PAF1 regulation of promoter-proximal pause release via enhancer activation

Gene expression in metazoans is regulated by RNA Polymerase II (Pol II) promoter-proximal pausing and its release. Previously, we identified that Pol II-associated factor 1 (PAF1) modulates the release of paused Pol II into productive elongation. Here, we find that PAF1 occupies transcriptional enhancers and restrains hyperactivation of a subset of these enhancers. Enhancer activation as the result of Paf1 loss releases Pol II from paused promoters of nearby PAF1 target genes. Knockout of PAF1-regulated enhancers attenuates the release of paused Pol II on PAF1 target genes without major interference in the establishment of pausing at their cognate promoters. Thus, a subset of enhancers can primarily modulate gene expression by controlling the release of paused Pol II in a PAF1-dependent manner. Overall design: ChIP-seq and different types of RNA-seq in in human cell lines targeted by PAF1 or scramble shRNA or ChIP-seq in cells depleted for PAF1 using the auxin-inducible degron system.