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Yu Y, Wang X, Fox J, Li Q, Yu Y, Hastings PJ, Chen K, Ira G. RPA and Rad27 limit templated and inverted insertions at DNA breaks. bioRxiv 2024:2024.03.07.583931. [PMID: 38496432 PMCID: PMC10942419 DOI: 10.1101/2024.03.07.583931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Formation of templated insertions at DNA double-strand breaks (DSBs) is very common in cancer cells. The mechanisms and enzymes regulating these events are largely unknown. Here, we investigated templated insertions in yeast at DSBs using amplicon sequencing across a repaired locus. We document very short (most ∼5-34 bp), templated inverted duplications at DSBs. They are generated through a foldback mechanism that utilizes microhomologies adjacent to the DSB. Enzymatic requirements suggest a hybrid mechanism wherein one end requires Polδ-mediated synthesis while the other end is captured by nonhomologous end joining (NHEJ). This process is exacerbated in mutants with low levels or mutated RPA ( rtt105 Δ; rfa1 -t33) or extensive resection mutant ( sgs1 Δ exo1 Δ). Templated insertions from various distant genomic locations also increase in these mutants as well as in rad27 Δ and originate from fragile regions of the genome. Among complex insertions, common events are insertions of two sequences, originating from the same locus and with inverted orientation. We propose that these inversions are also formed by microhomology-mediated template switching. Taken together, we propose that a shortage of RPA typical in cancer cells is one possible factor stimulating the formation of templated insertions.
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Yu Y, Wang X, Fox J, Yu R, Thakre P, McCauley B, Nikoloutsos N, Li Q, Hastings PJ, Dang W, Chen K, Ira G. Yeast EndoG prevents genome instability by degrading cytoplasmic DNA. bioRxiv 2023:2023.12.13.571550. [PMID: 38168242 PMCID: PMC10760121 DOI: 10.1101/2023.12.13.571550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
In metazoans release of mitochondrial DNA or retrotransposon cDNA to cytoplasm can cause sterile inflammation and disease. Cytoplasmic nucleases degrade these DNA species to limit inflammation. It remains unknown whether degradation these DNA also prevents nuclear genome instability. To address this question, we decided to identify the nuclease regulating transfer of these cytoplasmic DNA species to the nucleus. We used an amplicon sequencing-based method in yeast enabling analysis of millions of DSB repair products. Nu clear mt DNA (NUMTs) and retrotransposon cDNA insertions increase dramatically in nondividing stationary phase cells. Yeast EndoG (Nuc1) nuclease limits insertions of cDNA and transfer of very long mtDNA (>10 kb) that forms unstable circles or rarely insert in the genome, but it promotes formation of short NUMTs (∼45-200 bp). Nuc1 also regulates transfer of cytoplasmic DNA to nucleus in aging or during meiosis. We propose that Nuc1 preserves genome stability by degrading retrotransposon cDNA and long mtDNA, while short NUMTs can originate from incompletely degraded mtDNA. This work suggests that nucleases eliminating cytoplasmic DNA play a role in preserving genome stability.
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Zhai Y, Minnick PJ, Pribis JP, Garcia-Villada L, Hastings PJ, Herman C, Rosenberg SM. ppGpp and RNA-polymerase backtracking guide antibiotic-induced mutable gambler cells. Mol Cell 2023; 83:1298-1310.e4. [PMID: 36965481 DOI: 10.1016/j.molcel.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/14/2022] [Accepted: 03/02/2023] [Indexed: 03/27/2023]
Abstract
Antibiotic resistance is a global health threat and often results from new mutations. Antibiotics can induce mutations via mechanisms activated by stress responses, which both reveal environmental cues of mutagenesis and are weak links in mutagenesis networks. Network inhibition could slow the evolution of resistance during antibiotic therapies. Despite its pivotal importance, few identities and fewer functions of stress responses in mutagenesis are clear. Here, we identify the Escherichia coli stringent starvation response in fluoroquinolone-antibiotic ciprofloxacin-induced mutagenesis. Binding of response-activator ppGpp to RNA polymerase (RNAP) at two sites leads to an antibiotic-induced mutable gambler-cell subpopulation. Each activates a stress response required for mutagenic DNA-break repair: surprisingly, ppGpp-site-1-RNAP triggers the DNA-damage response, and ppGpp-site-2-RNAP induces σS-response activity. We propose that RNAP regulates DNA-damage processing in transcribed regions. The data demonstrate a critical node in ciprofloxacin-induced mutagenesis, imply RNAP-regulation of DNA-break repair, and identify promising targets for resistance-resisting drugs.
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Affiliation(s)
- Yin Zhai
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - P J Minnick
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - John P Pribis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - Libertad Garcia-Villada
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christophe Herman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Susan M Rosenberg
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Systems, Synthetic, and Physical Biology Program, Rice University, Houston, TX 77030, USA.
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4
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Du H, Jolly A, Grochowski CM, Yuan B, Dawood M, Jhangiani SN, Li H, Muzny D, Fatih JM, Coban-Akdemir Z, Carlin ME, Scheuerle AE, Witzl K, Posey JE, Pendleton M, Harrington E, Juul S, Hastings PJ, Bi W, Gibbs RA, Sedlazeck FJ, Lupski JR, Carvalho CMB, Liu P. The multiple de novo copy number variant (MdnCNV) phenomenon presents with peri-zygotic DNA mutational signatures and multilocus pathogenic variation. Genome Med 2022; 14:122. [PMID: 36303224 PMCID: PMC9609164 DOI: 10.1186/s13073-022-01123-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 10/10/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The multiple de novo copy number variant (MdnCNV) phenotype is described by having four or more constitutional de novo CNVs (dnCNVs) arising independently throughout the human genome within one generation. It is a rare peri-zygotic mutational event, previously reported to be seen once in every 12,000 individuals referred for genome-wide chromosomal microarray analysis due to congenital abnormalities. These rare families provide a unique opportunity to understand the genetic factors of peri-zygotic genome instability and the impact of dnCNV on human diseases. METHODS Chromosomal microarray analysis (CMA), array-based comparative genomic hybridization, short- and long-read genome sequencing (GS) were performed on the newly identified MdnCNV family to identify de novo mutations including dnCNVs, de novo single-nucleotide variants (dnSNVs), and indels. Short-read GS was performed on four previously published MdnCNV families for dnSNV analysis. Trio-based rare variant analysis was performed on the newly identified individual and four previously published MdnCNV families to identify potential genetic etiologies contributing to the peri-zygotic genomic instability. Lin semantic similarity scores informed quantitative human phenotype ontology analysis on three MdnCNV families to identify gene(s) driving or contributing to the clinical phenotype. RESULTS In the newly identified MdnCNV case, we revealed eight de novo tandem duplications, each ~ 1 Mb, with microhomology at 6/8 breakpoint junctions. Enrichment of de novo single-nucleotide variants (SNV; 6/79) and de novo indels (1/12) was found within 4 Mb of the dnCNV genomic regions. An elevated post-zygotic SNV mutation rate was observed in MdnCNV families. Maternal rare variant analyses identified three genes in distinct families that may contribute to the MdnCNV phenomenon. Phenotype analysis suggests that gene(s) within dnCNV regions contribute to the observed proband phenotype in 3/3 cases. CNVs in two cases, a contiguous gene duplication encompassing PMP22 and RAI1 and another duplication affecting NSD1 and SMARCC2, contribute to the clinically observed phenotypic manifestations. CONCLUSIONS Characteristic features of dnCNVs reported here are consistent with a microhomology-mediated break-induced replication (MMBIR)-driven mechanism during the peri-zygotic period. Maternal genetic variants in DNA repair genes potentially contribute to peri-zygotic genomic instability. Variable phenotypic features were observed across a cohort of three MdnCNV probands, and computational quantitative phenotyping revealed that two out of three had evidence for the contribution of more than one genetic locus to the proband's phenotype supporting the hypothesis of de novo multilocus pathogenic variation (MPV) in those families.
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Affiliation(s)
- Haowei Du
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Angad Jolly
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Christopher M Grochowski
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Bo Yuan
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Baylor Genetics Laboratory, Houston, TX, 77021, USA
- Seattle Children's Hospital, Seattle, WA, 98105, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Moez Dawood
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - He Li
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Donna Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jawid M Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Zeynep Coban-Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Mary Esther Carlin
- Division of Genetics and Metabolism, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Angela E Scheuerle
- Division of Genetics and Metabolism, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Division of Genetics Diagnostics, Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Karin Witzl
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, 1000, Ljubljana, Slovenia
- Medical Faculty, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | | | | | - Sissel Juul
- Oxford Nanopore Technologies Inc, New York, NY, 10013, USA
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, BCM, Houston, TX, 77030, USA
| | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Baylor Genetics Laboratory, Houston, TX, 77021, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Fritz J Sedlazeck
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Texas Children's Hospital, Houston, TX, 77030, USA.
| | - Claudia M B Carvalho
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Pacific Northwest Research Institute, 720 Broadway, Seattle, WA, 98122, USA.
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Baylor Genetics Laboratory, Houston, TX, 77021, USA.
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5
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Mei Q, Fitzgerald DM, Liu J, Xia J, Pribis JP, Zhai Y, Nehring RB, Paiano J, Li H, Nussenzweig A, Hastings PJ, Rosenberg SM. Two mechanisms of chromosome fragility at replication-termination sites in bacteria. Sci Adv 2021; 7:eabe2846. [PMID: 34144978 PMCID: PMC8213236 DOI: 10.1126/sciadv.abe2846] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 05/06/2021] [Indexed: 05/12/2023]
Abstract
Chromosomal fragile sites are implicated in promoting genome instability, which drives cancers and neurological diseases. Yet, the causes and mechanisms of chromosome fragility remain speculative. Here, we identify three spontaneous fragile sites in the Escherichia coli genome and define their DNA damage and repair intermediates at high resolution. We find that all three sites, all in the region of replication termination, display recurrent four-way DNA or Holliday junctions (HJs) and recurrent DNA breaks. Homology-directed double-strand break repair generates the recurrent HJs at all of these sites; however, distinct mechanisms of DNA breakage are implicated: replication fork collapse at natural replication barriers and, unexpectedly, frequent shearing of unsegregated sister chromosomes at cell division. We propose that mechanisms such as both of these may occur ubiquitously, including in humans, and may constitute some of the earliest events that underlie somatic cell mosaicism, cancers, and other diseases of genome instability.
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Affiliation(s)
- Qian Mei
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Systems, Synthetic and Physical Biology Program, Rice University, Houston, TX 77030, USA
| | - Devon M Fitzgerald
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Jingjing Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Jun Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - John P Pribis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Yin Zhai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Ralf B Nehring
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Jacob Paiano
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Heyuan Li
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Andre Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Systems, Synthetic and Physical Biology Program, Rice University, Houston, TX 77030, USA
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6
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Pribis JP, García-Villada L, Zhai Y, Lewin-Epstein O, Wang AZ, Liu J, Xia J, Mei Q, Fitzgerald DM, Bos J, Austin RH, Herman C, Bates D, Hadany L, Hastings PJ, Rosenberg SM. Gamblers: An Antibiotic-Induced Evolvable Cell Subpopulation Differentiated by Reactive-Oxygen-Induced General Stress Response. Mol Cell 2019; 74:785-800.e7. [PMID: 30948267 PMCID: PMC6553487 DOI: 10.1016/j.molcel.2019.02.037] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 01/17/2019] [Accepted: 02/26/2019] [Indexed: 11/23/2022]
Abstract
Antibiotics can induce mutations that cause antibiotic resistance. Yet, despite their importance, mechanisms of antibiotic-promoted mutagenesis remain elusive. We report that the fluoroquinolone antibiotic ciprofloxacin (cipro) induces mutations by triggering transient differentiation of a mutant-generating cell subpopulation, using reactive oxygen species (ROS). Cipro-induced DNA breaks activate the Escherichia coli SOS DNA-damage response and error-prone DNA polymerases in all cells. However, mutagenesis is limited to a cell subpopulation in which electron transfer together with SOS induce ROS, which activate the sigma-S (σS) general-stress response, which allows mutagenic DNA-break repair. When sorted, this small σS-response-"on" subpopulation produces most antibiotic cross-resistant mutants. A U.S. Food and Drug Administration (FDA)-approved drug prevents σS induction, specifically inhibiting antibiotic-promoted mutagenesis. Further, SOS-inhibited cell division, which causes multi-chromosome cells, promotes mutagenesis. The data support a model in which within-cell chromosome cooperation together with development of a "gambler" cell subpopulation promote resistance evolution without risking most cells.
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Affiliation(s)
- John P Pribis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - Libertad García-Villada
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yin Zhai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ohad Lewin-Epstein
- Department of Molecular Biology and Ecology of Plants, Tel-Aviv University, Tel-Aviv, Israel
| | - Anthony Z Wang
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77030, USA
| | - Jingjing Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jun Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qian Mei
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Systems, Synthetic, and Physical Biology Program, Rice University, Houston, TX 77030, USA
| | - Devon M Fitzgerald
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Julia Bos
- Department of Physics, Princeton University, Princeton, NJ 08544-0708, USA; Lewis Sigler Institute, Princeton University, Princeton, NJ 08544-0708, USA
| | - Robert H Austin
- Lewis Sigler Institute, Princeton University, Princeton, NJ 08544-0708, USA
| | - Christophe Herman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Bates
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lilach Hadany
- Department of Molecular Biology and Ecology of Plants, Tel-Aviv University, Tel-Aviv, Israel
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77030, USA; Systems, Synthetic, and Physical Biology Program, Rice University, Houston, TX 77030, USA.
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7
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Affiliation(s)
- Philip J Hastings
- Department of Molecular and Human Genetics and the Dan L. Duncan Comprehensive Cancer Center at Baylor College of Medicine, Houston, TX, USA.
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics and the Dan L. Duncan Comprehensive Cancer Center at Baylor College of Medicine, Houston, TX, USA. .,Departments of Biochemistry and Molecular Biology, and Molecular Virology and Microbiology at Baylor College of Medicine, Houston, TX, USA.
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8
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Beck CR, Carvalho CMB, Akdemir ZC, Sedlazeck FJ, Song X, Meng Q, Hu J, Doddapaneni H, Chong Z, Chen ES, Thornton PC, Liu P, Yuan B, Withers M, Jhangiani SN, Kalra D, Walker K, English AC, Han Y, Chen K, Muzny DM, Ira G, Shaw CA, Gibbs RA, Hastings PJ, Lupski JR. Megabase Length Hypermutation Accompanies Human Structural Variation at 17p11.2. Cell 2019; 176:1310-1324.e10. [PMID: 30827684 PMCID: PMC6438178 DOI: 10.1016/j.cell.2019.01.045] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 11/06/2018] [Accepted: 01/25/2019] [Indexed: 01/16/2023]
Abstract
DNA rearrangements resulting in human genome structural variants (SVs) are caused by diverse mutational mechanisms. We used long- and short-read sequencing technologies to investigate end products of de novo chromosome 17p11.2 rearrangements and query the molecular mechanisms underlying both recurrent and non-recurrent events. Evidence for an increased rate of clustered single-nucleotide variant (SNV) mutation in cis with non-recurrent rearrangements was found. Indel and SNV formation are associated with both copy-number gains and losses of 17p11.2, occur up to ∼1 Mb away from the breakpoint junctions, and favor C > G transversion substitutions; results suggest that single-stranded DNA is formed during the genesis of the SV and provide compelling support for a microhomology-mediated break-induced replication (MMBIR) mechanism for SV formation. Our data show an additional mutational burden of MMBIR consisting of hypermutation confined to the locus and manifesting as SNVs and indels predominantly within genes.
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Affiliation(s)
- Christine R Beck
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | | | - Zeynep C Akdemir
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | | | - Xiaofei Song
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Qingchang Meng
- Human Genome Sequencing Center, BCM, Houston, TX 77030, USA
| | - Jianhong Hu
- Human Genome Sequencing Center, BCM, Houston, TX 77030, USA
| | | | - Zechen Chong
- Department of Genetics and the Informatics Institute, the University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Edward S Chen
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Philip C Thornton
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Bo Yuan
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Marjorie Withers
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | | | - Divya Kalra
- Human Genome Sequencing Center, BCM, Houston, TX 77030, USA
| | | | - Adam C English
- Human Genome Sequencing Center, BCM, Houston, TX 77030, USA
| | - Yi Han
- Human Genome Sequencing Center, BCM, Houston, TX 77030, USA
| | - Ken Chen
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, BCM, Houston, TX 77030, USA
| | - Grzegorz Ira
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Chad A Shaw
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Human Genome Sequencing Center, BCM, Houston, TX 77030, USA
| | - P J Hastings
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, BCM, Houston, TX 77030, USA.
| | - James R Lupski
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Human Genome Sequencing Center, BCM, Houston, TX 77030, USA; Department of Pediatrics, BCM, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, BCM, Houston, TX 77030, USA.
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9
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Xia J, Chiu LY, Nehring RB, Bravo Núñez MA, Mei Q, Perez M, Zhai Y, Fitzgerald DM, Pribis JP, Wang Y, Hu CW, Powell RT, LaBonte SA, Jalali A, Matadamas Guzmán ML, Lentzsch AM, Szafran AT, Joshi MC, Richters M, Gibson JL, Frisch RL, Hastings PJ, Bates D, Queitsch C, Hilsenbeck SG, Coarfa C, Hu JC, Siegele DA, Scott KL, Liang H, Mancini MA, Herman C, Miller KM, Rosenberg SM. Bacteria-to-Human Protein Networks Reveal Origins of Endogenous DNA Damage. Cell 2019; 176:127-143.e24. [PMID: 30633903 PMCID: PMC6344048 DOI: 10.1016/j.cell.2018.12.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 09/05/2018] [Accepted: 12/05/2018] [Indexed: 12/21/2022]
Abstract
DNA damage provokes mutations and cancer and results from external carcinogens or endogenous cellular processes. However, the intrinsic instigators of endogenous DNA damage are poorly understood. Here, we identify proteins that promote endogenous DNA damage when overproduced: the DNA "damage-up" proteins (DDPs). We discover a large network of DDPs in Escherichia coli and deconvolute them into six function clusters, demonstrating DDP mechanisms in three: reactive oxygen increase by transmembrane transporters, chromosome loss by replisome binding, and replication stalling by transcription factors. Their 284 human homologs are over-represented among known cancer drivers, and their RNAs in tumors predict heavy mutagenesis and a poor prognosis. Half of the tested human homologs promote DNA damage and mutation when overproduced in human cells, with DNA damage-elevating mechanisms like those in E. coli. Our work identifies networks of DDPs that provoke endogenous DNA damage and may reveal DNA damage-associated functions of many human known and newly implicated cancer-promoting proteins.
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Affiliation(s)
- Jun Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - Li-Ya Chiu
- Department of Molecular Biosciences, LIVESTRONG Cancer Institute of the Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA
| | - Ralf B Nehring
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - María Angélica Bravo Núñez
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qian Mei
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Systems, Synthetic and Physical Biology Program, Rice University, Houston, TX 77030, USA
| | - Mercedes Perez
- Department of Molecular Biosciences, LIVESTRONG Cancer Institute of the Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA
| | - Yin Zhai
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Devon M Fitzgerald
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - John P Pribis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yumeng Wang
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, TX 77030, USA; Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Chenyue W Hu
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Reid T Powell
- Institute of Biosciences and Technology, Texas A&M University, Houston, TX 77030, USA
| | - Sandra A LaBonte
- Department of Biochemistry and Biophysics, Texas A&M University and Texas AgriLife Research, College Station, TX 77843, USA
| | - Ali Jalali
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neurosurgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meztli L Matadamas Guzmán
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alfred M Lentzsch
- Department of Molecular Biosciences, LIVESTRONG Cancer Institute of the Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA
| | - Adam T Szafran
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mohan C Joshi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Megan Richters
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Janet L Gibson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ryan L Frisch
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - David Bates
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christine Queitsch
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Susan G Hilsenbeck
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Cristian Coarfa
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - James C Hu
- Department of Biochemistry and Biophysics, Texas A&M University and Texas AgriLife Research, College Station, TX 77843, USA
| | - Deborah A Siegele
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - Kenneth L Scott
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - Han Liang
- Graduate Program in Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, TX 77030, USA; Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Michael A Mancini
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christophe Herman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Kyle M Miller
- Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Biosciences, LIVESTRONG Cancer Institute of the Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA.
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA; Systems, Synthetic and Physical Biology Program, Rice University, Houston, TX 77030, USA.
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10
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Kotlajich MV, Xia J, Zhai Y, Lin HY, Bradley CC, Shen X, Mei Q, Wang AZ, Lynn EJ, Shee C, Chen LT, Li L, Miller KM, Herman C, Hastings PJ, Rosenberg SM. Fluorescent fusions of the N protein of phage Mu label DNA damage in living cells. DNA Repair (Amst) 2018; 72:86-92. [PMID: 30268364 PMCID: PMC6287932 DOI: 10.1016/j.dnarep.2018.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 09/09/2018] [Accepted: 09/10/2018] [Indexed: 01/06/2023]
Abstract
The N protein of phage Mu was indicated from studies in Escherichia coli to hold linear Mu chromosomes in a circular conformation by non-covalent association, and thus suggested potentially to bind DNA double-stranded ends. Because of its role in association with linear Mu DNA, we tested whether fluorescent-protein fusions to N might provide a useful tool for labeling DNA damage including double-strand break (DSB) ends in single cells. We compared N-GFP with a biochemically well documented DSB-end binding protein, the Gam protein of phage Mu, also fused to GFP. We find that N-GFP produced in live E. coli forms foci in response to DNA damage induced by radiomimetic drug phleomycin, indicating that it labels damaged DNA. N-GFP also labels specific DSBs created enzymatically by I-SceI double-strand endonuclease, and by X-rays, with the numbers of foci corresponding with the numbers of DSBs generated, indicating DSB labeling. However, whereas N-GFP forms about half as many foci as GamGFP with phleomycin, its labeling of I-SceI- and X-ray-induced DSBs is far less efficient than that of GamGFP. The data imply that N-GFP binds and labels DNA damage including DSBs, but may additionally label phleomycin-induced non-DSB damage, with which DSB-specific GamGFP does not interact. The data indicate that N-GFP labels DNA damage, and may be useful for general, not DSB-specific, DNA-damage detection.
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Affiliation(s)
- Matthew V Kotlajich
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jun Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Yin Zhai
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Hsin-Yu Lin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Catherine C Bradley
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas 77030, USA; Robert and Janice McNair Foundation/McNair Medical Institute M.D./Ph.D. Scholars Program, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Xi Shen
- Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Qian Mei
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA; Systems, Synthetic and Physical Biology Program, Rice University, Houston, Texas 77030, USA
| | - Anthony Z Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Erica J Lynn
- Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Chandan Shee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Li-Tzu Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Lei Li
- Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Kyle M Miller
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712 USA
| | - Christophe Herman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030, USA; Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA; Systems, Synthetic and Physical Biology Program, Rice University, Houston, Texas 77030, USA.
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11
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Abstract
Genomic instability underlies many cancers and generates genetic variation that drives cancer initiation, progression, and therapy resistance. In contrast with classical assumptions that mutations occur purely stochastically at constant, gradual rates, microbes, plants, flies, and human cancer cells possess mechanisms of mutagenesis that are upregulated by stress responses. These generate transient, genetic-diversity bursts that can propel evolution, specifically when cells are poorly adapted to their environments-that is, when stressed. We review molecular mechanisms of stress-response-dependent (stress-induced) mutagenesis that occur from bacteria to cancer, and are activated by starvation, drugs, hypoxia, and other stressors. We discuss mutagenic DNA break repair in Escherichia coli as a model for mechanisms in cancers. The temporal regulation of mutagenesis by stress responses and spatial restriction in genomes are common themes across the tree of life. Both can accelerate evolution, including the evolution of cancers. We discuss possible anti-evolvability drugs, aimed at targeting mutagenesis and other variation generators, that could be used to delay the evolution of cancer progression and therapy resistance.
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Affiliation(s)
- Devon M Fitzgerald
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston Texas 77030
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston Texas 77030
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas 77030
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12
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Moore JM, Magnan D, Mojica AK, Núñez MAB, Bates D, Rosenberg SM, Hastings PJ. Roles of Nucleoid-Associated Proteins in Stress-Induced Mutagenic Break Repair in Starving Escherichia coli. Genetics 2015; 201:1349-62. [PMID: 26500258 PMCID: PMC4676537 DOI: 10.1534/genetics.115.178970] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/18/2015] [Indexed: 01/02/2023] Open
Abstract
The mutagenicity of DNA double-strand break repair in Escherichia coli is controlled by DNA-damage (SOS) and general (RpoS) stress responses, which let error-prone DNA polymerases participate, potentially accelerating evolution during stress. Either base substitutions and indels or genome rearrangements result. Here we discovered that most small basic proteins that compact the genome, nucleoid-associated proteins (NAPs), promote or inhibit mutagenic break repair (MBR) via different routes. Of 15 NAPs, H-NS, Fis, CspE, and CbpA were required for MBR; Dps inhibited MBR; StpA and Hha did neither; and five others were characterized previously. Three essential genes were not tested. Using multiple tests, we found the following: First, Dps, which reduces reactive oxygen species (ROS), inhibited MBR, implicating ROS in MBR. Second, CbpA promoted F' plasmid maintenance, allowing MBR to be measured in an F'-based assay. Third, Fis was required for activation of the SOS DNA-damage response and could be substituted in MBR by SOS-induced levels of DinB error-prone DNA polymerase. Thus, Fis promoted MBR by allowing SOS activation. Fourth, H-NS represses ROS detoxifier sodB and was substituted in MBR by deletion of sodB, which was not otherwise mutagenic. We conclude that normal ROS levels promote MBR and that H-NS promotes MBR by maintaining ROS. CspE positively regulates RpoS, which is required for MBR. Four of five previously characterized NAPs promoted stress responses that enhance MBR. Hence, most NAPs affect MBR, the majority via regulatory functions. The data show that a total of six NAPs promote MBR by regulating stress responses, indicating the importance of nucleoid structure and function to the regulation of MBR and of coupling mutagenesis to stress, creating genetic diversity responsively.
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Affiliation(s)
- Jessica M Moore
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, 77030 Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, 77030
| | - David Magnan
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, 77030 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - Ana K Mojica
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, 77030 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030 Undergraduate Program on Genomic Sciences, National Autonomous University of Mexico, Cuernavaca, 62210, Morelos, Mexico
| | - María Angélica Bravo Núñez
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, 77030 Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, 77030 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
| | - David Bates
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, 77030 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030 Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, 77030
| | - Susan M Rosenberg
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, 77030 Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, 77030 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030 Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, 77030
| | - P J Hastings
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, 77030 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030
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13
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Nehring RB, Gu F, Lin HY, Gibson JL, Blythe MJ, Wilson R, Bravo Núñez MA, Hastings PJ, Louis EJ, Frisch RL, Hu JC, Rosenberg SM. An ultra-dense library resource for rapid deconvolution of mutations that cause phenotypes in Escherichia coli. Nucleic Acids Res 2015; 44:e41. [PMID: 26578563 PMCID: PMC4797258 DOI: 10.1093/nar/gkv1131] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 10/15/2015] [Indexed: 01/26/2023] Open
Abstract
With the wide availability of whole-genome sequencing (WGS), genetic mapping has become the rate-limiting step, inhibiting unbiased forward genetics in even the most tractable model organisms. We introduce a rapid deconvolution resource and method for untagged causative mutations after mutagenesis, screens, and WGS in Escherichia coli. We created Deconvoluter—ordered libraries with selectable insertions every 50 kb in the E. coli genome. The Deconvoluter method uses these for replacement of untagged mutations in the genome using a phage-P1-based gene-replacement strategy. We validate the Deconvoluter resource by deconvolution of 17 of 17 phenotype-altering mutations from a screen of N-ethyl-N-nitrosourea-induced mutants. The Deconvoluter resource permits rapid unbiased screens and gene/function identification and will enable exploration of functions of essential genes and undiscovered genes/sites/alleles not represented in existing deletion collections. This resource for unbiased forward-genetic screens with mapping-by-sequencing (‘forward genomics’) demonstrates a strategy that could similarly enable rapid screens in many other microbes.
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Affiliation(s)
- Ralf B Nehring
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA The Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Franklin Gu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hsin-Yu Lin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA The Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Janet L Gibson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA The Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Martin J Blythe
- Deep Seq. Centre for Genetics and Genomics, Queens Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Ray Wilson
- Deep Seq. Centre for Genetics and Genomics, Queens Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - María Angélica Bravo Núñez
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA The Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA Undergraduate Program in Genomic Sciences, National Autonomous University of Mexico, 62210 Cuernavaca, Mexico
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA The Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Edward J Louis
- Deep Seq. Centre for Genetics and Genomics, Queens Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Ryan L Frisch
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA The Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - James C Hu
- Department of Biochemistry and Biophysics, Texas A&M University and Texas Agrilife Research, College Station, TX 77843, USA
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA The Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
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14
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Shee C, Cox BD, Gu F, Luengas EM, Joshi MC, Chiu LY, Magnan D, Halliday JA, Frisch RL, Gibson JL, Nehring RB, Do HG, Hernandez M, Li L, Herman C, Hastings PJ, Bates D, Harris RS, Miller KM, Rosenberg SM. Engineered proteins detect spontaneous DNA breakage in human and bacterial cells. eLife 2013; 2:e01222. [PMID: 24171103 PMCID: PMC3809393 DOI: 10.7554/elife.01222] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 09/16/2013] [Indexed: 01/10/2023] Open
Abstract
Spontaneous DNA breaks instigate genomic changes that fuel cancer and evolution, yet direct quantification of double-strand breaks (DSBs) has been limited. Predominant sources of spontaneous DSBs remain elusive. We report synthetic technology for quantifying DSBs using fluorescent-protein fusions of double-strand DNA end-binding protein, Gam of bacteriophage Mu. In Escherichia coli GamGFP forms foci at chromosomal DSBs and pinpoints their subgenomic locations. Spontaneous DSBs occur mostly one per cell, and correspond with generations, supporting replicative models for spontaneous breakage, and providing the first true breakage rates. In mammalian cells GamGFP-labels laser-induced DSBs antagonized by end-binding protein Ku; co-localizes incompletely with DSB marker 53BP1 suggesting superior DSB-specificity; blocks resection; and demonstrates DNA breakage via APOBEC3A cytosine deaminase. We demonstrate directly that some spontaneous DSBs occur outside of S phase. The data illuminate spontaneous DNA breakage in E. coli and human cells and illustrate the versatility of fluorescent-Gam for interrogation of DSBs in living cells. DOI:http://dx.doi.org/10.7554/eLife.01222.001.
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Affiliation(s)
- Chandan Shee
- Department of Molecular and Human Genetics , Baylor College of Medicine , Houston , United States ; Department of Molecular Virology and Microbiology , Baylor College of Medicine , Houston , United States ; Dan L Duncan Cancer Center, Baylor College of Medicine , Houston , United States ; Department of Biochemistry, Molecular Biology , Baylor College of Medicine , Houston , United States
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15
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Moore JM, Wimberly H, Thornton PC, Rosenberg SM, Hastings PJ. Gross chromosomal rearrangement mediated by DNA replication in stressed cells: evidence from Escherichia coli. Ann N Y Acad Sci 2012; 1267:103-9. [PMID: 22954223 DOI: 10.1111/j.1749-6632.2012.06587.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gross chromosomal rearrangements (GCRs), or changes in chromosome structure, play central roles in evolution and are central to cancer formation and progression. GCRs underlie copy number variation (CNV), and therefore genomic disorders that stem from CNV. We study amplification in Escherichia coli as a model system to understand mechanisms and circumstances of GCR formation. Here, we summarize observations that led us to postulate that GCR occurs by a replicative mechanism as part of activated stress responses. We report that we do not find RecA to be downregulated by stress on a population basis and that constitutive expression of RecA does not inhibit amplification, as would be expected if downregulation of RecA made cells permissive for nonhomologous recombination. Strains deleted for the genes for three proteins that inhibit RecA activity, psiB, dinI, and recX, all show unaltered amplification, suggesting that if they do downregulate RecA indirectly, this activity does not promote amplification.
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Affiliation(s)
- J M Moore
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
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16
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Rosenberg SM, Shee C, Frisch RL, Hastings PJ. Stress-induced mutation via DNA breaks in Escherichia coli: a molecular mechanism with implications for evolution and medicine. Bioessays 2012; 34:885-92. [PMID: 22911060 PMCID: PMC3533179 DOI: 10.1002/bies.201200050] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Evolutionary theory assumed that mutations occur constantly, gradually, and randomly over time. This formulation from the "modern synthesis" of the 1930s was embraced decades before molecular understanding of genes or mutations. Since then, our labs and others have elucidated mutation mechanisms activated by stress responses. Stress-induced mutation mechanisms produce mutations, potentially accelerating evolution, specifically when cells are maladapted to their environment, that is, when they are stressed. The mechanisms of stress-induced mutation that are being revealed experimentally in laboratory settings provide compelling models for mutagenesis that propels pathogen-host adaptation, antibiotic resistance, cancer progression and resistance, and perhaps much of evolution generally. We discuss double-strand-break-dependent stress-induced mutation in Escherichia coli. Recent results illustrate how a stress response activates mutagenesis and demonstrate this mechanism's generality and importance to spontaneous mutation. New data also suggest a possible harmony between previous, apparently opposed, models for the molecular mechanism. They additionally strengthen the case for anti-evolvability therapeutics for infectious disease and cancer.
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Affiliation(s)
- Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
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17
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Cui J, Mao X, Olman V, Hastings PJ, Xu Y. Hypoxia and miscoupling between reduced energy efficiency and signaling to cell proliferation drive cancer to grow increasingly faster. J Mol Cell Biol 2012; 4:174-6. [PMID: 22523396 DOI: 10.1093/jmcb/mjs017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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18
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Liu P, Erez A, Nagamani SCS, Dhar SU, Kołodziejska KE, Dharmadhikari AV, Cooper ML, Wiszniewska J, Zhang F, Withers MA, Bacino CA, Campos-Acevedo LD, Delgado MR, Freedenberg D, Garnica A, Grebe TA, Hernández-Almaguer D, Immken L, Lalani SR, McLean SD, Northrup H, Scaglia F, Strathearn L, Trapane P, Kang SHL, Patel A, Cheung SW, Hastings PJ, Stankiewicz P, Lupski JR, Bi W. Chromosome catastrophes involve replication mechanisms generating complex genomic rearrangements. Cell 2011; 146:889-903. [PMID: 21925314 DOI: 10.1016/j.cell.2011.07.042] [Citation(s) in RCA: 320] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 06/06/2011] [Accepted: 07/25/2011] [Indexed: 10/25/2022]
Abstract
Complex genomic rearrangements (CGRs) consisting of two or more breakpoint junctions have been observed in genomic disorders. Recently, a chromosome catastrophe phenomenon termed chromothripsis, in which numerous genomic rearrangements are apparently acquired in one single catastrophic event, was described in multiple cancers. Here, we show that constitutionally acquired CGRs share similarities with cancer chromothripsis. In the 17 CGR cases investigated, we observed localization and multiple copy number changes including deletions, duplications, and/or triplications, as well as extensive translocations and inversions. Genomic rearrangements involved varied in size and complexities; in one case, array comparative genomic hybridization revealed 18 copy number changes. Breakpoint sequencing identified characteristic features, including small templated insertions at breakpoints and microhomology at breakpoint junctions, which have been attributed to replicative processes. The resemblance between CGR and chromothripsis suggests similar mechanistic underpinnings. Such chromosome catastrophic events appear to reflect basic DNA metabolism operative throughout an organism's life cycle.
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Affiliation(s)
- Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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19
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Hastings PJ, Hersh MN, Thornton PC, Fonville NC, Slack A, Frisch RL, Ray MP, Harris RS, Leal SM, Rosenberg SM. Competition of Escherichia coli DNA polymerases I, II and III with DNA Pol IV in stressed cells. PLoS One 2010; 5:e10862. [PMID: 20523737 PMCID: PMC2877720 DOI: 10.1371/journal.pone.0010862] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 05/06/2010] [Indexed: 01/07/2023] Open
Abstract
Escherichia coli has five DNA polymerases, one of which, the low-fidelity Pol IV or DinB, is required for stress-induced mutagenesis in the well-studied Lac frameshift-reversion assay. Although normally present at ∼200 molecules per cell, Pol IV is recruited to acts of DNA double-strand-break repair, and causes mutagenesis, only when at least two cellular stress responses are activated: the SOS DNA-damage response, which upregulates DinB ∼10-fold, and the RpoS-controlled general-stress response, which upregulates Pol IV about 2-fold. DNA Pol III was also implicated but its role in mutagenesis was unclear. We sought in vivo evidence on the presence and interactions of multiple DNA polymerases during stress-induced mutagenesis. Using multiply mutant strains, we provide evidence of competition of DNA Pols I, II and III with Pol IV, implying that they are all present at sites of stress-induced mutagenesis. Previous data indicate that Pol V is also present. We show that the interactions of Pols I, II and III with Pol IV result neither from, first, induction of the SOS response when particular DNA polymerases are removed, nor second, from proofreading of DNA Pol IV errors by the editing functions of Pol I or Pol III. Third, we provide evidence that Pol III itself does not assist with but rather inhibits Pol IV-dependent mutagenesis. The data support the remaining hypothesis that during the acts of DNA double-strand-break (DSB) repair, shown previously to underlie stress-induced mutagenesis in the Lac system, there is competition of DNA polymerases I, II and III with DNA Pol IV for action at the primer terminus. Up-regulation of Pol IV, and possibly other stress-response-controlled factor(s), tilt the competition in favor of error-prone Pol IV at the expense of more accurate polymerases, thus producing stress-induced mutations. This mutagenesis assay reveals the DNA polymerases operating in DSB repair during stress and also provides a sensitive indicator for DNA polymerase competition and choice in vivo.
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Affiliation(s)
- P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America.
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20
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Gibson JL, Lombardo MJ, Thornton PC, Hu KH, Galhardo RS, Beadle B, Habib A, Magner DB, Frost LS, Herman C, Hastings PJ, Rosenberg SM. The sigma(E) stress response is required for stress-induced mutation and amplification in Escherichia coli. Mol Microbiol 2010; 77:415-30. [PMID: 20497332 PMCID: PMC2909356 DOI: 10.1111/j.1365-2958.2010.07213.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pathways of mutagenesis are induced in microbes under adverse conditions controlled by stress responses. Control of mutagenesis by stress responses may accelerate evolution specifically when cells are maladapted to their environments, i.e. are stressed. Stress-induced mutagenesis in the Escherichia coli Lac assay occurs either by ‘point’ mutation or gene amplification. Point mutagenesis is associated with DNA double-strand-break (DSB) repair and requires DinB error-prone DNA polymerase and the SOS DNA-damage- and RpoS general-stress responses. We report that the RpoE envelope-protein-stress response is also required. In a screen for mutagenesis-defective mutants, we isolated a transposon insertion in the rpoE P2 promoter. The insertion prevents rpoE induction during stress, but leaves constitutive expression intact, and allows cell viability. rpoE insertion and suppressed null mutants display reduced point mutagenesis and maintenance of amplified DNA. Furthermore, σE acts independently of stress responses previously implicated: SOS/DinB and RpoS, and of σ32, which was postulated to affect mutagenesis. I-SceI-induced DSBs alleviated much of the rpoE phenotype, implying that σE promoted DSB formation. Thus, a third stress response and stress input regulate DSB-repair-associated stress-induced mutagenesis. This provides the first report of mutagenesis promoted by σE, and implies that extracytoplasmic stressors may affect genome integrity and, potentially, the ability to evolve.
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Affiliation(s)
- Janet L Gibson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA
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21
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Hastings PJ, Lupski JR, Rosenberg SM, Ira G. Mechanisms of change in gene copy number. Nat Rev Genet 2009. [PMID: 19597530 DOI: 10.1038/nrg2593.mechanisms] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Deletions and duplications of chromosomal segments (copy number variants, CNVs) are a major source of variation between individual humans and are an underlying factor in human evolution and in many diseases, including mental illness, developmental disorders and cancer. CNVs form at a faster rate than other types of mutation, and seem to do so by similar mechanisms in bacteria, yeast and humans. Here we review current models of the mechanisms that cause copy number variation. Non-homologous end-joining mechanisms are well known, but recent models focus on perturbation of DNA replication and replication of non-contiguous DNA segments. For example, cellular stress might induce repair of broken replication forks to switch from high-fidelity homologous recombination to non-homologous repair, thus promoting copy number change.
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Affiliation(s)
- P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.
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22
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Abstract
Deletions and duplications of chromosomal segments (copy number variants, CNVs) are a major source of variation between individual humans and are an underlying factor in human evolution and in many diseases, including mental illness, developmental disorders and cancer. CNVs form at a faster rate than other types of mutation, and seem to do so by similar mechanisms in bacteria, yeast and humans. Here we review current models of the mechanisms that cause copy number variation. Non-homologous end-joining mechanisms are well known, but recent models focus on perturbation of DNA replication and replication of non-contiguous DNA segments. For example, cellular stress might induce repair of broken replication forks to switch from high-fidelity homologous recombination to non-homologous repair, thus promoting copy number change.
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Affiliation(s)
- P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.
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23
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Wu X, Strome ED, Meng Q, Hastings PJ, Plon SE, Kimmel M. A robust estimator of mutation rates. Mutat Res 2009; 661:101-109. [PMID: 19100753 DOI: 10.1016/j.mrfmmm.2008.11.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 11/13/2008] [Accepted: 11/21/2008] [Indexed: 05/27/2023]
Abstract
Fluctuation analysis is an established and widely used technique of estimating mutation rates in cultured cells. This paper presents a modified median estimator of mutation rates, which is novel because it allows for unequal population sizes N(t) of the parallel cultures, and helps to detect and reduce the estimation variability. Simulation results show a good accuracy and robustness of the modified median estimator compared with the median estimator and the maximum likelihood estimator. The proposed estimator, based on the Luria-Delbrück model, is applied to 20 yeast datasets collected during 3 different days for a study of chromosome loss and recombination in wild-type Saccharomyces cerevisiae strains. The estimates obtained display among-experiment variability, which is inflated with respect to the model predictions on simulated data. Further investigation in S. cerevisiae and Escherichia coli uncovers an empirical inverse relationship between the population sizes N(t) and the mutation rate estimates under certain experimental conditions. The impact of these effects on the practice of fluctuation analysis is discussed.
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Affiliation(s)
- Xiaowei Wu
- Department of Statistics, Rice University, Houston, TX 77005, USA.
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24
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Abstract
Modern techniques are revealing that repetition of segments of the genome, called amplification or gene amplification, is very common. Amplification is found in all domains of life, and occurs under conditions where enhanced expression of the amplified genes is advantageous. Amplification extends the range of gene expression beyond that which is achieved by control systems. It also is reversible because it is unstable, breaking down by homologous recombination. Amplification is believed to be the driving force in the clustering of related functions, in that it allows them to be amplified together. Amplification provides the extra copies of genes that allow evolution of functions to occur while retaining the original function. Amplification can be induced in response to cellular stressors. In many cases, it has been shown that the genomic regions that are amplified include those genes that are appropriate to upregulate for a specific stressor. There is some evidence that amplification occurs as part of a broad, general stress response, suggesting that organisms have the capacity to induce structural changes in the genome. This then allows adaptation to the stressful conditions. The mechanisms by which amplification arises are now being studied at the molecular level, but much is still unknown about the mechanisms in all organisms. Recent advances in our understanding of amplification in bacteria suggests new interpretations of events leading to human copy number variation, as well as evolution in general.
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Affiliation(s)
- P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.
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25
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Abstract
Our concept of a stable genome is evolving to one in which genomes are plastic and responsive to environmental changes. Growing evidence shows that a variety of environmental stresses induce genomic instability in bacteria, yeast, and human cancer cells, generating occasional fitter mutants and potentially accelerating adaptive evolution. The emerging molecular mechanisms of stress-induced mutagenesis vary but share telling common components that underscore two common themes. The first is the regulation of mutagenesis in time by cellular stress responses, which promote random mutations specifically when cells are poorly adapted to their environments, i.e., when they are stressed. A second theme is the possible restriction of random mutagenesis in genomic space, achieved via coupling of mutation-generating machinery to local events such as DNA-break repair or transcription. Such localization may minimize accumulation of deleterious mutations in the genomes of rare fitter mutants, and promote local concerted evolution. Although mutagenesis induced by stresses other than direct damage to DNA was previously controversial, evidence for the existence of various stress-induced mutagenesis programs is now overwhelming and widespread. Such mechanisms probably fuel evolution of microbial pathogenesis and antibiotic-resistance, and tumor progression and chemotherapy resistance, all of which occur under stress, driven by mutations. The emerging commonalities in stress-induced-mutation mechanisms provide hope for new therapeutic interventions for all of these processes.
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Affiliation(s)
- Rodrigo S Galhardo
- Department of Molecular and Human Genetics, Baylor College, Houston, Texas 77030-3411, USA
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26
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Mukhopadhyay SS, Leung KS, Hicks MJ, Hastings PJ, Youssoufian H, Plon SE. Defective mitochondrial peroxiredoxin-3 results in sensitivity to oxidative stress in Fanconi anemia. ACTA ACUST UNITED AC 2006; 175:225-35. [PMID: 17060495 PMCID: PMC2064564 DOI: 10.1083/jcb.200607061] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cells from patients with Fanconi anemia (FA), an inherited disorder that includes bone marrow failure and cancer predisposition, have increased sensitivity to oxidative stress through an unknown mechanism. We demonstrate that the FA group G (FANCG) protein is found in mitochondria. Wild-type but not G546R mutant FANCG physically interacts with the mitochondrial peroxidase peroxiredoxin-3 (PRDX3). PRDX3 is deregulated in FA cells, including cleavage by a calpainlike cysteine protease and mislocalization. FA-G cells demonstrate distorted mitochondrial structures, and mitochondrial extracts have a sevenfold decrease in thioredoxin-dependent peroxidase activity. Transient overexpression of PRDX3 suppresses the sensitivity of FA-G cells to H2O2, and decreased PRDX3 expression increases sensitivity to mitomycin C. Cells from the FA-A and -C subtypes also have PRDX3 cleavage and decreased peroxidase activity. This study demonstrates a role for the FA proteins in mitochondria witsh sensitivity to oxidative stress resulting from diminished peroxidase activity. These defects may lead to apoptosis and the accumulation of oxidative DNA damage in bone marrow precursors.
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27
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Lopez CR, Yang S, Deibler RW, Ray SA, Pennington JM, Digate RJ, Hastings PJ, Rosenberg SM, Zechiedrich EL. A role for topoisomerase III in a recombination pathway alternative to RuvABC. Mol Microbiol 2006; 58:80-101. [PMID: 16164551 DOI: 10.1111/j.1365-2958.2005.04812.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The physiological role of topoisomerase III is unclear for any organism. We show here that the removal of topoisomerase III in temperature sensitive topoisomerase IV mutants in Escherichia coli results in inviability at the permissive temperature. The removal of topoisomerase III has no effect on the accumulation of catenated intermediates of DNA replication, even when topoisomerase IV activity is removed. Either recQ or recA null mutations, but not helD null or lexA3, partially rescued the synthetic lethality of the double topoisomerase III/IV mutant, indicating a role for topoisomerase III in recombination. We find a bias against deleting the gene encoding topoisomerase III in ruvC53 or DeltaruvABC backgrounds compared with the isogenic wild-type strains. The topoisomerase III RuvC double mutants that can be constructed are five- to 10-fold more sensitive to UV irradiation and mitomycin C treatment and are twofold less efficient in transduction efficiency than ruvC53 mutants. The overexpression of ruvABC allows the construction of the topoisomerase III/IV double mutant. These data are consistent with a role for topoisomerase III in disentangling recombination intermediates as an alternative to RuvABC to maintain the stability of the genome.
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Affiliation(s)
- Christopher R Lopez
- Interdepartmental Program in Cell and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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28
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Hastings PJ, Slack A, Petrosino JF, Rosenberg SM. Adaptive amplification and point mutation are independent mechanisms: evidence for various stress-inducible mutation mechanisms. PLoS Biol 2004; 2:e399. [PMID: 15550983 PMCID: PMC529313 DOI: 10.1371/journal.pbio.0020399] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2003] [Accepted: 09/20/2004] [Indexed: 11/22/2022] Open
Abstract
“Adaptive mutation” denotes a collection of processes in which cells respond to growth-limiting environments by producing compensatory mutants that grow well, apparently violating fundamental principles of evolution. In a well-studied model, starvation of stationary-phase lac− Escherichia coli cells on lactose medium induces Lac+ revertants at higher frequencies than predicted by usual mutation models. These revertants carry either a compensatory frameshift mutation or a greater than 20-fold amplification of the leaky lac allele. A crucial distinction between alternative hypotheses for the mechanisms of adaptive mutation hinges on whether these amplification and frameshift mutation events are distinct, or whether amplification is a molecular intermediate, producing an intermediate cell type, in colonies on a pathway to frameshift mutation. The latter model allows the evolutionarily conservative idea of increased mutations (per cell) without increased mutation rate (by virtue of extra gene copies per cell), whereas the former requires an increase in mutation rate, potentially accelerating evolution. To resolve these models, we probed early events leading to rare adaptive mutations and report several results that show that amplification is not the precursor to frameshift mutation but rather is an independent adaptive outcome. (i) Using new high-resolution selection methods and stringent analysis of all cells in very young (micro)colonies (500–10,000 cells), we find that most mutant colonies contain no detectable lac-amplified cells, in contrast with previous reports. (ii) Analysis of nascent colonies, as young as the two-cell stage, revealed mutant Lac+ cells with no lac-amplified cells present. (iii) Stringent colony-fate experiments show that microcolonies of lac-amplified cells grow to form visible colonies of lac-amplified, not mutant, cells. (iv) Mutant cells do not overgrow lac-amplified cells in microcolonies fast enough to mask the lac-amplified cells. (v) lac-amplified cells are not SOS-induced, as was proposed to explain elevated mutation in a sequential model. (vi) Amplification, and not frameshift mutation, requires DNA polymerase I, demonstrating that mutation is separable from amplification, and also illuminating the amplification mechanism. We conclude that amplification and mutation are independent outcomes of adaptive genetic change. We suggest that the availability of alternative pathways for genetic/evolutionary adaptation and clonal expansion under stress may be exploited during processes ranging from the evolution of drug resistance to cancer progression. Cells can respond to stress by apparently increasing their mutation rate. This study provides evidence that there is more than one pathway by which cells achieve such a response
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Affiliation(s)
- P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
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29
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Abstract
As do many temperate bacteriophages, integrating conjugative elements (ICEs) recruit the SOS DNA damage response to mobilize themselves from the bacterial chromosome and infect other cells. This transfers resistance to multiple antibiotics. Several commonly used antibiotics induce the SOS response, potentially hastening genetic change and the evolution to resistance of pathogenic populations. The use of such antibiotics should be reconsidered.
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Affiliation(s)
- P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030-3411, USA.
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30
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Rosenberg SM, Hastings PJ. Adaptive point mutation and adaptive amplification pathways in the Escherichia coli Lac system: stress responses producing genetic change. J Bacteriol 2004; 186:4838-43. [PMID: 15262914 PMCID: PMC451650 DOI: 10.1128/jb.186.15.4838-4843.2004] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, BCM-S809A Mail Stop BCM225, Houston, TX 77030-3411, USA.
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31
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Affiliation(s)
- Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, BCM-S809A, Mail Stop BCM225, Houston, TX 77030-3411, USA.
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Affiliation(s)
- Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030-3411, USA.
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Hersh MN, Ponder RG, Hastings PJ, Rosenberg SM. Adaptive mutation and amplification in Escherichia coli: two pathways of genome adaptation under stress. Res Microbiol 2004; 155:352-9. [PMID: 15207867 DOI: 10.1016/j.resmic.2004.01.020] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2003] [Accepted: 01/20/2004] [Indexed: 10/26/2022]
Abstract
The neo-Darwinists suggested that evolution is constant and gradual, and thus that genetic changes that drive evolution should be too. However, more recent understanding of phenomena called adaptive mutation in microbes indicates that mutation rates can be elevated in response to stress, producing beneficial and other mutations. We review evidence that, in Escherichia coli, two separate mechanisms of stress-induced genetic change occur that revert a lac frameshift allele allowing growth on lactose medium. First, compensatory frameshift ("point") mutations occur by a mechanism that includes DNA double-strand breaks and (we have suggested) their error-prone repair. Point mutation requires induction of the RpoS-dependent general stress response, and the SOS DNA damage response leading to upregulation of the error-prone DNA polymerase DinB (Pol IV), and occurs during a transient limitation of post-replicative mismatch repair activity. A second mechanism, adaptive amplification, entails amplification of the leaky lac allele to 20-50 tandem repeats. These provide sufficient beta-galactosidase activity for growth, thereby apparently deflecting cells from the point mutation pathway. Unlike point mutation, amplification neither occurs in hypermutating cells nor requires SOS or DinB, but like point mutation, amplification requires the RpoS-dependent stress response. Similar processes are being found in other bacterial systems and yeast. Stress-induced genetic changes may underlie much of microbial evolution, pathogenesis and antibiotic resistance, and also cancer formation, progression and drug resistance.
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Affiliation(s)
- Megan N Hersh
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Rm S809, Mail Stop 225, Houston, TX 77030-3411, USA
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Affiliation(s)
- Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
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Abstract
"Adaptive" or "stationary-phase" mutation is a collection of apparent stress responses in which cells exposed to a growth-limiting environment generate genetic changes, some of which can allow resumption of rapid growth. In the well-characterized Lac system of Escherichia coli, reversions of a lac frameshift allele give rise to adaptive point mutations. Also in this system, adaptive gene amplification has been documented as a separate and parallel response that allows growth on lactose medium without acquisition of a compensatory frameshift mutation. In amplification, the DNA region containing the weakly functional lac allele becomes amplified to multiple copies, which produce sufficient enzyme activity to allow growth on the otherwise growth-limiting lactose medium. The amplifications are "adaptive" in that they occur after cells encounter the growth-limiting environment. Adaptive amplification is a reversible genetic change that allows adaptation and growth. It may be similar to chromosomal instability observed in the origins and progression of many cancers. We explore possible molecular mechanisms of adaptive amplification in the bacterial system and note parallels to chromosomal instability in other systems.
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Affiliation(s)
- P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room T809 Mail Stop 225, Houston, TX 77030-3411, USA.
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Abstract
Adaptive point mutation and amplification are induced responses to environmental stress, promoting genetic changes that can enhance survival. A specialized adaptive mutation mechanism has been documented in one Escherichia coli assay, but its enzymatic basis remained unclear. We report that the SOS-inducible, error-prone DNA polymerase (pol) IV, encoded by dinB, is required for adaptive point mutation in the E. coli lac operon. A nonpolar dinB mutation reduces adaptive mutation frequencies by 85% but does not affect adaptive amplification, growth-dependent mutation, or survival after oxidative or UV damage. We show that pol IV, together with the major replicase, pol III, can account for all adaptive point mutations at lac. The results identify a role for pol IV in inducible genetic change.
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Affiliation(s)
- G J McKenzie
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030-3411, USA
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Abstract
Adaptive mutation is an induced response to environmental stress in which mutation rates rise, producing permanent genetic changes that can adapt cells to stress. This contrasts with neo-Darwinian views of genetic change rates blind to environmental conditions. DNA amplification is a flexible, reversible genomic change that has long been postulated to be adaptive. We report the discovery of adaptive amplification at the lac operon in Escherichia coli. Additionally, we find that adaptive amplification is separate from, and does not lead to, adaptive point mutation. This contradicts a prevailing alternative hypothesis whereby adaptive mutation is normal mutability in amplified DNA. Instead, adaptive mutation and amplification are parallel routes of inducible genetic instability allowing rapid evolution under stress, and escape from growth inhibition.
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Affiliation(s)
- P J Hastings
- Department of Molecular and Human Genetics Baylor College of Medicine One Baylor Plaza Houston, TX 77030, USA.
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Bull HJ, McKenzie GJ, Hastings PJ, Rosenberg SM. Response to John Cairns: The Contribution of Transiently Hypermutable Cells to Mutation in Stationary Phase. Genetics 2000. [DOI: 10.1093/genetics/156.2.925] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Gregory J McKenzie
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030-3498
| | - P J Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030-3498
| | - Susan M Rosenberg
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030-3498
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Bull HJ, McKenzie GJ, Hastings PJ, Rosenberg SM. Evidence that stationary-phase hypermutation in the Escherichia coli chromosome is promoted by recombination. Genetics 2000; 154:1427-37. [PMID: 10747042 PMCID: PMC1461015 DOI: 10.1093/genetics/154.4.1427] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Adaptive (or stationary-phase) mutation is a group of phenomena in which mutations appear to occur more often when selected than when not. They may represent cellular responses to the environment in which the genome is altered to allow survival. The best-characterized assay system and mechanism is reversion of a lac allele on an F' sex plasmid in Escherichia coli, in which the stationary-phase mutability requires homologous recombination functions. A key issue has concerned whether the recombination-dependent mutation mechanism is F' specific or is general. Hypermutation of chromosomal genes occurs in association with adaptive Lac(+) mutation. Here we present evidence that the chromosomal hypermutation is promoted by recombination. Hyperrecombinagenic recD cells show elevated chromosomal hypermutation. Further, recG mutation, which promotes accumulation of recombination intermediates proposed to prime replication and mutation, also stimulates chromosomal hypermutation. The coincident mutations at lac (on the F') and chromosomal genes behave as independent events, whereas coincident mutations at lac and other F-linked sites do not. This implies that transient covalent linkage of F' and chromosomal DNA (Hfr formation) does not underlie chromosomal mutation. The data suggest that recombinational stationary-phase mutation occurs in the bacterial chromosome and thus can be a general strategy for programmed genetic change.
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Affiliation(s)
- H J Bull
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030-3498, USA
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Harris RS, Feng G, Ross KJ, Sidhu R, Thulin C, Longerich S, Szigety SK, Hastings PJ, Winkler ME, Rosenberg SM. Mismatch repair is diminished during stationary-phase mutation. Mutat Res 1999; 437:51-60. [PMID: 10425389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
This paper is an invited Response to a recent Commentary [P.L. Foster, Rev. Mut. Res. 436 (1999) 179-184] entitled "Are adaptive mutations due to a decline in mismatch repair? The evidence is lacking". The Commentary argues that no evidence exists supporting the idea that mismatch repair is limiting specifically during stationary-phase mutation. A primary concern of the author is to question the method that we used previously to measure growth-dependent mutation. In this method, mutation rates are calculated using counts of mutant colonies taken at times when those colonies arise, rather than at a predetermined, fixed time. Here we show further data that illustrate why this must be done to ensure accurate mutation measurements. Such accuracy was necessary for our published determination that mismatch repair proteins are not limiting during growth-dependent mutation, but become so during stationary-phase mutation. We review the evidence supporting the idea that stationary-phase reversion of a lac frameshift mutation occurs in an environment of decreased mismatch repair capacity. Those data are substantial. The data presented in the Commentary, in apparent contradiction to this idea, do not justify the conclusion presented there.
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Affiliation(s)
- R S Harris
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
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Reiter LT, Hastings PJ, Nelis E, De Jonghe P, Van Broeckhoven C, Lupski JR. Human meiotic recombination products revealed by sequencing a hotspot for homologous strand exchange in multiple HNPP deletion patients. Am J Hum Genet 1998; 62:1023-33. [PMID: 9545397 PMCID: PMC1377084 DOI: 10.1086/301827] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The HNPP (hereditary neuropathy with liability to pressure palsies) deletion and CMT1A (Charcot-Marie-Tooth disease type 1A) duplication are the reciprocal products of homologous recombination events between misaligned flanking CMT1A-REP repeats on chromosome 17p11. 2-p12. A 1.7-kb hotspot for homologous recombination was previously identified wherein the relative risk of an exchange event is 50 times higher than in the surrounding 98.7% identical sequence shared by the CMT1A-REPs. To refine the region of exchange further, we designed a PCR strategy to amplify the recombinant CMT1A-REP from HNPP patients as well as the proximal and distal CMT1A-REPs from control individuals. By comparing the sequences across recombinant CMT1A-REPs to that of the proximal and distal CMT1A-REPs, the exchange was mapped to a 557-bp region within the previously identified 1.7-kb hotspot in 21 of 23 unrelated HNPP deletion patients. Two patients had recombined sequences suggesting an exchange event closer to the mariner-like element previously identified near the hotspot. Five individuals also had interspersed patches of proximal or distal repeat specific DNA sequence indicating potential gene conversion during the exchange of genetic material. Our studies provide a direct observation of human meiotic recombination products. These results are consistent with the hypothesis that minimum efficient processing segments, which have been characterized in Escherichia coli, yeast, and cultured mammalian cells, may be required for efficient homologous meiotic recombination in humans.
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Affiliation(s)
- L T Reiter
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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von Borstel RC, Savage EA, Wang Q, Hennig UG, Ritzel RG, Lee GS, Hamilton MD, Chrenek MA, Tomaszewski RW, Higgins JA, Tenove CJ, Liviero L, Hastings PJ, Korch CT, Steinberg CM. Topical reversion at the HIS1 locus of Saccharomyces cerevisiae. A tale of three mutants. Genetics 1998; 148:1647-54. [PMID: 9560384 PMCID: PMC1460089 DOI: 10.1093/genetics/148.4.1647] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Mutants of the HIS1 locus of the yeast Saccharomyces cerevisiae are suitable reporters for spontaneous reversion events because most reversions are topical, that is, within the locus itself. Thirteen mutations of his1-1 now have been identified with respect to base sequence. Revertants of three mutants and their spontaneous reversion rates are presented: (1) a chain termination mutation (his1-208, née his1-1) that does not revert by mutations of tRNA loci and reverts only by intracodonic suppression; (2) a missense mutation (his1-798, née his1-7) that can revert by intragenic suppression by base substitutions of any sort, including a back mutation as well as one three-base deletion; and (3) a -1 frameshift mutation (his1-434, née his1-19) that only reverts topically by +1 back mutation, +1 intragenic suppression, or a -2 deletion. Often the +1 insertion is accompanied by base substitution events at one or both ends of a run of A's. Missense suppressors of his1-798 are either feeders or nonfeeders, and at four different locations within the locus, a single base substitution encoding an amino acid alteration will suffice to turn the nonfeeder phenotype into a feeder phenotype. Late-appearing revertants of his1-798 were found to be slowly growing leaky mutants rather than a manifestation of adaptive mutagenesis. Spontaneous revertants of his1-208 and his1-434 produced no late-arising colonies.
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Affiliation(s)
- R C von Borstel
- Department of Biological Sciences, University of Alberta, Edmonton, Canada.
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Abstract
In yeast meiotic recombination, alleles used as genetic markers fall into two classes as regards their fate when incorporated into heteroduplex DNA. Normal alleles are those that form heteroduplexes that are nearly always recognized and corrected by the mismatch repair system operating in meiosis. High PMS (postmeiotic segregation) alleles form heteroduplexes that are inefficiently mismatch repaired. We report that placing any of several high PMS alleles very close to normal alleles causes hyperrecombination between these markers. We propose that this hyperrecombination is caused by the high PMS allele blocking a mismatch repair tract initiated from the normal allele, thus preventing corepair of the two alleles, which would prevent formation of recombinants. The results of three point crosses involving two PMS alleles and a normal allele suggest that high PMS alleles placed between two alleles that are normally corepaired block that corepair.
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Affiliation(s)
- P Manivasakam
- Department of Genetics, University of Alberta, Edmonton, Canada.
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Abstract
Integration of linearized plasmids into yeast chromosomes has been used as a model system for the study of recombination initiated by double-strand breaks. The linearized plasmid DNA recombines efficiently into sequences homologous to the ends of the DNA. This efficient recombination occurs both for the configuration in which the break is in a contiguous region of homology (herein called the ends-in configuration) and for "omega" insertions in which plasmid sequences interrupt a linear region of homology (herein called the ends-out configuration). The requirements for integration of these two configurations are expected to be different. We compared these two processes in a yeast strain containing an ends-in target and an ends-out target for the same cut plasmid. Recovery of ends-in events exceeds ends-out events by two- to threefold. Possible causes for the origin of this small bias are discussed. The lack of an extreme difference in frequency implies that cooperativity between the two ends does not contribute to the efficiency with which cut circular plasmids are integrated. This may also be true for the repair of chromosomal double-strand breaks.
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Affiliation(s)
- P J Hastings
- Department of Genetics, University of Alberta, Edmonton, Canada
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Abstract
In fungi, most mitotic recombination and at least some meiotic recombination appear to stem from a process of double-strand break repair. During this repair, recombination occurs by conversion caused by the process of double-strand gap filling, by conversion related to heteroduplex formation where homologous molecules interact by complementary base pairing, and by crossing-over which is probably an occasional byproduct of the repair process. From a review of the genetic and biochemical data and the published models of the process of recombination, the following view emerges: broken ends may be acted upon by nucleases and helicases to produce a recombinagenic end which may have both 3' and 5' single-stranded tails. These postulated split-ends may then act independently to find regions of homology with which to react. Invasion by both ends forms two splice-junctions which prime DNA synthesis towards each other to replace lost information, using the homologous sequences as templates. This process would lead to a structure which consists of a double Holliday junction which may be resolved endonucleolytically, sometimes giving a crossover, or by another means such as the action of topoisomerase, to dissolve the structure without a crossover having been formed.
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Affiliation(s)
- P J Hastings
- Department of Genetics, University of Alberta, Edmonton, Canada
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Abstract
We have constructed a dihydrofolate reductase mutant (dfr1) of Saccharomyces cerevisiae. The mutant has auxotrophic growth requirements for the C1 metabolites dTMP, adenine, histidine and methionine, similar to those of wild-type (wt) strains grown in the presence of methotrexate (MTX). However, unlike wt strains treated with MTX, the growth requirements of the dfr1 mutant are not satisfied by exogenous 5-formyltetrahydrofolic acid (FA; folinic acid) in complex (YEPD) medium. This result is surprising, as yeast cells treated with MTX are expected to be phenocopies of dfr1 mutants. The inability of the mutants to metabolize FA suggests that the DFR1 gene product may have a role in folate metabolism in addition to its well-characterized function in the reduction of dihydrofolate. From dfr1 strains, we have isolated secondary mutants whose growth can be supported by FA in YEPD medium. This FA-utilizing phenotype is attributable to recessive mutations which we have designated fou. In addition to their inability to metabolize FA, the dfr1 strains are unable to grow on medium containing the non-fermentable carbon source glycerol, suggesting that the DFR1 gene product is also required for mitochondrial function. In order to overcome this lack of respiratory activity in the dfr1 mutants, we isolated strains containing a dominant mutation, DIR, which allows growth on glycerol in the presence of antifolate drugs. When crossed into dfr1 strains, the DIR mutation conferred respiratory competence. These strains should be useful in a variety of studies on the genetics and biochemistry of folate metabolism in this simple eukaryote.
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Affiliation(s)
- T Huang
- Department of Genetics, University of Alberta, Edmonton, Canada
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Ray H, Hastings PJ. Variation within flax (Linum usitatissimum) and barley (Hordeum vulgare) in response to allelopathic chemicals. Theor Appl Genet 1992; 84:460-465. [PMID: 24203208 DOI: 10.1007/bf00229507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/1991] [Accepted: 12/19/1991] [Indexed: 06/02/2023]
Abstract
A possible method of manipulating allelopathy would be to develop crop varieties showing an increased tolerance to allelopathic chemicals. We therefore examined four flax (Linum usitatissimum) varieties and two wild Linum species in the presence of p-coumaric acid and four barley (Hordeum vulgare) varieties in the presence of p-coumaric acid, scopoletin and wild oat (Avena fatua) extract. Analysis of variance indicates significant interaction between variety and treatment for shoot and root growth for seedling flax, shoot growth for older flax, and root growth for seedling barley. These differences in tolerance between varieties could be exploited to develop-varieties with greater tolerances to the allelochemicals produced by weeds or in crop residues and therefore potentially more tolerant of the presence of weeds.
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Affiliation(s)
- H Ray
- Department of Genetics, G 216 Biological Sciences Building, University of Alberta, T6G 2E9, Edmonton, Alberta, Canada
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Abstract
In recent years two different styles of model for homologous recombination have been discussed, depending on whether or not the recombination event occurs in the vicinity of a double-strand break in DNA. The models of Holliday and Meselson and Radding exemplify those that do not involve a break whereas the model of Szostak et al is taken as an example of those that do. Recent advances in understanding a prototypic recombination system thought to promote exchange distant from DNA ends, at Chi sites, suggest a mechanism of initiation neither like Holliday/Meselson-Radding nor like Szostak et al. In those models, only one strand of DNA may invade a homologous DNA molecule. We propose a model for Chi in which exonuclease degrades DNA from a double-strand break to the Chi site; the exonuclease is converted into a helicase upon interaction with Chi; unwinding produces a recombinagenic split-end, and both 3'- and 5'-ending strands at the split-end are capable of invading a homologue. Different genetic consequences are proposed to result from invasion by each. We review evidence supporting the split-end model and suggest its application in at least some cases previously considered to proceed via the Meselson/Radding model and by the double-strand-break repair model of Szostak et al.
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Affiliation(s)
- S M Rosenberg
- Department of Genetics, University of Alberta, Edmonton, Canada
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Schiestl RH, Gietz RD, Hastings PJ, Wintersberger U. Interchromosomal and intrachromosomal recombination in rad 18 mutants of Saccharomyces cerevisiae. Mol Gen Genet 1990; 222:25-32. [PMID: 2233677 DOI: 10.1007/bf00283018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The frequency of intra- and interchromosomal recombination was determined in RAD18 and rad18 deletion and rad18-3 mutant strains. It was found that spontaneous interchromosomal recombination at trp5, his1, ade2, and MAT was elevated 10- to 70-fold in the rad18-3 and rad18 delta mutants as compared to the RAD+ strains. On the other hand the frequencies of spontaneous intrachromosomal recombination for the his3 delta 3', his3 delta 5' and the his4C-, his4A- duplications and for heterothallic mating type switching were only marginally elevated in the rad18 deletion mutant, and recombination between ribosomal DNA repeats was only 2-fold elevated in the rad18-3 mutant. These differences may be due to a haploid versus diploid specific difference. However interchromosomal recombination was elevated 40-fold and intrachromosomal recombination was only marginally (1.5-fold) elevated in a diploid homozygous for rad18 delta, arguing against a haploid versus diploid specific difference. Possible explanations for the difference in the elevated levels of intra- versus interchromosomal spontaneous recombination are discussed.
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Affiliation(s)
- R H Schiestl
- Department of Tumor Biology-Cancer Research, University of Vienna, Wien, Austria
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