scholarly journals Nucleotide Excision Repair: From Molecular Defects to Neurological Abnormalities

2021 ◽  
Vol 22 (12) ◽  
pp. 6220
Author(s):  
Yuliya Krasikova ◽  
Nadejda Rechkunova ◽  
Olga Lavrik
Keyword(s):  
Mitochondrial Dysfunction ◽  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Genetic Disorders ◽  
Light Sensitivity ◽  
Dna Lesions ◽  
Specific Class ◽  
Dna Lesion ◽  
Nucleotide Excision ◽  
Low Efficiency

Nucleotide excision repair (NER) is the most versatile DNA repair pathway, which can remove diverse bulky DNA lesions destabilizing a DNA duplex. NER defects cause several autosomal recessive genetic disorders. Xeroderma pigmentosum (XP) is one of the NER-associated syndromes characterized by low efficiency of the removal of bulky DNA adducts generated by ultraviolet radiation. XP patients have extremely high ultraviolet-light sensitivity of sun-exposed tissues, often resulting in multiple skin and eye cancers. Some XP patients develop characteristic neurodegeneration that is believed to derive from their inability to repair neuronal DNA damaged by endogenous metabolites. A specific class of oxidatively induced DNA lesions, 8,5′-cyclopurine-2′-deoxynucleosides, is considered endogenous DNA lesions mainly responsible for neurological problems in XP. Growing evidence suggests that XP is accompanied by defective mitophagy, as in primary mitochondrial disorders. Moreover, NER pathway is absent in mitochondria, implying that the mitochondrial dysfunction is secondary to nuclear NER defects. In this review, we discuss the current understanding of the NER molecular mechanism and focuses on the NER linkage with the neurological degeneration in patients with XP. We also present recent research advances regarding NER involvement in oxidative DNA lesion repair. Finally, we highlight how mitochondrial dysfunction may be associated with XP.

scholarly journals Mechanism of DNA Lesion Homing and Recognition by the Uvr Nucleotide Excision Repair System

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Seung-Joo Lee ◽  
Rou-Jia Sung ◽  
Gregory L. Verdine
Keyword(s):  
Dna Repair ◽  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Dna Lesions ◽  
Repair System ◽  
Genome Maintenance ◽  
Dna Lesion ◽  
Nucleotide Excision ◽  
Biochemical Studies ◽  
Lesion Recognition

Nucleotide excision repair (NER) is an essential DNA repair system distinguished from other such systems by its extraordinary versatility. NER removes a wide variety of structurally dissimilar lesions having only their bulkiness in common. NER can also repair several less bulky nucleobase lesions, such as 8-oxoguanine. Thus, how a single DNA repair system distinguishes such a diverse array of structurally divergent lesions from undamaged DNA has been one of the great unsolved mysteries in the field of genome maintenance. Here we employ a synthetic crystallography approach to obtain crystal structures of the pivotal NER enzyme UvrB in complex with duplex DNA, trapped at the stage of lesion-recognition. These structures coupled with biochemical studies suggest that UvrB integrates the ATPase-dependent helicase/translocase and lesion-recognition activities. Our work also conclusively establishes the identity of the lesion-containing strand and provides a compelling insight to how UvrB recognizes a diverse array of DNA lesions.

scholarly journals Poly(ADP-ribose) polymerase 1 escorts XPC to UV-induced DNA lesions during nucleotide excision repair

2017 ◽  
Vol 114 (33) ◽  
pp. E6847-E6856 ◽  
Author(s):  
Mihaela Robu ◽  
Rashmi G. Shah ◽  
Nupur K. Purohit ◽  
Pengbo Zhou ◽  
Hanspeter Naegeli ◽  
...  
Keyword(s):  
Steady State ◽  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Dna Lesions ◽  
Stable Complex ◽  
Lesion Site ◽  
Genomic Context ◽  
Dna Lesion ◽  
Nucleotide Excision ◽  
Damaged Dna

Xeroderma pigmentosum C (XPC) protein initiates the global genomic subpathway of nucleotide excision repair (GG-NER) for removal of UV-induced direct photolesions from genomic DNA. The XPC has an inherent capacity to identify and stabilize at the DNA lesion sites, and this function is facilitated in the genomic context by UV-damaged DNA-binding protein 2 (DDB2), which is part of a multiprotein UV–DDB ubiquitin ligase complex. The nuclear enzyme poly(ADP-ribose) polymerase 1 (PARP1) has been shown to facilitate the lesion recognition step of GG-NER via its interaction with DDB2 at the lesion site. Here, we show that PARP1 plays an additional DDB2-independent direct role in recruitment and stabilization of XPC at the UV-induced DNA lesions to promote GG-NER. It forms a stable complex with XPC in the nucleoplasm under steady-state conditions before irradiation and rapidly escorts it to the damaged DNA after UV irradiation in a DDB2-independent manner. The catalytic activity of PARP1 is not required for the initial complex formation with XPC in the nucleoplasm but it enhances the recruitment of XPC to the DNA lesion site after irradiation. Using purified proteins, we also show that the PARP1–XPC complex facilitates the handover of XPC to the UV-lesion site in the presence of the UV–DDB ligase complex. Thus, the lesion search function of XPC in the genomic context is controlled by XPC itself, DDB2, and PARP1. Our results reveal a paradigm that the known interaction of many proteins with PARP1 under steady-state conditions could have functional significance for these proteins.

scholarly journals Structural basis of TFIIH activation for nucleotide excision repair

2019 ◽  
Author(s):  
Goran Kokic ◽  
Aleksandar Chernev ◽  
Dimitry Tegunov ◽  
Christian Dienemann ◽  
Henning Urlaub ◽  
...  
Keyword(s):  
Dna Repair ◽  
Transcription Factor ◽  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Dna Lesions ◽  
Structural Basis ◽  
Disease Mutations ◽  
Mechanistic Analysis ◽  
Nucleotide Excision ◽  
Dna Complex

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.

scholarly journals Histone H4 H75E mutation attenuates global genomic and Rad26-independent transcription-coupled nucleotide excision repair

2019 ◽  
Vol 47 (14) ◽  
pp. 7392-7401 ◽  
Author(s):  
Kathiresan Selvam ◽  
Sheikh Arafatur Rahman ◽  
Shisheng Li
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Histone H3 ◽  
Chromatin Accessibility ◽  
Dna Lesions ◽  
Histone H4 ◽  
Uv Sensitivity ◽  
Nucleotide Excision ◽  
Histone Octamers ◽  
Dna Silencing

Abstract Nucleotide excision repair (NER) consists of global genomic NER (GG-NER) and transcription coupled NER (TC-NER) subpathways. In eukaryotic cells, genomic DNA is wrapped around histone octamers (an H3–H4 tetramer and two H2A–H2B dimers) to form nucleosomes, which are well known to profoundly inhibit the access of NER proteins. Through unbiased screening of histone H4 residues in the nucleosomal LRS (loss of ribosomal DNA-silencing) domain, we identified 24 mutations that enhance or decrease UV sensitivity of Saccharomyces cerevisiae cells. The histone H4 H75E mutation, which is largely embedded in the nucleosome and interacts with histone H2B, significantly attenuates GG-NER and Rad26-independent TC-NER but does not affect TC-NER in the presence of Rad26. All the other histone H4 mutations, except for T73F and T73Y that mildly attenuate GG-NER, do not substantially affect GG-NER or TC-NER. The attenuation of GG-NER and Rad26-independent TC-NER by the H4H75E mutation is not due to decreased chromatin accessibility, impaired methylation of histone H3 K79 that is at the center of the LRS domain, or lowered expression of NER proteins. Instead, the attenuation is at least in part due to impaired recruitment of Rad4, the key lesion recognition and verification protein, to chromatin following induction of DNA lesions.

scholarly journals Photoprotective Role of Photolyase-Interacting RAD23 and Its Pleiotropic Effect on the Insect-Pathogenic Fungus Beauveria bassiana

2020 ◽  
Vol 86 (11) ◽  
Author(s):  
Ding-Yi Wang ◽  
Ya-Ni Mou ◽  
Sen-Miao Tong ◽  
Sheng-Hua Ying ◽  
Ming-Guang Feng
Keyword(s):  
Visible Light ◽  
Nucleotide Excision Repair ◽  
Radial Growth ◽  
Essential Role ◽  
Excision Repair ◽  
Pathogenic Fungus ◽  
Dna Lesions ◽  
Content Type ◽  
Multiple Stress ◽  
Nucleotide Excision

ABSTRACT RAD23 can repair yeast DNA lesions through nucleotide excision repair (NER), a mechanism that is dependent on proteasome activity and ubiquitin chains but different from photolyase-depending photorepair of UV-induced DNA damages. However, this accessory NER protein remains functionally unknown in filamentous fungi. In this study, orthologous RAD23 in Beauveria bassiana, an insect-pathogenic fungus that is a main source of fungal insecticides, was found to interact with the photolyase PHR2, enabling repair of DNA lesions by degradation of UVB-induced cytotoxic (6-4)-pyrimidine-pyrimidine photoproducts under visible light, and it hence plays an essential role in the photoreactivation of UVB-inactivated conidia but no role in reactivation of such conidia through NER in dark conditions. Fluorescence-labeled RAD23 was shown to normally localize in the cytoplasm, to migrate to vacuoles in the absence of carbon, nitrogen, or both, and to enter nuclei under various stresses, which include UVB, a harmful wavelength of sunlight. Deletion of the rad23 gene resulted in an 84% decrease in conidial UVB resistance, a 95% reduction in photoreactivation rate of UVB-inactivated conidia, and a drastic repression of phr2. A yeast two-hybrid assay revealed a positive RAD23-PHR2 interaction. Overexpression of phr2 in the Δrad23 mutant largely mitigated the severe defect of the Δrad23 mutant in photoreactivation. Also, the deletion mutant was severely compromised in radial growth, conidiation, conidial quality, virulence, multiple stress tolerance, and transcriptional expression of many phenotype-related genes. These findings unveil not only the pleiotropic effects of RAD23 in B. bassiana but also a novel RAD23-PHR2 interaction that is essential for the photoprotection of filamentous fungal cells from UVB damage. IMPORTANCE RAD23 is able to repair yeast DNA lesions through nucleotide excision in full darkness, a mechanism distinct from photolyase-dependent photorepair of UV-induced DNA damage but functionally unknown in filamentous fungi. Our study unveils that the RAD23 ortholog in a filamentous fungal insect pathogen varies in subcellular localization according to external cues, interacts with a photolyase required for photorepair of cytotoxic (6-4)-pyrimidine-pyrimidine photoproducts in UV-induced DNA lesions, and plays an essential role in conidial UVB resistance and reactivation of UVB-inactivated conidia under visible light rather than in the dark, as required for nucleotide excision repair. Loss-of-function mutations of RAD23 exert pleiotropic effects on radial growth, aerial conidiation, multiple stress responses, virulence, virulence-related cellular events, and phenotype-related gene expression. These findings highlight a novel mechanism underlying the photoreactivation of UVB-impaired fungal cells by RAD23 interacting with the photolyase, as well as its essentiality for filamentous fungal life.

O V A.4 Processing of structurally different DNA lesions by nucleotide excision repair

1997 ◽  
Vol 379 (1) ◽  
pp. S34
Author(s):  
Leon H.F. Mullenders ◽  
Anneke van Hoffen ◽  
Michiel Oosterwijk ◽  
Maaike Vreeswijk ◽  
Harry Vrieling ◽  
...  
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Dna Lesions ◽  
Nucleotide Excision

31 Effect of vitrification on global gene expression dynamics of bovine elongating embryos

2020 ◽  
Vol 32 (2) ◽  
pp. 141
Author(s):  
Z. Jiang ◽  
E. Gutierrez ◽  
H. Ming ◽  
B. Foster ◽  
L. Gatenby ◽  
...  
Keyword(s):  
Gene Expression ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Dysfunction ◽  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Cell Junction ◽  
Rna Seq ◽  
Protein Ubiquitination ◽  
Stage Of Development ◽  
Nucleotide Excision

The ability to cryopreserve gametes and embryos has been a valuable tool for reproductive management in all mammalian species, especially livestock. Embryo vitrification involves exposure to high concentrations of cryoprotectants and osmotic stress during cooling and warming. These factors have to affect gene expression. The elongating embryo is a stage of embryo development that can be recovered noninvasively in the cow on day (D) 14 and represents a critical stage of development when many embryos die. In this study, we aimed to evaluate the effect of vitrification on the transcriptome dynamics of D14 embryos by RNA sequencing (RNA-seq). Invitro blastocyst-stage embryos were vitrified by exposure to dimethyl sulfoxide and ethylene glycol solution, followed by placing on Cryo Loks and plunging in liquid nitrogen. After warming, embryos were loaded into straws and transferred into eight synchronized recipients, four cows received nonvitrified embryos and four cows received vitrified embryos (20 embryos per cow). Embryo flushing yielded 12 nonvitrified and 9 vitrified viable D14 embryos. Whole embryos (six nonvitrified and two vitrified embryos) or isolated trophectoderm (TE; four nonvitrified and seven vitrified) were processed for RNA-seq. The Smart-sEqn 2 protocol was followed to prepare RNA-seq libraries. Sequencing reads were prefiltered and aligned to the bovine genome, and gene expression values were calculated as fragments per kilobase of transcript per million mapped reads. Genes were deemed differentially expressed between treatments if they showed a false discovery rate P-value<0.05 and fold-change >2. Ingenuity pathway analysis was used to reveal gene ontology and pathways. Expression of 927 genes was changed in D14 embryos as a result of vitrification, with 782 and 145 genes upregulated and downregulated, respectively. In TE, vitrification resulted in 4096 and 280 upregulated or downregulated genes, respectively. Several pathways were upregulated by vitrification in both whole embryos and TE, including epithelial adherens junctions, sirtuin signalling, germ cell-Sertoli cell junction, ATM signalling, nucleotide excision repair, and protein ubiquitination pathways. Downregulated pathways included EIF2 signalling, oxidative phosphorylation, mitochondrial dysfunction, regulation of eIF4 and p70S6K signalling, mammalian target of rapamycin signalling, sirtuin singling, and nucleotide excision repair pathways. In addition, we found 671 and 61 genes upregulated and downregulated in both vitrified whole embryos and TE. Mitochondrial dysfunction and oxidative phosphorylation signalling were upregulated, whereas epithelial adherens junction and sirtuin signalling were downregulated, suggesting mitochondrial function and energy production were impaired in TE after vitrification. Our analysis identified specific pathways and implicated specific genes affected by cryopreservation and potentially affecting embryo developmental competence.

scholarly journals The TFIIH subunits p44/p62 act as a damage sensor during nucleotide excision repair

2020 ◽  
Vol 48 (22) ◽  
pp. 12689-12696
Author(s):  
Jamie T Barnett ◽  
Jochen Kuper ◽  
Wolfgang Koelmel ◽  
Caroline Kisker ◽  
Neil M Kad
Keyword(s):  
Dna Binding ◽  
Nucleotide Excision Repair ◽  
Single Molecule ◽  
Excision Repair ◽  
Active Role ◽  
Dna Lesions ◽  
Binding Studies ◽  
The Core ◽  
Nucleotide Excision ◽  
Direct Binding

Abstract Nucleotide excision repair (NER) in eukaryotes is orchestrated by the core form of the general transcription factor TFIIH, containing the helicases XPB, XPD and five ‘structural’ subunits, p62, p44, p34, p52 and p8. Recent cryo-EM structures show that p62 makes extensive contacts with p44 and in part occupies XPD’s DNA binding site. While p44 is known to regulate the helicase activity of XPD during NER, p62 is thought to be purely structural. Here, using helicase and adenosine triphosphatase assays we show that a complex containing p44 and p62 enhances XPD’s affinity for dsDNA 3-fold over p44 alone. Remarkably, the relative affinity is further increased to 60-fold by dsDNA damage. Direct binding studies show this preference derives from p44/p62’s high affinity (20 nM) for damaged ssDNA. Single molecule imaging of p44/p62 complexes without XPD reveals they bind to and randomly diffuse on DNA, however, in the presence of UV-induced DNA lesions these complexes stall. Combined with the analysis of a recent cryo-EM structure, we suggest that p44/p62 acts as a novel DNA-binding entity that enhances damage recognition in TFIIH. This revises our understanding of TFIIH and prompts investigation into the core subunits for an active role during DNA repair and/or transcription.

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