1
|
Lyu XH, Suo F, Li W, Jia GS, Yang YS, Du LL. Diverse modes of chromosome terminal deletion in spontaneous canavanine-resistant Schizosaccharomyces pombe mutants. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001132. [PMID: 38404922 PMCID: PMC10884838 DOI: 10.17912/micropub.biology.001132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 02/03/2024] [Accepted: 02/02/2024] [Indexed: 02/27/2024]
Abstract
Canavanine resistance has been used to analyze mutation rates in the fission yeast Schizosaccharomyces pombe . However, the genetic basis of canavanine resistance in this organism remains incompletely understood. Here, we performed whole genome sequencing on five spontaneously arising canavanine-resistant S. pombe mutants, including the can2-1 mutant isolated in the 1970s. This analysis revealed that three mutants, including can2-1 , experienced terminal deletions of the left arm of chromosome II, leading to the loss of multiple amino acid transporter genes. Interestingly, these three mutants underwent chromosome terminal deletion through distinct mechanisms, including homology-driven translocation, homology-independent chromosome fusion, and de novo telomere addition. Our findings shed new light on the genetic basis of canavanine resistance and mechanisms underlying chromosome terminal deletions in fission yeast.
Collapse
Affiliation(s)
- Xiao-Hui Lyu
- National Institute of Biological Sciences, Beijing, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing, China
| | - Wen Li
- National Institute of Biological Sciences, Beijing, China
| | - Guo-Song Jia
- National Institute of Biological Sciences, Beijing, China
| | - Yu-Sheng Yang
- National Institute of Biological Sciences, Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| |
Collapse
|
2
|
Pai CC, Heitzer E, Bertrand S, Toumazou S, Humphrey TC, Kearsey SE. Using canavanine resistance to measure mutation rates in Schizosaccharomyces pombe. PLoS One 2023; 18:e0271016. [PMID: 36626373 PMCID: PMC9831302 DOI: 10.1371/journal.pone.0271016] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
We constructed a panel of S. pombe strains expressing DNA polymerase ε variants associated with cancer, specifically POLES297F, POLEV411L, POLEL424V, POLES459F, and used these to compare mutation rates determined by canavanine resistance with other selective methods. Canavanine-resistance mutation rates are broadly similar to those seen with reversion of the ade-485 mutation to adenine prototrophy, but lower than 5-fluoroorotic acid (FOA)-resistance rates (inactivation of ura4+ or ura5+ genes). Inactivation of several genes has been associated with canavanine resistance in S. pombe but surprisingly whole genome sequencing showed that 8/8 spontaneous canavanine-resistant mutants have an R175C mutation in the any1/arn1 gene. This gene encodes an α-arrestin-like protein involved in mediating Pub1 ubiquitylation of target proteins, and the phenotypic resistance to canavanine by this single mutation is similar to that shown by the original "can1-1" strain, which also has the any1R175C mutation. Some of the spontaneous mutants have additional mutations in arginine transporters, suggesting that this may marginally increase resistance to canavanine. The any1R175C strain showed internalisation of the Cat1 arginine transporter as previously reported, explaining the canavanine-resistance phenotype.
Collapse
Affiliation(s)
- Chen-Chun Pai
- Department of Oncology, CRUK-MRC Oxford Institute for Radiation Oncology, University of Oxford, ORCRB, Oxford, United Kingdom
| | - Ellen Heitzer
- Institute of Human Genetics, Diagnostic & Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria
| | | | | | - Timothy C. Humphrey
- Department of Oncology, CRUK-MRC Oxford Institute for Radiation Oncology, University of Oxford, ORCRB, Oxford, United Kingdom
| | | |
Collapse
|
3
|
Yang YS, Ning SK, Lyu XH, Suo F, Jia GS, Li W, Du LL. Canavanine resistance mutation can1-1 in Schizosaccharomyces pombe is a missense mutation in the ubiquitin ligase adaptor gene any1. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000538. [PMID: 35300005 PMCID: PMC8922049 DOI: 10.17912/micropub.biology.000538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/05/2022] [Accepted: 03/09/2022] [Indexed: 11/18/2022]
Abstract
In Schizosaccharomyces pombe, the can1-1 mutation confers resistance to the toxic arginine analog canavanine. This mutation has been assumed to disrupt a gene encoding an arginine transporter. In PomBase, the gene SPBC18H10.16 is currently designated can1. Here, we sequenced the genomes of three can1-1 strains. No mutations were found in SPBC18H10.16. Instead, these strains harbor an R175C mutation in the gene any1 (SPBC18H10.20c). any1 encodes an α-arrestin that acts as a ubiquitin ligase adaptor to downregulate plasma membrane amino acid transporters. Our findings indicate that can1-1 is not a loss-of-function mutation in an amino acid transporter gene, but a possible gain-of-function mutation in a gene encoding a negative regulator of amino acid transporters.
Collapse
Affiliation(s)
- Yu-Sheng Yang
- National Institute of Biological Sciences, Beijing, China
| | - Shao-Kai Ning
- National Institute of Biological Sciences, Beijing, China
| | - Xiao-Hui Lyu
- National Institute of Biological Sciences, Beijing, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing, China
| | - Guo-Song Jia
- National Institute of Biological Sciences, Beijing, China
| | - Wen Li
- National Institute of Biological Sciences, Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China
,
Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
,
Correspondence to: Li-Lin Du (
)
| |
Collapse
|
4
|
Pai CC, Hsu KF, Durley SC, Keszthelyi A, Kearsey SE, Rallis C, Folkes LK, Deegan R, Wilkins SE, Pfister SX, De León N, Schofield CJ, Bähler J, Carr AM, Humphrey TC. An essential role for dNTP homeostasis following CDK-induced replication stress. J Cell Sci 2019; 132:jcs226969. [PMID: 30674555 PMCID: PMC6451416 DOI: 10.1242/jcs.226969] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/02/2019] [Indexed: 02/03/2023] Open
Abstract
Replication stress is a common feature of cancer cells, and thus a potentially important therapeutic target. Here, we show that cyclin-dependent kinase (CDK)-induced replication stress, resulting from Wee1 inactivation, is synthetic lethal with mutations disrupting dNTP homeostasis in fission yeast. Wee1 inactivation leads to increased dNTP demand and replication stress through CDK-induced firing of dormant replication origins. Subsequent dNTP depletion leads to inefficient DNA replication, DNA damage and to genome instability. Cells respond to this replication stress by increasing dNTP supply through histone methyltransferase Set2-dependent MBF-induced expression of Cdc22, the catalytic subunit of ribonucleotide reductase (RNR). Disrupting dNTP synthesis following Wee1 inactivation, through abrogating Set2-dependent H3K36 tri-methylation or DNA integrity checkpoint inactivation results in critically low dNTP levels, replication collapse and cell death, which can be rescued by increasing dNTP levels. These findings support a 'dNTP supply and demand' model in which maintaining dNTP homeostasis is essential to prevent replication catastrophe in response to CDK-induced replication stress.
Collapse
Affiliation(s)
- Chen-Chun Pai
- CRUK-MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, ORCRB, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Kuo-Feng Hsu
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
- Department of Surgery, Tri-Service General Hospital, National Defense Medical Centre, Taipei 114, Taiwan
| | - Samuel C Durley
- CRUK-MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, ORCRB, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Andrea Keszthelyi
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, Sussex, BN1 9RQ, UK
| | - Stephen E Kearsey
- Department of Zoology, University of Oxford, Zoology Research & Administration Building, Mansfield Road, Oxford, OX1 3PS, UK
| | - Charalampos Rallis
- Research Department of Genetics, Evolution & Environment, University College London, London, WC1E 6BT, UK
- School of Health, Sport and Bioscience, University of East London, Stratford Campus, E15 4LZ, London, UK
| | - Lisa K Folkes
- CRUK-MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, ORCRB, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Rachel Deegan
- CRUK-MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, ORCRB, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Sarah E Wilkins
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Sophia X Pfister
- CRUK-MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, ORCRB, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Nagore De León
- Department of Zoology, University of Oxford, Zoology Research & Administration Building, Mansfield Road, Oxford, OX1 3PS, UK
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Jürg Bähler
- Research Department of Genetics, Evolution & Environment, University College London, London, WC1E 6BT, UK
| | - Antony M Carr
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, Sussex, BN1 9RQ, UK
| | - Timothy C Humphrey
- CRUK-MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, ORCRB, Roosevelt Drive, Oxford, OX3 7DQ, UK
| |
Collapse
|
5
|
Hecox-Lea BJ, Mark Welch DB. Evolutionary diversity and novelty of DNA repair genes in asexual Bdelloid rotifers. BMC Evol Biol 2018; 18:177. [PMID: 30486781 PMCID: PMC6264785 DOI: 10.1186/s12862-018-1288-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 11/02/2018] [Indexed: 11/26/2022] Open
Abstract
Background Bdelloid rotifers are the oldest, most diverse and successful animal taxon for which males, hermaphrodites, and traditional meiosis are unknown. Their degenerate tetraploid genome, with 2–4 copies of most loci, includes thousands of genes acquired from all domains of life by horizontal transfer. Many bdelloid species thrive in ephemerally aquatic habitats by surviving desiccation at any life stage with no loss of fecundity or lifespan. Their unique genomic diversity and the intense selective pressure of desiccation provide an exceptional opportunity to study the evolution of diversity and novelty in genes involved in DNA repair. Results We used genomic data and RNA-Seq of the desiccation process in the bdelloid Adineta vaga to characterize DNA damage reversal, translesion synthesis, and the major DNA repair pathways: base, nucleotide, and alternate excision repair, mismatch repair (MMR), and double strand break repair by homologous recombination (HR) and classical non-homologous end joining (NHEJ). We identify multiple horizontally transferred DNA damage response genes otherwise unknown in animals (AlkD, Fpg, LigK UVDE), and the presence of genes often considered vertebrate specific, particularly in the NHEJ complex and X family polymerases. While 75–100% of genes involved in MMR and HR are present in 0–2 copies, genes involved in NHEJ, which are present in only a single copy in nearly all other animals, are retained in 3–8 copies. We present structural predictions and expression evidence of neo- or sub-functionalization of multiple copy genes involved in NHEJ and other repair processes. Conclusion The horizontally-acquired genes and duplicated genes in BER and NHEJ suggest resilience to oxidative damage is conferred in part by increased DNA damage recognition and efficient end repair capabilities. The pattern of gene loss and retention in MMR and HR may facilitate recombination and gene conversion between divergent sequences, thus providing at least some of the benefits of sex. The unique retention and divergence of duplicates genes in NHEJ may be facilitated by the lack of efficient selection in the absence of meiotic recombination and independent assortment, and may contribute to the evolutionary success of bdelloids. Electronic supplementary material The online version of this article (10.1186/s12862-018-1288-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Bette J Hecox-Lea
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, USA.,Department of Biology, Northeastern University, Boston, MA, USA
| | - David B Mark Welch
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA, USA.
| |
Collapse
|
6
|
The Uve1 endonuclease is regulated by the white collar complex to protect cryptococcus neoformans from UV damage. PLoS Genet 2013; 9:e1003769. [PMID: 24039606 PMCID: PMC3764193 DOI: 10.1371/journal.pgen.1003769] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Accepted: 07/22/2013] [Indexed: 01/20/2023] Open
Abstract
The pathogenic fungus Cryptococcus neoformans uses the Bwc1-Bwc2 photoreceptor complex to regulate mating in response to light, virulence and ultraviolet radiation tolerance. How the complex controls these functions is unclear. Here, we identify and characterize a gene in Cryptococcus, UVE1, whose mutation leads to a UV hypersensitive phenotype. The homologous gene in fission yeast Schizosaccharomyces pombe encodes an apurinic/apyrimidinic endonuclease acting in the UVDE-dependent excision repair (UVER) pathway. C. neoformans UVE1 complements a S. pombe uvde knockout strain. UVE1 is photoregulated in a Bwc1-dependent manner in Cryptococcus, and in Neurospora crassa and Phycomyces blakesleeanus that are species that represent two other major lineages in the fungi. Overexpression of UVE1 in bwc1 mutants rescues their UV sensitivity phenotype and gel mobility shift experiments show binding of Bwc2 to the UVE1 promoter, indicating that UVE1 is a direct downstream target for the Bwc1-Bwc2 complex. Uve1-GFP fusions localize to the mitochondria. Repair of UV-induced damage to the mitochondria is delayed in the uve1 mutant strain. Thus, in C. neoformans UVE1 is a key gene regulated in response to light that is responsible for tolerance to UV stress for protection of the mitochondrial genome. The majority of fungi sense light using the White Collar complex (WCC), a two-protein combination of a photoreceptor and a transcription factor. The WCC regulates circadian rhythms, sexual development, sporulation, metabolism, and virulence. As such, the exposure to light controls properties of fungi that are beneficial and detrimental to people, depending on the species and its interaction with humans. Despite the importance of light on fungal biology, the underlying evolutionary benefit of light-sensing in fungi has remained a mystery. Here we identify a DNA damage repair endonuclease, Uve1, required for UV stress tolerance in the human pathogen Cryptococcus neoformans. UVE1 is a direct target of the WCC in C. neoformans, and UVE1 homologs are also regulated by WCC in two other major lineages of fungi, the Ascomycota and Mucoromycotina. The divergence of the three groups indicates that for about a billion years the same transcription factor complex has regulated a common gene to protect fungal genomes from deleterious effects of light. Curiously, in C. neoformans Uve1 localizes to mitochondria and contributes to mitochondrial DNA repair, implicating its importance in genome repair of this organelle. Thus, light-sensing in fungi exists to protect them against harmful light, and likely all other responses to light relate to or are a secondary consequence of this selective pressure.
Collapse
|
7
|
Draft Genome Sequence of Herpotrichiellaceae sp. UM 238 Isolated from Human Skin Scraping. GENOME ANNOUNCEMENTS 2013; 1:genomeA00148-12. [PMID: 23409267 PMCID: PMC3569337 DOI: 10.1128/genomea.00148-12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 12/18/2012] [Indexed: 12/18/2022]
Abstract
Herpotrichiellaceae spp. are known to be opportunistic human pathogens. Here, we report the ~28.46-Mb draft genome of Herpotrichiellaceae sp. UM 238, isolated from human skin scraping. The UM 238 genome was found to contain many classes of protective genes that are responsible for fungal adaptation under adverse environmental conditions.
Collapse
|
8
|
Kanamitsu K, Ikeda S. Early Steps in the DNA Base Excision Repair Pathway of a Fission Yeast Schizosaccharomyces pombe. J Nucleic Acids 2010; 2010. [PMID: 20936170 PMCID: PMC2945677 DOI: 10.4061/2010/450926] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 08/12/2010] [Indexed: 12/04/2022] Open
Abstract
DNA base excision repair (BER) accounts for maintaining genomic integrity by removing damaged bases that are generated endogenously or induced by genotoxic agents. In this paper, we describe the roles of enzymes functioning in the early steps of BER in fission yeast. Although BER is an evolutionarily conserved process, some unique features of the yeast repair pathway were revealed by genetic and biochemical approaches. AP sites generated by monofunctional DNA glycosylases are incised mainly by AP lyase activity of Nth1p, a sole bifunctional glycosylase in yeast, to leave a blocked 3′ end. The major AP endonuclease Apn2p functions predominantly in removing the 3′ block. Finally, a DNA polymerase fills the gap, and a DNA ligase seals the nick (Nth1p-dependent or short patch BER). Apn1p backs up Apn2p. In long patch BER, Rad2p endonuclease removes flap DNA containing a lesion after DNA synthesis. A UV-specific endonuclease Uve1p engages in an alternative pathway by nicking DNA on the 5′ side of oxidative damage. Nucleotide excision repair and homologous recombination are involved in repair of BER intermediates including the AP site and single-strand break with the 3′ block. Other enzymes working in 3′ end processing are also discussed.
Collapse
Affiliation(s)
- Kyoichiro Kanamitsu
- Department of Biochemistry, Faculty of Science, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0005, Japan
| | | |
Collapse
|
9
|
Paspaleva K, Moolenaar GF, Goosen N. Damage recognition by UV damage endonuclease from Schizosaccharomyces pombe. DNA Repair (Amst) 2009; 8:600-11. [PMID: 19152795 DOI: 10.1016/j.dnarep.2008.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 12/02/2008] [Accepted: 12/09/2008] [Indexed: 10/21/2022]
Abstract
UV damage endonuclease (UVDE) from Schizosaccharomyces pombe initiates repair of UV lesions and abasic sites by nicking the DNA 5' to the damaged site. In this paper we show that in addition UVDE incises DNA containing a single-strand nick or gap, but that the enzymatic activity on these substrates as well as on abasic sites strongly depends on the presence of a neighbouring pyrimidine residue. This indicates that, although UVDE may have been derived from an ancestral AP endonuclease its major substrate is a UV lesion and not an AP site. We propose that UVDE rotates two nucleotides into a pocket of the protein in order to bring the scissile bond close to the active site and that purine bases are excluded from this pocket. We also show that in the DNA complex residue Tyr-358 of UVDE penetrates the DNA helix causing unstacking of two residues opposite the lesion, thereby stabilizing the protein-DNA interaction, most likely by promoting bending of the DNA. In the absence of Tyr-358 the enzyme exhibits an increased catalytic activity on UV-induced lesions, but only at a lower pH of 6.5. At physiological conditions (pH 7.5) the mutant protein completely looses its catalytic activity although it can still bind to the DNA. We propose that in addition to stabilizing the bend in the DNA the hydrophobic side chain of Tyr-358 shields the active site from exposure to the solvent.
Collapse
Affiliation(s)
- Keti Paspaleva
- Laboratory of Molecular Genetics, Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
| | | | | |
Collapse
|
10
|
Hida Y, Ikeda S. Base Excision Repair of Oxidative DNA Damage in a Catalase-deficient Mutant of Schizosaccharomyces pombe. Genes Environ 2008. [DOI: 10.3123/jemsge.30.86] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
11
|
Crystal structure of the DNA repair enzyme ultraviolet damage endonuclease. Structure 2007; 15:1316-24. [PMID: 17937920 DOI: 10.1016/j.str.2007.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 05/31/2007] [Accepted: 05/31/2007] [Indexed: 11/24/2022]
Abstract
The ultraviolet damage endonuclease (UVDE) performs the initial step in an alternative excision repair pathway of UV-induced DNA damage, nicking immediately adjacent to the 5' phosphate of the damaged nucleotides. Unique for a single-protein DNA repair endonuclease, it can detect different types of damage. Here we show that Thermus thermophilus UVDE shares some essential structural features with Endo IV, an enzyme from the base excision repair pathway that exclusively nicks at abasic sites. A comparison between the structures indicates how DNA is bound by UVDE, how UVDE may recognize damage, and which of its residues are involved in catalysis. Furthermore, the comparison suggests an elegant explanation of UVDE's potential to recognize different types of damage. Incision assays including point mutants of UVDE confirmed the relevance of these conclusions.
Collapse
|
12
|
Fraser JLA, Neill E, Davey S. Fission yeast Uve1 and Apn2 function in distinct oxidative damage repair pathways in vivo. DNA Repair (Amst) 2004; 2:1253-67. [PMID: 14599746 DOI: 10.1016/j.dnarep.2003.08.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In Schizosaccharomyces pombe, the endonuclease Uve1 functions as the first step in an alternate UV photo-product repair pathway that is distinct from nucleotide excision repair (NER). Based upon the broad substrate specificity of Uve1 in vitro, and the observation that Uve1 mutants accumulate spontaneous mutations at an elevated rate in vivo, we and others have hypothesized that this protein might have a function in a mutation avoidance pathway other than UV photo-product repair. We show here that fission yeast Uve1 also functions in oxidative damage repair in vivo. We have determined the spectrum of spontaneous mutations that arise in uve1 null (uve1 degrees ) cells and have observed that both G-->T(C-->A) and T-->G(A-->C) transversions occur at an increased rate relative to wildtype cells. These mutations are indicative of unrepaired oxidative DNA damage and are very similar to the mutation spectrum observed in 8-oxoguanine glycosylase (OGG1) mutants in Saccharomyces cerevisiae. We have generated an apn2 null (apn2 degrees ) strain and shown that it is mildly sensitive to H(2)O(2). Furthermore we have also shown that apn2 degrees cells have an elevated rate of spontaneous mutation that is similar to uve1 degrees. The phenotype of apn2 degrees uve1 degrees double mutants indicates that these genes define distinct spontaneous mutation avoidance pathways. While uve1 degrees cells show only a modest sensitivity to the oxidizing agent hydrogen peroxide (H(2)O(2)), both uve1 degrees and apn2 degrees cells also display a marked increased in mutation rate following exposure to H(2)O(2) doses. Collectively these data demonstrate that Uve1 is a component of multiple alternate repair pathways in fission yeast and suggest a possible role for Uve1 in a general alternate incision repair pathway in eukaryotes.
Collapse
Affiliation(s)
- J Lee A Fraser
- Department of Pathology, Queen's University, ON, Kingston, Canada K7L 3N6
| | | | | |
Collapse
|
13
|
Ribar B, Izumi T, Mitra S. The major role of human AP-endonuclease homolog Apn2 in repair of abasic sites in Schizosaccharomyces pombe. Nucleic Acids Res 2004; 32:115-26. [PMID: 14704348 PMCID: PMC373264 DOI: 10.1093/nar/gkh151] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The abasic (AP) sites, the major mutagenic and cytotoxic genomic lesions, induced directly by oxidative stress and indirectly after excision of damaged bases by DNA glycosylases, are repaired by AP-endonucleases (APEs). Among two APEs in Saccharomyces cerevisiae, Apn1 provides the major APE activity, and Apn2, the ortholog of the mammalian APE, provides back-up activity. We have cloned apn1 and apn2 genes of Schizosaccharomyces pombe, and have shown that inactivation of Apn2 and not Apn1 sensitizes this fission yeast to alkylation and oxidative damage-inducing agents, which is further enhanced by Apn1 inactivation. We also show that Uve1, present in S.pombe but not in S.cerevisiae, provides the back-up APE activity together with Apn1. We confirmed the presence of APE activity in recombinant Apn2 and in crude cell extracts. Thus S.pombe is distinct from S.cerevisiae, and is similar to mammalian cells in having Apn2 as the major APE.
Collapse
Affiliation(s)
- Balazs Ribar
- Sealy Center for Molecular Science, University of Texas Medical Branch, 6.148 Medical Research Building, Galveston, TX 77555, USA
| | | | | |
Collapse
|
14
|
Earl AM, Rankin SK, Kim KP, Lamendola ON, Battista JR. Genetic evidence that the uvsE gene product of Deinococcus radiodurans R1 is a UV damage endonuclease. J Bacteriol 2002; 184:1003-9. [PMID: 11807060 PMCID: PMC134819 DOI: 10.1128/jb.184.4.1003-1009.2002] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An in vitro transposition system, developed to facilitate gene disruption in Deinococcus radiodurans R1, has been used to inactivate the gene designated dr1819 in uvrA-1(+) and uvrA-1 backgrounds. dr1819 encodes a protein with homology to a UV DNA damage endonuclease expressed by Schizosaccharomyces pombe. Interruption of dr1819 greatly sensitizes the uvrA-1 strain but not the uvrA-1(+) strain to UV light, indicating that the dr1819 gene product is a component in a DNA repair pathway that can compensate for the loss of nucleotide excision repair in this species. Clones of dr1819 will restore UV resistance to UVS78, a uvrA-1 uvsE strain, indicating that dr1819 and uvsE are the same locus.
Collapse
Affiliation(s)
- Ashlee M Earl
- Department of Biological Sciences, Louisiana State University and A & M College, Baton Rouge, Louisiana 70803, USA
| | | | | | | | | |
Collapse
|
15
|
Kunz C, Fleck O. Role of the DNA repair nucleases Rad13, Rad2 and Uve1 of Schizosaccharomyces pombe in mismatch correction. J Mol Biol 2001; 313:241-53. [PMID: 11800554 DOI: 10.1006/jmbi.2001.5054] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Repair of mismatched DNA occurs mainly by the long-patch mismatch repair (MMR) pathway, requiring Msh2 and Pms1. In Schizosaccharomyces pombe mismatches can be repaired by a short-patch repair system, containing nucleotide excision repair (NER) factors. We studied mismatch correction efficiency in cells with inactivated DNA repair nucleases Rad13, Rad2 or Uve1 in MMR proficient and deficient background. Rad13 incises 3' of damaged DNA during NER. Rad2 has a function in the Uve1-dependent repair of DNA damages and in replication. Loss of Rad13 caused a strong reduction of short-patch processing of mismatches formed during meiotic recombination. Mitotic mutation rates were increased, but not to the same extent as in the NER mutant swi10, which is defective in 5' incision. The difference might be caused by an additional role of Rad13 in base excision repair or due to partial redundancy with other 3' endonucleases. Meiotic mismatch repair was not or only slightly affected in rad2 and uve1 mutants. In addition, inactivation of uve1 caused only weak effects on mutation avoidance. Mutation rates were elevated when rad2 was mutated, but not further increased in swi10 rad2 and rad13 rad2 double mutants, indicating an epistatic relationship. However, the mutation spectra of rad2 were different from that of swi10 and rad13. Thus, the function of Rad2 in mutation avoidance is rather independent of NER. rad13, swi10 and rad2, but not uve1 mutants were sensitive to the DNA-damaging agent methyl methane sulphonate. Cell survival was further reduced in the double mutants swi10 rad2, rad13 rad2 and, surprisingly, swi10 rad13. These data confirm that NER and Rad2 act in distinct damage repair pathways and further indicate that the function of Rad13 in repair of alkylated bases is partially independent of NER.
Collapse
Affiliation(s)
- C Kunz
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, Bern, CH-3012, Switzerland
| | | |
Collapse
|
16
|
Abstract
Mismatch repair (MMR) systems play a central role in promoting genetic stability by repairing DNA replication errors, inhibiting recombination between non-identical DNA sequences and participating in responses to DNA damage. The discovery of a link between human cancer and MMR defects has led to an explosion of research on eukaryotic MMR. The key proteins in MMR are highly conserved from bacteria to mammals, and this conservation has been critical for defining the components of eukaryotic MMR systems. In eukaryotes, there are multiple homologs of the key bacterial MutS and MutL MMR proteins, and these homologs form heterodimers that have discrete roles in MMR-related processes. This review describes the genetic and biochemical approaches used to study MMR, and summarizes the diverse roles that MMR proteins play in maintaining genetic stability.
Collapse
Affiliation(s)
- B D Harfe
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | | |
Collapse
|
17
|
Alleva JL, Doetsch PW. The nature of the 5'-terminus is a major determinant for DNA processing by Schizosaccharomyces pombe Rad2p, a FEN-1 family nuclease. Nucleic Acids Res 2000; 28:2893-901. [PMID: 10908351 PMCID: PMC102672 DOI: 10.1093/nar/28.15.2893] [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: 11/15/2022] Open
Abstract
The nuclease activity of FEN-1 is essential for both DNA replication and repair. Intermediate DNA products formed during these processes possess a variety of structures and termini. We have previously demonstrated that the 5'-->3' exonuclease activity of the Schizosaccharomyces pombe FEN-1 protein Rad2p requires a 5'-phosphoryl moiety to efficiently degrade a nick-containing substrate in a reconstituted alternative excision repair system. Here we report the effect of different 5'-terminal moieties of a variety of DNA substrates on Rad2p activity. We also show that Rad2p possesses a 5'-->3' single-stranded exonuclease activity, similar to Saccharomyces cerevisiae Rad27p and phage T5 5'-->3' exonuclease (also a FEN-1 homolog). FEN-1 nucleases have been associated with the base excision repair pathway, specifically processing cleaved abasic sites. Because several enzymes cleave abasic sites through different mechanisms resulting in different 5'-termini, we investigated the ability of Rad2p to process several different types of cleaved abasic sites. With varying efficiency, Rad2p degrades the products of an abasic site cleaved by Escherichia coli endonuclease III and endonuclease IV (prototype AP endonucleases) and S.POMBE: Uve1p. These results provide important insights into the roles of Rad2p in DNA repair processes in S.POMBE:
Collapse
Affiliation(s)
- J L Alleva
- Department of Biochemistry, Graduate Program in Genetics and Molecular Biology and Division of Cancer Biology, Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | |
Collapse
|
18
|
Abstract
Recombination events between non-identical sequences most often involve heteroduplex DNA intermediates that are subjected to mismatch repair. The well-characterized long-patch mismatch repair process, controlled in eukaryotes by bacterial MutS and MutL orthologs, is the major system involved in repair of mispaired bases. Here we present evidence for an alternative short-patch mismatch repair pathway that operates on a broad spectrum of mismatches. In msh2 mutants lacking the long-patch repair system, sequence analysis of recombination tracts resulting from exchanges between similar but non-identical (homeologous) parental DNAs showed the occurrence of short-patch repair events that can involve <12 nucleotides. Such events were detected both in mitotic and in meiotic recombinants. Confirming the existence of a distinct short-patch repair activity, we found in a recombination assay involving homologous alleles that closely spaced mismatches are repaired independently with high efficiency in cells lacking MSH2 or PMS1. We show that this activity does not depend on genes required for nucleotide excision repair and thus differs from the short-patch mismatch repair described in Schizosaccharomyces pombe.
Collapse
Affiliation(s)
- E Coïc
- Commissariat à l'Energie Atomique, UMR217 CEA/CNRS, DSV/DRR, Bat. 05, BP6, 92265 Fontenay-aux-Roses, France
| | | | | |
Collapse
|
19
|
Abstract
This review is concerned with repair and tolerance of UV damage in the fission yeast, Schizosaccharomyces pombe and with the differences between Sch. pombe and budding yeast, Saccharomyces cerevisiae in their response to UV irradiation. Sch. pombe is not as sensitive to ultra-violet radiation as Sac. cerevisiae nor are any of its mutants as sensitive as the most sensitive Sac. cerevisiae mutants. This can be explained in part by the fact that Sch. pombe, unlike budding yeast or mammalian cells, has an extra pathway (UVER) for excision of UV photoproducts in addition to nucleotide excision repair (NER). However, even in mutants lacking this additional pathway, there are significant differences between the two yeasts. Sch. pombe mutants that lack the alternative pathway are still more UV-resistant than wild-type Sac. cerevisiae; recombination mutants are significantly UV sensitive (unlike their Sac. cerevisiae equivalents); mutants lacking the second pathway are sensitized to UV by caffeine; and checkpoint mutants are relatively more sensitive than the budding yeast equivalents. In addition, Sch. pombe has no photolyase. Thus, the response to UV in the two yeasts has a number of significant differences, which are not accounted for entirely by the existence of two alternative excision repair pathways. The long G2 in Sch. pombe, its well-developed recombination pathways and efficient cell cycle checkpoints are all significant components in survival of UV damage.
Collapse
Affiliation(s)
- S J McCready
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU, Oxford, UK.
| | | | | |
Collapse
|
20
|
Abstract
Mismatch repair (MMR) proteins play a critical role in maintaining the mitotic stability of eukaryotic genomes. MMR proteins repair errors made during DNA replication and in their absence, mutations accumulate at elevated rates. In addition, MMR proteins inhibit recombination between non-identical DNA sequences, and hence prevent genome rearrangements resulting from interactions between repetitive elements. This review provides an overview of the anti-mutator and anti-recombination functions of MMR proteins in the yeast Saccharomyces cerevisiae.
Collapse
Affiliation(s)
- B D Harfe
- Department of Biology, Emory University, 1510 Clifton Road, Atlanta, GA 30322, USA
| | | |
Collapse
|
21
|
Memisoglu A, Samson L. Contribution of base excision repair, nucleotide excision repair, and DNA recombination to alkylation resistance of the fission yeast Schizosaccharomyces pombe. J Bacteriol 2000; 182:2104-12. [PMID: 10735851 PMCID: PMC111257 DOI: 10.1128/jb.182.8.2104-2112.2000] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DNA damage is unavoidable, and organisms across the evolutionary spectrum possess DNA repair pathways that are critical for cell viability and genomic stability. To understand the role of base excision repair (BER) in protecting eukaryotic cells against alkylating agents, we generated Schizosaccharomyces pombe strains mutant for the mag1 3-methyladenine DNA glycosylase gene. We report that S. pombe mag1 mutants have only a slightly increased sensitivity to methylation damage, suggesting that Mag1-initiated BER plays a surprisingly minor role in alkylation resistance in this organism. We go on to show that other DNA repair pathways play a larger role than BER in alkylation resistance. Mutations in genes involved in nucleotide excision repair (rad13) and recombinational repair (rhp51) are much more alkylation sensitive than mag1 mutants. In addition, S. pombe mutant for the flap endonuclease rad2 gene, whose precise function in DNA repair is unclear, were also more alkylation sensitive than mag1 mutants. Further, mag1 and rad13 interact synergistically for alkylation resistance, and mag1 and rhp51 display a surprisingly complex genetic interaction. A model for the role of BER in the generation of alkylation-induced DNA strand breaks in S. pombe is discussed.
Collapse
Affiliation(s)
- A Memisoglu
- Department of Cancer Cell Biology, Harvard School of Public Health, Boston, Massachusetts 02115, USA
| | | |
Collapse
|