Catalytic-dependent and independent functions of the histone acetyltransferase CBP promote pioneer factor-mediated zygotic genome activation [ChIP-seq]

Immediately after fertilization the genome is transcriptionally quiescent. Maternally encoded pioneer transcription factors reprogram the chromatin state and facilitate the transcription of the zygotic genome. In Drosophila, transcription is initiated by the pioneer factor Zelda. While Zelda-occupied sites are enriched with histone acetylation, a post-translational mark associated with active cis-regulatory regions, the functional relationship between Zelda and histone acetylation in zygotic genome activation remained unclear. We show that Zelda-mediated recruitment of the histone acetyltransferase CBP is essential for zygotic transcription and embryonic development. CBP catalytic activity is necessary for release of RNA Polymerase II (Pol II) into transcription elongation. However, CBP largely activates zygotic transcription independent of acetylation through Pol II recruitment. Neither acetylation nor CBP are required for the pioneering function of Zelda. Our data suggest that pioneer factor-mediated recruitment of CBP is a conserved mechanism required to activate zygotic transcription but that this role is separable from the function of pioneer factors in restructuring chromatin accessibility. Overall design: This data set contains data for ChIP-seq experiments in stage 5 embryos or S2 cells. ChIP-seq in embryos was done using antibodies against Zld and GFP to identify Zld and GFP-nej bound regions, respectively. ChIP-seq was also performed using an anti-H3K27ac antibody to identify regions acetylated by CBP. ChIP was performed in both wild-type and zld-RNAi genetic background to assay how binding of these factors are affected in the absence of Zld. In S2 cells, ChIP-seq for Zld was performed after induction of cells with CuSO4 through a copper inducible transgene. Cells were also treated with DMSO or a CBP catalytic inhibitor. H3K27ac ChIP-seq was also performed with the same treatments to verify inactivation of CBP after A485 treatment at Zld-bound sites. This data set contains ChIP-seq experiments in stage 5 Drosophila melanogaster embryos. ChIP-seq in embryos was done using an antibody against Zld to identify Zld bound regions. Zld ChIP-seq was performed on GFP-CBP;nos-deGrad/+;his2AV-RFP embryos to examine Zld binding upon loss of CBP and GFP-CBP;his2AV-RFP embryos were used as a control Additionally, Zld ChIP-seq was done on embryos with a zld-RNAi genetic background to ensure zld binding is depleted in the absence of Zld.