1
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Lee B, Hokamp K, Alhussain MM, Bamagoos AA, Fleming AB. The influence of flocculation upon global gene transcription in a yeast CYC8 mutant. Microb Genom 2024; 10:001216. [PMID: 38529898 PMCID: PMC10995634 DOI: 10.1099/mgen.0.001216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/29/2024] [Indexed: 03/27/2024] Open
Abstract
The transcriptome from a Saccharomyces cerevisiae tup1 deletion mutant was one of the first comprehensive yeast transcriptomes published. Subsequent transcriptomes from tup1 and cyc8 mutants firmly established the Tup1-Cyc8 complex as predominantly acting as a repressor of gene transcription. However, transcriptomes from tup1/cyc8 gene deletion or conditional mutants would all have been influenced by the striking flocculation phenotypes that these mutants display. In this study, we have separated the impact of flocculation from the transcriptome in a cyc8 conditional mutant to reveal those genes (i) subject solely to Cyc8p-dependent regulation, (ii) regulated by flocculation only and (iii) regulated by Cyc8p and further influenced by flocculation. We reveal a more accurate list of Cyc8p-regulated genes that includes newly identified Cyc8p-regulated genes that were masked by the flocculation phenotype and excludes genes which were indirectly influenced by flocculation and not regulated by Cyc8p. Furthermore, we show evidence that flocculation exerts a complex and potentially dynamic influence upon global gene transcription. These data should be of interest to future studies into the mechanism of action of the Tup1-Cyc8 complex and to studies involved in understanding the development of flocculation and its impact upon cell function.
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Affiliation(s)
- Brenda Lee
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Karsten Hokamp
- Department of Genetics, School of Genetics and Microbiology, Smurfit Institute, Trinity College Dublin, Dublin, Ireland
| | - Mohamed M. Alhussain
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Atif A. Bamagoos
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Alastair B. Fleming
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
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2
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Lee B, Church M, Hokamp K, Alhussain MM, Bamagoos AA, Fleming AB. Systematic analysis of tup1 and cyc8 mutants reveals distinct roles for TUP1 and CYC8 and offers new insight into the regulation of gene transcription by the yeast Tup1-Cyc8 complex. PLoS Genet 2023; 19:e1010876. [PMID: 37566621 PMCID: PMC10446238 DOI: 10.1371/journal.pgen.1010876] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 08/23/2023] [Accepted: 07/19/2023] [Indexed: 08/13/2023] Open
Abstract
The Tup1-Cyc8 complex in Saccharomyces cerevisiae was one of the first global co-repressors of gene transcription discovered. However, despite years of study, a full understanding of the contribution of Tup1p and Cyc8p to complex function is lacking. We examined TUP1 and CYC8 single and double deletion mutants and show that CYC8 represses more genes than TUP1, and that there are genes subject to (i) unique repression by TUP1 or CYC8, (ii) redundant repression by TUP1 and CYC8, and (iii) there are genes at which de-repression in a cyc8 mutant is dependent upon TUP1, and vice-versa. We also reveal that Tup1p and Cyc8p can make distinct contributions to commonly repressed genes most likely via specific interactions with different histone deacetylases. Furthermore, we show that Tup1p and Cyc8p can be found independently of each other to negatively regulate gene transcription and can persist at active genes to negatively regulate on-going transcription. Together, these data suggest that Tup1p and Cyc8p can associate with active and inactive genes to mediate distinct negative and positive regulatory roles when functioning within, and possibly out with the complex.
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Affiliation(s)
- Brenda Lee
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Michael Church
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Karsten Hokamp
- Department of Genetics, School of Genetics and Microbiology, Smurfit Institute, Trinity College Dublin, Dublin, Ireland
| | - Mohamed M. Alhussain
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Atif A. Bamagoos
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Alastair B. Fleming
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
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3
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Azizoğlu A, Loureiro C, Venetz J, Brent R. Autorepression-Based Conditional Gene Expression System in Yeast for Variation-Suppressed Control of Protein Dosage. Curr Protoc 2023; 3:e647. [PMID: 36708363 DOI: 10.1002/cpz1.647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Conditional control of gene expression allows an experimenter to investigate many aspects of a gene's function. In the model organism Saccharomyces cerevisiae, a number of methods to control gene expression are widely practiced, including induction by metabolites, small molecules, and even light. However, all current methods suffer from at least one of a set of drawbacks, including need for specialized growth conditions, leaky expression, or requirement of specialized equipment. Here we describe protocols using two transformations to construct strains that carry a new controller in which all these drawbacks are overcome. In these strains, the expression of a controlled gene of interest is repressed by the bacterial repressor TetR and induced by anhydrotetracycline. TetR also regulates its own expression, creating an autorepression loop. This autorepression allows tight control of gene expression and protein dosage with low cell-to-cell variation in expression. A second repressor, TetR-Tup1, prevents any leaky expression. We also present a protocol showing a particular workhorse application of such strains to generate synchronized cell populations. We turn off expression of the cell cycle regulator CDC20 completely, arresting the cell population, and then we turn it back on so that the synchronized cells resume cell cycle progression. This control system can be applied to any endogenous or exogenous gene for precise expression. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Generating a parent WTC846 strain Basic Protocol 2: Generating a WTC846 strain with controlled expression of the targeted gene Alternate Protocol: CRISPR-mediated promoter replacement Basic Protocol 3: Cell cycle synchronization/arrest and release using the WTC846- K3 ::CDC20 strain.
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Affiliation(s)
- Aslı Azizoğlu
- Computational Systems Biology and Swiss Institute of Bioinformatics, ETH Zurich, Basel, Switzerland
| | - Cristina Loureiro
- Computational Systems Biology and Swiss Institute of Bioinformatics, ETH Zurich, Basel, Switzerland
| | - Jonathan Venetz
- Computational Systems Biology and Swiss Institute of Bioinformatics, ETH Zurich, Basel, Switzerland
| | - Roger Brent
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington
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4
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Tup1 is critical for transcriptional repression in Quiescence in S. cerevisiae. PLoS Genet 2022; 18:e1010559. [PMID: 36542663 DOI: 10.1371/journal.pgen.1010559] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/05/2023] [Accepted: 12/07/2022] [Indexed: 12/24/2022] Open
Abstract
Upon glucose starvation, S. cerevisiae shows a dramatic alteration in transcription, resulting in wide-scale repression of most genes and activation of some others. This coincides with an arrest of cellular proliferation. A subset of such cells enters quiescence, a reversible non-dividing state. Here, we demonstrate that the conserved transcriptional corepressor Tup1 is critical for transcriptional repression after glucose depletion. We show that Tup1-Ssn6 binds new targets upon glucose depletion, where it remains as the cells enter the G0 phase of the cell cycle. In addition, we show that Tup1 represses a variety of glucose metabolism and transport genes. We explored how Tup1 mediated repression is accomplished and demonstrated that Tup1 coordinates with the Rpd3L complex to deacetylate H3K23. We found that Tup1 coordinates with Isw2 to affect nucleosome positions at glucose transporter HXT family genes during G0. Finally, microscopy revealed that a quarter of cells with a Tup1 deletion contain multiple DAPI puncta. Taken together, these findings demonstrate the role of Tup1 in transcriptional reprogramming in response to environmental cues leading to the quiescent state.
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5
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Ma QZ, Wu HY, Xie SP, Zhao BS, Yin XM, Ding SL, Guo YS, Xu C, Zang R, Geng YH, Zhang M. BsTup1 is required for growth, conidiogenesis, stress response and pathogenicity of Bipolaris sorokiniana. Int J Biol Macromol 2022; 220:721-732. [PMID: 35981683 DOI: 10.1016/j.ijbiomac.2022.07.250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 11/05/2022]
Abstract
Tup1, a conserved transcriptional repressor, plays a critical role in the growth and development of fungi. Here, we identified a BsTup1 gene from the plant pathogenic fungus Bipolaris sorokiniana. The expression of BsTup1 showed a more than three-fold increase during the conidial stage compared with mycelium stage. Deletion of BsTup1 led to decrease hyphal growth and defect in conidia formation. A significant difference was detected in osmotic, oxidative, or cell wall stress responses between the WT and ΔBsTup1 strains. Pathogenicity assays showed that virulence of the ΔBsTup1 mutant was dramatically decreased on wheat and barely leaves. Moreover, it was observed that hyphal tips of the mutants could not form appressorium-like structures on the inner epidermis of onion and barley coleoptile. Yeast two-hybrid assays indicated that BsTup1 could interact with the BsSsn6. RNAseq revealed significant transcriptional changes in the ΔBsTup1 mutant with 2369 genes down-regulated and 2962 genes up-regulated. In these genes, we found that a subset of genes involved in fungal growth, sporulation, cell wall integrity, osmotic stress, oxidation stress, and pathogenicity, which were misregulated in the ΔBsTup1 mutant. These data revealed that BsTup1 has multiple functions in fungal growth, development, stress response and pathogenesis in B. sorokiniana.
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Affiliation(s)
- Qing-Zhou Ma
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Hai-Yan Wu
- Analytical Instrument Center, Henan Agricultural University, Zhengzhou 450002, China
| | - Shun-Pei Xie
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Bing-Sen Zhao
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Xin-Ming Yin
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Sheng-Li Ding
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Ya-Shuang Guo
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Chao Xu
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Rui Zang
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Yue-Hua Geng
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China.
| | - Meng Zhang
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China.
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6
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Parnell EJ, Parnell TJ, Stillman DJ. Genetic analysis argues for a coactivator function for the Saccharomyces cerevisiae Tup1 corepressor. Genetics 2021; 219:6329640. [PMID: 34849878 DOI: 10.1093/genetics/iyab120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 07/20/2021] [Indexed: 11/14/2022] Open
Abstract
The Tup1-Cyc8 corepressor complex of Saccharomyces cerevisiae is recruited to promoters by DNA-binding proteins to repress transcription of genes, including the a-specific mating-type genes. We report here a tup1(S649F) mutant that displays mating irregularities and an α-predominant growth defect. RNA-Seq and ChIP-Seq were used to analyze gene expression and Tup1 occupancy changes in mutant vs wild type in both a and α cells. Increased Tup1(S649F) occupancy tended to occur upstream of upregulated genes, whereas locations with decreased occupancy usually did not show changes in gene expression, suggesting this mutant not only loses corepressor function but also behaves as a coactivator. Based upon studies demonstrating a dual role of Tup1 in both repression and activation, we postulate that the coactivator function of Tup1(S649F) results from diminished interaction with repressor proteins, including α2. We also found that large changes in mating-type-specific gene expression between a and α or between mutant and wild type were not easily explained by the range of Tup1 occupancy levels within their promoters, as predicted by the classic model of a-specific gene repression by Tup1. Most surprisingly, we observed Tup1 occupancy upstream of the a-specific gene MFA2 and the α-specific gene MF(ALPHA)1 in cells in which each gene was expressed rather than repressed. These results, combined with the identification of additional mating-related genes upregulated in the tup1(S649F) α strain, illustrate that the role of Tup1 in distinguishing mating types in yeast appears to be both more comprehensive and more nuanced than previously appreciated.
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Affiliation(s)
- Emily J Parnell
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, UT 84112, USA
| | - Timothy J Parnell
- Bioinformatics Shared Resource, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - David J Stillman
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, UT 84112, USA
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7
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Azizoglu A, Brent R, Rudolf F. A precisely adjustable, variation-suppressed eukaryotic transcriptional controller to enable genetic discovery. eLife 2021; 10:69549. [PMID: 34342575 PMCID: PMC8421071 DOI: 10.7554/elife.69549] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/02/2021] [Indexed: 11/13/2022] Open
Abstract
Conditional expression of genes and observation of phenotype remain central to biological discovery. Current methods enable either on/off or imprecisely controlled graded gene expression. We developed a 'well-tempered' controller, WTC846, for precisely adjustable, graded, growth condition independent expression of genes in Saccharomyces cerevisiae. Controlled genes are expressed from a strong semisynthetic promoter repressed by the prokaryotic TetR, which also represses its own synthesis; with basal expression abolished by a second, 'zeroing' repressor. The autorepression loop lowers cell-to-cell variation while enabling precise adjustment of protein expression by a chemical inducer. WTC846 allelic strains in which the controller replaced the native promoters recapitulated known null phenotypes (CDC42, TPI1), exhibited novel overexpression phenotypes (IPL1), showed protein dosage-dependent growth rates and morphological phenotypes (CDC28, TOR2, PMA1 and the hitherto uncharacterized PBR1), and enabled cell cycle synchronization (CDC20). WTC846 defines an 'expression clamp' allowing protein dosage to be adjusted by the experimenter across the range of cellular protein abundances, with limited variation around the setpoint.
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Affiliation(s)
| | - Roger Brent
- Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
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8
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Leydon AR, Wang W, Gala HP, Gilmour S, Juarez-Solis S, Zahler ML, Zemke JE, Zheng N, Nemhauser JL. Repression by the Arabidopsis TOPLESS corepressor requires association with the core mediator complex. eLife 2021; 10:66739. [PMID: 34075876 PMCID: PMC8203292 DOI: 10.7554/elife.66739] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 05/31/2021] [Indexed: 02/06/2023] Open
Abstract
The plant corepressor TOPLESS (TPL) is recruited to a large number of loci that are selectively induced in response to developmental or environmental cues, yet the mechanisms by which it inhibits expression in the absence of these stimuli are poorly understood. Previously, we had used the N-terminus of Arabidopsis thaliana TPL to enable repression of a synthetic auxin response circuit in Saccharomyces cerevisiae (yeast). Here, we leveraged the yeast system to interrogate the relationship between TPL structure and function, specifically scanning for repression domains. We identified a potent repression domain in Helix 8 located within the CRA domain, which directly interacted with the Mediator middle module subunits Med21 and Med10. Interactions between TPL and Mediator were required to fully repress transcription in both yeast and plants. In contrast, we found that multimer formation, a conserved feature of many corepressors, had minimal influence on the repression strength of TPL.
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Affiliation(s)
| | - Wei Wang
- Department of Pharmacology, Seattle, United States
| | - Hardik P Gala
- Department of Biology, University of Washington, Seattle, United States
| | - Sabrina Gilmour
- Department of Biology, University of Washington, Seattle, United States
| | | | - Mollye L Zahler
- Department of Biology, University of Washington, Seattle, United States
| | - Joseph E Zemke
- Department of Biology, University of Washington, Seattle, United States
| | - Ning Zheng
- Department of Pharmacology, Seattle, United States.,Howard Hughes Medical Institute, University of Washington, Seattle, United States
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9
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Saik NO, Park N, Ptak C, Adames N, Aitchison JD, Wozniak RW. Recruitment of an Activated Gene to the Yeast Nuclear Pore Complex Requires Sumoylation. Front Genet 2020; 11:174. [PMID: 32211027 PMCID: PMC7067905 DOI: 10.3389/fgene.2020.00174] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/13/2020] [Indexed: 01/10/2023] Open
Abstract
In addition to their role in regulating transport across the nuclear envelope, increasing evidence suggests nuclear pore complexes (NPCs) function in regulating gene expression. For example, the induction of certain genes (e.g., yeast INO1) is accompanied by their movement from the nuclear interior to NPCs. As sumoylation has been linked to the regulation of chromatin spatial organization and transcriptional activity, we investigated the role of sumoylation in the expression and NPC recruitment of the INO1 gene. We observed that induction of INO1 is accompanied by both increased and decreased sumoylation of proteins associated with specific regions along the INO1 locus. Furthermore, we show that the E3 ligase Siz2/Nfi1 is required for targeting the INO1 locus to the NPC where it interacts with the SUMO isopeptidase Ulp1. Our data suggest that this interaction is required for both the association of INO1 with the NPC and for its normal expression. These results imply that sumoylation is a key regulator of INO1 targeting to the NPC, and a cycle of sumoylation and NPC-associated desumoylation events contribute to the regulation of INO1 expression.
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Affiliation(s)
- Natasha O Saik
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada
| | - Nogi Park
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada.,Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States
| | - Christopher Ptak
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada
| | - Neil Adames
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada.,New Culture, San Francisco, CA, United States
| | - John D Aitchison
- Seattle Children's Research Institute, Seattle, WA, United States
| | - Richard W Wozniak
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada
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10
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Lubelsky Y, Shaul Y. Recruitment of the protein phosphatase-1 catalytic subunit to promoters by the dual-function transcription factor RFX1. Biochem Biophys Res Commun 2019; 509:1015-1020. [PMID: 30654936 DOI: 10.1016/j.bbrc.2019.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 01/03/2019] [Indexed: 01/06/2023]
Abstract
RFX proteins are a family of conserved DNA binding proteins involved in various, essential cellular and developmental processes. RFX1 is a ubiquitously expressed, dual-activity transcription factor capable of both activation and repression of target genes. The exact mechanism by which RFX1 regulates its target is not known yet. In this work, we show that the C-terminal repression domain of RFX1 interacts with the Serine/Threonine protein phosphatase PP1c, and that interaction with RFX1 can target PP1c to specific sites in the genome. Given that PP1c was shown to de-phosphorylate several transcription factors, as well as the regulatory C-terminal domain of RNA Polymerase II the recruitment of PP1c to promoters may be a mechanism by which RFX1 regulates the target genes.
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Affiliation(s)
- Yoav Lubelsky
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| | - Yosef Shaul
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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11
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Histone Chaperone Asf1 Is Required for the Establishment of Repressive Chromatin in Schizosaccharomyces pombe fbp1 Gene Repression. Mol Cell Biol 2018; 38:MCB.00194-18. [PMID: 29967244 DOI: 10.1128/mcb.00194-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 06/23/2018] [Indexed: 11/20/2022] Open
Abstract
The arrangement of nucleosomes in chromatin plays a role in transcriptional regulation by restricting the accessibility of transcription factors and RNA polymerase II to cis-acting elements and promoters. For gene activation, the chromatin structure is altered to an open configuration. The mechanism for this process has been extensively analyzed. However, the mechanism by which repressive chromatin is reconstituted to terminate transcription has not been fully elucidated. Here, we investigated the mechanisms by which chromatin is reconstituted in the fission yeast Schizosaccharomyces pombefbp1 gene, which is robustly induced upon glucose starvation but tightly repressed under glucose-rich conditions. We found that the chromatin structure in the region upstream from fbp1 is closed by a two-step process. When cells are returned to glucose-rich medium following glucose starvation, changes in the nucleosome pattern alter the chromatin configuration at the transcription factor binding site to an inaccessible state, after which the nucleosome density upstream from fbp1 gradually increases via histone loading. Interestingly, this histone loading was observed in the absence of the Tup family corepressors Tup11 and Tup12. Analysis of strains carrying either gene disruptions or mutations affecting nine fission yeast histone chaperone genes demonstrated that the histone chaperone Asf1 induces nucleosome loading during glucose repression. These data establish a previously unappreciated chromatin reconstitution mechanism in fbp1 repression.
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12
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Lin X, Yu AQ, Zhang CY, Pi L, Bai XW, Xiao DG. Functional analysis of the global repressor Tup1 for maltose metabolism in Saccharomyces cerevisiae: different roles of the functional domains. Microb Cell Fact 2017; 16:194. [PMID: 29121937 PMCID: PMC5679332 DOI: 10.1186/s12934-017-0806-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 10/31/2017] [Indexed: 11/15/2022] Open
Abstract
Background Tup1 is a general transcriptional repressor of diverse gene families coordinately controlled by glucose repression, mating type, and other mechanisms in Saccharomyces cerevisiae. Several functional domains of Tup1 have been identified, each of which has differing effects on transcriptional repression. In this study, we aim to investigate the role of Tup1 and its domains in maltose metabolism of industrial baker’s yeast. To this end, a battery of in-frame truncations in the TUP1 gene coding region were performed in the industrial baker’s yeasts with different genetic background, and the maltose metabolism, leavening ability, MAL gene expression levels, and growth characteristics were investigated. Results The results suggest that the TUP1 gene is essential to maltose metabolism in industrial baker’s yeast. Importantly, different domains of Tup1 play different roles in glucose repression and maltose metabolism of industrial baker’s yeast cells. The Ssn6 interaction, N-terminal repression and C-terminal repression domains might play roles in the regulation of MAL transcription by Tup1 for maltose metabolism of baker’s yeast. The WD region lacking the first repeat could influence the regulation of maltose metabolism directly, rather than indirectly through glucose repression. Conclusions These findings lay a foundation for the optimization of industrial baker’s yeast strains for accelerated maltose metabolism and facilitate future research on glucose repression in other sugar metabolism. Electronic supplementary material The online version of this article (10.1186/s12934-017-0806-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xue Lin
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.,College of Food Science and Technology, Hainan University, Haikou, 570228, China
| | - Ai-Qun Yu
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China
| | - Cui-Ying Zhang
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
| | - Li Pi
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China
| | - Xiao-Wen Bai
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China
| | - Dong-Guang Xiao
- Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
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13
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Asada R, Umeda M, Adachi A, Senmatsu S, Abe T, Iwasaki H, Ohta K, Hoffman CS, Hirota K. Recruitment and delivery of the fission yeast Rst2 transcription factor via a local genome structure counteracts repression by Tup1-family corepressors. Nucleic Acids Res 2017; 45:9361-9371. [PMID: 28934464 PMCID: PMC5766161 DOI: 10.1093/nar/gkx555] [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: 03/16/2017] [Accepted: 06/14/2017] [Indexed: 12/12/2022] Open
Abstract
Transcription factors (TFs) determine the transcription activity of target genes and play a central role in controlling the transcription in response to various environmental stresses. Three dimensional genome structures such as local loops play a fundamental role in the regulation of transcription, although the link between such structures and the regulation of TF binding to cis-regulatory elements remains to be elucidated. Here, we show that during transcriptional activation of the fission yeast fbp1 gene, binding of Rst2 (a critical C2H2 zinc-finger TF) is mediated by a local loop structure. During fbp1 activation, Rst2 is first recruited to upstream-activating sequence 1 (UAS1), then it subsequently binds to UAS2 (a critical cis-regulatory site located approximately 600 base pairs downstream of UAS1) through a loop structure that brings UAS1 and UAS2 into spatially close proximity. Tup11/12 (the Tup-family corepressors) suppress direct binding of Rst2 to UAS2, but this suppression is counteracted by the recruitment of Rst2 at UAS1 and following delivery to UAS2 through a loop structure. These data demonstrate a previously unappreciated mechanism for the recruitment and expansion of TF-DNA interactions within a promoter mediated by local three-dimensional genome structures and for timely TF-binding via counteractive regulation by the Tup-family corepressors.
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Affiliation(s)
- Ryuta Asada
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Miki Umeda
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Akira Adachi
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Satoshi Senmatsu
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Takuya Abe
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
| | - Hiroshi Iwasaki
- Cell Biology Unit, Institute of Innovative Research, Tokyo Institute of Technology M6-11, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Kunihiro Ohta
- Department of Life Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan.,Universal Biology Institute, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | | | - Kouji Hirota
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Minamiosawa 1-1, Hachioji-shi, Tokyo 192-0397, Japan
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14
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Church M, Smith KC, Alhussain MM, Pennings S, Fleming AB. Sas3 and Ada2(Gcn5)-dependent histone H3 acetylation is required for transcription elongation at the de-repressed FLO1 gene. Nucleic Acids Res 2017; 45:4413-4430. [PMID: 28115623 PMCID: PMC5416777 DOI: 10.1093/nar/gkx028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/19/2017] [Indexed: 01/12/2023] Open
Abstract
The Saccharomyces cerevisiae FLO1 gene encodes a cell wall protein that imparts cell-cell adhesion. FLO1 transcription is regulated via the antagonistic activities of the Tup1-Cyc8 co-repressor and Swi-Snf co-activator complexes. Tup1-Cyc8 represses transcription through the organization of strongly positioned, hypoacetylated nucleosomes across gene promoters. Swi-Snf catalyzes remodeling of these nucleosomes in a mechanism involving histone acetylation that is poorly understood. Here, we show that FLO1 de-repression is accompanied by Swi-Snf recruitment, promoter histone eviction and Sas3 and Ada2(Gcn5)-dependent histone H3K14 acetylation. In the absence of H3K14 acetylation, Swi-Snf recruitment and histone eviction proceed, but transcription is reduced, suggesting these processes, while essential, are not sufficient for de-repression. Further analysis in the absence of H3K14 acetylation reveals RNAP II recruitment at the FLO1 promoter still occurs, but RNAP II is absent from the gene-coding region, demonstrating Sas3 and Ada2-dependent histone H3 acetylation is required for transcription elongation. Analysis of the transcription kinetics at other genes reveals shared mechanisms coupled to a distinct role for histone H3 acetylation, essential at FLO1, downstream of initiation. We propose histone H3 acetylation in the coding region provides rate-limiting control during the transition from initiation to elongation which dictates whether the gene is permissive for transcription.
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Affiliation(s)
- Michael Church
- School of Genetics and Microbiology, University of Dublin, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Kim C Smith
- School of Genetics and Microbiology, University of Dublin, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Mohamed M Alhussain
- School of Genetics and Microbiology, University of Dublin, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Sari Pennings
- Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Alastair B Fleming
- School of Genetics and Microbiology, University of Dublin, Trinity College Dublin, College Green, Dublin 2, Ireland
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15
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McKnight JN, Tsukiyama T, Bowman GD. Sequence-targeted nucleosome sliding in vivo by a hybrid Chd1 chromatin remodeler. Genome Res 2016; 26:693-704. [PMID: 26993344 PMCID: PMC4864466 DOI: 10.1101/gr.199919.115] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 03/14/2016] [Indexed: 01/15/2023]
Abstract
ATP-dependent chromatin remodelers regulate chromatin dynamics by modifying nucleosome positions and occupancy. DNA-dependent processes such as replication and transcription rely on chromatin to faithfully regulate DNA accessibility, yet how chromatin remodelers achieve well-defined nucleosome positioning in vivo is poorly understood. Here, we report a simple method for site-specifically altering nucleosome positions in live cells. By fusing the Chd1 remodeler to the DNA binding domain of the Saccharomyces cerevisiae Ume6 repressor, we have engineered a fusion remodeler that selectively positions nucleosomes on top of adjacent Ume6 binding motifs in a highly predictable and reproducible manner. Positioning of nucleosomes by the fusion remodeler recapitulates closed chromatin structure at Ume6-sensitive genes analogous to the endogenous Isw2 remodeler. Strikingly, highly precise positioning of single founder nucleosomes by either chimeric Chd1-Ume6 or endogenous Isw2 shifts phased chromatin arrays in cooperation with endogenous chromatin remodelers. Our results demonstrate feasibility of engineering precise nucleosome rearrangements through sequence-targeted chromatin remodeling and provide insight into targeted action and cooperation of endogenous chromatin remodelers in vivo.
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Affiliation(s)
- Jeffrey N McKnight
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Toshio Tsukiyama
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Gregory D Bowman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA
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16
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Vega M, Riera A, Fernández-Cid A, Herrero P, Moreno F. Hexokinase 2 Is an Intracellular Glucose Sensor of Yeast Cells That Maintains the Structure and Activity of Mig1 Protein Repressor Complex. J Biol Chem 2016; 291:7267-85. [PMID: 26865637 DOI: 10.1074/jbc.m115.711408] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Indexed: 11/06/2022] Open
Abstract
Hexokinase 2 (Hxk2) fromSaccharomyces cerevisiaeis a bi-functional enzyme, being both a catalyst in the cytosol and an important regulator of the glucose repression signal in the nucleus. Despite considerable recent progress, little is known about the regulatory mechanism that controls nuclear Hxk2 association with theSUC2promoter chromatin and how this association is necessary forSUC2gene repression. Our data indicate that in theSUC2promoter context, Hxk2 functions through a variety of structurally unrelated factors, mainly the DNA-binding Mig1 and Mig2 repressors and the regulatory Snf1 and Reg1 factors. Hxk2 sustains the repressor complex architecture maintaining transcriptional repression at theSUC2gene. Using chromatin immunoprecipitation assays, we discovered that the Hxk2 in its open configuration, at low glucose conditions, leaves the repressor complex that induces its dissociation and promotesSUC2gene expression. In high glucose conditions, Hxk2 adopts a close conformation that promotes Hxk2 binding to the Mig1 protein and the reassembly of theSUC2repressor complex. Additional findings highlight the possibility that Hxk2 constitutes an intracellular glucose sensor that operates by changing its conformation in response to cytoplasmic glucose levels that regulate its interaction with Mig1 and thus its recruitment to the repressor complex of theSUC2promoter. Thus, our data indicate that Hxk2 is more intimately involved in gene regulation than previously thought.
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Affiliation(s)
- Montserrat Vega
- From the Department of Biochemistry and Molecular Biology, University of Oviedo, 33006-Oviedo, Spain
| | - Alberto Riera
- From the Department of Biochemistry and Molecular Biology, University of Oviedo, 33006-Oviedo, Spain
| | - Alejandra Fernández-Cid
- From the Department of Biochemistry and Molecular Biology, University of Oviedo, 33006-Oviedo, Spain
| | - Pilar Herrero
- From the Department of Biochemistry and Molecular Biology, University of Oviedo, 33006-Oviedo, Spain
| | - Fernando Moreno
- From the Department of Biochemistry and Molecular Biology, University of Oviedo, 33006-Oviedo, Spain
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17
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Antagonistic controls of chromatin and mRNA start site selection by Tup family corepressors and the CCAAT-binding factor. Mol Cell Biol 2014; 35:847-55. [PMID: 25535331 DOI: 10.1128/mcb.00924-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Tup family corepressors contribute to critical cellular responses, such as the stress response and differentiation, presumably by inducing repressive chromatin, though the precise repression mechanism remains to be elucidated. The Schizosaccharomyces pombe fission yeast Tup family corepressors Tup11 and Tup12 (Tup11/12), which are orthologs of Tup1 in Saccharomyces cerevisiae budding yeast and Groucho in Drosophila, negatively control chromatin and the transcriptional activity of some stress-responsive genes. Here, we demonstrate that Tup11/12 repress transcription of a gluconeogenesis gene, fbp1⁺, by three distinct mechanisms. First, Tup11/12 inhibit chromatin remodeling in the fbp1⁺ promoter region where the Atf1 and Rst2 transcriptional activators bind. Second, they repress the formation of an open chromatin configuration at the fbp1⁺ TATA box. Third, they repress mRNA transcription per se by regulating basic transcription factors. These inhibitory actions of Tup11/12 are antagonized by three different types of transcriptional activators: CREB/ATF-type Atf1, C₂H₂zinc finger-type Rst2, and CBF/NF-Y-type Php5 proteins. We also found that impaired chromatin remodeling and fbp1⁺ mRNA transcription in php5Δ strains are rescued by the double deletions of tup11⁺ and tup12⁺, although the distribution of the transcription start sites becomes broader than that in wild-type cells. These data reveal a new mechanism of precise determination of the mRNA start site by Tup family corepressors and CBF/NF-Y proteins.
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18
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Sumoylation and transcription regulation at nuclear pores. Chromosoma 2014; 124:45-56. [PMID: 25171917 PMCID: PMC4339684 DOI: 10.1007/s00412-014-0481-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/16/2014] [Accepted: 07/17/2014] [Indexed: 01/22/2023]
Abstract
Increasing evidence indicates that besides promoters, enhancers, and epigenetic modifications, nuclear organization is another parameter contributing to optimal control of gene expression. Although differences between species exist, the influence of gene positioning on expression seems to be a conserved feature from yeast to Drosophila and mammals. The nuclear periphery is one of the nuclear compartments implicated in gene regulation. It consists of the nuclear envelope (NE) and the nuclear pore complexes (NPC), which have distinct roles in the control of gene expression. The NPC has recently been shown to tether proteins involved in the sumoylation pathway. Here, we will focus on the importance of gene positioning and NPC-linked sumoylation/desumoylation in transcription regulation. We will mainly discuss observations made in the yeast Saccharomyces cerevisiae model system and highlight potential parallels in metazoan species.
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19
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Fleming AB, Beggs S, Church M, Tsukihashi Y, Pennings S. The yeast Cyc8-Tup1 complex cooperates with Hda1p and Rpd3p histone deacetylases to robustly repress transcription of the subtelomeric FLO1 gene. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:1242-55. [PMID: 25106892 PMCID: PMC4316177 DOI: 10.1016/j.bbagrm.2014.07.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/28/2014] [Accepted: 07/29/2014] [Indexed: 12/02/2022]
Abstract
We demonstrate that the yeast flocculation gene, FLO1, is representative of a distinct subset of subtelomeric genes that are robustly repressed by the Cyc8–Tup1 complex. We have examined Cyc8–Tup1 localisation, histone acetylation and long-range chromatin remodelling within the extensive FLO1 upstream region. We show that Cyc8–Tup1 is localised in a DNase I hypersensitive site within an ordered array of strongly positioned nucleosomes around − 700 base pairs upstream of the transcription start site. In cyc8 deletion mutant strains, Tup1p localisation is absent, with concomitant histone hyperacetylation of adjacent regions at the FLO1 promoter. This is accompanied by extensive histone depletion across the upstream region and gene activation. The yeast histone deacetylases, Hda1p and Rpd3p, occupy the repressed FLO1 promoter region in a Cyc8–Tup1 dependent manner and coordinate histone deacetylation, nucleosome stabilisation and gene repression. Moreover, we show that the ATP-dependent chromatin remodelling complex Swi–Snf occupies the site vacated by Cyc8–Tup1 in a cyc8 mutant. These data suggest that distinctly bound Cyc8–Tup1 cooperates with Hda1p and Rpd3p to establish or maintain an extensive array of strongly positioned, deacetylated nucleosomes over the FLO1 promoter and upstream region which inhibit histone acetylation, block Swi–Snf binding and prevent transcription. Cyc8–Tup1 repression activity is enriched at chromosome subtelomeric regions. The subtelomeric FLO1 gene is subject to chromatin-mediated repression by Cyc8–Tup1. Cyc8–Tup1 promotes long-range nucleosome positioning and histone deacetylation. Hda1p and Rpd3p cooperate with Cyc8–Tup1 to facilitate this repressive chromatin. Swi–Snf directs extensive nucleosome remodelling when Cyc8–Tup1 is absent.
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Affiliation(s)
- Alastair B Fleming
- School of Genetics and Microbiology, Trinity College Dublin, College Green, Dublin 2, Ireland; School of Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK.
| | - Suzanne Beggs
- School of Genetics and Microbiology, Trinity College Dublin, College Green, Dublin 2, Ireland
| | - Michael Church
- School of Genetics and Microbiology, Trinity College Dublin, College Green, Dublin 2, Ireland
| | | | - Sari Pennings
- School of Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK; Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
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20
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Ruger-Herreros C, Gil-Sánchez MDM, Sancar G, Brunner M, Corrochano LM. Alteration of light-dependent gene regulation by the absence of the RCO-1/RCM-1 repressor complex in the fungus Neurospora crassa. PLoS One 2014; 9:e95069. [PMID: 24747913 PMCID: PMC3991626 DOI: 10.1371/journal.pone.0095069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 03/23/2014] [Indexed: 12/04/2022] Open
Abstract
The activation of transcription by light in the fungus Neurospora crassa requires the White Collar Complex (WCC), a photoreceptor and transcription factor complex. After light reception two WCCs interact and bind the promoters of light-regulated genes to activate transcription. This process is regulated by VVD, a small photoreceptor that disrupts the interaction between WCCs and leads to a reduction in transcription after long exposures to light. The N. crassa RCO-1/RCM-1 repressor complex is the homolog of the Tup1-Ssn6 repressor complex in yeast, and its absence modifies photoadaptation. We show that the absence of the RCO-1/RCM-1 repressor complex leads to several alterations in transcription that are gene-specific: an increase in the accumulation of mRNAs in the dark, a repression of transcription, and a derepression of transcription after long exposures to light. The absence of the RCO-1/RCM-1 repressor complex leads to lower VVD levels that are available for the regulation of the activity of the WCC. The reduction in the amount of VVD results in increased WCC binding to the promoters of light-regulated genes in the dark and after long exposures to light, leading to the modification of photoadaptation that has been observed in rco-1 and rcm-1 mutants. Our results show that the photoadaptation phenotype of mutants in the RCO-1/RCM-1 repressor complex is, at least in part, an indirect consequence of the reduction of vvd transcription, and the resulting modification in the regulation of transcription by the WCC.
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Affiliation(s)
| | | | - Gencer Sancar
- Biochemistry Center, University of Heidelberg, Heidelberg, Germany
| | - Michael Brunner
- Biochemistry Center, University of Heidelberg, Heidelberg, Germany
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21
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Gonzalez D, Hamidi N, Del Sol R, Benschop JJ, Nancy T, Li C, Francis L, Tzouros M, Krijgsveld J, Holstege FCP, Conlan RS. Suppression of Mediator is regulated by Cdk8-dependent Grr1 turnover of the Med3 coactivator. Proc Natl Acad Sci U S A 2014; 111:2500-5. [PMID: 24550274 PMCID: PMC3932902 DOI: 10.1073/pnas.1307525111] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mediator, an evolutionary conserved large multisubunit protein complex with a central role in regulating RNA polymerase II-transcribed genes, serves as a molecular switchboard at the interface between DNA binding transcription factors and the general transcription machinery. Mediator subunits include the Cdk8 module, which has both positive and negative effects on activator-dependent transcription through the activity of the cyclin-dependent kinase Cdk8, and the tail module, which is required for positive and negative regulation of transcription, correct preinitiation complex formation in basal and activated transcription, and Mediator recruitment. Currently, the molecular mechanisms governing Mediator function remain largely undefined. Here we demonstrate an autoregulatory mechanism used by Mediator to repress transcription through the activity of distinct components of different modules. We show that the function of the tail module component Med3, which is required for transcription activation, is suppressed by the kinase activity of the Cdk8 module. Med3 interacts with, and is phosphorylated by, Cdk8; site-specific phosphorylation triggers interaction with and degradation by the Grr1 ubiquitin ligase, thereby preventing transcription activation. This active repression mechanism involving Grr1-dependent ubiquitination of Med3 offers a rationale for the substoichiometric levels of the tail module that are found in purified Mediator and the corresponding increase in tail components seen in cdk8 mutants.
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Affiliation(s)
- Deyarina Gonzalez
- College of Medicine, Swansea University, Swansea, Wales SA2 8PP, United Kingdom
| | - Nurul Hamidi
- College of Medicine, Swansea University, Swansea, Wales SA2 8PP, United Kingdom
| | - Ricardo Del Sol
- College of Medicine, Swansea University, Swansea, Wales SA2 8PP, United Kingdom
| | - Joris J. Benschop
- Molecular Cancer Research, University Medical Centre Utrecht, 3508 AB, Utrecht, The Netherlands
| | - Thomas Nancy
- College of Medicine, Swansea University, Swansea, Wales SA2 8PP, United Kingdom
| | - Chao Li
- College of Medicine, Swansea University, Swansea, Wales SA2 8PP, United Kingdom
- Suzhou School of Nano-Science and Nano-Engineering, X’ian Jaotong University, Suzhou Industrial Park 215123, People’s Republic of China
| | - Lewis Francis
- College of Medicine, Swansea University, Swansea, Wales SA2 8PP, United Kingdom
| | - Manuel Tzouros
- Translational Technologies and Bioinformatics, Pharma Research and Early Development, F. Hoffmann-La Roche Ltd., 4070 Basel, Switzerland; and
| | - Jeroen Krijgsveld
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Frank C. P. Holstege
- Molecular Cancer Research, University Medical Centre Utrecht, 3508 AB, Utrecht, The Netherlands
| | - R. Steven Conlan
- College of Medicine, Swansea University, Swansea, Wales SA2 8PP, United Kingdom
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22
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Texari L, Dieppois G, Vinciguerra P, Contreras MP, Groner A, Letourneau A, Stutz F. The nuclear pore regulates GAL1 gene transcription by controlling the localization of the SUMO protease Ulp1. Mol Cell 2013; 51:807-18. [PMID: 24074957 DOI: 10.1016/j.molcel.2013.08.047] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 07/17/2013] [Accepted: 08/20/2013] [Indexed: 12/15/2022]
Abstract
Transcription activation of some yeast genes correlates with their repositioning to the nuclear pore complex (NPC). The NPC-bound Mlp1 and Mlp2 proteins have been shown to associate with the GAL1 gene promoter and to maintain Ulp1, a key SUMO protease, at the NPC. Here, we show that the release of Ulp1 from the NPC increases the kinetics of GAL1 derepression, whereas artificial NPC anchoring of Ulp1 in the Δmlp1/2 strain restores normal GAL1 regulation. Moreover, artificial tethering of the Ulp1 catalytic domain to the GAL1 locus enhances the derepression kinetics. Our results also indicate that Ulp1 modulates the sumoylation state of Tup1 and Ssn6, two regulators of glucose-repressed genes, and that a loss of Ssn6 sumoylation correlates with an increase in GAL1 derepression kinetics. Altogether, our data highlight a role for the NPC-associated SUMO protease Ulp1 in regulating the sumoylation of gene-bound transcription regulators, positively affecting transcription kinetics in the context of the NPC.
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Affiliation(s)
- Lorane Texari
- Department of Cell Biology, NCCR Frontiers in Genetics, iGE3, University of Geneva, Geneva 1211, Switzerland
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23
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Chen K, Wilson MA, Hirsch C, Watson A, Liang S, Lu Y, Li W, Dent SYR. Stabilization of the promoter nucleosomes in nucleosome-free regions by the yeast Cyc8-Tup1 corepressor. Genome Res 2012; 23:312-22. [PMID: 23124522 PMCID: PMC3561872 DOI: 10.1101/gr.141952.112] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The yeast Cyc8 (also known as Ssn6)–Tup1 complex regulates gene expression through a variety of mechanisms, including positioning of nucleosomes over promoters of some target genes to limit accessibility to the transcription machinery. To further define the functions of Cyc8–Tup1 in gene regulation and chromatin remodeling, we performed genome-wide profiling of changes in nucleosome organization and gene expression that occur upon loss of CYC8 or TUP1 and observed extensive nucleosome alterations in both promoters and gene bodies of derepressed genes. Our improved nucleosome profiling and analysis approaches revealed low-occupancy promoter nucleosomes (P nucleosomes) at locations previously defined as nucleosome-free regions. In the absence of CYC8 or TUP1, this P nucleosome is frequently lost, whereas nucleosomes are gained at −1 and +1 positions, accompanying up-regulation of downstream genes. Our analysis of public ChIP-seq data revealed that Cyc8 and Tup1 preferentially bind TATA-containing promoters, which are also enriched in genes derepressed upon loss of CYC8 or TUP1. These results suggest that stabilization of the P nucleosome on TATA-containing promoters may be a central feature of the repressive chromatin architecture created by the Cyc8–Tup1 corepressor, and that releasing the P nucleosome contributes to gene activation.
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Affiliation(s)
- Kaifu Chen
- Division of Biostatistics, Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
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24
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Wong KH, Struhl K. The Cyc8-Tup1 complex inhibits transcription primarily by masking the activation domain of the recruiting protein. Genes Dev 2011; 25:2525-39. [PMID: 22156212 PMCID: PMC3243062 DOI: 10.1101/gad.179275.111] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 10/14/2011] [Indexed: 12/22/2022]
Abstract
The yeast Tup1-Cyc8 corepressor complex is recruited to promoters by DNA-binding repressors, but the mechanisms by which it inhibits expression of genes involved in various stress pathways are poorly understood. Conditional and rapid depletion of Tup1 from the nucleus leads to concurrent nucleosome depletion and histone acetylation, recruitment of coactivators (Swi/Snf, SAGA, and Mediator), and increased transcriptional activity. Conversely, coactivator dissociation occurs rapidly upon rerepression by Cyc8-Tup1, although coactivator association and transcription can be blocked even in the absence of nucleosomes. The coactivators are recruited to the sites where Tup1 was located prior to depletion, indicating that the repressor proteins that recruit Tup1 function as activators in its absence. Last, Cyc8-Tup1 can interact with activation domains in vivo. Thus, Cyc8-Tup1 regulates transcription primarily by masking and inhibiting the transcriptional activation domains of the recruiting proteins, not by acting as a corepressor. We suggest that the corepressor function of Cyc8-Tup1 makes only a modest contribution to expression of target genes, specifically to keep expression levels below the nonactivated state.
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Affiliation(s)
| | - Kevin Struhl
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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25
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The specificity and topology of chromatin interaction pathways in yeast. Mol Cell 2011; 42:536-49. [PMID: 21596317 DOI: 10.1016/j.molcel.2011.03.026] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 01/12/2011] [Accepted: 03/18/2011] [Indexed: 01/07/2023]
Abstract
Packaging of DNA into chromatin has a profound impact on gene expression. To understand how changes in chromatin influence transcription, we analyzed 165 mutants of chromatin machinery components in Saccharomyces cerevisiae. mRNA expression patterns change in 80% of mutants, always with specific effects, even for loss of widespread histone marks. The data are assembled into a network of chromatin interaction pathways. The network is function based, has a branched, interconnected topology, and lacks strict one-to-one relationships between complexes. Chromatin pathways are not separate entities for different gene sets, but share many components. The study evaluates which interactions are important for which genes and predicts additional interactions, for example between Paf1C and Set3C, as well as a role for Mediator in subtelomeric silencing. The results indicate the presence of gene-dependent effects that go beyond context-dependent binding of chromatin factors and provide a framework for understanding how specificity is achieved through regulating chromatin.
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26
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Rizzo JM, Mieczkowski PA, Buck MJ. Tup1 stabilizes promoter nucleosome positioning and occupancy at transcriptionally plastic genes. Nucleic Acids Res 2011; 39:8803-19. [PMID: 21785133 PMCID: PMC3203618 DOI: 10.1093/nar/gkr557] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Despite technical advances, the future of chromatin mapping studies requires an ability to draw accurate comparisons between different chromatin states to enhance our understanding of genome biology. In this study, we used matched chromatin preparations to enable specific and accurate comparisons of Saccharomyces cerevisiae chromatin structures in the presence and absence of the co-repressor protein Tup1. Analysis of wild-type and tup1 Δ chromatin data sets revealed unique organizational themes relating to the function of Tup1. Regulatory regions bound by Tup1 assumed a distinct chromatin architecture composed of a wide nucleosome-depleted region, low occupancy/poorly positioned promoter nucleosomes, a larger number and wider distribution of transcription factor-binding sites and downstream genes with enhanced transcription plasticity. Regions of Tup1-dependent chromatin structure were defined for the first time across the entire yeast genome and are shown to strongly overlap with activity of the chromatin remodeler Isw2. Additionally, Tup1-dependent chromatin structures are shown to relate to distinct biological processes and transcriptional states of regulated genes, including Tup1 stabilization of Minus 1 and Minus 2 promoter nucleosomes at actively repressed genes. Together these results help to enhance our mechanistic understanding of Tup1 regulation of chromatin structure and gene expression.
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Affiliation(s)
- Jason M Rizzo
- Department of Biochemistry and Center of Excellence in Bioinformatics and Life Sciences, State University of New York at Buffalo, NY 14203, USA
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27
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Zhu X, Zhang Y, Bjornsdottir G, Liu Z, Quan A, Costanzo M, Dávila López M, Westholm JO, Ronne H, Boone C, Gustafsson CM, Myers LC. Histone modifications influence mediator interactions with chromatin. Nucleic Acids Res 2011; 39:8342-54. [PMID: 21742760 PMCID: PMC3201872 DOI: 10.1093/nar/gkr551] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The Mediator complex transmits activation signals from DNA bound transcription factors to the core transcription machinery. Genome wide localization studies have demonstrated that Mediator occupancy not only correlates with high levels of transcription, but that the complex also is present at transcriptionally silenced locations. We provide evidence that Mediator localization is guided by an interaction with histone tails, and that this interaction is regulated by their post-translational modifications. A quantitative, high-density genetic interaction map revealed links between Mediator components and factors affecting chromatin structure, especially histone deacetylases. Peptide binding assays demonstrated that pure wild-type Mediator forms stable complexes with the tails of Histone H3 and H4. These binding assays also showed Mediator-histone H4 peptide interactions are specifically inhibited by acetylation of the histone H4 lysine 16, a residue critical in transcriptional silencing. Finally, these findings were validated by tiling array analysis that revealed a broad correlation between Mediator and nucleosome occupancy in vivo, but a negative correlation between Mediator and nucleosomes acetylated at histone H4 lysine 16. Our studies show that chromatin structure and the acetylation state of histones are intimately connected to Mediator localization.
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Affiliation(s)
- Xuefeng Zhu
- Department of Biochemistry and Cell Biology, University of Gothenburg, SE-405 30 Gothenburg, Sweden
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Islam A, Turner EL, Menzel J, Malo ME, Harkness TA. Antagonistic Gcn5-Hda1 interactions revealed by mutations to the Anaphase Promoting Complex in yeast. Cell Div 2011; 6:13. [PMID: 21651791 PMCID: PMC3141613 DOI: 10.1186/1747-1028-6-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 06/08/2011] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Histone post-translational modifications are critical for gene expression and cell viability. A broad spectrum of histone lysine residues have been identified in yeast that are targeted by a variety of modifying enzymes. However, the regulation and interaction of these enzymes remains relatively uncharacterized. Previously we demonstrated that deletion of either the histone acetyltransferase (HAT) GCN5 or the histone deacetylase (HDAC) HDA1 exacerbated the temperature sensitive (ts) mutant phenotype of the Anaphase Promoting Complex (APC) apc5CA allele. Here, the apc5CA mutant background is used to study a previously uncharacterized functional antagonistic genetic interaction between Gcn5 and Hda1 that is not detected in APC5 cells. RESULTS Using Northerns, Westerns, reverse transcriptase PCR (rtPCR), chromatin immunoprecipitation (ChIP), and mutant phenotype suppression analysis, we observed that Hda1 and Gcn5 appear to compete for recruitment to promoters. We observed that the presence of Hda1 can partially occlude the binding of Gcn5 to the same promoter. Occlusion of Gcn5 recruitment to these promoters involved Hda1 and Tup1. Using sequential ChIP we show that Hda1 and Tup1 likely form complexes at these promoters, and that complex formation can be increased by deleting GCN5. CONCLUSIONS Our data suggests large Gcn5 and Hda1 containing complexes may compete for space on promoters that utilize the Ssn6/Tup1 repressor complex. We predict that in apc5CA cells the accumulation of an APC target may compensate for the loss of both GCN5 and HDA1.
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Affiliation(s)
- Azharul Islam
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada.
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29
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Brückner S, Mösch HU. Choosing the right lifestyle: adhesion and development in Saccharomyces cerevisiae. FEMS Microbiol Rev 2011; 36:25-58. [PMID: 21521246 DOI: 10.1111/j.1574-6976.2011.00275.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The budding yeast Saccharomyces cerevisiae is a eukaryotic microorganism that is able to choose between different unicellular and multicellular lifestyles. The potential of individual yeast cells to switch between different growth modes is advantageous for optimal dissemination, protection and substrate colonization at the population level. A crucial step in lifestyle adaptation is the control of self- and foreign adhesion. For this purpose, S. cerevisiae contains a set of cell wall-associated proteins, which confer adhesion to diverse biotic and abiotic surfaces. Here, we provide an overview of different aspects of S. cerevisiae adhesion, including a detailed description of known lifestyles, recent insights into adhesin structure and function and an outline of the complex regulatory network for adhesin gene regulation. Our review shows that S. cerevisiae is a model system suitable for studying not only the mechanisms and regulation of cell adhesion, but also the role of this process in microbial development, ecology and evolution.
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Affiliation(s)
- Stefan Brückner
- Department of Genetics, Philipps-Universität Marburg, Marburg, Germany
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30
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Minard LV, Williams JS, Walker AC, Schultz MC. Transcriptional regulation by Asf1: new mechanistic insights from studies of the DNA damage response to replication stress. J Biol Chem 2010; 286:7082-92. [PMID: 21190944 PMCID: PMC3044965 DOI: 10.1074/jbc.m110.193813] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Asf1 is a conserved histone H3/H4 chaperone. We find that Asf1 in budding yeast promotes an essential cellular response to replication stress caused by the ribonucleotide reductase inhibitor hydroxyurea. That is, Asf1 stimulates derepression of DNA damage response (DDR) genes during the S phase. Derepression of DDR genes strongly correlates with Asf1 binding to their promoters. Having identified the C terminus and histone-binding domains of Asf1 as molecular determinants of its constitutive and inducible association with chromatin, we tested whether Asf1 binding to DDR genes is mechanistically important for their derepression. Our results provide little support for this hypothesis. Rather, the contribution of Asf1 to DDR gene derepression depends on its ability to stimulate H3K56 acetylation by lysine acetyltransferase Rtt109. The precise regulation of H3K56 acetylation in the promoters of DDR genes is unexpected: DDR gene promoters are occupied by H3K56-acetylated nucleosomes under repressing conditions, and the steady state level of H3K56 promoter acetylation does not change upon derepression. We propose that replication-coupled deposition of Lys56-acetylated H3 poises the DDR genes in newly synthesized daughter duplexes for derepression during the S phase. In this model, the presence of a histone mark that destabilizes nucleosomes is compatible with suppression of transcription because in the uninduced state, DDR gene promoters are constitutively occupied by a potent repressor-corepressor complex.
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Affiliation(s)
- Laura V Minard
- Department of Biochemistry, School of Molecular and Systems Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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31
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A role in the regulation of transcription by light for RCO-1 and RCM-1, the Neurospora homologs of the yeast Tup1-Ssn6 repressor. Fungal Genet Biol 2010; 47:939-52. [PMID: 20709620 DOI: 10.1016/j.fgb.2010.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 07/29/2010] [Accepted: 08/02/2010] [Indexed: 12/15/2022]
Abstract
The activation of gene transcription by light is transient since light-dependent mRNA accumulation ceases after long exposures to light. This phenomenon, photoadaptation, has been observed in plants and fungi, and allows the perception of changes in light intensities. In the fungus Neurosporacrassa photoadaptation involves the transient binding of the photoresponsive White Collar Complex (WCC) to the promoters of light-regulated genes. We show that RCO-1 and RCM-1, the Neurospora homologs of the components of the yeast Tup1-Ssn6 repressor complex, participate in photoadaptation. Mutation in either rco-1 or rcm-1 result in high and sustained accumulation of mRNAs for con-10 and other light-regulated genes after long exposures to light. The mutation of rco-1 increased the sensitivity to light for con-10 activation and delayed synthesis and/or degradation of con-10 and con-6 mRNAs without altering the amount or the light-dependent phosphorylation of the photoreceptor WC-1. RCO-1 and RCM-1 are located in the Neurospora nuclei were they regulate gene transcription. We show that RCO-1 and RCM-1 participate in the light-transduction pathway of Neurospora and has a role in photoadaptation by repressing gene transcription after long exposures to light.
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32
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Ferreira ME, Berndt KD, Nilsson J, Wright APH. WD40 domain divergence is important for functional differences between the fission yeast Tup11 and Tup12 co-repressor proteins. PLoS One 2010; 5:e11009. [PMID: 20544037 PMCID: PMC2882346 DOI: 10.1371/journal.pone.0011009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 04/28/2010] [Indexed: 11/19/2022] Open
Abstract
We have previously demonstrated that subsets of Ssn6/Tup target genes have distinct requirements for the Schizosaccharomyces pombe homologs of the Tup1/Groucho/TLE co-repressor proteins, Tup11 and Tup12. The very high level of divergence in the histone interacting repression domains of the two proteins suggested that determinants distinguishing Tup11 and Tup12 might be located in this domain. Here we have combined phylogenetic and structural analysis as well as phenotypic characterization, under stress conditions that specifically require Tup12, to identify and characterize the domains involved in Tup12-specific action. The results indicate that divergence in the repression domain is not generally relevant for Tup12-specific function. Instead, we show that the more highly conserved C-terminal WD40 repeat domain of Tup12 is important for Tup12-specific function. Surface amino acid residues specific for the WD40 repeat domain of Tup12 proteins in different fission yeasts are clustered in blade 3 of the propeller-like structure that is characteristic of WD40 repeat domains. The Tup11 and Tup12 proteins in fission yeasts thus provide an excellent model system for studying the functional divergence of WD40 repeat domains.
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Affiliation(s)
- Monica E. Ferreira
- School of Life Sciences, Södertörn University, Huddinge, Sweden
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Kurt D. Berndt
- School of Life Sciences, Södertörn University, Huddinge, Sweden
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Johan Nilsson
- School of Life Sciences, Södertörn University, Huddinge, Sweden
| | - Anthony P. H. Wright
- School of Life Sciences, Södertörn University, Huddinge, Sweden
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
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Corepressor-directed preacetylation of histone H3 in promoter chromatin primes rapid transcriptional switching of cell-type-specific genes in yeast. Mol Cell Biol 2010; 30:3342-56. [PMID: 20439496 DOI: 10.1128/mcb.01450-09] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Switching between alternate states of gene transcription is fundamental to a multitude of cellular regulatory pathways, including those that govern differentiation. In spite of the progress in our understanding of such transitions in gene activity, a major unanswered question is how cells regulate the timing of these switches. Here, we have examined the kinetics of a transcriptional switch that accompanies the differentiation of yeast cells of one mating type into a distinct new cell type. We found that cell-type-specific genes silenced by the alpha2 repressor in the starting state are derepressed to establish the new mating-type-specific gene expression program coincident with the loss of alpha2 from promoters. This rapid derepression does not require the preloading of RNA polymerase II or a preinitiation complex but instead depends upon the Gcn5 histone acetyltransferase. Surprisingly, Gcn5-dependent acetylation of nucleosomes in the promoters of mating-type-specific genes requires the corepressor Ssn6-Tup1 even in the repressed state. Gcn5 partially acetylates the amino-terminal tails of histone H3 in repressed promoters, thereby priming them for rapid derepression upon loss of alpha2. Thus, Ssn6-Tup1 not only efficiently represses these target promoters but also functions to initiate derepression by creating a chromatin state poised for rapid activation.
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Zhu J, Zhao Y, Wang S. Chromatin and epigenetic regulation of the telomerase reverse transcriptase gene. Protein Cell 2010; 1:22-32. [PMID: 21203995 DOI: 10.1007/s13238-010-0014-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Accepted: 12/03/2009] [Indexed: 01/30/2023] Open
Abstract
Telomerase expression and telomere maintenance are critical for long-term cell proliferation and survival, and they play important roles in development, aging, and cancer. Cumulating evidence has indicated that regulation of the rate-limiting subunit of human telomerase reverse transcriptase gene (hTERT) is a complex process in normal cells and many cancer cells. In addition to a number of transcriptional activators and repressors, the chromatin environment and epigenetic status of the endogenous hTERT locus are also pivotal for its regulation in normal human somatic cells and in tumorigenesis.
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Affiliation(s)
- Jiyue Zhu
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
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35
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Wang S, Hu C, Zhu J. Distinct and temporal roles of nucleosomal remodeling and histone deacetylation in the repression of the hTERT gene. Mol Biol Cell 2010; 21:821-32. [PMID: 20053684 PMCID: PMC2828968 DOI: 10.1091/mbc.e09-06-0456] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Transcriptional silencing of the hTERT gene during HL60 cell differentiation was a biphasic process. The initial repression was accompanied by the loss of c-Myc binding and disappearance of a nucleosome-free region at the core promoter. The subsequent nucleosomal remodeling and histone modifications at the promoter stabilized this repression. hTERT, the human telomerase reverse transcriptase, is highly expressed in stem cells and embryonic tissues but undetectable in most adult somatic cells. To understand its repression mechanisms in somatic cells, we investigated the endogenous hTERT gene regulation during differentiation of human leukemic HL60 cells. Our study revealed that silencing of the hTERT promoter was a biphasic process. Within 24 h after initiation of differentiation, hTERT mRNA expression decreased dramatically, accompanied by increased expression of Mad1 gene and disappearance of a nucleosome-free region at the hTERT core promoter. Subsequent to this early repression, nucleosomal remodeling continued at the promoter and downstream region for several days, as demonstrated by micrococcal nuclease and restriction enzyme accessibility assays. This later nucleosomal remodeling correlated with stable silencing of the hTERT promoter. Progressive changes of core histone modifications occurred throughout the entire differentiation process. Surprisingly, inhibition of histone deacetylation at the hTERT promoter did not prevent hTERT repression or nucleosomal deposition, indicating that nucleosomal deposition at the core promoter, but not histone deacetylation, was the cause of transcriptional repression. Our data also suggested that succeeding nucleosomal remodeling and histone deacetylation worked in parallel to establish the stable repressive status of hTERT gene in human somatic cells.
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Affiliation(s)
- Shuwen Wang
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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36
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A novel mechanism of antagonism between ATP-dependent chromatin remodeling complexes regulates RNR3 expression. Mol Cell Biol 2009; 29:3255-65. [PMID: 19349301 DOI: 10.1128/mcb.01741-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Gene expression depends upon the antagonistic actions of chromatin remodeling complexes. While this has been studied extensively for the enzymes that covalently modify the tails of histones, the mechanism of how ATP-dependent remodeling complexes antagonize each other to maintain the proper level of gene activity is not known. The gene encoding a large subunit of ribonucleotide reductase, RNR3, is regulated by ISW2 and SWI/SNF, complexes that repress and activate transcription, respectively. Here, we studied the functional interactions of these two complexes at RNR3. Deletion of ISW2 causes constitutive recruitment of SWI/SNF, and conditional reexpression of ISW2 causes the repositioning of nucleosomes and reduced SWI/SNF occupancy at RNR3. Thus, ISW2 is required for restriction of access of SWI/SNF to the RNR3 promoter under the uninduced condition. Interestingly, the binding of sequence-specific DNA binding factors and the general transcription machinery are unaffected by the status of ISW2, suggesting that disruption of nucleosome positioning does not cause a nonspecific increase in cross-linking of all factors to RNR3. We provide evidence that ISW2 does not act on SWI/SNF directly but excludes its occupancy by positioning nucleosomes over the promoter. Genetic disruption of nucleosome positioning by other means led to a similar phenotype, linking repressed chromatin structure to SWI/SNF exclusion. Thus, incorporation of promoters into a repressive chromatin structure is essential for prevention of the opportunistic actions of nucleosome-disrupting activities in vivo, providing a novel mechanism for maintaining tight control of gene expression.
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37
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Ratna P, Scherrer S, Fleischli C, Becskei A. Synergy of repression and silencing gradients along the chromosome. J Mol Biol 2009; 387:826-39. [PMID: 19233208 DOI: 10.1016/j.jmb.2009.02.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 02/10/2009] [Accepted: 02/12/2009] [Indexed: 01/28/2023]
Abstract
The expression of a gene is determined by the transcriptional activators and repressors bound to its regulatory regions. It is not clear how these opposing activities are summed to define the degree of silencing of genes within a segment of the eukaryotic chromosome. We show that the general repressor Ssn6 and the silencing protein Sir3 generate inhibitory gradients with similar slopes over a transcribed gene, even though Ssn6 is considered a promoter-specific repressor of single genes, while Sir3 is a regional silencer. When two repression or silencing gradients flank a gene, they have a multiplicative effect on gene expression. A significant amplification of the interacting gradients distinguishes silencing from repression. When a silencing gradient is enhanced, the distance-dependence of the amplification changes and long-range effects are established preferentially. These observations reveal that repression and silencing proteins can attain different tiers in a hierarchy of conserved regulatory modes. The quantitative rules associated with these modes will help to explain the co-expression pattern of adjacent genes in the genome.
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Affiliation(s)
- Prasuna Ratna
- Institute of Molecular Biology, University of Zurich, Zurich, Switzerland
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38
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GarcÃa I, Mathieu M, Nikolaev I, Felenbok BÃ, Scazzocchio C. Roles of theAspergillus nidulanshomologues of Tup1 and Ssn6 in chromatin structure and cell viability. FEMS Microbiol Lett 2008; 289:146-54. [DOI: 10.1111/j.1574-6968.2008.01379.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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39
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Zhang H, Kruk JA, Reese JC. Dissection of coactivator requirement at RNR3 reveals unexpected contributions from TFIID and SAGA. J Biol Chem 2008; 283:27360-27368. [PMID: 18682387 DOI: 10.1074/jbc.m803831200] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The gene encoding ribonucleotide reductase 3 (RNR3) is strongly induced in response to DNA damage. Its expression is strictly dependent upon the TAF(II) subunits of TFIID, which are required for the recruitment of SWI/SNF and nucleosome remodeling. However, full activation of RNR3 also requires GCN5, the catalytic subunit of the SAGA histone acetyltransferase complex. Thus, RNR3 is dependent upon both TFIID and SAGA, two complexes that deliver TATA-binding protein (TBP) to promoters. Furthermore, unlike the majority of TFIID-dominated genes, RNR3 contains a consensus TATA-box, a feature of SAGA-regulated core promoters. Although a large fraction of the genome can be characterized as either TFIID- or SAGA-dominant, it is expected that many genes utilize both. The mechanism of activation and the relative contributions of SAGA and TFIID at genes regulated by both complexes have not been examined. Here we delineated the role of SAGA in the regulation of RNR3 and contrast it to that of TFIID. We find that SAGA components fulfill distinct functions in the regulation of RNR3. The core promoter of RNR3 is SAGA-dependent, and we provide evidence that SAGA, not TAF(II)s within TFIID, are largely responsible for TBP recruitment. This taken together with our previous work provides evidence that SAGA recruits TBP, whereas TFIID mediates chromatin remodeling. Thus, we described an unexpected shift in the division of labor between these two complexes and provide the first characterization of a gene that requires both SAGA and TFIID.
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Affiliation(s)
- Hesheng Zhang
- Department of Biochemistry and Molecular Biology, Center for Gene Regulation, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Jennifer A Kruk
- Department of Biochemistry and Molecular Biology, Center for Gene Regulation, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Joseph C Reese
- Department of Biochemistry and Molecular Biology, Center for Gene Regulation, Pennsylvania State University, University Park, Pennsylvania 16802.
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40
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Yeast Rap1 contributes to genomic integrity by activating DNA damage repair genes. EMBO J 2008; 27:1575-84. [PMID: 18480842 DOI: 10.1038/emboj.2008.93] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 04/14/2008] [Indexed: 11/08/2022] Open
Abstract
Rap1 (repressor-activator protein 1) is a multifunctional protein that controls telomere function, silencing and the activation of glycolytic and ribosomal protein genes. We have identified a novel function for Rap1, regulating the ribonucleotide reductase (RNR) genes that are required for DNA repair and telomere expansion. Both the C terminus and DNA-binding domain of Rap1 are required for the activation of the RNR genes, and the phenotypes of different Rap1 mutants suggest that it utilizes both regions to carry out distinct steps in the activation process. Recruitment of Rap1 to the RNR3 gene is dependent on activation of the DNA damage checkpoint and chromatin remodelling by SWI/SNF. The dependence on SWI/SNF for binding suggests that Rap1 acts after remodelling to prevent the repositioning of nucleosomes back to the repressed state. Furthermore, the recruitment of Rap1 requires TAF(II)s, suggesting a role for TFIID in stabilizing activator binding in vivo. We propose that Rap1 acts as a rheostat controlling nucleotide pools in response to shortened telomeres and DNA damage, providing a mechanism for fine-tuning the RNR genes during checkpoint activation.
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41
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Rippe K, Schrader A, Riede P, Strohner R, Lehmann E, Längst G. DNA sequence- and conformation-directed positioning of nucleosomes by chromatin-remodeling complexes. Proc Natl Acad Sci U S A 2007; 104:15635-40. [PMID: 17893337 PMCID: PMC2000439 DOI: 10.1073/pnas.0702430104] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Chromatin-remodeling complexes can translocate nucleosomes along the DNA in an ATP-coupled reaction. This process is an important regulator of all DNA-dependent processes because it determines whether certain DNA sequences are found in regions between nucleosomes with increased accessibility for other factors or wrapped around the histone octamer complex. In a comparison of seven different chromatin-remodeling machines (ACF, ISWI, Snf2H, Chd1, Mi-2, Brg1, and NURF), it is demonstrated that these complexes can read out DNA sequence features to establish specific nucleosome-positioning patterns. For one of the remodelers, ACF, we identified a 40-bp DNA sequence element that directs nucleosome positioning. Furthermore, we show that nucleosome positioning by the remodelers ACF and Chd1 is determined by a reduced affinity to the end product of the translocation reaction. The results suggest that the linkage of differential remodeling activities with the intrinsic binding preferences of nucleosomes can result in establishing distinct chromatin structures that depend on the DNA sequence and define the DNA accessibility for other protein factors.
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Affiliation(s)
- Karsten Rippe
- *Division of Genome Organization and Function, Deutsches Krebsforschungszentrum and Bioquant, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Anna Schrader
- Biochemie III, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Philipp Riede
- Biochemie III, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Ralf Strohner
- Biochemie III, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Elisabeth Lehmann
- Gene Center Munich, Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; and
| | - Gernot Längst
- Biochemie III, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
- To whom correspondence should be addressed. E-mail:
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Mulder KW, Inagaki A, Cameroni E, Mousson F, Winkler GS, De Virgilio C, Collart MA, Timmers HTM. Modulation of Ubc4p/Ubc5p-mediated stress responses by the RING-finger-dependent ubiquitin-protein ligase Not4p in Saccharomyces cerevisiae. Genetics 2007; 176:181-92. [PMID: 17513889 PMCID: PMC1893070 DOI: 10.1534/genetics.106.060640] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Ccr4-Not complex consists of nine subunits and acts as a regulator of mRNA biogenesis in Saccharomyces cerevisiae. The human ortholog of yeast NOT4, CNOT4, displays UbcH5B-dependent ubiquitin-protein ligase (E3 ligase) activity in a reconstituted in vitro system. However, an in vivo role for this enzymatic activity has not been identified. Site-directed mutagenesis of the RING finger of yeast Not4p identified residues required for interaction with Ubc4p and Ubc5p, the yeast orthologs of UbcH5B. Subsequent in vitro assays with purified Ccr4-Not complexes showed Not4p-mediated E3 ligase activity, which was dependent on the interaction with Ubc4p. To investigate the in vivo relevance of this activity, we performed synthetic genetic array (SGA) analyses using not4Delta and not4L35A alleles. This indicates involvement of the RING finger of Not4p in transcription, ubiquitylation, and DNA damage responses. In addition, we found a phenotypic overlap between deletions of UBC4 and mutants encoding single-amino-acid substitutions of the RING finger of Not4p. Together, our results show that Not4p functions as an E3 ligase by modulating Ubc4p/Ubc5p-mediated stress responses in vivo.
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Affiliation(s)
- Klaas W Mulder
- Department of Physiological Chemistry, University Medical Centre Utrecht, Utrecht, The Netherlands
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Núñez L, González-Siso MI, Becerra M, Cerdán ME. Functional motifs outside the kinase domain of yeast Srb10p. Their role in transcriptional regulation and protein-interactions with Tup1p and Srb11p. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:1227-35. [PMID: 17689156 DOI: 10.1016/j.bbapap.2007.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 06/21/2007] [Accepted: 06/26/2007] [Indexed: 11/16/2022]
Abstract
Several derivatives of the native Srb10 proteins from Saccharomyces cerevisiae and Kluyveromyces lactis, with removed selected motifs, have been constructed in order to test their role in Srb10p function. It has been demonstrated that the ATP binding site is necessary for repression of FLO11, CYC7 and SPI1. Yeast Srb10p specific motifs CM-I and CM-II, outside the kinase domain, are also necessary to complement two mutant phenotypes in S. cerevisiae Deltasrb10 strains, the failure to growth in galactose at 37 degrees C and flocculation. They are also required to keep transcriptional repression of FLO11 in non-flocculants, and for aerobic repression of CYC7 and SPI1. Two-hybrid analyses revealed that, in Srb10p derivatives, the absence of these motifs decreases the interaction of Srb10p with its cyclin partner Srb11p and with the component Tup1p of the general co-repressor complex Tup1p-Ssn6p.
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Affiliation(s)
- Laura Núñez
- Departamento de Biología Celular y Molecular. Facultad de Ciencias, Universidad de A Coruña, 15071, Spain
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Fleming AB, Pennings S. Tup1-Ssn6 and Swi-Snf remodelling activities influence long-range chromatin organization upstream of the yeast SUC2 gene. Nucleic Acids Res 2007; 35:5520-31. [PMID: 17704134 PMCID: PMC2018639 DOI: 10.1093/nar/gkm573] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The traditional model for chromatin remodelling during transcription has focused upon the remodelling of nucleosomes at gene promoters. However, in this study, we have determined that Tup1-Ssn6 and Swi-Snf chromatin remodelling activities extend far upstream of the SUC2 gene promoter into the intergenic region of the Saccharomyces cerevisiae chromosome. We mapped the nucleosomal array over a 7.5 kb region that encompassed the SUC2 gene promoter and upstream region but was devoid of other transcriptionally active genes. Nucleosome positioning over this region was determined under conditions of glucose repression and derepression, and in snf2, ssn6 and snf2 ssn6 mutant strains. A map detailing remodelling events extending as much as 5 kb upstream of the SUC2 gene promoter underlines the roles of the Tup1-Ssn6 and Swi-Snf complexes in respectively organizing and disrupting nucleosome arrays. The gene specificity of these events suggests a role in gene regulation. We propose that long-range chromatin remodelling activities of Swi-Snf and Tup1-Ssn6 may ultimately influence whether the chromosomal state of the SUC2 gene is proficient for transcription. These data raise the possibility that remodelling of extensive chromatin domains may be a general property of the Swi-Snf and Tup1-Ssn6 complexes.
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Affiliation(s)
- Alastair B. Fleming
- Department of Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK, Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, Albuquerque, New Mexico 87131, USA and Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Sari Pennings
- Department of Biomedical Sciences, University of Edinburgh, Edinburgh, EH8 9XD, UK, Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, Albuquerque, New Mexico 87131, USA and Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
- *To whom correspondence should be addressed. +44 131 242 6145+44 131 242 6782
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Chen RE, Thorner J. Function and regulation in MAPK signaling pathways: lessons learned from the yeast Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1773:1311-40. [PMID: 17604854 PMCID: PMC2031910 DOI: 10.1016/j.bbamcr.2007.05.003] [Citation(s) in RCA: 442] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 05/02/2007] [Accepted: 05/04/2007] [Indexed: 10/23/2022]
Abstract
Signaling pathways that activate different mitogen-activated protein kinases (MAPKs) elicit many of the responses that are evoked in cells by changes in certain environmental conditions and upon exposure to a variety of hormonal and other stimuli. These pathways were first elucidated in the unicellular eukaryote Saccharomyces cerevisiae (budding yeast). Studies of MAPK pathways in this organism continue to be especially informative in revealing the molecular mechanisms by which MAPK cascades operate, propagate signals, modulate cellular processes, and are controlled by regulatory factors both internal to and external to the pathways. Here we highlight recent advances and new insights about MAPK-based signaling that have been made through studies in yeast, which provide lessons directly applicable to, and that enhance our understanding of, MAPK-mediated signaling in mammalian cells.
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Affiliation(s)
- Raymond E Chen
- Division of Biochemistry and Molecular Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA
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Zhang H, Reese JC. Exposing the core promoter is sufficient to activate transcription and alter coactivator requirement at RNR3. Proc Natl Acad Sci U S A 2007; 104:8833-8. [PMID: 17502614 PMCID: PMC1885588 DOI: 10.1073/pnas.0701666104] [Citation(s) in RCA: 28] [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
Chromatin is a formidable barrier to transcription. Nucleosome density is lowest over the regulatory regions of active genes, and many repressed genes have a tightly positioned nucleosome over their core promoter. However, it has not been shown that nucleosome positioning is sufficient for repression or whether disrupting a core promoter nucleosome specifically can activate gene expression in the absence of activating signals. Here we show that disrupting the nucleosome over the core promoter of RNR3 is sufficient to drive preinitiation complex assembly and activate transcription in the absence of activating signals. Remodeling of chromatin over the RNR3 promoter requires the recruitment of the SWI/SNF complex by the general transcription factor TFIID. We found that disrupting the nucleosome over the RNR3 core promoter relieves its dependence on TFIID and SWI/SNF, indicating a functional link between these two complexes. These results suggest that the specific function of TAF(II)s is to direct the chromatin remodeling step through SWI/SNF recruitment, and not core promoter selectivity. Our results indicate that nucleosome placement plays a dominant role in repression and that the ability of the core promoter to position a nucleosome is a major determinant in TAF(II) dependency of genes in vivo.
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Affiliation(s)
- Hesheng Zhang
- Department of Biochemistry and Molecular Biology, Center for Gene Regulation, Pennsylvania State University, University Park, PA 16802
| | - Joseph C. Reese
- Department of Biochemistry and Molecular Biology, Center for Gene Regulation, Pennsylvania State University, University Park, PA 16802
- *To whom correspondence should be addressed. E-mail:
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Gligoris T, Thireos G, Tzamarias D. The Tup1 corepressor directs Htz1 deposition at a specific promoter nucleosome marking the GAL1 gene for rapid activation. Mol Cell Biol 2007; 27:4198-205. [PMID: 17387147 PMCID: PMC1900012 DOI: 10.1128/mcb.00238-07] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The SWR1 complex (SWR1-C)-dependent deposition of the histone variant Htz1 on promoter nucleosomes is typical of Saccharomyces cerevisiae genes whose expression is frequently reprogrammed. Although this epigenetic marking is of significant physiological importance, the determinants of Htz1 deposition, the conditions that set off SWR1-C occupancy, and the implications of Htz1 in transcriptional initiation are issues that remain unresolved. In this report, we addressed these questions by investigating the GAL1 promoter. We show that Htz1 is required for efficient Mediator recruitment and transcription only when the GAL1 promoter is under the influence of the Tup1 corepressor. In fact, we show that it is Tup1 that specifies Htz1 deposition for the promoter nucleosome covering the transcription start site. This deposition occurs rapidly following transcriptional repression, and it correlates with a Tup1-independent transient recruitment of the SWR1 complex. We propose that Tup1 cooperates with SWR1-C and specifies Htz1 deposition at GAL1, thereby marking the promoter for rapid neutralization from its repressive effects.
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Affiliation(s)
- Thomas Gligoris
- Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology, University of Crete, P.O. Box 1527, Vassilika Vouton, 711 10 Heraklion, Crete, Greece.
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Sharma VM, Tomar RS, Dempsey AE, Reese JC. Histone deacetylases RPD3 and HOS2 regulate the transcriptional activation of DNA damage-inducible genes. Mol Cell Biol 2007; 27:3199-210. [PMID: 17296735 PMCID: PMC1899941 DOI: 10.1128/mcb.02311-06] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DNA microarray and genetic studies of Saccharomyces cerevisiae have demonstrated that histone deacetylases (HDACs) are required for transcriptional activation and repression, but the mechanism by which they activate transcription remains poorly understood. We show that two HDACs, RPD3 and HOS2, are required for the activation of DNA damage-inducible genes RNR3 and HUG1. Using mutants specific for the Rpd3L complex, we show that the complex is responsible for regulating RNR3. Furthermore, unlike what was described for the GAL genes, Rpd3L regulates the activation of RNR3 by deacetylating nucleosomes at the promoter, not at the open reading frame. Rpd3 is recruited to the upstream repression sequence of RNR3, which surprisingly does not require Tup1 or Crt1. Chromatin remodeling and TFIID recruitment are largely unaffected in the Deltarpd3/Deltahos2 mutant, but the recruitment of RNA polymerase II is strongly reduced, arguing that Rpd3 and Hos2 regulate later stages in the assembly of the preinitiation complex or facilitate multiple rounds of polymerase recruitment. Furthermore, the histone H4 acetyltransferase Esa1 is required for the activation of RNR3 and HUG1. Thus, reduced or unregulated constitutive histone H4 acetylation is detrimental to promoter activity, suggesting that HDAC-dependent mechanisms are in place to reset promoters to allow high levels of transcription.
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Affiliation(s)
- Vishva Mitra Sharma
- Penn State University, Department of Biochemistry and Molecular Biology, 203 Althouse Lab, University Park, PA 16802, USA
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Argimón S, Wishart JA, Leng R, Macaskill S, Mavor A, Alexandris T, Nicholls S, Knight AW, Enjalbert B, Walmsley R, Odds FC, Gow NAR, Brown AJP. Developmental regulation of an adhesin gene during cellular morphogenesis in the fungal pathogen Candida albicans. EUKARYOTIC CELL 2007; 6:682-92. [PMID: 17277173 PMCID: PMC1865654 DOI: 10.1128/ec.00340-06] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Candida albicans expresses specific virulence traits that promote disease establishment and progression. These traits include morphological transitions between yeast and hyphal growth forms that are thought to contribute to dissemination and invasion and cell surface adhesins that promote attachment to the host. Here, we describe the regulation of the adhesin gene ALS3, which is expressed specifically during hyphal development in C. albicans. Using a combination of reporter constructs and regulatory mutants, we show that this regulation is mediated by multiple factors at the transcriptional level. The analysis of ALS3 promoter deletions revealed that this promoter contains two activation regions: one is essential for activation during hyphal development, while the second increases the amplitude of this activation. Further deletion analyses using the Renilla reniformis luciferase reporter delineate the essential activation region between positions -471 and -321 of the promoter. Further 5' or 3' deletions block activation. ALS3 transcription is repressed mainly by Nrg1 and Tup1, but Rfg1 contributes to this repression. Efg1, Tec1, and Bcr1 are essential for the transcriptional activation of ALS3, with Tec1 mediating its effects indirectly through Bcr1 rather than through the putative Tec1 sites in the ALS3 promoter. ALS3 transcription is not affected by Cph2, but Cph1 contributes to full ALS3 activation. The data suggest that multiple morphogenetic signaling pathways operate through the promoter of this adhesin gene to mediate its developmental regulation in this major fungal pathogen.
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Affiliation(s)
- Silvia Argimón
- School of Medical Sciences, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
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Sertil O, Vemula A, Salmon SL, Morse RH, Lowry CV. Direct role for the Rpd3 complex in transcriptional induction of the anaerobic DAN/TIR genes in yeast. Mol Cell Biol 2007; 27:2037-47. [PMID: 17210643 PMCID: PMC1820486 DOI: 10.1128/mcb.02297-06] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Saccharomyces cerevisiae adapts to hypoxia by expressing a large group of "anaerobic" genes. Among these, the eight DAN/TIR genes are regulated by the repressors Rox1 and Mot3 and the activator Upc2/Mox4. In attempting to identify factors recruited by the DNA binding repressor Mot3 to enhance repression of the DAN/TIR genes, we found that the histone deacetylase and global repressor complex, Rpd3-Sin3-Sap30, was not required for repression. Strikingly, the complex was instead required for activation. In addition, the histone H3 and H4 amino termini, which are targets of Rpd3, were also required for DAN1 expression. Epistasis tests demonstrated that the Rpd3 complex is not required in the absence of the repressor Mot3. Furthermore, the Rpd3 complex was required for normal function and stable binding of the activator Upc2 at the DAN1 promoter. Moreover, the Swi/Snf chromatin remodeling complex was strongly required for activation of DAN1, and chromatin immunoprecipitation analysis showed an Rpd3-dependent reduction in DAN1 promoter-associated nucleosomes upon induction. Taken together, these data provide evidence that during anaerobiosis, the Rpd3 complex acts at the DAN1 promoter to antagonize the chromatin-mediated repression caused by Mot3 and Rox1 and that chromatin remodeling by Swi/Snf is necessary for normal expression.
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Affiliation(s)
- Odeniel Sertil
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA.
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