Transcription-coupled NER (TC-NER)
Species Homo sapiens
The preferential repair of UV-induced damage in transcribed strands of active genes is known as Transcription-coupled NER (TC-NER). Impairment of the ability for TC-NER results in the onset of a severe hereditary disorder called Cockayne's syndrome, an autosomal recessive disease characterized by hypersensitivity to UV light . Many types of helix distorting lesions can block the movement of elongating RNA Pol II leading to its stalling and subsequent triggering of repair mechanisms. The repair of DNA damage in active genes occurs much faster compared to the repair in non-transcribed genomic regions (via GG-NER). Also, the non-transcribed strand of the same gene is repaired at a similar rate as that of non-transcribed genomic regions.
The transcriptional responses to DNA damage in terms of stalling of Pol II, its displacement from the lesion site etc. are not well elucidated. The following annotation in GK provides an overall picture of TC-NER and will be updated as and when new insights are obtained about these crucial steps.
Locations in the PathwayBrowser
DNA Repair(Homo sapiens)