Project description:RNA immunoprecipitation using mouse monoclonal antibody against human TAF10 protein from HeLa polysome extracts Cells dedicate significant energy to building proteins1, which are often organized in multiprotein assemblies with tightly regulated stoichiometries2. Cotranslational assembly, a process of synchronous translation and protein heterodimerization, is a potential mechanism for efficient matching of partner subunits and avoiding the negative effects of protein aggregation3. Recent studies in bacteria demonstrate that cotranslational assembly of the LuxA-LuxB dimer follows the order established by operon structure and is more efficient than post-translational assembly4. As genes encoding protein complex subunits are dispersed among chromosomes in eukaryotes, it is unclear how cotranslational assembly is accomplished mechanistically, but studies in yeast have nevertheless suggested it as a potential assembly pathway5,6,7. Here we show that mammalian transcription complexes, such as the RNA polymerase II general transcription factor TFIID and the TRanscription and EXport complex-2 (TREX-2) assemble co-translationally. Moreover, we show that the position of heterodimerization domains determines the order of cotranslational assembly in mammalian TFIID. In polysomes, the TATA binding protein associated factor 10 (TAF10), which contains a C-terminal histone-fold dimerization domain (HFD) is recruited cotranslationally to its HFD-containing binding partner TAF8. This interaction is established unidirectionally and determined by the position rather than the sequence of the dimerization domain. We further show that similar mechanisms guide the assembly of other TFIID subunits. Our results thus predict that cotranslational assembly of eukaryotic multisubunit complexes is a general principle in building multiprotein machines. We used microarrays to assess globally the mRNAs associated with TAF10 and TBP immunoprecipitations from HeLa polysomes.
Project description:In eukaryotes, gene expression is performed by three RNA polymerases that are targeted to promoters by molecular complexes. A unique common factor, the TATA-box binding protein (TBP), is thought to serve as a platform to assemble pre-initiation complexes competent for transcription. Herein, we describe a novel molecular mechanism of nutrient regulation of gene transcription by dynamic O-GlcNAcylation of TBP. We show that O-GlcNAcylation at T114 of TBP blocks its interaction with BTAF1, hence the formation of the B-TFIID complex, and its dynamic cycling on and off of DNA. Transcriptomic and metabolomic analyses of TBPT114A CRISPR/Cas9 edited cells showed that loss of O-GlcNAcylation at T114 increases TBP binding to BTAF1 and directly impacts expression of 408 genes. Lack of O-GlcNAcylation at T114 is associated with a striking reprograming of cellular metabolism induced by a profound modification of the transcriptome, leading to gross alterations in lipid storage.
Project description:Using CUT&Tag, a chromatin profiling technique, we show that TBP depletion via IAA surprisingly does not affect RNA Pol II transcription but affects RNA Pol III transcription. Additionally, induction of genes via heat shock and retinoic acid treatment does not require TBP. We also show that a metazoan specific paralog TRF2 does not compensate for TBP for RNA Pol II transcription and that the TFIID subunit of the Pre-initiation Complex can still form with specific subunits still binding onto DNA when TBP is depleted.
Project description:General transcription factor TFIID is a key component of RNA polymerase II transcription initiation in eukaryotic nuclei. Human TFIID is a megadalton-sized multiprotein complex comprising TATA-binding protein (TBP) and 13 TBP-associated factors (TAFs). TBP binds to core promoter DNA, recognizing the TATA-box. A number of transcription regulatory factors were found to compete with DNA for TBP binding. We identified a ternary complex formed by TBP and the histone fold (HF) domain containing TFIID subunits TAF11 and TAF13. We demonstrate that TAF11/TAF13 competes for TBP binding with TATA-box DNA, and also with the N-terminal domain of TAF1. In an integrative approach combing crystal coordinates, biochemical analyses and data from cross-linking mass-spectrometry (CLMS), we determine the architecture of the TAF11/TAF13/TBP complex, revealing TAF11/TAF13 interaction with the DNA binding surface of TBP. Our results thus suggest a novel regulatory state for TFIID function.
Project description:During mitosis, TATA-binding protein(TBP), which remains bound to DNA during mitosis, recruits PP2A and also interacts with a subunit of the condensin complex to allow efficient dephosphorylation and inactivation of condensin near these promoters to inhibit their compaction. These result suggest that TBP function is not only important for expression of genes transcribed bDuring mitosis, TATA-binding protein(TBP), which remains bound to DNA during mitosis, recruits PP2A and also interacts with a subunit of the condensin complex to allow efficient dephosphorylation and inactivation of condensin near these promoters to inhibit their compaction. These result suggest that TBP function is not only important for expression of genes transcribed by all three RNA polymerase during interphase, but also for transmitting the memory of gene activity through mitosis to daughter cellsy all three RNA polymerase during interphase, but also for transmitting the memory of gene activity through mitosis to daughter cells We use ChIP-chip approach to identify TBP-bindind sites in mitotic Jurkat cells at genome-wide level. Input DNA fragments and DNA fragments immunoprecipitated by TBP antibodies by ChIP assay on mitotic Jurkat cells were used to probe the Affymetrix Genechip human tiling 2.0c to identift TBP-binding sites in mitotic Jurkat cells. Input and ChIP sample were replicated three times as following: Input rep1, TBP ChIP1, Input rep2, TBP ChIP2, Input rep3, TBP ChIP3.
Project description:The Swi2/Snf2-family ATPase Mot1 displaces TBP from DNA in vitro, but the global relationship between Mot1 and TBP in vivo has been unclear. We therefore mapped the distribution of Mot1 and TBP on native chromatin at base-pair resolution. Mot1 and TBP binding sites coincide throughout the genome, and depletion of TBP results in a global decrease in Mot1 binding. Using midpoint-versus-length mapping to assess the spatial relationship of Mot1 and TBP on chromatin, we find evidence that Mot1 approaches TBP from the upstream direction, consistent with its in vitro mode of action. Strikingly, inactivation of Mot1 leads to both increases and decreases in TBP-genome association. Sites of TBP gain tend to contain robust TATA boxes, while sites of TBP loss contain poly(dA:dT) tracts that may contribute to nucleosome exclusion. We propose that the action of Mot1 is required to clear TBP from intrinsically preferred (TATA-containing) binding sites, ensuring sufficient soluble TBP to bind intrinsically disfavored (TATA-less) sites.
Project description:The Swi2/Snf2-family ATPase Mot1 displaces TBP from DNA in vitro, but the global relationship between Mot1 and TBP in vivo has been unclear. We therefore mapped the distribution of Mot1 and TBP on native chromatin at base-pair resolution. Mot1 and TBP binding sites coincide throughout the genome, and depletion of TBP results in a global decrease in Mot1 binding. Using midpoint-versus-length mapping to assess the spatial relationship of Mot1 and TBP on chromatin, we find evidence that Mot1 approaches TBP from the upstream direction, consistent with its in vitro mode of action. Strikingly, inactivation of Mot1 leads to both increases and decreases in TBP-genome association. Sites of TBP gain tend to contain robust TATA boxes, while sites of TBP loss contain poly(dA:dT) tracts that may contribute to nucleosome exclusion. We propose that the action of Mot1 is required to clear TBP from intrinsically preferred (TATA-containing) binding sites, ensuring sufficient soluble TBP to bind intrinsically disfavored (TATA-less) sites. We have analyzed the genomic distributions of yeast TBP and Mot1 using Occupied Regions of Genomes from Affinity-purified Naturally Isolated Chromatin and sequencing (ORGANIC-seq).
Project description:During mitosis, TATA-binding protein(TBP), which remains bound to DNA during mitosis, recruits PP2A and also interacts with a subunit of the condensin complex to allow efficient dephosphorylation and inactivation of condensin near these promoters to inhibit their compaction. These result suggest that TBP function is not only important for expression of genes transcribed bDuring mitosis, TATA-binding protein(TBP), which remains bound to DNA during mitosis, recruits PP2A and also interacts with a subunit of the condensin complex to allow efficient dephosphorylation and inactivation of condensin near these promoters to inhibit their compaction. These result suggest that TBP function is not only important for expression of genes transcribed by all three RNA polymerase during interphase, but also for transmitting the memory of gene activity through mitosis to daughter cellsy all three RNA polymerase during interphase, but also for transmitting the memory of gene activity through mitosis to daughter cells