Single residues in the histone core domain guide transcription
Ontology highlight
ABSTRACT:
ORGANISM(S): Schizosaccharomyces pombe
PROVIDER: GSE279717 | GEO | 2025/06/30
REPOSITORIES: GEO
Similar Datasets
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:Single residues in the histone core domain guide transcription elongation
| PRJNA1177433 | 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 | GSE265775 | GEO
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 | GSE265749 | GEO
Project description:H2A.Z is a highly conserved histone variant involved in several key nuclear processes. It is incorporated into promoters by SWR-C-related chromatin remodeling complexes, but whether it is also actively excluded from non-promoter regions is not clear. Here, we provide genomic and biochemical evidence that RNA polymerase II (RNAPII) elongation-associated histone chaperones FACT and Spt6 both contribute to restricting H2A.Z from intragenic regions. In the absence of FACT or Spt6, the lack of H2A.Z eviction, coupled to its pervasive incorporation by mislocalized SWR-C, alters chromatin composition and contributes to cryptic initiation. Thus, chaperone-mediated H2A.Z removal is crucial for restricting the chromatin signature of gene promoters, which otherwise may license or promote cryptic transcription. We profiled H2A.Z occupancy in S. cerevisiae by ChIP-chip on tiling arrays in different mutants for chromatin remodelers and histone chaperones. In most experiments, H2A.Z ChIP samples (Cy5-labeled) were performed using a polyclonal antibody against H2A.Z and hybridized against H2B ChIP samples (Cy3-labeled), also performed using a polyclonal antibody. Temperature-sensitive mutants for the histone chaperones Spt16 and Spt6 (spt16-197 and spt6-1004 respectively) showed strong H2A.Z localization defects so the role of these factors in H2A.Z localization was further analyzed. H2A.Z ChIP-chip experiments in spt16-197 and spt6-1004 were repeated using different experimental designs [normalized against Input DNA or Mock (IgG) ChIP samples]. The contribution of Spt16 and Spt6 on H2A.Z localization was also confirmed by nuclear depletion of Spt16 and Spt6 using the anchor-away system. H2A.Z ChIP-chip experiments were also performed in sic1Δ and spt16-197/sic1Δ cells in order to rule out any G1-arrest artifact. H2A.Z ChIP-chip experiments were repeated using spike-in controls for normalization, revealing widespread H2A.Z occupancy in Spt16 and Spt6 mutants. In addition, the localization of the chromatin remodeler SWR-C was determined in wild type cells as well as in spt16-197 and spt6-1004 cells. Finally, we also profiled histone H4 occupancy by ChIP-chip in wild type, spt16-197, spt6-1004, spt16-197/htz1Δ and spt6-1004/htz1Δ cells. All ChIP-chip experiments were done in duplicates. Each microarray was normalized using the Lima Loess and replicates were combined using a weighted average method as previously described (Pokholok et al., 2005).
2015-05-12 | E-GEOD-62880 | 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
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:The disassembly and reassembly of nucleosomes by histone chaperones is an essential activity during eukaryotic transcription elongation. This highly conserved process maintains chromatin integrity by transiently removing nucleosomes as barriers and then restoring them in the wake of transcription. While transcription elongation requires multiple histone chaperones, there is little understanding of how most of them function and why so many are required. Here, we show that the histone chaperone Spt6 acts through its acidic, intrinsically disordered N-terminal domain (NTD) to bind histones and control chromatin structure. The Spt6 NTD is essential for viability and its histone binding activity is conserved between yeast and humans. The essential nature of the Spt6 NTD can be bypassed by changes in another histone chaperone, FACT, revealing a close functional connection between the two. Our results have led to a mechanistic model for dynamic cooperation between multiple histone chaperones during transcription elongation.
2024-11-25 | GSE282380 | GEO
Project description:The disassembly and reassembly of nucleosomes by histone chaperones is an essential activity during eukaryotic transcription elongation. This highly conserved process maintains chromatin integrity by transiently removing nucleosomes as barriers and then restoring them in the wake of transcription. While transcription elongation requires multiple histone chaperones, there is little understanding of how most of them function and why so many are required. Here, we show that the histone chaperone Spt6 acts through its acidic, intrinsically disordered N-terminal domain (NTD) to bind histones and control chromatin structure. The Spt6 NTD is essential for viability and its histone binding activity is conserved between yeast and humans. The essential nature of the Spt6 NTD can be bypassed by changes in another histone chaperone, FACT, revealing a close functional connection between the two. Our results have led to a mechanistic model for dynamic cooperation between multiple histone chaperones during transcription elongation.
2024-11-25 | GSE282379 | 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 of the Rpb1 subunit in a region linking the catalytic core and the heptad repeats at the C-terminal domain (CTD). 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 the distinct pattern of Spt6 occupancy at these sites. Splicing efficiency was also impacted, as was apparent progression through introns that encode snoRNAs. Expression of genes that are particularly sensitive to efficient restoration of chromatin after transcription were affected, 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 Spt6-tSH2:Rpb1 interaction participates in coordinating appropriate responses to the varying local conditions encountered RNAPII at each gene, perhaps by modulating the elongation rate to allow reconfiguration of accessory factor activity or availability.
2021-12-20 | GSE184954 | GEO