Most trichothiodystrophy (TTD) patients present mutations in the xeroderma pigmentosum D (XPD) gene, coding for a subunit of the transcription/repair factor IIH (TFIIH) complex involved in nucleotide excision repair (NER) and transcription. After UV irradiation, most TTD/XPD patients are more severely affected in the NER of cyclobutane pyrimidine dimers (CPD) than of 6-4-photoproducts (6-4PP). ...

The elusive cell cycle– transcription link cientists have known for years that transcription is repressed as cells enter mitosis, yet the mechanistic bridge between the two processes has eluded detection. Now, Jian Chen, Beat Suter (McGill University, Montreal, Canada), and colleagues find that Xpd, a component of the general transcription factor complex, TFIIH, regulates another member of the ...

The X-ray repair cross-complementing group 1 (XRCC1) and xeroderma pigmentosum group D (XPD) genes are involved in base excision repair and nucleotide excision repair of DNA repair pathways, respectively. A growing body of evidence suggests that XRCC1 and XPD are important in environmentally induced cancers, and polymorphisms in both genes have been identified. To determine whether the XRCC1 (c...

Lung cancer is strongly associated with exposure to tobacco smoke (1–3). Mutations in the K-ras gene have been found in 20–35% of lung adenocarcinomas of smokers (4–8), compared with about 5–7% in those of nonsmokers (7, 8), suggesting that their formation may be associated with exposure to tobacco smoke carcinogens. DNA repair helps preserve the integrity of the cellular genome by repairing DN...

Lung cancer is strongly associated with exposure to tobacco smoke (1–3). Mutations in the K-ras gene have been found in 20–35% of lung adenocarcinomas of smokers (4–8), compared with about 5–7% in those of nonsmokers (7, 8), suggesting that their formation may be associated with exposure to tobacco smoke carcinogens. DNA repair helps preserve the integrity of the cellular genome by repairing DN...

Sunlight causes DNA damage, including bulky lesions that are removed effectively by the nucleotide-excision repair (NER) pathway. There are at least eight core NER proteins participating in the pathway, and genetic variations in their genes may alter NER functions. We hypothesized that some NER variants are associated with risk of cutaneous melanoma. In a hospital-based case-control study of 60...

DNA damage recognition by the nucleotide excision repair pathway requires an initial step identifying helical distortions in the DNA and a proofreading step verifying the presence of a lesion. This proofreading step is accomplished in eukaryotes by the TFIIH complex. The critical damage recognition component of TFIIH is the XPD protein, a DNA helicase that unwinds DNA and identifies the damage....

AIM In our study, we analyzed the allelic frequency of XPD Lys751Gln polymorphism of the XPD gene and the correlation between its variant alleles with colorectal cancer in patients and control groups. BACKGROUND Human cells are routinely exposed to mutagenic and carcinogenic aromatic amines via smoking, pollution areas and other sources. These chemicals can form DNA adducts in vivo and thus l...

The xeroderma pigmentosum group D (XPD) helicase is a subunit of transcription/DNA repair factor, transcription factor II H (TFIIH) that catalyzes the unwinding of a damaged DNA duplex during nucleotide excision repair. Apart from two canonical helicase domains, XPD is composed of a 4Fe-S cluster domain involved in DNA damage recognition and a module of uncharacterized function termed the "ARCH...