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Avendaño-Borromeo B, Narayanasamy RK, García-Rivera G, Labra-Barrios ML, Lagunes-Guillén AE, Munguía-Chávez B, Castañón-Sánchez CA, Orozco E, Luna-Arias JP. Identification of the gene encoding the TATA box-binding protein-associated factor 1 (TAF1) and its putative role in the heat shock response in the protozoan parasite Entamoeba histolytica. Parasitol Res 2018; 118:517-538. [PMID: 30552577 DOI: 10.1007/s00436-018-6170-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 11/29/2018] [Indexed: 11/26/2022]
Abstract
Transcription factor IID (TFIID) is a cornerstone in the transcription initiation in eukaryotes. It is composed of TBP and approximately 14 different subunits named TBP-associated factors (TAFs). TFIID has a key role in transcription of many genes involved in cell proliferation, cell growth, cell cycle, cell cycle checkpoint, and various other processes as well. Entamoeba histolytica, the protozoan parasite responsible for human amoebiasis, represents a major global health concern. Our research group has previously reported the genes coding the TATA box-binding protein (EhTBP) and TBP-related factor 1 (EhTRF1), which displayed different mRNA levels in trophozoites under different stress conditions. In this work, we identified the TBP-associated factor 1 (Ehtaf1) gene in the E. histolytica genome, which possess a well-conserved DUF domain and a Bromo domain located in the middle and C-terminus of the protein, respectively. The EhTAF1-DUF domain tertiary structure is similar to the corresponding HsTAF1 DUF domain. RT-qPCR experiments with RNA isolated from trophozoites harvested at different time points of the growth curve and under different stress conditions revealed that the Ehtaf1 gene was found slightly upregulated in the death phase of growth curve, but under heat shock stress, it was found upregulated 10 times, suggesting that Ehtaf1 might have an important role in the heat shock stress response. We also found that EhTAF1 is expressed in the nucleus and cytoplasm at 37 °C, but under heat shock stress, it is overexpressed in both the nucleus and cytoplasm, and partially colocalized with EhHSP70 in cytoplasm.
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Affiliation(s)
- Bartolo Avendaño-Borromeo
- Departamento de Biología Celular, Cinvestav-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Ravi Kumar Narayanasamy
- Departamento de Biología Celular, Cinvestav-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Guillermina García-Rivera
- Departamento de Infectómica y Patogénesis Molecular, Cinvestav-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - María Luisa Labra-Barrios
- Departamento de Biología Celular, Cinvestav-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Anel E Lagunes-Guillén
- Departamento de Infectómica y Patogénesis Molecular, Cinvestav-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Bibiana Munguía-Chávez
- Departamento de Infectómica y Patogénesis Molecular, Cinvestav-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Carlos Alberto Castañón-Sánchez
- Laboratorio de Investigación Biomédica, Subdirección de Enseñanza e Investigación, Hospital Regional de Alta Especialidad de Oaxaca, Aldama S/N, San Bartolo Coyotepec, 71256, Oaxaca, Mexico
| | - Esther Orozco
- Departamento de Infectómica y Patogénesis Molecular, Cinvestav-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Juan Pedro Luna-Arias
- Departamento de Biología Celular, Cinvestav-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico.
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2
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Bae NS, Seberg AP, Carroll LP, Swanson MJ. Identification of Genes in Saccharomyces cerevisiae that Are Haploinsufficient for Overcoming Amino Acid Starvation. G3 (BETHESDA, MD.) 2017; 7:1061-1084. [PMID: 28209762 PMCID: PMC5386856 DOI: 10.1534/g3.116.037416] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/11/2017] [Indexed: 12/17/2022]
Abstract
The yeast Saccharomyces cerevisiae responds to amino acid deprivation by activating a pathway conserved in eukaryotes to overcome the starvation stress. We have screened the entire yeast heterozygous deletion collection to identify strains haploinsufficient for growth in the presence of sulfometuron methyl, which causes starvation for isoleucine and valine. We have discovered that cells devoid of MET15 are sensitive to sulfometuron methyl, and loss of heterozygosity at the MET15 locus can complicate screening the heterozygous deletion collection. We identified 138 cases of loss of heterozygosity in this screen. After eliminating the issues of the MET15 loss of heterozygosity, strains isolated from the collection were retested on sulfometuron methyl. To determine the general effect of the mutations for a starvation response, SMM-sensitive strains were tested for the ability to grow in the presence of canavanine, which induces arginine starvation, and strains that were MET15 were also tested for growth in the presence of ethionine, which causes methionine starvation. Many of the genes identified in our study were not previously identified as starvation-responsive genes, including a number of essential genes that are not easily screened in a systematic way. The genes identified span a broad range of biological functions, including many involved in some level of gene expression. Several unnamed proteins have also been identified, giving a clue as to possible functions of the encoded proteins.
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Affiliation(s)
- Nancy S Bae
- Department of Biochemistry, Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona 85308
| | - Andrew P Seberg
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4295
| | - Leslie P Carroll
- Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, Georgia 31207
| | - Mark J Swanson
- Department of Biochemistry, Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona 85308
- Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, Georgia 31207
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3
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Feigerle JT, Weil PA. The C Terminus of the RNA Polymerase II Transcription Factor IID (TFIID) Subunit Taf2 Mediates Stable Association of Subunit Taf14 into the Yeast TFIID Complex. J Biol Chem 2016; 291:22721-22740. [PMID: 27587401 DOI: 10.1074/jbc.m116.751107] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 08/31/2016] [Indexed: 12/22/2022] Open
Abstract
The evolutionarily conserved RNA polymerase II transcription factor D (TFIID) complex is composed of TATA box-binding protein (TBP) and 13 TBP-associated factors (Tafs). The mechanisms by which many Taf subunits contribute to the essential function of TFIID are only poorly understood. To address this gap in knowledge, we present the results of a molecular genetic dissection of the TFIID subunit Taf2. Through systematic site-directed mutagenesis, we have discovered 12 taf2 temperature-sensitive (ts) alleles. Two of these alleles display growth defects that can be strongly suppressed by overexpression of the yeast-specific TFIID subunit TAF14 but not by overexpression of any other TFIID subunit. In Saccharomyces cerevisiae, Taf14 is also a constituent of six other transcription-related complexes, making interpretation of its role in each of these complexes difficult. Although Taf14 is not conserved as a TFIID subunit in metazoans, it is conserved through its chromatin-binding YEATS domain. Based on the Taf2-Taf14 genetic interaction, we demonstrate that Taf2 and Taf14 directly interact and mapped the Taf2-Taf14 interaction domains. We used this information to identify a Taf2 separation-of-function variant (Taf2-ΔC). Although Taf2-ΔC no longer interacts with Taf14 in vivo or in vitro, it stably incorporates into the TFIID complex. In addition, purified Taf2-ΔC mutant TFIID is devoid of Taf14, making this variant a powerful reagent for determining the role of Taf14 in TFIID function. Furthermore, we characterized the mechanism through which Taf14 suppresses taf2ts alleles, shedding light on how Taf2-Taf14 interaction contributes to TFIID complex organization and identifying a potential role for Taf14 in mediating TFIID-chromatin interactions.
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Affiliation(s)
- Jordan T Feigerle
- From the Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615
| | - P Anthony Weil
- From the Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615
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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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Kruk JA, Dutta A, Fu J, Gilmour DS, Reese JC. The multifunctional Ccr4-Not complex directly promotes transcription elongation. Genes Dev 2011; 25:581-93. [PMID: 21406554 DOI: 10.1101/gad.2020911] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The Ccr4-Not complex has been implicated in the control of multiple steps of mRNA metabolism; however, its functions in transcription remain ambiguous. The discovery that Ccr4/Pop2 is the major cytoplasmic mRNA deadenylase and the detection of Not proteins within mRNA processing bodies have raised questions about the roles of the Ccr4-Not complex in transcription. Here we firmly establish Ccr4-Not as a positive elongation factor for RNA polymerase II (RNAPII). The Ccr4-Not complex is targeted to the coding region of genes in a transcription-dependent manner similar to RNAPII and promotes elongation in vivo. Furthermore, Ccr4-Not interacts directly with elongating RNAPII complexes and stimulates transcription elongation of arrested polymerase in vitro. Ccr4-Not can reactivate backtracked RNAPII using a mechanism different from that of the well-characterized elongation factor TFIIS. While not essential for its interaction with elongation complexes, Ccr4-Not interacts with the emerging transcript and promotes elongation in a manner dependent on transcript length, although this interaction is not required for it to bind RNAPII. Our comprehensive analysis shows that Ccr4-Not directly regulates transcription, and suggests it does so by promoting the resumption of elongation of arrested RNAPII when it encounters transcriptional blocks in vivo.
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Affiliation(s)
- Jennifer A Kruk
- Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Bhaumik SR. Distinct regulatory mechanisms of eukaryotic transcriptional activation by SAGA and TFIID. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1809:97-108. [PMID: 20800707 DOI: 10.1016/j.bbagrm.2010.08.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 08/18/2010] [Accepted: 08/19/2010] [Indexed: 01/08/2023]
Abstract
A growing number of human diseases are linked to abnormal gene expression which is largely controlled at the level of transcriptional initiation. The gene-specific activator promotes the initiation of transcription through its interaction with one or more components of the transcriptional initiation machinery, hence leading to stimulated transcriptional initiation or activation. However, all activator proteins do not target the same component(s) of the transcriptional initiation machinery. Rather, they can have different target specificities, and thus, can lead to distinct mechanisms of transcriptional activation. Two such distinct mechanisms of transcriptional activation in yeast are mediated by the SAGA (Spt-Ada-Gcn5-Acetyltransferase) and TFIID (Transcription factor IID) complexes, and are termed as "SAGA-dependent" and "TFIID-dependent" transcriptional activation, respectively. SAGA is the target of the activator in case of SAGA-dependent transcriptional activation, while the targeting of TFIID by the activator leads to TFIID-dependent transcriptional activation. Both the SAGA and TFIID complexes are highly conserved from yeast to human, and play crucial roles in gene activation among eukaryotes. The regulatory mechanisms of eukaryotic transcriptional activation by SAGA and TFIID are discussed here. This article is part of a Special Issue entitled The 26S Proteasome: When degradation is just not enough!
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Affiliation(s)
- Sukesh R Bhaumik
- Department of Biochemistry and Molecular Biology, Southern Illnois University School of Medicine, Carbondale, IL 62901, USA.
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Abstract
Regulation of eukaryotic gene expression is far more complex than one might have imagined 30 years ago. However, progress towards understanding gene regulatory mechanisms has been rapid and comprehensive, which has made the integration of detailed observations into broadly connected concepts a challenge. This review attempts to integrate the following concepts: (1) a well-defined organization of nucleosomes and modification states at most genes; (2) regulatory networks of sequence-specific transcription factors; (3) chromatin remodeling coupled to promoter assembly of the general transcription factors and RNA polymerase II; and (4) phosphorylation states of RNA polymerase II coupled to chromatin modification states during transcription. The wealth of new insights arising from the tools of biochemistry, genomics, cell biology, and genetics is providing a remarkable view into the mechanics of gene regulation.
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Affiliation(s)
- Bryan J Venters
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
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Cler E, Papai G, Schultz P, Davidson I. Recent advances in understanding the structure and function of general transcription factor TFIID. Cell Mol Life Sci 2009; 66:2123-34. [PMID: 19308322 PMCID: PMC11115924 DOI: 10.1007/s00018-009-0009-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 02/19/2009] [Accepted: 02/23/2009] [Indexed: 01/18/2023]
Abstract
The general transcription factor TFIID is a macromolecular complex comprising the TATA-binding protein (TBP) and a set of 13-14 TBP associated factors (TAFs). This review discusses biochemical, genetic and electron microscopic data acquired over the past years that provide a model for the composition, organisation and assembly of TFIID. We also revisit ideas on how TFIID is recruited to the promoters of active and possibly repressed genes. Recent observations show that recognition of acetylated and methylated histone residues by structural domains in several TAFs plays an important role. Finally, we highlight several genetic studies suggesting that TFIID is required for initiation of transcription, but not for maintaining transcription once a promoter is in an active state.
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Affiliation(s)
- Emilie Cler
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 1 Rue Laurent Fries, 67404 Illkirch Cedex, France
| | - Gabor Papai
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 1 Rue Laurent Fries, 67404 Illkirch Cedex, France
| | - Patrick Schultz
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 1 Rue Laurent Fries, 67404 Illkirch Cedex, France
| | - Irwin Davidson
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 1 Rue Laurent Fries, 67404 Illkirch Cedex, France
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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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10
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Yeast Rap1 contributes to genomic integrity by activating DNA damage repair genes. EMBO J 2008; 27:1575-84. [PMID: 18480842 DOI: 10.1038/emboj.2008.93] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 04/14/2008] [Indexed: 11/08/2022] Open
Abstract
Rap1 (repressor-activator protein 1) is a multifunctional protein that controls telomere function, silencing and the activation of glycolytic and ribosomal protein genes. We have identified a novel function for Rap1, regulating the ribonucleotide reductase (RNR) genes that are required for DNA repair and telomere expansion. Both the C terminus and DNA-binding domain of Rap1 are required for the activation of the RNR genes, and the phenotypes of different Rap1 mutants suggest that it utilizes both regions to carry out distinct steps in the activation process. Recruitment of Rap1 to the RNR3 gene is dependent on activation of the DNA damage checkpoint and chromatin remodelling by SWI/SNF. The dependence on SWI/SNF for binding suggests that Rap1 acts after remodelling to prevent the repositioning of nucleosomes back to the repressed state. Furthermore, the recruitment of Rap1 requires TAF(II)s, suggesting a role for TFIID in stabilizing activator binding in vivo. We propose that Rap1 acts as a rheostat controlling nucleotide pools in response to shortened telomeres and DNA damage, providing a mechanism for fine-tuning the RNR genes during checkpoint activation.
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Romier C, James N, Birck C, Cavarelli J, Vivarès C, Collart MA, Moras D. Crystal structure, biochemical and genetic characterization of yeast and E. cuniculi TAF(II)5 N-terminal domain: implications for TFIID assembly. J Mol Biol 2007; 368:1292-306. [PMID: 17397863 DOI: 10.1016/j.jmb.2007.02.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Revised: 02/09/2007] [Accepted: 02/13/2007] [Indexed: 11/16/2022]
Abstract
General transcription factor TFIID plays an essential role in transcription initiation by RNA polymerase II at numerous promoters. However, understanding of the assembly and a full structural characterization of this large 15 subunit complex is lacking. TFIID subunit TAF(II)5 has been shown to be present twice in this complex and to be critical for the function and assembly of TFIID. Especially, the TAF(II)5 N-terminal domain is required for its incorporation within TFIID and immuno-labelling experiments carried out by electron microscopy at low resolution have suggested that this domain might homodimerize, possibly explaining the three-lobed architecture of TFIID. However, the resolution at which the electron microscopy (EM) analyses were conducted is not sufficient to determine whether homodimerization occurs or whether a more intricate assembly implying other subunits is required. Here we report the X-ray structures of the fully evolutionary conserved C-terminal sub-domain of the TAF(II)5 N terminus, from yeast and the mammalian parasite Encephalitozoon cuniculi. This sub-domain displays a novel fold with specific surfaces having conserved physico-chemical properties that can form protein-protein interactions. Although a crystallographic dimer implying one of these surfaces is present in one of the crystal forms, several biochemical analyses show that this sub-domain is monomeric in solution, even at various salt conditions and in presence of different divalent cations. Consequently, the N-terminal sub-domain of the TAF(II)5 N terminus, which is homologous to a dimerization motif but has not been fully conserved during evolution, was studied by analytical ultracentrifugation and yeast genetics. Our results show that this sub-domain dimerizes at very high concentration but is neither required for yeast viability, nor for incorporation of two TAF(II)5 molecules within TFIID and for the assembly of this complex. Altogether, although our results do not argue in favour of a homodimerization of the TAF(II)5 N-terminal domain, our structural analyses suggest a role for this domain in assembly of TFIID and its related complexes SAGA, STAGA, TFTC and PCAF.
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Affiliation(s)
- Christophe Romier
- Institut de Génétique et Biologie Moléculaire et Cellulaire (IGBMC), Département de Biologie et Génomique Structurales, 1 rue Laurent Fries, B.P. 10142, 67404 Illkirch Cedex, France
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12
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Abstract
In eukaryotes, the core promoter serves as a platform for the assembly of transcription preinitiation complex (PIC) that includes TFIIA, TFIIB, TFIID, TFIIE, TFIIF, TFIIH, and RNA polymerase II (pol II), which function collectively to specify the transcription start site. PIC formation usually begins with TFIID binding to the TATA box, initiator, and/or downstream promoter element (DPE) found in most core promoters, followed by the entry of other general transcription factors (GTFs) and pol II through either a sequential assembly or a preassembled pol II holoenzyme pathway. Formation of this promoter-bound complex is sufficient for a basal level of transcription. However, for activator-dependent (or regulated) transcription, general cofactors are often required to transmit regulatory signals between gene-specific activators and the general transcription machinery. Three classes of general cofactors, including TBP-associated factors (TAFs), Mediator, and upstream stimulatory activity (USA)-derived positive cofactors (PC1/PARP-1, PC2, PC3/DNA topoisomerase I, and PC4) and negative cofactor 1 (NC1/HMGB1), normally function independently or in combination to fine-tune the promoter activity in a gene-specific or cell-type-specific manner. In addition, other cofactors, such as TAF1, BTAF1, and negative cofactor 2 (NC2), can also modulate TBP or TFIID binding to the core promoter. In general, these cofactors are capable of repressing basal transcription when activators are absent and stimulating transcription in the presence of activators. Here we review the roles of these cofactors and GTFs, as well as TBP-related factors (TRFs), TAF-containing complexes (TFTC, SAGA, SLIK/SALSA, STAGA, and PRC1) and TAF variants, in pol II-mediated transcription, with emphasis on the events occurring after the chromatin has been remodeled but prior to the formation of the first phosphodiester bond.
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Affiliation(s)
- Mary C Thomas
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH 44106-4935, USA
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13
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Abstract
Transcription factor IID (TFIID) plays a central role in regulating the expression of most eukaryotic genes. Of the 14 TBP-associated factor (TAF) subunits that compose TFIID, TAF1 is one of the largest and most functionally diverse. Yeast TAF1 can be divided into four regions including a putative histone acetyltransferase domain and TBP, TAF, and promoter binding domains. Establishing the importance of each region in gene expression through deletion analysis has been hampered by the cellular requirement of TAF1 for viability. To circumvent this limitation we introduced galactose-inducible deletion derivatives of previously defined functional regions of TAF1 into a temperature-sensitive taf1ts2 yeast strain. After galactose induction of the TAF1 mutants and temperature-induced elimination of the resident Taf1ts2 protein, we examined the properties and phenotypes of the mutants, including their impact on genome-wide transcription. Virtually all TAF1-dependent genes, which comprise approximately 90% of the yeast genome, displayed a strong dependence upon all regions of TAF1 that were tested. This finding might reflect the need for each region of TAF1 to stabilize TAF1 against degradation or may indicate that all TAF1-dependent genes require the many activities of TAF1. Paradoxically, deletion of the region of TAF1 that is important for promoter binding interfered with the expression of many genes that are normally TFIID-independent/SAGA (Spt-Ada-Gcn5-acetyltransferase)-dominated, suggesting that this region normally prevents TAF1 (TFIID) from interfering with the expression of SAGA-regulated genes.
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Affiliation(s)
- Jordan D Irvin
- Department of Biochemistry and Molecular Biology, Center for Gene Regulation, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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14
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Zhang Z, Reese JC. Molecular genetic analysis of the yeast repressor Rfx1/Crt1 reveals a novel two-step regulatory mechanism. Mol Cell Biol 2005; 25:7399-411. [PMID: 16107689 PMCID: PMC1190298 DOI: 10.1128/mcb.25.17.7399-7411.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In Saccharomyces cerevisiae, the repressor Crt1 and the global corepressor Ssn6-Tup1 repress the DNA damage-inducible ribonucleotide reductase (RNR) genes. Initiation of DNA damage signals causes the release of Crt1 and Ssn6-Tup1 from the promoter, coactivator recruitment, and derepression of transcription, indicating that Crt1 plays a crucial role in the switch between gene repression and activation. Here we have mapped the functional domains of Crt1 and identified two independent repression domains and a region required for gene activation. The N terminus of Crt1 is the major repression domain, it directly binds to the Ssn6-Tup1 complex, and its repression activities are dependent upon Ssn6-Tup1 and histone deacetylases (HDACs). In addition, we identified a C-terminal repression domain, which is independent of Ssn6-Tup1 and HDACs and functions at native genes in vivo. Furthermore, we show that TFIID and SWI/SNF bind to a region within the N terminus of Crt1, overlapping with but distinct from the Ssn6-Tup1 binding and repression domain, suggesting that Crt1 may have activator functions. Crt1 mutants were constructed to dissect its activator and repressor functions. All of the mutants were competent for repression of the DNA damage-inducible genes, but a majority were "derepression-defective" mutants. Further characterization of these mutants indicated that they are capable of receiving DNA damage signals and releasing the Ssn6-Tup1 complex from the promoter but are selectively impaired for TFIID and SWI/SNF recruitment. These results imply a two-step activation model of the DNA damage-inducible genes and that Crt1 functions as a signal-dependent dual-transcription activator and repressor that acts in a transient manner.
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Affiliation(s)
- Zhengjian Zhang
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, 16802, USA
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15
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Carrillo E, Garrido E, Gariglio P. Specific in vitro interaction between papillomavirus E2 proteins and TBP-associated factors. Intervirology 2005; 47:342-9. [PMID: 15564746 DOI: 10.1159/000080878] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2003] [Accepted: 01/08/2004] [Indexed: 11/19/2022] Open
Abstract
The bovine and human papillomavirus (BPV/HPV) E2 proteins bind specifically to palindromic sequences ACCGN4CGGT that are concentrated within the viral long control region, where they regulate viral oncogene transcription. E2 can activate viral promoters over relatively large distances within the viral genome and was shown to cooperate with a number of cellular transcription factors. Transcriptional activator proteins, such as E2, are thought to act, at least in part, by influencing the assembly and/or stability of preinitiation complexes and it has been suggested that the transcription factor IID, composed by the TATA-binding protein (TBP) and numerous TBP-associated factors (TAFs), is a possible target of this important viral protein. In this paper, we demonstrate that E2 proteins associate in vitro with several TAFs, in particular with TAFII250 and TAFII80. In addition, we observed that the association of TAFII250 with BPV1 E2 is stronger than with HPV18 E2 and that the carboxy terminal domain of both viral proteins is involved in this interaction. On the other hand, TAFII80 binds with similar strength to both E2 proteins through their amino terminal region. These observations may help to explain the different behavior of bovine and human E2 proteins, since BPV E2 is a stronger transcriptional activator than HPV18 E2.
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Affiliation(s)
- Elba Carrillo
- Departamento de Genética y Biología Molecular, CINVESTAV-IPN, DF, México
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16
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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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17
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Sakurai H, Hashikawa N, Imazu H, Fukasawa T. Carboxy-terminal region of the yeast heat shock factor contains two domains that make transcription independent of the TFIIH protein kinase. Genes Cells 2004; 8:951-61. [PMID: 14750950 DOI: 10.1046/j.1356-9597.2003.00689.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Phosphorylation of the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II is implicated in transition from initiation to elongation in the transcription cycle. In yeast cells, Kin28, a subunit of the general transcription factor TFIIH, is responsible for the CTD phosphorylation. Although Kin28 is indispensable for transcription of many genes, its requirement is bypassed in certain genes such as SSA4 or CUP1, whose transcription is activated by the heat shock factor Hsf1. RESULTS We show that C-terminal region of Hsf1, which consists of an activation domain AR2 and a regulatory domain CTM, mediates the Kin28-independent transcription. The AR2 domain, when fused to the DNA-binding domain of Gal4 and recruited to the GAL7 gene via the Gal4-binding sequence, is sufficient for activating GAL7 in the absence of Kin28. We have further found that AR2 has an ability to recruit TATA box-binding protein-associated factors (TAFs) to the promoter. Consistently, transcription from promoters occupied naturally or artificially with TAFs is sustained in the absence of Kin28 function. CONCLUSIONS These results show that CTM modulates activation function of AR2 in the Hsf1 molecule. We also suggest that recruitment of TAFs to a promoter is involved in the Kin28-independent transcription.
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Affiliation(s)
- Hiroshi Sakurai
- School of Health Sciences, Faculty of Medicine, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
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18
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Singh MV, Bland CE, Weil PA. Molecular and genetic characterization of a Taf1p domain essential for yeast TFIID assembly. Mol Cell Biol 2004; 24:4929-42. [PMID: 15143185 PMCID: PMC416396 DOI: 10.1128/mcb.24.11.4929-4942.2004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Yeast Taf1p is an integral component of the multiprotein transcription factor TFIID. By using coimmunoprecipitation assays, coupled with a comprehensive set of deletion mutants encompassing the entire open reading frame of TAF1, we have discovered an essential role of a small portion of yeast Taf1p. This domain of Taf1p, termed region 4, consisting of amino acids 200 to 303, contributes critically to the assembly and stability of the 15-subunit TFIID holocomplex. Region 4 of Taf1p is mutationally sensitive, can assemble several Tafps into a partial TFIID complex, and interacts directly with Taf4p and Taf6p. Mutations in Taf1p-region 4 induce temperature-conditional growth of yeast cells. At the nonpermissive temperature these mutations have drastic effects on both TFIID integrity and mRNA synthesis. These data are consistent with the hypothesis that Taf1p subserves a critical scaffold function within the TFIID complex. The significance of these data with regard to TFIID structure and function is discussed.
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Affiliation(s)
- Madhu V Singh
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN 37232-0615, USA
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19
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Affiliation(s)
- Joseph C Reese
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, 203 Althouse Laboratory, University Park, Pennsylvania 16802, USA
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20
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Matangkasombut O, Auty R, Buratowski S. Structure and Function of the TFIID Complex. ADVANCES IN PROTEIN CHEMISTRY 2004; 67:67-92. [PMID: 14969724 DOI: 10.1016/s0065-3233(04)67003-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Oranart Matangkasombut
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA
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21
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Shen WC, Bhaumik SR, Causton HC, Simon I, Zhu X, Jennings EG, Wang TH, Young RA, Green MR. Systematic analysis of essential yeast TAFs in genome-wide transcription and preinitiation complex assembly. EMBO J 2003; 22:3395-402. [PMID: 12840001 PMCID: PMC165660 DOI: 10.1093/emboj/cdg336] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The general transcription factor TFIID is composed of the TATA box binding protein (TBP) and a set of conserved TBP-associated factors (TAFs). Here we report the completion of genome-wide expression profiling analyses of yeast strains bearing temperature-sensitive mutations in each of the 13 essential TAFs. The percentage of the yeast genome dependent on each TAF ranges from 3% (TAF2) to 59-61% (TAF9). Approximately 84% of yeast genes are dependent upon one or more TAFs and 16% of yeast genes are TAF independent. In addition, this complete analysis defines three distinct classes of yeast promoters whose transcriptional requirements for TAFs differ substantially. Using this collection of temperature-sensitive mutants, we show that in all cases the transcriptional dependence for a TAF can be explained by a requirement for TBP recruitment and assembly of the preinitiation complex (PIC). Unexpectedly, these assembly experiments reveal that TAF11 and TAF13 appear to provide the critical functional contacts with TBP during PIC assembly. Collectively, our results confirm and extend the proposal that individual TAFs have selective transcriptional roles and distinct functions.
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Affiliation(s)
- Wu-Cheng Shen
- Howard Hughes Medical Institute, Programs in Gene Function and Expression and Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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22
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Mishra AK, Vanathi P, Bhargava P. The transcriptional activator GAL4-VP16 regulates the intra-molecular interactions of the TATA-binding protein. J Biosci 2003; 28:423-36. [PMID: 12799489 DOI: 10.1007/bf02705117] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Binding characteristics of yeast TATA-binding protein (yTBP) over five oligomers having different TATA variants and lacking a UASGAL, showed that TATA-binding protein (TBP)-TATA complex gets stabilized in the presence of the acidic activator GAL4-VP16. Activator also greatly suppressed the non-specific TBP-DNA complex formation. The effects were more pronounced over weaker TATA boxes. Activator also reduced the TBP dimer levels both in vitro and in vivo, suggesting the dimer may be a direct target of transcriptional activators. The transcriptional activator facilitated the dimer to monomer transition and activated monomers further to help TBP bind even the weaker TATA boxes stably. The overall stimulatory effect of the GAL4-VP16 on the TBP-TATA complex formation resembles the known effects of removal of the N-terminus of TBP on its activity, suggesting that the activator directly targets the N-terminus of TBP and facilitates its binding to the TATA box.
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Affiliation(s)
- Anurag Kumar Mishra
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007,India
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23
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Kou H, Irvin JD, Huisinga KL, Mitra M, Pugh BF. Structural and functional analysis of mutations along the crystallographic dimer interface of the yeast TATA binding protein. Mol Cell Biol 2003; 23:3186-201. [PMID: 12697819 PMCID: PMC153203 DOI: 10.1128/mcb.23.9.3186-3201.2003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The TATA binding protein (TBP) is a central component of the eukaryotic transcription machinery and is subjected to both positive and negative regulation. As is evident from structural and functional studies, TBP's concave DNA binding surface is inhibited by a number of potential mechanisms, including homodimerization and binding to the TAND domain of the TFIID subunit TAF1 (yTAF(II)145/130). Here we further characterized these interactions by creating mutations at 24 amino acids within the Saccharomyces cerevisiae TBP crystallographic dimer interface. These mutants are impaired for dimerization, TAF1 TAND binding, and TATA binding to an extent that is consistent with the crystal or nuclear magnetic resonance structure of these or related interactions. In vivo, these mutants displayed a variety of phenotypes, the severity of which correlated with relative dimer instability in vitro. The phenotypes included a low steady-state level of the mutant TBP, transcriptional derepression, dominant slow growth (partial toxicity), and synthetic toxicity in combination with a deletion of the TAF1 TAND domain. These phenotypes cannot be accounted for by defective interactions with other known TBP inhibitors and likely reflect defects in TBP dimerization.
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Affiliation(s)
- Haiping Kou
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16803, USA
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24
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Deluen C, James N, Maillet L, Molinete M, Theiler G, Lemaire M, Paquet N, Collart MA. The Ccr4-not complex and yTAF1 (yTaf(II)130p/yTaf(II)145p) show physical and functional interactions. Mol Cell Biol 2002; 22:6735-49. [PMID: 12215531 PMCID: PMC134042 DOI: 10.1128/mcb.22.19.6735-6749.2002] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Saccharomyces cerevisiae Ccr4-Not complex is a global regulator of transcription that is thought to regulate TATA binding protein (TBP) function at certain promoters specifically. In this paper, we show interactions between the essential domain of Not1p, which interacts with Not4p and Not5p, and the N-terminal domain of yTAF1. We isolated a temperature-sensitive nonsense allele of TAF1, taf1-4, which is synthetically lethal at the permissive temperature when combined with not4 and not5 mutants and which produces high levels of a C-terminally truncated yTAF1 derivative. Overexpression of C-terminally truncated yTAF1 is toxic in not4 or not5 mutants, whereas overexpression of full-length yTAF1 suppresses not4. Furthermore, mutations in the autoinhibitory N-terminal TAND domain of yTAF1 suppress not5, and the overexpression of similar mutants does not suppress not4. We find that, like Not5p, yTAF1 acts as a repressor of stress response element-dependent transcription. Finally, we have evidence for stress-regulated occupancy of promoter DNA by Not5p and for Not5p-dependent regulation of yTAF1 association with promoter DNA. Taken together with our finding that Not1p copurifies with glutathione S-transferase-yTaf1 in large complexes, these results provide the first molecular evidence that the Ccr4-Not complex might interact with yTAF1 to regulate its association at promoters, a function that might in turn regulate the autoinhibitory N-terminal domain of yTAF1.
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Affiliation(s)
- Cécile Deluen
- Département de Biochimie Médicale, CMU, 1211 Geneva 4, Switzerland
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25
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Sanders SL, Garbett KA, Weil PA. Molecular characterization of Saccharomyces cerevisiae TFIID. Mol Cell Biol 2002; 22:6000-13. [PMID: 12138208 PMCID: PMC133964 DOI: 10.1128/mcb.22.16.6000-6013.2002] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2002] [Revised: 02/27/2002] [Accepted: 05/21/2002] [Indexed: 11/20/2022] Open
Abstract
We previously defined Saccharomyces cerevisiae TFIID as a 15-subunit complex comprised of the TATA binding protein (TBP) and 14 distinct TBP-associated factors (TAFs). In this report we give a detailed biochemical characterization of this general transcription factor. We have shown that yeast TFIID efficiently mediates both basal and activator-dependent transcription in vitro and displays TATA box binding activity that is functionally distinct from that of TBP. Analyses of the stoichiometry of TFIID subunits indicated that several TAFs are present at more than 1 copy per TFIID complex. This conclusion was further supported by coimmunoprecipitation experiments with a systematic family of (pseudo)diploid yeast strains that expressed epitope-tagged and untagged alleles of the genes encoding TFIID subunits. Based on these data, we calculated a native molecular mass for monomeric TFIID. Purified TFIID behaved in a fashion consistent with this calculated molecular mass in both gel filtration and rate-zonal sedimentation experiments. Quite surprisingly, although the TAF subunits of TFIID cofractionated as a single complex, TBP did not comigrate with the TAFs during either gel filtration chromatography or rate-zonal sedimentation, suggesting that TBP has the ability to dynamically associate with the TFIID TAFs. The results of direct biochemical exchange experiments confirmed this hypothesis. Together, our results represent a concise molecular characterization of the general transcription factor TFIID from S. cerevisiae.
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Affiliation(s)
- Steven L Sanders
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA
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26
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Martel LS, Brown HJ, Berk AJ. Evidence that TAF-TATA box-binding protein interactions are required for activated transcription in mammalian cells. Mol Cell Biol 2002; 22:2788-98. [PMID: 11909971 PMCID: PMC133715 DOI: 10.1128/mcb.22.8.2788-2798.2002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Surfaces of human TATA box-binding protein (hsTBP) required for activated transcription in vivo were defined by constructing a library of surface residue substitution mutations and assaying them for their ability to support activated transcription in transient-transfection assays. In earlier work, three regions were identified where mutations inhibited activated transcription without interfering with TATA box DNA binding. One region is on the upstream surface of the N-terminal TBP repeat with respect to the direction of transcription and corresponds to the TBP surface that interacts with TFIIA. A second region on the stirrup of the C-terminal TBP repeat corresponds to the TFIIB-binding surface. Here we report that the third region where mutations inhibit activated transcription in mammalian cells, the convex surface of the N-terminal repeat, corresponds to a surface on TBP that interacts with hsTAF1, the major scaffold subunit of TFIID. Since mutations at the center of the hsTAF1-interacting region inhibit the ability of the protein to support activated transcription in vivo, these results are consistent with the conclusion that an interaction between hsTBP and TAF(II)s is required for activated transcription in mammalian cells.
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Affiliation(s)
- Lisa S Martel
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California, USA
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27
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Abstract
The last two decades have witnessed a tremendous expansion in our knowledge of the mechanisms employed by eukaryotic cells to control gene activity. A critical insight to transcriptional control mechanisms was provided by the discovery of coactivators, a diverse array of cellular factors that connect sequence-specific DNA binding activators to the general transcriptional machinery, or that help activators and the transcriptional apparatus to navigate through the constraints of chromatin. A number of coactivators have been isolated as large multifunctional complexes, and biochemical, genetic, molecular, and cellular strategies have all contributed to uncovering many of their components, activities, and modes of action. Coactivator functions can be broadly divide into two classes: (a) adaptors that direct activator recruitment of the transcriptional apparatus, (b) chromatin-remodeling or -modifying enzymes. Strikingly, several distinct coactivator complexes nonetheless share many subunits and appear to be assembled in a modular fashion. Such structural and functional modularity could provide the cell with building blocks from which to construct a versatile array of coactivator complexes according to its needs. The extent of functional interplay between these different activities in gene-specific transcriptional regulation is only now becoming apparent, and will remain an active area of research for years to come.
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Affiliation(s)
- A M Näär
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, 401 Barker Hall, University of California, Berkeley, California 94720, USA.
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28
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Abstract
Transcriptional regulation in eukaryotes occurs within a chromatin setting and is strongly influenced by nucleosomal barriers imposed by histone proteins. Among the well-known covalent modifications of histones, the reversible acetylation of internal lysine residues in histone amino-terminal domains has long been positively linked to transcriptional activation. Recent biochemical and genetic studies have identified several large, multisubunit enzyme complexes responsible for bringing about the targeted acetylation of histones and other factors. This review discusses our current understanding of histone acetyltransferases (HATs) or acetyltransferases (ATs): their discovery, substrate specificity, catalytic mechanism, regulation, and functional links to transcription, as well as to other chromatin-modifying activities. Recent studies underscore unexpected connections to both cellular regulatory processes underlying normal development and differentiation, as well as abnormal processes that lead to oncogenesis. Although the functions of HATs and the mechanisms by which they are regulated are only beginning to be understood, these fundamental processes are likely to have far-reaching implications for human biology and disease.
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Affiliation(s)
- S Y Roth
- Department of Biochemistry and Molecular Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
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29
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Banik U, Beechem JM, Klebanow E, Schroeder S, Weil PA. Fluorescence-based analyses of the effects of full-length recombinant TAF130p on the interaction of TATA box-binding protein with TATA box DNA. J Biol Chem 2001; 276:49100-9. [PMID: 11677244 DOI: 10.1074/jbc.m109246200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have used a combination of fluorescence anisotropy spectroscopy and fluorescence-based native gel electrophoresis methods to examine the effects of the transcription factor IID-specific subunit TAF130p (TAF145p) upon the TATA box DNA binding properties of TATA box-binding protein (TBP). Purified full-length recombinant TAF130p decreases TBP-TATA DNA complex formation at equilibrium by competing directly with DNA for binding to TBP. Interestingly, we have found that full-length TAF130p is capable of binding multiple molecules of TBP with nanomolar binding affinity. The biological implications of these findings are discussed.
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Affiliation(s)
- U Banik
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, Nashville, Tennessee 37232-0615, USA
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30
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Durso RJ, Fisher AK, Albright-Frey TJ, Reese JC. Analysis of TAF90 mutants displaying allele-specific and broad defects in transcription. Mol Cell Biol 2001; 21:7331-44. [PMID: 11585915 PMCID: PMC99907 DOI: 10.1128/mcb.21.21.7331-7344.2001] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Yeast TAF90p is a component of at least two transcription regulatory complexes, the general transcription factor TFIID and the Spt-Ada-Gcn5 histone acetyltransferase complex (SAGA). Broad transcription defects have been observed in mutants of other TAF(II)s shared by TFIID and SAGA but not in the only two TAF90 mutants isolated to date. Given that the numbers of mutants analyzed thus far are small, we isolated and characterized 11 temperature-sensitive mutants of TAF90 and analyzed their effects on transcription and integrity of the TFIID and SAGA complexes. We found that the mutants displayed a variety of allele-specific defects in their ability to support transcription and maintain the structure of the TFIID and SAGA complexes. Sequencing of the alleles revealed that all have mutations corresponding to the C terminus of the protein, with most clustering within the conserved WD40 repeats; thus, the C terminus of TAF90p is required for its incorporation into TFIID and function in SAGA. Significantly, inactivation of one allele, taf90-20, caused the dramatic reduction in the levels of total mRNA and most specific transcripts analyzed. Analysis of the structure and/or activity of both TAF90p-containing complexes revealed that this allele is the most disruptive of all. Our analysis defines the requirement for the WD40 repeats in preserving TFIID and SAGA function, demonstrates that the defects associated with distinct mutations in TAF90 vary considerably, and indicates that TAF90 can be classified as a gene required for the transcription of a large number of genes.
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Affiliation(s)
- R J Durso
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802-4500, USA
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31
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Kirchner J, Sanders SL, Klebanow E, Weil PA. Molecular genetic dissection of TAF25, an essential yeast gene encoding a subunit shared by TFIID and SAGA multiprotein transcription factors. Mol Cell Biol 2001; 21:6668-80. [PMID: 11533254 PMCID: PMC99812 DOI: 10.1128/mcb.21.19.6668-6680.2001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have performed a systematic structure-function analysis of Saccharomyces cerevisiae TAF25, an evolutionarily conserved, single-copy essential gene which encodes the 206-amino-acid TAF25p protein. TAF25p is an integral subunit of both the 15-subunit general transcription factor TFIID and the multisubunit, chromatin-acetylating transcriptional coactivator SAGA. We used hydroxylamine mutagenesis, targeted deletion, alanine-scanning mutagenesis, high-copy suppression methods, and two-hybrid screening to dissect TAF25. Temperature-sensitive mutant strains generated were used for coimmunoprecipitation and transcription analyses to define the in vivo functions of TAF25p. The results of these analyses show that TAF25p is comprised of multiple mutable elements which contribute importantly to RNA polymerase II-mediated mRNA gene transcription.
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Affiliation(s)
- J Kirchner
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA
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32
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Mitsuzawa H, Seino H, Yamao F, Ishihama A. Two WD repeat-containing TATA-binding protein-associated factors in fission yeast that suppress defects in the anaphase-promoting complex. J Biol Chem 2001; 276:17117-24. [PMID: 11279037 DOI: 10.1074/jbc.m100248200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The general transcription factor IID consists of the TATA-binding protein (TBP) and multiple TBP-associated factors (TAFs). Here we report the isolation of two related TAF genes from the fission yeast Schizosaccharomyces pombe as multicopy suppressors of a temperature-sensitive mutation in the ubiquitin-conjugating enzyme gene ubcP4(+). The ubcP4(ts) mutation causes cell cycle arrest in mitosis, probably due to defects in ubiquitination mediated by the anaphase-promoting complex/cyclosome. One multicopy suppressor is the previously reported gene taf72(+), whereas the other is a previously unidentified gene named taf73(+). We show that the taf73(+) gene, like taf72(+), is essential for cell viability. The taf72(+) and taf73(+) genes encode proteins homologous to WD repeat-containing TAFs such as human TAF100, Drosophila TAF80/85, and Saccharomyces cerevisiae TAF90. We demonstrate that TAF72 and TAF73 proteins are present in the same complex with TBP and other TAFs and that TAF72, but not TAF73, is associated with the putative histone acetylase Gcn5. We also show that overexpression of TAF72 or TAF73 suppresses the cell cycle arrest in mitosis caused by a mutation in the anaphase-promoting complex/cyclosome subunit gene cut9(+). These results suggest that TAF72 and TAF73 may regulate the expression of genes involved in ubiquitin-dependent proteolysis during mitosis. Our study thus provides evidence for a possible role of WD repeat-containing TAFs in the expression of genes involved in progression through the M phase of the cell cycle.
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Affiliation(s)
- H Mitsuzawa
- Divisions of Molecular Genetics and Mutagenesis, Department of Molecular Genetics, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.
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33
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Uranishi H, Tetsuka T, Yamashita M, Asamitsu K, Shimizu M, Itoh M, Okamoto T. Involvement of the pro-oncoprotein TLS (translocated in liposarcoma) in nuclear factor-kappa B p65-mediated transcription as a coactivator. J Biol Chem 2001; 276:13395-401. [PMID: 11278855 DOI: 10.1074/jbc.m011176200] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we have demonstrated that translocated in liposarcoma (TLS), also termed FUS, is an interacting molecule of the p65 (RelA) subunit of the transcription factor nuclear factor kappaB (NF-kappaB) using a yeast two-hybrid screen. We confirmed the interaction between TLS and p65 by the pull-down assay in vitro and by a coimmunoprecipitation experiment followed by Western blot of the cultured cell in vivo. TLS was originally identified as part of a fusion protein with CHOP arising from chromosomal translocation in human myxoid liposarcomas. TLS has been shown to be involved in TFIID complex formation and associated with RNA polymerase II. However, the role of TLS in transcriptional regulation has not yet been clearly elucidated. We found that TLS enhanced the NF-kappaB-mediated transactivation induced by physiological stimuli such as tumor necrosis factor alpha, interleukin-1beta, and overexpression of NF-kappaB-inducing kinase. TLS augmented NF-kappaB-dependent promoter activity of the intercellular adhesion molecule-1 gene and interferon-beta gene. These results suggest that TLS acts as a coactivator of NF-kappaB and plays a pivotal role in the NF-kappaB-mediated transactivation.
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Affiliation(s)
- H Uranishi
- Department of Molecular Genetics and First Department of Internal Medicine, Nagoya City University Medical School, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan
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34
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Abstract
The assembly of transcription complexes at eukaryotic promoters involves a number of distinct steps including chromatin remodeling, and recruitment of a TATA-binding protein (TBP)-containing complexes, the RNA polymerase II holoenzyme. Each of these stages is controlled by both positive and negative factors. In this review, mechanisms that regulate the interactions of TBP with promoter DNA are described. The first is autorepression, where TBP sequesters its DNA-binding surface through dimerization. Once TBP is bound to DNA, factors such as TAF(II)250 and Mot1 induce TBP to dissociate, while other factors such as NC2 and the NOT complex convert the TBP/DNA complex into an inactive state. TFIIA antagonizes these TBP repressors but may be effective only in conjunction with the recruitment of the RNA polymerase II holoenzyme by promoter-bound activators. Taken together, the ability to induce a gene may depend minimally upon the ability to remodel chromatin as well as alleviate direct repression of TBP and other components of the general transcription machinery. The magnitude by which an activated gene is expressed, and thus repeatedly transcribed, might depend in part on competition between TBP inhibitors and the holoenzyme for access to the TBP/TATA complex.
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Affiliation(s)
- B F Pugh
- Center for Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, 6802, University Park, PA, USA.
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35
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Georgieva SG, Nabirochkina EN, Georgiev PG, Shvarts YB, Soldatov AV. In vivo analysis of theDrosophila melanogaster e(y)1/TAF II40 gene. Mol Biol 2000. [DOI: 10.1007/bf02759605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Mitsiou DJ, Stunnenberg HG. TAC, a TBP-sans-TAFs complex containing the unprocessed TFIIAalphabeta precursor and the TFIIAgamma subunit. Mol Cell 2000; 6:527-37. [PMID: 11030333 DOI: 10.1016/s1097-2765(00)00052-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Transcription of TATA box-containing genes by RNA polymerase II is mediated by TBP-containing and TBP-free multisubunit complexes consisting of common and unique components. We have identified a highly stable TBP-TFIIA-containing complex, TAC, which is detectable in embryonal carcinoma (EC) cells but not in differentiated cells. TAC contains the TFIIAgamma subunit and the unprocessed form of TFIIAalphabeta, although the processed TFIIAalpha and TFIIAbeta subunits are present in EC cells. TAC mediates transcriptional activation by RNA polymerase II in vivo, even though it does not contain classical TAFs. Formaldehyde cross-linking revealed that in EC but not in differentiated cells, association of TBP with chromatin is strongly enhanced when complexed with TFIIA in vivo. Remarkably, the TFIIAalphabeta precursor is preferentially, if not exclusively, associated with chromatin as compared to the processed subunits present in "free" TFIIA in EC cells.
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Affiliation(s)
- D J Mitsiou
- Department of Molecular Biology, University of Nijmegen, The Netherlands
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37
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Ryan MP, Stafford GA, Yu L, Morse RH. Artificially recruited TATA-binding protein fails to remodel chromatin and does not activate three promoters that require chromatin remodeling. Mol Cell Biol 2000; 20:5847-57. [PMID: 10913168 PMCID: PMC86062 DOI: 10.1128/mcb.20.16.5847-5857.2000] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcriptional activators are believed to work in part by recruiting general transcription factors, such as TATA-binding protein (TBP) and the RNA polymerase II holoenzyme. Activation domains also contribute to remodeling of chromatin in vivo. To determine whether these two activities represent distinct functions of activation domains, we have examined transcriptional activation and chromatin remodeling accompanying artificial recruitment of TBP in yeast (Saccharomyces cerevisiae). We measured transcription of reporter genes with defined chromatin structure by artificial recruitment of TBP and found that a reporter gene whose TATA element was relatively accessible could be activated by artificially recruited TBP, whereas two promoters, GAL10 and CHA1, that have accessible activator binding sites, but nucleosomal TATA elements, could not. A third reporter gene containing the HIS4 promoter could be activated by GAL4-TBP only when a RAP1 binding site was present, although RAP1 alone could not activate the reporter, suggesting that RAP1 was needed to open the chromatin structure to allow activation. Consistent with this interpretation, artificially recruited TBP was unable to perturb nucleosome positioning via a nucleosomal binding site, in contrast to a true activator such as GAL4, or to perturb the TATA-containing nucleosome at the CHA1 promoter. Finally, we show that activation of the GAL10 promoter by GAL4, which requires chromatin remodeling, can occur even in swi gcn5 yeast, implying that remodeling pathways independent of GCN5, the SWI-SNF complex, and TFIID can operate during transcriptional activation in vivo.
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Affiliation(s)
- M P Ryan
- Molecular Genetics Program, Wadsworth Center, New York State Department of Health, Albany, New York 12201-2002, USA
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38
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Li B, Reese JC. Derepression of DNA damage-regulated genes requires yeast TAF(II)s. EMBO J 2000; 19:4091-100. [PMID: 10921889 PMCID: PMC306591 DOI: 10.1093/emboj/19.15.4091] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2000] [Revised: 05/22/2000] [Accepted: 06/05/2000] [Indexed: 11/14/2022] Open
Abstract
The general transcription factor TFIID and its individual subunits (TAF(II)s) have been the focus of many studies, yet their functions in vivo are not well established. Here we characterize the requirement of yeast TAF(II)s for the derepression of the ribonucleotide reductase (RNR) genes. Promoter mapping studies revealed that the upstream repressing sequences, the damage-responsive elements (DREs), rendered these genes dependent upon TAF(II)s. DREs are the binding sites for the sequence-specific DNA binding-protein Crt1 that represses transcription by recruiting the Ssn6-Tup1 co-repressor complex to the promoter. We demonstrate that deletion of SSN6, TUP1 or CRT1 alleviated the TAF(II) dependence of the RNR genes, indicating that TAF(II) dependence requires the co-repressor complex. Furthermore, we provide evidence that Crt1 specifies the TAF(II) dependence of these genes. Our studies show that TFIID interacts with the repression domain of Crt1, suggesting that the derepression mechanism involves an antagonism between TFIID and the co-repressor complex. Our results indicate that yeast TAF(II)s have other functions in addition to core promoter selectivity, and describe a novel activity: the derepression of promoters.
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Affiliation(s)
- B Li
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802-4500, USA
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39
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Lim CR, Kimata Y, Ohdate H, Kokubo T, Kikuchi N, Horigome T, Kohno K. The Saccharomyces cerevisiae RuvB-like protein, Tih2p, is required for cell cycle progression and RNA polymerase II-directed transcription. J Biol Chem 2000; 275:22409-17. [PMID: 10787406 DOI: 10.1074/jbc.m001031200] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Two highly conserved RuvB-like putative DNA helicases, p47/TIP49b and p50/TIP49a, have been identified in the eukaryotes. Here, we study the function of Saccharomyces cerevisiae TIH2, which corresponds to mammalian p47/TIP49b. Tih2p is required for vegetative cell growth and localizes in the nucleus. Immunoprecipitation analysis revealed that Tih2p tightly interacts with Tih1p, the counterpart of mammalian p50/TIP49a, which has been shown to interact with the TATA-binding protein and the RNA polymerase II holoenzyme complex. Furthermore, the mutational study of the Walker A motif, which is required for nucleotide binding and hydrolysis, showed that this motif plays indispensable roles in the function of Tih2p. When a temperature-sensitive tih2 mutant, tih2-160, was incubated at the nonpermissive temperature, cells were rapidly arrested in the G(1) phase. Northern blot analysis revealed that Tih2p is required for transcription of G(1) cyclin and of several ribosomal protein genes. The similarities between the mutant phenotypes of tih2-160 and those of taf145 mutants suggest a role for TIH2 in the regulation of RNA polymerase II-directed transcription.
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Affiliation(s)
- C R Lim
- Research and Education Center for Genetic Information and the Division of Gene Function in Animals, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan
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40
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Reese JC, Zhang Z, Kurpad H. Identification of a yeast transcription factor IID subunit, TSG2/TAF48. J Biol Chem 2000; 275:17391-8. [PMID: 10751405 DOI: 10.1074/jbc.m001635200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The RNA polymerase II general transcription factor TFIID is a complex containing the TATA-binding protein (TBP) and associated factors (TAFs). We have used a mutant allele of the gene encoding yeast TAF(II)68/61p to analyze its function in vivo. We provide biochemical and genetic evidence that the C-terminal alpha-helix of TAF(II)68/61p is required for its direct interaction with TBP, the stable incorporation of TBP into the TFIID complex, the integrity of the TFIID complex, and the transcription of most genes in vivo. This is the first evidence that a yeast TAF(II) other than TAF(II)145/130 interacts with TBP, and the implications of this on the interpretation of data obtained studying TAF(II) mutants in vivo are discussed. We have identified a high copy suppressor of the TAF68/61 mutation, TSG2, that has sequence similarity to a region of the SAGA subunit Ada1. We demonstrate that it directly interacts with TAF(II)68/61p in vitro, is a component of TFIID, is required for the stability of the complex in vivo, and is necessary for the transcription of many yeast genes. On the basis of these functions, we propose that Tsg2/TAF(II)48p is the histone 2A-like dimerization partner for the histone 2B-like TAF(II)68/61p in the yeast TFIID complex.
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Affiliation(s)
- J C Reese
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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41
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Wolstein O, Silkov A, Revach M, Dikstein R. Specific interaction of TAFII105 with OCA-B is involved in activation of octamer-dependent transcription. J Biol Chem 2000; 275:16459-65. [PMID: 10828057 DOI: 10.1074/jbc.275.22.16459] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
TAF(II)105 is a TFIID-associated factor highly expressed in B lymphocytes. This subunit is found in a small portion of TFIID complexes and is homologous to human TAF(II)130 and Drosophila TAF(II)110. In the present study we show that TAF(II)105 is involved in transcription activation directed by the B cell-specific octamer element found in many B cell-specific genes. B cells overexpressing TAF(II)105 display higher octamer-dependent transcription, whereas expression of a C-terminal truncated form of TAF(II)105 inhibits octamer transcription in a dominant negative manner. In addition, antibodies directed against TAF(II)105 specifically inhibit octamer-dependent transcription. Reporter gene analysis revealed that TAF(II)105 elevates octamer transcription in the presence of OCA-B, a cofactor subunit of Oct1 and Oct2 proteins. In vitro binding assays and functional studies established that the effect of TAF(II)105 on octamer activity involves interaction of TAF(II)105 with octamer-binding complexes via the C-terminal activation domain of OCA-B. These findings link TAF(II)105 coactivator function to B cell-specific transcription.
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Affiliation(s)
- O Wolstein
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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42
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Sanders SL, Weil PA. Identification of two novel TAF subunits of the yeast Saccharomyces cerevisiae TFIID complex. J Biol Chem 2000; 275:13895-900. [PMID: 10788514 DOI: 10.1074/jbc.275.18.13895] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Using a combination of ion exchange and immunoaffinity chromatography we have purified the general transcription initiation factor TFIID to near homogeneity from Saccharomyces cerevisiae. Yeast TFIID is composed of TBP, the TATA box binding protein, and 14 distinct TBP-associated factors (TAFs), which range in size from 17 to 150 kDa. Twelve of the TAF subunits have been previously identified, but two, TAF48p and TAF65p, are novel. TAF48p exhibits significant sequence similarity to the conserved C-terminal region of Drosophila TAF110p, human TAF130p, and human TAF105p and is encoded by a previously identified gene MPT1. TAF65p shows no significant sequence homology to any previously identified TAFp. The genes encoding TAF48p and TAF65p are single copy and essential for normal yeast cell growth. Furthermore, neither TAF48p nor TAF65p are associated with the histone acetylase Spt-Ada-Gcn5 complex or other non-TFIID TBF.TAF complexes. The significance of these results in terms of TFIID structure, function, and organization is discussed.
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Affiliation(s)
- S L Sanders
- Department of Molecular Physiology & Biophysics, Vanderbilt University, School of Medicine, Nashville, Tennessee 37232-0615, USA
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43
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O'Brien T, Tjian R. Different functional domains of TAFII250 modulate expression of distinct subsets of mammalian genes. Proc Natl Acad Sci U S A 2000; 97:2456-61. [PMID: 10716982 PMCID: PMC15950 DOI: 10.1073/pnas.97.6.2456] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/1999] [Indexed: 12/27/2022] Open
Abstract
The TATA box-binding protein-associated factors (TAFs) are thought to play an essential role in eukaryotic RNA polymerase II transcription by mediating the expression of distinct subsets of genes. In hamster ts13 cells, a single amino acid change in TAF(II)250, which disrupts its acetyl-transferase activity at the restrictive temperature, alters the transcription of specific genes involved in cell cycle control. Likewise, disruption of the amino-terminal kinase domain of TAF(II)250 results in transcriptional defects in ts13 cells. However, it was not known whether the acetyl-transferase or kinase domains of TAF(II)250 modulate specific classes of genes and whether these two domains regulate distinct subsets of genes. Here we have used high-density gene-profiling to identify mammalian transcripts that require either the TAF(II)250 acetyl-transferase or protein kinase function for proper expression. We found that transcription of at least 18% of genes are differentially expressed at the restrictive temperature. The promoter region of one of these genes was subsequently characterized, and both upstream elements as well as the core promoter were shown to be TAF(II)250 responsive. We also found that expression of approximately 6% of genes in ts13 cells requires a functional TAF(II)250 amino-terminal kinase domain, but only approximately 1% of these hamster genes also require the TAF(II)250 acetyl-transferase activity. Our results suggest that the two TAF(II)250 enzymatic activities are important for regulating largely nonoverlapping sets of genes involved in a wide range of biological functions in vivo.
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Affiliation(s)
- T O'Brien
- Department of Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
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44
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Dunphy EL, Johnson T, Auerbach SS, Wang EH. Requirement for TAF(II)250 acetyltransferase activity in cell cycle progression. Mol Cell Biol 2000; 20:1134-9. [PMID: 10648598 PMCID: PMC85231 DOI: 10.1128/mcb.20.4.1134-1139.2000] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The TATA-binding protein (TBP)-associated factor TAF(II)250 is the largest component of the basal transcription factor IID (TFIID). A missense mutation that maps to the acetyltransferase domain of TAF(II)250 induces the temperature-sensitive (ts) mutant hamster cell lines ts13 and tsBN462 to arrest in late G(1). At the nonpermissive temperature (39.5 degrees C), transcription from only a subset of protein encoding genes, including the G(1) cyclins, is dramatically reduced in the mutant cells. Here we demonstrate that the ability of the ts13 allele of TAF(II)250 to acetylate histones in vitro is temperature sensitive suggesting that this enzymatic activity is compromised at 39.5 degrees C in the mutant cells. Mutagenesis of a putative acetyl coenzyme A binding site produced a TAF(II)250 protein that displayed significantly reduced histone acetyltransferase activity but retained TBP and TAF(II)150 binding. Expression of this mutant in ts13 cells was unable to complement the cell cycle arrest or transcriptional defect observed at 39.5 degrees C. These data suggest that TAF(II)250 acetyltransferase activity is required for cell cycle progression and regulates the expression of essential proliferative control genes.
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Affiliation(s)
- E L Dunphy
- Department of Pharmacology, School of Medicine, University of Washington, Seattle, Washington 98195-7280, USA
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45
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Abstract
Synthesis of messenger RNA by RNA polymerase II requires the combined activities of more than 70 polypeptides. Coordinating the interaction of these proteins is the basal transcription factor TFIID, which recognizes the core promoter and supplies a scaffolding upon which the rest of the transcriptional machinery can assemble. A multisubunit complex, TFIID consists of the TATA-binding protein (TBP) and several TBP-associated factors (TAFs), whose primary sequences are well-conserved from yeast to humans. Data from reconstituted cell-free transcription systems and binary interaction assays suggest that the TAF subunits can function as promoter-recognition factors, as coactivators capable of transducing signals from enhancer-bound activators to the basal machinery, and even as enzymatic modifiers of other proteins. Whether TAFs function similarly in vivo, however, has been an open question. Initial characterization of yeast bearing mutations in particular TAFs seemingly indicated that, unlike the situation in vitro, TAFs played only a minor role in transcriptional regulation in vivo. However, reconsideration of this data in light of more recent results from yeast and other organisms reveals considerable convergence between the models derived from in vitro experiments and those derived from in vivo studies. In particular, there is an emerging consensus that TAFs represent one of several classes of coactivators that participate in transcriptional activation in vivo.
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Affiliation(s)
- S R Albright
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720-3204, USA
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46
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Belotserkovskaya R, Sterner DE, Deng M, Sayre MH, Lieberman PM, Berger SL. Inhibition of TATA-binding protein function by SAGA subunits Spt3 and Spt8 at Gcn4-activated promoters. Mol Cell Biol 2000; 20:634-47. [PMID: 10611242 PMCID: PMC85153 DOI: 10.1128/mcb.20.2.634-647.2000] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SAGA is a 1.8-MDa yeast protein complex that is composed of several distinct classes of transcription-related factors, including the adaptor/acetyltransferase Gcn5, Spt proteins, and a subset of TBP-associated factors. Our results indicate that mutations that completely disrupt SAGA (deletions of SPT7 or SPT20) strongly reduce transcriptional activation at the HIS3 and TRP3 genes and that Gcn5 is required for normal HIS3 transcriptional start site selection. Surprisingly, mutations in Spt proteins involved in the SAGA-TBP interaction (Spt3 and Spt8) cause derepression of HIS3 and TRP3 transcription in the uninduced state. Consistent with this finding, wild-type SAGA inhibits TBP binding to the HIS3 promoter in vitro, while SAGA lacking Spt3 or Spt8 is not inhibitory. We detected two distinct forms of SAGA in cell extracts and, strikingly, one lacks Spt8. Conditions that induce HIS3 and TRP3 transcription result in an altered balance between these complexes strongly in favor of the form without Spt8. These results suggest that the composition of SAGA may be dynamic in vivo and may be regulated through dissociable inhibitory subunits.
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47
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Neely KE, Hassan AH, Wallberg AE, Steger DJ, Cairns BR, Wright AP, Workman JL. Activation domain-mediated targeting of the SWI/SNF complex to promoters stimulates transcription from nucleosome arrays. Mol Cell 1999; 4:649-55. [PMID: 10549297 DOI: 10.1016/s1097-2765(00)80216-6] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The yeast SWI/SNF complex is required for the transcription of several yeast genes and has been shown to alter nucleosome structure in an ATP-dependent reaction. In this study, we show that the complex stimulated in vitro transcription from nucleosome templates in an activation domain-dependent manner. Transcription stimulation by SWI/SNF required an activation domain with which it directly interacts. The acidic activation domains of VP16, Gcn4, Swi5, and Hap4 interacted directly with the purified SWI/SNF complex and with the SWI/SNF complex in whole-cell extracts. The similarity of activation domain interactions and transcriptional stimulation between SWI/SNF and the SAGA histone acetyltransferase complex may account for their apparent overlapping functions in vivo.
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Affiliation(s)
- K E Neely
- Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802, USA
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48
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Komarnitsky PB, Michel B, Buratowski S. TFIID-specific yeast TAF40 is essential for the majority of RNA polymerase II-mediated transcription in vivo. Genes Dev 1999; 13:2484-9. [PMID: 10521393 PMCID: PMC317065 DOI: 10.1101/gad.13.19.2484] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/1999] [Accepted: 08/11/1999] [Indexed: 11/24/2022]
Abstract
Many questions remain concerning the role of TFIID TBP-associated factors (TAFs) in transcription, including whether TAFs are required at most or only a small subset of promoters. It was shown previously that three histone-like TAFs are broadly required for transcription, but interpretation of this observation is complicated because these proteins are components of both TFIID and the SAGA histone acetyltransferase complex. Here we show that mutations in the yeast TFIID-specific protein Taf40 lead to a general cessation of transcription, even in the presence of excess TBP, suggesting that the TFIID complex is required at most promoters in vivo.
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Affiliation(s)
- P B Komarnitsky
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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49
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Wu SY, Thomas MC, Hou SY, Likhite V, Chiang CM. Isolation of mouse TFIID and functional characterization of TBP and TFIID in mediating estrogen receptor and chromatin transcription. J Biol Chem 1999; 274:23480-90. [PMID: 10438527 DOI: 10.1074/jbc.274.33.23480] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
TFIID is a general transcription factor required for the assembly of the transcription machinery on most eukaryotic promoters transcribed by RNA polymerase II. Although the TATA-binding subunit (TBP) of TFIID is able to support core promoter and activator-dependent transcription under some circumstances, the roles of TBP-associated factors (TAF(II)s) in TFIID-mediated activation remain unclear. To define the evolutionarily conserved function of TFIID and to elucidate the roles of TAF(II)s in gene activation, we have cloned the mouse TAF(II)55 subunit of TFIID and further isolated mouse TFIID from a murine FM3A-derived cell line that constitutively expresses FLAG-tagged mouse TAF(II)55. Both mouse and human TFIIDs are capable of mediating transcriptional activation by Gal4 fusions containing different activation domains in a highly purified human cell-free transcription system devoid of TFIIA and Mediator. Although TAF(II)-independent activation by Gal4-VP16 can also be observed in this highly purified human transcription system with either mouse or yeast TBP, TAF(II)s are strictly required for estrogen receptor-mediated activation independently of the core promoter sequence. In addition, TAF(II)s are necessary for transcription from a preassembled chromatin template. These findings clearly demonstrate an essential role of TAF(II)s as a transcriptional coactivator for estrogen receptor and in chromatin transcription.
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Affiliation(s)
- S Y Wu
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801, USA
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50
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Shibuya T, Tsuneyoshi S, Azad AK, Urushiyama S, Ohshima Y, Tani T. Characterization of the ptr6(+) gene in fission yeast: a possible involvement of a transcriptional coactivator TAF in nucleocytoplasmic transport of mRNA. Genetics 1999; 152:869-80. [PMID: 10388808 PMCID: PMC1460658 DOI: 10.1093/genetics/152.3.869] [Citation(s) in RCA: 25] [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
Transport of mRNA from the nucleus to the cytoplasm is one of the important steps in gene expression in eukaryotic cells. To elucidate a mechanism of mRNA export, we identified a novel ptr [poly(A)+ RNA transport] mutation, ptr6, which causes accumulation of mRNA in the nucleus and inhibition of growth at the nonpermissive temperature. The ptr6(+) gene was found to encode an essential protein of 393 amino acids, which shares significant homology in amino acid sequence with yTAFII67 of budding yeast Saccharomyces cerevisiae and human hTAFII55, a subunit of the general transcription factor complex TFIID. A Ptr6p-GFP fusion protein is localized in the nucleus, suggesting that Ptr6p functions there. Northern blot analysis using probes for 10 distinct mRNAs showed that the amount of tbp+ mRNA encoding the TATA-binding protein is increased five- to sixfold, whereas amounts of others are rapidly decreased at the nonpermissive temperature in ptr6-1. ptr6 has no defects in nuclear import of an NLS-GFP fusion protein. These results suggest that Ptr6p required for mRNA transport is a Schizosaccharomyces pombe homologue of yTAFII67 and hTAFII55. This is the first report suggesting that a TAF is involved in the nucleocytoplasmic transport of mRNA in addition to the transcription of the protein-coding genes.
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Affiliation(s)
- T Shibuya
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan
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