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GAGA factor, a positive regulator of global gene expression, modulates transcriptional pausing and organization of upstream nucleosomes.[ChIP-seq]

ABSTRACT: Promoter-proximal pausing of RNA polymerase II (RNA-Pol) is a rate-limiting step primed for rapid and synchronous induction of genes involved in critical physiological processes. Its underlying mechanisms are not fully understood. Using cytogenetic, genomic and genetic approaches, we provide evidence to support a direct role of a prevalent upstream GAGA binding factor (GAF) in transcriptional pausing of Hsp70 and many developmental regulators in Drosophila. For GAF target genes, the abundance of paused RNA-Pol and GAF is closely correlated. Promoters with higher GAF occupancy show stronger reduction of paused RNA-Pol in Gaf mutants. In addition, nucleosome organization is preferentially affected in the upstream region by GAF in a dosage-dependent manner. Genetic assays using a dominant eye phenotype caused by GAF overexpression suggests that GAF cooperates with nucleosome remodeler NURF, pausing factor NELF and an upstream binding factor BAB1. Thus, GAF plays a critical role in a regulatory network to facilitate transcriptional pausing through modulation of upstream nucleosomes.

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE70632 | GEO | 2016/07/19

SECONDARY ACCESSION(S): PRJNA289241

REPOSITORIES: GEO

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GAGA factor, a positive regulator of global gene expression, modulates transcriptional pausing and organization of upstream nucleosomes. [MNase-seq]

Project description:Promoter-proximal pausing of RNA polymerase II (RNA-Pol) is a rate-limiting step primed for rapid and synchronous induction of genes involved in critical physiological processes. Its underlying mechanisms are not fully understood. Using cytogenetic, genomic and genetic approaches, we provide evidence to support a direct role of a prevalent upstream GAGA binding factor (GAF) in transcriptional pausing of Hsp70 and many developmental regulators in Drosophila. For GAF target genes, the abundance of paused RNA-Pol and GAF is closely correlated. Promoters with higher GAF occupancy show stronger reduction of paused RNA-Pol in Gaf mutants. In addition, nucleosome organization is preferentially affected in the upstream region by GAF in a dosage-dependent manner. Genetic assays using a dominant eye phenotype caused by GAF overexpression suggests that GAF cooperates with nucleosome remodeler NURF, pausing factor NELF and an upstream binding factor BAB1. Thus, GAF plays a critical role in a regulatory network to facilitate transcriptional pausing through modulation of upstream nucleosomes.

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GAGA Factor maintains promoters in nucleosome-free conformation and allows promoter-proximal pausing [MNase]

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GAGA Factor maintains promoters in nucleosome-free conformation and allows promoter-proximal pausing [MNase]

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The Genomic Binding Profile of GAGA Element Associated Factor (GAF) in Drosophila S2 cells

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