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Rivka Dikstein - One of the best experts on this subject based on the ideXlab platform.
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taf4 4b TAF12 displays a unique mode of dna binding and is required for core promoter function of a subset of genes
Journal of Biological Chemistry, 2009Co-Authors: Kfir Gazit, Irwin Davidson, Sandra Moshonov, Gabrielle Mengus, Rofa Elfakess, Michal Sharon, Rivka DiksteinAbstract:Abstract The major core promoter-binding factor in polymerase II transcription machinery is TFIID, a complex consisting of TBP, the TATA box-binding protein, and 13 to 14 TBP-associated factors (TAFs). Previously we found that the histone H2A-like TAF paralogs TAF4 and TAF4b possess DNA-binding activity. Whether TAF4/TAF4b DNA binding directs TFIID to a specific core promoter element or facilitates TFIID binding to established core promoter elements is not known. Here we analyzed the mode of TAF4b·TAF12 DNA binding and show that this complex binds DNA with high affinity. The DNA length required for optimal binding is ∼70 bp. Although the complex displays a weak sequence preference, the nucleotide composition is less important than the length of the DNA for high affinity binding. Comparative expression profiling of wild-type and a DNA-binding mutant of TAF4 revealed common core promoter features in the down-regulated genes that include a TATA-box and an Initiator. Further examination of the PEL98 gene from this group showed diminished Initiator activity and TFIID occupancy in TAF4 DNA-binding mutant cells. These findings suggest that DNA binding by TAF4/4b-TAF12 facilitates the association of TFIID with the core promoter of a subset of genes.
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TAF4/4b·TAF12 Displays a Unique Mode of DNA Binding and Is Required for Core Promoter Function of a Subset of Genes
Journal of Biological Chemistry, 2009Co-Authors: Kfir Gazit, Irwin Davidson, Sandra Moshonov, Gabrielle Mengus, Rofa Elfakess, Michal Sharon, Rivka DiksteinAbstract:Abstract The major core promoter-binding factor in polymerase II transcription machinery is TFIID, a complex consisting of TBP, the TATA box-binding protein, and 13 to 14 TBP-associated factors (TAFs). Previously we found that the histone H2A-like TAF paralogs TAF4 and TAF4b possess DNA-binding activity. Whether TAF4/TAF4b DNA binding directs TFIID to a specific core promoter element or facilitates TFIID binding to established core promoter elements is not known. Here we analyzed the mode of TAF4b·TAF12 DNA binding and show that this complex binds DNA with high affinity. The DNA length required for optimal binding is ∼70 bp. Although the complex displays a weak sequence preference, the nucleotide composition is less important than the length of the DNA for high affinity binding. Comparative expression profiling of wild-type and a DNA-binding mutant of TAF4 revealed common core promoter features in the down-regulated genes that include a TATA-box and an Initiator. Further examination of the PEL98 gene from this group showed diminished Initiator activity and TFIID occupancy in TAF4 DNA-binding mutant cells. These findings suggest that DNA binding by TAF4/4b-TAF12 facilitates the association of TFIID with the core promoter of a subset of genes.
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Core promoter binding by histone-like TAF complexes.
Molecular and Cellular Biology, 2004Co-Authors: Hanshuang Shao, Merav Revach, Sandra Moshonov, Yael Tzuman, Kfir Gazit, Shira Albeck, Tamar Unger, Rivka DiksteinAbstract:A major function of TFIID is core promoter recognition. TFIID consists of TATA-binding protein (TBP) and 14 TBP-associated factors (TAFs). Most of them contain a histone fold domain (HFD) that lacks the DNA-contacting residues of histones. Whether and how TAF HFDs contribute to core promoter DNA binding are yet unresolved. Here we examined the DNA binding activity of TAF9, TAF6, TAF4b, and TAF12, which are related to histones H3, H4, H2A, and H2B, respectively. Each of these TAFs has intrinsic DNA binding activity adjacent to or within the HFD. The DNA binding domains were mapped to evolutionarily conserved and essential regions. Remarkably, HFD-mediated interaction enhanced the DNA binding activity of each of the TAF6-TAF9 and TAF4b-TAF12 pairs and of a histone-like octamer complex composed of the four TAFs. Furthermore, HFD-mediated interaction stimulated sequence-specific binding by TAF6 and TAF9. These results suggest that TAF HFDs merge with other conserved domains for efficient and specific core promoter binding.
Irwin Davidson - One of the best experts on this subject based on the ideXlab platform.
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TAF4, a subunit of transcription factor II D, directs promoter occupancy of nuclear receptor HNF4A during post-natal hepatocyte differentiation
eLife, 2014Co-Authors: Daniil Alpern, Christophe Romier, Diana Langer, Benoit Ballester, Stéphanie Le Gras, Gabrielle Mengus, Irwin DavidsonAbstract:The functions of the TAF subunits of mammalian TFIID in physiological processes remain poorly characterised. In this study, we describe a novel function of TAFs in directing genomic occupancy of a transcriptional activator. Using liver-specific inactivation in mice, we show that the TAF4 subunit of TFIID is required for post-natal hepatocyte maturation. TAF4 promotes pre-initiation complex (PIC) formation at post-natal expressed liver function genes and down-regulates a subset of embryonic expressed genes by increased RNA polymerase II pausing. The TAF4–TAF12 heterodimer interacts directly with HNF4A and in vivo TAF4 is necessary to maintain HNF4A-directed embryonic gene expression at post-natal stages and promotes HNF4A occupancy of functional cis-regulatory elements adjacent to the transcription start sites of post-natal expressed genes. Stable HNF4A occupancy of these regulatory elements requires TAF4-dependent PIC formation highlighting that these are mutually dependent events. Local promoter-proximal HNF4A–TFIID interactions therefore act as instructive signals for post-natal hepatocyte differentiation. DOI: http://dx.doi.org/10.7554/eLife.03613.001
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taf4 4b TAF12 displays a unique mode of dna binding and is required for core promoter function of a subset of genes
Journal of Biological Chemistry, 2009Co-Authors: Kfir Gazit, Irwin Davidson, Sandra Moshonov, Gabrielle Mengus, Rofa Elfakess, Michal Sharon, Rivka DiksteinAbstract:Abstract The major core promoter-binding factor in polymerase II transcription machinery is TFIID, a complex consisting of TBP, the TATA box-binding protein, and 13 to 14 TBP-associated factors (TAFs). Previously we found that the histone H2A-like TAF paralogs TAF4 and TAF4b possess DNA-binding activity. Whether TAF4/TAF4b DNA binding directs TFIID to a specific core promoter element or facilitates TFIID binding to established core promoter elements is not known. Here we analyzed the mode of TAF4b·TAF12 DNA binding and show that this complex binds DNA with high affinity. The DNA length required for optimal binding is ∼70 bp. Although the complex displays a weak sequence preference, the nucleotide composition is less important than the length of the DNA for high affinity binding. Comparative expression profiling of wild-type and a DNA-binding mutant of TAF4 revealed common core promoter features in the down-regulated genes that include a TATA-box and an Initiator. Further examination of the PEL98 gene from this group showed diminished Initiator activity and TFIID occupancy in TAF4 DNA-binding mutant cells. These findings suggest that DNA binding by TAF4/4b-TAF12 facilitates the association of TFIID with the core promoter of a subset of genes.
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TAF4/4b·TAF12 Displays a Unique Mode of DNA Binding and Is Required for Core Promoter Function of a Subset of Genes
Journal of Biological Chemistry, 2009Co-Authors: Kfir Gazit, Irwin Davidson, Sandra Moshonov, Gabrielle Mengus, Rofa Elfakess, Michal Sharon, Rivka DiksteinAbstract:Abstract The major core promoter-binding factor in polymerase II transcription machinery is TFIID, a complex consisting of TBP, the TATA box-binding protein, and 13 to 14 TBP-associated factors (TAFs). Previously we found that the histone H2A-like TAF paralogs TAF4 and TAF4b possess DNA-binding activity. Whether TAF4/TAF4b DNA binding directs TFIID to a specific core promoter element or facilitates TFIID binding to established core promoter elements is not known. Here we analyzed the mode of TAF4b·TAF12 DNA binding and show that this complex binds DNA with high affinity. The DNA length required for optimal binding is ∼70 bp. Although the complex displays a weak sequence preference, the nucleotide composition is less important than the length of the DNA for high affinity binding. Comparative expression profiling of wild-type and a DNA-binding mutant of TAF4 revealed common core promoter features in the down-regulated genes that include a TATA-box and an Initiator. Further examination of the PEL98 gene from this group showed diminished Initiator activity and TFIID occupancy in TAF4 DNA-binding mutant cells. These findings suggest that DNA binding by TAF4/4b-TAF12 facilitates the association of TFIID with the core promoter of a subset of genes.
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TATA box-binding protein-associated factor 12 is important for RAS-induced transformation properties of colorectal cancer cells.
Molecular Cancer Research, 2008Co-Authors: Angeliki Voulgari, Laszlo Tora, Irwin Davidson, Stella Voskou, Takehiko Sasazuki, Senji Shirasawa, Alexander PintzasAbstract:Activating mutations in the RAS proto-oncogene result in constant stimulation of its downstream pathways, further leading to tumorigenesis. Transcription factor IID (TFIID) can be regulated by cellular signals to specifically alter transcription of particular subsets of genes. To investigate potential links between the regulation of TFIID function and the RAS-induced carcinogenesis, we monitored the expression of the TATA box-binding protein and its associated factors (TAF) in human colon carcinoma cells. We primarily identified TAF12 levels as being up-regulated in cell lines bearing natural RAS mutations or stably overexpressing a mutated RAS isoform via a mitogen-activated protein kinase/extracellular signal-regulated kinase kinase–dependent pathway. We further showed by electrophoretic mobility shift assays and chromatin immunoprecipitation that the ETS1 protein was interacting with an ETS-binding site on the TAF12 promoter and was regulating TAF12 expression. The binding was enhanced in extracts from oncogenic RAS-transformed cells, pointing to a role in the RAS-mediated regulation of TAF12 expression. Reduction of TAF12 levels by small interfering RNA treatment induced a destabilization of the TFIID complex, enhanced E-cadherin mRNA and protein levels, and reduced migration and adhesion properties of RAS-transformed cells with epithelial to mesenchymal transition. Overall, our study indicates the importance of TAF12 in the process of RAS-induced transformation properties of human colon cells and epithelial to mesenchymal transition, most notably those related to increased motility, by regulating specifically expression of genes such as E-cadherin . (Mol Cancer Res 2008;6(6):1071–83)
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A functional interaction between ATF7 and TAF12 that is modulated by TAF4
Oncogene, 2005Co-Authors: Pierre-jacques Hamard, Irwin Davidson, Rozenn Dalbies-tran, Charlotte Hauss, Claude Kedinger, Bruno ChattonAbstract:The ATF7 proteins, which are members of the cyclic AMP responsive binding protein (CREB)/activating transcription factor (ATF) family of transcription factors, display quite versatile properties: they can interact with the adenovirus E1a oncoprotein, mediating part of its transcriptional activity; they heterodimerize with the Jun, Fos or related transcription factors, likely modulating their DNA-binding specificity; they also recruit to the promoter a stress-induced protein kinase (JNK2). In the present study, we investigate the functional relationships of ATF7 with hsTAF12 (formerly hsTAF_II20/15), which has originally been identified as a component of the general transcription factor TFIID. We show that overexpression of hsTAF12 potentiates ATF7-induced transcriptional activation through direct interaction with ATF7, suggesting that TAF12 is a functional partner of ATF7. In support of this conclusion, chromatin immunoprecipitation experiments confirm the interaction of ATF7 with TAF12 on an ATF7-responsive promoter, in the absence of any artificial overexpression of both proteins. We also show that the TAF12-dependent transcriptional activation is competitively inhibited by TAF4. Although both TAF12 isoforms (TAF12-1 and -2, formerly TAF_II20 and TAF_II15) interact with the ATF7 activation region through their histone-fold domain, only the largest, hsTAF12-1, mediates transcriptional activation through its N-terminal region.
Tetsuro Kokubo - One of the best experts on this subject based on the ideXlab platform.
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Multiple direct interactions of TBP with the MYC oncoprotein
Nature Structural & Molecular Biology, 2019Co-Authors: Diana Resetca, Zhe Li, Isak Johansson-Åkhe, Alexandra Ahlner, Sara Helander, Amelie Wallenhammar, Vivian Morad, Brian Raught, Björn Wallner, Tetsuro KokuboAbstract:Transcription factor c-MYC is a potent oncoprotein; however, the mechanism of transcriptional regulation via MYC-protein interactions remains poorly understood. The TATA-binding protein (TBP) is an essential component of the transcription initiation complex TFIID and is required for gene expression. We identify two discrete regions mediating MYC-TBP interactions using structural, biochemical and cellular approaches. A 2.4 -Å resolution crystal structure reveals that human MYC amino acids 98–111 interact with TBP in the presence of the amino-terminal domain 1 of TBP-associated factor 1 (TAF1^TAND1). Using biochemical approaches, we have shown that MYC amino acids 115–124 also interact with TBP independently of TAF1^TAND1. Modeling reveals that this region of MYC resembles a TBP anchor motif found in factors that regulate TBP promoter loading. Site-specific MYC mutants that abrogate MYC-TBP interaction compromise MYC activity. We propose that MYC-TBP interactions propagate transcription by modulating the energetic landscape of transcription initiation complex assembly. Structural, biophysical and modeling approaches, combined with cell-based assays, reveal how the oncogenic transcription factor MYC interacts with subunits of the general transcription factor TFIID to modulate gene expression.
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mutations in the histone fold domain of the TAF12 gene show synthetic lethality with the taf1 gene lacking the taf n terminal domain tand by different mechanisms from those in the spt15 gene encoding the tata box binding protein tbp
Nucleic Acids Research, 2003Co-Authors: Akiko Kobayashi, Tsuyoshi Miyake, Masashi Kawaichi, Tetsuro KokuboAbstract:The general transcription factor TFIID, composed of the TATA box-binding protein (TBP) and 14 TBP-associated factors (TAFs), is important for both basal and regulated transcription by RNA polymerase II. Although it is well known that the TAF N-terminal domain (TAND) at the amino-terminus of the TAF1 protein binds to TBP and thereby inhibits TBP function in vitro, the physiological role of this domain remains obscure. In our previous study, we screened for mutations that cause lethality when co-expressed with the TAF1 gene lacking TAND (taf1-ΔTAND) and identified two ΔTAND synthetic lethal (nsl) mutations as those in the SPT15 gene encoding TBP. In this study we isolated another nsl mutation in the same screen and identified it to be a mutation in the histone fold domain (HFD) of the TAF12 gene. Several other HFD mutations of this gene also exhibit nsl phenotypes, and all of them are more or less impaired in transcriptional activation in vivo. Interestingly, a set of genes affected in the taf1-ΔTAND mutant is similarly affected in the TAF12 HFD mutants but not in the nsl mutants of TBP. Therefore, we discovered that the nsl mutations of these two genes cause lethality in the taf1-ΔTAND mutant by different mechanisms.
Kfir Gazit - One of the best experts on this subject based on the ideXlab platform.
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taf4 4b TAF12 displays a unique mode of dna binding and is required for core promoter function of a subset of genes
Journal of Biological Chemistry, 2009Co-Authors: Kfir Gazit, Irwin Davidson, Sandra Moshonov, Gabrielle Mengus, Rofa Elfakess, Michal Sharon, Rivka DiksteinAbstract:Abstract The major core promoter-binding factor in polymerase II transcription machinery is TFIID, a complex consisting of TBP, the TATA box-binding protein, and 13 to 14 TBP-associated factors (TAFs). Previously we found that the histone H2A-like TAF paralogs TAF4 and TAF4b possess DNA-binding activity. Whether TAF4/TAF4b DNA binding directs TFIID to a specific core promoter element or facilitates TFIID binding to established core promoter elements is not known. Here we analyzed the mode of TAF4b·TAF12 DNA binding and show that this complex binds DNA with high affinity. The DNA length required for optimal binding is ∼70 bp. Although the complex displays a weak sequence preference, the nucleotide composition is less important than the length of the DNA for high affinity binding. Comparative expression profiling of wild-type and a DNA-binding mutant of TAF4 revealed common core promoter features in the down-regulated genes that include a TATA-box and an Initiator. Further examination of the PEL98 gene from this group showed diminished Initiator activity and TFIID occupancy in TAF4 DNA-binding mutant cells. These findings suggest that DNA binding by TAF4/4b-TAF12 facilitates the association of TFIID with the core promoter of a subset of genes.
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TAF4/4b·TAF12 Displays a Unique Mode of DNA Binding and Is Required for Core Promoter Function of a Subset of Genes
Journal of Biological Chemistry, 2009Co-Authors: Kfir Gazit, Irwin Davidson, Sandra Moshonov, Gabrielle Mengus, Rofa Elfakess, Michal Sharon, Rivka DiksteinAbstract:Abstract The major core promoter-binding factor in polymerase II transcription machinery is TFIID, a complex consisting of TBP, the TATA box-binding protein, and 13 to 14 TBP-associated factors (TAFs). Previously we found that the histone H2A-like TAF paralogs TAF4 and TAF4b possess DNA-binding activity. Whether TAF4/TAF4b DNA binding directs TFIID to a specific core promoter element or facilitates TFIID binding to established core promoter elements is not known. Here we analyzed the mode of TAF4b·TAF12 DNA binding and show that this complex binds DNA with high affinity. The DNA length required for optimal binding is ∼70 bp. Although the complex displays a weak sequence preference, the nucleotide composition is less important than the length of the DNA for high affinity binding. Comparative expression profiling of wild-type and a DNA-binding mutant of TAF4 revealed common core promoter features in the down-regulated genes that include a TATA-box and an Initiator. Further examination of the PEL98 gene from this group showed diminished Initiator activity and TFIID occupancy in TAF4 DNA-binding mutant cells. These findings suggest that DNA binding by TAF4/4b-TAF12 facilitates the association of TFIID with the core promoter of a subset of genes.
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Core promoter binding by histone-like TAF complexes.
Molecular and Cellular Biology, 2004Co-Authors: Hanshuang Shao, Merav Revach, Sandra Moshonov, Yael Tzuman, Kfir Gazit, Shira Albeck, Tamar Unger, Rivka DiksteinAbstract:A major function of TFIID is core promoter recognition. TFIID consists of TATA-binding protein (TBP) and 14 TBP-associated factors (TAFs). Most of them contain a histone fold domain (HFD) that lacks the DNA-contacting residues of histones. Whether and how TAF HFDs contribute to core promoter DNA binding are yet unresolved. Here we examined the DNA binding activity of TAF9, TAF6, TAF4b, and TAF12, which are related to histones H3, H4, H2A, and H2B, respectively. Each of these TAFs has intrinsic DNA binding activity adjacent to or within the HFD. The DNA binding domains were mapped to evolutionarily conserved and essential regions. Remarkably, HFD-mediated interaction enhanced the DNA binding activity of each of the TAF6-TAF9 and TAF4b-TAF12 pairs and of a histone-like octamer complex composed of the four TAFs. Furthermore, HFD-mediated interaction stimulated sequence-specific binding by TAF6 and TAF9. These results suggest that TAF HFDs merge with other conserved domains for efficient and specific core promoter binding.
David W Dempster - One of the best experts on this subject based on the ideXlab platform.
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role of atf7 TAF12 interactions in the vdr hyper sensitivity of osteoclast precursors in paget s disease
Journal of Bone and Mineral Research, 2013Co-Authors: Jumpei Teramachi, Yuko Hiruma, Seiichi Ishizuka, Hisako Ishizuka, Jacques P Brown, Laetitia Michou, Deborah L Galson, Mark A Subler, Hua Zhou, David W DempsterAbstract:Osteoclast (OCL) precursors from many Paget's disease (PD) patients express measles virus nucleocapsid protein (MVNP) and are hypersensitive to 1,25-(OH)2D3. The increased 1,25-(OH)2D3 sensitivity is mediated by TAF12, a co-activator of VDR, which is present at much higher levels in MVNP-expressing OCL precursors than normals. These results suggest that TAF12 plays an important role in the abnormal OCL activity in PD. However, the molecular mechanisms underlying both 1,25-(OH)2D3’s effects on OCL formation and the contribution of TAF12 to these effects in both normals and PD patients are unclear. Inhibition of TAF12 with a specific TAF12 antisense construct decreased OCL formation and OCL precursors sensitivity to 1,25-(OH)2D3 in PD patient bone marrow samples. Further, OCL-precursors from transgenic mice in which TAF12 expression was targeted to the OCL lineage (TRAP-TAF12 mice), formed OCL at very low levels of 1,25-(OH)2D3, although the OCL failed to exhibit other hallmarks of PD OCL, including RANKL hyper-sensitivity and hyper-multinucleation. ChIP analysis of OCL precursors using an anti-TAF12 antibody demonstrated that TAF12 binds the 24-hydroxylase (CYP24A1) promoter, which contains two functional vitamin D response elements (VDRE), in the presence of 1,25-(OH)2D3. Since TAF12 directly interacts with the ATF7 transcription factor and potentiates ATF7-induced transcriptional activation of ATF7-driven genes in other cell types, we determined if TAF12 is a functional partner of ATF7 in OCL precursors. Immunoprecipitation of lysates from either WT or MVNP-expressing OCL with an anti-TAF12 antibody followed by blotting with an anti-ATF7 antibody, or vice versa, showed that TAF12 and ATF7 physically interact in OCL. Knockdown of ATF7 in MVNP-expressing cells decreased CYP24A1 induction by 1,25-(OH)2D3 as well as TAF12 binding to the CYP24A1 promoter. These results show that ATF7 interacts with TAF12 and contributes to the hyper-sensitivity of OCL precursors to 1,25-(OH)2D3 in PD.
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role of atf7 TAF12 interactions in the vitamin d response hypersensitivity of osteoclast precursors in paget s disease
Journal of Bone and Mineral Research, 2013Co-Authors: Jumpei Teramachi, Yuko Hiruma, Seiichi Ishizuka, Hisako Ishizuka, Jacques P Brown, Laetitia Michou, Deborah L Galson, Mark A Subler, Hua Zhou, David W DempsterAbstract:Osteoclast (OCL) precursors from many Paget's disease (PD) patients express measles virus nucleocapsid protein (MVNP) and are hypersensitive to 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3; also know as calcitriol). The increased 1,25-(OH)2D3 sensitivity is mediated by transcription initiation factor TFIID subunit 12 (TAF12), a coactivator of the vitamin D receptor (VDR), which is present at much higher levels in MVNP-expressing OCL precursors than normals. These results suggest that TAF12 plays an important role in the abnormal OCL activity in PD. However, the molecular mechanisms underlying both 1,25-(OH)2D3's effects on OCL formation and the contribution of TAF12 to these effects in both normals and PD patients are unclear. Inhibition of TAF12 with a specific TAF12 antisense construct decreased OCL formation and OCL precursors' sensitivity to 1,25-(OH)2D3 in PD patient bone marrow samples. Further, OCL precursors from transgenic mice in which TAF12 expression was targeted to the OCL lineage (tartrate-resistant acid phosphatase [TRAP]-TAF12 mice), formed OCLs at very low levels of 1,25-(OH)2D3, although the OCLs failed to exhibit other hallmarks of PD OCLs, including receptor activator of NF-κB ligand (RANKL) hypersensitivity and hypermultinucleation. Chromatin immunoprecipitation (ChIP) analysis of OCL precursors using an anti-TAF12 antibody demonstrated that TAF12 binds the 24-hydroxylase (CYP24A1) promoter, which contains two functional vitamin D response elements (VDREs), in the presence of 1,25-(OH)2D3. Because TAF12 directly interacts with the cyclic adenosine monophosphate–dependent activating transcription factor 7 (ATF7) and potentiates ATF7-induced transcriptional activation of ATF7-driven genes in other cell types, we determined whether TAF12 is a functional partner of ATF7 in OCL precursors. Immunoprecipitation of lysates from either wild-type (WT) or MVNP-expressing OCL with an anti-TAF12 antibody, followed by blotting with an anti-ATF7 antibody, or vice versa, showed that TAF12 and ATF7 physically interact in OCLs. Knockdown of ATF7 in MVNP-expressing cells decreased cytochrome P450, family 24, subfamily A, polypeptide 1 (CYP24A1) induction by 1,25-(OH)2D3, as well as TAF12 binding to the CYP24A1 promoter. These results show that ATF7 interacts with TAF12 and contributes to the hypersensitivity of OCL precursors to 1,25-(OH)2D3 in PD.