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Lee MS, Yu M, Kim KY, Park GH, Kwack K, Kim KP. Functional Validation of Rare Human Genetic Variants Involved in Homologous Recombination Using Saccharomyces cerevisiae. PLoS One 2015; 10:e0124152. [PMID: 25938495 PMCID: PMC4418691 DOI: 10.1371/journal.pone.0124152] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 03/10/2015] [Indexed: 12/02/2022] Open
Abstract
Systems for the repair of DNA double-strand breaks (DSBs) are necessary to maintain genome integrity and normal functionality of cells in all organisms. Homologous recombination (HR) plays an important role in repairing accidental and programmed DSBs in mitotic and meiotic cells, respectively. Failure to repair these DSBs causes genome instability and can induce tumorigenesis. Rad51 and Rad52 are two key proteins in homologous pairing and strand exchange during DSB-induced HR; both are highly conserved in eukaryotes. In this study, we analyzed pathogenic single nucleotide polymorphisms (SNPs) in human RAD51 and RAD52 using the Polymorphism Phenotyping (PolyPhen) and Sorting Intolerant from Tolerant (SIFT) algorithms and observed the effect of mutations in highly conserved domains of RAD51 and RAD52 on DNA damage repair in a Saccharomyces cerevisiae-based system. We identified a number of rad51 and rad52 alleles that exhibited severe DNA repair defects. The functionally inactive SNPs were located near ATPase active site of Rad51 and the DNA binding domain of Rad52. The rad51-F317I, rad52-R52W, and rad52-G107C mutations conferred hypersensitivity to methyl methane sulfonate (MMS)-induced DNA damage and were defective in HR-mediated DSB repair. Our study provides a new approach for detecting functional and loss-of-function genetic polymorphisms and for identifying causal variants in human DNA repair genes that contribute to the initiation or progression of cancer.
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Affiliation(s)
- Min-Soo Lee
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Mi Yu
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Kyoung-Yeon Kim
- Department of Biomedical Science, CHA University, Seongnam, Korea
| | - Geun-Hee Park
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - KyuBum Kwack
- Department of Biomedical Science, CHA University, Seongnam, Korea
- * E-mail: (KPK); (KBK)
| | - Keun P. Kim
- Department of Life Science, Chung-Ang University, Seoul, Korea
- * E-mail: (KPK); (KBK)
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2
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Abstract
Homologous recombination (HR) performs crucial functions including DNA repair, segregation of homologous chromosomes, propagation of genetic diversity, and maintenance of telomeres. HR is responsible for the repair of DNA double-strand breaks and DNA interstrand cross-links. The process of HR is initiated at the site of DNA breaks and gaps and involves a search for homologous sequences promoted by Rad51 and auxiliary proteins followed by the subsequent invasion of broken DNA ends into the homologous duplex DNA that then serves as a template for repair. The invasion produces a cross-stranded structure, known as the Holliday junction. Here, we describe the properties of Rad54, an important and versatile HR protein that is evolutionarily conserved in eukaryotes. Rad54 is a motor protein that translocates along dsDNA and performs several important functions in HR. The current review focuses on the recently identified Rad54 activities which contribute to the late phase of HR, especially the branch migration of Holliday junctions.
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Affiliation(s)
- Alexander V Mazin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA.
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3
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Osakabe K, Abe K, Yoshioka T, Osakabe Y, Todoriki S, Ichikawa H, Hohn B, Toki S. Isolation and characterization of the RAD54 gene from Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 48:827-42. [PMID: 17227544 DOI: 10.1111/j.1365-313x.2006.02927.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Homologous recombination (HR) is an essential process in maintaining genome integrity and variability. In eukaryotes, the Rad52 epistasis group proteins are involved in meiotic recombination and/or HR repair. One member of this group, Rad54, belongs to the SWI2/SNF2 family of DNA-stimulated ATPases. Recent studies indicate that Rad54 has important functions in HR, both as a chromatin remodelling factor and as a mediator of the Rad51 nucleoprotein filament. Despite the importance of Rad54 in HR, no study of Rad54 from plants has yet been performed. Here, we cloned the full-length AtRAD54 cDNA sequence; an open reading frame of 910 amino acids encodes a protein with a predicted molecular mass of 101.9 kDa. Western blotting analysis showed that the AtRad54 protein was indeed expressed as a protein of approximately 110 kDa in Arabidopsis. The predicted protein sequence of AtRAD54 contains seven helicase domains, which are conserved in all other Rad54s. Yeast two-hybrid analysis revealed an interaction between Arabidopsis Rad51 and Rad54. AtRAD54 transcripts were found in all tissues examined, with the highest levels of expression in flower buds. Expression of AtRAD54 was induced by gamma-irradiation. A T-DNA insertion mutant of AtRAD54 devoid of full-length AtRAD54 expression was viable and fertile; however, it showed increased sensitivity to gamma-irradiation and the cross-linking reagent cisplatin. In addition, the efficiency of somatic HR in the mutant plants was reduced relative to that in wild-type plants. Our findings point to an important role for Rad54 in HR repair in higher plants.
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Affiliation(s)
- Keishi Osakabe
- Plant Genetic Engineering Research Unit, Division of Plant Sciences, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
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4
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Abstract
Homologous recombination (HR) is a ubiquitous cellular pathway that mediates transfer of genetic information between homologous or near homologous (homeologous) DNA sequences. During meiosis it ensures proper chromosome segregation in the first division. Moreover, HR is critical for the tolerance and repair of DNA damage, as well as in the recovery of stalled and broken replication forks. Together these functions preserve genomic stability and assure high fidelity transmission of the genetic material in the mitotic and meiotic cell divisions. This review will focus on the Rad54 protein, a member of the Snf2-family of SF2 helicases, which translocates on dsDNA but does not display strand displacement activity typical for a helicase. A wealth of genetic, cytological, biochemical and structural data suggests that Rad54 is a core factor of HR, possibly acting at multiple stages during HR in concert with the central homologous pairing protein Rad51.
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Affiliation(s)
- Wolf-Dietrich Heyer
- Sections of Microbiology, University of California Davis, CA 95616-8665, USA.
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5
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Sonoda E, Takata M, Yamashita YM, Morrison C, Takeda S. Homologous DNA recombination in vertebrate cells. Proc Natl Acad Sci U S A 2001; 98:8388-94. [PMID: 11459980 PMCID: PMC37448 DOI: 10.1073/pnas.111006398] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The RAD52 epistasis group genes are involved in homologous DNA recombination, and their primary structures are conserved from yeast to humans. Although biochemical studies have suggested that the fundamental mechanism of homologous DNA recombination is conserved from yeast to mammals, recent studies of vertebrate cells deficient in genes of the RAD52 epistasis group reveal that the role of each protein is not necessarily the same as that of the corresponding yeast gene product. This review addresses the roles and mechanisms of homologous recombination-mediated repair with a special emphasis on differences between yeast and vertebrate cells.
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Affiliation(s)
- E Sonoda
- Department of Radiation Genetics, Faculty of Medicine, Kyoto University, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan
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6
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Clever B, Interthal H, Schmuckli-Maurer J, King J, Sigrist M, Heyer WD. Recombinational repair in yeast: functional interactions between Rad51 and Rad54 proteins. EMBO J 1997; 16:2535-44. [PMID: 9171366 PMCID: PMC1169853 DOI: 10.1093/emboj/16.9.2535] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Rad51p is a eukaryotic homolog of RecA, the central homologous pairing and strand exchange protein in Escherichia coli. Rad54p belongs to the Swi2p/Snf2p family of DNA-stimulated ATPases. Both proteins are also important members of the RAD52 group which controls recombinational DNA damage repair of double-strand breaks and other DNA lesions in Saccharomyces cerevisiae. Here we demonstrate by genetic, molecular and biochemical criteria that Rad51 and Rad54 proteins interact. Strikingly, overexpression of Rad54p can functionally suppress the UV and methyl methanesulfonate sensitivity caused by a deletion of the RAD51 gene. However, no suppression was observed for the defects of rad51 cells in the repair of gamma-ray-induced DNA damage, mating type switching or spontaneous hetero-allelic recombination. This suppression is genetically dependent on the presence of two other members of the recombinational repair group, RAD55 and RAD57. Our data provide compelling evidence that Rad51 and Rad54 proteins interact in vivo and that this interaction is functionally important for recombinational DNA damage repair. As both proteins are conserved throughout evolution from yeasts to humans, a similar protein-protein interaction may be expected in other organisms.
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Affiliation(s)
- B Clever
- Institute of General Microbiology, Bern, Switzerland
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7
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Bezzubova O, Silbergleit A, Yamaguchi-Iwai Y, Takeda S, Buerstedde JM. Reduced X-ray resistance and homologous recombination frequencies in a RAD54-/- mutant of the chicken DT40 cell line. Cell 1997; 89:185-93. [PMID: 9108474 DOI: 10.1016/s0092-8674(00)80198-1] [Citation(s) in RCA: 220] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
rad54 mutants of the yeast Saccharomyces cerevisiae are extremely X-ray sensitive and have decreased mitotic recombination frequencies because of a defect in double-strand break repair. A RAD54 homolog was disrupted in the chicken B cell line DT40, which undergoes immunoglobulin gene conversion and exhibits unusually high ratios of targeted to random integration after DNA transfection. Homozygous RAD54-/- mutant clones were highly X-ray sensitive compared to wildtype cells. The rate of immunoglobulin gene conversion was 6- to 8-fold reduced, and the frequency of targeted integration was at least two orders of magnitude decreased in the mutant clones. Reexpression of the RAD54 cDNA restored radiation resistance and targeted integration activity. The reported phenotype provides the first genetic evidence of a link between double-strand break repair and homologous recombination in vertebrate cells.
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8
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Kanaar R, Troelstra C, Swagemakers SM, Essers J, Smit B, Franssen JH, Pastink A, Bezzubova OY, Buerstedde JM, Clever B, Heyer WD, Hoeijmakers JH. Human and mouse homologs of the Saccharomyces cerevisiae RAD54 DNA repair gene: evidence for functional conservation. Curr Biol 1996; 6:828-38. [PMID: 8805304 DOI: 10.1016/s0960-9822(02)00606-1] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Homologous recombination is of eminent importance both in germ cells, to generate genetic diversity during meiosis, and in somatic cells, to safeguard DNA from genotoxic damage. The genetically well-defined RAD52 pathway is required for these processes in the yeast Saccharomyces cerevisiae. Genes similar to those in the RAD52 group have been identified in mammals. It is not known whether this conservation of primary sequence extends to conservation of function. RESULTS Here we report the isolation of cDNAs encoding a human and a mouse homolog of RAD54. The human (hHR54) and mouse (mHR54) proteins were 48% identical to Rad54 and belonged to the SNF2/SW12 family, which is characterized by amino-acid motifs found in DNA-dependent ATPases. The hHR54 gene was mapped to chromosome 1p32, and the hHR54 protein was located in the nucleus. We found that the levels of hHR54 mRNA increased in late G1 phase, as has been found for RAD54 mRNA. The level of mHR54 mRNA was elevated in organs of germ cell and lymphoid development and increased mHR54 expression correlated with the meiotic phase of spermatogenesis. The hHR54 cDNA could partially complement the methyl methanesulfonate-sensitive phenotype of S. cerevisiae rad54 delta cells. CONCLUSIONS The tissue-specific expression of mHR54 is consistent with a role for the gene in recombination. The complementation experiments show that the DNA repair function of Rad54 is conserved from yeast to humans. Our findings underscore the fundamental importance of DNA repair pathways: even though they are complex and involve multiple proteins, they seem to be functionally conserved throughout the eukaryotic kingdom.
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Affiliation(s)
- R Kanaar
- Department of Cell Biology and Genetics, Erasmus University Rotterdam, The Netherlands.
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9
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Kaytor MD, Livingston DM. Allele-specific suppression of temperature-sensitive mutations of the Saccharomyces cerevisiae RAD52 gene. Curr Genet 1996; 29:203-10. [PMID: 8595665 DOI: 10.1007/bf02221549] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We screened for rad52 suppressors against temperature-sensitive (ts), missense, nonsense, and deletion rad52 mutations. Except for the deletion strain all mutants yielded suppressor candidates, indicating that suppressors completely bypassing the need for RAD52 are rare. Characterization of seven, recessive extragenic suppressors from our screen and two previously identified suppressors revealed that nearly all exhibit allele specificity. The allele specificity is positional in that suppressors that suppress a ts mutation in the C-terminal third of the coding region do not suppress three ts mutations in the N-terminal third. Conversely, suppressors against one of the three N-terminal mutations suppress more than one of these mutations but not the C-terminal mutation.
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Affiliation(s)
- M D Kaytor
- Department of Biochemistry, University of Minnesota, Minneapolis, MN 55455, USA
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10
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Muris DF, Vreeken K, Carr AM, Murray JM, Smit C, Lohman PH, Pastink A. Isolation of the Schizosaccharomyces pombe RAD54 homologue, rhp54+, a gene involved in the repair of radiation damage and replication fidelity. J Cell Sci 1996; 109 ( Pt 1):73-81. [PMID: 8834792 DOI: 10.1242/jcs.109.1.73] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The RAD54 gene of Saccharomyces cerevisiae encodes a putative helicase, which is involved in the recombinational repair of DNA damage. The RAD54 homologue of the fission yeast Schizosaccharomyces pombe, rhp54+, was isolated by using the RAD54 gene as a heterologous probe. The gene is predicted to encode a protein of 852 amino acids. The overall homology between the mutual proteins of the two species is 67% with 51% identical amino acids and 16% similar amino acids. A rhp54 deletion mutant is very sensitive to both ionizing radiation and UV. Fluorescence microscopy of the rhp54 mutant cells revealed that a large portion of the cells are elongated and occasionally contain aberrant nuclei. In addition, FACS analysis showed an increased DNA content in comparison with wild-type cells. Through a minichromosome-loss assay it was shown that the rhp54 deletion mutant has a very high level of chromosome loss. Furthermore, the rhp54 mutation in either a rad17 or a cdc2.3w mutant background (where the S-phase/mitosis checkpoint is absent) shows a significant reduction in viability. It is hypothesized that the rhp54+ gene is involved in the recombinational repair of UV and X-ray damage and plays a role in the processing of replication-specific lesions.
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Affiliation(s)
- D F Muris
- Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, Netherlands
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11
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Frankenberg-Schwager M, Jha B, Bär K, Frankenberg D. Molecular mechanism of potentially lethal damage repair. I. Enhanced fidelity of DNA double-strand break rejoining under conditions allowing potentially lethal damage repair. Int J Radiat Biol 1995; 67:277-85. [PMID: 7897276 DOI: 10.1080/09553009514550331] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This study contributes to the elucidation of the molecular mechanism underlying potentially lethal damage (PLD) repair. Repair of DNA double-strand breaks (dsbs) is involved in PLD repair in yeast, i.e. in the enhanced survival of cells due to post-irradiation treatment under non-growth conditions before plating cells on nutrient agar (growth conditions). However, dsbs are rejoined when cells are kept either in non-growth or growth medium. One possibility to explain the enhanced survival of cells after post-irradiation treatment in non-growth medium might be an enhanced fidelity of dsb rejoining under non-growth relative to growth conditions. We have addressed this problem by using a plasmid-mediated assay. Into one of the two selectable plasmid markers a single dsb was introduced by a restriction enzyme. The cut plasmid was transfected into an appropriate yeast mutant. Transformants that had correctly rejoined the dsb were selected on the basis of restoration of the function of the cut gene. The yeast mutant was allowed to rejoin the cut plasmid under either non-growth or growth conditions. The results show that the fidelity of dsb rejoining is higher in cells kept under non-growth relative to growth conditions.
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12
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Hafezparast M, Kaur GP, Zdzienicka M, Athwal RS, Lehmann AR, Jeggo PA. Subchromosomal localization of a gene (XRCC5) involved in double strand break repair to the region 2q34-36. SOMATIC CELL AND MOLECULAR GENETICS 1993; 19:413-21. [PMID: 8291019 DOI: 10.1007/bf01233246] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have previously shown that human chromosome 2 can complement both the radiation sensitivity and the defect in double strand break rejoining characteristic of ionizing radiation (IR) group 5 mutants. A number of human-hamster hybrids containing segments of human chromosome 2 were obtained by microcell transfer into two group 5 mutants. In most, but not all, of these hybrids, the repair defect was complemented by the human chromosomal DNA. Two complementing microcell hybrids were irradiated and fused to XR-V15B, an IR group 5 mutant, to generate further hybrids bearing smaller regions of chromosome 2. All hybrids were examined for complementation of the repair defect. The region of chromosome 2 present was determined using PCR with primers specific for various human genes located on chromosome 2. A complementing hybrid bearing only a small region of chromosome 2 was finally generated. From this analysis we deduced that the XRCC5 gene was tightly linked to the marker, TNP1, which is located in the region 2q35.
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Affiliation(s)
- M Hafezparast
- MRC Cell Mutation Unit, University of Sussex, Falmer, Brighton, U.K
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13
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Shinohara A, Ogawa H, Ogawa T. Rad51 protein involved in repair and recombination in S. cerevisiae is a RecA-like protein. Cell 1992; 69:457-70. [PMID: 1581961 DOI: 10.1016/0092-8674(92)90447-k] [Citation(s) in RCA: 932] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The RAD51 gene of S. cerevisiae is involved in mitotic recombination and repair of DNA damage and also in meiosis. We show that the rad51 null mutant accumulates meiosis-specific double-strand breaks (DSBs) at a recombination hotspot and reduces the formation of physical recombinants. Rad51 protein shows structural similarity to RecA protein, the bacterial strand exchange protein. Furthermore, we have found that Rad51 protein is similar to RecA in its DNA binding properties and binds directly to Rad52 protein, which also plays a crucial role in recombination. These results suggest that the Rad51 protein, probably together with Rad52 protein, is involved in a step to convert DSBs to the next intermediate in recombination. Rad51 protein is also homologous to a meiosis-specific Dmc1 protein of S. cerevisiae.
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Affiliation(s)
- A Shinohara
- Department of Biology, Faculty of Science, Osaka University, Japan
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14
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Emery HS, Schild D, Kellogg DE, Mortimer RK. Sequence of RAD54, a Saccharomyces cerevisiae gene involved in recombination and repair. Gene 1991; 104:103-6. [PMID: 1916269 DOI: 10.1016/0378-1119(91)90473-o] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The complete nucleotide sequence of the RAD54 gene of the yeast Saccharomyces cerevisiae has been determined. The sequenced region contains an open reading frame of 2694 bp, and the predicted RAD54 protein has a potential nucleotide-binding site and possible nuclear targeting sequences. Northern analysis reveals a transcript of approx. 3.0 kb which is induced following x-ray irradiation.
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Affiliation(s)
- H S Emery
- Department of Molecular and Cell Biology, University of California, Berkeley 94720
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15
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Abstract
The mechanism that causes large regions of eukaryotic chromosomes to remain unreplicated until late in S phase is not understood. We have found that 67 kb of telomere-adjacent DNA at the right end of chromosome V in S. cerevisiae is replicated late in S phase. An ARS element in this region, ARS501, was shown by two-dimensional gel analysis to be an active origin of replication. Kinetic analyses indicate that the rate of replication fork movement within this late region is similar to that in early replicating regions. Therefore, the delayed replication of the region is a consequence of late origin activation. The results also support the idea that the pattern of interspersed early and late replication along the chromosomes of higher eukaryotes is a consequence of the temporal regulation of origin activation.
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Affiliation(s)
- B M Ferguson
- Department of Genetics SK-50, University of Washington, Seattle 98195
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16
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Simon JR, Moore PD. Transformation and recombination in rad mutants of Saccharomyces cerevisiae. MOLECULAR & GENERAL GENETICS : MGG 1990; 223:241-8. [PMID: 2250651 DOI: 10.1007/bf00265060] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Disruption/deletion mutations in genes of the RAD52 epistasis group of Saccharomyces cerevisiae were examined for their effects on recombination between single- and double-stranded circular DNA substrates and chromosomal genes in a transformation assay. In rad50 mutants there was a small reduction in recombination with single-stranded DNA at the leu2-3, 112 allele; in addition there was an almost complete elimination of recombination at trp1-1 for both single- and double-stranded DNA. Reintroduction of a wild-type RAD50 gene on a replicating plasmid carrying CEN4 restored recombinational competence at trp1-1, indicating that rad50 is defective in gene replacement of this allele. In rad52 mutants a reduction of 30%-50% in recombination involving either single- or double-stranded circular DNA was observed in each experiment when compared to the wild type. This reduction of recombination in rad52 mutants was similar for recombination at the ura3-52 mutant locus where only integration events have been observed, and at the trp1-1 mutant locus, where recombination occurs predominantly by gene replacement. Neither the rad54 nor the rad57 mutations had a significant effect on recombination with single- or double-stranded DNA substrates.
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Affiliation(s)
- J R Simon
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago 60612
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17
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Beckett MA, Weichselbaum RR. Southern analysis of human head and neck cancer cells for homologous sequences using yeast gamma repair genes. J Surg Oncol 1988; 38:257-60. [PMID: 3045425 DOI: 10.1002/jso.2930380410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We employed southern analysis to examine homology between yeast genes RAD 51, RAD 52, RAD 54, and RAD 55 for possible gamma repair genes in radioresistant or repair proficient human tumor cell lines and normal placental DNA. No homology wa observed; however, other strategies including further gene restriction and transfection are underway to identify repair genes in human tumors. Understanding mechanisms of radiation repair might lead to more effective clinical radiation treatment protocols.
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Affiliation(s)
- M A Beckett
- Michael Reese/University of Chicago Center for Radiation Therapy, IL
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18
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Abstract
A new gene, mus-16, is determined by the nitrogen mustard-sensitive Neurospora mutant of Baker, Parish and Curtis (1984) which is defective in the removal of DNA-DNA and DNA-protein crosslinks. This gene is on the left arm of linkage group V between caf-1 and lys-1. The mus-16(JMB) mutant is sensitive to the alkylating agents methyl methanesulfonate (MMS) [dose reduction factor (drf) 8-10 X], N-methyl-N'-nitro-N-nitrosoguanidine (drf 5-6 X), the amino acid histidine and the drug hydroxyurea. It is not sensitive to ultraviolet-light, gamma-irradiation, or mitomycin C (MMC). It shows normal spontaneous mutation rates but increased induction of mutation by MMS. Homozygous crosses are barren, showing no signs of sporulation. Mitotic spontaneous chromosome instability is increased. The mus-16 mutation is similar to several non-excision repair-defective mutants in Neurospora. Some of these may be defective in repair of alkylation damage. The MMC data supports earlier data that in fungi MMC is incapable of forming DNA-DNA crosslinks.
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Affiliation(s)
- H Inoue
- Department of Regulation Biology, Faculty of Science, Saitama University, Urawa, Japan
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19
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Burtscher HJ, Cooper AJ, Couto LB. Cellular responses to DNA damage in the yeast Saccharomyces cerevisiae. Mutat Res 1988; 194:1-8. [PMID: 3290675 DOI: 10.1016/0167-8817(88)90050-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- H J Burtscher
- Department of Pathology, Stanford University School of Medicine, CA 94305
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20
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DNA Repair in Yeast: Genetic Control and Biological Consequences. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/b978-0-12-035413-9.50005-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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21
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Kupiec M, Simchen G. Cloning and mapping of the RAD50 gene of Saccharomyces cerevisiae. MOLECULAR & GENERAL GENETICS : MGG 1984; 193:525-31. [PMID: 6323924 DOI: 10.1007/bf00382094] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The RAD50 gene was cloned as a 4.8 kb fragment in the 2 mu derived plasmid pFL1. The gene resides in a 3.9 kb segment that was subcloned into the plasmid YRp7. The cloned gene complements the deficiency caused by the rad50-1 mutation with respect to gamma-rays, MMS resistance and UV-induced mitotic recombination. Restoration of the Rad+ phenotype occurs when the cloned gene is on a freely replicating multiple-copy plasmid or in the integrated form. Mapping of the cloned gene following integration of the 2 mu plasmid, and of the subclone in plasmid YRp7, showed it to be located on the left arm of chromosome XIV. Tetrad analysis of various crosses involving two different strains carrying rad50-1 showed the mutation to map next to pet2 on chromosome XIV, and not on the right arm of chromosome IV, as previously published.
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22
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Isolation and characterization of yeast DNA repair genes. Curr Genet 1983; 7:85-92. [DOI: 10.1007/bf00365631] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/1982] [Indexed: 10/26/2022]
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