scholarly journals True Lies: The Double Life of the Nucleotide Excision Repair Factors in Transcription and DNA Repair

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Nicolas Le May ◽  
Jean-Marc Egly ◽  
Frédéric Coin

Nucleotide excision repair (NER) is a major DNA repair pathway in eukaryotic cells. NER removes structurally diverse lesions such as pyrimidine dimers, arising upon UV irradiation or bulky chemical adducts, arising upon exposure to carcinogens and some chemotherapeutic drugs. NER defects lead to three genetic disorders that result in predisposition to cancers, accelerated aging, neurological and developmental defects. During NER, more than 30 polypeptides cooperate to recognize, incise, and excise a damaged oligonucleotide from the genomic DNA. Recent papers reveal an additional and unexpected role for the NER factors. In the absence of a genotoxic attack, the promoters of RNA polymerases I- and II-dependent genes recruit XPA, XPC, XPG, and XPF to initiate gene expression. A model that includes the growth arrest and DNA damage 45αprotein (Gadd45α) and the NER factors, in order to maintain the promoter of active genes under a hypomethylated state, has been proposed but remains controversial. This paper focuses on the double life of the NER factors in DNA repair and transcription and describes the possible roles of these factors in the RNA synthesis process.

2015 ◽  
Vol 4 (3) ◽  
pp. 725-738 ◽  
Author(s):  
Mahsa Karbaschi ◽  
Salvador Macip ◽  
Vilas Mistry ◽  
Hussein H. K. Abbas ◽  
George J. Delinassios ◽  
...  

Classically, the nucleotide excision repair (NER) of cyclobutane pyrimidine dimers (CPD) is a lengthy process (t1/2 > 48 h).


1989 ◽  
Vol 9 (11) ◽  
pp. 4777-4788 ◽  
Author(s):  
M Baer ◽  
G B Sancar

DNA photolyases catalyze the light-dependent repair of pyrimidine dimers in DNA. The results of nucleotide sequence analysis and spectroscopic studies demonstrated that photolyases from Saccharomyces cerevisiae and Escherichia coli share 37% amino acid sequence homology and contain identical chromophores. Do the similarities between these two enzymes extend to their interactions with DNA containing pyrimidine dimers, or does the organization of DNA into nucleosomes in S. cerevisiae necessitate alternative or additional recognition determinants? To answer this question, we used chemical and enzymatic techniques to identify the contacts made on DNA by S. cerevisiae photolyase when it is bound to a pyrimidine dimer and compared these contacts with those made by E. coli photolyase and by a truncated derivative of the yeast enzyme when bound to the same substrate. We found evidence for a common set of interactions between the photolyases and specific phosphates in the backbones of both strands as well as for interactions with bases in both the major and minor grooves of dimer-containing DNA. Superimposed on this common pattern were significant differences in the contributions of specific contacts to the overall binding energy, in the interactions of the enzymes with groups on the complementary strand, and in the extent to which other DNA-binding proteins were excluded from the region around the dimer. These results provide strong evidence both for a conserved dimer-binding motif and for the evolution of new interactions that permit photolyases to also act as accessory proteins in nucleotide excision repair. The locations of the specific contacts made by the yeast enzyme indicate that the mechanism of nucleotide excision repair in this organism involves incision(s) at a distance from the pyrimidine dimer.


Biochemistry ◽  
2010 ◽  
Vol 49 (6) ◽  
pp. 1053-1055 ◽  
Author(s):  
Pawel Jaruga ◽  
Yan Xiao ◽  
Vladimir Vartanian ◽  
R. Stephen Lloyd ◽  
Miral Dizdaroglu

1992 ◽  
Vol 12 (7) ◽  
pp. 3041-3049
Author(s):  
L Bardwell ◽  
A J Cooper ◽  
E C Friedberg

The RAD1 and RAD10 genes of Saccharomyces cerevisiae are two of at least seven genes which are known to be required for damage-specific recognition and/or damage-specific incision of DNA during nucleotide excision repair. RAD1 and RAD10 are also involved in a specialized mitotic recombination pathway. We have previously reported the purification of the RAD10 protein to homogeneity (L. Bardwell, H. Burtscher, W. A. Weiss, C. M. Nicolet, and E. C. Friedberg, Biochemistry 29:3119-3126, 1990). In the present studies we show that the RAD1 protein, produced by in vitro transcription and translation of the cloned gene, specifically coimmunoprecipitates with the RAD10 protein translated in vitro or purified from yeast. Conversely, in vitro-translated RAD10 protein specifically coimmunoprecipitates with the RAD1 protein. The sites of this stable and specific interaction have been mapped to the C-terminal regions of both polypeptides. This portion of RAD10 protein is evolutionarily conserved. These results are the first biochemical evidence of a specific association between any eukaryotic proteins genetically identified as belonging to a recombination or DNA repair pathway and suggest that the RAD1 and RAD10 proteins act at the same or consecutive biochemical steps in both nucleotide excision repair and mitotic recombination.


1994 ◽  
Vol 14 (9) ◽  
pp. 6135-6142
Author(s):  
R Verhage ◽  
A M Zeeman ◽  
N de Groot ◽  
F Gleig ◽  
D D Bang ◽  
...  

The rad16 mutant of Saccharomyces cerevisiae was previously shown to be impaired in removal of UV-induced pyrimidine dimers from the silent mating-type loci (D. D. Bang, R. A. Verhage, N. Goosen, J. Brouwer, and P. van de Putte, Nucleic Acids Res. 20:3925-3931, 1992). Here we show that rad7 as well as rad7 rad16 double mutants have the same repair phenotype, indicating that the RAD7 and RAD16 gene products might operate in the same nucleotide excision repair subpathway. Dimer removal from the genome overall is essentially incomplete in these mutants, leaving about 20 to 30% of the DNA unrepaired. Repair analysis of the transcribed RPB2 gene shows that the nontranscribed strand is not repaired at all in rad7 and rad16 mutants, whereas the transcribed strand is repaired in these mutants at a fast rate similar to that in RAD+ cells. When the results obtained with the RPB2 gene can be generalized, the RAD7 and RAD16 proteins not only are essential for repair of silenced regions but also function in repair of nontranscribed strands of active genes in S. cerevisiae. The phenotype of rad7 and rad16 mutants closely resembles that of human xeroderma pigmentosum complementation group C (XP-C) cells, suggesting that RAD7 and RAD16 in S. cerevisiae function in the same pathway as the XPC gene in human cells. RAD4, which on the basis of sequence homology has been proposed to be the yeast XPC counterpart, seems to be involved in repair of both inactive and active yeast DNA, challenging the hypothesis that RAD4 and XPC are functional homologs.


2019 ◽  
Author(s):  
Goran Kokic ◽  
Aleksandar Chernev ◽  
Dimitry Tegunov ◽  
Christian Dienemann ◽  
Henning Urlaub ◽  
...  

AbstractGenomes are constantly threatened by DNA damage, but cells can remove a large variety of DNA lesions by nucleotide excision repair (NER)1. Mutations in NER factors compromise cellular fitness and cause human diseases such as Xeroderma pigmentosum (XP), Cockayne syndrome and trichothiodystrophy2,3. The NER machinery is built around the multisubunit transcription factor IIH (TFIIH), which opens the DNA repair bubble, scans for the lesion, and coordinates excision of the damaged DNA single strand fragment1,4. TFIIH consists of a kinase module and a core module that contains the ATPases XPB and XPD5. Here we prepare recombinant human TFIIH and show that XPB and XPD are stimulated by the additional NER factors XPA and XPG, respectively. We then determine the cryo-electron microscopy structure of the human core TFIIH-XPA-DNA complex at 3.6 Å resolution. The structure represents the lesion-scanning intermediate on the NER pathway and rationalizes the distinct phenotypes of disease mutations. It reveals that XPB and XPD bind double- and single-stranded DNA, respectively, consistent with their translocase and helicase activities. XPA forms a bridge between XPB and XPD, and retains the DNA at the 5’-edge of the repair bubble. Biochemical data and comparisons with prior structures6,7 explain how XPA and XPG can switch TFIIH from a transcription factor to a DNA repair factor. During transcription, the kinase module inhibits the repair helicase XPD8. For DNA repair, XPA dramatically rearranges the core TFIIH structure, which reorients the ATPases, releases the kinase module and displaces a ‘plug’ element from the DNA-binding pore in XPD. This enables XPD to move by ~80 Å, engage with DNA, and scan for the lesion in a XPG-stimulated manner. Our results provide the basis for a detailed mechanistic analysis of the NER mechanism.


2020 ◽  
Vol 15 (12) ◽  
pp. 3844-3878
Author(s):  
Sona Vodenkova ◽  
Amaya Azqueta ◽  
Andrew Collins ◽  
Maria Dusinska ◽  
Isabel Gaivão ◽  
...  

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1466 ◽  
Author(s):  
Barbara N. Borsos ◽  
Hajnalka Majoros ◽  
Tibor Pankotai

Nucleotide excision repair (NER) is a versatile DNA repair pathway which can be activated in response to a broad spectrum of UV-induced DNA damage, such as bulky adducts, including cyclobutane-pyrimidine dimers (CPDs) and 6–4 photoproducts (6–4PPs). Based on the genomic position of the lesion, two sub-pathways can be defined: (I) global genomic NER (GG-NER), involved in the ablation of damage throughout the whole genome regardless of the transcription activity of the damaged DNA locus, and (II) transcription-coupled NER (TC-NER), activated at DNA regions where RNAPII-mediated transcription takes place. These processes are tightly regulated by coordinated mechanisms, including post-translational modifications (PTMs). The fine-tuning modulation of the balance between the proteins, responsible for PTMs, is essential to maintain genome integrity and to prevent tumorigenesis. In this review, apart from the other substantial PTMs (SUMOylation, PARylation) related to NER, we principally focus on reversible ubiquitylation, which involves E3 ubiquitin ligase and deubiquitylase (DUB) enzymes responsible for the spatiotemporally precise regulation of NER.


2004 ◽  
Vol 24 (3) ◽  
pp. 1200-1205 ◽  
Author(s):  
Ming Tian ◽  
Reiko Shinkura ◽  
Nobuhiko Shinkura ◽  
Frederick W. Alt

ABSTRACT Xeroderma pigmentosum (XP) is a human genetic disease which is caused by defects in nucleotide excision repair. Since this repair pathway is responsible for removing UV irradiation-induced damage to DNA, XP patients are hypersensitive to sunlight and are prone to develop skin cancer. Based on the underlying genetic defect, the disease can be divided into the seven complementation groups XPA through XPG. XPF, in association with ERCC1, constitutes a structure-specific endonuclease that makes an incision 5′ to the photodamage. XPF-ERCC1 has also been implicated in both removal of interstrand DNA cross-links and homology-mediated recombination and in immunoglobulin class switch recombination (CSR). To study the function of XPF in vivo, we inactivated the XPF gene in mice. XPF-deficient mice showed a severe postnatal growth defect and died approximately 3 weeks after birth. Histological examination revealed that the liver of mutant animals contained abnormal cells with enlarged nuclei. Furthermore, embryonic fibroblasts defective in XPF are hypersensitive to UV irradiation and mitomycin C treatment. No defect in CSR was detected, suggesting that the nuclease is dispensable for this recombination process. These phenotypes are identical to those exhibited by the ERCC1-deficient mice, consistent with the functional association of the two proteins. The complex phenotype suggests that XPF-ERCC1 is involved in multiple DNA repair processes.


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