Unravelling molecular mechanisms in transcription-coupled nucleotide excision repair

Abstract

The cellular response to transcription-blocking DNA lesions involves the stalling of elongating RNA Polymerase II (RNAPIIo) at the lesion as well as a global shutdown of transcription. The stalling of RNAPIIo at such lesions initiates the transcription-coupled nucleotide excision repair pathway (TCR) to efficiently remove the damage and restore transcription. The TCR proteins, CSB, CSA, and UVSSA, are essential for the repair of transcription-blocking DNA lesions, but how the interplay between these proteins targets the core repair machinery, including the TFIIH complex, to lesion stalled RNAPIIo remains largely unknown.

Here, we demonstrate a sequential and highly cooperative assembly of TCR proteins and unveil the mechanism for TFIIH recruitment to DNA damage-stalled RNAPIIo. Importantly, we identified the previously uncharacterized ELOF1 gene as a core TCR factor with an additional role in preventing DNA damage during DNA replication.