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Condic N, Amiji H, Patel D, Shropshire WC, Lermi NO, Sabha Y, John B, Hanson B, Karras GI. Selection for robust metabolism in domesticated yeasts is driven by adaptation to Hsp90 stress. Science 2024; 385:eadi3048. [PMID: 39052788 DOI: 10.1126/science.adi3048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 12/31/2023] [Accepted: 05/24/2024] [Indexed: 07/27/2024]
Abstract
Protein folding both promotes and constrains adaptive evolution. We uncover this surprising duality in the role of the protein-folding chaperone heat shock protein 90 (Hsp90) in maintaining the integrity of yeast metabolism amid proteotoxic stressors within industrial domestication niches. Ethanol disrupts critical Hsp90-dependent metabolic pathways and exerts strong selective pressure for redundant duplications of key genes within these pathways, yielding the classical genomic signatures of beer and bread domestication. This work demonstrates a mechanism of adaptive canalization in an ecology of major economic importance and highlights Hsp90-dependent variation as an important source of phantom heritability in complex traits.
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Affiliation(s)
- Natalia Condic
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Hatim Amiji
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Dipak Patel
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - William Charles Shropshire
- Center for Infectious Diseases, Department of Epidemiology, Human Genetics and Environmental Sciences, UTHealth Houston School of Public Health, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center McGovern Medical School, Houston, TX, USA
| | - Nejla Ozirmak Lermi
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Youssef Sabha
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Beryl John
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Blake Hanson
- Center for Infectious Diseases, Department of Epidemiology, Human Genetics and Environmental Sciences, UTHealth Houston School of Public Health, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center McGovern Medical School, Houston, TX, USA
| | - Georgios Ioannis Karras
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Genetics and Epigenetics Graduate Program, The University of Texas MD Anderson Cancer Center, UTHealth Houston Graduate School of Biomedical Sciences, Houston, TX, USA
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Crandall JG, Fisher KJ, Sato TK, Hittinger CT. Ploidy evolution in a wild yeast is linked to an interaction between cell type and metabolism. PLoS Biol 2023; 21:e3001909. [PMID: 37943740 PMCID: PMC10635434 DOI: 10.1371/journal.pbio.3001909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 10/06/2023] [Indexed: 11/12/2023] Open
Abstract
Ploidy is an evolutionarily labile trait, and its variation across the tree of life has profound impacts on evolutionary trajectories and life histories. The immediate consequences and molecular causes of ploidy variation on organismal fitness are frequently less clear, although extreme mating type skews in some fungi hint at links between cell type and adaptive traits. Here, we report an unusual recurrent ploidy reduction in replicate populations of the budding yeast Saccharomyces eubayanus experimentally evolved for improvement of a key metabolic trait, the ability to use maltose as a carbon source. We find that haploids have a substantial, but conditional, fitness advantage in the absence of other genetic variation. Using engineered genotypes that decouple the effects of ploidy and cell type, we show that increased fitness is primarily due to the distinct transcriptional program deployed by haploid-like cell types, with a significant but smaller contribution from absolute ploidy. The link between cell-type specification and the carbon metabolism adaptation can be traced to the noncanonical regulation of a maltose transporter by a haploid-specific gene. This study provides novel mechanistic insight into the molecular basis of an environment-cell type fitness interaction and illustrates how selection on traits unexpectedly linked to ploidy states or cell types can drive karyotypic evolution in fungi.
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Affiliation(s)
- Johnathan G. Crandall
- Laboratory of Genetics, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kaitlin J. Fisher
- Laboratory of Genetics, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Trey K. Sato
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Chris Todd Hittinger
- Laboratory of Genetics, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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3
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Brouwers N, Brickwedde A, Gorter de Vries AR, van den Broek M, Weening SM, van den Eijnden L, Diderich JA, Bai FY, Pronk JT, Daran JMG. Himalayan Saccharomyces eubayanus Genome Sequences Reveal Genetic Markers Explaining Heterotic Maltotriose Consumption by Saccharomyces pastorianus Hybrids. Appl Environ Microbiol 2019; 85:e01516-19. [PMID: 31519660 PMCID: PMC6821976 DOI: 10.1128/aem.01516-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/04/2019] [Indexed: 12/27/2022] Open
Abstract
Saccharomyces pastorianus strains are hybrids of Saccharomyces cerevisiae and Saccharomyces eubayanus that have been domesticated for centuries in lager beer brewing environments. As sequences and structures of S. pastorianus genomes are being resolved, molecular mechanisms and evolutionary origins of several industrially relevant phenotypes remain unknown. This study investigates how maltotriose metabolism, a key feature in brewing, may have arisen in early S. eubayanus × S. cerevisiae hybrids. To address this question, we generated a nearly complete genome assembly of Himalayan S. eubayanus strains of the Holarctic subclade. This group of strains has been proposed to be the S. eubayanus subgenome origin of current S. pastorianus strains. The Himalayan S. eubayanus genomes harbored several copies of an S. eubayanusAGT1 (SeAGT1) α-oligoglucoside transporter gene with high sequence identity to genes encountered in S. pastorianus Although Himalayan S. eubayanus strains cannot grow on maltose and maltotriose, their maltose-hydrolase and SeMALT1 and SeAGT1 maltose transporter genes complemented the corresponding null mutants of S. cerevisiae Expression, in Himalayan S. eubayanus of a functional S. cerevisiae maltose metabolism regulator gene (MALx3) enabled growth on oligoglucosides. The hypothesis that the maltotriose-positive phenotype in S. pastorianus is a result of heterosis was experimentally tested by constructing an S. cerevisiae × S. eubayanus laboratory hybrid with a complement of maltose metabolism genes that resembles that of current S. pastorianus strains. The ability of this hybrid to consume maltotriose in brewer's wort demonstrated regulatory cross talk between subgenomes and thereby validated this hypothesis. These results support experimentally the new postulated hypothesis on the evolutionary origin of an essential phenotype of lager brewing strains and valuable knowledge for industrial exploitation of laboratory-made S. pastorianus-like hybrids.IMPORTANCES. pastorianus, an S. cerevisiae × S. eubayanus hybrid, is used for production of lager beer, the most produced alcoholic beverage worldwide. It emerged by spontaneous hybridization and colonized early lager brewing processes. Despite accumulation and analysis of genome sequencing data of S. pastorianus parental genomes, the genetic blueprint of industrially relevant phenotypes remains unresolved. Assimilation of maltotriose, an abundant sugar in wort, has been postulated to be inherited from the S. cerevisiae parent. Here, we demonstrate that although Asian S. eubayanus isolates harbor a functional maltotriose transporter SeAGT1 gene, they are unable to grow on α-oligoglucosides, but expression of S. cerevisiae regulator MAL13 (ScMAL13) was sufficient to restore growth on trisaccharides. We hypothesized that the S. pastorianus maltotriose phenotype results from regulatory interaction between S. cerevisiae maltose transcription activator and the promoter of SeAGT1 We experimentally confirmed the heterotic nature of the phenotype, and thus these results provide experimental evidence of the evolutionary origin of an essential phenotype of lager brewing strains.
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Affiliation(s)
- Nick Brouwers
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Anja Brickwedde
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Marcel van den Broek
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Susan M Weening
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Jasper A Diderich
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Feng-Yan Bai
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Jean-Marc G Daran
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
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4
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Brickwedde A, Brouwers N, van den Broek M, Gallego Murillo JS, Fraiture JL, Pronk JT, Daran JMG. Structural, Physiological and Regulatory Analysis of Maltose Transporter Genes in Saccharomyces eubayanus CBS 12357 T. Front Microbiol 2018; 9:1786. [PMID: 30147677 PMCID: PMC6097016 DOI: 10.3389/fmicb.2018.01786] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 07/17/2018] [Indexed: 11/13/2022] Open
Abstract
Saccharomyces pastorianus lager brewing yeasts are domesticated hybrids of Saccharomyces cerevisiae and cold-tolerant Saccharomyces eubayanus. To understand the contribution of both parental genomes to maltose metabolism in brewing wort, this study focuses on maltose transport in the S. eubayanus type strain CBS 12357T/FM1318. To obtain complete sequences of the MAL loci of this strain, a near-complete genome assembly was generated using the Oxford Nanopore Technology MinION sequencing platform. Except for CHRXII, all sixteen chromosomes were assembled as single contigs. Four loci harboring putative maltose transporter genes (SeMALT1-4), located in subtelomeric regions of CHRII, CHRV, CHRXIII, and CHRXVI, were completely resolved. The near-identical loci on CHRV and CHRXVI strongly resembled canonical S. cerevisiae MAL loci, while those on CHRII and CHRXIII showed different structures suggestive of gene loss. Overexpression of SeMALT1-4 in a maltose-transport-deficient S. cerevisiae strain restored growth on maltose, but not on maltotriose, indicating maltose-specific transport functionality of all four transporters. Simultaneous CRISPR-Cas9-assisted deletion of only SeMALT2 and SeMALT4, which shared 99.7% sequence identity, eliminated growth of S. eubayanus CBS 12357T on maltose. Transcriptome analysis of S. eubayanus CBS 12357T established that SeMALT1 and SeMALT3, are poorly expressed in maltose-grown cultures, while SeMALT2 and SeMALT4 were expressed at much higher levels than SeMALT1 and SeMALT3, indicating that only SeMALT2/4 are responsible for maltose consumption in CBS 12357T. These results represent a first genomic and physiological characterization of maltose transport in S. eubayanus CBS 12357T and provides a valuable resource for further industrial exploitation of this yeast.
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Affiliation(s)
- Anja Brickwedde
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Nick Brouwers
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | | | | | - Julie L Fraiture
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Jean-Marc G Daran
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
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5
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Viigand K, Põšnograjeva K, Visnapuu T, Alamäe T. Genome Mining of Non-Conventional Yeasts: Search and Analysis of MAL Clusters and Proteins. Genes (Basel) 2018; 9:E354. [PMID: 30013016 PMCID: PMC6070925 DOI: 10.3390/genes9070354] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/09/2018] [Accepted: 07/12/2018] [Indexed: 12/13/2022] Open
Abstract
Genomic clustering of functionally related genes is rare in yeasts and other eukaryotes with only few examples available. Here, we summarize our data on a nontelomeric MAL cluster of a non-conventional methylotrophic yeast Ogataea (Hansenula) polymorpha containing genes for α-glucosidase MAL1, α-glucoside permease MAL2 and two hypothetical transcriptional activators. Using genome mining, we detected MAL clusters of varied number, position and composition in many other maltose-assimilating non-conventional yeasts from different phylogenetic groups. The highest number of MAL clusters was detected in Lipomyces starkeyi while no MAL clusters were found in Schizosaccharomyces pombe and Blastobotrys adeninivorans. Phylograms of α-glucosidases and α-glucoside transporters of yeasts agreed with phylogenesis of the respective yeast species. Substrate specificity of unstudied α-glucosidases was predicted from protein sequence analysis. Specific activities of Scheffersomycesstipitis α-glucosidases MAL7, MAL8, and MAL9 heterologously expressed in Escherichia coli confirmed the correctness of the prediction-these proteins were verified promiscuous maltase-isomaltases. α-Glucosidases of earlier diverged yeasts L. starkeyi, B. adeninivorans and S. pombe showed sequence relatedness with α-glucosidases of filamentous fungi and bacilli.
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Affiliation(s)
- Katrin Viigand
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia.
| | - Kristina Põšnograjeva
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia.
| | - Triinu Visnapuu
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia.
| | - Tiina Alamäe
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia.
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Vidgren V, Gibson B. Trans-regulation and localization of orthologous maltose transporters in the interspecies lager yeast hybrid. FEMS Yeast Res 2018; 18:5040228. [PMID: 29931058 PMCID: PMC6142294 DOI: 10.1093/femsyr/foy065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/15/2018] [Indexed: 11/12/2022] Open
Abstract
In the interspecies lager yeast hybrid there are MAL loci involved in maltose and maltotriose utilization derived from each parent (Saccharomyces cerevisiae and Saccharomyces eubayanus). We show that trans-regulation across hybrid subgenomes occurs for MAL genes. However, gene expression is less efficient with non-native activators (trans-activation) compared to native activators (cis-activation). MAL genes were induced by maltose and repressed by glucose irrespective of host. Despite the strong expression of S. cerevisiae-type genes in the S. eubayanus host, a very low amount of transporter protein was actually observed in cells. This suggests that proper formation and configuration of the S. cerevisiae transporters is not efficient in S. eubayanus. The S. eubayanus-type Malx1 transporter was present in the plasma membrane in high amounts in all hosts (S. cerevisiae, S. eubayanus and Saccharomyces pastorianus) at all times. However, the S. cerevisiae-type transporters appeared sequentially in the plasma membrane; scMalx1 was localized in the plasma membrane during early to late linear growth and subsequently withdrawn to intracellular compartments. In contrast, the scAgt1 transporter was found in the plasma membrane mainly in the stationary phase of growth. Different localization patterns may explain why certain transporter orthologues in natural S. pastorianus strains were lost to mutation.
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Affiliation(s)
- Virve Vidgren
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT, Finland
| | - Brian Gibson
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT, Finland
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7
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Meurer M, Chevyreva V, Cerulus B, Knop M. The regulatableMAL32promoter inSaccharomyces cerevisiae: characteristics and tools to facilitate its use. Yeast 2016; 34:39-49. [DOI: 10.1002/yea.3214] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/01/2016] [Accepted: 09/23/2016] [Indexed: 11/09/2022] Open
Affiliation(s)
- Matthias Meurer
- Zentrum für Molekulare Biologie der Universität Heidelberg; University of Heidelberg; Im Neuenheimer Feld 282 69120 Heidelberg Germany
| | - Veronika Chevyreva
- Zentrum für Molekulare Biologie der Universität Heidelberg; University of Heidelberg; Im Neuenheimer Feld 282 69120 Heidelberg Germany
| | - Bram Cerulus
- KU Leuven Department Microbiële en Moleculaire Systemen; CMPG Laboratory of Genetics and Genomics; Gaston Geenslaan 1 3001 Leuven Belgium
- VIB Laboratory of Systems Biology; Gaston Geenslaan 1 3001 Leuven Belgium
| | - Michael Knop
- Zentrum für Molekulare Biologie der Universität Heidelberg; University of Heidelberg; Im Neuenheimer Feld 282 69120 Heidelberg Germany
- Deutsches Krebsforschungszentrum (DKFZ); Im Neuenheimer Feld 280 69120 Heidelberg Germany
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Gibson BR, Londesborough J, Rautio J, Mattinen L, Vidgren V. Transcription ofα-glucoside transport and metabolism genes in the hybrid brewing yeastSaccharomyces pastorianuswith respect to gene provenance and fermentation temperature. JOURNAL OF THE INSTITUTE OF BREWING 2013. [DOI: 10.1002/jib.66] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- B. R. Gibson
- VTT, Technical Research Centre of Finland; Tietotie 2, PO Box 1000; FI-02044 VTT; Espoo; Finland
| | - J. Londesborough
- VTT, Technical Research Centre of Finland; Tietotie 2, PO Box 1000; FI-02044 VTT; Espoo; Finland
| | - J. Rautio
- Plexpress Oy; Viikinkaari 6; 00790; Helsinki; Finland
| | - L. Mattinen
- Plexpress Oy; Viikinkaari 6; 00790; Helsinki; Finland
| | - V. Vidgren
- VTT, Technical Research Centre of Finland; Tietotie 2, PO Box 1000; FI-02044 VTT; Espoo; Finland
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9
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Regulations of sugar transporters: insights from yeast. Curr Genet 2013; 59:1-31. [PMID: 23455612 DOI: 10.1007/s00294-013-0388-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/28/2013] [Accepted: 02/02/2013] [Indexed: 12/24/2022]
Abstract
Transport across the plasma membrane is the first step at which nutrient supply is tightly regulated in response to intracellular needs and often also rapidly changing external environment. In this review, I describe primarily our current understanding of multiple interconnected glucose-sensing systems and signal-transduction pathways that ensure fast and optimum expression of genes encoding hexose transporters in three yeast species, Saccharomyces cerevisiae, Kluyveromyces lactis and Candida albicans. In addition, an overview of GAL- and MAL-specific regulatory networks, controlling galactose and maltose utilization, is provided. Finally, pathways generating signals inducing posttranslational degradation of sugar transporters will be highlighted.
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Meneses FJ, Jiranek V. Expression Patterns of Genes and Enzymes Involved in Sugar Catabolism in IndustrialSaccharomyces cerevisiaeStrains Displaying Novel Fermentation Characteristics. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2002.tb00557.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Vidgren V, Kankainen M, Londesborough J, Ruohonen L. Identification of regulatory elements in the AGT1 promoter of ale and lager strains of brewer's yeast. Yeast 2011; 28:579-94. [DOI: 10.1002/yea.1888] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 05/17/2011] [Indexed: 11/09/2022] Open
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Dietvorst J, Walsh MC, van Heusden GPH, Steensma HY. Comparison of the MTT1- and MAL31-like maltose transporter genes in lager yeast strains. FEMS Microbiol Lett 2010; 310:152-7. [PMID: 20698888 DOI: 10.1111/j.1574-6968.2010.02056.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Maltose transporter genes were isolated from four lager yeast strains and sequenced. All four strains contain at least two different types of maltose transporter genes, MTT1 and MAL31. In addition, 'long' 2.7 kb, and 'short' 2.4 kb, versions of each type exist. The size difference is caused by the insertion of two repeats of 147 bp into the promoter regions of the long versions of the genes. As a consequence of the insertion, two Mal63-binding sites move 294 bp away from the transcription initiation site. The 2.4- and 2.7-kb versions are further highly similar. Only the 2.4-kb versions and not the 2.7-kb versions of MTT1 could restore the rapid growth of lager yeast strain A15 on maltotriose in the presence of antimycin A. These results suggest that insertion of the two repeats into the promoter region of the 'long versions' of MTT1 genes led to a diminished expression of these genes. None of the tested long and short versions of the MAL31 genes were able to restore this growth. As the promoter regions of the MTT1 and MAL31 genes are identical, small differences in the protein sequence may be responsible for the different properties of these genes.
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Affiliation(s)
- Judith Dietvorst
- Section Molecular and Developmental Genetics, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
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Characterization and expression analysis of a maltose-utilizing (MAL) cluster in Aspergillus oryzae. Fungal Genet Biol 2010; 47:1-9. [PMID: 19850146 DOI: 10.1016/j.fgb.2009.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Revised: 10/08/2009] [Accepted: 10/13/2009] [Indexed: 11/22/2022]
Abstract
Starch and maltooligosaccharides such as maltose and maltotriose induce the production of amylolytic enzymes including alpha-amylase in Aspergillus oryzae. A transcriptional activator gene amyR, required for maltose induction of amylolytic enzymes, has been cloned and characterized. The amyR gene deletion mutant showed significantly poor growth on starch medium but normal growth on maltose medium. This indicated the existence of another maltose-utilizing system, whose expression might not be controlled by amyR. We have identified a gene cluster homologous to the MAL cluster of Saccharomyces cerevisiae in the A. oryzae genome. The cluster consists of a MAL61 homolog (designated malP), a MAL62 homolog (designated malT), and a MAL63 homolog (designated malR). Overexpression of malT in A. oryzae resulted in a significant increase in intracellular alpha-glucosidase activity, and that of malP allowed S. cerevisiaemal61Delta to grow on maltose. The expression of both malP and malT genes was highly up-regulated in the presence of maltose, but malR expressed constitutively irrespective of carbon sources. Disruption of malR resulted in the loss of malP and malT expression and thus in restricted growth on maltose medium. In addition, a malP disruptant showed a significantly reduced expression of malT and malR and exhibited a growth defect on maltose similar to the malR disruptant. These results suggest that the MAL cluster of A. oryzae is responsible for the assimilation of maltose in A. oryzae.
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N-acetylglucosamine utilization by Saccharomyces cerevisiae based on expression of Candida albicans NAG genes. Appl Environ Microbiol 2009; 75:5840-5. [PMID: 19648376 DOI: 10.1128/aem.00053-09] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Synthesis of chitin de novo from glucose involves a linear pathway in Saccharomyces cerevisiae. Several of the pathway genes, including GNA1, are essential. Genes for chitin catabolism are absent in S. cerevisiae. Therefore, S. cerevisiae cannot use chitin as a carbon source. Chitin is the second most abundant polysaccharide after cellulose and consists of N-acetylglucosamine (GlcNAc) moieties. Here, we have generated S. cerevisiae strains that are able to use GlcNAc as a carbon source by expressing four Candida albicans genes (NAG3 or its NAG4 paralog, NAG5, NAG2, and NAG1) encoding a GlcNAc permease, a GlcNAc kinase, a GlcNAc-6-phosphate deacetylase, and a glucosamine-6-phosphate deaminase, respectively. Expression of NAG3 and NAG5 or NAG4 and NAG5 in S. cerevisiae resulted in strains in which the otherwise-essential ScGNA1 could be deleted. These strains required the presence of GlcNAc in the medium, indicating that uptake of GlcNAc and its phosphorylation were achieved. Expression of all four NAG genes produced strains that could use GlcNAc as the sole carbon source for growth. Utilization of a GlcNAc catabolic pathway for bioethanol production using these strains was tested. However, fermentation was slow and yielded only minor amounts of ethanol (approximately 3.0 g/liter), suggesting that fructose-6-phosphate produced from GlcNAc under these conditions is largely consumed to maintain cellular functions and promote growth. Our results present the first step toward tapping a novel, renewable carbon source for biofuel production.
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Hatanaka H, Omura F, Kodama Y, Ashikari T. Gly-46 and His-50 of yeast maltose transporter Mal21p are essential for its resistance against glucose-induced degradation. J Biol Chem 2009; 284:15448-57. [PMID: 19359240 DOI: 10.1074/jbc.m808151200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The maltose transporter gene is situated at the MAL locus, which consists of genes for a transporter, maltase, and transcriptional activator. Five unlinked MAL loci (MAL1, MAL2, MAL3, MAL4, and MAL6) constitute a gene family in Saccharomyces cerevisiae. The expression of the maltose transporter is induced by maltose and repressed by glucose. The activity of the maltose transporter is also regulated post-translationally; Mal61p is rapidly internalized from the plasma membrane and degraded by ubiquitin-mediated proteolysis in the presence of glucose. We found that S. cerevisiae strain ATCC20598 harboring MAL21 could grow in maltose supplemented with a non- assimilable glucose analogue, 2-deoxyglucose, whereas strain ATCC96955 harboring MAL61 and strain CB11 with MAL31 and AGT1 could not. These observations implied a Mal21p-specific resistance against glucose-induced degradation. Mal21p found in ATCC20598 has 10 amino acids, including Gly-46 and His-50, that are inconsistent with the corresponding residues in Mal61p. The half-life of Mal21p for glucose-induced degradation was 118 min when expressed using the constitutive TPI1 promoter, which was significantly longer than that of Mal61p (25 min). Studies with mutant cells that are defective in endocytosis or the ubiquitination process indicated that Mal21p was less ubiquitinated than Mal61p, suggesting that Mal21p remains on the plasma membrane because of poor susceptibility to ubiquitination. Mutational studies revealed that both residues Gly-46 and His-50 in Mal21p are essential for the full resistance of maltose transporters against glucose-induced degradation.
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16
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Improved fermentation performance of a lager yeast after repair of its AGT1 maltose and maltotriose transporter genes. Appl Environ Microbiol 2009; 75:2333-45. [PMID: 19181838 DOI: 10.1128/aem.01558-08] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The use of more concentrated, so-called high-gravity and very-high-gravity (VHG) brewer's worts for the manufacture of beer has economic and environmental advantages. However, many current strains of brewer's yeasts ferment VHG worts slowly and incompletely, leaving undesirably large amounts of maltose and especially maltotriose in the final beers. alpha-Glucosides are transported into Saccharomyces yeasts by several transporters, including Agt1, which is a good carrier of both maltose and maltotriose. The AGT1 genes of brewer's ale yeast strains encode functional transporters, but the AGT1 genes of the lager strains studied contain a premature stop codon and do not encode functional transporters. In the present work, one or more copies of the AGT1 gene of a lager strain were repaired with DNA sequence from an ale strain and put under the control of a constitutive promoter. Compared to the untransformed strain, the transformants with repaired AGT1 had higher maltose transport activity, especially after growth on glucose (which represses endogenous alpha-glucoside transporter genes) and higher ratios of maltotriose transport activity to maltose transport activity. They fermented VHG (24 degrees Plato) wort faster and more completely, producing beers containing more ethanol and less residual maltose and maltotriose. The growth and sedimentation behaviors of the transformants were similar to those of the untransformed strain, as were the profiles of yeast-derived volatile aroma compounds in the beers.
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17
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Gibson BR, Boulton CA, Box WG, Graham NS, Lawrence SJ, Linforth RST, Smart KA. Carbohydrate utilization and the lager yeast transcriptome during brewery fermentation. Yeast 2009; 25:549-62. [PMID: 18668645 DOI: 10.1002/yea.1609] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The fermentable carbohydrate composition of wort and the manner in which it is utilized by yeast during brewery fermentation have a direct influence on fermentation efficiency and quality of the final product. In this study the response of a brewing yeast strain to changes in wort fermentable carbohydrate concentration and composition during full-scale (3275 hl) brewery fermentation was investigated by measuring transcriptome changes with the aid of oligonucleotide-based DNA arrays. Up to 74% of the detectable genes showed a significant (p</=0.01) differential expression pattern during fermentation and the majority of these genes showed transient or prolonged peaks in expression following the exhaustion of the monosaccharides from the wort. Transcriptional activity of many genes was consistent with their known responses to glucose de/repression under laboratory conditions, despite the presence of di- and trisaccharide sugars in the wort. In a number of cases the transcriptional response of genes was not consistent with their known responses to glucose, suggesting a degree of complexity during brewery fermentation which cannot be replicated in small-scale wort fermentations or in laboratory experiments involving defined media.
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Affiliation(s)
- Brian R Gibson
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, UK
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18
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Viigand K, Tammus K, Alamäe T. Clustering of MAL genes in Hansenula polymorpha: cloning of the maltose permease gene and expression from the divergent intergenic region between the maltose permease and maltase genes. FEMS Yeast Res 2005; 5:1019-28. [PMID: 16103021 DOI: 10.1016/j.femsyr.2005.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2005] [Revised: 05/19/2005] [Accepted: 06/17/2005] [Indexed: 11/20/2022] Open
Abstract
Hansenula polymorpha uses maltase to grow on maltose and sucrose. Inspection of genomic clones of H. polymorpha showed that the maltase gene HPMAL1 is clustered with genes corresponding to Saccharomyces cerevisiae maltose permeases and MAL activator genes orthologues. We sequenced the H. polymorpha maltose permease gene HPMAL2 of the cluster. The protein (582 amino acids) deduced from the HPMAL2 gene is predicted to have eleven transmembrane domains and shows 39-57% identity with yeast maltose permeases. The identity of the protein is highest with maltose permeases of Debaryomyces hansenii and Candida albicans. Expression of the HPMAL2 in a S. cerevisiae maltose permease-negative mutant CMY1050 proved functionality of the permease protein encoded by the gene. HPMAL1 and HPMAL2 genes are divergently positioned similarly to maltase and maltose permease genes in many yeasts. A two-reporter assay of the expression from the HPMAL1-HPMAL2 intergenic region showed that expression of both genes is coordinately regulated, repressed by glucose, induced by maltose, and that basal expression is higher in the direction of the permease gene.
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Affiliation(s)
- Katrin Viigand
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
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19
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Wang X, Michels CA. Mutations in SIN4 and RGR1 cause constitutive expression of MAL structural genes in Saccharomyces cerevisiae. Genetics 2005; 168:747-57. [PMID: 15514050 PMCID: PMC1448850 DOI: 10.1534/genetics.104.029611] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Transcription of the Saccharomyces MAL structural genes is induced 40-fold by maltose and requires the MAL-activator and maltose permease. To identify additional players involved in regulating MAL gene expression, we carried out a genetic selection for MAL constitutive mutants. Strain CMY4000 containing MAL1 and integrated copies of MAL61promoter-HIS3 and MAL61promoter-lacZ reporter genes was used to select constitutive mutants. The 29 recessive mutants fall into at least three complementation groups. Group 1 and group 2 mutants exhibit pleiotropic phenotypes and represent alleles of Mediator component genes RGR1 and SIN4, respectively. The rgr1 and sin4 constitutive phenotype does not require either the MAL-activator or maltose permease, indicating that Mediator represses MAL basal expression. Further genetic analysis demonstrates that RGR1 and SIN4 work in a common pathway and each component of the Mediator Sin4 module plays a distinct role in regulating MAL gene expression. Additionally, the Swi/Snf chromatin-remodeling complex is required for full induction, suggesting a role for chromatin remodeling in the regulation of MAL gene expression. A sin4Delta mutation is unable to suppress the defects in MAL gene expression resulting from loss of the Swi/Snf complex component Snf2p. The role of the Mediator in MAL gene regulation is discussed.
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Affiliation(s)
- Xin Wang
- Department of Biology, Queens College and the Graduate School of City University of New York, Flushing, New York 11367, USA
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20
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Alves-Araújo C, Hernandez-Lopez MJ, Sousa MJ, Prieto JA, Randez-Gil F. Cloning and characterization of the MAL11 gene encoding a high-affinity maltose transporter from Torulaspora delbrueckii. FEMS Yeast Res 2004; 4:467-76. [PMID: 14734027 DOI: 10.1016/s1567-1356(03)00208-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The transport and regulation of maltose utilization by Torulaspora delbrueckii, one of the most abundant non-Saccharomyces species present in home-made corn and rye bread dough, has been investigated. A DNA fragment containing the MAL11 gene from T. delbrueckii (TdMAL11) was isolated by complementation cloning in Saccharomyces cerevisiae. DNA sequence analysis revealed the presence of an open reading frame (ORF) of 1884 bp, encoding a 627-amino acid membrane protein, which displays high homology to other yeast maltose transporters. Upstream of TdMAL11, the DNA insert contained a partial ORF (TdMAL12) on the opposite strand, which showed high similarity to the S. cerevisiae MAL12 gene. Sequence analysis, Northern blot and transport measurements indicated that TdMAL11 expression is regulated by the carbon source. Attempts to disrupt TdMAL11 revealed the presence of two functional MAL loci. Disruption of a single copy decreased the V(max) of maltose transport, but not the K(m), whereas the double disruption abolished the uptake of this sugar in T. delbrueckii.
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Affiliation(s)
- Cecília Alves-Araújo
- Department of Biology, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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21
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Daran-Lapujade P, Jansen MLA, Daran JM, van Gulik W, de Winde JH, Pronk JT. Role of transcriptional regulation in controlling fluxes in central carbon metabolism of Saccharomyces cerevisiae. A chemostat culture study. J Biol Chem 2003; 279:9125-38. [PMID: 14630934 DOI: 10.1074/jbc.m309578200] [Citation(s) in RCA: 210] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In contrast to batch cultivation, chemostat cultivation allows the identification of carbon source responses without interference by carbon-catabolite repression, accumulation of toxic products, and differences in specific growth rate. This study focuses on the yeast Saccharomyces cerevisiae, grown in aerobic, carbon-limited chemostat cultures. Genome-wide transcript levels and in vivo fluxes were compared for growth on two sugars, glucose and maltose, and for two C2-compounds, ethanol and acetate. In contrast to previous reports on batch cultures, few genes (180 genes) responded to changes of the carbon source by a changed transcript level. Very few transcript levels were changed when glucose as the growth-limiting nutrient was compared with maltose (33 transcripts), or when acetate was compared with ethanol (16 transcripts). Although metabolic flux analysis using a stoichiometric model revealed major changes in the central carbon metabolism, only 117 genes exhibited a significantly different transcript level when sugars and C2-compounds were provided as the growth-limiting nutrient. Despite the extensive knowledge on carbon source regulation in yeast, many of the carbon source-responsive genes encoded proteins with unknown or incompletely characterized biological functions. In silico promoter analysis of carbon source-responsive genes confirmed the involvement of several known transcriptional regulators and suggested the involvement of additional regulators. Transcripts involved in the glyoxylate cycle and gluconeogenesis showed a good correlation with in vivo fluxes. This correlation was, however, not observed for other important pathways, including the pentose-phosphate pathway, tricarboxylic acid cycle, and, in particular, glycolysis. These results indicate that in vivo fluxes in the central carbon metabolism of S. cerevisiae grown in steadystate, carbon-limited chemostat cultures are controlled to a large extent via post-transcriptional mechanisms.
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Affiliation(s)
- Pascale Daran-Lapujade
- Kluyver Laboratory of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
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22
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Bali M, Zhang B, Morano KA, Michels CA. The Hsp90 molecular chaperone complex regulates maltose induction and stability of the Saccharomyces MAL gene transcription activator Mal63p. J Biol Chem 2003; 278:47441-8. [PMID: 14500708 DOI: 10.1074/jbc.m309536200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Induction of the Saccharomyces MAL structural genes encoding maltose permease and maltase requires the MAL activator, a DNA-binding transcription activator. Genetic analysis of MAL activator mutations suggested that protein folding and stability play an important role in MAL activator regulation and led us to explore the role of the Hsp90 molecular chaperone complex in the regulation of the MAL activator. Strains carrying mutations in genes encoding components of the Hsp90 chaperone complex, hsc82 Delta hsp82-T101I and hsc82 Delta cpr7 Delta, are defective for maltase induction and exhibit significantly reduced growth rates on media containing a limiting concentration of maltose (0.05%). This growth defect is suppressed by providing maltose in excess. Using epitope-tagged alleles of the MAL63 MAL activator, we showed that Mal63p levels are drastically reduced following depletion of cellular Hsp90. Overexpression ( approximately 3-fold) of Mal63p in the hsc82 Delta hsp82-T101I and hsc82 Delta cpr7 Delta strains suppresses their Mal- growth phenotype, suggesting that Mal63p levels are limiting for maltose utilization in strains with abrogated Hsp90 activity. Consistent with this, the half-life of Mal63p is significantly shorter in the hsc82 Delta cpr7 Delta strain (reduced about 6-fold) and modestly affected in the Hsp90-ts strain (reduced about 2-fold). Most importantly, triple hemagglutinin-tagged Mal63p protein is found in association with Hsp90 as demonstrated by co-immunoprecipitation. Taken together, these results identify the inducible MAL activator as a client protein of the Hsp90 molecular chaperone complex and point to a critical role for chaperone function in alternate carbon source utilization in Saccharomyces cerevisiae.
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Affiliation(s)
- Mehtap Bali
- Biology Department, Queens College and the Graduate School of the City University of New York, Flushing, New York 11367, USA
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23
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Rolim MF, de Araujo PS, Panek AD, Paschoalin VMF, Silva JT. Shared control of maltose and trehalose utilization in Candida utilis. Braz J Med Biol Res 2003; 36:829-37. [PMID: 12845368 DOI: 10.1590/s0100-879x2003000700002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Trehalose biosynthesis and its hydrolysis have been extensively studied in yeast, but few reports have addressed the catabolism of exogenously supplied trehalose. Here we report the catabolism of exogenous trehalose by Candida utilis. In contrast to the biphasic growth in glucose, the growth of C. utilis in a mineral medium with trehalose as the sole carbon and energy source is aerobic and exhibits the Kluyver effect. Trehalose is transported into the cell by an inducible trehalose transporter (K M of 8 mM and V MAX of 1.8 mol trehalose min-1 mg cell (dry weight)-1. The activity of the trehalose transporter is high in cells growing in media containing trehalose or maltose and very low or absent during the growth in glucose or glycerol. Similarly, total trehalase activity was increased from about 1.0 mU/mg protein in cells growing in glucose to 39.0 and 56.2 mU/mg protein in cells growing in maltose and trehalose, respectively. Acidic and neutral trehalase activities increased during the growth in trehalose, with neutral trehalase contributing to about 70% of the total activity. In addition to the increased activities of the trehalose transporter and trehalases, growth in trehalose promoted the increase in the activity of alpha-glucosidase and the maltose transporter. These results clearly indicate that maltose and trehalose promote the increase of the enzymatic activities necessary to their catabolism but are also able to stimulate each other's catabolism, as reported to occur in Escherichia coli. We show here for the first time that trehalose induces the catabolism of maltose in yeast.
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Affiliation(s)
- M F Rolim
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
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24
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Day RE, Higgins VJ, Rogers PJ, Dawes IW. Characterization of the putative maltose transporters encoded by YDL247w and YJR160c. Yeast 2002; 19:1015-27. [PMID: 12210897 DOI: 10.1002/yea.894] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The maltose permease family of Saccharomyces cerevisiae comprises five proteins, three of which are characterized, MAL31, MAL61 and AGT1 and two putative permeases, YDL247w (MPH2) and YJR160c (MPH3). The two uncharacterized permeases share 100% identity and have 75% identity with MAL31 and MAL61 and 55% identity with AGT1. Characterization of the genes YDL247w and YJR160c confirmed that they encode alpha-glucoside permeases capable of transporting maltose, maltotriose, alpha-methylglucoside and turanose. Analysis of the promoter regions identified regulatory elements, binding sites for the transcriptional activator, Malx3p and the inhibitory protein, Mig1p. Further analysis of the flanking sequences located blocks of identity covering five open reading frames, indicating that this region was involved in chromosomal block duplication. The members of the maltose permease family are proteins that have strongly overlapping but nevertheless distinct functions, which is a selective advantage for yeast, as it reflects successful adaptation to the variety of environmental conditions to which the yeast cells are exposed; such adaptability is very important in an industrial context.
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Affiliation(s)
- Rachel E Day
- Clive and Vera Ramaciotti Centre for Gene Function Analysis, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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25
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Finley RL, Zhang H, Zhong J, Stanyon CA. Regulated expression of proteins in yeast using the MAL61-62 promoter and a mating scheme to increase dynamic range. Gene 2002; 285:49-57. [PMID: 12039031 DOI: 10.1016/s0378-1119(02)00420-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ability to express heterologous genes in yeast has become indispensable for many biological research techniques. Expression systems that can be regulated are particularly useful because they allow an experimenter to control the timing and levels of gene expression. Despite their many advantages, however, surprisingly few conditional expression systems are available for yeast. Moreover, of those that have been described, many are not ideal either because they have high background expression levels, low induced levels, or because they require restrictive growth conditions. Here we describe a conditional expression system that takes advantage of the yeast MAL62 promoter (MAL62p), which can be controlled by adding maltose or glucose to the growth medium to induce or repress transcription, respectively. In addition, we use a mating scheme to dramatically increase the dynamic range of expression levels possible. We show that MAL62p background activity can be effectively eliminated by maintaining expression constructs in a mal(-) yeast strain. High-level expression can be induced in diploids formed by mating the mal(-) strain with a MAL(+) strain. A similar mating scheme may be useful for other conditional expression systems as well. Among other uses, this approach should aid high throughput yeast two-hybrid assays, which rely on maintaining large libraries of expression strains, which are eventually mated to conduct assays for protein interactions. We demonstrate a two-hybrid system in which MAL62p is used in conjunction with the yeast GAL1 promoter to independently regulate expression of both hybrid proteins, and to allow detection of interactions involving toxic proteins.
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Affiliation(s)
- Russell L Finley
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, 540 East Canfield Avenue, Detroit, MI 48201, USA.
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26
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Bell PJ, Davies IW, Attfield PV. Facilitating functional analysis of the Saccharomyces cerevisiae genome using an EGFP-based promoter library and flow cytometry. Yeast 1999; 15:1747-59. [PMID: 10590463 DOI: 10.1002/(sici)1097-0061(199912)15:16<1747::aid-yea492>3.0.co;2-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
A promoter library was generated to facilitate identification of differentially regulated promoters in Saccharomyces cerevisiae. The library was constructed in a vector containing two reporter genes (EGFP and lacZ) divergently arranged about a unique cloning site. Approximately 2x10(5) clones were obtained and a flow cytometer was used to screen the library for copper-induced EGFP expression. A DNA fragment conferring copper-inducible expression of EGFP was rapidly identified. This DNA fragment, which contained several motifs associated with copper and oxidative stress homeostasis, lies upstream of two 'orphan' genes of unknown function. Further studies comparing expression from episomal vs. integrative vectors showed that construction of a similar library using an integrative vector would further enhance rapid identification of genes that are differentially regulated in S. cerevisiae. The ability to identify regulated promoters rapidly should facilitate the functional analysis of the yeast genome by identifying genes induced by specific physiological conditions.
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Affiliation(s)
- P J Bell
- Burns Philp Research and Development, 67 Epping Road, North Ryde, New South Wales 2113, Australia.
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27
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Hon T, Hach A, Tamalis D, Zhu Y, Zhang L. The yeast heme-responsive transcriptional activator Hap1 is a preexisting dimer in the absence of heme. J Biol Chem 1999; 274:22770-4. [PMID: 10428861 DOI: 10.1074/jbc.274.32.22770] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the absence of heme, Hap1 is associated with molecular chaperones such as Hsp90 and Ydj1 and forms a higher order complex termed HMC. Heme disrupts this complex and permits Hap1 to bind to DNA with high affinity, thereby activating transcription. Heme regulation of Hap1 activity is analogous to the regulation of steroid receptors by steroids, which involves molecular chaperones. Steroid receptors often exist as monomers when associated with molecular chaperones in the absence of ligand but as dimers when activated by steroids. Furthermore, previous studies indicate that dimerization might be important for heme activation of Hap1. We therefore determined whether Hap1 is a monomer or oligomer in the absence of heme. By coeluting two Hap1 size variants and by comparing DNA binding properties of the HMC and Hap1 dimer, we show that Hap1 is a preexisting dimer in the HMC. Further, increasing overexpression of Hap1 caused progressive increases in Hap1 DNA binding and transcriptional activities. Our data suggest that in the absence of heme, Hap1 exists as a dimer, and the two subunits act cooperatively in DNA binding. Hap1 repression is caused, at least in part, by inhibition of the DNA binding activity of the preexisting dimer.
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Affiliation(s)
- T Hon
- Department of Biochemistry, New York University Medical Center, New York, New York 10016, USA
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28
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Higgins VJ, Braidwood M, Bell P, Bissinger P, Dawes IW, Attfield PV. Genetic evidence that high noninduced maltase and maltose permease activities, governed by MALx3-encoded transcriptional regulators, determine efficiency of gas production by baker's yeast in unsugared dough. Appl Environ Microbiol 1999; 65:680-5. [PMID: 9925600 PMCID: PMC91079 DOI: 10.1128/aem.65.2.680-685.1999] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Strain selection and improvement in the baker's yeast industry have aimed to increase the speed of maltose fermentation in order to increase the leavening activity of industrial baking yeast. We identified two groups of baker's strains of Saccharomyces cerevisiae that can be distinguished by the mode of regulation of maltose utilization. One group (nonlagging strains), characterized by rapid maltose fermentation, had at least 12-fold more maltase and 130-fold-higher maltose permease activities than maltose-lagging strains in the absence of inducing sugar (maltose) and repressing sugar (glucose). Increasing the noninduced maltase activity of a lagging strain 13-fold led to an increase in CO2 production in unsugared dough. This increase in CO2 production also was seen when the maltose permease activity was increased 55-fold. Only when maltase and maltose permease activities were increased in concert was CO2 production by a lagging strain similar to that of a nonlagging strain. The noninduced activities of maltase and maltose permease constitute the largest determinant of whether a strain displays a nonlagging or a lagging phenotype and are dependent upon the MALx3 allele. Previous strategies for strain improvement have targeted glucose derepression of maltase and maltose permease expression. Our results suggest that increasing noninduced maltase and maltose permease levels is an important target for improved maltose metabolism in unsugared dough.
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Affiliation(s)
- V J Higgins
- School of Biochemistry and Molecular Genetics, University of New South Wales, Sydney, New South Wales 2052, Australia
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29
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Abstract
Glucose and related sugars repress the transcription of genes encoding enzymes required for the utilization of alternative carbon sources; some of these genes are also repressed by other sugars such as galactose, and the process is known as catabolite repression. The different sugars produce signals which modify the conformation of certain proteins that, in turn, directly or through a regulatory cascade affect the expression of the genes subject to catabolite repression. These genes are not all controlled by a single set of regulatory proteins, but there are different circuits of repression for different groups of genes. However, the protein kinase Snf1/Cat1 is shared by the various circuits and is therefore a central element in the regulatory process. Snf1 is not operative in the presence of glucose, and preliminary evidence suggests that Snf1 is in a dephosphorylated state under these conditions. However, the enzymes that phosphorylate and dephosphorylate Snf1 have not been identified, and it is not known how the presence of glucose may affect their activity. What has been established is that Snf1 remains active in mutants lacking either the proteins Grr1/Cat80 or Hxk2 or the Glc7 complex, which functions as a protein phosphatase. One of the main roles of Snf1 is to relieve repression by the Mig1 complex, but it is also required for the operation of transcription factors such as Adr1 and possibly other factors that are still unidentified. Although our knowledge of catabolite repression is still very incomplete, it is possible in certain cases to propose a partial model of the way in which the different elements involved in catabolite repression may be integrated.
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Affiliation(s)
- J M Gancedo
- Instituto de Investigaciones Biomédicas, Unidad de Bioquímica y Genética de Levaduras, CSIC, 28029 Madrid, Spain.
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30
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Bell PJ, Higgins VJ, Dawes IW, Bissinger PH. Tandemly repeated 147 bp elements cause structural and functional variation in divergent MAL promoters of Saccharomyces cerevisiae. Yeast 1997; 13:1135-44. [PMID: 9301020 DOI: 10.1002/(sici)1097-0061(19970930)13:12<1135::aid-yea162>3.0.co;2-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have studied four novel MAL promoters isolated from a single strain of bakers' yeast. Within these promoters we have identified up to five tandem 147 bp repeats located between the MAL UAS region and the MALT TATA box. These repeats strongly reduce MALT (maltose permease) gene expression but only weakly reduce MALS (maltase) gene expression. Insertion of the 147 bp elements into the heterologous CYC1 promoter reduced expression when located between the CYC1 UAS and the TATA box, but not when located upstream of the UAS. We propose that these naturally occurring repeats have evolved as a mechanism to lower the level of MALT expression relative of MALS expression, thus avoiding possible toxic effects associated with over-expression from multiple copies of the permease gene.
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Affiliation(s)
- P J Bell
- Burns Philp Research and Development, New South Wales, Australia
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31
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Todd RB, Andrianopoulos A. Evolution of a fungal regulatory gene family: the Zn(II)2Cys6 binuclear cluster DNA binding motif. Fungal Genet Biol 1997; 21:388-405. [PMID: 9290251 DOI: 10.1006/fgbi.1997.0993] [Citation(s) in RCA: 206] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The coevolution of DNA binding proteins and their cognate binding sites is essential for the maintenance of function. As a result, comparison of DNA binding proteins of unknown function in one species with characterized DNA binding proteins in another can identify potential targets and functions. The Zn(II)2Cys6 (or C6 zinc) binuclear cluster DNA binding domain has thus far been identified exclusively in fungal proteins, generally transcriptional regulators, and there are more than 80 known or predicted proteins which contain this motif, the best characterized of which are GAL4, PPR1, LEU3, HAP1, LAC9, and PUT3. Here we review all known proteins containing the Zn(II)2Cys6 motif, along with their function, DNA binding, dimerization, and zinc(II) coordination properties and DNA binding sites. In addition, we have identified all of the Zn(II)2Cys6 motif-containing proteins in the sequence databases, including a large number with unknown function from the completed Saccharomyces cerevisiae and ongoing Schizosaccharomyces pombe genome projects, and examined the phylogenetic relationships of all the Zn(II)2Cys6 motifs from these proteins. Based on these relationships, we have assigned potential functions to a number of these unknown proteins.
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Affiliation(s)
- R B Todd
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
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32
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Wang J, Sirenko O, Needleman R. Genomic footprinting of Mig1p in the MAL62 promoter. Binding is dependent upon carbon source and competitive with the Mal63p activator. J Biol Chem 1997; 272:4613-22. [PMID: 9020190 DOI: 10.1074/jbc.272.7.4613] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Mig1p inhibits gene expression in glucose by binding the Cyc8p (Ssn6p)-Tup1p repressor to the promoter of glucose-repressible genes. While the binding properties of Mig1p have been studied in vitro and the ability of Mig1p-Cyc8p (Ssn6p)-Tup1p to repress has been studied in vivo, no experiments have measured the effect of a carbon source on the in vivo binding of Mig1p or the effect of bound MIg1p on activator occupancy of the upstream activation sequence (UAS). To obtain this information, we used genomic footprinting to investigate glucose repression of MAL62, a gene that is also regulated by the Mal63p activator. These experiments show that two interrelated mechanisms are involved in the glucose repression of MAL62: 1) competition between the Mal63p activator and Mig1p for DNA binding and 2) modulation of Mig1p binding by the carbon source. Mig1p affects basal MAL62 expression in the absence of Mal63p by binding to a site in the MAL62 promoter and affects Mal63p-dependent synthesis by also inhibiting the access of Mal63p to site 1 in the UASMAL. The binding of Mig1p is increased in glucose and decreased in nonrepressing sugars, but the increased binding in glucose is not due to an increase in the levels of Mig1p.
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Affiliation(s)
- J Wang
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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Svetlov VV, Cooper TG. Review: compilation and characteristics of dedicated transcription factors in Saccharomyces cerevisiae. Yeast 1995; 11:1439-84. [PMID: 8750235 DOI: 10.1002/yea.320111502] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- V V Svetlov
- Department of Microbiology and Immunology, University of Tennessee, Memphis 36163, USA
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Bell PJ, Bissinger PH, Evans RJ, Dawes IW. A two-reporter gene system for the analysis of bi-directional transcription from the divergent MAL6T-MAL6S promoter in Saccharomyces cerevisiae. Curr Genet 1995; 28:441-6. [PMID: 8575017 DOI: 10.1007/bf00310813] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Many sets of genes in Saccharomyces cerevisiae are divergently transcribed, but at present there are no vectors generally available for the simultaneous analysis of divergent transcription from these promoters. In the present study MEL1 and lacZ were used to construct a vector capable of measuring the divergent expression initiated by the MAL6T-MAL6S bi-directional promoter. Our observations demonstrate that the expression of both reporter genes was regulated in a similar fashion to the native MAL6T and MAL6S genes, and that induction was dependent upon the presence of a functional MALR activator gene. The results confirmed that the MAL6T-MAL6S promoter was co-ordinately regulated, repressed by glucose, induced by maltose, and that basal expression was more active in the MAL6S direction than in the MAL6T direction.
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Affiliation(s)
- P J Bell
- C.R.C. for Food Industry Innovation, Sydney, New South Wales, Australia
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Hu Z, Nehlin JO, Ronne H, Michels CA. MIG1-dependent and MIG1-independent glucose regulation of MAL gene expression in Saccharomyces cerevisiae. Curr Genet 1995; 28:258-66. [PMID: 8529272 DOI: 10.1007/bf00309785] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucose repression is a global regulatory system in Saccharomyces cerevisiae controlling carbon-source utilization, mitochondrial biogenesis, gluconeogenesis and other metabolic pathways. Mig1p, a zinc-finger class of DNA-binding protein, is a transcriptional repressor regulating GAL and SUC gene expression in response to glucose. This report demonstrates that Mig1 protein represses transcription of the MAL61 and MAL62 structural genes and also the MAL63 gene, which encodes the Mal-activator. Mig1p DNA-binding sites were identified upstream of all three MAL genes. Both of the Mig1p-binding sites found in the bidirectional MAL61-MAL62 promoter were shown to function in the Mig1p-dependent glucose repression. Studies using constitutive Mal-activator alleles suggest that glucose regulation of inducer availability is a second major contributing factor in glucose repression of MAL gene expression and is even stronger than the Mig1p-dependent component of repression. Moreover, our results also suggest the contribution of other minor mechanisms in glucose regulation of MAL gene expression.
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Affiliation(s)
- Z Hu
- Department of Biology, Queens College and the Graduate School of CUNY, Flushing 11367, USA
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Sirenko OI, Ni B, Needleman RB. Purification and binding properties of the Mal63p activator of Saccharomyces cerevisiae. Curr Genet 1995; 27:509-16. [PMID: 7553934 DOI: 10.1007/bf00314440] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mal63p is a transcriptional activator for maltose fermentation in Saccharomyces cerevisiae. We have purified it to homogeneity from a yeast strain in which the MAL63 gene is under the control of the GAL1-GAL10 promoter. Purification included fractionation of a whole-cell extract by ion-exchange chromatography, chromatography using both non-specific DNA-affinity (calf thymus), and sequence-specific DNA-affinity chromatography. Mal63p activity was assayed by its binding to a fragment of the MAL61-MAL62 promoter, using both filter-binding and electrophoretic-mobility shift assays. DNase-I footprinting identified a new binding site (site 3) between the two previously known sites (sites 1 and 2). Mal63p is a dimer, and methylation-protection experiments identify the recognition motif as: c/a GC N9 c/a GC/g.
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Affiliation(s)
- O I Sirenko
- Wayne State University School of Medicine, Department of Biochemistry, Detroit, MI 48201, USA
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A carbon source-responsive promoter element necessary for activation of the isocitrate lyase gene ICL1 is common to genes of the gluconeogenic pathway in the yeast Saccharomyces cerevisiae. Mol Cell Biol 1994. [PMID: 8196607 DOI: 10.1128/mcb.14.6.3613] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The expression of yeast genes encoding gluconeogenic enzymes depends strictly on the carbon source available in the growth medium. We have characterized the control region of the isocitrate lyase gene ICL1, which is derepressed more than 200-fold after transfer of cells from fermentative to nonfermentative growth conditions. Deletion analysis of the ICL1 promoter led to the identification of an upstream activating sequence element, UASICL1 (5' CATTCATCCG 3'), necessary and sufficient for conferring carbon source-dependent regulation on a heterologous reporter gene. Similar sequence motifs were also found in the upstream regions of coregulated genes involved in gluconeogenesis. This carbon source-responsive element (CSRE) interacts with a protein factor, designated Ang1 (activator of nonfermentative growth), detectable only in extracts derived from derepressed cells. Gene activation mediated by the CSRE requires the positively acting derepression genes CAT1 (= SNF1 and CCR1) and CAT3 (= SNF4). In the respective mutants, Ang1-CSRE interaction was no longer observed under repressing or derepressing conditions. Since binding of Ang1 factor to the CSRE could be competed for by an upstream sequence derived from the fructose-1,6-bisphosphatase gene FBP1, we propose that the CSRE functions as a UAS element common to genes of the gluconeogenic pathway.
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Yao B, Sollitti P, Zhang X, Marmur J. Shared control of maltose induction and catabolite repression of the MAL structural genes in Saccharomyces. MOLECULAR & GENERAL GENETICS : MGG 1994; 243:622-30. [PMID: 8028578 DOI: 10.1007/bf00279571] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Maltose utilization in yeast requires the presence of any one of the five unlinked, homologous MAL loci. Transcription of the two structural genes MALT (permease) and MALS (maltase) is induced by maltose and catabolite-repressed by glucose. MAL6T and MAL6S share a common 5' intergenic sequence; deletion studies within this sequence revealed a bi-directionally functioning upstream activation sequence (UASM) consisting of four 11 bp homologous sites. Activation of these sites by the MALR protein results in the coordinate expression of MAL6T and MAL6S. The basal promoter activates MALS expression to a greater extent than MALT and is located in a region that overlaps UASM. Deletion of several subsites within the UASM has an asymmetric effect on MAL gene expression, having a greater affect on MALT than on MALS. Catabolite repression of MAL6T and MAL6S by glucose is controlled at several levels. Using disruption mutants, the positively acting MAL1R protein was also found to play a role in catabolite repression of MAL6T and MAL6S.
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Affiliation(s)
- B Yao
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
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Schöler A, Schüller HJ. A carbon source-responsive promoter element necessary for activation of the isocitrate lyase gene ICL1 is common to genes of the gluconeogenic pathway in the yeast Saccharomyces cerevisiae. Mol Cell Biol 1994; 14:3613-22. [PMID: 8196607 PMCID: PMC358729 DOI: 10.1128/mcb.14.6.3613-3622.1994] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The expression of yeast genes encoding gluconeogenic enzymes depends strictly on the carbon source available in the growth medium. We have characterized the control region of the isocitrate lyase gene ICL1, which is derepressed more than 200-fold after transfer of cells from fermentative to nonfermentative growth conditions. Deletion analysis of the ICL1 promoter led to the identification of an upstream activating sequence element, UASICL1 (5' CATTCATCCG 3'), necessary and sufficient for conferring carbon source-dependent regulation on a heterologous reporter gene. Similar sequence motifs were also found in the upstream regions of coregulated genes involved in gluconeogenesis. This carbon source-responsive element (CSRE) interacts with a protein factor, designated Ang1 (activator of nonfermentative growth), detectable only in extracts derived from derepressed cells. Gene activation mediated by the CSRE requires the positively acting derepression genes CAT1 (= SNF1 and CCR1) and CAT3 (= SNF4). In the respective mutants, Ang1-CSRE interaction was no longer observed under repressing or derepressing conditions. Since binding of Ang1 factor to the CSRE could be competed for by an upstream sequence derived from the fructose-1,6-bisphosphatase gene FBP1, we propose that the CSRE functions as a UAS element common to genes of the gluconeogenic pathway.
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Affiliation(s)
- A Schöler
- Institut für Mikrobiologie, Biochemie und Genetik, Universität Erlangen/Nürnberg, Germany
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