麻豆传媒

Recruitment and functions of TFIIH in GG-NER. XPC binds to the damage site first. The interaction between XPC and TFIIH subunits p62 and XPB leads to the recruitment of TFIIH. XPA removes the CAK kinase module, which activates the helicase function of the TFIIH core complex to conduct DNA unwinding and damage verification. GG-NER, global genome NER; TFIIH, transcription factor IIH.

Recruitment and potential functions of TFIIH in TC-NER. The p62 subunit of TFIIH physically interacts with UVSSA and the interaction facilitates TFIIH recruitment to the damage-stalled RNA Pol II. Pol II ubiquitylation at Lys1268 enhances binding of TFIIH to Pol II. As DNA around the lesion is melted by RNA Pol II, the recruited TFIIH potentially extends the transcription bubble to generate a full-sized repair bubble. Similar to GG-NER, TFIIH may also verify the presence of a bulky lesion. However, it is unclear to what extent TC-NER requires TFIIH鈥檚 damage verification function, because RNA Pol II stalling may play a redundant role. Another potential role for TFIIH is to help Pol II backtracking or displacement. TC-NER, transcription-coupled NER; TFIIH, transcription factor IIH.