Transcription-coupled repair - mechanisms of action, regulation, and associated human disorders

The transcription-coupled repair (TCR) pathway resolves transcription-blocking DNA lesions to maintain cellular function and prevent transcriptional arrest. Stalled RNA polymerase II (RNAPII) triggers repair mechanisms, including RNAPII ubiquitination, which recruit UVSSA and TFIIH. Defects in TCR-associated genes cause disorders like Cockayne syndrome, UV-sensitive syndrome, xeroderma pigmentosum, and recently defined AMeDS. TCR safeguards transcription, linking its failure to neurodegeneration and disease phenotypes.