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Kamata K, Ayano T, Oki M. Spt3 and Spt8 Are Involved in the Formation of a Silencing Boundary by Interacting with TATA-Binding Protein. Biomolecules 2023; 13:biom13040619. [PMID: 37189367 DOI: 10.3390/biom13040619] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 03/31/2023] Open
Abstract
In Saccharomyces cerevisiae, a heterochromatin-like chromatin structure called the silencing region is present at the telomere as a complex of Sir2, Sir3, and Sir4. Although spreading of the silencing region is blocked by histone acetylase-mediated boundary formation, the details of the factors and mechanisms involved in the spread and formation of the boundary at each telomere are unknown. Here, we show that Spt3 and Spt8 block the spread of the silencing regions. Spt3 and Spt8 are members of the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex, which has histone acetyltransferase activity. We performed microarray analysis of the transcriptome of spt3Δ and spt8Δ strains and RT-qPCR analysis of the transcript levels of genes from the subtelomeric region in mutants in which the interaction of Spt3 with TATA-binding protein (TBP) is altered. The results not only indicated that both Spt3 and Spt8 are involved in TBP-mediated boundary formation on the right arm of chromosome III, but also that boundary formation in this region is DNA sequence independent. Although both Spt3 and Spt8 interact with TBP, Spt3 had a greater effect on genome-wide transcription. Mutant analysis showed that the interaction between Spt3 and TBP plays an important role in the boundary formation.
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2
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Catala M, Abou Elela S. Promoter-dependent nuclear RNA degradation ensures cell cycle-specific gene expression. Commun Biol 2019; 2:211. [PMID: 31240249 PMCID: PMC6572803 DOI: 10.1038/s42003-019-0441-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/29/2019] [Indexed: 11/09/2022] Open
Abstract
Cell cycle progression depends on phase-specific gene expression. Here we show that the nuclear RNA degradation machinery plays a lead role in promoting cell cycle-dependent gene expression by triggering promoter-dependent co-transcriptional RNA degradation. Single molecule quantification of RNA abundance in different phases of the cell cycle indicates that relative curtailment of gene expression in certain phases is attained even when transcription is not completely inhibited. When nuclear ribonucleases are deleted, transcription of the Saccharomyces cerevisiae G1-specific axial budding gene AXL2 is detected throughout the cell cycle and its phase-specific expression is lost. Promoter replacement abolished cell cycle-dependent RNA degradation and rendered the RNA insensitive to the deletion of nuclear ribonucleases. Together the data reveal a model of gene regulation whereby RNA abundance is controlled by promoter-dependent induction of RNA degradation.
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Affiliation(s)
- Mathieu Catala
- Département de microbiologie et d’infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC J1E 4K8 Canada
| | - Sherif Abou Elela
- Département de microbiologie et d’infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC J1E 4K8 Canada
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3
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Improvement of Lead Tolerance of Saccharomyces cerevisiae by Random Mutagenesis of Transcription Regulator SPT3. Appl Biochem Biotechnol 2017; 184:155-167. [PMID: 28656551 DOI: 10.1007/s12010-017-2531-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/04/2017] [Indexed: 10/19/2022]
Abstract
Bioremediation of heavy metal pollution with biomaterials such as bacteria and fungi usually suffer from limitations because of microbial sensitivity to high concentration of heavy metals. Herein, we adopted a novel random mutagenesis technique called RAISE to manipulate the transcription regulator SPT3 of Saccharomyces cerevisiae to improve cell lead tolerance. The best strain Mutant VI was selected from the random mutagenesis libraries on account of the growth performance, with higher specific growth rate than the control strain (0.068 vs. 0.040 h-1) at lead concentration as high as 1.8 g/L. Combined with the transcriptome analysis of S. cerevisiae, expressing the SPT3 protein was performed to make better sense of the global regulatory effects of SPT3. The data analysis revealed that 57 of S. cerevisiae genes were induced and 113 genes were suppressed, ranging from those for trehalose synthesis, carbon metabolism, and nucleotide synthesis to lead resistance. Especially, the accumulation of intracellular trehalose in S. cerevisiae under certain conditions of stress is considered important to lead resistance. The above results represented that SPT3 was acted as global transcription regulator in the exponential phase of strain and accordingly improved heavy metal tolerance in the heterologous host S. cerevisiae. The present study provides a route to complex phenotypes that are not readily accessible by traditional methods.
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True JD, Muldoon JJ, Carver MN, Poorey K, Shetty SJ, Bekiranov S, Auble DT. The Modifier of Transcription 1 (Mot1) ATPase and Spt16 Histone Chaperone Co-regulate Transcription through Preinitiation Complex Assembly and Nucleosome Organization. J Biol Chem 2016; 291:15307-19. [PMID: 27226635 DOI: 10.1074/jbc.m116.735134] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Indexed: 11/06/2022] Open
Abstract
Modifier of transcription 1 (Mot1) is a conserved and essential Swi2/Snf2 ATPase that can remove TATA-binding protein (TBP) from DNA using ATP hydrolysis and in so doing exerts global effects on transcription. Spt16 is also essential and functions globally in transcriptional regulation as a component of the facilitates chromatin transcription (FACT) histone chaperone complex. Here we demonstrate that Mot1 and Spt16 regulate a largely overlapping set of genes in Saccharomyces cerevisiae. As expected, Mot1 was found to control TBP levels at co-regulated promoters. In contrast, Spt16 did not affect TBP recruitment. On a global scale, Spt16 was required for Mot1 promoter localization, and Mot1 also affected Spt16 localization to genes. Interestingly, we found that Mot1 has an unanticipated role in establishing or maintaining the occupancy and positioning of nucleosomes at the 5' ends of genes. Spt16 has a broad role in regulating chromatin organization in gene bodies, including those nucleosomes affected by Mot1. These results suggest that the large scale overlap in Mot1 and Spt16 function arises from a combination of both their unique and shared functions in transcription complex assembly and chromatin structure regulation.
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Affiliation(s)
- Jason D True
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Joseph J Muldoon
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Melissa N Carver
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Kunal Poorey
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Savera J Shetty
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Stefan Bekiranov
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - David T Auble
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
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5
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Durand A, Bonnet J, Fournier M, Chavant V, Schultz P. Mapping the deubiquitination module within the SAGA complex. Structure 2015; 22:1553-9. [PMID: 25441028 DOI: 10.1016/j.str.2014.07.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 07/25/2014] [Accepted: 07/25/2014] [Indexed: 11/25/2022]
Abstract
The molecular organization of the yeast transcriptional coactivator Spt-Ada-Gcn5 acetyltransferase (SAGA) was analyzed by single-particle electron microscopy. Complete or partial deletion of the Sgf73 subunit disconnects the deubiquitination (DUB) module from SAGA and favors in our conditions the cleavage of the C-terminal ends of the Spt7 subunit and the loss of the Spt8 subunit. The structural comparison of the wild-type SAGA with two deletion mutants positioned the DUB module and enabled the fitting of the available atomic models. The localization of the DUB module close to Gcn5 defines a chromatin-binding interface within SAGA, which could be demonstrated by the binding of nucleosome core particles. The TATA-box binding protein (TBP)-interacting subunit Spt8 was found to be located close to the DUB but in a different domain than Spt3, also known to contact TBP. A flexible protein arm brings both subunits close enough to interact simultaneously with TBP.
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6
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Abstract
The Swi2/Snf2 family ATPase Mot1 displaces TATA-binding protein (TBP) from DNA in vitro, but the global relationship between Mot1 and TBP in vivo is unclear. In particular, how Mot1 activates transcription is poorly understood. To address these issues, we mapped the distribution of Mot1 and TBP on native chromatin at base pair resolution. Mot1 and TBP binding sites coincide throughout the genome, and depletion of TBP results in a global decrease in Mot1 binding. We find evidence that Mot1 approaches TBP from the upstream direction, consistent with its in vitro mode of action. Strikingly, inactivation of Mot1 leads to both increases and decreases in TBP-genome association. Sites of TBP gain tend to contain robust TATA boxes, while sites of TBP loss contain poly(dA-dT) tracts that may contribute to nucleosome exclusion. Sites of TBP gain are associated with increased gene expression, while decreased TBP binding is associated with reduced gene expression. We propose that the action of Mot1 is required to clear TBP from intrinsically preferred (TATA-containing) binding sites, ensuring sufficient soluble TBP to bind intrinsically disfavored (TATA-less) sites.
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7
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Rodríguez-Torres AM, Lamas-Maceiras M, García-Díaz R, Freire-Picos MA. Structurally conserved and functionally divergent yeast Ssu72 phosphatases. FEBS Lett 2013; 587:2617-22. [PMID: 23831060 DOI: 10.1016/j.febslet.2013.06.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/18/2013] [Accepted: 06/25/2013] [Indexed: 12/25/2022]
Abstract
The eukaryotic Ssu72 factor is involved in several RNA biogenesis processes. It has phosphatase activity on the carboxy-terminal domain (CTD) of the major subunit of RNA polymerase II. The Kluyveromyces lactis Ssu72 (KlSsu72) shows in vitro phosphatase activity for the pNPP substrate, and this activity is inhibited by ortho-vanadate. The expression of KlSsu72 in Saccharomyces cerevisiae shows defective CTD serine5-P phosphatase activity and reveals the importance of Ssu72 for the normal CTD serine5-P levels at two growth states. The divergence is emphasised by the remarkable changes in RNA14 alternative 3'-end RNA processing, which are independent of the CTD serine5-P levels.
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Layer JH, Weil PA. Direct TFIIA-TFIID protein contacts drive budding yeast ribosomal protein gene transcription. J Biol Chem 2013; 288:23273-94. [PMID: 23814059 DOI: 10.1074/jbc.m113.486829] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We have previously shown that yeast TFIID provides coactivator function on the promoters of ribosomal protein-encoding genes (RPGs) by making direct contact with the transactivator repressor activator protein 1 (Rap1). Further, our structural studies of assemblies generated with purified Rap1, TFIID, and TFIIA on RPG enhancer-promoter DNA indicate that Rap1-TFIID interaction induces dramatic conformational rearrangements of enhancer-promoter DNA and TFIID-bound TFIIA. These data indicate a previously unknown yet critical role for yeast TFIIA in the integration of activator-TFIID contacts with promoter conformation and downstream preinitiation complex formation and/or function. Here we describe the use of systematic mutagenesis to define how specific TFIIA contacts contribute to these processes. We have verified that TFIIA is required for RPG transcription in vivo and in vitro, consistent with the existence of a critical Rap1-TFIIA-TFIID interaction network. We also identified essential points of contact for TFIIA and Rap1 within the Rap1 binding domain of the Taf4 subunit of TFIID. These data suggest a mechanism for how interactions between TFIID, TFIIA, and Rap1 contribute to the high rate of transcription initiation seen on RPGs in vivo.
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Affiliation(s)
- Justin H Layer
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0615, USA
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9
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Lake RJ, Fan HY. Structure, function and regulation of CSB: a multi-talented gymnast. Mech Ageing Dev 2013; 134:202-11. [PMID: 23422418 DOI: 10.1016/j.mad.2013.02.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/26/2013] [Accepted: 02/08/2013] [Indexed: 11/29/2022]
Abstract
The Cockayne syndrome complementation group B protein, CSB, plays pivotal roles in transcription regulation and DNA repair. CSB belongs to the SNF2/SWI2 ATP-dependent chromatin remodeling protein family, and studies from many laboratories have revealed that CSB has multiple activities and modes of regulation. To understand the underlying mechanisms of Cockayne syndrome, it is necessary to understand how the biochemical activities of CSB are used to carry out its biological functions. In this review, we summarize our current knowledge of the structure, function and regulation of CSB, and discuss how these properties can impact the biological functions of this chromatin remodeler.
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Affiliation(s)
- Robert J Lake
- Epigenetics Program, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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10
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Transcriptional regulation in Saccharomyces cerevisiae: transcription factor regulation and function, mechanisms of initiation, and roles of activators and coactivators. Genetics 2012; 189:705-36. [PMID: 22084422 DOI: 10.1534/genetics.111.127019] [Citation(s) in RCA: 239] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Here we review recent advances in understanding the regulation of mRNA synthesis in Saccharomyces cerevisiae. Many fundamental gene regulatory mechanisms have been conserved in all eukaryotes, and budding yeast has been at the forefront in the discovery and dissection of these conserved mechanisms. Topics covered include upstream activation sequence and promoter structure, transcription factor classification, and examples of regulated transcription factor activity. We also examine advances in understanding the RNA polymerase II transcription machinery, conserved coactivator complexes, transcription activation domains, and the cooperation of these factors in gene regulatory mechanisms.
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11
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Spedale G, Meddens CA, Koster MJE, Ko CW, van Hooff SR, Holstege FCP, Timmers HTM, Pijnappel WWMP. Tight cooperation between Mot1p and NC2β in regulating genome-wide transcription, repression of transcription following heat shock induction and genetic interaction with SAGA. Nucleic Acids Res 2011; 40:996-1008. [PMID: 21976730 PMCID: PMC3273795 DOI: 10.1093/nar/gkr784] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
TATA-binding protein (TBP) is central to the regulation of eukaryotic transcription initiation. Recruitment of TBP to target genes can be positively regulated by one of two basal transcription factor complexes: SAGA or TFIID. Negative regulation of TBP promoter association can be performed by Mot1p or the NC2 complex. Recent evidence suggests that Mot1p, NC2 and TBP form a DNA-dependent protein complex. Here, we compare the functions of Mot1p and NC2βduring basal and activated transcription using the anchor-away technique for conditional nuclear depletion. Genome-wide expression analysis indicates that both proteins regulate a highly similar set of genes. Upregulated genes were enriched for SAGA occupancy, while downregulated genes preferred TFIID binding. Mot1p and NC2β depletion during heat shock resulted in failure to downregulate gene expression after initial activation, which was accompanied by increased TBP and RNA pol II promoter occupancies. Depletion of Mot1p or NC2β displayed preferential synthetic lethality with the TBP-interaction module of SAGA. Our results support the model that Mot1p and NC2β directly cooperate in vivo to regulate TBP function, and that they are involved in maintaining basal expression levels as well as in resetting gene expression after induction by stress.
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Affiliation(s)
- Gianpiero Spedale
- Molecular Cancer Research, Netherlands Proteomics Centre, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
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12
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Distinct role of Mediator tail module in regulation of SAGA-dependent, TATA-containing genes in yeast. EMBO J 2011; 31:44-57. [PMID: 21971086 DOI: 10.1038/emboj.2011.362] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Accepted: 09/07/2011] [Indexed: 11/08/2022] Open
Abstract
The evolutionarily conserved Mediator complex is required for transcription of nearly all RNA Pol II-dependent promoters, with the tail module serving to recruit Mediator to active promoters in current models. However, transcriptional dependence on tail module subunits varies in a gene-specific manner, and the generality of the tail module requirement for transcriptional activation has not been explored. Here, we show that tail module subunits function redundantly to recruit Mediator to promoters in yeast, and transcriptome analysis shows stronger effects on genome-wide expression in a double-tail subunit deletion mutant than in single-subunit deletion mutants. Unexpectedly, TATA-containing and SAGA-dependent genes were much more affected by impairment of tail module function than were TFIID-dependent genes. Consistent with this finding, Mediator and preinitiation complex association with SAGA-dependent promoters is substantially reduced in gal11/med15Δ med3Δ yeast, whereas association of TBP, Pol II, and other Mediator modules with TFIID-dependent genes is largely independent of the tail module. Thus, we have identified a connection between the Mediator tail module and the division of promoter dependence between TFIID and SAGA.
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13
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Viswanathan R, Auble DT. One small step for Mot1; one giant leap for other Swi2/Snf2 enzymes? BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1809:488-96. [PMID: 21658482 DOI: 10.1016/j.bbagrm.2011.05.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 05/14/2011] [Accepted: 05/20/2011] [Indexed: 12/13/2022]
Abstract
The TATA-binding protein (TBP) is a major target for transcriptional regulation. Mot1, a Swi2/Snf2-related ATPase, dissociates TBP from DNA in an ATP dependent process. The experimental advantages of this relatively simple reaction have been exploited to learn more about how Swi2/Snf2 ATPases function biochemically. However, many unanswered questions remain and fundamental aspects of the Mot1 mechanism are still under debate. Here, we review the available data and integrate the results with structural and biochemical studies of related enzymes to derive a model for Mot1's catalytic action consistent with the broad literature on enzymes in this family. We propose that the Mot1 ATPase domain is tethered to TBP by a flexible, spring-like linker of alpha helical hairpins. The linker juxtaposes the ATPase domain such that it can engage duplex DNA on one side of the TBP-DNA complex. This allows the ATPase to employ short-range, nonprocessive ATP-driven DNA tracking to pull or push TBP off its DNA site. DNA translocation is a conserved property of ATPases in the broader enzyme family. As such, the model explains how a structurally and functionally conserved ATPase domain has been put to use in a very different context than other enzymes in the Swi2/Snf2 family. This article is part of a Special Issue entitled:Snf2/Swi2 ATPase structure and function.
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Affiliation(s)
- Ramya Viswanathan
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, USA
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14
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Domains of Tra1 important for activator recruitment and transcription coactivator functions of SAGA and NuA4 complexes. Mol Cell Biol 2010; 31:818-31. [PMID: 21149579 DOI: 10.1128/mcb.00687-10] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Tra1 protein is a direct transcription activator target that is essential for coactivator function of both the SAGA and NuA4 histone acetyltransferase (HAT) complexes. The ∼400-kDa Saccharomyces cerevisiae Tra1 polypeptide and its human counterpart TRRAP contain 67 or 68 tandem α-helical HEAT and TPR protein repeats that extend from the N terminus to the conserved yet catalytically inactive phosphatidylinositol 3-kinase (PI3K) domain. We generated a series of mutations spanning the length of the protein and assayed for defects in transcription, coactivator recruitment, and histone acetylation at SAGA- and NuA4-dependent genes. Inviable TRA1 mutants all showed defects in SAGA and NuA4 complex stability, suggesting that similar surfaces of Tra1 mediate assembly of these two very different coactivator complexes. Nearly all of the viable Tra1 mutants showed transcription defects that fell into one of three classes: (i) defective recruitment to promoters, (ii) reduced stability of the SAGA and NuA4 HAT modules, or (iii) normal recruitment of Tra1-associated subunits but reduced HAT activity in vivo. Our results show that Tra1 recruitment at Gcn4-dependent and Rap1-dependent promoters requires the same regions of Tra1 and that separate regions of Tra1 contribute to the HAT activity and stability of the SAGA and NuA4 HAT modules.
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15
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Abstract
The cellular role of the Ada2 coactivator is currently understood in the context of the SAGA histone acetyltransferase (HAT) complex, where Ada2 increases the HAT activity of Gcn5 and interacts with transcriptional activators. Here we report a new function for Ada2 in promoting transcriptional silencing at telomeres and ribosomal DNA. This silencing function is the first characterized role for Ada2 distinct from its involvement with Gcn5. Ada2 binds telomeric chromatin and the silencing protein Sir2 in vivo. Loss of ADA2 causes the spreading of Sir2 and Sir3 into subtelomeric regions and decreased histone H4 K16 acetylation. This previously uncharacterized boundary activity of Ada2 is functionally similar to, but mechanistically distinct from, that of the MYST family HAT Sas2. Mounting evidence in the literature indicates that boundary activities create chromosomal domains important for regulating gene expression in response to environmental changes. Consistent with this, we show that upon nutritional changes, Ada2 occupancy increases at a subtelomeric region proximal to a SAGA-inducible gene and causes derepression of a silenced telomeric reporter gene. Thus, Ada2, likely in the context of SAGA, is positioned at chromosomal termini to participate in both transcriptional repression and activation in response to nutrient signaling.
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Seoane S, Lamas-Maceiras M, Rodríguez-Torres AM, Freire-Picos MA. Involvement of Pta1, Pcf11 and a KlCYC1 AU-rich element in alternative RNA 3'-end processing selection in yeast. FEBS Lett 2009; 583:2843-8. [PMID: 19646984 DOI: 10.1016/j.febslet.2009.07.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 07/23/2009] [Accepted: 07/23/2009] [Indexed: 11/24/2022]
Abstract
This work reports the involvement of yeast RNA processing factors Pta1 and Pcf11 in alternative 3'-end RNA processing. The pta1-1 and pcf11-2 mutations changed the predominance of KlCYC1 1.14 and 1.5 kb transcript isoforms. Mutation of the KlCYC1 3'-UTR AU-rich sequence at positions 679-690 (mutant M1) altered transcript predominance. Moreover, expression of M1 in the yeast mutants partially suppressed their effects in the predominance pattern. The combination of the M1 and M2 (694-698 deletion) mutations abolished the alternative processing. Pta1 involvement in this selection was confirmed using the Pta1-td degron strain.
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Affiliation(s)
- Silvia Seoane
- Universidade da Coruña, Facultad de Ciencias, Campus da Zapateira S/N, 15071 A Coruña, Spain
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17
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Mohibullah N, Hahn S. Site-specific cross-linking of TBP in vivo and in vitro reveals a direct functional interaction with the SAGA subunit Spt3. Genes Dev 2009; 22:2994-3006. [PMID: 18981477 DOI: 10.1101/gad.1724408] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The TATA-binding protein (TBP) is critical for transcription by all three nuclear RNA polymerases. In order to identify factors that interact with TBP, the nonnatural photoreactive amino acid rho-benzoyl-phenylalanine (BPA) was substituted onto the surface of Saccharomyces cerevisiae TBP in vivo. Cross-linking of these TBP derivatives in isolated transcription preinitiation complexes or in living cells reveals physical interactions of TBP with transcriptional coregulator subunits and with the general transcription factor TFIIA. Importantly, the results show a direct interaction between TBP and the SAGA coactivator subunits Spt3 and Spt8. Mutations on the Spt3-interacting surface of TBP significantly reduce the interaction of TBP with SAGA, show a corresponding decrease in transcription activation, and fail to recruit TBP to a SAGA-dependent promoter, demonstrating that the direct interaction of these factors is important for activated transcription. These results prove a key prediction of the model for stimulation of transcription at SAGA-dependent genes via Spt3. Our cross-linking data also significantly extend the known surfaces of TBP that directly interact with the transcriptional regulator Mot1 and the general transcription factor TFIIA.
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Affiliation(s)
- Neeman Mohibullah
- Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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18
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Auble DT. The dynamic personality of TATA-binding protein. Trends Biochem Sci 2008; 34:49-52. [PMID: 19038550 DOI: 10.1016/j.tibs.2008.10.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Revised: 10/23/2008] [Accepted: 10/27/2008] [Indexed: 11/26/2022]
Abstract
TATA-binding protein (TBP) is a central component of the transcription apparatus and its association with promoters is dynamically regulated genome-wide. Recent work has shed new light on the functional specificity of Mot1 and NC2, two factors that control TBP distribution and activity. These studies underscore how regulation of TBP globally influences fundamental aspects of gene expression, including the balance of transcriptional output from different types of promoters, and the amplitude and timing of gene activation.
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Affiliation(s)
- David T Auble
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, USA.
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19
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van Werven FJ, van Bakel H, van Teeffelen HAAM, Altelaar AFM, Koerkamp MG, Heck AJR, Holstege FCP, Timmers HTM. Cooperative action of NC2 and Mot1p to regulate TATA-binding protein function across the genome. Genes Dev 2008; 22:2359-69. [PMID: 18703679 DOI: 10.1101/gad.1682308] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Promoter recognition by TATA-binding protein (TBP) is an essential step in the initiation of RNA polymerase II (pol II) mediated transcription. Genetic and biochemical studies in yeast have shown that Mot1p and NC2 play important roles in inhibiting TBP activity. To understand how TBP activity is regulated in a genome-wide manner, we profiled the binding of TBP, NC2, Mot1p, TFIID, SAGA, and pol II across the yeast genome using chromatin immunoprecipitation (ChIP)-chip for cells in exponential growth and during reprogramming of transcription. We find that TBP, NC2, and Mot1p colocalize at transcriptionally active pol II core promoters. Relative binding of NC2alpha and Mot1p is higher at TATA promoters, whereas NC2beta has a preference for TATA-less promoters. In line with the ChIP-chip data, we isolated a stable TBP-NC2-Mot1p-DNA complex from chromatin extracts. ATP hydrolysis releases NC2 and DNA from the Mot1p-TBP complex. In vivo experiments indicate that promoter dissociation of TBP and NC2 is highly dynamic, which is dependent on Mot1p function. Based on these results, we propose that NC2 and Mot1p cooperate to dynamically restrict TBP activity on transcribed promoters.
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Affiliation(s)
- Folkert J van Werven
- Department of Physiological Chemistry, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
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Arnett DR, Jennings JL, Tabb DL, Link AJ, Weil PA. A proteomics analysis of yeast Mot1p protein-protein associations: insights into mechanism. Mol Cell Proteomics 2008; 7:2090-106. [PMID: 18596064 DOI: 10.1074/mcp.m800221-mcp200] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Yeast Mot1p, a member of the Snf2 ATPase family of proteins, is a transcriptional regulator that has the unusual ability to both repress and activate mRNA gene transcription. To identify interactions with other proteins that may assist Mot1p in its regulatory processes, Mot1p was purified from replicate yeast cell extracts, and Mot1p-associated proteins were identified by coupled multidimensional liquid chromatography and tandem mass spectrometry. Using this approach we generated a catalog of Mot1p-interacting proteins. Mot1p interacts with a range of transcriptional co-regulators as well as proteins involved in chromatin remodeling. We propose that interaction with such a wide range of proteins may be one mechanism through which Mot1p subserves its roles as a transcriptional activator and repressor.
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Affiliation(s)
- Diana R Arnett
- Department of Molecular Physiology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA
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21
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Characterization of new Spt3 and TATA-binding protein mutants of Saccharomyces cerevisiae: Spt3 TBP allele-specific interactions and bypass of Spt8. Genetics 2008; 177:2007-17. [PMID: 18073420 DOI: 10.1534/genetics.107.081976] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Spt-Ada-Gcn5-acetyltransferase (SAGA) complex of Saccharomyces cerevisiae is a multifunctional coactivator complex that has been shown to regulate transcription by distinct mechanisms. Previous results have shown that the Spt3 and Spt8 components of SAGA regulate initiation of transcription of particular genes by controlling the level of TATA-binding protein (TBP/Spt15) associated with the TATA box. While biochemical evidence exists for direct Spt8-TBP interactions, similar evidence for Spt3-TBP interactions has been lacking. To learn more about Spt3-TBP interactions in vivo, we have isolated a new class of spt3 mutations that cause a dominant-negative phenotype when overexpressed. These mutations all cluster within a conserved region of Spt3. The isolation of extragenic suppressors of one of these spt3 mutations has identified two new spt15 mutations that show allele-specific interactions with spt3 mutations with respect to transcription and the recruitment of TBP to particular promoters. In addition, these new spt15 mutations partially bypass an spt8 null mutation. Finally, we have examined the level of SAGA-TBP physical interaction in these mutants. While most spt3, spt8, and spt15 mutations do not alter SAGA-TBP interactions, one spt3 mutation, spt3-401, causes a greatly increased level of SAGA-TBP physical association. These results, taken together, suggest that a direct Spt3-TBP interaction is required for normal TBP levels at Spt3-dependent promoters in vivo.
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22
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Singh BN, Hampsey M. A transcription-independent role for TFIIB in gene looping. Mol Cell 2007; 27:806-16. [PMID: 17803944 DOI: 10.1016/j.molcel.2007.07.013] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 06/12/2007] [Accepted: 07/11/2007] [Indexed: 01/05/2023]
Abstract
Recent studies demonstrated the existence of gene loops that juxtapose the promoter and terminator regions of genes with exceptionally long ORFs in yeast. Here we report that looping is not idiosyncratic to long genes but occurs between the distal ends of genes with ORFs as short as 1 kb. Moreover, looping is dependent upon the general transcription factor TFIIB: the E62K (glutamic acid 62 --> lysine) form of TFIIB adversely affects looping at every gene tested, including BLM10, SAC3, GAL10, SEN1, and HEM3. TFIIB crosslinks to both the promoter and terminator regions of the PMA1 and BLM10 genes, and its association with the terminator, but not the promoter, is adversely affected by E62K and by depletion of the Ssu72 component of the CPF 3' end processing complex, and is independent of TBP. We propose a model suggesting that TFIIB binds RNAP II at the terminator, which in turn associates with the promoter scaffold.
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Affiliation(s)
- Badri Nath Singh
- Department of Biochemistry, Division of Nucleic Acids Enzymology, Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854, USA
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23
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James N, Landrieux E, Collart MA. A SAGA-independent function of SPT3 mediates transcriptional deregulation in a mutant of the Ccr4-not complex in Saccharomyces cerevisiae. Genetics 2007; 177:123-35. [PMID: 17660549 PMCID: PMC2013695 DOI: 10.1534/genetics.107.076299] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The conserved multi-subunit Ccr4-Not complex regulates gene expression in diverse ways. In this work, we characterize the suppression of temperature sensitivity associated with a mutation in the gene encoding the scaffold subunit of the Ccr4-Not complex, NOT1, by the deletion of SPT3. We determine that the deletion of SPT3, but not the deletion of genes encoding other subunits of the SAGA complex, globally suppresses transcriptional defects of not1-2. We find that transcriptional activation in not1-2 is associated with increased binding of TFIID and SAGA at promoters of upregulated genes, and this is suppressed by the deletion of SPT3. Interestingly, Spt3p-dependent activation of transcription occurs in not1-2 even if the SAGA complex is disrupted by the deletion of SPT7 that encodes a subunit of SAGA required for its integrity. Consistent with a SAGA-independent function of Spt3p, the deletion of SPT3 displays synthetic phenotypes when combined with a deletion of SPT7. Taken together, our results provide a new view of the Spt3 protein by identifying a SAGA-independent function of this protein that is functionally linked to the Ccr4-Not complex.
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Affiliation(s)
- Nicole James
- Department of Microbiology and Molecular Medicine, University of Geneva Medical School, Geneva 1211, Switzerland
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24
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Høiby T, Zhou H, Mitsiou DJ, Stunnenberg HG. A facelift for the general transcription factor TFIIA. ACTA ACUST UNITED AC 2007; 1769:429-36. [PMID: 17560669 DOI: 10.1016/j.bbaexp.2007.04.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 04/20/2007] [Accepted: 04/24/2007] [Indexed: 10/23/2022]
Abstract
TFIIA was classified as a general transcription factor when it was first identified. Since then it has been debated to what extent it can actually be regarded as "general". The most notable feature of TFIIA is the proteolytical cleavage of the TFIIAalphabeta into a TFIIAalpha and TFIIAbeta moiety which has long remained a mystery. Recent studies have showed that TFIIA is cleaved by Taspase1 which was initially identified as the protease for the proto-oncogene MLL. Cleavage of TFIIA does not appear to serve as a step required for its activation as the uncleaved TFIIA in the Taspase1 knock-outs adequately support bulk transcription. Instead, cleavage of TFIIA seems to affect its turn-over and may be a part of an intricate degradation mechanism that allows fine-tuning of cellular levels of TFIIA. Cleavage might also be responsible for switching transcription program as the uncleaved and cleaved TFIIA might have distinct promoter specificity during development and differentiation. This review will focus on functional characteristics of TFIIA and discuss novel insights in the role of this elusive transcription factor.
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Affiliation(s)
- Torill Høiby
- NCMLS, Department of Molecular Biology, 191, Radboud University of Nijmegen, PO Box 91001, 6500 HB Nijmegen, The Netherlands
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25
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Dasgupta A, Sprouse RO, French S, Aprikian P, Hontz R, Juedes SA, Smith JS, Beyer AL, Auble DT. Regulation of rRNA synthesis by TATA-binding protein-associated factor Mot1. Mol Cell Biol 2007; 27:2886-96. [PMID: 17296733 PMCID: PMC1899949 DOI: 10.1128/mcb.00054-07] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mot1 is an essential, conserved, TATA-binding protein (TBP)-associated factor in Saccharomyces cerevisiae with well-established roles in the global control of RNA polymerase II (Pol II) transcription. Previous results have suggested that Mot1 functions exclusively in Pol II transcription, but here we report a novel role for Mot1 in regulating transcription by RNA polymerase I (Pol I). In vivo, Mot1 is associated with the ribosomal DNA, and loss of Mot1 results in decreased rRNA synthesis. Consistent with a direct role for Mot1 in Pol I transcription, Mot1 also associates with the Pol I promoter in vitro in a reaction that depends on components of the Pol I general transcription machinery. Remarkably, in addition to Mot1's role in initiation, rRNA processing is delayed in mot1 cells. Taken together, these results support a model in which Mot1 affects the rate and efficiency of rRNA synthesis by both direct and indirect mechanisms, with resulting effects on transcription activation and the coupling of rRNA synthesis to processing.
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MESH Headings
- Adenosine Triphosphatases/metabolism
- Chromatin/metabolism
- DNA Helicases/metabolism
- DNA, Ribosomal/ultrastructure
- Gene Expression Regulation, Fungal
- Genes, Fungal
- Mutation/genetics
- Promoter Regions, Genetic/genetics
- Protein Transport
- RNA Polymerase I/metabolism
- RNA Processing, Post-Transcriptional/genetics
- RNA, Ribosomal/biosynthesis
- RNA, Ribosomal/genetics
- RNA, Ribosomal/ultrastructure
- Repetitive Sequences, Nucleic Acid/genetics
- Saccharomyces cerevisiae/cytology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Saccharomyces cerevisiae/ultrastructure
- Saccharomyces cerevisiae Proteins/metabolism
- TATA-Binding Protein Associated Factors/metabolism
- Transcription Factors/metabolism
- Transcription, Genetic
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Affiliation(s)
- Arindam Dasgupta
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, 1300 Jefferson Park Avenue, Charlottesville, Virginia 22908-0733, USA.
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26
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Morillo-Huesca M, Vanti M, Chávez S. A simple in vivo assay for measuring the efficiency of gene length-dependent processes in yeast mRNA biogenesis. FEBS J 2006; 273:756-69. [PMID: 16441662 DOI: 10.1111/j.1742-4658.2005.05108.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have developed a simple reporter assay useful for detection and analysis of mutations and agents influencing mRNA biogenesis in a gene length-dependent manner. We have shown that two transcription units sharing the same promoter, terminator and open reading frame, but differing in the length of their 3'-untranslated regions, are differentially influenced by mutations affecting factors that play a role in transcription elongation or RNA processing all along the transcription units. In contrast, those mutations impairing the initial steps of transcription, but not affecting later steps of mRNA biogenesis, influence equally the expression of the reporters, independently of the length of their 3'-untranslated regions. The ratio between the product levels of the two transcription units is an optimal parameter with which to estimate the efficiency of gene length-dependent processes in mRNA biogenesis. The presence of a phosphatase-encoding open reading frame in the two transcription units makes it very easy to calculate this ratio in any mutant or physiological condition. Interestingly, using this assay, we have shown that mutations in components of the SAGA complex affect the level of mRNA in a transcript length-dependent fashion, suggesting a role for SAGA in transcription elongation. The use of this assay allows the identification and/or characterization of new mutants and drugs affecting transcription elongation and other related processes.
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27
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Sprouse RO, Brenowitz M, Auble DT. Snf2/Swi2-related ATPase Mot1 drives displacement of TATA-binding protein by gripping DNA. EMBO J 2006; 25:1492-504. [PMID: 16541100 PMCID: PMC1440317 DOI: 10.1038/sj.emboj.7601050] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Accepted: 02/20/2006] [Indexed: 11/09/2022] Open
Abstract
Mot1 is a conserved Snf2/Swi2-related transcriptional regulator that uses ATP hydrolysis to displace TATA-binding protein (TBP) from DNA. Several models of the enzymatic mechanism have been proposed, including Mot1-catalyzed distortion of TBP structure, competition between Mot1 and DNA for the TBP DNA-binding surface, and ATP-driven translocation of Mot1 along DNA. Here, DNase I footprinting studies provide strong support for a 'DNA-based' mechanism of Mot1, which we propose involves ATP-driven DNA translocation. Mot1 forms an asymmetric complex with the TBP core domain (TBPc)-DNA complex, contacting DNA both upstream and within the major groove of the TATA Box. Contact with upstream DNA is required for Mot1-mediated displacement of TBPc from DNA. Using the SsoRad54-DNA complex as a model, DNA-binding residues in Mot1 were identified that are critical for Mot1-TBPc-DNA complex formation and catalytic activity, thus placing Mot1 mechanistically within the helicase superfamily. We also report a novel ATP-independent TBPc displacement activity for Mot1 and describe conformational heterogeneity in the Mot1 ATPase, which is likely a general feature of other enzymes in this class.
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Affiliation(s)
- Rebekka O Sprouse
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA, USA
| | - Michael Brenowitz
- Department of Biochemistry, The Albert Einstein College of Medicine, Bronx, NY, USA
| | - David T Auble
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, 1300 Jefferson Park Avenue, Room 6213, Charlottesville, VA 22908-0733, USA. Tel.: +1 434 243 2629; Fax: +1 434 924 5069; E-mail:
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28
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Zhelkovsky A, Tacahashi Y, Nasser T, He X, Sterzer U, Jensen TH, Domdey H, Moore C. The role of the Brr5/Ysh1 C-terminal domain and its homolog Syc1 in mRNA 3'-end processing in Saccharomyces cerevisiae. RNA (NEW YORK, N.Y.) 2006; 12:435-45. [PMID: 16431986 PMCID: PMC1383582 DOI: 10.1261/rna.2267606] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The cleavage/polyadenylation factor (CPF) of Saccharomyces cerevisiae is thought to provide the catalytic activities of the mRNA 3'-end processing machinery, which include endonucleolytic cleavage at the poly(A) site, followed by synthesis of an adenosine polymer onto the new 3'-end by the CPF subunit Pap1. Because of similarity to other nucleases in the metallo-beta-lactamase family, the Brr5/Ysh1 subunit has been proposed to be the endonuclease. The C-terminal domain of Brr5 lies outside of beta-lactamase homology, and its function has not been elucidated. We show here that this region of Brr5 is necessary for cell viability and mRNA 3'-end processing. It is highly homologous to another CPF subunit, Syc1. Syc1 is not essential, but its removal improves the growth of other processing mutants at restrictive temperatures and restores in vitro processing activity to cleavage/ polyadenylation-defective brr5-1 extract. Our findings suggest that Syc1, by mimicking the essential Brr5 C-terminus, serves as a negative regulator of mRNA 3'-end formation.
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Affiliation(s)
- Alexander Zhelkovsky
- Department of Molecular Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
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29
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Horwitz AA, Sankaran S, Parvin JD. Direct stimulation of transcription initiation by BRCA1 requires both its amino and carboxyl termini. J Biol Chem 2006; 281:8317-20. [PMID: 16473884 DOI: 10.1074/jbc.c500475200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Published experiments suggest that BRCA1 interaction with RNAPII and regulation of a number of target genes may be central to its role as a tumor suppressor. Previous in vivo and in vitro work has implicated the carboxyl terminus of BRCA1 in transcriptional stimulation, but the mechanism of action remains unknown, and whether the full-length protein stimulates transcription is controversial. BRCA1 interacts with a number of enhancer-binding transcriptional activators, suggesting that these factors recruit BRCA1 to promoters, where it stimulates RNA synthesis. To investigate whether BRCA1 has intrinsic transcriptional activity, we established a fully purified transcription assay. We demonstrate here that BRCA1 stimulates transcription initiation across a range of promoters. Both the amino and carboxyl termini of BRCA1 are required for this activity, but the BRCA1-binding partner, BARD1, is not. Our data support a model whereby BRCA1 stabilizes productive preinitiation complexes and thus stimulates transcription.
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Affiliation(s)
- Andrew A Horwitz
- Program in Biology and Biomedical Sciences, Harvard Medical School, Boston, Massachusetts 02115, USA
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30
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Wang Z, Jones GM, Prelich G. Genetic analysis connects SLX5 and SLX8 to the SUMO pathway in Saccharomyces cerevisiae. Genetics 2005; 172:1499-509. [PMID: 16387868 PMCID: PMC1456262 DOI: 10.1534/genetics.105.052811] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
MOT1 encodes an essential ATPase that functions as a general transcriptional regulator in vivo by modulating TATA-binding protein (TBP) DNA-binding activity. Although MOT1 was originally identified both biochemically and in several genetic screens as a transcriptional repressor, a combination of subsequent genetic, chromatin immunoprecipitation, and microarray analysis suggested that MOT1 might also have an additional role in vivo as a transcriptional activator. To better understand the role(s) of MOT1 in vivo, we selected for genomic suppressors of a mot1 temperature-sensitive mutation. This selection identified mutations in SPT15 (TBP) and BUR6, both of which are clearly linked with MOT1 at the functional level. The vast majority of the suppressor mutations, however, unexpectedly occurred in six genes that encode known components of the SUMO pathway and in two other genes with unknown functions, SLX5 and SLX8. Additional results presented here, including extensive synthetic lethality observed between slx5delta and slx8delta and SUMO pathway mutations, suggest that SLX5 and SLX8 are new components or regulators of the SUMO pathway and that SUMO modification might have a general role in transcriptional regulation as part of the TBP regulatory network.
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Affiliation(s)
- Zheng Wang
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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31
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Biswas D, Yu Y, Mitra D, Stillman DJ. Genetic interactions between Nhp6 and Gcn5 with Mot1 and the Ccr4-Not complex that regulate binding of TATA-binding protein in Saccharomyces cerevisiae. Genetics 2005; 172:837-49. [PMID: 16272410 PMCID: PMC1456248 DOI: 10.1534/genetics.105.050245] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Our previous work suggests that the Nhp6 HMGB protein stimulates RNA polymerase II transcription via the TATA-binding protein TBP and that Nhp6 functions in the same functional pathway as the Gcn5 histone acetyltransferase. In this report we examine the genetic relationship between Nhp6 and Gcn5 with the Mot1 and Ccr4-Not complexes, both of which have been implicated in regulating DNA binding by TBP. We find that combining either a nhp6ab or a gcn5 mutation with mot1, ccr4, not4, or not5 mutations results in lethality. Combining spt15 point mutations (in TBP) with either mot1 or ccr4 also results in either a growth defect or lethality. Several of these synthetic lethalities can be suppressed by overexpression of TFIIA, TBP, or Nhp6, suggesting that these genes facilitate formation of the TBP-TFIIA-DNA complex. The growth defect of a not5 mutant can be suppressed by a mot1 mutant. HO gene expression is reduced by nhp6ab, gcn5, or mot1 mutations, and the additive decreases in HO mRNA levels in nhp6ab mot1 and gcn5 mot1 strains suggest different modes of action. Chromatin immunoprecipitation experiments show decreased binding of TBP to promoters in mot1 mutants and a further decrease when combined with either nhp6ab or gcn5 mutations.
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Affiliation(s)
- Debabrata Biswas
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA
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32
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Biswas D, Yu Y, Prall M, Formosa T, Stillman DJ. The yeast FACT complex has a role in transcriptional initiation. Mol Cell Biol 2005; 25:5812-22. [PMID: 15987999 PMCID: PMC1168812 DOI: 10.1128/mcb.25.14.5812-5822.2005] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A crucial step in eukaryotic transcriptional initiation is recognition of the promoter TATA by the TATA-binding protein (TBP), which then allows TFIIA and TFIIB to be recruited. However, nucleosomes block the interaction between TBP and DNA. We show that the yeast FACT complex (yFACT) promotes TBP binding to a TATA box in chromatin both in vivo and in vitro. The SPT16 gene encodes a subunit of yFACT, and we show that certain spt16 mutations are synthetically lethal with TBP mutants. Some of these genetic defects can be suppressed by TFIIA overexpression, strongly suggesting a role for yFACT in TBP-TFIIA complex formation in vivo. Mutations in the TOA2 subunit of TFIIA that disrupt TBP-TFIIA complex formation in vitro are also synthetically lethal with spt16. In some cases this spt16 toa2 lethality is suppressed by overexpression of TBP or the Nhp6 architectural transcription factor that is also a component of yFACT. The Spt3 protein in the SAGA complex has been shown to regulate TBP binding at certain promoters, and we show that some spt16 phenotypes can be suppressed by spt3 mutations. Chromatin immunoprecipitations show TBP binding to promoters is reduced in single spt16 and spt3 mutants but increases in the spt16 spt3 double mutant, reflecting the mutual suppression seen in the genetic assays. Finally, in vitro studies show that yFACT promotes TBP binding to a TATA sequence within a reconstituted nucleosome in a TFIIA-dependent manner. Thus, yFACT functions in establishing transcription initiation complexes in addition to the previously described role in elongation.
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Affiliation(s)
- Debabrata Biswas
- Department of Pathology, University of Utah Health Sciences Center, 30 North 1900 East, Salt Lake City, Utah 84132-2501, USA
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33
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van Oevelen CJC, van Teeffelen HAAM, Timmers HTM. Differential requirement of SAGA subunits for Mot1p and Taf1p recruitment in gene activation. Mol Cell Biol 2005; 25:4863-72. [PMID: 15923605 PMCID: PMC1140607 DOI: 10.1128/mcb.25.12.4863-4872.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcription activation in yeast (Saccharomyces cerevisiae) involves ordered recruitment of transcription factor complexes, such as TFIID, SAGA, and Mot1p. Previously, we showed that both Mot1p and Taf1p are recruited to the HXT2 and HXT4 genes, which encode hexose transporter proteins. Here, we show that SAGA also binds to the HXT2 and HXT4 promoters and plays a pivotal role in the recruitment of Mot1p and Taf1p. The deletion of either SPT3 or SPT8 reduces Mot1p binding to HXT2 and HXT4. Surprisingly, the deletion of GCN5 reduces Taf1p binding to both promoters. When GCN5 is deleted in spt3Delta or spt8Delta strains, neither Mot1p nor Taf1p binds, and this results in a diminished recruitment of TATA binding protein and polymerase II to the HXT4 but not the HXT2 promoter. This is reflected by the SAGA-dependent expression of HXT4. In contrast, SAGA-independent induction of HXT2 suggests a functional redundancy with other factors. A functional interplay of different SAGA subunits with Mot1p and Taf1p was supported by phenotypic analysis of MOT1 SAGA or TAF1/SAGA double mutant strains, which revealed novel genetic interactions between MOT1 and SPT8 and between TAF1 and GCN5. In conclusion, our data demonstrate functional links between SAGA, Mot1p, and TFIID in HXT gene regulation.
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Affiliation(s)
- Chris J C van Oevelen
- Department of Physiological Chemistry, Division of Biomedical Genetics, University Medical Centre Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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34
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Dasgupta A, Juedes SA, Sprouse RO, Auble DT. Mot1-mediated control of transcription complex assembly and activity. EMBO J 2005; 24:1717-29. [PMID: 15861138 PMCID: PMC1142579 DOI: 10.1038/sj.emboj.7600646] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2004] [Accepted: 03/14/2005] [Indexed: 11/09/2022] Open
Abstract
Mot1 is an essential Snf2/Swi2-related ATPase and TATA-binding protein (TBP)-associated factor (TAF). In vitro, Mot1 utilizes ATP hydrolysis to disrupt TBP-DNA complexes, but the relationship of this activity to Mot1's in vivo function is unclear. Chromatin immunoprecipitation was used to determine how Mot1 affects the assembly of preinitiation complexes (PICs) at Mot1-controlled promoters in vivo. We find that the Mot1-repressed HSP26 and INO1 promoters are both regulated by TBP recruitment; inactivation of Mot1 leads to increased PIC formation coincident with derepression of transcription. For the Mot1-activated genes BNA1 and URA1, inactivation of Mot1 also leads, remarkably, to increased TBP binding to the promoters, despite the fact that transcription of these genes is obliterated in mot1 cells. In contrast, levels of Taf1, TFIIB, and RNA polymerase II are reduced at Mot1-activated promoters in mot1 cells. These results suggest that Mot1-mediated displacement of TBP underlies its mechanism of repression and activation at these genes. We suggest that at activated promoters, Mot1 disassembles transcriptionally inactive TBP, thereby facilitating the formation of a TBP complex that supports functional PIC assembly.
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Affiliation(s)
- Arindam Dasgupta
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA, USA
| | - Sarah A Juedes
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA, USA
| | - Rebekka O Sprouse
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA, USA
| | - David T Auble
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, 1300 Jefferson Park Avenue, Room 6213, Charlottesville, VA 22908-0733, USA. Tel.: +1 434 243 2629; Fax: +1 434 924 5069; E-mail:
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35
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Klejman MP, Pereira LA, van Zeeburg HJT, Gilfillan S, Meisterernst M, Timmers HTM. NC2alpha interacts with BTAF1 and stimulates its ATP-dependent association with TATA-binding protein. Mol Cell Biol 2004; 24:10072-82. [PMID: 15509807 PMCID: PMC525489 DOI: 10.1128/mcb.24.22.10072-10082.2004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcriptional activity of the TATA-binding protein (TBP) is controlled by a variety of proteins. The BTAF1 protein (formerly known as TAF(II)170/TAF-172 and the human ortholog of Saccharomyces cerevisiae Mot1p) and the NC2 complex composed of NC2alpha (DRAP1) and NC2beta (Dr1) are able to bind to TBP directly and regulate RNA polymerase II transcription both positively and negatively. Here, we present evidence that the NC2alpha subunit interacts with BTAF1. In contrast, the NC2beta subunit is not able to associate with BTAF1 and seems to interfere with the BTAF1-TBP interaction. Addition of NC2alpha or the NC2 complex can stimulate the ability of BTAF1 to interact with TBP. This function is dependent on the presence of ATP in cell extracts but does not involve the ATPase activity of BTAF1 nor phosphorylation of NC2alpha. Together, our results constitute the first evidence of the physical cooperation between BTAF1 and NC2alpha in TBP regulation and provide a framework to understand transcription functions of NC2alpha and NC2beta in vivo.
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Affiliation(s)
- Marcin P Klejman
- Department of Physiological Chemistry, Division of Biomedical Genetics, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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36
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Zanton SJ, Pugh BF. Changes in genomewide occupancy of core transcriptional regulators during heat stress. Proc Natl Acad Sci U S A 2004; 101:16843-8. [PMID: 15548603 PMCID: PMC534727 DOI: 10.1073/pnas.0404988101] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Organisms respond to heat stress by reprogramming gene expression. In Saccharomyces cerevisiae, heat-induced genes tend to be regulated by factors that belong to the Spt-Ada-Gcn5 acetyltransferase (SAGA) transcription regulatory pathway, whereas heat-repressed genes tend to be regulated by a parallel pathway involving transcription factor IID (TFIID). Here, we examine whether heat stress affects the occupancy of representative factors of each pathway at promoter regions throughout the yeast genome. Representatives of the SAGA pathway include the TATA binding protein, Spt3, and Mot1. Representatives of the TFIID pathway include the TATA binding protein, TAF1, and Bdf1. We find that heat stress causes disassembly of the TFIID pathway at genes that are inhibited by stress. In contrast, heat induces assembly of the SAGA pathway at stress-induced genes, although many also assemble along the TFIID pathway. Other genes were found to assemble almost exclusively along the TFIID pathway. Strikingly, these genes are lowly transcribed and are generally not induced. Thus, heat stress leads to factor assembly along each pathway but with distinct transcriptional outcomes. Further investigation of these pathways reveals that Bdf1 and Mot1 negatively regulate the SAGA pathway in different ways. The findings suggest that Bdf1 blocks assembly, whereas Mot1 promotes disassembly of the transcription machinery.
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Affiliation(s)
- Sara J Zanton
- Center for Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
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37
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Eriksson P, Biswas D, Yu Y, Stewart JM, Stillman DJ. TATA-binding protein mutants that are lethal in the absence of the Nhp6 high-mobility-group protein. Mol Cell Biol 2004; 24:6419-29. [PMID: 15226442 PMCID: PMC434259 DOI: 10.1128/mcb.24.14.6419-6429.2004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Saccharomyces cerevisiae Nhp6 protein is related to the high-mobility-group B family of architectural DNA-binding proteins that bind DNA nonspecifically but bend DNA sharply. Nhp6 is involved in transcriptional activation by both RNA polymerase II (Pol II) and Pol III. Our previous genetic studies have implicated Nhp6 in facilitating TATA-binding protein (TBP) binding to some Pol II promoters in vivo, and we have used a novel genetic screen to isolate 32 new mutations in TBP that are viable in wild-type cells but lethal in the absence of Nhp6. The TBP mutations that are lethal in the absence of Nhp6 cluster in three regions: on the upper surface of TBP that may have a regulatory role, near residues that contact Spt3, or near residues known to contact either TFIIA or Brf1 (in TFIIIB). The latter set of mutations suggests that Nhp6 becomes essential when a TBP mutant compromises its ability to interact with either TFIIA or Brf1. Importantly, the synthetic lethality for some of the TBP mutations is suppressed by a multicopy plasmid with SNR6 or by an spt3 mutation. It has been previously shown that nhp6ab mutants are defective in expressing SNR6, a Pol III-transcribed gene encoding the U6 splicing RNA. Chromatin immunoprecipitation experiments show that TBP binding to SNR6 is reduced in an nhp6ab mutant. Nhp6 interacts with Spt16/Pob3, the yeast equivalent of the FACT elongation complex, consistent with nhp6ab cells being extremely sensitive to 6-azauracil (6-AU). However, this 6-AU sensitivity can be suppressed by multicopy SNR6 or BRF1. Additionally, strains with SNR6 promoter mutations are sensitive to 6-AU, suggesting that decreased SNR6 RNA levels contribute to 6-AU sensitivity. These results challenge the widely held belief that 6-AU sensitivity results from a defect in transcriptional elongation.
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Affiliation(s)
- Peter Eriksson
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA
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38
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Warfield L, Ranish JA, Hahn S. Positive and negative functions of the SAGA complex mediated through interaction of Spt8 with TBP and the N-terminal domain of TFIIA. Genes Dev 2004; 18:1022-34. [PMID: 15132995 PMCID: PMC406292 DOI: 10.1101/gad.1192204] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A surface that is required for rapid formation of preinitiation complexes (PICs) was identified on the N-terminal domain (NTD) of the RNA Pol II general transcription factor TFIIA. Site-specific photocross-linkers and tethered protein cleavage reagents positioned on the NTD of TFIIA and assembled in PICs identified the SAGA subunit Spt8 and the TFIID subunit Taf4 as located near this surface. In agreement with these findings, mutations in Spt8 and the TFIIA NTD interact genetically. Using purified proteins, it was found that TFIIA and Spt8 do not stably bind to each other, but rather both compete for binding to TBP. Consistent with this competition, Spt8 inhibits the binding of SAGA to PICs in the absence of activator. In the presence of activator, Spt8 enhances transcription in vitro, and the positive function of the TFIIA NTD is largely mediated through Spt8. Our results suggest a mechanism for the previously observed positive and negative effects of Spt8 on transcription observed in vivo.
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Affiliation(s)
- Linda Warfield
- Fred Hutchinson Cancer Research Center, and Howard Hughes Medical Institute, Seattle, WA 98109, USA
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39
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Cheng H, He X, Moore C. The essential WD repeat protein Swd2 has dual functions in RNA polymerase II transcription termination and lysine 4 methylation of histone H3. Mol Cell Biol 2004; 24:2932-43. [PMID: 15024081 PMCID: PMC371121 DOI: 10.1128/mcb.24.7.2932-2943.2004] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Swd2, an essential WD repeat protein in Saccharomyces cerevisiae, is a component of two very different complexes: the cleavage and polyadenylation factor CPF and the Set1 methylase, which modifies lysine 4 of histone H3 (H3-K4). It was not known if Swd2 is important for the function of either of these entities. We show here that, in extract from cells depleted of Swd2, cleavage and polyadenylation of the mRNA precursor in vitro are completely normal. However, temperature-sensitive mutations or depletion of Swd2 causes termination defects in some genes transcribed by RNA polymerase II. Overexpression of Ref2, a protein previously implicated in snoRNA 3' end formation and Swd2 recruitment to CPF, can rescue the growth and termination defects, indicating a functional interaction between the two proteins. Some swd2 mutations also significantly decrease global H3-K4 methylation and cause other phenotypes associated with loss of this chromatin modification, such as loss of telomere silencing, hydroxyurea sensitivity, and alterations in repression of INO1 transcription. Even though the two Swd2-containing complexes are both localized to actively transcribed genes, the allele specificities of swd2 defects suggest that the functions of Swd2 in mediating RNA polymerase II termination and H3-K4 methylation are not tightly coupled.
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Affiliation(s)
- Hailing Cheng
- Tufts University School of Medicine and Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts 02111, USA
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40
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Geisberg JV, Struhl K. Cellular Stress Alters the Transcriptional Properties of Promoter-Bound Mot1-TBP Complexes. Mol Cell 2004; 14:479-89. [PMID: 15149597 DOI: 10.1016/j.molcel.2004.05.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2003] [Revised: 03/16/2004] [Accepted: 03/30/2004] [Indexed: 11/28/2022]
Abstract
Mot1 associates with transcriptionally active promoters, and it directly affects transcriptional activity in a positive or negative manner, depending on the gene. As determined by sequential chromatin immunoprecipitation, Mot1 co-occupies promoters with TBP, but not with TFIIB, TFIIA, or Pol II when cells are grown in normal conditions. This strongly suggests that the Mot1-TBP complex is transcriptionally inactive, and hence is in dynamic equilibrium with transcriptionally active forms of TBP. Surprisingly, in response to heat shock and other forms of environmental stress, Mot1 co-occupies promoters with TFIIB and elongation-competent Pol II, but not with TFIIA. This suggests that functional preinitiation complexes can contain Mot1 instead of TFIIA in vivo. Thus, Mot1-TBP complexes can exist in active and inactive forms that are regulated by environmental stress.
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Affiliation(s)
- Joseph V Geisberg
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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41
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Topalidou I, Papamichos-Chronakis M, Thireos G, Tzamarias D. Spt3 and Mot1 cooperate in nucleosome remodeling independently of TBP recruitment. EMBO J 2004; 23:1943-8. [PMID: 15057269 PMCID: PMC404319 DOI: 10.1038/sj.emboj.7600199] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2003] [Accepted: 03/11/2004] [Indexed: 11/08/2022] Open
Abstract
We have investigated the requirements for nucleosome remodeling upon transcriptional induction of the GAL1 promoter. We found that remodeling was dependent on two SAGA complex components, Gcn5 and Spt3. The involvement of the latter was surprising as its function has been suggested to be directly involved in TATA-binding protein (TBP) recruitment. We demonstrated that this novel function was in fact independent of TBP recruitment and this was further validated using a Gal4-driven synthetic promoter. Most importantly, we showed that the involvement of Spt3 in chromatin remodeling was independent of transcription, as it was also observed for a nonpromoter nucleosome located next to an activator-binding site. In an effort to explore how the Spt3 function was elicited, we found that Mot1, an ATPase of the Snf2 family that genetically interacts with Spt3, was also required for nucleosome remodeling independently of TBP recruitment. Interestingly enough, Spt3 and Mot1 were recruited on the GAL1 promoter as well as on the nonpromoter site in an interdependent manner. These findings show that the two proteins cooperate in nucleosomal transactions.
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Affiliation(s)
- Irini Topalidou
- Institute of Molecular Biology and Biotechnology, FORTH, Crete, Greece
| | | | - George Thireos
- Institute of Molecular Biology and Biotechnology, FORTH, Crete, Greece
- Institute of Molecular Biology and Biotechnology, FORTH, PO Box 1527, 71110 Heraklion, Crete, Greece. Tel: +30 2 810 391109; Fax: +30 2 810 391101; E-mail:
| | - Dimitris Tzamarias
- Institute of Molecular Biology and Biotechnology, FORTH, Crete, Greece
- School of Science & Technology, Hellenic Open University, Patras, Greece
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42
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Pereira LA, Klejman MP, Timmers HTM. Roles for BTAF1 and Mot1p in dynamics of TATA-binding protein and regulation of RNA polymerase II transcription. Gene 2003; 315:1-13. [PMID: 14557059 DOI: 10.1016/s0378-1119(03)00714-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Regulation of RNA polymerase II (pol II) transcription is a highly dynamic process requiring the coordinated interaction of an array of regulatory proteins. Central to this process is the TATA-binding protein (TBP), the key component of the multiprotein complex TFIID. Interaction of TBP with core promoters nucleates the assembly of the preinitiation complex and subsequent recruitment of pol II. Despite recent advances in our understanding of the dynamic nature of the pol II transcription apparatus, the dynamics of TBP function on pol II promoters has remained largely unexplored. Human BTAF1 (TAF(II)170/TAF-172) and its yeast ortholog, Mot1p, are evolutionarily conserved members of the SNF2-like family of ATPase proteins. Genetic identification of Mot1p as a repressor of pol II transcription was supported by findings that Mot1p and BTAF1 could dissociate TBP from TATA DNA complexes using the energy of ATP hydrolysis. Recent data have revealed new aspects of BTAF1 and Mot1p as positive regulators of TBP function in the pol II system and have described new observations relating to their molecular mechanism of action. We review these data in the context of previous findings with particular attention paid to how human BTAF1 and Mot1p may dynamically regulate TBP function on pol II promoters in cells.
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Affiliation(s)
- Lloyd A Pereira
- Laboratory for Physiological Chemistry, Division of Biomedical Genetics, UMC-U, Universiteitsweg 100, 3584 Utrecht CG, The Netherlands
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43
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Mitsiou DJ, Stunnenberg HG. p300 is involved in formation of the TBP-TFIIA-containing basal transcription complex, TAC. EMBO J 2003; 22:4501-11. [PMID: 12941701 PMCID: PMC202362 DOI: 10.1093/emboj/cdg419] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have recently identified a novel basal transcription complex, TAC, that is present and active in embryonal carcinoma (EC) cells but not in other adult cells such as COS7. In the search for factors involved in TAC formation, we found that expression of the adenoviral 12S E1A oncoprotein abolishes TAC formation in EC cells. This effect of E1A depends on its N-terminal domain that is essential for cell differentiation and that targets the transcriptional coactivators p300 and PCAF. Expression of p300 lacking its major E1A interaction domain, CH3, restores TAC formation in the presence of E1A, in a bromodomain- and HAT domain-dependent manner. Consistently, the unprocessed TFIIAalphabeta precursor that is selectively assembled into TAC is acetylated preferentially compared with the processed subunits present in 'free' TFIIA. Intriguingly, expression of p300 in COS7 cells that do not contain detectable levels of TAC instigates formation of TAC from endogenous components. Our data suggest that p300 plays a role in formation of the TBP-TFIIA-containing basal transcription complex, TAC.
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Affiliation(s)
- Dimitra J Mitsiou
- Department of Molecular Biology, University of Nijmegen, NCMLS 191, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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44
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Dasgupta A, Scovell WM. TFIIA abrogates the effects of inhibition by HMGB1 but not E1A during the early stages of assembly of the transcriptional preinitiation complex. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1627:101-10. [PMID: 12818428 DOI: 10.1016/s0167-4781(03)00080-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Successful assembly of the transcriptional preinitiation complex (PIC) is prerequisite to transcriptional initiation. At each stage of PIC assembly, regulation may occur as repressors and activators compete with and influence the incorporation of general transcription factors (GTFs). Both TFIIA and HMGB1 bind individually to the TATA-binding protein (TBP) to increase the rate of binding and to stabilize TBP binding to the TATA element. The competitive binding between these two cofactors for TBP/TATA was examined to show that TFIIA binds preferentially to TBP and inhibits HMGB1 binding. TFIIA can also readily dissociate HMGB1 from the preestablished HMGB1/TBP/TATA complex. This suggests that TFIIA and HMGB1 may bind to the same or overlapping sites on TBP and/or compete for similar DNA sites that are 5' to the TATA element. In addition, EMSA studies show that adenovirus E1A(13S) oncoprotein is unable to disrupt either the preestablished TFIIA/TBP/TATA or TFIIA/TFIIB/TBP/TATA complexes, but does inhibit complex formation when all transcription factors were simultaneously added. The inhibitory effect of E1A(13S) on the assembly of the PIC is overcome when excess TBP is added back in the reaction, while addition of either excess TFIIA or TFIIB were ineffective. This shows that the main target for E1A(13S) is free TBP and emphasizes the primary competition between E1A and the TATA-element for unbound TBP. This may be the principal point, if not the only point, at which E1A can target TBP to exert its inhibitory effect. This work, coupled with previous findings in our laboratory, indicates that TFIIA is much more effective than TFIIB in reversing the inhibitory effect of HMGB1 binding in the early stages of PIC assembly, which is consistent with the in vitro transcription results.
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Affiliation(s)
- A Dasgupta
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0213, USA
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45
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Gumbs OH, Campbell AM, Weil PA. High-affinity DNA binding by a Mot1p-TBP complex: implications for TAF-independent transcription. EMBO J 2003; 22:3131-41. [PMID: 12805227 PMCID: PMC162156 DOI: 10.1093/emboj/cdg304] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Yeast Mot1p, an abundant conserved member of the Snf2p-ATPase family of proteins, both dissociates TBP from DNA in vitro using the energy of ATP and represses gene transcription in vivo, yet paradoxically, loss of Mot1p function also leads to decreased transcription of certain genes. We conducted experiments utilizing fluorescently labeled DNA, TBP, fluorescence anisotropy spectroscopy and native gel electrophoresis to study Mot1p action. We have made a number of observations, the most intriguing being that a stable Mot1p-TBP complex has the ability to bind TATA DNA with high affinity, albeit with dramatically altered specificity. We propose that this altered TBP-DNA recognition is integral to Mot1p's ability to regulate transcription, and further postulate that the Mot1p-TBP complex delivers TBP to TAF-independent mRNA encoding genes.
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Affiliation(s)
- Orlando H Gumbs
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, TN 37232-0615, USA
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46
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He X, Khan AU, Cheng H, Pappas DL, Hampsey M, Moore CL. Functional interactions between the transcription and mRNA 3' end processing machineries mediated by Ssu72 and Sub1. Genes Dev 2003; 17:1030-42. [PMID: 12704082 PMCID: PMC196040 DOI: 10.1101/gad.1075203] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Transcription and processing of pre-mRNA are coupled events. By using a combination of biochemical, molecular, and genetic methods, we have found that the phylogenetically conserved transcription factor Ssu72 is a component of the cleavage/polyadenylation factor (CPF) of Saccharomyces cerevisiae. Our results demonstrate that Ssu72 is required for 3' end cleavage of pre-mRNA but is dispensable for poly(A) addition and RNAP II termination. The in vitro cleavage defect caused by depletion of Ssu72 from cells can be rescued by addition of recombinant Ssu72. Ssu72 interacts physically and genetically with the Pta1 subunit of CPF. Overexpression of PTA1 causes synthetic lethality in an ssu72-3 mutant. Moreover, Sub1, which has been implicated in transcription initiation and termination, also interacts with Pta1, and overexpression of SUB1 suppresses the growth and processing defect of a pta1 mutation. Physical interactions of Ssu72 and Sub1 with Pta1 are mutually exclusive. Based on the interactions of Ssu72 and Sub1 with both the Pta1 of CPF and the TFIIB component of the initiation complex, we present a model describing how these novel connections between the transcription and 3' end processing machineries might facilitate transitions in the RNAP II transcription cycle.
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Affiliation(s)
- Xiaoyuan He
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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47
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Swanson MJ, Qiu H, Sumibcay L, Krueger A, Kim SJ, Natarajan K, Yoon S, Hinnebusch AG. A multiplicity of coactivators is required by Gcn4p at individual promoters in vivo. Mol Cell Biol 2003; 23:2800-20. [PMID: 12665580 PMCID: PMC152555 DOI: 10.1128/mcb.23.8.2800-2820.2003] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2002] [Revised: 10/22/2002] [Accepted: 01/15/2003] [Indexed: 11/20/2022] Open
Abstract
Transcriptional activators interact with multisubunit coactivators that modify chromatin structure or recruit the general transcriptional machinery to their target genes. Budding yeast cells respond to amino acid starvation by inducing an activator of amino acid biosynthetic genes, Gcn4p. We conducted a comprehensive analysis of viable mutants affecting known coactivator subunits from the Saccharomyces Genome Deletion Project for defects in activation by Gcn4p in vivo. The results confirm previous findings that Gcn4p requires SAGA, SWI/SNF, and SRB mediator (SRB/MED) and identify key nonessential subunits of these complexes required for activation. Among the numerous histone acetyltransferases examined, only that present in SAGA, Gcn5p, was required by Gcn4p. We also uncovered a dependence on CCR4-NOT, RSC, and the Paf1 complex. In vitro binding experiments suggest that the Gcn4p activation domain interacts specifically with CCR4-NOT and RSC in addition to SAGA, SWI/SNF, and SRB/MED. Chromatin immunoprecipitation experiments show that Mbf1p, SAGA, SWI/SNF, SRB/MED, RSC, CCR4-NOT, and the Paf1 complex all are recruited by Gcn4p to one of its target genes (ARG1) in vivo. We observed considerable differences in coactivator requirements among several Gcn4p-dependent promoters; thus, only a subset of the array of coactivators that can be recruited by Gcn4p is required at a given target gene in vivo.
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Affiliation(s)
- Mark J Swanson
- Laboratory of Gene Regulation and Development, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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48
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Abstract
NC2 is a heterodimeric regulator of transcription that plays both positive and negative roles in vivo. Here we show that the alpha and beta subunits of yeast NC2 are not always associated in a tight complex. Rather, their association is regulated, in particular by glucose depletion. Indeed, stable NC2 alpha/beta complexes can only be purified from cells after the diauxic shift when glucose has been depleted from the growth medium. In vivo, the presence of NC2 alpha, but not NC2 beta, at promoters generally correlates with the presence of TBP and transcriptional activity. In contrast, increased presence of NC2 beta relative to TBP correlates with transcriptional repression. NC2 is regulated by phosphorylation. We found that mutation of genes encoding casein kinase II (CKII) subunits as well as potential CKII phosphorylation sites in NC2 alpha and beta affected gene repression. Interestingly, NC2-dependent repression in the phosphorylation site mutants was only perturbed in high glucose when NC2 beta and NC2 alpha are not associated, but not after the diauxic shift when NC2 alpha and beta form stable complexes. Thus, the separation of NC2 alpha and beta function indicated by these mutants also supports the existence of multiple NC2 complexes with different functions in transcription.
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49
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Geisberg JV, Moqtaderi Z, Kuras L, Struhl K. Mot1 associates with transcriptionally active promoters and inhibits association of NC2 in Saccharomyces cerevisiae. Mol Cell Biol 2002; 22:8122-34. [PMID: 12417716 PMCID: PMC134071 DOI: 10.1128/mcb.22.23.8122-8134.2002] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mot1 stably associates with the TATA-binding protein (TBP), and it can dissociate TBP from DNA in an ATP-dependent manner. Mot1 acts as a negative regulator of TBP function in vitro, but genome-wide transcriptional profiling suggests that Mot1 positively affects about 10% of yeast genes and negatively affects about 5%. Unexpectedly, Mot1 associates with active RNA polymerase (Pol) II and III promoters, and it is rapidly recruited in response to activator proteins. At Pol II promoters, Mot1 association requires TBP and is strongly correlated with the level of TBP occupancy. However, the Mot1/TBP occupancy ratio at both Mot1-stimulated and Mot1-inhibited promoters is high relative to that at typical promoters, strongly suggesting that Mot1 directly affects transcriptional activity in a positive or negative manner, depending on the gene. The effect of Mot1 at the HIS3 promoter region depends on the functional quality and DNA sequence of the TATA element. Unlike TBP, Mot1 association is largely independent of the Srb4 component of Pol II holoenzyme, and it also can occur downstream of the promoter region. Mot1 removes TBP, but not TBP complexes or preinitiation complexes, from inappropriate genomic locations. Mot1 inhibits the association of NC2 with promoters, suggesting that the TBP-Mot1 and TBP-NC2 complexes compete for promoter occupancy in vivo. We speculate that Mot1 does not form transcriptionally active TBP complexes but rather regulates transcription in vivo by modulating the activity of free TBP and/or by affecting promoter DNA structure.
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Affiliation(s)
- Joseph V Geisberg
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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50
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Andrau JC, Van Oevelen CJ, Van Teeffelen HA, Weil P, Holstege FC, Timmers H. Mot1p is essential for TBP recruitment to selected promoters during in vivo gene activation. EMBO J 2002; 21:5173-83. [PMID: 12356733 PMCID: PMC129025 DOI: 10.1093/emboj/cdf485] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recruitment of TATA-binding protein (TBP) is central to activation of transcription by RNA polymerase II (pol II). This depends upon co-activator proteins including TBP-associated factors (TAFs). Yeast Mot1p was identified as a general transcriptional repressor in genetic screens and is also found associated with TBP. To obtain insight into Mot1p function in vivo, we determined the mRNA expression profile of the mot1-1 temperature-sensitive (Ts) strain. Unexpectedly, this indicated that Mot1p mostly plays a positive role for transcription. For one potential activation target, HXT2, we analyzed promoter recruitment of Mot1p, TBP, Taf1p (Taf130p) and pol II by chromatin immunoprecipitation assays. Whereas TBP becomes stably associated upon activation of the HXT2 and HXT4 promoters, Mot1p showed only a transient association. TBP recruitment was compromised in two different mot1 mutant strains, but was only moderately affected in a taf1 Ts strain. Together, our data indicate that Mot1p can assist in recruitment of TBP on promoters during gene activation in vivo.
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Affiliation(s)
- Jean-Christophe Andrau
- Laboratory for Physiological Chemistry and Department of Medical Genetics, UMC Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232 and Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA Corresponding author e-mail:
| | - Chris J.C. Van Oevelen
- Laboratory for Physiological Chemistry and Department of Medical Genetics, UMC Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232 and Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA Corresponding author e-mail:
| | - Hetty A.A.M. Van Teeffelen
- Laboratory for Physiological Chemistry and Department of Medical Genetics, UMC Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232 and Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA Corresponding author e-mail:
| | - P.Anthony Weil
- Laboratory for Physiological Chemistry and Department of Medical Genetics, UMC Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232 and Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA Corresponding author e-mail:
| | - Frank C.P. Holstege
- Laboratory for Physiological Chemistry and Department of Medical Genetics, UMC Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232 and Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA Corresponding author e-mail:
| | - H.Th.Marc Timmers
- Laboratory for Physiological Chemistry and Department of Medical Genetics, UMC Utrecht, PO Box 85060, 3508 AB Utrecht, The Netherlands, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232 and Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA Corresponding author e-mail:
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