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

Wang, Zhenning; Song, Aixia; Xu, Hao; Hu, Shibin; Tao, Bolin; Peng, Linna; Wang, Jingwen; Li, Jiabei et al. · Sci Adv · 2022

basic_science · Level V

Where this comes from

Abstract

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.