Genomic structure, chromosomal localization and identification of mutations in the xeroderma pigmentosum variant (XPV) gene

Yuasa, Mayumi; Masutani, Chikahide; Eki, Toshihiko; Hanaoka, Fumio

doi:10.1038/sj.onc.1203842

Cited by 57 publications

(37 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We also report relocalization of pol in response to irradiation, suggesting that substrate availability plays a significant role in regulation of the error-prone activity of the polymerase. Information similar to that of parts of our study was recently published during the preparation of this report (Yamada et al, 2000;Yuasa et al, 2000;Kannouche et al, 2001), and we report our corresponding results in abbreviated form here for background to our additional novel results.…”

Section: Introductionmentioning

confidence: 54%

See 1 more Smart Citation

DNA polymerase η undergoes alternative splicing, protects against UV sensitivity and apoptosis, and suppresses Mre11‐dependent recombination

Thakur

Wernick

Collins

et al. 2001

Genes Chromosomes & Cancer

View full text Add to dashboard Cite

Polymerase eta (pol eta) is a low-fidelity DNA polymerase that is the product of the gene, POLH, associated with the human XP variant disorder in which there is an extremely high level of solar-induced skin carcinogenesis. The complete human genomic sequence spans about 40 kb containing 10 coding exons and a cDNA of 2.14 kb; exon I is untranslated and is 6 kb upstream from the first coding exon. Using bacterial artificial chromosomes (BACs), the gene was mapped to human chromosome band 6p21 and mouse band 17D. The gene is expressed in most tissues, except for very low or undetectable levels in peripheral lymphocytes, fetal spleen, and adult muscle; exon II, however, is frequently spliced out in normal cells and in almost half the transcripts in the testis and fetal liver. Expression of POLH in a multicopy episomal vector proved nonviable, suggesting that overexpression is toxic. Expression from chromosomally integrated linear copies using either an EF1-alpha or CMV promoter was functional, resulting in cell lines with low or high levels of pol eta protein, respectively. Point mutations in the center of the gene and in a C-terminal cysteine and deletion of exon II resulted in inactivation, but addition of a terminal 3 amino acid C-terminal tag, or an N- or C-terminal green fluorescent protein, had no effect on function. A low level of expression of pol eta eliminated hMre11 recombination and partially restored UV survival, but did not prevent UV-induced apoptosis, which required higher levels of expression. Polymerase eta is therefore involved in S-phase checkpoint and signal transduction pathways that lead to arrest in S, apoptosis, and recombination. In normal cells, the predominant mechanism of replication of UV damage involves pol eta-dependent bypass, and Mre11-dependent recombination that acts is a secondary, backup mechanism when cells are severely depleted of pol eta.

show abstract

Section: Introductionmentioning

confidence: 54%

“…The next day, filters were washed and exposed to film at Ϫ80°C for 2 days. Genomic clones were confirmed by PCR and mapped by FISH to 6p21, consistent with recent reports (Yuasa et al, 2000;Wood et al, 2001). …”

Section: Human Chromosome Locationmentioning

confidence: 72%

DNA polymerase η undergoes alternative splicing, protects against UV sensitivity and apoptosis, and suppresses Mre11‐dependent recombination

Thakur

Wernick

Collins

et al. 2001

Genes Chromosomes & Cancer

View full text Add to dashboard Cite

show abstract

“…This protein was expressed at reduced levels in Polh ϩ/Ϫ Poli ϩ/ϩ cells ( . In any case, this small Pol protein derived from the mutated Polh allele should be deficient in TLS activity, since it lacks an essential domain designated the polymerase-associated domain (PAD)/little finger domain/ wrist (4,37,56,61) and resembles the expected product (305 amino acids) of the mutated Polh allele of human XP2SA cells (5,74) (Fig. 2C).…”

Section: Resultsmentioning

confidence: 99%

UV-B Radiation Induces Epithelial Tumors in Mice Lacking DNA Polymerase η and Mesenchymal Tumors in Mice Deficient for DNA Polymerase ι

Ohkumo

Kondo

Yokoi

et al. 2006

Molecular and Cellular Biology

Self Cite

107

View full text Add to dashboard Cite

DNA polymerase(Pol ) is the product of the Polh gene, which is responsible for the group variant of xeroderma pigmentosum, a rare inherited recessive disease which is characterized by susceptibility to sunlightinduced skin cancer. We recently reported in a study of Polh mutant mice that Pol is involved in the somatic hypermutation of immunoglobulin genes, but the cancer predisposition of Polh ؊/؊ mice has not been examined until very recently. Another translesion synthesis polymerase, Pol , a Pol paralog encoded by the Poli gene, is naturally deficient in the 129 mouse strain, and the function of Pol is enigmatic. Here, we generated Polh Poli doubledeficient mice and compared the tumor susceptibility of them with Polh-or Poli-deficient animals under the same genetic background. While Pol deficiency does not influence the UV sensitivity of mouse fibroblasts irrespective of Polh genotype, Polh Poli double-deficient mice show slightly earlier onset of skin tumor formation. Intriguingly, histological diagnosis after chronic treatment with UV light reveals that Pol deficiency leads to the formation of mesenchymal tumors, such as sarcomas, that are not observed in Polh ؊/؊ mice. These results suggest the involvement of the Pol and Pol proteins in UV-induced skin carcinogenesis.

show abstract

“…In the variant form of XP (XPV), skin cancer susceptibility results from a mutation in the POLH gene (4,5). The human POLH gene, located on chromosome 6p21.1-6p12, consists of 11 exons, of which exon 1 is untranslated (4)(5)(6). POLH encodes DNA polymerase Ë (polË), a member of the Y family of specialised DNA polymerases, that also includes pol È, κ, and Rev1.…”

Section: Introductionmentioning

confidence: 99%

The human POLH gene is not mutated, and is expressed in a cohort of patients with basal or squamous cell carcinoma of the skin

Flanagan

Rafferty²,

O’Neill³

et al. 2007

Int J Mol Med

View full text Add to dashboard Cite

Abstract. Skin cancer, the most common cancer in the general population, is strongly associated with exposure to the ultraviolet component of sunlight. To investigate the relationship between DNA damage processing and skin tumour development, we determined the POLH status of a cohort of skin cancer patients. The human POLH gene encodes DNA polymerase Ë (polË), which normally carries out accurate translesion synthesis past the major UV-induced photoproduct, the dithymine cyclobutane dimer. In the absence of active polË in xeroderma pigmentosum variant (XPV) patients, mutations accumulate at sites of UV-induced DNA damage, providing the initiating step in skin carcinogenesis. Forty patients diagnosed with skin cancer were genotyped for polymorphisms in the POLH protein-coding sequence, using glycosylase-mediated polymorphism detection (GMPD) and direct DNA sequencing of POLH PCR products derived from white blood cell genomic DNA. All individuals carried the wild-type POLH sequence. No POLH mutations were identified in genomic DNA from skin tumours derived from 15 of these patients. As determined by RT-PCR, POLH mRNA was expressed in all normal and skin tumour tissue examined. PolË protein was also detectable by Western blotting, in two matched normal and skin tumour extracts. An alternatively spliced form of POLH mRNA, lacking exon 2, was more readily detected in skin tissue than in white blood cells from the same patient. Real-time PCR was used to quantify POLH expression in matched normal and skin tumour-derived mRNA from a series of patients diagnosed with either basal or squamous cell carcinoma. Compared to matched normal skin tissue from the same patient, 1 of 7 SCC, and 4 of 10 BCC tumours examined showed at least a 2-fold reduction in POLH expression, while 1 of 7 SCC, and 3 of 10 BCC tumours showed at least a 2-fold increase in POLH expression. Differences in gene expression, rather than sequence changes may be the main mechanism by which POLH status varies between normal and skin tumours in the population under investigation. Knowledge of the POLH status in skin tumours could contribute to an understanding of the role of this gene in the development of the most common cancer in the general population.

show abstract

Genomic structure, chromosomal localization and identification of mutations in the xeroderma pigmentosum variant (XPV) gene

Cited by 57 publications

References 38 publications

DNA polymerase η undergoes alternative splicing, protects against UV sensitivity and apoptosis, and suppresses Mre11‐dependent recombination

DNA polymerase η undergoes alternative splicing, protects against UV sensitivity and apoptosis, and suppresses Mre11‐dependent recombination

UV-B Radiation Induces Epithelial Tumors in Mice Lacking DNA Polymerase η and Mesenchymal Tumors in Mice Deficient for DNA Polymerase ι

The human POLH gene is not mutated, and is expressed in a cohort of patients with basal or squamous cell carcinoma of the skin

Contact Info

Product

Resources

About