Single residues in the histone core domain guide transcription elongation
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PROVIDER: PRJNA1177433 | ENA |
REPOSITORIES: ENA
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Project description:Single residues in the histone core domain guide transcription
| PRJNA1174139 | ENA
Project description:Transcription activity is tightly correlated with a stereotypical suite of chromatin features and modifications, but how/if these are interpreted by transcriptional machinery remains poorly understood. The presence of the histone variants such as H2A.Z is one such feature, known to change the biophysical properties of chromatin. Here we couple phylogenetic analysis to synthetic biology to establish that H2A.Z tunes RNA polymerase II elongation activity through a direct interaction with the transcription machinery. We show that evolution-derived sequence variation in only seven residues located in the short unstructured loop 2 (L2) region of H2A.Z affects RNA polymerase II elongation rates through physical interaction with transcription elongation factor Spt6. Our results establish a direct physical and functional link between transcription and its chromatinized template. Moreover, we proposed that species-specific variations in H2A.Z L2 change the ground state level of transcription and could be exploited for the creation of emergent properties of chromatin.
2025-06-30 | GSE280242 | GEO
Project description:The nucleosome is thought to suppress transcription in eukaryotes by acting as a structural barrier. However, once begun, transcription can readily proceed in the presence of nucleosomes, suggesting this model is insufficient. Here, we establish that the ultra-conserved core domain of the ancestral histone H2A.Z informs transcription elongation via direct interaction of its loop 2 region with the transcription elongation factor Spt6. Interrogating H2A.Z sequences representing more than a billion years of eukaryotic evolution in a single synthetic host, we show that Spt6 can distinguish even single-residue substitutions within their loop 2, controlling RNAPII processivity. Our results place the histone core domain at the origin of eukaryotic gene expression, establishing it as a powerful force shaping transcription.
2025-06-30 | GSE279717 | GEO
Project description:Cyclin-dependent kinase 12 (CDK12) phosphorylates the carboxyl-terminal domain (CTD) of RNA polymerase II (pol II) but its roles in transcription beyond the expression of DNA damage response genes remain unclear. Here, we have used TT-seq and mNET-seq to monitor the direct effects of rapid CDK12 inhibition on transcription activity and CTD phosphorylation in human cells. CDK12 inhibition causes a genome-wide defect in transcription elongation and a global reduction of CTD Ser2 and Ser5 phosphorylation. The elongation defect is explained by the loss of the elongation factors LEO1 and CDC73, part of PAF1 complex, and SPT6 from the newly-elongating pol II. Our results indicate that CDK12 is a general activator of pol II transcription elongation and indicate that it targets both Ser2 and Ser5 residues of the pol II CTD.
2020-06-03 | GSE115290 | GEO
Project description:Cyclin-dependent kinase 12 (CDK12) phosphorylates the carboxyl-terminal domain (CTD) of RNA polymerase II (pol II) but its roles in transcription beyond the expression of DNA damage response genes remain unclear. Here, we have used TT-seq and mNET-seq to monitor the direct effects of rapid CDK12 inhibition on transcription activity and CTD phosphorylation in human cells. CDK12 inhibition causes a genome-wide defect in transcription elongation and a global reduction of CTD Ser2 and Ser5 phosphorylation. The elongation defect is explained by the loss of the elongation factors LEO1 and CDC73, part of PAF1 complex, and SPT6 from the newly-elongating pol II. Our results indicate that CDK12 is a general activator of pol II transcription elongation and indicate that it targets both Ser2 and Ser5 residues of the pol II CTD.
2020-06-18 | GSE133156 | GEO
Project description:The conserved transcription elongation factor Spt6 makes several contacts with the RNA Polymerase II (RNAPII) complex, including a high-affinity interaction between the Spt6 tandem SH2 domain (Spt6-tSH2) and phosphorylated residues in Rpb1 in a region between the catalytic core and the heptad repeats of its C-terminal domain (CTD). This interaction contributes to the global occupancy of Spt6 within transcription units, suggesting that it has a general role in tethering Spt6 to the elongation complex. However, we show here that disrupting this binding caused increases in some transcripts, revealing specific functional roles in regulating the expression of subsets of genes. These included loci whose regulation involves differential transcription start site selection, early termination of transcription, or efficient restoration of chromatin integrity after transcription. Loss of this interaction also caused a defect in splicing, and apparent pausing of RNAPII progression in regions requiring more complex processing of excised introns. The results support a global role for the Spt6-tSH2:Rpb1 interaction as one of several means of stabilizing the association of Spt6 with RNAPII, but they also reveal local functions at specific sites, especially those where dynamic decisions regarding initiation or termination are made, or where changes in the configuration of associated factors occur. We therefore propose that the Spt6-tSH2:Rpb1 interaction can provide a conduit for communication between RNAPII and the elongation factor function of Spt6, or with other factors associated with the Rpb1 CTD, supporting appropriate elongation through challenging templates and efficient co-transcriptional processing.
2021-12-20 | GSE174427 | GEO
Project description:Dynamic post-translational modification of RNA polymerase II (RNAPII) coordinates the co-transcriptional recruitment of enzymatic complexes that regulate chromatin states and co-transcriptional processing of nascent RNA. Extensive phosphorylation of serine residues occurs at the structurally-disordered C-terminal domain (CTD) of the largest RNAPII subunit, which is composed of multiple heptapeptide repeats with consensus sequence Y1-S2-P3-T4-S5-P6-S7. Serine-5 and Serine-7 phosphorylation mark transcription initiation, whereas Serine-2 phosphorylation coincides with productive elongation. In vertebrates, the CTD has eight non-canonical substitutions of Serine-7 into Lysine-7, which can be acetylated (K7ac). Here, we describe for the first time mono- and di-methylation of CTD Lysine-7 residues (K7me1 and K7me2). K7me1 and K7me2 are observed during the earliest transcription stages and precede or accompany Serine-5 and Serine-7 phosphorylation. Genome wide mapping of 2 novel RNAPII post-translational modifications (CTD-K7me1 and CTD-K7me2) in mouse ES cells.
2015-12-22 | E-GEOD-72876 | biostudies-arrayexpress
Project description:Dynamic modification of the carboxy-terminal domain (CTD) of RNA polymerase II (RNAPII) regulates transcription-coupled processes in eukaryotes. The CTD in mammals is composed of 52 heptad-repeats with the consensus sequence Y1-S2-P3-T4-S5-P6-S7. Repeats in the distal part of CTD deviate from the consensus sequence and have frequently replaced serine at position 7 by lysine residues (K7). Mass spectrometry analysis revealed modification of K7 residues in heptad-repeats 39, 42, and 47/49 by acetylation and in heptad-repeats 38, 39, 40, 42, and 47/49 by mono-, di-, or trimethylation. Notably, acetylated as well as di- and tri-methylated K7 residues were found exclusively in phosphorylated CTD peptides, while mono-methylated K7 residues occurred also in non-phosphorylated CTD peptides. Methylation of K7 residues was further studied with the monoclonal antibody (mAb) 1F5, which recognizes mono- and di-methylated K7 in CTD. ChIP experiments revealed high levels of K7 methylation at the transcriptional start site of genes. The low levels of K7 methylation in the body of genes results from impairment of epitope recognition in hyper-phosphorylated CTD by mAb 1F5. In agreement with this notion, phosphatase treatment of hyper-phosphorylated CTD or treatment of cells with kinase inhibitor flavopiridol restored the reactivity of mAb 1F5 towards methylated K7 residues in CTD. We conclude that methylation and acetylation of K7 residues further expand the mammalian CTD code and potentially contribute to regulation of gene expression.
2015-12-01 | GSE72698 | GEO
Project description:Cancer arises from the malignant interplay between oncogenic signaling and cell specification. Transcriptionally activated stem, growth and survival programs reshape an epigenomic identity defined by a transcriptional core regulatory circuitry. To study and disrupt oncogenic transcription, we first created inhibitors of BET bromodomains. Selective antagonism of oncogenic transcriptional signaling arises from bromodomain-specific activity. Recently, we innovated a strategy to induce selective and pronounced degradation of BET coactivator proteins via phthalimide conjugation for E3 ubiquitin ligase recruitment. Degraders of BET bromdomains (dBETs) exhibited superior efficacy to bromodomain inhibitors in cultivated leukemia cells, through unknown mechanisms. Here, we use chemically optimized small-molecule degronimids and kinetic measures of chromatin structure and function to unveil an unrecognized, essential role for BRD4 in the control of global productive transcriptional elongation. Rapid loss of BRD4 attenuates phosphorylation of the carboxy-terminal domain of RNA polymerase II, independent of genomewide recruitment of CDK9 to promoters, leading to a collapse of the transcriptional core regulatory circuitry. These mechanistic studies are performed in translational models of T-cell acute lymphoblastic leukemia, a disease emblematic for transcriptional addiction, to establish a rationale for human clinical investigation. RNA-Seq for DMSO, dBET6, or JQ1 treated MOLT4 cells
2016-04-01 | E-GEOD-79253 | biostudies-arrayexpress
Project description:The conserved transcription elongation factor Spt6 makes several contacts with the RNA Polymerase II (RNAPII) complex, including a high-affinity interaction between the Spt6 tandem SH2 domain (Spt6-tSH2) and phosphorylated residues of the Rpb1 subunit in the linker between the catalytic core and the C-terminal domain (CTD) heptad repeats. This interaction contributes to generic localization of Spt6, but we show here that it also has gene-specific roles. Disrupting the interface affected transcription start site selection at a subset of genes whose expression is regulated by this choice, and this was accompanied by changes in a distinct pattern of Spt6 accumulation at these sites. Splicing efficiency was also diminished, as was apparent progression through introns that encode snoRNAs. Chromatin-mediated repression was impaired, and a distinct role in maintaining +1 nucleosomes was identified, especially at ribosomal protein genes. The Spt6-tSH2:Rpb1 interface therefore has both genome-wide functions and local roles at subsets of genes where dynamic decisions regarding initiation, transcript processing, or termination are made. We propose that the interaction modulates the availability or activity of the core elongation and histone chaperone functions of Spt6, contributing to coordination between RNAPII and its accessory factors as varying local conditions call for dynamic responses.
2021-12-20 | GSE189831 | GEO