Novel functional interactions between nucleotide excision DNA repair proteins influencing the enzymatic activities of TFIIH, XPG, and ERCC1-XPF.
The multisubunit basal transcription factor IIH (TFIIH) has a dual involvement in nucleotide excision repair (NER) of a variety of DNA lesions, including UV-induced photoproducts, and RNA polymerase II transcription. In both processes, TFIIH is implicated with local DNA unwinding, which is attributed to its helicase subunits XPB and XPD. To further define the role of TFIIH in NER, functional interactions between TFIIH and other DNA repair proteins were analyzed. We show that the TFIIH-associated ATPase activity is stimulated by both XPA and the XPC-HR23B complex. However, while XPA promotes the ATPase activity specifically in the presence of damaged DNA, stimulation by XPC-HR23B is lesion independent. Furthermore, we reveal that TFIIH inhibits the structure-specific endonuclease activities of both XPG and ERCC1-XPF, responsible for the 3' and 5' incision in NER, respectively. The inhibition occurs in the absence of ATP and is reversed upon addition of ATP. These results point toward additional roles for TFIIH and ATP during NER distinct from a requirement for DNA unwinding in the regulation of the endonuclease activities of XPG and ERCC1-XPF.
Winkler
G S
GS
Department of Cell Biology and Genetics, Medical Genetics Center, Center of Biomedical Genetics, Erasmus University, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.
Sugasawa
K
K
Eker
A P
AP
de Laat
W L
WL
Hoeijmakers
J H
JH
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry; D000818:Animals; D002478:Cells, Cultured; D004249:DNA Damage; D004265:DNA Helicases / Q000737:chemistry / Q000378:metabolism*; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004720:Endonucleases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004789:Enzyme Activation; D006367:HeLa Cells; D006801:Humans; D006868:Hydrolysis; D051379:Mice; D009687:Nuclear Proteins; D011506:Proteins / Q000378:metabolism*; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D019473:Transcription Factors, TFII; D000099250:DNA Excision Repair Protein ERCC-5
D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate; D004265:DNA Helicases; D004268:DNA-Binding Proteins; D004720:Endonucleases; D009687:Nuclear Proteins; D011506:Proteins; D051758:Transcription Factor TFIIH; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D000099250:DNA Excision Repair Protein ERCC-5; C501002:Xpc protein, mouse; C086984:XPC protein, human; C071447:ERCC1 protein, human; C499360:Ercc1 protein, mouse