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Williams KE, Olsen DR. Gelatin expression from an engineered Saccharomyces cerevisiae CUP1 promoter in Pichia pastoris. Yeast 2021; 38:382-387. [PMID: 33580598 DOI: 10.1002/yea.3554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 11/12/2022] Open
Abstract
The methylotrophic yeast Pichia pastoris (reclassified as Komagataella phaffii) is a versatile protein expression system, yet many commonly used promoters have attributes undesirable for fermentation or its optimization. Hence, the copper-inducible CUP1 gene promoter from the related yeast Saccharomyces cerevisiae was used to express human gelatin. Multimerization of a potential copper response element in the CUP1 promoter, a S. cerevisiae Ace1p binding site, significantly increased gelatin expression. Expression was induced by copper in a dose-dependent fashion and was not dependent on cell density. Gelatin was additionally induced in standard copper-containing fermentation basal salts media. Removal of a S. cerevisiae heat shock factor (Hsf1p) binding site reduced copper-dependent gelatin induction suggesting that a similar protein may regulate this promoter in P. pastoris. This engineered copper inducible promoter expands the yeast recombinant protein production tool kit.
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Affiliation(s)
- Kim E Williams
- Collagen and Gelatin Molecular Biology, FibroGen, Inc., San Francisco, CA, USA
| | - David R Olsen
- Collagen and Gelatin Molecular Biology, FibroGen, Inc., San Francisco, CA, USA
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2
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Molecular characterization of Hsf1 as a master regulator of heat shock response in the thermotolerant methylotrophic yeast Ogataea parapolymorpha. J Microbiol 2021; 59:151-163. [PMID: 33527316 DOI: 10.1007/s12275-021-0646-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 10/22/2022]
Abstract
Ogataea parapolymorpha (Hansenula polymorpha DL-1) is a thermotolerant methylotrophic yeast with biotechnological applications. Here, O. parapolymorpha genes whose expression is induced in response to heat shock were identified by transcriptome analysis and shown to possess heat shock elements (HSEs) in their promoters. The function of O. parapolymorpha HSF1 encoding a putative heat shock transcription factor 1 (OpHsf1) was characterized in the context of heat stress response. Despite exhibiting low sequence identity (26%) to its Saccharomyces cerevisiae homolog, OpHsf1 harbors conserved domains including a DNA binding domain (DBD), domains involved in trimerization (TRI), transcriptional activation (AR1, AR2), transcriptional repression (CE2), and a C-terminal modulator (CTM) domain. OpHSF1 could complement the temperature sensitive (Ts) phenotype of a S. cerevisiae hsf1 mutant. An O. parapolymorpha strain with an H221R mutation in the DBD domain of OpHsf1 exhibited significantly retarded growth and a Ts phenotype. Intriguingly, the expression of heat-shock-protein-coding genes harboring HSEs was significantly decreased in the H221R mutant strain, even under non-stress conditions, indicating the importance of the DBD for the basal growth of O. parapolymorpha. Notably, even though the deletion of C-terminal domains (ΔCE2, ΔAR2, ΔCTM) of OpHsf1 destroyed complementation of the growth defect of the S. cerevisiae hsf1 strain, the C-terminal domains were shown to be dispensable in O. parapolymorpha. Overexpression of OpHsf1 in S. cerevisiae increased resistance to transient heat shock, supporting the idea that OpHsf1 could be useful in the development of heat-shock-resistant yeast host strains.
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Cadmium Uptake, MT Gene Activation and Structure of Large-Sized Multi-Domain Metallothioneins in the Terrestrial Door Snail Alinda biplicata (Gastropoda, Clausiliidae). Int J Mol Sci 2020; 21:ijms21051631. [PMID: 32120996 PMCID: PMC7084494 DOI: 10.3390/ijms21051631] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 02/06/2023] Open
Abstract
Terrestrial snails (Gastropoda) possess Cd-selective metallothioneins (CdMTs) that inactivate Cd2+ with high affinity. Most of these MTs are small Cysteine-rich proteins that bind 6 Cd2+ equivalents within two distinct metal-binding domains, with a binding stoichiometry of 3 Cd2+ ions per domain. Recently, unusually large, so-called multi-domain MTs (md-MTs) were discovered in the terrestrial door snail Alinda biplicata (A.b.). The aim of this study is to evaluate the ability of A.b. to cope with Cd stress and the potential involvement of md-MTs in its detoxification. Snails were exposed to increasing Cd concentrations, and Cd-tissue concentrations were quantified. The gene structure of two md-MTs (9md-MT and 10md-MT) was characterized, and the impact of Cd exposure on MT gene transcription was quantified via qRT PCR. A.b. efficiently accumulates Cd at moderately elevated concentrations in the feed, but avoids food uptake at excessively high Cd levels. The structure and expression of the long md-MT genes of A.b. were characterized. Although both genes are intronless, they are still transcribed, being significantly upregulated upon Cd exposure. Overall, our results contribute new knowledge regarding the metal handling of Alinda biplicata in particular, and the potential role of md-MTs in Cd detoxification of terrestrial snails, in general.
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Veri AO, Robbins N, Cowen LE. Regulation of the heat shock transcription factor Hsf1 in fungi: implications for temperature-dependent virulence traits. FEMS Yeast Res 2019; 18:4975774. [PMID: 29788061 DOI: 10.1093/femsyr/foy041] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/16/2018] [Indexed: 12/27/2022] Open
Abstract
The impact of fungal pathogens on human health is devastating. For fungi and other pathogens, a key determinant of virulence is the capacity to thrive at host temperatures, with elevated temperature in the form of fever as a ubiquitous host response to defend against infection. A prominent feature of cells experiencing heat stress is the increased expression of heat shock proteins (Hsps) that play pivotal roles in the refolding of misfolded proteins in order to restore cellular homeostasis. Transcriptional activation of this heat shock response is orchestrated by the essential heat shock transcription factor, Hsf1. Although the influence of Hsf1 on cellular stress responses has been studied for decades, many aspects of its regulation and function remain largely enigmatic. In this review, we highlight our current understanding of how Hsf1 is regulated and activated in the model yeast Saccharomyces cerevisiae, and highlight exciting recent discoveries related to its diverse functions under both basal and stress conditions. Given that thermal adaption is a fundamental requirement for growth and virulence in fungal pathogens, we also compare and contrast Hsf1 activation and function in other fungal species with an emphasis on its role as a critical regulator of virulence traits.
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Affiliation(s)
- Amanda O Veri
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
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5
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Morano KA, Thiele DJ. Heat shock factor function and regulation in response to cellular stress, growth, and differentiation signals. Gene Expr 2018; 7:271-82. [PMID: 10440228 PMCID: PMC6174667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Heat shock factors (HSF) activate the transcription of genes encoding products required for protein folding, processing, targeting, degradation, and function. Although HSFs have been extensively studied with respect to their role in thermotolerance and the activation of gene expression in response to environmental stress, the involvement of HSFs in response to stresses associated with cell growth and differentiation, and in response to normal physiological processes is becoming increasingly clear. In this work, we review recent advances toward understanding how cells transmit growth control and developmental signals, and interdigitate cellular physiology, to regulate HSF function.
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Affiliation(s)
- Kevin A. Morano
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-0606
| | - Dennis J. Thiele
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-0606
- Address correspondence to Dennis J. Thiele. Tel: (734) 763-5717; Fax: (734) 763-4581; E-mail:
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Physiological and Transcriptomic Analysis of a Chronologically Long-Lived Saccharomyces cerevisiae Strain Obtained by Evolutionary Engineering. Mol Biotechnol 2018; 60:468-484. [DOI: 10.1007/s12033-018-0087-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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7
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Guo SN, Zheng JL, Yuan SS, Zhu QL. Effects of heat and cadmium exposure on stress-related responses in the liver of female zebrafish: Heat increases cadmium toxicity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 618:1363-1370. [PMID: 29042086 DOI: 10.1016/j.scitotenv.2017.09.264] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/15/2017] [Accepted: 09/24/2017] [Indexed: 06/07/2023]
Abstract
In this study, female zebrafish (Danio rerio) were exposed to 26°C or 34°C, 0 or 197μg/L cadmium (Cd), singly or in combination for 7days. Multiple stress-related indicators were evaluated in the liver. Mortality, lipid peroxidation (LPO) and ultrastructural damage increased significantly by Cd exposure alone, and were not affected by heat alone. Interestingly, the combined exposure increased LPO, ultrastructural damage, and mortality compared with Cd exposure alone. The results indicated that elevated temperature increased Cd toxicity, which could be explained by several reasons. Firstly, Cd-exposed fish failed to activate the antioxidant defense system under heat stress. Secondly, expression levels of heat shock protein 70 (HSP70) were not significantly up-regulated by heat in Cd-exposed fish but increased by 117 times in Cd-free fish. Besides, hypermethylation of heat shock factor (HSF) binding motif in HSP70 promoter was observed during the combined exposure, indicating that simultaneous exposure may have partially suppressed the cytoprotective up-regulation of HSP70. Thirdly, heat induced an immunosuppressive effect in Cd-exposed fish, as reflected by the reduced mRNA and activity levels of nitric oxide synthase (iNOS) and interleukin-1β (IL-1β) expression levels. Finally, heat down-regulated Zir-, Irt-like protein 8 (ZIP8) and copper transporter 1 (CTR1) and up-regulated metallothioneins (MTs) in Cd-exposed fish, possibly suggesting Cu and Zn depletion and Cd accumulation. Hence, our data provide evidences that warmer temperatures can potentiate Cd toxicity, involved in the regulation of gene transcription, enzymatic activity, and DNA methylation. We found that heat indicators showed varied sensitivity between normal and Cd-exposed fish, emphasizing that the field metal pollution should be carefully considered when evaluating effects of climate change.
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Affiliation(s)
- Sai-Nan Guo
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Jia-Lang Zheng
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan 316022, PR China.
| | - Shuang-Shuang Yuan
- National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan 316022, PR China
| | - Qing-Ling Zhu
- Postgraduate Work Department, Zhejiang Ocean University, Zhoushan 316022, PR China
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The AMP-Activated Protein Kinase Homolog Snf1 Concerts Carbon Utilization, Conidia Production and the Biosynthesis of Secondary Metabolites in the Taxol-Producer Pestalotiopsis microspora. Genes (Basel) 2018; 9:genes9020059. [PMID: 29364863 PMCID: PMC5852555 DOI: 10.3390/genes9020059] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 01/03/2023] Open
Abstract
Highly conserved, the Snf1/AMPK is a central regulator of carbon metabolism and energy production in the eukaryotes. However, its function in filamentous fungi has not been well established. In this study, we reported functional characterization of Snf1/AMPK in the growth, development and secondary metabolism in the filamentous fungus Pestalotiopsis microspora. By deletion of the yeast SNF1 homolog, we found that it regulated the utilization of carbon sources, e.g., sucrose, demonstrating a conserved function of this kinase in filamentous fungus. Importantly, several novel functions of SNF1 were unraveled. For instance, the deletion strain displayed remarkable retardation in vegetative growth and pigmentation and produced a diminished number of conidia, even in the presence of the primary carbon source glucose. Deletion of the gene caused damages in the cell wall as shown by its hypersensitivities to Calcofluor white and Congo red, suggesting a critical role of Snf1 in maintaining cell wall integrity. Furthermore, the mutant strain Δsnf1 was hypersensitive to stress, e.g., osmotic pressure (1 M sorbitol), drug G418 and heat shock, though the mechanism remains to be illustrated. Significantly, disruption of the gene altered the production of secondary metabolites. By high-performance liquid chromatography (HPLC) profiling, we found that Δsnf1 barely produced secondary metabolites, e.g., the known product pestalotiollide B. This study suggests that Snf1 is a key regulator in filamentous fungus Pestalotiopsis microspora concerting carbon metabolism and the filamentous growth, conidiation, cell wall integrity, stress tolerance and the biosynthesis of secondary metabolites.
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Calatayud S, Garcia-Risco M, Rojas NS, Espinosa-Sánchez L, Artime S, Palacios Ò, Cañestro C, Albalat R. Metallothioneins of the urochordate Oikopleura dioica have Cys-rich tandem repeats, large size and cadmium-binding preference. Metallomics 2018; 10:1585-1594. [DOI: 10.1039/c8mt00177d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oikopleura dioica has the longest metallothionein described so far, made of repeats generated by a modular and step-wise evolution.
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Affiliation(s)
- Sara Calatayud
- Departament de Genètica
- Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio)
- Facultat de Biologia
- Universitat de Barcelona
- Barcelona
| | - Mario Garcia-Risco
- Departament de Química
- Facultat de Ciències
- Universitat Autònoma de Barcelona
- E-08193 Cerdanyola del Vallès
- Spain
| | - Natalia S. Rojas
- Departament de Genètica
- Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio)
- Facultat de Biologia
- Universitat de Barcelona
- Barcelona
| | - Lizethe Espinosa-Sánchez
- Departament de Genètica
- Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio)
- Facultat de Biologia
- Universitat de Barcelona
- Barcelona
| | - Sebastián Artime
- Departament de Genètica
- Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio)
- Facultat de Biologia
- Universitat de Barcelona
- Barcelona
| | - Òscar Palacios
- Departament de Química
- Facultat de Ciències
- Universitat Autònoma de Barcelona
- E-08193 Cerdanyola del Vallès
- Spain
| | - Cristian Cañestro
- Departament de Genètica
- Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio)
- Facultat de Biologia
- Universitat de Barcelona
- Barcelona
| | - Ricard Albalat
- Departament de Genètica
- Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio)
- Facultat de Biologia
- Universitat de Barcelona
- Barcelona
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10
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Adamczyk J, Deregowska A, Skoneczny M, Skoneczna A, Kwiatkowska A, Potocki L, Rawska E, Pabian S, Kaplan J, Lewinska A, Wnuk M. Adaptive response to chronic mild ethanol stress involves ROS, sirtuins and changes in chromosome dosage in wine yeasts. Oncotarget 2017; 7:29958-76. [PMID: 27074556 PMCID: PMC5058656 DOI: 10.18632/oncotarget.8673] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 04/03/2016] [Indexed: 12/23/2022] Open
Abstract
Industrial yeast strains of economic importance used in winemaking and beer production are genomically diverse and subjected to harsh environmental conditions during fermentation. In the present study, we investigated wine yeast adaptation to chronic mild alcohol stress when cells were cultured for 100 generations in the presence of non-cytotoxic ethanol concentration. Ethanol-induced reactive oxygen species (ROS) and superoxide signals promoted growth rate during passages that was accompanied by increased expression of sirtuin proteins, Sir1, Sir2 and Sir3, and DNA-binding transcription regulator Rap1. Genome-wide array-CGH analysis revealed that yeast genome was shaped during passages. The gains of chromosomes I, III and VI and significant changes in the gene copy number in nine functional gene categories involved in metabolic processes and stress responses were observed. Ethanol-mediated gains of YRF1 and CUP1 genes were the most accented. Ethanol also induced nucleolus fragmentation that confirms that nucleolus is a stress sensor in yeasts. Taken together, we postulate that wine yeasts of different origin may adapt to mild alcohol stress by shifts in intracellular redox state promoting growth capacity, upregulation of key regulators of longevity, namely sirtuins and changes in the dosage of genes involved in the telomere maintenance and ion detoxification.
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Affiliation(s)
- Jagoda Adamczyk
- Department of Genetics, University of Rzeszow, Rejtana, Rzeszow, Poland
| | - Anna Deregowska
- Department of Genetics, University of Rzeszow, Rejtana, Rzeszow, Poland.,Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Marek Skoneczny
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Adrianna Skoneczna
- Laboratory of Mutagenesis and DNA Repair, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | | | - Leszek Potocki
- Department of Genetics, University of Rzeszow, Rejtana, Rzeszow, Poland
| | - Ewa Rawska
- Department of Genetics, University of Rzeszow, Rejtana, Rzeszow, Poland
| | - Sylwia Pabian
- Department of Genetics, University of Rzeszow, Rejtana, Rzeszow, Poland
| | - Jakub Kaplan
- Department of Genetics, University of Rzeszow, Rejtana, Rzeszow, Poland
| | - Anna Lewinska
- Department of Biochemistry and Cell Biology, University of Rzeszow, Rzeszow, Poland
| | - Maciej Wnuk
- Department of Genetics, University of Rzeszow, Rejtana, Rzeszow, Poland
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11
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The Hsp70 homolog Ssb affects ribosome biogenesis via the TORC1-Sch9 signaling pathway. Nat Commun 2017; 8:937. [PMID: 29038496 PMCID: PMC5643326 DOI: 10.1038/s41467-017-00635-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 07/15/2017] [Indexed: 01/07/2023] Open
Abstract
The Hsp70 Ssb serves a dual role in de novo protein folding and ribosome biogenesis; however, the mechanism by which Ssb affects ribosome production is unclear. Here we establish that Ssb is causally linked to the regulation of ribosome biogenesis via the TORC1-Sch9 signaling pathway. Ssb is bound to Sch9 posttranslationally and required for the TORC1-dependent phosphorylation of Sch9 at T737. Also, Sch9 lacking phosphorylation at T737 displays significantly reduced kinase activity with respect to targets involved in the regulation of ribosome biogenesis. The absence of either Ssb or Sch9 causes enhanced ribosome aggregation. Particularly with respect to proper assembly of the small ribosomal subunit, SSB and SCH9 display strong positive genetic interaction. In combination, the data indicate that Ssb promotes ribosome biogenesis not only via cotranslational protein folding, but also posttranslationally via interaction with natively folded Sch9, facilitating access of the upstream kinase TORC1 to Sch9-T737.The yeast Hsp70 homolog Ssb is a chaperone that binds translating ribosomes where it is thought to function primarily by promoting nascent peptide folding. Here the authors find that the ribosome biogenesis defect associated with the loss of Ssb is attributable to a specific disruption in TORC1 signaling rather than defects in ribosomal protein folding.
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12
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Niederwanger M, Dvorak M, Schnegg R, Pedrini-Martha V, Bacher K, Bidoli M, Dallinger R. Challenging the Metallothionein (MT) Gene of Biomphalaria glabrata: Unexpected Response Patterns Due to Cadmium Exposure and Temperature Stress. Int J Mol Sci 2017; 18:E1747. [PMID: 28800079 PMCID: PMC5578137 DOI: 10.3390/ijms18081747] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/03/2017] [Accepted: 08/07/2017] [Indexed: 02/04/2023] Open
Abstract
Metallothioneins (MTs) are low-molecular-mass, cysteine-rich, metal binding proteins. In most animal species, they are involved in metal homeostasis and detoxification, and provide protection from oxidative stress. Gastropod MTs are highly diversified, exhibiting unique features and adaptations like metal specificity and multiplications of their metal binding domains. Here, we show that the MT gene of Biomphalaria glabrata, one of the largest MT genes identified so far, is composed in a unique way. The encoding for an MT protein has a three-domain structure and a C-terminal, Cys-rich extension. Using a bioinformatic approach involving structural and in silico analysis of putative transcription factor binding sites (TFBs), we found that this MT gene consists of five exons and four introns. It exhibits a regulatory promoter region containing three metal-responsive elements (MREs) and several TFBs with putative involvement in environmental stress response, and regulation of gene expression. Quantitative real-time polymerase chain reaction (qRT-PCR) data indicate that the MT gene is not inducible by cadmium (Cd) nor by temperature challenges (heat and cold), despite significant Cd uptake within the midgut gland and the high Cd tolerance of metal-exposed snails.
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Affiliation(s)
- Michael Niederwanger
- Institute of Zoology and Center of Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
| | - Martin Dvorak
- Institute of Zoology and Center of Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
| | - Raimund Schnegg
- Institute of Zoology and Center of Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
| | - Veronika Pedrini-Martha
- Institute of Zoology and Center of Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
| | - Katharina Bacher
- Institute of Zoology and Center of Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
| | - Massimo Bidoli
- Institute of Zoology and Center of Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
| | - Reinhard Dallinger
- Institute of Zoology and Center of Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
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Sappal R, Fast M, Purcell S, MacDonald N, Stevens D, Kibenge F, Siah A, Kamunde C. Copper and hypoxia modulate transcriptional and mitochondrial functional-biochemical responses in warm acclimated rainbow trout (Oncorhynchus mykiss). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 211:291-306. [PMID: 26774776 DOI: 10.1016/j.envpol.2015.11.050] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/26/2015] [Accepted: 11/27/2015] [Indexed: 06/05/2023]
Abstract
To survive in changing environments fish utilize a wide range of biological responses that require energy. We examined the effect of warm acclimation on the electron transport system (ETS) enzymes and transcriptional responses to hypoxia and copper (Cu) exposure in fish. Rainbow trout (Oncorhynchus mykiss) were acclimated to cold (11 °C; control) and warm (20 °C) temperatures for 3 weeks followed by exposure to Cu, hypoxia or both for 24 h. Activities of ETS enzyme complexes I-IV (CI-CIV) were measured in liver and gill mitochondria. Analyses of transcripts encoding for proteins involved in mitochondrial respiration (cytochrome c oxidase subunits 4-1 and 2: COX4-1 and COX4-2), metal detoxification/stress response (metallothioneins A and B: MT-A and MT-B) and energy sensing (AMP-activated protein kinase α1: AMPKα1) were done in liver mitochondria, and in whole liver and gill tissues by RT-qPCR. Warm acclimation inhibited activities of ETS enzymes while effects of Cu and hypoxia depended on the enzyme and thermal acclimation status. The genes encoding for COX4-1, COX4-2, MT-A, MT-B and AMPKα1 were strongly and tissue-dependently altered by warm acclimation. While Cu and hypoxia clearly increased MT-A and MT-B transcript levels in all tissues, their effects on COX4-1, COX4-2 and AMPKα1 mRNA levels were less pronounced. Importantly, warm acclimation differentially altered COX4-2/COX4-1 ratio in liver mitochondria and gill tissue. The three stressors showed both independent and joint actions on activities of ETS enzymes and transcription of genes involved in energy metabolism, stress response and metals homeostasis. Overall, we unveiled novel interactive effects that should not be overlooked in real world situations wherein fish normally encounter multiple stress factors.
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Affiliation(s)
- Ravinder Sappal
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada; Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Mark Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Sara Purcell
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Nicole MacDonald
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Don Stevens
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Fred Kibenge
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Ahmed Siah
- British Columbia Centre for Aquatic Health Sciences, 871A Island Highway, Campbell River, BC V9W 2C2, Canada
| | - Collins Kamunde
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada.
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Andrade-Linares DR, Lehmann A, Rillig MC. Microbial stress priming: a meta-analysis. Environ Microbiol 2016; 18:1277-88. [PMID: 26768991 DOI: 10.1111/1462-2920.13223] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 01/09/2016] [Indexed: 12/23/2022]
Abstract
Microbes have to cope with complex and dynamic environments, making it likely that anticipatory responses provide fitness benefits. Mild, previous stressors can prepare microbes (stress priming) to further and potentially damaging stressors (triggering). We here quantitatively summarize the findings from over 250 trials of 34 studies including bacteria and fungi, demonstrating that priming to stress has a beneficial impact on microbial survival. In fact, survival of primed microbes was about 10-fold higher compared with that in non-primed microbes. Categorical moderators related to microbial taxonomy and the kind of stress applied as priming or as triggering revealed significant differences of priming effect size among 14 different microbial species, 6 stress categories and stressor combination. We found that priming by osmotic, physiological and temperature stress had the highest positive effect sizes on microbial response. Cross-protection was evident for physiological, temperature and pH stresses. Microbes are better prepared against triggering by oxidative, temperature and osmotic stress. Our finding of an overall positive mean effect of priming regardless of the microbial system and particular stressor provides unprecedentedly strong evidence of the broad ecological significance of microbial stress priming. These results further suggest that stress priming may be an important factor in shaping microbial communities.
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Affiliation(s)
- Diana R Andrade-Linares
- Plant Ecology, Institut für Biologie, Freie Universität Berlin, Berlin, D-14195, Germany.,Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, D-14195, Germany
| | - Anika Lehmann
- Plant Ecology, Institut für Biologie, Freie Universität Berlin, Berlin, D-14195, Germany.,Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, D-14195, Germany
| | - Matthias C Rillig
- Plant Ecology, Institut für Biologie, Freie Universität Berlin, Berlin, D-14195, Germany.,Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, D-14195, Germany
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Rødkær SV, Pultz D, Brusch M, Bennetzen MV, Falkenby LG, Andersen JS, Færgeman NJ. Quantitative proteomics identifies unanticipated regulators of nitrogen- and glucose starvation. MOLECULAR BIOSYSTEMS 2015; 10:2176-88. [PMID: 24909858 DOI: 10.1039/c4mb00207e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular mechanisms underlying how cells sense, respond, and adapt to alterations in nutrient availability have been studied extensively during the past years. While most of these studies have focused on the linear connections between signaling components, it is increasingly being recognized that signaling pathways are interlinked in molecular circuits and networks such that any metabolic perturbation will induce signaling-wide ripple effects. In the present study, we have used quantitative mass spectrometry (MS) to examine how the yeast Saccharomyces cerevisiae responds to nitrogen- or glucose starvation. We identify nearly 1400 phosphorylation sites of which more than 500 are regulated in a temporal manner in response to glucose- or nitrogen starvation. By bioinformatics and network analyses, we have identified the cyclin-dependent kinase (CDK) inhibitor Sic1, the Hsp90 co-chaperone Cdc37, and the Hsp90 isoform Hsp82 to putatively mediate some of the starvation responses. Consistently, quantitative expression analyses showed that Sic1, Cdc37, and Hsp82 are required for normal expression of nutrient-responsive genes. Collectively, we therefore propose that Sic1, Cdc37, and Hsp82 may orchestrate parts of the cellular starvation response by regulating transcription factor- and kinase activities.
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Affiliation(s)
- Steven V Rødkær
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
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Wang Y, Zhang X, Zhou Q, Zhang X, Wei J. Comparative transcriptome analysis of the lichen-forming fungus Endocarpon pusillum elucidates its drought adaptation mechanisms. SCIENCE CHINA-LIFE SCIENCES 2014; 58:89-100. [PMID: 25480323 DOI: 10.1007/s11427-014-4760-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 06/06/2014] [Indexed: 01/16/2023]
Abstract
The lichen-forming fungus was isolated from the desert lichen Endocarpon pusillum that is extremely drought resistant. To understand the molecular mechanisms of drought resistance in the fungus, we employed RNA-seq and quantitative real-time PCR to compare and characterize the differentially expressed genes in pure culture at two different water levels and with that in desiccated lichen. The comparative transcriptome analysis indicated that a total of 1781 genes were differentially expressed between samples cultured under normal and PEG-induced drought stress conditions. Similar to those in drought resistance plants and non-lichenized fungi, the common drought-resistant mechanisms were differentially expressed in E. pusillum. However, the expression change of genes involved in osmotic regulation in E. pusillum is different, which might be the evidence for the feature of drought adaptation. Interestingly, different from other organisms, some genes involved in drought adaption mechanisms showed significantly different expression patterns between the presence and absence of drought stress in E. pusillum. The expression of 23 candidate stress responsive genes was further confirmed by quantitative real-time PCR using dehydrated E. pusillum lichen thalli. This study provides a valuable resource for future research on lichen-forming fungi and shall facilitate future functional studies of the specific genes related to drought resistance.
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Affiliation(s)
- YanYan Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
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Nussbaum I, Weindling E, Jubran R, Cohen A, Bar-Nun S. Deteriorated stress response in stationary-phase yeast: Sir2 and Yap1 are essential for Hsf1 activation by heat shock and oxidative stress, respectively. PLoS One 2014; 9:e111505. [PMID: 25356557 PMCID: PMC4214751 DOI: 10.1371/journal.pone.0111505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 10/02/2014] [Indexed: 11/19/2022] Open
Abstract
Stationary-phase cultures have been used as an important model of aging, a complex process involving multiple pathways and signaling networks. However, the molecular processes underlying stress response of non-dividing cells are poorly understood, although deteriorated stress response is one of the hallmarks of aging. The budding yeast Saccharomyces cerevisiae is a valuable model organism to study the genetics of aging, because yeast ages within days and are amenable to genetic manipulations. As a unicellular organism, yeast has evolved robust systems to respond to environmental challenges. This response is orchestrated largely by the conserved transcription factor Hsf1, which in S. cerevisiae regulates expression of multiple genes in response to diverse stresses. Here we demonstrate that Hsf1 response to heat shock and oxidative stress deteriorates during yeast transition from exponential growth to stationary-phase, whereas Hsf1 activation by glucose starvation is maintained. Overexpressing Hsf1 does not significantly improve heat shock response, indicating that Hsf1 dwindling is not the major cause for Hsf1 attenuated response in stationary-phase yeast. Rather, factors that participate in Hsf1 activation appear to be compromised. We uncover two factors, Yap1 and Sir2, which discretely function in Hsf1 activation by oxidative stress and heat shock. In Δyap1 mutant, Hsf1 does not respond to oxidative stress, while in Δsir2 mutant, Hsf1 does not respond to heat shock. Moreover, excess Sir2 mimics the heat shock response. This role of the NAD+-dependent Sir2 is supported by our finding that supplementing NAD+ precursors improves Hsf1 heat shock response in stationary-phase yeast, especially when combined with expression of excess Sir2. Finally, the combination of excess Hsf1, excess Sir2 and NAD+ precursors rejuvenates the heat shock response.
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Affiliation(s)
- Inbal Nussbaum
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Esther Weindling
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ritta Jubran
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Aviv Cohen
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Shoshana Bar-Nun
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Identification of fungal genes involved in the preinfection events between ectomycorrhizal association (Pisolithus tinctorius and Pinus massoniana). Mycol Prog 2013. [DOI: 10.1007/s11557-013-0899-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Characterization of heat shock protein 70 gene fromHaemonchus contortusand its expression and promoter analysis inCaenorhabditis elegans. Parasitology 2013; 140:683-94. [DOI: 10.1017/s0031182012002168] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SUMMARYHaemonchus contortusinfections in small ruminants are of major economic importance worldwide. Heat shock proteins (HSPs) are a family of molecular chaperones that play important roles in the process of invasion and survival of nematodes. Although HSP70 has been identified in several parasitic nematodes, little is known of its distribution and function inHaemonchus contortus. The aims of this study were to characterize HSP70 fromHaemonchus contortus(designed as Hc-hsp70), express Hc-hsp70 and analyse the promoter activity inCaenorhabditis elegans. Bioinformatic analysis revealed that the open reading frame of the Hc-hsp70 cDNA encodes a 646-amino acid peptide, which is highly conserved in comparison to HSP70 in other nematodes. Phylogenetic analysis indicated thatH. contortusis closely related toCaenorhabditis. The 5′-flanking region promoted green fluorescence protein (GFP) expression in the intestine in all larval stages and adult with 2 expression patterns inC. elegans. Expression of Hc-hsp70 mRNA transcripts inC. elegansincreased following 2, 4, 6 h of heat shock and peaked at 4 h. However, its expression induced down-regulation ofhsp-1ofC. elegans. These results suggest that theH. contortushsp70 might have a similar function to that ofC. elegans hsp-1.
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Asselman J, Glaholt SP, Smith Z, Smagghe G, Janssen CR, Colbourne JK, Shaw JR, De Schamphelaere KAC. Functional characterization of four metallothionein genes in Daphnia pulex exposed to environmental stressors. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 110-111:54-65. [PMID: 22266576 PMCID: PMC3967237 DOI: 10.1016/j.aquatox.2011.12.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Revised: 12/11/2011] [Accepted: 12/13/2011] [Indexed: 05/11/2023]
Abstract
We characterized the metallothionein genes (Mt1, Mt2, Mt3, and Mt4) in Daphnia pulex on both molecular and ecotoxicological level. We therefore conducted a bioinformatical analysis of the gene location and predicted protein sequence, and screened the upstream flanking region for regulatory elements. The number of these elements and their positions relative to the start codon varied strongly among the four genes and even among two gene duplicates (Mt1A and Mt1B), suggesting different roles of the four proteins in the organisms' response to stress. We subsequently conducted a chronic 16-day exposure of D. pulex to different environmental stressors (at sublethal levels causing approximately 50% reduction in reproduction). Based on prior knowledge, we exposed them to the metals Cd, Cu, and Ni, the moulting hormone hydroxyecdysone (20E), and the oxidative stressors cyanobacteria (Microcystis aeruginosa), and paraquat (Pq). We then compared mRNA expression levels of the four Mt genes under these stress conditions with control conditions in "The Chosen One" clone (TCO), for which the full genome was sequenced and annotated. All together, the mRNA expression results under the different stress regimes indicate that different Mt genes may play different and various roles in the response of D. pulex to stress and that some (but not all) of the differences among the four genes could be related to the pattern of regulatory elements in their upstream flanking region.
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Affiliation(s)
- J Asselman
- Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, Belgium.
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Paes HC, Mello-de-Sousa TM, Fernandes L, Teixeira MDM, Melo RDO, Derengowski LDS, Torres FAG, Felipe MSS. Characterisation of the heat shock factor of the human thermodimorphic pathogen Paracoccidioides lutzii. Fungal Genet Biol 2011; 48:947-55. [PMID: 21708278 DOI: 10.1016/j.fgb.2011.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Revised: 06/07/2011] [Accepted: 06/09/2011] [Indexed: 11/26/2022]
Abstract
Thermodimorphic fungi include most causative agents of systemic mycoses, but the molecular mechanisms that underlie their defining trait, i.e. the ability to shift between mould and yeast on temperature change alone, remain poorly understood. We hypothesised that the heat shock factor (Hsf), a protein that evolved to sense thermal stimuli quickly, might play a role in this process in addition to the known regulator Drk1 and the Ryp proteins. To test this hypothesis, we characterised the Hsf from the thermodimorph Paracoccidioides lutzii (formerly Paracoccidioides brasiliensis isolate 01). We show in the present work that PlHsf possesses regulatory domains that are exclusive of the Eurotiomycetidae family, suggesting evolutionary specialisation; that it can successfully rescue the otherwise lethal loss of the native protein of Saccharomyces cerevisiae; and that its DNA-binding domain is able to recognise regulatory elements from the promoters of both Drk1 and Ryp1. An in silico screening of all 1 kb sequences upstream of P. lutzii ORFs revealed that 7% of them possess a heat shock element. This is the first description of a heat shock factor in a thermodimorphic fungus.
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Affiliation(s)
- Hugo Costa Paes
- Departamento de Biologia Celular, Universidade de Brasília, 70910-900 Brasília, DF, Brazil
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Gupta RS, Ahnn J. Cadmium‐induced gene expression is regulated by MTF‐1, a key metal‐responsive transcription factor. ACTA ACUST UNITED AC 2010. [DOI: 10.1080/12265071.2003.9647702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Ronojoy Sen Gupta
- a Department of Life Science and Biotechnology , Jadavpur University , Calcutta , 700032 , India Phone: E-mail:
| | - Joohong Ahnn
- b Department of Life Science , Kwangju Institute of Science and Technology , Gwangju , 500–712 , Korea
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Stress induced cross-protection against environmental challenges on prokaryotic and eukaryotic microbes. World J Microbiol Biotechnol 2010; 27:1281-96. [PMID: 25187127 DOI: 10.1007/s11274-010-0584-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 09/20/2010] [Indexed: 02/07/2023]
Abstract
Prokaryotic and eukaryotic microbes thrive successfully in stressful environments such as high osmolarity, acidic or alkali, solar heat and u.v. radiation, nutrient starvation, oxidative stress, and several others. To live under these continuous stress conditions, these microbes must have mechanisms to protect their proteins, membranes, and nucleic acids, as well as other mechanisms that repair nucleic acids. The stress responses in bacteria are controlled by master regulators, which include alternative sigma factors, such as RpoS and RpoH. The sigma factor RpoS integrates multiple signals, such as the general stress response regulators and the sigma factor RpoH regulates the heat shock proteins. These response pathways extensively overlap and are induced to various extents by the same environmental stresses. In eukaryotes, two major pathways regulate the stress responses: stress proteins, termed heat shock proteins (HSP), which appear to be required only for growth during moderate stress, and stress response elements (STRE), which are induced by different stress conditions and these elements result in the acquisition of a tolerant state towards any stress condition. In this review, the mechanisms of stress resistance between prokaryotic and eukaryotic microbes will be described and compared.
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Peisker K, Chiabudini M, Rospert S. The ribosome-bound Hsp70 homolog Ssb of Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:662-72. [PMID: 20226819 DOI: 10.1016/j.bbamcr.2010.03.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 03/01/2010] [Accepted: 03/04/2010] [Indexed: 11/29/2022]
Abstract
The Hsp70 homolog Ssb directly binds to the ribosome and contacts a variety of newly synthesized polypeptide chains as soon as they emerge from the ribosomal exit tunnel. For this reason a general role of Ssb in the de novo folding of newly synthesized proteins is highly suggestive. However, for more than a decade client proteins which require Ssb for proper folding have remained elusive. It was therefore speculated that Ssb, despite its ability to interact with a large variety of nascent polypeptides, may assist the folding of only a small and specific subset. Alternatively, it has been suggested that Ssb's function may be limited to the protection of nascent polypeptides from aggregation until downstream chaperones take over and actively fold their substrates. There is also evidence that Ssb, in parallel to a classical chaperone function, is involved in the regulation of cellular signaling processes. Here we aim to summarize what is currently known about Ssb's multiple functions and what remains to be ascertained by future research.
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Affiliation(s)
- Kristin Peisker
- Department of Cell and Molecular Biology, Biomedicinskt Centrum BMC, Uppsala, Sweden
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Mutational analysis of human heat-shock transcription factor 1 reveals a regulatory role for oligomerization in DNA-binding specificity. Biochem J 2009; 424:253-61. [PMID: 19758120 DOI: 10.1042/bj20090922] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
HSF (heat-shock transcription factor) trimers bind to the HSE (heat-shock element) regulatory sequence of target genes and regulate gene expression. A typical HSE consists of at least three contiguous inverted repeats of the 5-bp sequence nGAAn. Yeast HSF is able to recognize discontinuous HSEs that contain gaps in the array of the nGAAn sequence; however, hHSF1 (human HSF1) fails to recognize such sites in vitro, in yeast and in HeLa cells. In the present study, we isolated suppressors of the temperature-sensitive growth defect of hHSF1-expressing yeast cells. Intragenic suppressors contained amino acid substitutions in the DNA-binding domain of hHSF1 that enabled hHSF1 to regulate the transcription of genes containing discontinuous HSEs. The substitutions facilitated hHSF1 oligomerization, suggesting that the DNA-binding domain is important for this conformational change. Furthermore, other oligomerization-prone derivatives of hHSF1 were capable of recognizing discontinuous HSEs. These results suggest that modulation of oligomerization is important for the HSE specificity of hHSF1 and imply that hHSF1 possesses the ability to bind to and regulate gene expression via various types of HSEs in diverse cellular processes.
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Deletion analysis of the promoter of Aspergillus oryzae gene encoding heat shock protein 30. J Biosci Bioeng 2009; 107:345-51. [PMID: 19332290 DOI: 10.1016/j.jbiosc.2008.11.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Accepted: 11/29/2008] [Indexed: 11/21/2022]
Abstract
In order to find a promoter that could be influenced by temperature shift, we explored and isolated an Aspergillus oryzae gene expressed at high temperatures (37-42 degrees C) by the cDNA subtraction method. Of the 96 cDNA clones isolated from the subtraction library, one cDNA clone showed 73% identity with Aspergillus nidulans heat shock protein 30 (hsp30). Based on this, we designated the isolated gene hsp30 of A. oryzae. A. oryzae hsp30 was weakly expressed at 30 degrees C, but strongly at 40 degrees C. We showed that the promoter of this hsp30 induced heterologous gene expression at high temperatures using beta-glucuronidase (GUS) gene as a reporter. Regarding elucidation of the region essential for heat shock response, we showed that the minimum length of the promoter region that was essential for heat shock response was located between -388 and -272 (+1 indicated the first position of the translation initiation codon) of the hsp30 promoter. This promoter region harbors several putative transcription factor binding sites, including heat shock elements (HSEs), a CCAAT box, and a TATA box. Furthermore, site-directed mutagenesis of this promoter revealed that HSE1 (aTTCgtcGAAacgcccaGAAa) and HSE2 (cGAAagTTCtcGACg), located between -342 and -272 of the hsp30 promoter, were its cis-acting elements for heat shock response.
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EGG MARGIT, HÖCKNER MARTINA, BRANDSTÄTTER ANITA, SCHULER DIETMAR, DALLINGER REINHARD. Structural and bioinformatic analysis of the Roman snail Cd-Metallothionein gene uncovers molecular adaptation towards plasticity in coping with multifarious environmental stress. Mol Ecol 2009; 18:2426-43. [DOI: 10.1111/j.1365-294x.2009.04191.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Singh U, Bongcam-Rudloff E, Westermark B. A DNA sequence directed mutual transcription regulation of HSF1 and NFIX involves novel heat sensitive protein interactions. PLoS One 2009; 4:e5050. [PMID: 19337383 PMCID: PMC2660424 DOI: 10.1371/journal.pone.0005050] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 03/05/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Though the Nuclear factor 1 family member NFIX has been strongly implicated in PDGFB-induced glioblastoma, its molecular mechanisms of action remain unknown. HSF1, a heat shock-related transcription factor is also a powerful modifier of carcinogenesis by several factors, including PDGFB. How HSF1 transcription is controlled has remained largely elusive. METHODOLOGY/PRINCIPAL FINDINGS By combining microarray expression profiling and a yeast-two-hybrid screen, we identified that NFIX and its interactions with CGGBP1 and HMGN1 regulate expression of HSF1. We found that CGGBP1 organizes a bifunctional transcriptional complex at small CGG repeats in the HSF1 promoter. Under chronic heat shock, NFIX uses CGGBP1 and HMGN1 to get recruited to this promoter and in turn affects their binding to DNA. Results show that the interactions of NFIX with CGGBP1 and HMGN1 in the soluble fraction are heat shock sensitive due to preferential localization of CGGBP1 to heterochromatin after heat shock. HSF1 in turn was found to bind to the NFIX promoter and repress its expression in a heat shock sensitive manner. CONCLUSIONS/SIGNIFICANCE NFIX and HSF1 exert a mutual transcriptional repressive effect on each other which requires CGG repeat in HSF1 promoter and HSF1 binding site in NFIX promoter. We unravel a unique mechanism of heat shock sensitive DNA sequence-directed reciprocal transcriptional regulation between NFIX and HSF1. Our findings provide new insights into mechanisms of transcription regulation under stress.
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Affiliation(s)
- Umashankar Singh
- Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden
- * E-mail: (US); (BW)
| | | | - Bengt Westermark
- Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden
- * E-mail: (US); (BW)
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Su X, Chu X, Dong Z. Identification of elevated transcripts in a Trichoderma reesei strain expressing a chimeric transcription activator using suppression subtractive hybridization. World J Microbiol Biotechnol 2009. [DOI: 10.1007/s11274-009-9993-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ivanina AV, Taylor C, Sokolova IM. Effects of elevated temperature and cadmium exposure on stress protein response in eastern oysters Crassostrea virginica (Gmelin). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2009; 91:245-254. [PMID: 19124164 DOI: 10.1016/j.aquatox.2008.11.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 11/14/2008] [Accepted: 11/18/2008] [Indexed: 05/27/2023]
Abstract
Stress proteins such as heat shock proteins (HSPs) and metallothioneins (MTs) play a key role in cellular protection against environmental stress. Marine ectotherms such as eastern oysters Crassostrea virginica are commonly exposed to multiple stressors including temperature and pollution by metals such as cadmium (Cd) in estuaries and coastal zones; however, the combined effects of these stressors on their cellular protection mechanisms are poorly understood. We acclimated C. virginica from populations adapted to different thermal regimes (Washington, North Carolina and Texas) at a common temperature of 12 degrees C, and analyzed their expression of MTs and HSPs (cytosolic HSP69, HSC72-77, HSP90 and mitochondrial HSP60) in response to the combined acute temperature stress and long-term Cd exposure. Overall, HSP and MT induction patterns were similar in oysters from the three studied geographically distant populations. HSP69 and MTs were significantly up-regulated by Cd and temperature stress implying their important role in cellular stress protection. In contrast, HSC72-77, HSP60 and HSP90 were not consistently induced by either acute heat or Cd exposure. The induction temperature for MTs was higher than for HSP69 (>28 degrees C vs. 20 degrees C, respectively), and MTs were more strongly induced by Cd than by temperature stress (to up to 38-94-fold compared by 3.5-7.5-fold, respectively) consistent with their predominant role in metal detoxification. Notably, heat stress did not result in an additional increase in metallothionein expression in Cd-exposed oysters suggesting a capacity limitation during the combined exposure to Cd and temperature stress. Levels of HSP69 and in some cases, HSC72-77 and HSP90 were lower in Cd-exposed oysters as compared to their control counterparts during heat stress indicating that simultaneous exposure to these two stressors may have partially suppressed the cytoprotective upregulation of molecular chaperones. These limitations of stress protein response may contribute to the reduced thermotolerance of oysters from metal-polluted environments.
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Affiliation(s)
- A V Ivanina
- Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, USA
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Guo L, Chen S, Liu K, Liu Y, Ni L, Zhang K, Zhang L. Isolation of heat shock factor HsfA1a-binding sites in vivo revealed variations of heat shock elements in Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2008; 49:1306-1315. [PMID: 18641404 DOI: 10.1093/pcp/pcn105] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The information about DNA-binding sites of regulatory protein is important to understanding the regulatory network of DNA-protein interactions in the genome. In this report we integrated chromatin immunoprecipitation with DNA cloning to isolate genomic sites bound in vivo by heat shock factor HsfA1a in Arabidopsis thaliana. Plantlets were subjected to formaldehyde crosslinking, followed by immunoprecipitation of chromatin. The immunoprecipitated DNA was amplified by PCR and cloned. From a library enriched in putative HsfA1a-binding sites, 21 different genomic fragments were identified (65-332 bp). Six fragments contained known HsfA1a-binding motif (perfect heat shock element). Six fragments contained novel HsfA1a-binding motifs: (1) gap-type, (2) TTC-rich-type, (3) stress responsive element (STRE). Representatives of each were verified by in vitro electrophoretic mobility shift assay. About 81% of the isolated fragments contained the HsfA1a-binding motifs, and/or could be bound by HsfA1a, demonstrating that the method is efficient in the isolation of genomic binding sites of a regulatory protein. The nearest downstream genes to the HsfA1a-binding fragments, which were considered as potential HsfA1a target genes, include a set of classical heat shock protein genes: Hsp17.4, Hsp18.2, Hsp21, Hsp81-1, Hsp101, and several novel genes encoding a non-race specific disease resistance protein and a transmembrane CLPTM1 family protein.
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Affiliation(s)
- Lihong Guo
- Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming 650091, China
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Klockow C, Stahl F, Scheper T, Hitzmann B. Induction of Stress Genes inSaccharomyces cerevisiaeduring Starvation. Eng Life Sci 2008. [DOI: 10.1002/elsc.200700036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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34
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Gibson BR, Lawrence SJ, Boulton CA, Box WG, Graham NS, Linforth RS, Smart KA. The oxidative stress response of a lager brewing yeast strain during industrial propagation and fermentation. FEMS Yeast Res 2008; 8:574-85. [DOI: 10.1111/j.1567-1364.2008.00371.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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35
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The role of Sse1 in the de novo formation and variant determination of the [PSI+] prion. Genetics 2008; 177:1583-93. [PMID: 18039878 DOI: 10.1534/genetics.107.077982] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Yeast prions are a group of non-Mendelian genetic elements transmitted as altered and self-propagating conformations. Extensive studies in the last decade have provided valuable information on the mechanisms responsible for yeast prion propagation. How yeast prions are formed de novo and what cellular factors are required for determining prion "strains" or variants--a single polypeptide capable of existing in multiple conformations to result in distinct heritable phenotypes--continue to defy our understanding. We report here that Sse1, the yeast ortholog of the mammalian heat-shock protein 110 (Hsp110) and a nucleotide exchange factor for Hsp70 proteins, plays an important role in regulating [PSI+] de novo formation and variant determination. Overproduction of the Sse1 chaperone dramatically enhanced [PSI+] formation whereas deletion of SSE1 severely inhibited it. Only an unstable weak [PSI+] variant was formed in SSE1 disrupted cells whereas [PSI+] variants ranging from very strong to very weak were formed in isogenic wild-type cells under identical conditions. Thus, Sse1 is essential for the generation of multiple [PSI+] variants. Mutational analysis further demonstrated that the physical association of Sse1 with Hsp70 but not the ATP hydrolysis activity of Sse1 is required for the formation of multiple [PSI+] variants. Our findings establish a novel role for Sse1 in [PSI+] de novo formation and variant determination, implying that the mammalian Hsp110 may likewise be involved in the etiology of protein-folding diseases.
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36
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Bergero R, Lanfranco L, Ghignone S, Bonfante P. Enhanced activity of the GmarMT1 promoter from the mycorrhizal fungus Gigaspora margarita at limited carbon supply. Fungal Genet Biol 2007; 44:877-85. [PMID: 17482490 DOI: 10.1016/j.fgb.2007.01.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 01/18/2007] [Accepted: 01/22/2007] [Indexed: 10/23/2022]
Abstract
Metallothioneins are low molecular weight polypeptides, present in most eukaryotic phyla, with role in metal homeostasis and detoxification. We previously reported the identification and the characterization of a metallothionein gene (GmarMT1) from the arbuscular mycorrhizal fungus Gigaspora margarita. Here, we have used real-time quantitative RT-PCR to show that GmarMT1 expression was turned off during the symbiotic fungal growth in the hexose-rich mycorrhizal apoplast, whereas transcripts were abundant during all other fungal growth stages, when products of lipid breakdown and the glyoxylate cycle feed carbohydrate-consuming pathways. In support of a nutritional regulation of GmarMT1 expression, we show that transcriptional activity of GmarMT1 promoter in yeast was strongly induced by glucose starvation (up to 20 times the basal level). We speculate that GmarMT1-encoded protein, with its proved metal binding ability, could regulate the homeostasis of zinc, a fundamental cofactor involved in C metabolism regulation and glucose repression.
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Affiliation(s)
- Roberta Bergero
- Crop and Soil Research Group, Scottish Agricultural College, King's Buildings, West Mains Road, Edinburgh, EH9 3JG, UK.
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Anckar J, Sistonen L. Heat Shock Factor 1 as a Coordinator of Stress and Developmental Pathways. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 594:78-88. [PMID: 17205677 DOI: 10.1007/978-0-387-39975-1_8] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The transition from normal growth conditions to stressful conditions is accompanied by a robust upregulation of heat shock proteins, which dampen the cytotoxicity caused by misfolded and denatured proteins. The most prominent part of this transition occurs on the transcriptional level. In mammals, protein-damaging stress leads to the activation of heat shock factor 1 (HSF1), which binds to upstream regulatory sequences in the promoters of heat shock genes. The activation of HSF1 proceeds through a multi-step pathway, involving a monomer-to-trimer transition, nuclear accumulation and extensive posttranslational modifications. In addition to its established role as the main regulator of heat shock genes, new data link HSF 1 to developmental pathways. In this chapter, we examine the established stress-related functions and prospect the intriguing role of HSF 1 as a developmental coordinator.
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Affiliation(s)
- Julius Anckar
- Department of Biology, Abo Akademi University, P.O. Box 123 FI-20521 Turku, Finland
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38
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Hong SP, Carlson M. Regulation of snf1 protein kinase in response to environmental stress. J Biol Chem 2007; 282:16838-45. [PMID: 17438333 DOI: 10.1074/jbc.m700146200] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The Saccharomyces cerevisiae Snf1 protein kinase, a member of the Snf1/AMPK (AMP-activated protein kinase) family, has important roles in metabolic control, particularly in response to nutrient stress. Here we have addressed the role of Snf1 in responses to other environmental stresses. Exposure of cells to sodium ion stress, alkaline pH, or oxidative stress caused an increase in Snf1 catalytic activity and phosphorylation of Thr-210 in the activation loop, whereas treatment with sorbitol or heat shock did not. Inhibition of respiratory metabolism by addition of antimycin A to cells also increased Snf1 activity. Analysis of mutants indicated that the kinases Sak1, Tos3, and Elm1, which activate Snf1 in response to glucose limitation, are also required under other stress conditions. Each kinase sufficed for activation in response to stress, but Sak1 had the major role. In sak1Delta tos3Delta elm1Delta cells expressing mammalian Ca(2+)/calmodulin-dependent protein kinase kinase alpha, Snf1 was activated by both sodium ion and alkaline stress, suggesting that stress signals regulate Snf1 activity by a mechanism that is independent of the upstream kinase. Finally, we showed that Snf1 protein kinase is regulated differently during adaptation of cells to NaCl and alkaline pH with respect to both temporal regulation of activation and subcellular localization. Snf1 protein kinase becomes enriched in the nucleus in response to alkaline pH but not salt stress. Such differences could contribute to specificity of the stress responses.
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Affiliation(s)
- Seung-Pyo Hong
- Department of Genetics and Development, Columbia University, New York, New York 10032, USA
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39
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Hashikawa N, Yamamoto N, Sakurai H. Different Mechanisms Are Involved in the Transcriptional Activation by Yeast Heat Shock Transcription Factor through Two Different Types of Heat Shock Elements. J Biol Chem 2007; 282:10333-40. [PMID: 17289668 DOI: 10.1074/jbc.m609708200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The hydrophobic repeat is a conserved structural motif of eukaryotic heat shock transcription factor (HSF) that enables HSF to form a homotrimer. Homotrimeric HSF binds to heat shock elements (HSEs) consisting of three inverted repeats of the sequence nGAAn. Sequences consisting of four or more nGAAn units are bound cooperatively by two HSF trimers. We show that in Saccharomyces cerevisiae cells oligomerization-defective Hsf1 is not able to bind HSEs with three units and is not extensively phosphorylated in response to stress; it is therefore unable to activate genes containing this type of HSE. Several lines of evidence indicate that oligomerization is a prerequisite for stress-induced hyperphosphorylation of Hsf1. In contrast, oligomerization and hyperphosphorylation are not necessary for gene activation via HSEs with four units. Intragenic suppressor screening of oligomerization-defective hsf1 showed that an interface between adjacent DNA-binding domains is important for the binding of Hsf1 to the HSE. We suggest that Saccharomyces cerevisiae HSEs with different structures are regulated differently; HSEs with three units require Hsf1 to be both oligomerized and hyperphosphorylated, whereas HSEs with four or more units do not require either.
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Affiliation(s)
- Naoya Hashikawa
- Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan
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40
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Sakurai H, Takemori Y. Interaction between heat shock transcription factors (HSFs) and divergent binding sequences: binding specificities of yeast HSFs and human HSF1. J Biol Chem 2007; 282:13334-41. [PMID: 17347150 DOI: 10.1074/jbc.m611801200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The target genes of the heat shock transcription factor (HSF) contain a cis-acting sequence, the heat shock element (HSE), which consists of multiple inverted repeats of the sequence 5'-nGAAn-3'. Using data acquired in this and a previous study, we have identified the HSEs in 59 of 62 target genes of Saccharomyces cerevisiae Hsf1. The Hsf1 protein recognizes continuous and discontinuous repeats of the nGAAn unit; the nucleotide sequences and configuration of the units diverge slightly among functional HSEs. When Schizosaccharomyces pombe HSF was expressed in S. cerevisiae cells, heat shock induced S. pombe HSF to bind to various HSE types, which properly activated transcription from almost all target genes, suggesting that the S. pombe genome also contains divergent HSEs. Human HSF1 induced the heat shock response via HSEs with continuous units in S. cerevisiae cells but failed to do so via HSEs with discontinuous units. Binding of human HSF1 to the discontinuous type of HSE was observed in vitro but was significantly inhibited in vivo. These results show that human HSF1 recognizes HSEs in a slightly different way than yeast HSFs and suggest that the configuration of the unit is an important determinant for HSF-HSE interactions.
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Affiliation(s)
- Hiroshi Sakurai
- Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
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41
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Yamamoto A, Sakurai H. The DNA-binding domain of yeast Hsf1 regulates both DNA-binding and transcriptional activities. Biochem Biophys Res Commun 2006; 346:1324-9. [PMID: 16806072 DOI: 10.1016/j.bbrc.2006.06.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Accepted: 06/12/2006] [Indexed: 11/26/2022]
Abstract
The heat shock transcription factor (HSF) is a key regulator of the heat shock response. In Saccharomyces cerevisiae, the transcription activating ability of Hsf1 is repressed by its DNA-binding domain, but the detailed mechanism by which the inhibitory function is relieved in response to stress remains unknown. In this study, we isolated and characterized three hsf1 mutants with temperature-sensitive mutations in the DNA-binding domain. Two mutations inhibited DNA-binding activity, leading to decreased expression of target genes. The third mutation caused transcriptional defects without affecting DNA binding, and its suppressor mutation was located in a region important for sensing heat shock. These results indicate that the DNA-binding domain regulates both the DNA-binding and transcriptional activities of Hsf1, and suggest that these functions are located within discrete regions of the DNA-binding domain.
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Affiliation(s)
- Ayako Yamamoto
- Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan
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42
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Hashikawa N, Mizukami Y, Imazu H, Sakurai H. Mutated Yeast Heat Shock Transcription Factor Activates Transcription Independently of Hyperphosphorylation. J Biol Chem 2006; 281:3936-42. [PMID: 16361698 DOI: 10.1074/jbc.m510827200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The homotrimeric heat shock transcription factor (HSF) binds to the heat shock element of target genes and regulates transcription in response to various stresses. The Hsf1 protein of Saccharomyces cerevisiae is extensively phosphorylated upon heat shock; a modification that is under positive regulation by its C-terminal regulatory domain (CTM). Hyperphosphorylation has been implicated in gene-specific transcriptional activation. Here, we surveyed genes whose heat shock response is reduced by a CTM mutation. The CTM is indispensable for transcription via heat shock elements bound by a single Hsf1 trimer but is dispensable for transcription via heat shock elements bound by Hsf1 trimers in a cooperative manner. Intragenic mutations located within or near the wing region of the winged helix-turn-helix DNA-binding domain suppress the temperature-sensitive growth phenotype associated with the CTM mutation and enable Hsf1 to activate transcription independently of hyperphosphorylation. Deletion of the wing partially restores the transcriptional defects of the unphosphorylated Hsf1. These results demonstrate a functional link between hyperphosphorylation and the wing region and suggest that this modification is involved in a conformational change of a single Hsf1 trimer to an active form.
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Affiliation(s)
- Naoya Hashikawa
- Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, Ishikawa, Japan
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43
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Mizoguchi H, Hara S. Effect of overexpression of LAS17 on stress tolerance and the stability of extrachromosomal DNA in Saccharomyces cerevisiae. J Biosci Bioeng 2005; 91:33-9. [PMID: 16232942 DOI: 10.1263/jbb.91.33] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2000] [Accepted: 10/13/2000] [Indexed: 11/17/2022]
Abstract
The effects of the overexpression of LAS17/BEE1, which encodes a yeast protein exhibiting sequence homology to the Wiscott-Aldrich syndrome protein, on the cell growth of Saccharomyces cerevisiae were examined. Sake yeast strain UT-1 grows at a faster rate as a result of the overexpression of LAS17 than control cultures under various stresses such as high temperature, high ethanol concentration, and oxidative stress, and the tolerance to these stresses was increased compared with the control. Moreover, a high cell survival rate was attained with overexpression of LAS17, when cells in the stationary phase of the growth cycle were subjected to heat killing (48 degrees C) or ethanol killing (20% v/v). In addition, the rate of induction of rho- was markedly reduced by overexpression of LAS17 when serine, tyrosine, and aspartic acid were used as N sources and the yeast was cultured at 35 degrees C, while rho- strains in control cultures were induced at a high frequency. After the incubation of cells harboring a multicopy vector in YPD or synthetic complete medium, almost all of the cells inherited the vector at about 15 copies per cell as a result of the overexpression of LAS17, whereas the cells harboring the control vector accounted for only 15% of the total number of cells. These results suggest that Las17p might be a multifunctional protein involved in cell growth regulation, extrachromosomal DNA transportation and stress responses.
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Affiliation(s)
- H Mizoguchi
- General Research Laboratory of Kiku-Masamune Sake Brewing Co. Ltd., 1-8-6 Uozaki-nishimachi, Higashinada-ku, Kobe 658-0026, Japan.
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44
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Vydra N, Malusecka E, Jarzab M, Lisowska K, Glowala-Kosinska M, Benedyk K, Widlak P, Krawczyk Z, Widlak W. Spermatocyte-specific expression of constitutively active heat shock factor 1 induces HSP70i-resistant apoptosis in male germ cells. Cell Death Differ 2005; 13:212-22. [PMID: 16151457 DOI: 10.1038/sj.cdd.4401758] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Spermatocytes, the most sensitive male germ cells to heat-induced apoptosis, do not respond to hyperthermia by inducing heat shock proteins (HSPs), including HSP70i, which has been previously shown to confer resistance to apoptosis in somatic cells. To dissect the mechanism of heat-induced apoptosis and to determine if we could protect spermatocytes by expressing HSP70i, we engineered transgenic mice that express in spermatocytes constitutively active heat shock transcription factor (HSF)1. Such HSF1 expression did not lead to transcription of inducible Hsp70 genes, but instead induced caspase-dependent apoptosis that mimicked heat shock-induced death of spermatogenic cells. Both mitochondria-dependent and death receptor-dependent pathways appear to be involved in such HSF1-induced apoptosis: the levels of Bcl-2 family proteins became increased, p53 protein accumulated and expression levels of caspase-8 and death-receptor-interacting proteins (including Fas-associated death domain protein and TNF receptor associated death domain protein) became elevated. Surprisingly, the constitutive spermatocyte-specific expression of HSP70i in double-transgenic males did not protect against such HSF1-induced apoptosis.
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Affiliation(s)
- N Vydra
- Department of Tumor Biology, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, 44-101 Gliwice, Poland
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45
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Yamamoto A, Mizukami Y, Sakurai H. Identification of a novel class of target genes and a novel type of binding sequence of heat shock transcription factor in Saccharomyces cerevisiae. J Biol Chem 2005; 280:11911-9. [PMID: 15647283 DOI: 10.1074/jbc.m411256200] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In response to hyperthermia, heat shock transcription factor (HSF) activates transcription of a set of genes encoding heat shock proteins (HSPs). The promoter regions of HSP genes contain the HSF binding sequence called the heat shock element (HSE), which consists of contiguous inverted repeats of the sequence 5'-nGAAn-3' (where n is any nucleotide). We have constructed an hsf1 mutant of Saccharomyces cerevisiae and analyzed genome-wide changes in heat shock response in the mutant cells. The results have revealed that Hsf1 is necessary for heat-induced transcription of not only HSP but also genes encoding proteins involved in diverse cellular processes such as protein degradation, detoxification, energy generation, carbohydrate metabolism, and maintenance of cell wall integrity. Approximately half of the Hsf1-regulated genes lacked the typical HSE in their promoter regions. Instead, several of these genes have a novel Hsf1 binding sequence that contains three direct repeats of nTTCn (or nGAAn) interrupted by 5 bp. The number and spacing of the repeating units are critical determinants for heat-induced transcription as well as for recognition by Hsf1. In the yeast genome, the presence of the sequence is enriched in Hsf1-regulated genes, suggesting that it is generally used as an HSE in the Hsf1 regulon.
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Affiliation(s)
- Ayako Yamamoto
- School of Health Sciences, Faculty of Medicine, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan
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46
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Mattie MD, Freedman JH. Copper-inducible transcription: regulation by metal- and oxidative stress-responsive pathways. Am J Physiol Cell Physiol 2004; 286:C293-301. [PMID: 14576086 DOI: 10.1152/ajpcell.00293.2003] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although copper is an essential metal, it is capable of catalyzing the formation of reactive oxygen species that can cause intracellular oxidative damage. We investigated the hypothesis that metal- and oxidative stress-responsive signal transduction pathways mediate the cellular and molecular responses associated with copper exposure. Transient transfection assays using COS-7 cells and mouse metallothionein-I (MT-I) or rat NAD(P)H:oxidoreductase 1-based reporter genes demonstrate that copper activates transcription via metal and antioxidant response elements. Concomitant with copper exposures is a decrease in the level of total glutathione and an increase in oxidized glutathione. Depletion of glutathione, before copper exposure, increases metal- and oxidative stress-inducible transcription and cytotoxicity. Pretreatment with the reactive oxygen scavengers aspirin or vitamin E provides partial protection against copper toxicity and reduces inducible transcription. Experiments using signal transduction inhibitors and a metal transcription factor (MTF)-1 null cell line demonstrate that copper-inducible MT-I transcription is regulated by protein kinase C and mitogen-activated protein kinase signaling pathways and requires MTF-1. The results of these studies indicate that copper activates transcription through both metal- and oxidative stress-responsive signal transduction pathways.
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Affiliation(s)
- Michael D Mattie
- Nicholas School of Environement and Earth Sciences, Duke University, Durham, NC 27708-0328, USA
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47
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Hahn JS, Thiele DJ. Activation of the Saccharomyces cerevisiae heat shock transcription factor under glucose starvation conditions by Snf1 protein kinase. J Biol Chem 2003; 279:5169-76. [PMID: 14612437 DOI: 10.1074/jbc.m311005200] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heat shock transcription factor (HSF) is an evolutionarily conserved protein that mediates eukaryotic transcriptional responses to stress. Although the mammalian stress-responsive HSF1 isoform is activated in response to a wide array of seemingly unrelated stresses, including heat shock, pharmacological agents, infection and inflammation, little is known about the precise mechanisms or pathways by which this factor is activated by many stressors. The baker's yeast Saccharomyces cerevisiae encodes a single HSF protein that responds to heat stress and glucose starvation and provides a simple model system to investigate how a single HSF is activated by multiple stresses. Although induction of the HSF target gene CUP1 by glucose starvation is dependent on the Snf1 kinase, HSF-dependent heat shock induction of CUP1 is Snf1-independent. Approximately 165 in vivo targets for HSF have been identified in S. cerevisiae using chromatin immunoprecipitation combined with DNA microarrays. Interestingly, approximately 30% of the HSF direct target genes are also induced by the diauxic shift, in which glucose levels begin to be depleted. We demonstrate that HSF and Snf1 kinase interact in vivo and that HSF is a direct substrate for phosphorylation by Snf1 kinase in vitro. Furthermore, glucose starvation-dependent, but not heat shock-dependent HSF phosphorylation, and enhanced chromosomal HSF DNA binding to low affinity target promoters such as SSA3 and HSP30, occurred in a Snf1-dependent manner. Consistent with a more global role for HSF and Snf1 in activating gene expression in response to changes in glucose availability, expression of a subset of HSF targets by glucose starvation was dependent on Snf1 and the HSF carboxyl-terminal activation domain.
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Affiliation(s)
- Ji-Sook Hahn
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0606, USA
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48
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Cooper B, Schneider S, Bohl J, Jiang YH, Beaudet A, Vande Pol S. Requirement of E6AP and the features of human papillomavirus E6 necessary to support degradation of p53. Virology 2003; 306:87-99. [PMID: 12620801 DOI: 10.1016/s0042-6822(02)00012-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
E6 oncoproteins from human papillomavirus type 16 (16E6) and Bovine Papillomavirus type 1 (BE6) bind to leucine rich peptides (called charged leucine, LXXLL, or signature peptides) found on target cellular proteins. BE6 and 16E6 both bind the product of the UBE3A gene called E6AP on a charged leucine peptide, LQELL. E6AP is an E3 ubiquitin ligase that together with 16E6 interacts with p53 to target p53 degradation. Although both BE6 and 16E6 bind the LQELL peptide of E6AP, only 16E6 acts as an adapter to then bring p53 to E6AP. In order to determine how E6 proteins function as adapters, 16E6, p53, and E6AP were expressed in yeast, and were shown to form a tri-molecular complex. 16E6 mutants were selected that retained interactions with E6AP yet were defective for interaction with p53. Such 16E6 mutations were typically within the amino-terminus of 16E6. Through the use of E6AP null cells, transfected E6AP was shown to be necessary and sufficient for the degradation of p53 in the presence of 16E6. However, the interaction of 16E6 with E6AP was complex. While BE6 interacts only with the LQELL motif of E6AP, an intact LQELL motif is not necessary either for interaction of 16E6 with E6AP or for p53 degradation. In addition, 16E6 mutants that fail to bind the LQELL motif of E6AP can support p53 degradation. These results indicate that 16E6 may have multiple modes of interaction with E6AP and that assembly of p53 containing complexes for targeted degradation by E6AP may occur in more than one way. These results have implications for potential targeting of the interaction of 16E6 and E6AP in the therapy of HPV-induced cancer.
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Affiliation(s)
- Brooke Cooper
- Institute of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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49
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50
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Adams TK, Saydam N, Steiner F, Schaffner W, Freedman JH. Activation of gene expression by metal-responsive signal transduction pathways. ENVIRONMENTAL HEALTH PERSPECTIVES 2002; 110 Suppl 5:813-7. [PMID: 12426137 PMCID: PMC1241251 DOI: 10.1289/ehp.02110s5813] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Metallothioneins are small, cysteine-rich, metal-binding proteins that play important roles in maintaining intracellular metal homeostasis and in transition metal detoxification. MTF-1 (metal transcription factor-1) plays a central role in regulating the metal-inducible, transcriptional activation of metallothionein. Here we report that the phosphorylation of MTF-1 plays a critical role in the activation of MTF-1/metal-responsive element-mediated transcription. Inhibitor studies indicate that signal transduction cascades, including those mediated by protein kinase C, tyrosine kinase, and casein kinase II, are essential for zinc- and cadmium-inducible transcription. In addition, calcium signaling is also involved in regulating transcription. In contrast, cAMP-dependent protein kinase may not be directly involved in the metal response. Contrary to what has been reported for other transcription factors, the inhibition of transcriptional activation does not impair the binding of MTF-1 to DNA, suggesting that phosphorylation is not regulating DNA binding. Elevated phosphorylation of MTF-1 is observed under conditions of protein kinase C inhibition, suggesting that dephosphorylation of this transcription factor mediates its activation.
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Affiliation(s)
- Timothy K Adams
- Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC 27708-0328, USA
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