title: Bromodomain-containing protein 4 (BRD4) regulates RNA polymerase II serine 2 phosphorylation in human CD4+ T cells.
abstract: 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 Ser-2-phosphorylated Pol II (Pol II Ser-2) 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 Ser-2, and reduced expression of lineage-specific genes in primary human CD4+ T cells. A large number of JQ1-disrupted BRD4 binding regions exhibited diacetylated 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.
authors.affiliation: Laboratory of Gene Regulation and Inflammation, SIgN (Singapore Immunology Network), A*STAR (Agency for Science, Technology and Research), Biopolis, Immunos 04-00, 8A Biomedical Grove, Singapore.
authors.forename: Weishi
authors.initials: W
authors.lastname: Zhang
authors.forename: Celine
authors.initials: C
authors.lastname: Prakash
authors.forename: Calvin
authors.initials: C
authors.lastname: Sum
authors.forename: Yue
authors.initials: Y
authors.lastname: Gong
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Li
authors.forename: Jeffrey J T
authors.initials: JJ
authors.lastname: Kwok
authors.forename: Nina
authors.initials: N
authors.lastname: Thiessen
authors.forename: Sven
authors.initials: S
authors.lastname: Pettersson
authors.forename: Steven J M
authors.initials: SJ
authors.lastname: Jones
authors.forename: Stefan
authors.initials: S
authors.lastname: Knapp
authors.forename: Henry
authors.initials: H
authors.lastname: Yang
authors.forename: Keh-Chuang
authors.initials: KC
authors.lastname: Chin
mesh_terms: D000107:Acetylation; D001665:Binding Sites; D015496:CD4-Positive T-Lymphocytes / Q000201:enzymology*; D018797:Cell Cycle Proteins; D019070:Cell Lineage; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics; D015894:Genome, Human / Q000235:genetics; D006367:HeLa Cells; D051548:Histone Acetyltransferases / Q000378:metabolism; D006655:Histone Deacetylases / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D008239:Lysine / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism*; D042925:Positive Transcriptional Elongation Factor B / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D021381:Protein Transport; D012319:RNA Polymerase II / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D000092468:Bromodomain Containing Proteins
chemical_list: D018797:Cell Cycle Proteins; D051548:Histone Acetyltransferases; D006655:Histone Deacetylases; D006657:Histones; D008239:Lysine; D009687:Nuclear Proteins; D010768:Phosphoserine; D042925:Positive Transcriptional Elongation Factor B; D012319:RNA Polymerase II; D014157:Transcription Factors; C441289:BRD4 protein, human; D000092468:Bromodomain Containing Proteins