Project description:Bmi-1, Ring1B, H3K27me3, Ser2 Pol II, Ser 5 Pol II binding pattern in WT and Psip1 KO MEFs Menin occupancy is studied over Hox genes and several non-hox genes Bmi-1, Ring1B, H3K27me3, Ser2 Pol II, Ser 5 Pol II ChIPs from WT and Psip1 KO MEFs
Project description:Bmi-1, Ring1B, H3K27me3, Ser2 Pol II, Ser 5 Pol II binding pattern in WT and Psip1 KO MEFs Menin occupancy is studied over Hox genes and several non-hox genes
Project description:We have discovered distinctive protein interactomes for Ser2 and Ser5 phosphorylation of the C-terminal domain (CTD) of RNA Pol II. Calcium Homeostasis Endoplasmic reticulum (CHERP) was identified in our pulldown to directly interact with Ser2 phosphomarks on the CTD of Pol II. As Pol II is a chromatin-associated protein, we sought to identify genomic regions that CHERP, a Pol II binding protein, occupy through ChIP-seq analysis.
Project description:Transcriptional elongation by RNA polymerase II (Pol II) is regulated by positive transcription elongation factor b (P-TEFb) in association with Bromodomain-containing protein 4 (BRD4). We used genome-wide chromatin immunoprecipitation sequencing in primary human CD4+ T cells to reveal that BRD4 co-localizes with Ser2-phosphorylated Pol II (Pol II Ser2) at both enhancers and promoters of active genes. Disruption of bromodomain:histone acetylation interactions by JQ1, a small-molecule bromodomain inhibitor, resulted in decreased BRD4 binding, reduced Pol II Ser2, and reduced expression of lineage-specific genes in primary human CD4+ T cells. A large number of JQ1-disrupted BRD4 binding regions exhibited di-acetylated H4 (lysine-5 and -8) and H3K27 acetylation (H3K27ac), which correlated with the presence of histone acetyltransferases and deacetylases. Genes associated with BRD4/H3K27ac co-occupancy exhibited significantly higher activity than those associated with H3K27ac or BRD4 binding alone. Comparison of BRD4 binding in T cells and in human embryonic stem cells revealed that enhancer BRD4 binding sites were predominantly lineage-specific. Our findings suggest that BRD4-driven Pol II phosphorylation at serine 2 plays an important role in regulating lineage-specific gene transcription in human CD4+ T cells. Examination of BRD4, total Pol II, serine 2 phosphorylated Pol II and serine 5 phosphorylated Pol II binding in CD4+ T cells (with and without JQ1 treatment) and BRD4 binding in human embryonic stems cell; PolyA RNA expression in CD4+ T cells( with and without JQ1 treatment) using RNA-seq
Project description:Transcriptional elongation by RNA polymerase II (Pol II) is regulated by positive transcription elongation factor b (P-TEFb) in association with Bromodomain-containing protein 4 (BRD4). We used genome-wide chromatin immunoprecipitation sequencing in primary human CD4+ T cells to reveal that BRD4 co-localizes with Ser2-phosphorylated Pol II (Pol II Ser2) at both enhancers and promoters of active genes. Disruption of bromodomain:histone acetylation interactions by JQ1, a small-molecule bromodomain inhibitor, resulted in decreased BRD4 binding, reduced Pol II Ser2, and reduced expression of lineage-specific genes in primary human CD4+ T cells. A large number of JQ1-disrupted BRD4 binding regions exhibited di-acetylated H4 (lysine-5 and -8) and H3K27 acetylation (H3K27ac), which correlated with the presence of histone acetyltransferases and deacetylases. Genes associated with BRD4/H3K27ac co-occupancy exhibited significantly higher activity than those associated with H3K27ac or BRD4 binding alone. Comparison of BRD4 binding in T cells and in human embryonic stem cells revealed that enhancer BRD4 binding sites were predominantly lineage-specific. Our findings suggest that BRD4-driven Pol II phosphorylation at serine 2 plays an important role in regulating lineage-specific gene transcription in human CD4+ T cells.
Project description:We investigated whether RNA Pol II mediated transcription was altered in Carm1 KO compared to control KO tumor cells. We examined p-Ser2 CTD Pol II relative to total CTD Pol II using mammalian native elongating transcript sequencing (mNET-Seq) (Nojima et al., 2016). Inactivation of the Carm1 gene substantially increased the normalized read density of p-Ser2 CTD Pol II tags relative total Pol II tags. These data provide evidence for altered transcriptional regulation in Carm1 deficient cells.
Project description:We report whole genome chromatin immunoprecipitation followed by sequencing (ChIP-seq) of 3 different RNA Pol II CTD modifications in MCF-7 breast cancer cells treated with vehicle (UNTR) or the proteasome inhibitor MG132 for 4 (MG4H) or 24 (MG24H) hours. We find the non-phosphorylated form of RNA Pol II CTD accumulates at TSS of all expressed genes in proteasome inhibited cells, particularly after 24H of MG132 treatment. Proteasome inhibition enhances Ser5-P and Ser2-P binding at TSS of genes induced by MG132. We note that proteasome inhibition establishes unique Ser2-P 5’ to 3’ gene profiles at induced compared to repressed genes. Overall proteasome inhibition enhances RNA Pol II processivity and expression of gene networks relevant to breast cancer. The study provides a comprehensive resource of RNA Pol II binding in proteasome inhibited cells.
Project description:Genome-wide studies have identified abundant small, non-coding RNAs including snRNAs, snoRNAs, cryptic unstable transcripts (CUTs), and upstream regulatory RNAs (uRNAs) that are transcribed by RNA polymerase II (pol II) and terminated by a Nrd1-dependent pathway. Here, we show that the prolyl isomerase, Ess1, is required for Nrd1-dependent termination of ncRNAs. Ess1 binds the carboxy terminal domain (CTD) of pol II and is thought to regulate transcription by conformational isomerization of Ser-Pro bonds within the CTD. In ess1 mutants, expression of ~10% of the genome was altered, due primarily to defects in termination of snoRNAs, CUTs, SUTs and uRNAs. Ess1 promoted dephosphorylation of Ser5 (but not Ser2) within the CTD, most likely by the Ssu72 phosphatase, and we provide evidence for a competition between Nrd1 and Pcf11 for CTD-binding that is regulated by Ess1-dependent isomerization. This is the first example of a prolyl isomerase required for interpreting the “CTD code.”
Project description:Eukaryotic RNA polymerase II (Pol II) has evolved an array of heptad repeats with the consensus sequence Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7 at the carboxy-terminal domain (CTD) of the large subunit (Rpb1). Differential phosphorylation of Ser2, Ser5, and Ser7 in the 5’ and 3’ regions of genes coordinates the binding of transcription and RNA processing factors to the initiating and elongating polymerase complexes. Here, we report phosphorylation of Thr4 by Polo-like-kinase-3 in mammalian cells. ChIPseq analyses indicate an increase of Thr4-P levels in the 3’ region of genes occurring subsequently to an increase of Ser2-P levels. A Thr4/Ala mutant of Pol II displays a lethal phenotype. This mutant reveals a global defect in RNA elongation, while initiation is largely unaffected. Since Thr4 replacement mutants are viable in yeast we conclude that this amino acid has evolved an essential function(s) in the CTD of Pol II for gene transcription in mammalian cells.