Coordinated regulation of RNA polymerase II pausing and elongation progression by PAF1

• DOI: 10.1126/sciadv.abm5504
• Publication Date: 2022-04-01T17:59:57Z
• Authors: Zhenning Wang; Aixia Song; Hao Xu; Shibin Hu; Bolin Tao; Linna Peng; Jingwen Wang; Jiabei Li; Jiali Yu; Li Wang; Ze Li; Xizi Chen; Mengyun Wang; Yayun Chi; Jiong Wu; Yanhui Xu; Hai Zheng; Fei Xavier Chen
• Keywords: 0303 health sciences; 03 medical and health sciences; Biomedicine and Life Sciences

Pleiotropic transcription regulator RNA polymerase II (Pol II)–associated factor 1 (PAF1) governs multiple transcriptional steps and the deposition of several epigenetic marks. However, it remains unclear how ultimate transcriptional outcome is determined by PAF1 and whether it relates to PAF1-controlled epigenetic marks. We use rapid degradation systems and reveal direct PAF1 functions in governing pausing partially by recruiting Integrator-PP2A (INTAC), in addition to ensuring elongation. Following acute PAF1 degradation, most destabilized polymerase undergoes effective release, which presumably relies on skewed balance between INTAC and P-TEFb, resulting in hyperphosphorylated substrates including SPT5. Impaired Pol II progression during elongation, along with altered pause release frequency, determines the final transcriptional outputs. Moreover, PAF1 degradation causes a cumulative decline in histone modifications. These epigenetic alterations in chromatin likely further influence the production of transcripts from PAF1 target genes.