ARF alters PAF1 complex integrity to selectively repress oncogenic transcription programs upon p53 loss

In this study, we found that the ARF tumor suppressor directly binds the PAF1 subunit to block the assembly of PAF1 complex (PAF1c) and its interaction with RNAPII, thereby dampening PAF1c-dependent transcription in vitro and in cells. To investigate whether ARF regulates RNAPII and PAF1c occupancy at putative target genes identified through RNA-seq, we performed ChIP-seq (RNAPII, PAF1, and CTR9) in ARF (shARF) vs. control (shNT) knockdown MEFs. Our data show that loss of ARF increases RNAPII, PAF1, and CTR9 occupancy on upregulated genes, consistent with ARF-mediated gene-specific repression. Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for RNA polymerase subunit RPB3 and PAF1 complex subunits PAF1 and CTR9 in mouse embryonic fibroblasts.