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Yu SL, Kang MS, Kim HY, Gorospe CM, Kim TS, Lee SK. The PCNA binding domain of Rad2p plays a role in mutagenesis by modulating the cell cycle in response to DNA damage. DNA Repair (Amst) 2014; 16:1-10. [PMID: 24674623 DOI: 10.1016/j.dnarep.2014.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 01/17/2014] [Accepted: 01/21/2014] [Indexed: 12/20/2022]
Abstract
The xeroderma pigmentosum group G (XPG) gene, encoding an essential element in nucleotide excision repair (NER), has a proliferating cell nuclear antigen-binding domain (PCNA-BD) at its C-terminal region. However, the role of this domain is controversial because its presence does not affect NER. Using yeast RAD2, a homolog of human XPG, we show that Rad2p interacts with PCNA through its PCNA-BD and the PCNA-BD of Rad2p plays a role in UV-induced mutagenesis. While a mutation of Rad2p endonuclease activity alone causes dramatically increased mutation rates and UV sensitivity, as well as growth retardation after UV irradiation, a mutation of the Rad2p PCNA-BD in the same mutant causes dramatically decreased mutation rates, reduced UV sensitivity and increased growth rate after UV irradiation. After UV irradiation, large-budded cells of Rad2p endonuclease defective mutants wane due to a mutation of the Rad2p PCNA-BD. Besides, the Rad2p PCNA-BD mutant protein exhibits alleviated PCNA-binding efficiency. These results show a hitherto unsuspected role of the Rad2p PCNA-BD that controls mutagenesis via cell cycle modulation together with PCNA. Furthermore, the high mutation rate of cells with other NER gene mutations was also decreased by the mutation of the Rad2p PCNA-BD, which indicates that the Rad2p-PCNA interaction might be responsible for mutagenesis control in the general NER pathway. Our results suggest that the drastically increased incidence of skin cancer in xeroderma pigmentosum patients could arise from the synergistic effects between cell cycle arrest due to the XPG-PCNA interaction and the accumulation of damaged DNA via defects in DNA damage repair.
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Affiliation(s)
- Sung-Lim Yu
- Inha Research Institute for Medical Sciences, College of Medicine, Inha University, Incheon 400-712, Republic of Korea
| | - Mi-Sun Kang
- Department of Pharmacology, College of Medicine, Inha University, Incheon 400-712, Republic of Korea
| | - Ho-Yeol Kim
- Department of Pharmacology, College of Medicine, Inha University, Incheon 400-712, Republic of Korea
| | - Choco Michael Gorospe
- Department of Molecular Biomedicine, College of Medicine, Inha University, Incheon 400-712, Republic of Korea
| | - Tong-Soo Kim
- Department of Parasitology, College of Medicine, Inha University, Incheon 400-712, Republic of Korea
| | - Sung-Keun Lee
- Department of Pharmacology, College of Medicine, Inha University, Incheon 400-712, Republic of Korea.
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2
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Restoration of proliferation ability with increased genomic instability from Rad2p-induced mitotic catastrophe in Saccharomyces cerevisiae. Mol Cell Toxicol 2011. [DOI: 10.1007/s13273-011-0026-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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3
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Kang MS, Yu SL, Lim HS, Choi B, Park CS, Kang JH, Lee SK. Mitotic catastrophe induced by overexpression of budding yeast Rad2p. Yeast 2010; 27:399-411. [PMID: 20222011 DOI: 10.1002/yea.1764] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Mitotic catastrophe provokes endopolyploidy, giant cell formation and, eventually, delayed cell death. Mitotic catastrophe is induced by defective cell cycle checkpoints and by some anticancer drugs, ionizing radiation and microtubule-destabilizing agents. RAD2 is a yeast homologue of XPG, which is a human endonuclease involved in nucleotide excision repair. Here we show that Rad2p overexpression alone, in the absence of extrinsic DNA damage, causes cell growth arrest and mitotic catastrophe. Interestingly, Rad2p-induced cell growth arrest is not caused by the catalytic activity of Rad2p but rather by its C-terminal region. Cells growth-arrested by Rad2p induction do not show apoptotic phenotypes and deletion of YCA1, a yeast caspase homologue, does not affect cell growth arrest by Rad2p induction. However, Rad2p-induced cell growth arrest is released by rad9 deletion but is not affected by downstream DNA damage checkpoint genes. These observations suggest that RAD2 has a function in coordinating cell cycle regulation and damaged DNA repair.
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Affiliation(s)
- Mi-Sun Kang
- Department of Pharmacology, Inha Research Institute for Medical Sciences, Incheon 400-712, Republic of Korea
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4
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Moritoh S, Miki D, Akiyama M, Kawahara M, Izawa T, Maki H, Shimamoto K. RNAi-mediated Silencing of OsGEN-L (OsGEN-like), a New Member of the RAD2/XPG Nuclease Family, Causes Male Sterility by Defect of Microspore Development in Rice. ACTA ACUST UNITED AC 2005; 46:699-715. [PMID: 15792960 DOI: 10.1093/pcp/pci090] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We have cloned a new member of the RAD2/XPG nuclease family, OsGEN-L (OsGEN-like), from rice (Oryza sativa L.). OsGEN-L possesses two domains, the N- and I-regions, that are conserved in the RAD2/XPG nuclease family. Database searches and phylogenetic analyses revealed that OsGEN-L belongs to class 4 of the RAD2/XPG nuclease family, and OsGEN-L homologs were found in animals and higher plants. To elucidate the function of OsGEN-L, we generated rice OsGEN-L-RNAi transgenic plants in which OsGEN-L expression was silenced. Most of the OsGEN-L-RNAi plants displayed low fertility, and some of them were male-sterile. OsGEN-L-RNAi plants lacked mature pollen, resulting from a defect in early microspore development. A OsGEN-L-green fluorescent protein (GFP) fusion protein was localized in the nucleus, and the OsGEN-L promoter was specifically active in the anthers. Furthermore, a recombinant OsGEN-L protein possessed flap endonuclease activity and both single-stranded and double-stranded DNA-binding activities. Our results suggest that OsGEN-L plays an essential role in DNA metabolism required for early microspore development in rice.
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Affiliation(s)
- Satoru Moritoh
- Laboratory of Plant Molecular Genetics, Nara Institute of Science and Technology, Takayama 8916-5, Ikoma, Nara, 630-0192 Japan
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5
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Emmert S, Slor H, Busch DB, Batko S, Albert RB, Coleman D, Khan SG, Abu-Libdeh B, DiGiovanna JJ, Cunningham BB, Lee MM, Crollick J, Inui H, Ueda T, Hedayati M, Grossman L, Shahlavi T, Cleaver JE, Kraemer KH. Relationship of neurologic degeneration to genotype in three xeroderma pigmentosum group G patients. J Invest Dermatol 2002; 118:972-82. [PMID: 12060391 DOI: 10.1046/j.1523-1747.2002.01782.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We studied three newly diagnosed xeroderma pigmentosum complementation group G patients with markedly different clinical features. An Israeli-Palestinian girl (XP96TA) had severe abnormalities suggestive of the xeroderma pigmentosum/Cockayne syndrome complex including sun sensitivity, neurologic and developmental impairment, and death by age 6 y. A Caucasian girl (XP82DC) also had severe sun sensitivity with neurologic and developmental impairment and died at 5.8 y. In contrast, a mildly affected 14-y-old Caucasian female (XP65BE) had sun sensitivity but no neurologic abnormalities. XP96TA, XP82DC, and XP65BE fibroblasts showed marked reductions in post-ultraviolet cell survival and DNA repair but these were higher in XP65BE than in XP82DC. XP96TA fibroblasts had very low XPG mRNA expression levels whereas XP65BE fibroblasts had nearly normal levels. Host cell reactivation of an ultraviolet-treated reporter assigned all three fibroblast strains to the rare xeroderma pigmentosum complementation group G (only 10 other patients previously reported). XP96TA and XP82DC cells had mutations in both XPG alleles that are predicted to result in severely truncated proteins including stop codons and two base frameshifts. The mild XP65BE patient had an early stop codon mutation in the paternal allele. The XP65BE maternal allele had a single base missense mutation (G2817A, Ala874Thr) that showed residual ability to complement xeroderma pigmentosum complementation group G cells. These observations agree with earlier studies demonstrating that XPG mutations, which are predicted to lead to severely truncated proteins in both alleles, were associated with severe xeroderma pigmentosum/Cockayne syndrome neurologic symptoms. Retaining residual functional activity in one allele was associated with mild clinical features without neurologic abnormalities.
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Affiliation(s)
- Steffen Emmert
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA
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6
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Fikus MU, Mieczkowski PA, Koprowski P, Rytka J, Sledziewska-Gójska E, Ciésla Z. The product of the DNA damage-inducible gene of Saccharomyces cerevisiae, DIN7, specifically functions in mitochondria. Genetics 2000; 154:73-81. [PMID: 10628970 PMCID: PMC1460913 DOI: 10.1093/genetics/154.1.73] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We reported previously that the product of the DNA damage-inducible gene of Saccharomyces cerevisiae, DIN7, belongs to a family of proteins that are involved in DNA repair and replication. The family includes S. cerevisiae proteins Rad2p and its human homolog XPGC, Rad27p and its mammalian homolog FEN-1, and Exonuclease I (Exo I). Here, we report that Din7p specifically affects metabolism of mitochondrial DNA (mtDNA). We have found that dun1 strains, defective in the transcriptional activation of the DNA damage-inducible genes RNR1, RNR2, and RNR3, exhibit an increased frequency in the formation of the mitochondrial petite (rho(-)) mutants. This high frequency of petites arising in the dun1 strains is significantly reduced by the din7::URA3 allele. On the other hand, overproduction of Din7p from the DIN7 gene placed under control of the GAL1 promoter dramatically increases the frequency of petite formation and the frequency of mitochondrial mutations conferring resistance to erythromycin (E(r)). The frequencies of chromosomal mutations conferring resistance to canavanine (Can(r)) or adenine prototrophy (Ade(+)) are not affected by enhanced synthesis of Din7p. Experiments using Din7p fused to the green fluorescent protein (GFP) and cell fractionation experiments indicate that the protein is located in mitochondria. A possible mechanism that may be responsible for the decreased stability of the mitochondrial genome in S. cerevisiae cells with elevated levels of Din7p is discussed.
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Affiliation(s)
- M U Fikus
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
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7
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Peng L, Rice MC, Kmiec EB. Analysis of the human RAD51L1 promoter region and its activation by UV light. Genomics 1998; 54:529-41. [PMID: 9878257 DOI: 10.1006/geno.1998.5536] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The human REC2/RAD51B gene (HGMW-approved symbol RAD51L1) encodes a 350-amino-acid protein with regional homologies to members of the RAD52 epistasis group. It is induced by DNA-damaging agents, and the overexpression of this gene product causes G1/S cell cycle arrest. In this report, the promoter region, containing the UV-responsive element, is revealed. Deletion analyses of a 1699-base fragment at the 5' end of the human REC2/RAD51B cDNA identified a 116-base sequence that appears to be responsible for radiation induction. This fragment contains many DNA sequences that have been identified in the promoter regions of other radiation-inducible genes in yeast and humans. Within this region are "consensus" binding sites for both the AP2 and the p53 proteins that may act to regulate the expression of the human REC2/RAD51B gene. Five putative transcripts have been identified from regions 5' of the promoter element that splice near the ATG translation start site. None of the transcripts contain the UV-inducible element nor the consensus transcription factor binding sites.
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Affiliation(s)
- L Peng
- Kimmel Cancer Center/Jefferson Center for Biomedical Research, Thomas Jefferson University, 700 East Butler Avenue, Doylestown, Pennsylvania, 18901-2697, USA
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8
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Hwang KY, Baek K, Kim HY, Cho Y. The crystal structure of flap endonuclease-1 from Methanococcus jannaschii. NATURE STRUCTURAL BIOLOGY 1998; 5:707-13. [PMID: 9699635 DOI: 10.1038/1406] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Flap endonuclease-1 (FEN-1), a structure specific nuclease, is an essential enzyme for eukaryotic DNA replication and repair. The crystal structure of FEN-1 from Methanococcus jannaschii, determined at 2.0 A resolution, reveals an active site with two metal ions residing on top of a deep cleft where several conserved acidic residues are clustered. Near the active site, a long flexible loop comprised of many basic and aromatic residues forms a hole large enough to accommodate the DNA substrate. Deletion mutations in this loop significantly decreased the nuclease activity and specificity of FEN-1, suggesting that the loop is critical for recognition and cleavage of the junction between single and double-stranded regions of flap DNA.
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Affiliation(s)
- K Y Hwang
- Structural Biology Center, Korea Institute of Science & Technology, Seoul, South Korea
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9
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Yu SL, Lee SK, Alexander H, Alexander S. Rapid changes of nucleotide excision repair gene expression following UV-irradiation and cisplatin treatment of Dictyostelium discoideum. Nucleic Acids Res 1998; 26:3397-403. [PMID: 9649625 PMCID: PMC147717 DOI: 10.1093/nar/26.14.3397] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Organisms use different mechanisms to detect and repair different types of DNA damage, and different species vary in their sensitivity to DNA damaging agents. The cellular slime mold Dictyostelium discoideum has long been recognized for its unusual resistance to UV and ionizing radiation. We have recently cloned three nucleotide excision repair (NER) genes from Dictyostelium , the rep B, D and E genes (the homologs of the human xeroderma pigmentosum group B, D and E genes, respectively). Each of these genes has a unique pattern of expression during the multicellular development of this organism. We have now examined the response of these genes to DNA damage. The rep B and D DNA helicase genes are rapidly and transiently induced in a dose dependent manner following exposure to both UV-light and the widely used chemotherapeutic agent cisplatin. Interestingly, the rep E mRNA level is repressed by UV but not by cisplatin, implying unique signal transduction pathways for recognizing and repairing different types of damage. Cells from all stages of growth and development display the same pattern of NER gene expression following exposure to UV-light. These results suggest that the response to UV is independent of DNA replication, and that all the factors necessary for rapid transcription of these NER genes are either stable throughout development, or are continuously synthesized. It is significant that the up-regulation of the rep B and D genes in response to UV and chemical damage has not been observed to occur in cells from other species. We suggest that this rapid expression of NER genes is at least in part responsible for the unusual resistance of Dictyostelium to DNA damage.
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Affiliation(s)
- S L Yu
- Division of Biological Sciences, 422 Tucker Hall, University of Missouri, Columbia, MO 65211-7400, USA
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10
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Qiu J, Guan MX, Bailis AM, Shen B. Saccharomyces cerevisiae exonuclease-1 plays a role in UV resistance that is distinct from nucleotide excision repair. Nucleic Acids Res 1998; 26:3077-83. [PMID: 9628902 PMCID: PMC147686 DOI: 10.1093/nar/26.13.3077] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Two closely related genes, EXO1 and DIN 7, in the budding yeast Saccharomyces cerevisiae have been found to be sequence homologs of the exo1 gene from the fission yeast Schizosaccharomyces pombe . The proteins encoded by these genes belong to the Rad2/XPG and Rad27/FEN-1 families, which are structure-specific nucleases functioning in DNA repair. An XPG nuclease deficiency in humans is one cause of xeroderma pigmentosum and those afflicted display a hypersensitivity to UV light. Deletion of the RAD2 gene in S. cerevisiae also causes UV hypersensitivity, due to a defect in nucleotide excision repair (NER), but residual UV resistance remains. In this report, we describe evidence for the residual repair of UV damage to DNA that is dependent upon Exo1 nuclease. Expression of the EXO1 gene is UV inducible. Genetic analysis indicates that the EXO1 gene is involved in a NER-independent pathway for UV repair, as exo1 rad2 double mutants are more sensitive to UV than either the rad2 or exo1 single mutants. Since the roles of EXO1 in mismatch repair and recombination have been established, double mutants were constructed to examine the possible relationship between the role of EXO1 in UV resistance and its roles in other pathways for repair of UV damaged DNA. The exo1 msh2 , exo1 rad51 , rad2 rad51 and rad2 msh2 double mutants were all more sensitive to UV than their respective pairs of single mutants. This suggests that the observed UV sensitivity of the exo1 deletion mutant is unlikely to be due to its functional deficiencies in MMR, recombination or NER. Further, it suggests that the EXO1 , RAD51 and MSH2 genes control independent mechanisms for the maintenance of UV resistance.
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Affiliation(s)
- J Qiu
- Department of Cell and Tumor Biology, The Beckman Research Institute of City of Hope, Duarte, CA 91010-3000, USA
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11
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Sweet DH, Jang YK, Sancar GB. Role of UME6 in transcriptional regulation of a DNA repair gene in Saccharomyces cerevisiae. Mol Cell Biol 1997; 17:6223-35. [PMID: 9343383 PMCID: PMC232473 DOI: 10.1128/mcb.17.11.6223] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In Saccharomyces cerevisiae UV radiation and a variety of chemical DNA-damaging agents induce the transcription of specific genes, including several involved in DNA repair. One of the best characterized of these genes is PHR1, which encodes the apoenzyme for DNA photolyase. Basal-level and damage-induced expression of PHR1 require an upstream activation sequence, UAS(PHR1), which has homology with DRC elements found upstream of at least 19 other DNA repair and DNA metabolism genes in yeast. Here we report the identification of the UME6 gene of S. cerevisiae as a regulator of UAS(PHR1) activity. Multiple copies of UME6 stimulate expression from UAS(PHR1) and the intact PHR1 gene. Surprisingly, the effect of deletion of UME6 is growth phase dependent. In wild-type cells PHR1 is induced in late exponential phase, concomitant with the initiation of glycogen accumulation that precedes the diauxic shift. Deletion of UME6 abolishes this induction, decreases the steady-state concentration of photolyase molecules and PHR1 mRNA, and increases the UV sensitivity of a rad2 mutant. Despite the fact that UAS(PHR1) does not contain the URS1 sequence, which has been previously implicated in UME6-mediated transcriptional regulation, we find that Ume6p binds to UAS(PHR1) with an affinity and a specificity similar to those seen for a URS1 site. Similar binding is also seen for DRC elements from RAD2, RAD7, and RAD53, suggesting that UME6 contributes to the regulated expression of a subset of damage-responsive genes in yeast.
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Affiliation(s)
- D H Sweet
- Department of Biochemistry and Biophysics, School of Medicine, The University of North Carolina at Chapel Hill, 27599-7260, USA
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12
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Herrlich P, Blattner C, Knebel A, Bender K, Rahmsdorf HJ. Nuclear and non-nuclear targets of genotoxic agents in the induction of gene expression. Shared principles in yeast, rodents, man and plants. Biol Chem 1997; 378:1217-29. [PMID: 9426181 DOI: 10.1515/bchm.1997.378.11.1217] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The interplay between environmental cues and the genetic response is decisive for the development, health and well-being of an organism. For some environmental factors a narrow margin separates beneficial and toxic impacts. With the increasing exposure to UV-B this dichotomy has reached public attention. This review will be concerned with the mechanisms that mediate a cellular genetic response to noxious agents. The toxic stimuli find access to the regulatory network inside cells by interacting at several points with cellular molecules - a process that converts the 'outside information' into 'cellular language'. As a consequence of such interactions, many adverse agents cause massive signal transduction and changes of gene expression. There is an interesting conservation of the mechanisms from yeast to man. An understanding of the genetic programs and of their phenotypic consequences is lagging behind.
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Affiliation(s)
- P Herrlich
- Forschungszentrum Karlsruhe, Institut für Genetik and Universität Karlsruhe, Germany
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13
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Park MS, Valdez J, Gurley L, Kim CY. Characterization of a putative helix-loop-helix motif in nucleotide excision repair endonuclease, XPG. J Biol Chem 1997; 272:27823-9. [PMID: 9346928 DOI: 10.1074/jbc.272.44.27823] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Complementation group G of xeroderma pigmentosum (XPG) is one of the most rare and pathophysiologically heterogeneous forms of this inherited disease. XPG patients exhibit varying phenotypes, from having a very mild defect in DNA repair to being severely affected, and a few cases are also associated with the neurological degeneracy and growth retardation of Cockayne's syndrome. The XPG gene encodes a 134-kDa nuclear protein that is essential for the incision steps of nucleotide excision repair. XPG protein contains a putative helix-loop-helix (HLH) motif in the region that is most conserved among the members of structure-specific endonuclease family. To establish the functional significance of the HLH motif, we used several approaches, including theoretical modeling, functional complementation assay, structure-specific endonuclease assay, and DNA binding assay. A secondary structure of the motif was predicted by energy minimization and the Monte Carlo simulation and empirically proven using the circular dichroism to contain a high content of alpha-helix. When an XPG mutant lacking the HLH was overexpressed in UV135 cells, which have defects in the hamster homolog of XPG, the mutant gene failed to confer to the hamster cells the resistance to UV light. A recombinant XPG protein lacking the HLH motif was purified from insect cells and tested for a structure-specific endonuclease activity. The mutant protein failed to cleave the flap strand. A recombinant peptide containing the HLH (amino acids 758-871) was expressed in and purified from bacteria, tested for DNA binding activity, and found to bind to a DNA substrate with the flap structure. These results suggest that the HLH motif is required for the catalytic and DNA binding activities of XPG.
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Affiliation(s)
- M S Park
- Life Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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14
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Clemente ML, Sartori G, Cardazzo B, Carignani G. Analysis of an 11.6 kb region from the right arm of chromosome VII of Saccharomyces cerevisiae between the RAD2 and the MES1 genes reveals the presence of three new genes. Yeast 1997; 13:287-90. [PMID: 9090059 DOI: 10.1002/(sici)1097-0061(19970315)13:3<287::aid-yea75>3.0.co;2-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Sequence analysis of an 11,628 bp DNA segment from the right arm of Saccharomyces cerevisiae chromosome VII revealed the presence of the 5' end of the RAD2 gene, the MES1 gene and six open reading frames (ORFs) each longer than 300 bp. Four of these ORFs are expressed genes, as indicated by transcript analysis. One of them, YGR261c, which specifies a putative beta-adaptine, corresponds to gene YKS5, which has recently been identified as a suppressor of loss of casein kinase 1 function. The remaining three ORFs are new genes; of these, YGR260w encodes a protein showing similarity to the S. cerevisiae allantoate permease and YGR262c specifies a putative protein kinase.
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Affiliation(s)
- M L Clemente
- Dipartimento di Chimica Biologica, Università di Padova, Italy
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15
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Habraken Y, Sung P, Prakash S, Prakash L. Transcription factor TFIIH and DNA endonuclease Rad2 constitute yeast nucleotide excision repair factor 3: implications for nucleotide excision repair and Cockayne syndrome. Proc Natl Acad Sci U S A 1996; 93:10718-22. [PMID: 8855246 PMCID: PMC38221 DOI: 10.1073/pnas.93.20.10718] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Nucleotide excision repair (NER) of ultraviolet light-damaged DNA in eukaryotes requires a large number of highly conserved protein factors. Recent studies in yeast have suggested that NER involves the action of distinct protein subassemblies at the damage site rather than the placement there of a "preformed repairosome" containing all the essential NER factors. Neither of the two endonucleases, Rad1-Rad10 and Rad2, required for dual incision, shows any affinity for ultraviolet-damaged DNA. Rad1-Rad10 forms a ternary complex with the DNA damage recognition protein Rad14, providing a means for targeting this nuclease to the damage site. It has remained unclear how the Rad2 nuclease is targeted to the DNA damage site and why mutations in the human RAD2 counterpart, XPG, result in Cockayne syndrome. Here we examine whether Rad2 is part of a higher order subassembly. Interestingly, we find copurification of Rad2 protein with TFIIH, such that TFIIH purified from a strain that overexpresses Rad2 contains a stoichiometric amount of Rad2. By several independent criteria, we establish that Rad2 is tightly associated with TFIIH, exhibiting an apparent dissociation constant < 3.3 x 10(-9) M. These results identify a novel subassembly consisting of TFIIH and Rad2, which we have designated as nucleotide excision repair factor 3. Association with TFIIH provides a means of targeting Rad2 to the damage site, where its endonuclease activity would mediate the 3' incision. Our findings are important for understanding the manner of assembly of the NER machinery and they have implications for Cockayne syndrome.
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Affiliation(s)
- Y Habraken
- Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston 77555-1061, USA
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16
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Nolan JP, Shen B, Park MS, Sklar LA. Kinetic analysis of human flap endonuclease-1 by flow cytometry. Biochemistry 1996; 35:11668-76. [PMID: 8794747 DOI: 10.1021/bi952840+] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Human flap endonuclease-1 (FEN-1) is a structure-specific endonuclease and exonuclease which is essential for DNA replication and repair. We have cloned a human FEN-1 gene, overexpressed it in Escherichia coli, purified the recombinant protein to near homogeneity, and characterized its cleavage of a flap DNA structure using a novel analytical approach based on flow cytometry. With this approach, we were able to measure continuously the kinetics of DNA cleavage by FEN-1 and to separate experimentally the binding and catalysis functions of the enzyme. When the reaction was initiated by the addition of FEN-1, the cleavage kinetics were dependent on enzyme concentration and appeared to saturate at high concentrations. When enzyme and substrate were preincubated in the presence of EDTA and the reaction initiated by the addition of Mg2+, rapid kinetic flow cytometry measurements showed that cleavage is fast (t1/2 approximately 6 s, k = 0.10 s-1). Using the single-turnover kinetics as a measure of the amount of enzyme-substrate complex present, we estimated the Kd for the FEN-1-flap DNA substrate to be 7.5 nM in the absence of Mg2+ and the rate constant for dissociation of the enzyme-substrate complex to be 0.07 s-1. Computer fitting of the experimental data to a kinetic model confirms these estimates for the individual steps and suggests some interesting features of enzymology using a surface-bound substrate.
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Affiliation(s)
- J P Nolan
- Life Sciences Division and National Flow Cytometry Resource, Los Alamos National Laboratory, New Mexico 87545, USA
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17
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Mueser TC, Nossal NG, Hyde CC. Structure of bacteriophage T4 RNase H, a 5' to 3' RNA-DNA and DNA-DNA exonuclease with sequence similarity to the RAD2 family of eukaryotic proteins. Cell 1996; 85:1101-12. [PMID: 8674116 DOI: 10.1016/s0092-8674(00)81310-0] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Bacteriophage T4 RNase H is a 5' to 3' exonuclease that removes RNA primers from the lagging strand of the DNA replication fork and is a member of the RAD2 family of eukaryotic and prokaryotic replication and repair nucleases. The crystal structure of the full-length native form of T4 RNase H has been solved at 2.06 angstroms resolution in the presence of Mg2+ but in the absence of nucleic acids. The most conserved residues are clustered together in a large cleft with two Mg2+ in the proposed active site. This structure suggests the way in which the widely separated conserved regions in the larger nucleotide excision repair proteins, such as human XPG, could assemble into a structure like that of the smaller replication nucleases.
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Affiliation(s)
- T C Mueser
- Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892-2755, USA
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18
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Sancar GB, Ferris R, Smith FW, Vandeberg B. Promoter elements of the PHR1 gene of Saccharomyces cerevisiae and their roles in the response to DNA damage. Nucleic Acids Res 1995; 23:4320-8. [PMID: 7501452 PMCID: PMC307386 DOI: 10.1093/nar/23.21.4320] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The PHR1 gene of Saccharomyces cerevisiae encodes the apoenzyme for the DNA repair enzyme photolyase. PHR1 transcription is induced in response to 254 nm radiation and a variety of chemical damaging agents. We report here the identification of promoter elements required for PHR1 expression. Transcription is regulated primarily through three sequence elements clustered within a 120 bp region immediately upstream of the translational start site. A 20 bp interrupted palindrome comprises UASPHR1 and is responsible for 80-90% of basal and induced expression. UASPHR1 alone can activate transcription of a CYC1 minimal promoter but does not confer damage responsiveness. In the intact PHR1 promoter UAS function is dependent upon an upstream essential sequence (UES). URSPHR1 contains a binding site for the damage-responsive repressor Prp; consistent with this role, deletion or specific mutations of the URS increase basal level expression and decrease the induction ratio. Deletion of URSPHR1 also eliminates the requirement for UESPHR1 for promoter activation, indicating that the UES attenuates Prp-mediated repression. Sequences within UASPHR1 are similar to regulatory sequences found upstream of both damage responsive and nonresponsive genes involved in DNA repair and metabolism.
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Affiliation(s)
- G B Sancar
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill 27599-7260, USA
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19
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Liefshitz B, Parket A, Maya R, Kupiec M. The role of DNA repair genes in recombination between repeated sequences in yeast. Genetics 1995; 140:1199-211. [PMID: 7498763 PMCID: PMC1206687 DOI: 10.1093/genetics/140.4.1199] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The presence of repeated sequences in the genome represents a potential source of karyotypic instability. Genetic control of recombination is thus important to preserve the integrity of the genome. To investigate the genetic control of recombination between repeated sequences, we have created a series of isogenic strains in which we could assess the role of genes involved in DNA repair in two types of recombination: direct repeat recombination and ectopic gene conversion. Naturally occurring (Ty elements) and artificially constructed repeats could be compared in the same cell population. We have found that direct repeat recombination and gene conversion have different genetic requirements. The role of the RAD51, RAD52, RAD54, RAD55, and RAD57 genes, which are involved in recombinational repair, was investigated. Based on the phenotypes of single and double mutants, these genes can be divided into three functional subgroups: one composed of RAD52, a second one composed of RAD51 and RAD54, and a third one that includes the RAD55 and RAD57 genes. Among seven genes involved in excision repair tested, only RAD1 and RAD10 played a role in the types of recombination studied. We did not detect a differential effect of any rad mutation on Ty elements as compared to artificially constructed repeats.
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Affiliation(s)
- B Liefshitz
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
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20
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Heude M, Chanet R, Fabre F. Regulation of the Saccharomyces cerevisiae Srs2 helicase during the mitotic cell cycle, meiosis and after irradiation. MOLECULAR & GENERAL GENETICS : MGG 1995; 248:59-68. [PMID: 7651328 DOI: 10.1007/bf02456614] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The expression of the SRS2 gene, which encodes a DNA helicase involved in DNA repair in Saccharomyces cerevisiae, was studied using an SRS2-lacZ fusion integrated at the chromosomal SRS2 locus. It is shown here that this gene is expressed at a low level and is tightly regulated. It is cell-cycle regulated, with induction probably being coordinated with that of the DNA-synthesis genes, which are transcribed at the G1-S boundary. It is also induced by DNA-damaging agents, but only during the G2 phase of the cell cycle; this distinguishes it from a number of other repair genes, which are inducible throughout the cycle. During meiosis, the expression of SRS2 rises at a time nearly coincident with commitment to recombination. Since srs2 null mutants are radiation sensitive essentially when treated in G1, the mitotic regulation pattern described here leads us to postulate that either secondary regulatory events limit Srs2 activity of G1 cells or Srs2 functions in a repair mechanism associated with replication.
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Affiliation(s)
- M Heude
- Institut Curie, Centre Universitaire, Orsay, France
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21
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Bang DD, Timmermans V, Verhage R, Zeeman AM, van de Putte P, Brouwer J. Regulation of the Saccharomyces cerevisiae DNA repair gene RAD16. Nucleic Acids Res 1995; 23:1679-85. [PMID: 7784171 PMCID: PMC306921 DOI: 10.1093/nar/23.10.1679] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The RAD16 gene product has been shown to be essential for the repair of the silenced mating type loci [Bang et al. (1992) Nucleic Acids Res. 20, 3925-3931]. More recently we demonstrated that the RAD16 and RAD7 proteins are also required for repair of non-transcribed strands of active genes in Saccharomyces cerevisiae [Waters et al. (1993) Mol. Gen. Genet. 239, 28-32]. We have studied the regulation of the RAD16 gene and found that the RAD16 transcript levels increased up to 7-fold upon UV irradiation. Heat shock at 42 degrees C also results in elevated levels of RAD16 mRNA. In sporulating MAT alpha/MATa diploid cells RAD16 mRNA is also induced. The basal level of the RAD16 transcript is constant during the mitotic cell cycle. G1-arrested cells show normal induction of RAD16 mRNA upon UV irradiation demonstrating that the induction is not a secondary consequence of G2 cell cycle arrest following UV irradiation. However, in cells arrested in G1 the induction of RAD16 mRNA after UV irradiation is not followed by a rapid decline as occurs in normal growing cells suggesting that the down regulation of RAD16 transcription is dependent on progression into the cell cycle.
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Affiliation(s)
- D D Bang
- Department of Biochemistry, Leiden Institute for Chemistry, Gorlaeus Laboratories, Leiden University, The Netherlands
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22
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Singh KK, Samson L. Replication protein A binds to regulatory elements in yeast DNA repair and DNA metabolism genes. Proc Natl Acad Sci U S A 1995; 92:4907-11. [PMID: 7761422 PMCID: PMC41816 DOI: 10.1073/pnas.92.11.4907] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Saccharomyces cerevisiae responds to DNA damage by arresting cell cycle progression (thereby preventing the replication and segregation of damaged chromosomes) and by inducing the expression of numerous genes, some of which are involved in DNA repair, DNA replication, and DNA metabolism. Induction of the S. cerevisiae 3-methyladenine DNA glycosylase repair gene (MAG) by DNA-damaging agents requires one upstream activating sequence (UAS) and two upstream repressing sequences (URS1 and URS2) in the MAG promoter. Sequences similar to the MAG URS elements are present in at least 11 other S. cerevisiae DNA repair and metabolism genes. Replication protein A (Rpa) is known as a single-stranded-DNA-binding protein that is involved in the initiation and elongation steps of DNA replication, nucleotide excision repair, and homologous recombination. We now show that the MAG URS1 and URS2 elements form similar double-stranded, sequence-specific, DNA-protein complexes and that both complexes contain Rpa. Moreover, Rpa appears to bind the MAG URS1-like elements found upstream of 11 other DNA repair and DNA metabolism genes. These results lead us to hypothesize that Rpa may be involved in the regulation of a number of DNA repair and DNA metabolism genes.
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Affiliation(s)
- K K Singh
- Department of Molecular and Cellular Toxicology, Harvard School of Public Health, Boston, MA 02115, USA
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23
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Sommers CH, Miller EJ, Dujon B, Prakash S, Prakash L. Conditional lethality of null mutations in RTH1 that encodes the yeast counterpart of a mammalian 5'- to 3'-exonuclease required for lagging strand DNA synthesis in reconstituted systems. J Biol Chem 1995; 270:4193-6. [PMID: 7876174 DOI: 10.1074/jbc.270.9.4193] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A 5'- to 3'-exonuclease of about 45 kDa has been purified from various mammalian sources and shown to be required for the completion of lagging strand synthesis in reconstituted DNA replication systems. RTH1 encodes the yeast Saccharomyces cerevisiae counterpart of the mammalian enzyme. To determine the in vivo biological role of RTH1-encoded 5'- to 3'-exonuclease, we have examined the effects of an rth1 delta mutation on various cellular processes. rth1 delta mutants grow poorly at 30 degrees C, and a cessation in growth occurs upon transfer of the mutant to 37 degrees C. At the restrictive temperature, the rth1 delta mutant exhibits a terminal cell cycle morphology similar to that of mutants defective in DNA replication, and levels of spontaneous mitotic recombination are elevated in the rth1 delta mutant even at the permissive temperature. The rth1 delta mutation does not affect UV or gamma-ray sensitivity but enhances sensitivity to the alkylating agent methyl methanesulfonate. The role of RTH1 in DNA replication and in repair of alkylation damage is discussed.
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Affiliation(s)
- C H Sommers
- Department of Biology, University of Rochester, New York 14642
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24
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Szankasi P, Smith GR. A role for exonuclease I from S. pombe in mutation avoidance and mismatch correction. Science 1995; 267:1166-9. [PMID: 7855597 DOI: 10.1126/science.7855597] [Citation(s) in RCA: 163] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Exonuclease I (Exo I) from Schizosaccharomyces pombe, a 5'-->3' double-stranded DNA exonuclease, is induced during meiotic prophase I. The exo1 gene is a member of a family of related DNA repair genes, including RAD2/rad13/xpgc and YKL510/rad2, conserved from yeast to humans. An exo1 mutant displays a mutator phenotype and alters activity of the ade6-M387 marker effect. These results suggest that Exo I acts in a pathway that corrects mismatched base pairs.
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Affiliation(s)
- P Szankasi
- Fred Hutchinson Cancer Research Center, Seattle, WA 98104
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25
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Affiliation(s)
- K S Sweder
- Department of Biological Sciences, Stanford University, CA 94305-5020, USA
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26
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Averbeck D, Averbeck S. Induction of the genes RAD54 and RNR2 by various DNA damaging agents in Saccharomyces cerevisiae. Mutat Res 1994; 315:123-38. [PMID: 7520995 DOI: 10.1016/0921-8777(94)90013-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The relationship between the induction of the genes RAD54 and RNR2 and the induction and repair of specific DNA lesions was studied in the yeast Saccharomyces cerevisiae using Rad54-lacZ and RNR2-lacZ fusion strains. Gene induction was followed by measuring beta-galactosidase activity. At comparable levels of furocoumarin-DNA photoadducts, RAD54 was more effectively induced by bifunctional than by monofunctional furocoumarins indicating that mixtures of monoadducts (MA) and interstrand cross-links (CL) provide a stronger inducing signal than MA. RNR2 induction kinetics were measured in relation to cell growth and survival responses after treatment with the furocoumarins 8-methoxypsoralen (8-MOP), 5-methoxypsoralen (5-MOP), 3-carbethoxypsoralen (3-CPs), 7-methyl-pyrido[3,4-c]psoralen (MePyPs) and 4,4',6-trimethylangelicin (TMA), benzo[a]pyrene (B(a)P and 1,6-dioxapyrene (1,6-DP) plus UVA, 254 nm UV radiation and cobalt-60 gamma-radiation. Induction of RNR2 took place during the DNA repair period before resumption of cell growth and clearly increased with increasing equitoxic dose levels. Treatments with furocoumarin plus 365 nm radiation (UVA) and 254 nm (UV) radiation were effective inducers whereas gene induction was relatively weak after gamma-radiation and absent after the induction of oxidative damage by B(a)P and 1,6-DP and UVA. The results suggest that it is the specific processing of different DNA lesions that determines the potency of the induction signal. Apparently, DNA lesions such as CL, and probably also closely located MA or pyrimidine dimers in opposite DNA strands involving the formation of double-strand breaks as repair intermediates, are most effective inducers.
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Affiliation(s)
- D Averbeck
- Institut Curie-Section de Biologie, URA 1292 CNRS, 26, Paris, France
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27
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Structural and functional conservation of the human homolog of the Schizosaccharomyces pombe rad2 gene, which is required for chromosome segregation and recovery from DNA damage. Mol Cell Biol 1994. [PMID: 8007985 DOI: 10.1128/mcb.14.7.4878] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The rad2 mutant of Schizosaccharomyces pombe is sensitive to UV irradiation and deficient in the repair of UV damage. In addition, it has a very high degree of chromosome loss and/or nondisjunction. We have cloned the rad2 gene and have shown it to be a member of the Saccharomyces cerevisiae RAD2/S. pombe rad13/human XPG family. Using degenerate PCR, we have cloned the human homolog of the rad2 gene. Human cDNA has 55% amino acid sequence identity to the rad2 gene and is able to complement the UV sensitivity of the rad2 null mutant. We have thus isolated a novel human gene which is likely to be involved both in controlling the fidelity of chromosome segregation and in the repair of UV-induced DNA damage. Its involvement in two fundamental processes for maintaining chromosomal integrity suggests that it is likely to be an important component of cancer avoidance mechanisms.
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28
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Murray JM, Tavassoli M, al-Harithy R, Sheldrick KS, Lehmann AR, Carr AM, Watts FZ. Structural and functional conservation of the human homolog of the Schizosaccharomyces pombe rad2 gene, which is required for chromosome segregation and recovery from DNA damage. Mol Cell Biol 1994; 14:4878-88. [PMID: 8007985 PMCID: PMC358860 DOI: 10.1128/mcb.14.7.4878-4888.1994] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The rad2 mutant of Schizosaccharomyces pombe is sensitive to UV irradiation and deficient in the repair of UV damage. In addition, it has a very high degree of chromosome loss and/or nondisjunction. We have cloned the rad2 gene and have shown it to be a member of the Saccharomyces cerevisiae RAD2/S. pombe rad13/human XPG family. Using degenerate PCR, we have cloned the human homolog of the rad2 gene. Human cDNA has 55% amino acid sequence identity to the rad2 gene and is able to complement the UV sensitivity of the rad2 null mutant. We have thus isolated a novel human gene which is likely to be involved both in controlling the fidelity of chromosome segregation and in the repair of UV-induced DNA damage. Its involvement in two fundamental processes for maintaining chromosomal integrity suggests that it is likely to be an important component of cancer avoidance mechanisms.
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Affiliation(s)
- J M Murray
- Department of Biochemistry, Sussex University, Falmer, United Kingdom
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29
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Shiomi T, Harada Y, Saito T, Shiomi N, Okuno Y, Yamaizumi M. An ERCC5 gene with homology to yeast RAD2 is involved in group G xeroderma pigmentosum. Mutat Res 1994; 314:167-75. [PMID: 7510366 DOI: 10.1016/0921-8777(94)90080-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We have isolated a human excision repair gene ERCC5 which complements the defect of the mouse UV-sensitive mutant XL216 (rodent complementation group 5). Here we report cDNA cloning of human and mouse ERCC5 genes using an exon containing an ERCC5 fragment as a probe. The ERCC5 cDNA encodes a predicted 133-kDa nuclear protein that shares some homology with the product of the yeast DNA repair gene RAD2. Transfection with mouse ERCC5 cDNA restored normal levels of UV resistance to XL216 cells. Microinjection of ERCC5 cDNA specifically restored the defect of xeroderma pigmentosum group G cells (XP-G) as measured by unscheduled DNA synthesis, and XP-G cells stably transformed with ERCC5 cDNA showed nearly normal UV resistance.
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Affiliation(s)
- T Shiomi
- Division of Genetics, National Institute of Radiological Sciences, Chiba, Japan
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30
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Guzder SN, Qiu H, Sommers CH, Sung P, Prakash L, Prakash S. DNA repair gene RAD3 of S. cerevisiae is essential for transcription by RNA polymerase II. Nature 1994; 367:91-4. [PMID: 8107780 DOI: 10.1038/367091a0] [Citation(s) in RCA: 118] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The RAD3 gene of Saccharomyces cerevisiae is required for excision repair of ultraviolet-damaged DNA and is essential for cell viability. The RAD3-encoded protein shares a high degree of homology with the human ERCC2(XPD) gene product. Mutations in XPD, besides causing the cancer-prone syndrome xeroderma pigmentosum, can also result in Cockayne's syndrome and trichothiodystrophy. To investigate the role of RAD3 in viability, we examined here the effect of a recessive, temperature-sensitive (ts) conditional lethal mutation of the gene on transcription by RNA polymerase II. Upon transfer to the restrictive temperature, the rad3-ts mutant rapidly ceases growth and poly(A)+ RNA synthesis is inhibited drastically. Messenger RNA levels of all the genes examined, HIS3, TRP3, STE2, MET19, RAD23, CDC7, CDC9 and ACT1, decline rapidly upon loss of RAD3 activity. The synthesis of heat-shock-inducible HSP26 mRNA and galactose-inducible GAL7 and GAL10 mRNAs is also drastically inhibited in the rad3-ts mutant at the restrictive temperature. The RNA polymerase II transcriptional activity in extract from the rad3-ts14 strain is thermolabile, and this in vitro transcriptional defect can be fully corrected by the addition of homogeneous RAD3 protein. These findings indicate that RAD3 protein has a direct and essential role in RNA polymerase II transcription.
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Affiliation(s)
- S N Guzder
- Department of Biology, University of Rochester, New York 14642
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31
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A common element involved in transcriptional regulation of two DNA alkylation repair genes (MAG and MGT1) of Saccharomyces cerevisiae. Mol Cell Biol 1994. [PMID: 8246943 DOI: 10.1128/mcb.13.12.7213] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Saccharomyces cerevisiae MAG gene encodes a 3-methyladenine DNA glycosylase that protects cells from killing by alkylating agents. MAG mRNA levels are induced not only by alkylating agents but also by DNA-damaging agents that do not produce alkylated DNA. We constructed a MAG-lacZ gene fusion to help identify the cis-acting promoter elements involved in regulating MAG expression. Deletion analysis defined the presence of one upstream activating sequence and one upstream repressing sequence (URS) and suggested the presence of a second URS. One of the MAG URS elements matches a decamer consensus sequence present in the promoters of 11 other S. cerevisiae DNA repair and metabolism genes, including the MGT1 gene, which encodes an O6-methylguanine DNA repair methyltransferase. Two proteins of 26 and 39 kDa bind specifically to the MAG and MGT1 URS elements. We suggest that the URS-binding proteins may play an important role in the coordinate regulation of these S. cerevisiae DNA repair genes.
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32
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Frankenberg-Schwager M, Frankenberg D, Harbich R. Radiation-induced mitotic gene conversion frequency in yeast is modulated by the conditions allowing DNA double-strand break repair. Mutat Res 1994; 314:57-66. [PMID: 7504192 DOI: 10.1016/0921-8777(94)90061-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Repair of DNA double-strand breaks (DSB) involves recombinational processes which may lead to gene conversion (intragenic recombination). Using the diploid yeast mutant rad54-3 heteroallelic for his1 (his1-7/his1-1) and temperature conditional for DSB rejoining, radiation induced gene conversion was investigated as dependent on DSB repair under different postirradiation conditions. Gene conversion is negligible under conditions preventing DSB repair (36 degrees C). In contrast, gene conversion is observed when cells are incubated at the permissive temperature (23 degrees C) both under growth and nongrowth conditions. However, there is a much higher yield of convertants for cells incubated under growth as opposed to nongrowth conditions. These results can most plausibly be explained by the cell cycle regulated enhancement of the expression of genes such as PMS and POL3 known to be involved in gene conversion processes and/or the enhanced recombination in transcriptionally active genes. 'Nutrient stress' inducible responses and/or cell cycle specific recombination pathways leading to gene conversion events preferentially in S-phase cells seem to be less likely.
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Affiliation(s)
- M Frankenberg-Schwager
- Abteilung Klinische Strahlenbiologie und Klinische Strahlenphysik, Universität Göttingen, Germany
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33
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Xiao W, Singh KK, Chen B, Samson L. A common element involved in transcriptional regulation of two DNA alkylation repair genes (MAG and MGT1) of Saccharomyces cerevisiae. Mol Cell Biol 1993; 13:7213-21. [PMID: 8246943 PMCID: PMC364791 DOI: 10.1128/mcb.13.12.7213-7221.1993] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The Saccharomyces cerevisiae MAG gene encodes a 3-methyladenine DNA glycosylase that protects cells from killing by alkylating agents. MAG mRNA levels are induced not only by alkylating agents but also by DNA-damaging agents that do not produce alkylated DNA. We constructed a MAG-lacZ gene fusion to help identify the cis-acting promoter elements involved in regulating MAG expression. Deletion analysis defined the presence of one upstream activating sequence and one upstream repressing sequence (URS) and suggested the presence of a second URS. One of the MAG URS elements matches a decamer consensus sequence present in the promoters of 11 other S. cerevisiae DNA repair and metabolism genes, including the MGT1 gene, which encodes an O6-methylguanine DNA repair methyltransferase. Two proteins of 26 and 39 kDa bind specifically to the MAG and MGT1 URS elements. We suggest that the URS-binding proteins may play an important role in the coordinate regulation of these S. cerevisiae DNA repair genes.
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Affiliation(s)
- W Xiao
- Department of Molecular and Cellular Toxicology, Harvard School of Public Health, Boston, Massachusetts 02115
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34
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Habraken Y, Sung P, Prakash L, Prakash S. Yeast excision repair gene RAD2 encodes a single-stranded DNA endonuclease. Nature 1993; 366:365-8. [PMID: 8247134 DOI: 10.1038/366365a0] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In eukaryotes nucleotide excision repair of DNA damaged by ultraviolet radiation requires several gene products; defects in this process result in the cancer-prone syndrome xeroderma pigmentosum (XP) in humans. The RAD2 gene is one of at least seven genes indispensable for excision repair in the yeast Saccharomyces cerevisiae, and its encoded protein shares remarkable homology with the XP group-G gene product. Here we overproduce the RAD2-encoded protein in S. cerevisiae, purify it to near homogeneity, and show that RAD2 protein in the presence of magnesium degrades circular single-stranded DNA. The RAD2 endonuclease is specific for single-stranded DNA as it does not act on double-stranded DNA. Given the absolute requirement for RAD2 in the incision step of excision repair, our findings directly implicate RAD2 protein and its human homologue XPG protein as a catalytic component that incises the damaged DNA strand during excision repair. Furthermore, our results indicate that eukaryotes probably employ two distinct endonuclease activities to mediate the dual incision at the damage site.
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Affiliation(s)
- Y Habraken
- Department of Biophysics, University of Rochester, New York 14642
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35
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Qiu H, Park E, Prakash L, Prakash S. The Saccharomyces cerevisiae DNA repair gene RAD25 is required for transcription by RNA polymerase II. Genes Dev 1993; 7:2161-71. [PMID: 7693549 DOI: 10.1101/gad.7.11.2161] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The RAD25 gene of Saccharomyces cerevisiae is required for excision repair of ultraviolet-damaged DNA and, in addition, is essential for viability. RAD25 shares a high degree of homology with the human ERCC3/XPBC-encoded protein, and the yeast and human proteins resemble one another in containing the conserved ATPase/DNA helicase sequence motifs. To determine the nature of the essential role of RAD25, we have isolated a recessive temperature-sensitive conditional lethal mutation of the gene and have examined its effect on transcription. Upon shift to the nonpermissive temperature, the rad25 temperature-sensitive (ts) mutant stops growth rapidly and shows a large decrease in the synthesis of poly(A)+ RNA. Transcription of a large number of yeast genes, including HIS3, TRP3, STE2, MET19, RAD23, CDC9, and ACT1 is inhibited at the restrictive temperature in the rad25 ts mutant, and the galactose-inducible synthesis of GAL7 and GAL10 mRNAs is also severely affected by the loss of RAD25 activity. These findings implicate a general requirement of RAD25 in RNA polymerase II transcription.
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Affiliation(s)
- H Qiu
- Department of Biology, University of Rochester, New York 14642
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36
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Human ERCC5 cDNA-cosmid complementation for excision repair and bipartite amino acid domains conserved with RAD proteins of Saccharomyces cerevisiae and Schizosaccharomyces pombe. Mol Cell Biol 1993. [PMID: 8413238 DOI: 10.1128/mcb.13.10.6393] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several human genes related to DNA excision repair (ER) have been isolated via ER cross-species complementation (ERCC) of UV-sensitive CHO cells. We have now isolated and characterized cDNAs for the human ERCC5 gene that complement CHO UV135 cells. The ERCC5 mRNA size is about 4.6 kb. Our available cDNA clones are partial length, and no single clone was active for UV135 complementation. When cDNAs were mixed pairwise with a cosmid clone containing an overlapping 5'-end segment of the ERCC5 gene, DNA transfer produced UV-resistant colonies with 60 to 95% correction of UV resistance relative to either a genomic ERCC5 DNA transformant or the CHO AA8 progenitor cells. cDNA-cosmid transformants regained intermediate levels (20 to 45%) of ER-dependent reactivation of a UV-damaged pSVCATgpt reporter plasmid. Our evidence strongly implicates an in situ recombination mechanism in cDNA-cosmid complementation for ER. The complete deduced amino acid sequence of ERCC5 was reconstructed from several cDNA clones encoding a predicted protein of 1,186 amino acids. The ERCC5 protein has extensive sequence similarities, in bipartite domains A and B, to products of RAD repair genes of two yeasts, Saccharomyces cerevisiae RAD2 and Schizosaccharomyces pombe rad13. Sequence, structural, and functional data taken together indicate that ERCC5 and its relatives are probable functional homologs. A second locus represented by S. cerevisiae YKL510 and S. pombe rad2 genes is structurally distinct from the ERCC5 locus but retains vestigial A and B domain similarities. Our analyses suggest that ERCC5 is a nuclear-localized protein with one or more highly conserved helix-loop-helix segments within domains A and B.
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37
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MacInnes MA, Dickson JA, Hernandez RR, Learmonth D, Lin GY, Mudgett JS, Park MS, Schauer S, Reynolds RJ, Strniste GF. Human ERCC5 cDNA-cosmid complementation for excision repair and bipartite amino acid domains conserved with RAD proteins of Saccharomyces cerevisiae and Schizosaccharomyces pombe. Mol Cell Biol 1993; 13:6393-402. [PMID: 8413238 PMCID: PMC364698 DOI: 10.1128/mcb.13.10.6393-6402.1993] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Several human genes related to DNA excision repair (ER) have been isolated via ER cross-species complementation (ERCC) of UV-sensitive CHO cells. We have now isolated and characterized cDNAs for the human ERCC5 gene that complement CHO UV135 cells. The ERCC5 mRNA size is about 4.6 kb. Our available cDNA clones are partial length, and no single clone was active for UV135 complementation. When cDNAs were mixed pairwise with a cosmid clone containing an overlapping 5'-end segment of the ERCC5 gene, DNA transfer produced UV-resistant colonies with 60 to 95% correction of UV resistance relative to either a genomic ERCC5 DNA transformant or the CHO AA8 progenitor cells. cDNA-cosmid transformants regained intermediate levels (20 to 45%) of ER-dependent reactivation of a UV-damaged pSVCATgpt reporter plasmid. Our evidence strongly implicates an in situ recombination mechanism in cDNA-cosmid complementation for ER. The complete deduced amino acid sequence of ERCC5 was reconstructed from several cDNA clones encoding a predicted protein of 1,186 amino acids. The ERCC5 protein has extensive sequence similarities, in bipartite domains A and B, to products of RAD repair genes of two yeasts, Saccharomyces cerevisiae RAD2 and Schizosaccharomyces pombe rad13. Sequence, structural, and functional data taken together indicate that ERCC5 and its relatives are probable functional homologs. A second locus represented by S. cerevisiae YKL510 and S. pombe rad2 genes is structurally distinct from the ERCC5 locus but retains vestigial A and B domain similarities. Our analyses suggest that ERCC5 is a nuclear-localized protein with one or more highly conserved helix-loop-helix segments within domains A and B.
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Affiliation(s)
- M A MacInnes
- Life Sciences Division, Los Alamos National Laboratory, New Mexico 87545
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38
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SPK1 is an essential S-phase-specific gene of Saccharomyces cerevisiae that encodes a nuclear serine/threonine/tyrosine kinase. Mol Cell Biol 1993. [PMID: 8355715 DOI: 10.1128/mcb.13.9.5829] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SPK1 was originally discovered in an immunoscreen for tyrosine-protein kinases in Saccharomyces cerevisiae. We have used biochemical and genetic techniques to investigate the function of this gene and its encoded protein. Hybridization of an SPK1 probe to an ordered genomic library showed that SPK1 is adjacent to PEP4 (chromosome XVI L). Sporulation of spk1/+ heterozygotes gave rise to spk1 spores that grew into microcolonies but could not be further propagated. These colonies were greatly enriched for budded cells, especially those with large buds. Similarly, eviction of CEN plasmids bearing SPK1 from cells with a chromosomal SPK1 disruption yielded viable cells with only low frequency. Spk1 protein was identified by immunoprecipitation and immunoblotting. It was associated with protein-Ser, Thr, and Tyr kinase activity in immune complex kinase assays. Spk1 was localized to the nucleus by immunofluorescence. The nucleotide sequence of the SPK1 5' noncoding region revealed that SPK1 contains two MluI cell cycle box elements. These elements confer S-phase-specific transcription to many genes involved in DNA synthesis. Northern (RNA) blotting of synchronized cells verified that the SPK1 transcript is coregulated with other MluI box-regulated genes. The SPK1 upstream region also includes a domain highly homologous to sequences involved in induction of RAD2 and other excision repair genes by agents that induce DNA damage. spk1 strains were hypersensitive to UV irradiation. Taken together, these findings indicate that SPK1 is a dual-specificity (Ser/Thr and Tyr) protein kinase that is essential for viability. The cell cycle-dependent transcription, presence of DNA damage-related sequences, requirement for UV resistance, and nuclear localization of Spk1 all link this gene to a crucial S-phase-specific role, probably as a positive regulator of DNA synthesis.
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39
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Zheng P, Fay DS, Burton J, Xiao H, Pinkham JL, Stern DF. SPK1 is an essential S-phase-specific gene of Saccharomyces cerevisiae that encodes a nuclear serine/threonine/tyrosine kinase. Mol Cell Biol 1993; 13:5829-42. [PMID: 8355715 PMCID: PMC360328 DOI: 10.1128/mcb.13.9.5829-5842.1993] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
SPK1 was originally discovered in an immunoscreen for tyrosine-protein kinases in Saccharomyces cerevisiae. We have used biochemical and genetic techniques to investigate the function of this gene and its encoded protein. Hybridization of an SPK1 probe to an ordered genomic library showed that SPK1 is adjacent to PEP4 (chromosome XVI L). Sporulation of spk1/+ heterozygotes gave rise to spk1 spores that grew into microcolonies but could not be further propagated. These colonies were greatly enriched for budded cells, especially those with large buds. Similarly, eviction of CEN plasmids bearing SPK1 from cells with a chromosomal SPK1 disruption yielded viable cells with only low frequency. Spk1 protein was identified by immunoprecipitation and immunoblotting. It was associated with protein-Ser, Thr, and Tyr kinase activity in immune complex kinase assays. Spk1 was localized to the nucleus by immunofluorescence. The nucleotide sequence of the SPK1 5' noncoding region revealed that SPK1 contains two MluI cell cycle box elements. These elements confer S-phase-specific transcription to many genes involved in DNA synthesis. Northern (RNA) blotting of synchronized cells verified that the SPK1 transcript is coregulated with other MluI box-regulated genes. The SPK1 upstream region also includes a domain highly homologous to sequences involved in induction of RAD2 and other excision repair genes by agents that induce DNA damage. spk1 strains were hypersensitive to UV irradiation. Taken together, these findings indicate that SPK1 is a dual-specificity (Ser/Thr and Tyr) protein kinase that is essential for viability. The cell cycle-dependent transcription, presence of DNA damage-related sequences, requirement for UV resistance, and nuclear localization of Spk1 all link this gene to a crucial S-phase-specific role, probably as a positive regulator of DNA synthesis.
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Affiliation(s)
- P Zheng
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06510
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40
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Scherly D, Nouspikel T, Corlet J, Ucla C, Bairoch A, Clarkson SG. Complementation of the DNA repair defect in xeroderma pigmentosum group G cells by a human cDNA related to yeast RAD2. Nature 1993; 363:182-5. [PMID: 8483504 DOI: 10.1038/363182a0] [Citation(s) in RCA: 150] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Defects in human DNA repair proteins can give rise to the autosomal recessive disorders xeroderma pigmentosum (XP) and Cockayne's syndrome (CS), sometimes even together. Seven XP and three CS complementation groups have been identified that are thought to be due to mutations in genes from the nucleotide excision repair pathway. Here we isolate frog and human complementary DNAs that encode proteins resembling RAD2, a protein involved in this pathway in yeast. Alignment of these three polypeptides, together with two other RAD2 related proteins, reveals that their conserved sequences are largely confined to two regions. Expression of the human cDNA in vivo restores to normal the sensitivity to ultraviolet light and unscheduled DNA synthesis of lymphoblastoid cells from XP group G, but not CS group A. The XP-G correcting protein XPGC is generated from a messenger RNA of approximately 4 kilobases that is present in normal amounts in the XP-G cell line.
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Affiliation(s)
- D Scherly
- Department of Genetics and Microbiology, University Medical Centre (CMU), Geneva, Switzerland
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41
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Carr AM, Sheldrick KS, Murray JM, al-Harithy R, Watts FZ, Lehmann AR. Evolutionary conservation of excision repair in Schizosaccharomyces pombe: evidence for a family of sequences related to the Saccharomyces cerevisiae RAD2 gene. Nucleic Acids Res 1993; 21:1345-9. [PMID: 8464724 PMCID: PMC309318 DOI: 10.1093/nar/21.6.1345] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Cells mutated at the rad13 locus in the fission yeast, Schizosaccharomyces pombe are deficient in excision-repair of UV damage. We have cloned the S.pombe rad13 gene by its ability to complement the UV sensitivity of a rad13 mutant. The gene is not essential for cell proliferation. Sequence analysis of the cloned gene revealed an open reading-frame of 1113 amino acids with structural homology to the RAD2 gene of the distantly related Saccharomyces cerevisiae. The sequence similarity is confined to three domains, two close to the N-terminus of the encoded protein, the third being close to the C-terminus. The central region of about 500 amino acids shows little similarity between the two organisms. The first and third domains are also found in a related yet distinct pair of homologous S.pombe/S.cerevisiae DNA repair genes (rad2/YKL510), which have only a very short region between these two conserved domains. Using the polymerase chain reaction with degenerate primers, we have isolated fragments from a gene homologous to rad13/RAD2 from Aspergillus nidulans. These findings define new functional domains involved in excision-repair, as well as identifying a conserved family of genes related to RAD2.
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Affiliation(s)
- A M Carr
- MRC Cell Mutation Unit, Sussex University, Falmer, Brighton, UK
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42
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Singhal RK, Hinkle DC, Lawrence CW. The REV3 gene of Saccharomyces cerevisiae is transcriptionally regulated more like a repair gene than one encoding a DNA polymerase. MOLECULAR & GENERAL GENETICS : MGG 1992; 236:17-24. [PMID: 1494346 DOI: 10.1007/bf00279638] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We measured the relative steady-state levels of the mRNA transcribed from the Saccharomyces cerevisiae REV3 gene in cells at different stages of the mitotic and meiotic cycles, and after UV irradiation. This gene is thought to encode a DNA polymerase concerned only with a specific recovery function, the replication on mutagen-damaged templates that produces damaged-induced mutations. In keeping with this proposed function, the REV3 gene showed no evidence of the periodic transcription at the G1/S boundary of the mitotic and meiotic cycle that occurs with genes encoding replication enzymes. However, levels of REV3 mRNA were much increased in late meiotic cells, like those of transcripts of some other DNA repair-related genes. Steady-state levels of REV3 transcript were increased only slightly in response to UV irradiation.
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Affiliation(s)
- R K Singhal
- Department of Biophysics, University of Rochester, NY 14642
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43
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Nucleotide sequence and transcriptional regulation of the yeast recombinational repair gene RAD51. Mol Cell Biol 1992. [PMID: 1620128 DOI: 10.1128/mcb.12.7.3235] [Citation(s) in RCA: 145] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The RAD51 gene of Saccharomyces cerevisiae is required both for recombination and for the repair of DNA damage caused by X rays. Here we report the sequence and transcriptional regulation of this gene. The RAD51 protein shares significant homology (approximately 50%) over a 70-amino-acid with the RAD57 protein (J.A. Kans and R.K. Mortimer, Gene 105:139-140, 1991), the product of another yeast recombinational repair gene, and also moderate (approximately 27%), but potentially significant, homology with the bacterial RecA protein. The homologies cover a region that encodes a putative nucleotide binding site of the RAD51 protein. Sequences upstream of the coding region for RAD51 protein share homology with the damage response sequence element of RAD54, an upstream activating sequence required for damage regulation of the RAD54 transcript, and also contain two sites for restriction enzyme MluI; the presence of MluI restriction sites has been associated with cell cycle regulation. A 1.6-kb transcript corresponding to RAD51 was observed, and levels of this transcript increased rapidly after exposure to relatively low doses of X-rays. Additionally, RAD51 transcript levels were found to that of a group of genes involved primarily in DNA synthesis and replication which are thought to be coordinately cell cycle regulated. Cells arrested in early G1 were still capable of increasing levels of RAD51 transcript after irradiation, indicating that increased RAD51 transcript levels after X-ray exposure are not solely due to an X-ray-induced cessation of the cell cycle at a period when the level of RAD51 expression is normally high.
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44
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Xiao W, Samson L. The Saccharomyces cerevisiae MGT1 DNA repair methyltransferase gene: its promoter and entire coding sequence, regulation and in vivo biological functions. Nucleic Acids Res 1992; 20:3599-606. [PMID: 1641326 PMCID: PMC334007 DOI: 10.1093/nar/20.14.3599] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We previously cloned a yeast DNA fragment that, when fused with the bacterial lacZ promoter, produced O6-methylguanine DNA repair methyltransferase (MGT1) activity and alkylation resistance in Escherichia coli (Xiao et al., EMBO J. 10,2179). Here we describe the isolation of the entire MGT1 gene and its promoter by sequence directed chromosome integration and walking. The MGT1 promoter was fused to a lacZ reporter gene to study how MGT1 expression is controlled. MGT1 is not induced by alkylating agents, nor is it induced by other DNA damaging agents such as UV light. However, deletion analysis defined an upstream repression sequence, whose removal dramatically increased basal level gene expression. The polypeptide deduced from the complete MGT1 sequence contained 18 more N-terminal amino acids than that previously determined; the role of these 18 amino acids, which harbored a potential nuclear localization signal, was explored. The MGT1 gene was also cloned under the GAL1 promoter, so that MTase levels could be manipulated, and we examined MGT1 function in a MTase deficient yeast strain (mgt1). The extent of resistance to both alkylation-induced mutation and cell killing directly correlated with MTase levels. Finally we show that mgt1 S.cerevisiae has a higher rate of spontaneous mutation than wild type cells, indicating that there is an endogenous source of DNA alkylation damage in these eukaryotic cells and that one of the in vivo roles of MGT1 is to limit spontaneous mutations.
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Affiliation(s)
- W Xiao
- Department of Molecular and Cellular Toxicology, Harvard School of Public Health, Boston, MA 02115
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45
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Basile G, Aker M, Mortimer RK. Nucleotide sequence and transcriptional regulation of the yeast recombinational repair gene RAD51. Mol Cell Biol 1992; 12:3235-46. [PMID: 1620128 PMCID: PMC364538 DOI: 10.1128/mcb.12.7.3235-3246.1992] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The RAD51 gene of Saccharomyces cerevisiae is required both for recombination and for the repair of DNA damage caused by X rays. Here we report the sequence and transcriptional regulation of this gene. The RAD51 protein shares significant homology (approximately 50%) over a 70-amino-acid with the RAD57 protein (J.A. Kans and R.K. Mortimer, Gene 105:139-140, 1991), the product of another yeast recombinational repair gene, and also moderate (approximately 27%), but potentially significant, homology with the bacterial RecA protein. The homologies cover a region that encodes a putative nucleotide binding site of the RAD51 protein. Sequences upstream of the coding region for RAD51 protein share homology with the damage response sequence element of RAD54, an upstream activating sequence required for damage regulation of the RAD54 transcript, and also contain two sites for restriction enzyme MluI; the presence of MluI restriction sites has been associated with cell cycle regulation. A 1.6-kb transcript corresponding to RAD51 was observed, and levels of this transcript increased rapidly after exposure to relatively low doses of X-rays. Additionally, RAD51 transcript levels were found to that of a group of genes involved primarily in DNA synthesis and replication which are thought to be coordinately cell cycle regulated. Cells arrested in early G1 were still capable of increasing levels of RAD51 transcript after irradiation, indicating that increased RAD51 transcript levels after X-ray exposure are not solely due to an X-ray-induced cessation of the cell cycle at a period when the level of RAD51 expression is normally high.
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Affiliation(s)
- G Basile
- Department of Molecular and Cellular Biology, University of California, Berkeley
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46
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Siede W, Friedberg EC. Regulation of the yeast RAD2 gene: DNA damage-dependent induction correlates with protein binding to regulatory sequences and their deletion influences survival. MOLECULAR & GENERAL GENETICS : MGG 1992; 232:247-56. [PMID: 1557031 DOI: 10.1007/bf00280003] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In the yeast Saccharomyces cerevisiae the RAD2 gene is absolutely required for damage-specific incision of DNA during nucleotide excision repair and is inducible by DNA-damaging agents. In the present study we correlated sensitivity to killing by DNA-damaging agents with the deletion of previously defined specific promoter elements. Deletion of the element DRE2 increased the UV sensitivity of cells in both the G1/early S and S/G2 phases of the cell cycle as well as in stationary phase. On the other hand, increased UV sensitivity associated with deletion of the sequence-related element DRE1 was restricted to cells irradiated in G1/S. Specific binding of protein(s) to the promoter elements DRE1 and DRE2 was observed under non-inducing conditions using gel retardation assays. Exposure of cells to DNA-damaging agents resulted in increased protein binding that was dependent on de novo protein synthesis.
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Affiliation(s)
- W Siede
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235
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47
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Jacquier A, Legrain P, Dujon B. Sequence of a 10.7 kb segment of yeast chromosome XI identifies the APN1 and the BAF1 loci and reveals one tRNA gene and several new open reading frames including homologs to RAD2 and kinases. Yeast 1992; 8:121-32. [PMID: 1561835 DOI: 10.1002/yea.320080207] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We report here the DNA sequence of a segment of chromosome XI of Saccharomyces cerevisiae extending over 10.7 kb. The sequence was determined using a double-strand sequencing strategy adapted from the random-clone strategy. The segment contains seven non-overlapping long open reading frames, YKL500, 505, 510, 513, 516, 518 and 520 and one tRNA gene. YKL505 and YKL513 are two already sequenced genes, the BAF1/ABF1 and the APN1 genes, respectively. YKL510 exhibits a strong homology to the RAD2 protein and YKL516 is presumably a protein kinase.
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Affiliation(s)
- A Jacquier
- Unité de Génétique Moléculaire des Levures (URA 1149 du CNRS), Institut Pasteur, Paris, France
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48
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Brozmanová J, Cernáková L, Vlcková V, Duraj J, Fridrichová I. The Escherichia coli recA gene increases resistance of the yeast Saccharomyces cerevisiae to ionizing and ultraviolet radiation. MOLECULAR & GENERAL GENETICS : MGG 1991; 227:473-80. [PMID: 1865881 DOI: 10.1007/bf00273940] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The Escherichia coli recA protein coding region was ligated into an extrachromosomally replicating yeast expression vector downstream of the yeast alcohol dehydrogenase promoter region to produce plasmid pADHrecA. Transformation of the wild-type yeast strains YNN-27 and 7799-4B, as well as the recombination-deficient rad52-1 C5-6 mutant, with this shuttle plasmid resulted in the expression of the bacterial 38 kDa RecA protein in exponential phase cells. The wild-type YNN27 and 7799-4B transformants expressing the bacterial recA gene showed increased resistance to the toxic effects of both ionizing and ultraviolet radiation. RecA moderately stimulated the UV-induced mutagenic response of 7799-4B cells. Transformation of the rad52-1 mutant with plasmid pADHrecA did not result in the complementation of sensitivity to ionizing radiation. Thus, the RecA protein endows the yeast cells with additional activities, which were shown to be error-prone and dependent on the RAD52 gene.
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Affiliation(s)
- J Brozmanová
- Department of Molecular Genetics, Slovak Academy of Sciences, Bratislava, Czechoslovakia
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49
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Abstract
Eukaryotic cells are able to mount several genetically complex cellular responses to DNA damage. The yeast Saccharomyces cerevisiae is a genetically well characterized organism that is also amenable to molecular and biochemical studies. Hence, this organism has provided a useful and informative model for dissecting the biochemistry and molecular biology of DNA repair in eukaryotes.
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Affiliation(s)
- E C Friedberg
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235
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50
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Jones JS, Prakash L. Transcript levels of the Saccharomyces cerevisiae DNA repair gene RAD18 increase in UV irradiated cells and during meiosis but not during the mitotic cell cycle. Nucleic Acids Res 1991; 19:893-8. [PMID: 2017370 PMCID: PMC333727 DOI: 10.1093/nar/19.4.893] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have examined the transcript levels of the Saccharomyces cerevisiae DNA repair gene RAD18 in UV irradiated cells, in the mitotic cell cycle, and during meiosis. Levels of RAD18 mRNA increased upon UV irradiation, but remained constant during the mitotic cell cycle. During meiosis, RAD18 mRNA levels rose about 4 fold at a stage coincident with the period when high levels of genetic recombination occur. RAD18 resembles the other DNA repair genes, RAD2, RAD6, RAD7, RAD23, and RAD54, all of which also exhibit increased transcription in response to DNA damage and during meiosis. Comparisons of sequences in 5' flanking regions of RAD genes suggest that different upstream sequences are involved in regulating the expression of DNA repair genes belonging to different epistasis groups.
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Affiliation(s)
- J S Jones
- Department of Biophysics, University of Rochester School of Medicine, NY 14642
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