DNA damage-induced transcription stress triggers the genome-wide degradation of promoter-bound Pol II

DNA damage inhibits elongating RNA polymerase II, but also initiates genome-wide transcriptional responses. Here the authors reveal that particularly promoter-bound Pol II is degraded upon DNA damage in a GSK3 signaling-mediated response. The precise regulation of RNA Polymerase II (Pol II) transcription after genotoxic stress is crucial for proper execution of the DNA damage-induced stress response. While stalling of Pol II on transcription-blocking lesions (TBLs) blocks transcript elongation and initiates DNA repair in cis, TBLs additionally elicit a response in trans that regulates transcription genome-wide. Here we uncover that, after an initial elongation block in cis, TBLs trigger the genome-wide VCP-mediated proteasomal degradation of promoter-bound, P-Ser5-modified Pol II in trans. This degradation is mechanistically distinct from processing of TBL-stalled Pol II, is signaled via GSK3, and contributes to the TBL-induced transcription block, even in transcription-coupled repair-deficient cells. Thus, our data reveal the targeted degradation of promoter-bound Pol II as a critical pathway that allows cells to cope with DNA damage-induced transcription stress and enables the genome-wide adaptation of transcription to genotoxic stress.

Automated summary

DNA damage inhibits RNA polymerase II from elongating, but also triggers genome-wide transcriptional responses. Particularly, promoter-bound Pol II is degraded in a GSK3 signaling-mediated response, which is crucial for cells to cope with DNA damage-induced transcription stress.