, PST2 and YCP4. Many of the yeast genes identified have human orthologs that may modulate human benzene toxicity in a similar manner and could play a role in benzene exposure-related disease.
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Affiliation(s)
- Matthew North
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California, United States of America
| | - Vickram J. Tandon
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California, United States of America
| | - Reuben Thomas
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Alex Loguinov
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California, United States of America
| | - Inna Gerlovina
- Division of Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Alan E. Hubbard
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
- Division of Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Luoping Zhang
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Martyn T. Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Chris D. Vulpe
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California, United States of America
- * E-mail:
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8
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Budanova EN, Bystrova MF. A search for protein-protein interactions of peroxiredoxin 6 with the yeast two-hybrid system. RUSS J GENET+ 2011. [DOI: 10.1134/s1022795408020038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Desfougères T, Ferreira T, Bergès T, Régnacq M. SFH2 regulates fatty acid synthase activity in the yeast Saccharomyces cerevisiae and is critical to prevent saturated fatty acid accumulation in response to haem and oleic acid depletion. Biochem J 2007; 409:299-309. [PMID: 17803462 DOI: 10.1042/bj20071028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The yeast Saccharomyces cerevisiae is a facultative anaerobic organism. Under anaerobiosis, sustained growth relies on the presence of exogenously supplied unsaturated fatty acids and ergosterol that yeast is unable to synthesize in the absence of oxygen or upon haem depletion. In the absence of exogenous supplementation with unsaturated fatty acid, a net accumulation of SFA (saturated fatty acid) is observed that induces significant modification of phospholipid profile [Ferreira, Régnacq, Alimardani, Moreau-Vauzelle and Bergès (2004) Biochem. J. 378, 899–908]. In the present paper, we focus on the role of SFH2/CSR1, a hypoxic gene related to SEC14 and its involvement in lipid metabolism upon haem depletion in the absence of oleic acid supplementation. We observed that inactivation of SFH2 results in enhanced accumulation of SFA and phospholipid metabolism alterations. It results in premature growth arrest and leads to an exacerbated sensitivity to exogenous SFA. This phenotype is suppressed in the presence of exogenous oleic acid, or by a controlled expression of FAS1, one of the two genes encoding FAS. We present several lines of evidence to suggest that Sfh2p and oleic acid regulate SFA synthase in yeast at different levels: whereas oleic acid acts on FAS2 at the transcriptional level, we show that Sfh2p inhibits fatty acid synthase activity in response to haem depletion.
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Affiliation(s)
- Thomas Desfougères
- Laboratoire de Génétique de la Levure CNRS-UMR6161, Université de Poitiers, 40 avenue du Recteur Pineau, 86022 Poitiers cedex, France
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Bankaitis VA, Vincent P, Merkulova M, Tyeryar K, Liu Y. Phosphatidylinositol transfer proteins and functional specification of lipid signaling pools. ACTA ACUST UNITED AC 2007; 47:27-40. [PMID: 17335879 PMCID: PMC2080876 DOI: 10.1016/j.advenzreg.2006.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Vytas A Bankaitis
- Department of Cell & Developmental Biology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7090, USA.
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Piattoni CV, Blancato VS, Miglietta H, Iglesias AA, Guerrero SA. On the occurrence of thioredoxin in Trypanosoma cruzi. Acta Trop 2006; 97:151-60. [PMID: 16310752 DOI: 10.1016/j.actatropica.2005.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Revised: 09/27/2005] [Accepted: 10/21/2005] [Indexed: 11/26/2022]
Abstract
The full coding sequence for thioredoxin from Trypanosoma cruzi (TcTRX) strain Tulahuen O has been cloned into the pRSETA vector. The protein was expressed in Escherichia coli with an N-terminal extension of six histidine residues for purification through metal ion chromatography. The biological activity of recombinant TcTRX was proved utilizing the insulin reduction assay. Amino acid sequence alignment indicates a high identity of TcTRX with thioredoxins from different sources. Immunocytochemistry assays showed that TcTRX is present in epimastigote forms of T. cruzi, thus, indicating that the gene is expressed in vivo, rather than being a pseudogene. The in vivo occurrence of TcTRX points out the necessity of considering this protein as a molecular component of the redox metabolism in trypanosomatids.
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Affiliation(s)
- Claudia V Piattoni
- Laboratorio de Bioquímica Microbiana, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Paraje El Pozo, CC 242, S 3000ZAA Santa Fe, Argentina
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12
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Hong SK, Cha MK, Kim IH. Specific protein interaction of human Pag with Omi/HtrA2 and the activation of the protease activity of Omi/HtrA2. Free Radic Biol Med 2006; 40:275-84. [PMID: 16413409 DOI: 10.1016/j.freeradbiomed.2005.08.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2005] [Revised: 08/01/2005] [Accepted: 08/16/2005] [Indexed: 11/24/2022]
Abstract
The human PAG gene product (hPag), one member of the TSA/AhpC family, is overexpressed by oxidative stress, which causes apoptosis. To investigate the apoptotic signal transduction mediated by hPag, hPag-binding protein was screened using the yeast two-hybrid system. Omi/HtrA2 was identified as the hPag-binding protein. Omi/HtrA2, a potent proapoptotic factor, is released from the mitochondria into the cytoplasm as the mature form showing serine protease activity during apoptosis in response to oxidative stress. We found that hPag was able to interact with the mature form of Omi/HtrA2, not with the precursor form of Omi/HtrA2. The binding of Omi/HtrA2 to hPag was shown to involve the PDZ-binding domain in Omi/HtrA2. Also, the carboxyl-terminal domain of hPag was shown to be critical for the protein interaction. Using the yeast two-hybrid system and in vitro binding assay, the reduced form of hPag was able to interact with Omi/HtrA2. Interestingly, the protease activity given by the mature form of Omi/HtrA2 was significantly activated by the binding to hPag. Taken together, these results suggest that the specific protein interaction may participate as a molecular switch in modulating cell death in response to oxidative stress.
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Affiliation(s)
- Seung-Keun Hong
- Department of Biochemistry, Paichai University, 439-6 Doma-2-Dong Seo-Gu, Taejon 302-735, Korea
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Munhoz DC, Netto LES. Cytosolic Thioredoxin Peroxidase I and II Are Important Defenses of Yeast against Organic Hydroperoxide Insult. J Biol Chem 2004; 279:35219-27. [PMID: 15210711 DOI: 10.1074/jbc.m313773200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cytosolic thioredoxin peroxidase II (cTPxII/Tsa2p) from Saccharomyces cerevisiae shares 86% identity with the relatively well characterized cytosolic thioredoxin peroxidase I (cTPxI/Tsa1p). In contrast to cTPxI protein, cTPxII is not abundant and is highly inducible by peroxides. Here, we describe a unique phenotype for DeltacTPxII strain; these cells were highly sensitive to tert-butylhydroperoxide (TBHP) but presented resistance to H(2)O(2) in fermentative and respiratory conditions. In contrast, DeltacTPxI strain was very sensitive to both TBHP and H(2)O(2), whatever the carbon source present in the media. These differences in the response of mutant cells to the different kinds of peroxide insult could not be attributed to enzymatic properties of cTPxI and cTPxII since the recombinant proteins showed similar in vitro efficiencies (K(cat) /K(m)) in the removals of both kinds of peroxide. This specific sensitivity of DeltacTPxII cells to TBHP could not be related to the expression pattern of TSA2 (cytosolic thioredoxin peroxidase II gene) either, since this gene is highly inducible by both H(2)O(2) and TBHP when cells were grown in different conditions. Finally, peroxide-removing assays were performed and showed that catalase activity increased significantly only in DeltacTPxII cells, which appear to be related with the resistance of this strain to H(2)O(2). Taken together, present data indicate that cTPxII and cTPxI are key components of the yeast defense system against organic peroxide insult. In regard to the stress induced by H(2)O(2), catalases (peroxisomal and/or cytosolic) and cTPxII seemed to cooperate with cTPxI in the defense of yeast against this oxidant.
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Wong CM, Siu KL, Jin DY. Peroxiredoxin-null Yeast Cells Are Hypersensitive to Oxidative Stress and Are Genomically Unstable. J Biol Chem 2004; 279:23207-13. [PMID: 15051715 DOI: 10.1074/jbc.m402095200] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peroxiredoxins are a family of abundant peroxidases found in all organisms. Although these antioxidant enzymes are thought to be critically involved in cellular defense and redox signaling, their exact physiological roles are largely unknown. In this study, we took a genetic approach to address the functions of peroxiredoxins in budding yeast. We generated and characterized a yeast mutant lacking all five peroxiredoxins. The quintuple peroxiredoxin-null mutant was still viable, though the growth rate was lower under normal aerobic conditions. Although peroxiredoxins are not essential for cell viability, peroxiredoxin-null yeast cells were more susceptible to oxidative and nitrosative stress. In the complete absence of peroxiredoxins, the expression of other antioxidant proteins including glutathione peroxidase and glutathione reductase was induced. In addition, the quintuple mutant was hypersensitive to glutathione depletion. Thus, the glutathione system might cooperate with other antioxidant enzymes to compensate for peroxiredoxin deficiency. Interestingly, the peroxiredoxinnull yeast cells displayed an increased rate of spontaneous mutations that conferred resistance to canavanine. This mutator phenotype was rescued by yeast peroxiredoxin Tsa1p, but not by its active-site mutant defective for peroxidase activity. Our findings suggest that the antioxidant function of peroxiredoxins is important for maintaining genome stability in eukaryotic cells.
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Affiliation(s)
- Chi-Ming Wong
- Department of Biochemistry, University of Hong Kong, Hong Kong, China
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