Cross-regulome profiling of RNA polymerases highlights the regulatory role of polymerase III on mRNA transcription by maintaining local chromatin architecture [ATAC-seq]

Genome binding/occupancy profiling by high throughput sequencing | Expression profiling by high throughput sequencing | Other Mammalian nuclei contain Pol I, Pol II, and Pol III. However, to what extent and how they are cross-regulated remains elusive. Here, we performed orthogonal multi-omics profiling after acute degradation of the largest subunits of Pol I, Pol II, and Pol III, and showed that they mainly affect specific genes. In contrast, the loss of Pol I or Pol II causes few changes for other RNA polymerases and confirms those known. The changes of Pol II transcription after Pol III depletion are the largest among all the cross-regulatory types. Meta-analyses reveal that Pol III depletion increases nucleosome positioning, reduces the FACT complex occupancy, and perturbs Pol II elongation for nearby mRNA genes. Furthermore, the nucleosome positioning changes also underpinning the Pol II effects on Pol III-mediated tRNA transcription. Our results suggest that Pol III works together with Pol II to coordinate their transcription activities by maintaining local chromatin architecture. Overall design: We performed PRO-seq, ChAR-seq, ATAC-seq, and ChIP-seq to investigate the roles of various specialized subunits in transcription and post-transcriptional regulation. The V6.5 mouse ES (mES) cell line was used for all the high-throughput analyses. Degron mES cells were treated with 1 µg/ml Doxycycline for different hours refer to individual Series.