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Nageshan RK, Krogan N, Cooper JP. Parallel genetic screens identify nuclear envelope homeostasis as a key determinant of telomere entanglement resolution in fission yeast. G3 (BETHESDA, MD.) 2024; 14:jkae078. [PMID: 38657142 PMCID: PMC11228871 DOI: 10.1093/g3journal/jkae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/18/2024] [Accepted: 03/21/2024] [Indexed: 04/26/2024]
Abstract
In fission yeast lacking the telomere binding protein, Taz1, replication forks stall at telomeres, triggering deleterious downstream events. Strand invasion from one taz1Δ telomeric stalled fork to another on a separate (nonsister) chromosome leads to telomere entanglements, which are resolved in mitosis at 32°C; however, entanglement resolution fails at ≤20°C, leading to cold-specific lethality. Previously, we found that loss of the mitotic function of Rif1, a conserved DNA replication and repair factor, suppresses cold sensitivity by promoting resolution of entanglements without affecting entanglement formation. To understand the underlying pathways of mitotic entanglement resolution, we performed a series of genome-wide synthetic genetic array screens to generate a comprehensive list of genetic interactors of taz1Δ and rif1Δ. We modified a previously described screening method to ensure that the queried cells were kept in log phase growth. In addition to recapitulating previously identified genetic interactions, we find that loss of genes encoding components of the nuclear pore complex (NPC) promotes telomere disentanglement and suppresses taz1Δ cold sensitivity. We attribute this to more rapid anaphase midregion nuclear envelope (NE) breakdown in the absence of these NPC components. Loss of genes involved in lipid metabolism reverses the ability of rif1+ deletion to suppress taz1Δ cold sensitivity, again pinpointing NE modulation. A rif1+ separation-of-function mutant that specifically loses Rif1's mitotic functions yields similar genetic interactions. Genes promoting membrane fluidity were enriched in a parallel taz1+ synthetic lethal screen at permissive temperature, cementing the idea that the cold specificity of taz1Δ lethality stems from altered NE homeostasis.
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Affiliation(s)
- Rishi Kumar Nageshan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, 12801 E. 17th Ave, Aurora, CO 80045, USA
- Former address: Telomere Biology Laboratory, Laboratory of Biochemistry and Molecular Biology, NCI, NIH, Bethesda, MD 20892, USA
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, 1700 4th Street, 308D, San Francisco, CA 94158, USA
- Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA 94158, USA
- J. David Gladstone Institutes, San Francisco, CA 94158, USA
| | - Julia Promisel Cooper
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, 12801 E. 17th Ave, Aurora, CO 80045, USA
- Former address: Telomere Biology Laboratory, Laboratory of Biochemistry and Molecular Biology, NCI, NIH, Bethesda, MD 20892, USA
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2
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Borao S, Vega M, Boronat S, Hidalgo E, Hümmer S, Ayté J. A systematic screen identifies Saf5 as a link between splicing and transcription in fission yeast. PLoS Genet 2024; 20:e1011316. [PMID: 38833506 PMCID: PMC11178228 DOI: 10.1371/journal.pgen.1011316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 06/14/2024] [Accepted: 05/23/2024] [Indexed: 06/06/2024] Open
Abstract
Splicing is an important step of gene expression regulation in eukaryotes, as there are many mRNA precursors that can be alternatively spliced in different tissues, at different cell cycle phases or under different external stimuli. We have developed several integrated fluorescence-based in vivo splicing reporter constructs that allow the quantification of fission yeast splicing in vivo on intact cells, and we have compared their splicing efficiency in a wild type strain and in a prp2-1 (U2AF65) genetic background, showing a clear dependency between Prp2 and a consensus signal at 5' splicing site (5'SS). To isolate novel genes involved in regulated splicing, we have crossed the reporter showing more intron retention with the Schizosaccharomyces pombe knock out collection. Among the candidate genes involved in the regulation of splicing, we have detected strong splicing defects in two of the mutants -Δcwf12, a member of the NineTeen Complex (NTC) and Δsaf5, a methylosome subunit that acts together with the survival motor neuron (SMN) complex in small nuclear ribonucleoproteins (snRNP) biogenesis. We have identified that strains with mutations in cwf12 have inefficient splicing, mainly when the 5'SS differs from the consensus. However, although Δsaf5 cells also have some dependency on 5'SS sequence, we noticed that when one intron of a given pre-mRNA was affected, the rest of the introns of the same pre-mRNA had high probabilities of being also affected. This observation points Saf5 as a link between transcription rate and splicing.
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Affiliation(s)
- Sonia Borao
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Montserrat Vega
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Susanna Boronat
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Stefan Hümmer
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - José Ayté
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
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3
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Lam UTF, Nguyen TTT, Raechell R, Yang J, Singer H, Chen ES. A Normalization Protocol Reduces Edge Effect in High-Throughput Analyses of Hydroxyurea Hypersensitivity in Fission Yeast. Biomedicines 2023; 11:2829. [PMID: 37893202 PMCID: PMC10604075 DOI: 10.3390/biomedicines11102829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Edge effect denotes better growth of microbial organisms situated at the edge of the solid agar media. Although the precise reason underlying edge effect is unresolved, it is generally attributed to greater nutrient availability with less competing neighbors at the edge. Nonetheless, edge effect constitutes an unavoidable confounding factor that results in misinterpretation of cell fitness, especially in high-throughput screening experiments widely employed for genome-wide investigation using microbial gene knockout or mutant libraries. Here, we visualize edge effect in high-throughput high-density pinning arrays and report a normalization approach based on colony growth rate to quantify drug (hydroxyurea)-hypersensitivity in fission yeast strains. This normalization procedure improved the accuracy of fitness measurement by compensating cell growth rate discrepancy at different locations on the plate and reducing false-positive and -negative frequencies. Our work thus provides a simple and coding-free solution for a struggling problem in robotics-based high-throughput screening experiments.
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Affiliation(s)
- Ulysses Tsz-Fung Lam
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore; (U.T.-F.L.); (T.T.T.N.); (R.R.)
| | - Thi Thuy Trang Nguyen
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore; (U.T.-F.L.); (T.T.T.N.); (R.R.)
| | - Raechell Raechell
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore; (U.T.-F.L.); (T.T.T.N.); (R.R.)
| | - Jay Yang
- Singer Instruments, Roadwater, Watchet TA23 0RE, UK; (J.Y.); (H.S.)
| | - Harry Singer
- Singer Instruments, Roadwater, Watchet TA23 0RE, UK; (J.Y.); (H.S.)
| | - Ee Sin Chen
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore; (U.T.-F.L.); (T.T.T.N.); (R.R.)
- NUS Center for Cancer Research, National University of Singapore, Singapore 117599, Singapore
- NUS Synthetic Biology for Clinical & Technological Innovation (SynCTI), Life Science Institute, National University of Singapore, Singapore 117456, Singapore
- National University Health System (NUHS), Singapore 119228, Singapore
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4
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Weidemann DE, Holehouse J, Singh A, Grima R, Hauf S. The minimal intrinsic stochasticity of constitutively expressed eukaryotic genes is sub-Poissonian. SCIENCE ADVANCES 2023; 9:eadh5138. [PMID: 37556551 PMCID: PMC10411910 DOI: 10.1126/sciadv.adh5138] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 07/07/2023] [Indexed: 08/11/2023]
Abstract
Gene expression inherently gives rise to stochastic variation ("noise") in the production of gene products. Minimizing noise is crucial for ensuring reliable cellular functions. However, noise cannot be suppressed below a certain intrinsic limit. For constitutively expressed genes, this limit is typically assumed to be Poissonian noise, wherein the variance in mRNA numbers is equal to their mean. Here, we demonstrate that several cell division genes in fission yeast exhibit mRNA variances significantly below this limit. The reduced variance can be explained by a gene expression model incorporating multiple transcription and mRNA degradation steps. Notably, in this sub-Poissonian regime, distinct from Poissonian or super-Poissonian regimes, cytoplasmic noise is effectively suppressed through a higher mRNA export rate. Our findings redefine the lower limit of eukaryotic gene expression noise and uncover molecular requirements for achieving ultralow noise, which is expected to be important for vital cellular functions.
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Affiliation(s)
- Douglas E. Weidemann
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - James Holehouse
- The Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87510, USA
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, DE 19716, USA
- Department of Biomedical Engineering, University of Delaware, Newark, DE 19716, USA
| | - Ramon Grima
- School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Silke Hauf
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
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5
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Weidemann DE, Singh A, Grima R, Hauf S. The minimal intrinsic stochasticity of constitutively expressed eukaryotic genes is sub-Poissonian. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.06.531283. [PMID: 36945401 PMCID: PMC10028819 DOI: 10.1101/2023.03.06.531283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Stochastic variation in gene products ("noise") is an inescapable by-product of gene expression. Noise must be minimized to allow for the reliable execution of cellular functions. However, noise cannot be suppressed beyond an intrinsic lower limit. For constitutively expressed genes, this limit is believed to be Poissonian, meaning that the variance in mRNA numbers cannot be lower than their mean. Here, we show that several cell division genes in fission yeast have mRNA variances significantly below this limit, which cannot be explained by the classical gene expression model for low-noise genes. Our analysis reveals that multiple steps in both transcription and mRNA degradation are essential to explain this sub-Poissonian variance. The sub-Poissonian regime differs qualitatively from previously characterized noise regimes, a hallmark being that cytoplasmic noise is reduced when the mRNA export rate increases. Our study re-defines the lower limit of eukaryotic gene expression noise and identifies molecular requirements for ultra-low noise which are expected to support essential cell functions.
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Affiliation(s)
- Douglas E Weidemann
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, DE 19716, USA
- Department of Biomedical Engineering, University of Delaware, Newark, DE 19716, USA
| | - Ramon Grima
- School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3JR, Scotland, UK
| | - Silke Hauf
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA 24061, USA
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6
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Altuntas V. Diffusion Alignment Coefficient (DAC): A Novel Similarity Metric for Protein-Protein Interaction Network. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2023; 20:894-903. [PMID: 35737632 DOI: 10.1109/tcbb.2022.3185406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Interaction networks can be used to predict the functions of unknown proteins using known interactions and proteins with known functions. Many graph theory or diffusion-based methods have been proposed, using the assumption that the topological properties of a protein in a network are related to its biological function. Here we seek to improve function prediction by finding more similar neighbors with a new diffusion-based alignment technique to overcome the topological information loss of the node. In this study, we introduce the Diffusion Alignment Coefficient (DAC) algorithm, which combines diffusion, longest common subsequence, and longest common substring techniques to measure the similarity of two nodes in protein interaction networks. As a proof of concept, our experiments, conducted on a real PPI networks S.cerevisiae and Homo Sapiens, demonstrated that our method obtained better results than competitors for MIPS and MSigDB Collections hallmark gene set functional categories. This is the first study to develop a measure of node function similarity using alignment to consider the positions of nodes in protein-protein interaction networks. According to the experimental results, the use of spatial information belonging to the nodes in the network has a positive effect on the detection of more functionally similar neighboring nodes.
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7
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Mahrik L, Stefanovie B, Maresova A, Princova J, Kolesar P, Lelkes E, Faux C, Helmlinger D, Prevorovsky M, Palecek JJ. The SAGA histone acetyltransferase module targets SMC5/6 to specific genes. Epigenetics Chromatin 2023; 16:6. [PMID: 36793083 PMCID: PMC9933293 DOI: 10.1186/s13072-023-00480-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 02/02/2023] [Indexed: 02/17/2023] Open
Abstract
BACKGROUND Structural Maintenance of Chromosomes (SMC) complexes are molecular machines driving chromatin organization at higher levels. In eukaryotes, three SMC complexes (cohesin, condensin and SMC5/6) play key roles in cohesion, condensation, replication, transcription and DNA repair. Their physical binding to DNA requires accessible chromatin. RESULTS We performed a genetic screen in fission yeast to identify novel factors required for SMC5/6 binding to DNA. We identified 79 genes of which histone acetyltransferases (HATs) were the most represented. Genetic and phenotypic analyses suggested a particularly strong functional relationship between the SMC5/6 and SAGA complexes. Furthermore, several SMC5/6 subunits physically interacted with SAGA HAT module components Gcn5 and Ada2. As Gcn5-dependent acetylation facilitates the accessibility of chromatin to DNA-repair proteins, we first analysed the formation of DNA-damage-induced SMC5/6 foci in the Δgcn5 mutant. The SMC5/6 foci formed normally in Δgcn5, suggesting SAGA-independent SMC5/6 localization to DNA-damaged sites. Next, we used Nse4-FLAG chromatin-immunoprecipitation (ChIP-seq) analysis in unchallenged cells to assess SMC5/6 distribution. A significant portion of SMC5/6 accumulated within gene regions in wild-type cells, which was reduced in Δgcn5 and Δada2 mutants. The drop in SMC5/6 levels was also observed in gcn5-E191Q acetyltransferase-dead mutant. CONCLUSION Our data show genetic and physical interactions between SMC5/6 and SAGA complexes. The ChIP-seq analysis suggests that SAGA HAT module targets SMC5/6 to specific gene regions and facilitates their accessibility for SMC5/6 loading.
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Affiliation(s)
- L Mahrik
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, 61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - B Stefanovie
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, 61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - A Maresova
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, 12800, Prague, Czech Republic
| | - J Princova
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, 12800, Prague, Czech Republic
| | - P Kolesar
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, 61137, Brno, Czech Republic
| | - E Lelkes
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, 61137, Brno, Czech Republic
| | - C Faux
- Centre de Recherche en Biologie Cellulaire de Montpellier, University of Montpellier, CNRS, 1919 Route de Mende, 34293, Montpellier Cedex 05, France
| | - D Helmlinger
- Centre de Recherche en Biologie Cellulaire de Montpellier, University of Montpellier, CNRS, 1919 Route de Mende, 34293, Montpellier Cedex 05, France
| | - M Prevorovsky
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, 12800, Prague, Czech Republic.
| | - J J Palecek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlarska 2, 61137, Brno, Czech Republic.
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic.
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic.
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8
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Li Y, Molyneaux N, Zhang H, Zhou G, Kerr C, Adams MD, Berkner KL, Runge KW. A multiplexed, three-dimensional pooling and next-generation sequencing strategy for creating barcoded mutant arrays: construction of a Schizosaccharomyces pombe transposon insertion library. Nucleic Acids Res 2022; 50:e102. [PMID: 35766443 PMCID: PMC9508820 DOI: 10.1093/nar/gkac546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/02/2022] [Accepted: 06/12/2022] [Indexed: 11/14/2022] Open
Abstract
Arrayed libraries of defined mutants have been used to elucidate gene function in the post-genomic era. Yeast haploid gene deletion libraries have pioneered this effort, but are costly to construct, do not reveal phenotypes that may occur with partial gene function and lack essential genes required for growth. We therefore devised an efficient method to construct a library of barcoded insertion mutants with a wider range of phenotypes that can be generalized to other organisms or collections of DNA samples. We developed a novel but simple three-dimensional pooling and multiplexed sequencing approach that leveraged sequence information to reduce the number of required sequencing reactions by orders of magnitude, and were able to identify the barcode sequences and DNA insertion sites of 4391 Schizosaccharomyces pombe insertion mutations with only 40 sequencing preparations. The insertion mutations are in the genes and untranslated regions of nonessential, essential and noncoding RNA genes, and produced a wider range of phenotypes compared to the cognate deletion mutants, including novel phenotypes. This mutant library represents both a proof of principle for an efficient method to produce novel mutant libraries and a valuable resource for the S. pombe research community.
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Affiliation(s)
- Yanhui Li
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA
- Department of Genetics and Genomic Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Neil Molyneaux
- Department of Genetics and Genomic Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Haitao Zhang
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA
| | - Gang Zhou
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA
| | - Carly Kerr
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA
| | - Mark D Adams
- Department of Genetics and Genomic Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Kathleen L Berkner
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA
| | - Kurt W Runge
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA
- Department of Genetics and Genomic Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH 44195, USA
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9
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Chatfield-Reed K, Marno Jones K, Shah F, Chua G. Genetic-interaction screens uncover novel biological roles and regulators of transcription factors in fission yeast. G3 GENES|GENOMES|GENETICS 2022; 12:6655692. [PMID: 35924983 PMCID: PMC9434175 DOI: 10.1093/g3journal/jkac194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 07/20/2022] [Indexed: 12/05/2022]
Abstract
In Schizosaccharomyces pombe, systematic analyses of single transcription factor deletion or overexpression strains have made substantial advances in determining the biological roles and target genes of transcription factors, yet these characteristics are still relatively unknown for over a quarter of them. Moreover, the comprehensive list of proteins that regulate transcription factors remains incomplete. To further characterize Schizosaccharomyces pombe transcription factors, we performed synthetic sick/lethality and synthetic dosage lethality screens by synthetic genetic array. Examination of 2,672 transcription factor double deletion strains revealed a sick/lethality interaction frequency of 1.72%. Phenotypic analysis of these sick/lethality strains revealed potential cell cycle roles for several poorly characterized transcription factors, including SPBC56F2.05, SPCC320.03, and SPAC3C7.04. In addition, we examined synthetic dosage lethality interactions between 14 transcription factors and a miniarray of 279 deletion strains, observing a synthetic dosage lethality frequency of 4.99%, which consisted of known and novel transcription factor regulators. The miniarray contained deletions of genes that encode primarily posttranslational-modifying enzymes to identify putative upstream regulators of the transcription factor query strains. We discovered that ubiquitin ligase Ubr1 and its E2/E3-interacting protein, Mub1, degrade the glucose-responsive transcriptional repressor Scr1. Loss of ubr1+ or mub1+ increased Scr1 protein expression, which resulted in enhanced repression of flocculation through Scr1. The synthetic dosage lethality screen also captured interactions between Scr1 and 2 of its known repressors, Sds23 and Amk2, each affecting flocculation through Scr1 by influencing its nuclear localization. Our study demonstrates that sick/lethality and synthetic dosage lethality screens can be effective in uncovering novel functions and regulators of Schizosaccharomyces pombe transcription factors.
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Affiliation(s)
- Kate Chatfield-Reed
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada
| | - Kurtis Marno Jones
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada
| | - Farah Shah
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada
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10
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Al-Anzi BF, Khajah M, Fakhraldeen SA. Predicting and explaining the impact of genetic disruptions and interactions on organismal viability. Bioinformatics 2022; 38:4088-4099. [PMID: 35861390 PMCID: PMC9438956 DOI: 10.1093/bioinformatics/btac519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/30/2022] [Accepted: 07/20/2022] [Indexed: 12/24/2022] Open
Abstract
MOTIVATION Existing computational models can predict single- and double-mutant fitness but they do have limitations. First, they are often tested via evaluation metrics that are inappropriate for imbalanced datasets. Second, all of them only predict a binary outcome (viable or not, and negatively interacting or not). Third, most are uninterpretable black box machine learning models. RESULTS Budding yeast datasets were used to develop high-performance Multinomial Regression (MN) models capable of predicting the impact of single, double and triple genetic disruptions on viability. These models are interpretable and give realistic non-binary predictions and can predict negative genetic interactions (GIs) in triple-gene knockouts. They are based on a limited set of gene features and their predictions are influenced by the probability of target gene participating in molecular complexes or pathways. Furthermore, the MN models have utility in other organisms such as fission yeast, fruit flies and humans, with the single gene fitness MN model being able to distinguish essential genes necessary for cell-autonomous viability from those required for multicellular survival. Finally, our models exceed the performance of previous models, without sacrificing interpretability. AVAILABILITY AND IMPLEMENTATION All code and processed datasets used to generate results and figures in this manuscript are available at our Github repository at https://github.com/KISRDevelopment/cell_viability_paper. The repository also contains a link to the GI prediction website that lets users search for GIs using the MN models. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
| | | | - Saja A Fakhraldeen
- Ecosystem-based Management of Marine Resources Program, Kuwait Institute for Scientific Research, Safat, 13109, Kuwait
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11
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Esposito E, Weidemann DE, Rogers JM, Morton CM, Baybay EK, Chen J, Hauf S. Mitotic checkpoint gene expression is tuned by codon usage bias. EMBO J 2022; 41:e107896. [PMID: 35811551 PMCID: PMC9340482 DOI: 10.15252/embj.2021107896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/30/2022] [Accepted: 06/06/2022] [Indexed: 11/09/2022] Open
Abstract
The mitotic checkpoint (also called spindle assembly checkpoint, SAC) is a signaling pathway that safeguards proper chromosome segregation. Correct functioning of the SAC depends on adequate protein concentrations and appropriate stoichiometries between SAC proteins. Yet very little is known about the regulation of SAC gene expression. Here, we show in the fission yeast Schizosaccharomyces pombe that a combination of short mRNA half-lives and long protein half-lives supports stable SAC protein levels. For the SAC genes mad2+ and mad3+ , their short mRNA half-lives are caused, in part, by a high frequency of nonoptimal codons. In contrast, mad1+ mRNA has a short half-life despite a higher frequency of optimal codons, and despite the lack of known RNA-destabilizing motifs. Hence, different SAC genes employ different strategies of expression. We further show that Mad1 homodimers form co-translationally, which may necessitate a certain codon usage pattern. Taken together, we propose that the codon usage of SAC genes is fine-tuned to ensure proper SAC function. Our work shines light on gene expression features that promote spindle assembly checkpoint function and suggests that synonymous mutations may weaken the checkpoint.
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Affiliation(s)
- Eric Esposito
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Douglas E Weidemann
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Jessie M Rogers
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Claire M Morton
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Erod Keaton Baybay
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Jing Chen
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Silke Hauf
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
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12
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Synthetic negative genome screen of the GPN-loop GTPase NPA3 in Saccharomyces cerevisiae. Curr Genet 2022; 68:343-360. [PMID: 35660944 DOI: 10.1007/s00294-022-01243-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 04/21/2022] [Accepted: 04/30/2022] [Indexed: 11/03/2022]
Abstract
The GPN-loop GTPase Npa3 is encoded by an essential gene in the yeast Saccharomyces cerevisiae. Npa3 plays a critical role in the assembly and nuclear accumulation of RNA polymerase II (RNAPII), a function that may explain its essentiality. Genetic interactions describe the extent to which a mutation in a particular gene affects a specific phenotype when co-occurring with an alteration in a second gene. Discovering synthetic negative genetic interactions has long been used as a tool to delineate the functional relatedness between pairs of genes participating in common or compensatory biological pathways. Previously, our group showed that nuclear targeting and transcriptional activity of RNAPII were unaffected in cells expressing exclusively a C-terminal truncated mutant version of Npa3 (npa3∆C) lacking the last 106 residues naturally absent from the single GPN protein in Archaea, but universally conserved in all Npa3 orthologs of eukaryotes. To gain insight into novel cellular functions for Npa3, we performed here a genome-wide Synthetic Genetic Array (SGA) study coupled to bulk fluorescence monitoring to identify negative genetic interactions of NPA3 by crossing an npa3∆C strain with a 4,389 nonessential gene-deletion collection. This genetic screen revealed previously unknown synthetic negative interactions between NPA3 and 15 genes. Our results revealed that the Npa3 C-terminal tail extension regulates the participation of this essential GTPase in previously unknown biological processes related to mitochondrial homeostasis and ribosome biogenesis.
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13
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Opalko HE, Miller KE, Kim HS, Vargas-Garcia CA, Singh A, Keogh MC, Moseley JB. Arf6 anchors Cdr2 nodes at the cell cortex to control cell size at division. J Cell Biol 2022; 221:e202109152. [PMID: 34958661 PMCID: PMC8931934 DOI: 10.1083/jcb.202109152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/12/2021] [Accepted: 12/02/2021] [Indexed: 12/25/2022] Open
Abstract
Fission yeast cells prevent mitotic entry until a threshold cell surface area is reached. The protein kinase Cdr2 contributes to this size control system by forming multiprotein nodes that inhibit Wee1 at the medial cell cortex. Cdr2 node anchoring at the cell cortex is not fully understood. Through a genomic screen, we identified the conserved GTPase Arf6 as a component of Cdr2 signaling. Cells lacking Arf6 failed to divide at a threshold surface area and instead shifted to volume-based divisions at increased overall size. Arf6 stably localized to Cdr2 nodes in its GTP-bound but not GDP-bound state, and its guanine nucleotide exchange factor (GEF), Syt22, was required for both Arf6 node localization and proper size at division. In arf6Δ mutants, Cdr2 nodes detached from the membrane and exhibited increased dynamics. These defects were enhanced when arf6Δ was combined with other node mutants. Our work identifies a regulated anchor for Cdr2 nodes that is required for cells to sense surface area.
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Affiliation(s)
- Hannah E. Opalko
- Department of Biochemistry and Cell Biology, the Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Kristi E. Miller
- Department of Biochemistry and Cell Biology, the Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Hyun-Soo Kim
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY
| | - Cesar Augusto Vargas-Garcia
- Grupo de Investigación en Sistemas Agropecuarios Sostenibles, Corporación Colombiana de Investigación Agropecuaria – AGROSAVIA, Bogotá, Colombia
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, DE
| | | | - James B. Moseley
- Department of Biochemistry and Cell Biology, the Geisel School of Medicine at Dartmouth, Hanover, NH
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14
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Verma K, Verma M, Chaphalkar A, Chakraborty K. Recent advances in understanding the role of proteostasis. Fac Rev 2021; 10:72. [PMID: 34632458 PMCID: PMC8483240 DOI: 10.12703/r/10-72] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Maintenance of a functional proteome is achieved through the mechanism of proteostasis that involves precise coordination between molecular machineries assisting a protein from its conception to demise. Although each organelle within a cell has its own set of proteostasis machinery, inter-organellar communication and cell non-autonomous signaling bring forth the multidimensional nature of the proteostasis network. Exposure to extrinsic and intrinsic stressors can challenge the proteostasis network, leading to the accumulation of aberrant proteins or a decline in the proteostasis components, as seen during aging and in several diseases. Here, we summarize recent advances in understanding the role of proteostasis and its regulation in aging and disease, including monogenetic and infectious diseases. We highlight some of the emerging as well as unresolved questions in proteostasis that need to be addressed to overcome pathologies associated with damaged proteins and to promote healthy aging.
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Affiliation(s)
- Kanika Verma
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, Delhi, India
- Academy of Scientific and Innovative Research, CSIR-HRDC, Ghaziabad, Uttar Pradesh, India
| | - Monika Verma
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, Delhi, India
- Academy of Scientific and Innovative Research, CSIR-HRDC, Ghaziabad, Uttar Pradesh, India
| | - Aseem Chaphalkar
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, Delhi, India
- Academy of Scientific and Innovative Research, CSIR-HRDC, Ghaziabad, Uttar Pradesh, India
| | - Kausik Chakraborty
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, Delhi, India
- Academy of Scientific and Innovative Research, CSIR-HRDC, Ghaziabad, Uttar Pradesh, India
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15
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Stirpe A, Guidotti N, Northall SJ, Kilic S, Hainard A, Vadas O, Fierz B, Schalch T. SUV39 SET domains mediate crosstalk of heterochromatic histone marks. eLife 2021; 10:62682. [PMID: 34524082 PMCID: PMC8443253 DOI: 10.7554/elife.62682] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 08/31/2021] [Indexed: 12/21/2022] Open
Abstract
The SUV39 class of methyltransferase enzymes deposits histone H3 lysine 9 di- and trimethylation (H3K9me2/3), the hallmark of constitutive heterochromatin. How these enzymes are regulated to mark specific genomic regions as heterochromatic is poorly understood. Clr4 is the sole H3K9me2/3 methyltransferase in the fission yeast Schizosaccharomyces pombe, and recent evidence suggests that ubiquitination of lysine 14 on histone H3 (H3K14ub) plays a key role in H3K9 methylation. However, the molecular mechanism of this regulation and its role in heterochromatin formation remain to be determined. Our structure-function approach shows that the H3K14ub substrate binds specifically and tightly to the catalytic domain of Clr4, and thereby stimulates the enzyme by over 250-fold. Mutations that disrupt this mechanism lead to a loss of H3K9me2/3 and abolish heterochromatin silencing similar to clr4 deletion. Comparison with mammalian SET domain proteins suggests that the Clr4 SET domain harbors a conserved sensor for H3K14ub, which mediates licensing of heterochromatin formation.
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Affiliation(s)
- Alessandro Stirpe
- Department of Molecular Biology, Faculty of Science, University of Geneva, Geneva, Switzerland
| | - Nora Guidotti
- Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Sarah J Northall
- Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, United Kingdom.,Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - Sinan Kilic
- Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Alexandre Hainard
- University Medical Center, University of Geneva, Geneva, Switzerland
| | - Oscar Vadas
- School of Pharmaceutical Sciences, Faculty of Science, University of Geneva, Geneva, Switzerland
| | - Beat Fierz
- Institute of Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Thomas Schalch
- Department of Molecular Biology, Faculty of Science, University of Geneva, Geneva, Switzerland.,Leicester Institute for Structural and Chemical Biology, University of Leicester, Leicester, United Kingdom.,Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
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16
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Schmücker A, Lei B, Lorković ZJ, Capella M, Braun S, Bourguet P, Mathieu O, Mechtler K, Berger F. Crosstalk between H2A variant-specific modifications impacts vital cell functions. PLoS Genet 2021; 17:e1009601. [PMID: 34086674 PMCID: PMC8208582 DOI: 10.1371/journal.pgen.1009601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/16/2021] [Accepted: 05/14/2021] [Indexed: 12/15/2022] Open
Abstract
Selection of C-terminal motifs participated in evolution of distinct histone H2A variants. Hybrid types of variants combining motifs from distinct H2A classes are extremely rare. This suggests that the proximity between the motif cases interferes with their function. We studied this question in flowering plants that evolved sporadically a hybrid H2A variant combining the SQ motif of H2A.X that participates in the DNA damage response with the KSPK motif of H2A.W that stabilizes heterochromatin. Our inventory of PTMs of H2A.W variants showed that in vivo the cell cycle-dependent kinase CDKA phosphorylates the KSPK motif of H2A.W but only in absence of an SQ motif. Phosphomimicry of KSPK prevented DNA damage response by the SQ motif of the hybrid H2A.W/X variant. In a synthetic yeast expressing the hybrid H2A.W/X variant, phosphorylation of KSPK prevented binding of the BRCT-domain protein Mdb1 to phosphorylated SQ and impaired response to DNA damage. Our findings illustrate that PTMs mediate interference between the function of H2A variant specific C-terminal motifs. Such interference could explain the mutual exclusion of motifs that led to evolution of H2A variants.
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Affiliation(s)
- Anna Schmücker
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Bingkun Lei
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Zdravko J. Lorković
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Matías Capella
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University of Munich, Planegg-Martinsried, Germany
| | - Sigurd Braun
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University of Munich, Planegg-Martinsried, Germany
- International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany
| | - Pierre Bourguet
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
- CNRS, Université Clermont Auvergne, Inserm, Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - Olivier Mathieu
- CNRS, Université Clermont Auvergne, Inserm, Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - Karl Mechtler
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
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17
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Shan CM, Bao K, Diedrich J, Chen X, Lu C, Yates JR, Jia S. The INO80 Complex Regulates Epigenetic Inheritance of Heterochromatin. Cell Rep 2020; 33:108561. [PMID: 33378674 PMCID: PMC7896557 DOI: 10.1016/j.celrep.2020.108561] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/31/2020] [Accepted: 12/03/2020] [Indexed: 12/21/2022] Open
Abstract
One key aspect of epigenetic inheritance is that chromatin structures can be stably inherited through generations after the removal of the signals that establish such structures. In fission yeast, the RNA interference (RNAi) pathway is critical for the targeting of histone methyltransferase Clr4 to pericentric repeats to establish heterochromatin. However, pericentric heterochromatin cannot be properly inherited in the absence of RNAi, suggesting the existence of mechanisms that counteract chromatin structure inheritance. Here, we show that mutations of components of the INO80 chromatin-remodeling complex allow pericentric heterochromatin inheritance in RNAi mutants. The ability of INO80 to counter heterochromatin inheritance is attributed to one subunit, Iec5, which promotes histone turnover at heterochromatin but has little effects on nucleosome positioning at heterochromatin, gene expression, or the DNA damage response. These analyses demonstrate the importance of the INO80 chromatin-remodeling complex in controlling heterochromatin inheritance and maintaining the proper heterochromatin landscape of the genome.
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Affiliation(s)
- Chun-Min Shan
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Kehan Bao
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Jolene Diedrich
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xiao Chen
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Chao Lu
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA; Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Songtao Jia
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
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18
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Sánchez-Mir L, Fraile R, Ayté J, Hidalgo E. Phosphorylation of the Transcription Factor Atf1 at Multiple Sites by the MAP Kinase Sty1 Controls Homologous Recombination and Transcription. J Mol Biol 2020; 432:5430-5446. [PMID: 32795531 DOI: 10.1016/j.jmb.2020.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/31/2020] [Accepted: 08/04/2020] [Indexed: 01/21/2023]
Abstract
Transcription factors are often the downstream effectors of signaling cascades. In fission yeast, the transcription factor Atf1 is phosphorylated by the MAP kinase Sty1 under several environmental stressors to promote transcription initiation of stress genes. However, Sty1 and Atf1 have also been involved in other cellular processes such as homologous recombination at hotspots, ste11 gene expression during mating and meiosis, or regulation of fbp1 gene transcription under glucose starvation conditions. Using different phospho-mutants of Atf1, we have investigated the role of Atf1 phosphorylation by Sty1 in those biological processes. An Atf1 mutant lacking the canonical MAP kinase phosphorylation sites cannot activate fbp1 transcription when glucose is depleted, but it is still able to induce recombination at ade6.M26 and to induce ste11 after nitrogen depletion; in these last cases, Sty1 is still required, suggesting that additional non-canonical sites are activating the transcription factor. In all cases, an Atf1 phosphomimetic mutant bypasses the requirement of the Sty1 kinase in these diverse biological processes, highlighting the essential role of the DNA binding factor Atf1 on chromatin remodeling and cell adaptation to nutritional changes. We propose that post-translational modifications of Atf1 by Sty1, either at canonical or non-canonical sites, are sufficient to activate some of the functions of Atf1, those involving chromatin remodeling and transcription initiation. However, in the case of fbp1 where Atf1 acts synergistically with other transcription factors, elimination of the canonical sites is sufficient to hamper some of the interactions required in this complex scenario and to impair transcription initiation.
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Affiliation(s)
- Laura Sánchez-Mir
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Rodrigo Fraile
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - José Ayté
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain.
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19
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Tutuncuoglu B, Krogan NJ. Mapping genetic interactions in cancer: a road to rational combination therapies. Genome Med 2019; 11:62. [PMID: 31640753 PMCID: PMC6805649 DOI: 10.1186/s13073-019-0680-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 10/16/2019] [Indexed: 01/08/2023] Open
Abstract
The discovery of synthetic lethal interactions between poly (ADP-ribose) polymerase (PARP) inhibitors and BRCA genes, which are involved in homologous recombination, led to the approval of PARP inhibition as a monotherapy for patients with BRCA1/2-mutated breast or ovarian cancer. Studies following the initial observation of synthetic lethality demonstrated that the reach of PARP inhibitors is well beyond just BRCA1/2 mutants. Insights into the mechanisms of action of anticancer drugs are fundamental for the development of targeted monotherapies or rational combination treatments that will synergize to promote cancer cell death and overcome mechanisms of resistance. The development of targeted therapeutic agents is premised on mapping the physical and functional dependencies of mutated genes in cancer. An important part of this effort is the systematic screening of genetic interactions in a variety of cancer types. Until recently, genetic-interaction screens have relied either on the pairwise perturbations of two genes or on the perturbation of genes of interest combined with inhibition by commonly used anticancer drugs. Here, we summarize recent advances in mapping genetic interactions using targeted, genome-wide, and high-throughput genetic screens, and we discuss the therapeutic insights obtained through such screens. We further focus on factors that should be considered in order to develop a robust analysis pipeline. Finally, we discuss the integration of functional interaction data with orthogonal methods and suggest that such approaches will increase the reach of genetic-interaction screens for the development of rational combination therapies.
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Affiliation(s)
- Beril Tutuncuoglu
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, 16th Street, Mission Bay Campus, San Francisco, CA, 94158-2140, USA.,The J. David Gladstone Institutes, Owens Street, San Francisco, CA, 94158, USA.,Quantitative Biosciences Institute, University of California, San Francisco, 4th Street, San Francisco, CA, 94158, USA.,Cancer Cell Map Initiative (CCMI), La Jolla and San Francisco, CA, USA
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, 16th Street, Mission Bay Campus, San Francisco, CA, 94158-2140, USA. .,The J. David Gladstone Institutes, Owens Street, San Francisco, CA, 94158, USA. .,Quantitative Biosciences Institute, University of California, San Francisco, 4th Street, San Francisco, CA, 94158, USA. .,Cancer Cell Map Initiative (CCMI), La Jolla and San Francisco, CA, USA.
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20
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Takeda A, Saitoh S, Ohkura H, Sawin KE, Goshima G. Identification of 15 New Bypassable Essential Genes of Fission Yeast. Cell Struct Funct 2019; 44:113-119. [PMID: 31474649 PMCID: PMC6877344 DOI: 10.1247/csf.19025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Every organism has a different set of genes essential for its viability. This indicates that an organism can become tolerant to the loss of an essential gene under certain circumstances during evolution, via the manifestation of 'masked' alternative mechanisms. In our quest to systematically uncover masked mechanisms in eukaryotic cells, we developed an extragenic suppressor screening method using haploid spores deleted of an essential gene in the fission yeast Schizosaccharomyces pombe. We screened for the 'bypass' suppressors of lethality of 92 randomly selected genes that are essential for viability in standard laboratory culture conditions. Remarkably, extragenic mutations bypassed the essentiality of as many as 20 genes (22%), 15 of which have not been previously reported. Half of the bypass-suppressible genes were involved in mitochondria function; we also identified multiple genes regulating RNA processing. 18 suppressible genes were conserved in the budding yeast Saccharomyces cerevisiae, but 13 of them were non-essential in that species. These trends suggest that essentiality bypass is not a rare event and that each organism may be endowed with secondary or backup mechanisms that can substitute for primary mechanisms in various biological processes. Furthermore, the robustness of our simple spore-based methodology paves the way for genome-scale screening.Key words: Schizosaccharomyces pombe, extragenic suppressor screening, bypass of essentiality (BOE), cut7 (kinesin-5), hul5 (E3 ubiquitin ligase).
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Affiliation(s)
- Aoi Takeda
- Division of Biological Science, Graduate School of Science, Nagoya
University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Shigeaki Saitoh
- Division of Cell Biology, Institute of Life Science, Kurume
University, Kurume, Fukuoka 830-0011, Japan
| | - Hiroyuki Ohkura
- Wellcome Centre for Cell Biology, School of Biological Sciences,
University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9
3BF, UK
| | - Kenneth E. Sawin
- Wellcome Centre for Cell Biology, School of Biological Sciences,
University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9
3BF, UK
| | - Gohta Goshima
- Division of Biological Science, Graduate School of Science, Nagoya
University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan,Correspondence should be addressed to:
: Phone: +81 52-788-6175
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21
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Folco HD, McCue A, Balachandran V, Grewal SIS. Cohesin Impedes Heterochromatin Assembly in Fission Yeast Cells Lacking Pds5. Genetics 2019; 213:127-141. [PMID: 31278118 PMCID: PMC6727797 DOI: 10.1534/genetics.119.302256] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/24/2019] [Indexed: 01/05/2023] Open
Abstract
The fission yeast Schizosaccharomyces pombe is a powerful genetic model system for uncovering fundamental principles of heterochromatin assembly and epigenetic inheritance of chromatin states. Heterochromatin defined by histone H3 lysine 9 methylation and HP1 proteins coats large chromosomal domains at centromeres, telomeres, and the mating-type (mat) locus. Although genetic and biochemical studies have provided valuable insights into heterochromatin assembly, many key mechanistic details remain unclear. Here, we use a sensitized reporter system at the mat locus to screen for factors affecting heterochromatic silencing. In addition to known components of heterochromatin assembly pathways, our screen identified eight new factors including the cohesin-associated protein Pds5. We find that Pds5 enriched throughout heterochromatin domains is required for proper maintenance of heterochromatin. This function of Pds5 requires its associated Eso1 acetyltransferase, which is implicated in the acetylation of cohesin. Indeed, introducing an acetylation-mimicking mutation in a cohesin subunit suppresses defects in heterochromatin assembly in pds5∆ and eso1∆ cells. Our results show that in cells lacking Pds5, cohesin interferes with heterochromatin assembly. Supporting this, eliminating cohesin from the mat locus in the pds5∆ mutant restores both heterochromatin assembly and gene silencing. These analyses highlight an unexpected requirement for Pds5 in ensuring proper coordination between cohesin and heterochromatin factors to effectively maintain gene silencing.
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Affiliation(s)
- H Diego Folco
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Andrea McCue
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Vanivilasini Balachandran
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
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22
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Lie S, Banks P, Lawless C, Lydall D, Petersen J. The contribution of non-essential Schizosaccharomyces pombe genes to fitness in response to altered nutrient supply and target of rapamycin activity. Open Biol 2019; 8:rsob.180015. [PMID: 29720420 PMCID: PMC5990653 DOI: 10.1098/rsob.180015] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 04/06/2018] [Indexed: 12/12/2022] Open
Abstract
Nutrient fluctuations in the cellular environment promote changes in cell metabolism and growth to adapt cell proliferation accordingly. The target of rapamycin (TOR) signalling network plays a key role in the coordination of growth and cell proliferation with the nutrient environment and, importantly, nutrient limitation reduces TOR complex 1 (TORC1) signalling. We have performed global quantitative fitness profiling of the collection of Schizosaccharomyces pombe strains from which non-essential genes have been deleted. We identified genes that regulate fitness when cells are grown in a nutrient-rich environment compared with minimal environments, with varying nitrogen sources including ammonium, glutamate and proline. In addition, we have performed the first global screen for genes that regulate fitness when both TORC1 and TORC2 signalling is reduced by Torin1. Analysis of genes whose deletions altered fitness when nutrients were limited, or when TOR signalling was compromised, identified a large number of genes that regulate transmembrane transport, transcription and chromatin organization/regulation and vesicle-mediated transport. The ability to tolerate reduced TOR signalling placed demands upon a large number of biological processes including autophagy, mRNA metabolic processing and nucleocytoplasmic transport. Importantly, novel biological processes and all processes known to be regulated by TOR were identified in our screens. In addition, deletion of 62 genes conserved in humans gave rise to strong sensitivity or resistance to Torin1, and 29 of these 62 genes have novel links to TOR signalling. The identification of chromatin and transcriptional regulation, nutritional uptake and transport pathways in this powerful genetic model now paves the way for a molecular understanding of how cells adapt to the chronic and acute fluctuations in nutrient supply that all eukaryotes experience at some stage, and which is a key feature of cancer cells within solid tumours.
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Affiliation(s)
- Shervi Lie
- Flinders Centre for Innovation in Cancer, College of Medicine & Public Health, Flinders University, Bedford Park, Adelaide, South Australia 5042, Australia
| | - Peter Banks
- High Throughput Screening Facility, Newcastle Biomedicine, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Conor Lawless
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - David Lydall
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - Janni Petersen
- Flinders Centre for Innovation in Cancer, College of Medicine & Public Health, Flinders University, Bedford Park, Adelaide, South Australia 5042, Australia .,South Australia Health and Medical Research Institute, North Terrace, PO Box 11060, Adelaide, South Australia 5000, Australia
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23
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Bao K, Shan CM, Moresco J, Yates J, Jia S. Anti-silencing factor Epe1 associates with SAGA to regulate transcription within heterochromatin. Genes Dev 2018; 33:116-126. [PMID: 30573453 PMCID: PMC6317313 DOI: 10.1101/gad.318030.118] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022]
Abstract
In this study, Bao et al. investigated how transcription is regulated within heterochromatin in fission yeast. They show that overexpressed Epe1 associates with SAGA and recruits SAGA to heterochromatin regions (which leads to an increase in histone acetylation, transcription of repeats, and the disruption of heterochromatin) and that Epe1 recruits SAGA to regulate transcription within heterochromatin when expressed at normal levels. Heterochromatin is a highly condensed form of chromatin that silences gene transcription. Although high levels of transcriptional activities disrupt heterochromatin, transcription of repetitive DNA elements and subsequent processing of the transcripts by the RNAi machinery are required for heterochromatin assembly. In fission yeast, a JmjC domain protein, Epe1, promotes transcription of DNA repeats to facilitate heterochromatin formation, but overexpression of Epe1 leads to heterochromatin defects. However, the molecular function of Epe1 is not well understood. By screening the fission yeast deletion library, we found that heterochromatin defects associated with Epe1 overexpression are alleviated by mutations of the SAGA histone acetyltransferase complex. Overexpressed Epe1 associates with SAGA and recruits SAGA to heterochromatin regions, which leads to increased histone acetylation, transcription of repeats, and the disruption of heterochromatin. At its normal expression levels, Epe1 also associates with SAGA, albeit weakly. Such interaction regulates histone acetylation levels at heterochromatin and promotes transcription of repeats for heterochromatin assembly. Our results also suggest that increases of certain chromatin protein levels, which frequently occur in cancer cells, might strengthen relatively weak interactions to affect the epigenetic landscape.
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Affiliation(s)
- Kehan Bao
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Chun-Min Shan
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - James Moresco
- Department of Molecular Medicine and Neurobiology, The Scripps Research Institute, La Jolla, California 92037, USA
| | - John Yates
- Department of Molecular Medicine and Neurobiology, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Songtao Jia
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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24
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Shen JP, Ideker T. Synthetic Lethal Networks for Precision Oncology: Promises and Pitfalls. J Mol Biol 2018; 430:2900-2912. [PMID: 29932943 PMCID: PMC6097899 DOI: 10.1016/j.jmb.2018.06.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/10/2018] [Accepted: 06/13/2018] [Indexed: 12/22/2022]
Abstract
Synthetic lethal interactions, in which the simultaneous loss of function of two genes produces a lethal phenotype, are being explored as a means to therapeutically exploit cancer-specific vulnerabilities and expand the scope of precision oncology. Currently, three Food and Drug Administration-approved drugs work by targeting the synthetic lethal interaction between BRCA1/2 and PARP. This review examines additional efforts to discover networks of synthetic lethal interactions and discusses both challenges and opportunities regarding the translation of new synthetic lethal interactions into the clinic.
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Affiliation(s)
- John Paul Shen
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Cancer Cell Map Initiative, USA.
| | - Trey Ideker
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Cancer Cell Map Initiative, USA
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25
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Horlbeck MA, Xu A, Wang M, Bennett NK, Park CY, Bogdanoff D, Adamson B, Chow ED, Kampmann M, Peterson TR, Nakamura K, Fischbach MA, Weissman JS, Gilbert LA. Mapping the Genetic Landscape of Human Cells. Cell 2018; 174:953-967.e22. [PMID: 30033366 DOI: 10.1016/j.cell.2018.06.010] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 03/08/2018] [Accepted: 06/05/2018] [Indexed: 12/31/2022]
Abstract
Seminal yeast studies have established the value of comprehensively mapping genetic interactions (GIs) for inferring gene function. Efforts in human cells using focused gene sets underscore the utility of this approach, but the feasibility of generating large-scale, diverse human GI maps remains unresolved. We developed a CRISPR interference platform for large-scale quantitative mapping of human GIs. We systematically perturbed 222,784 gene pairs in two cancer cell lines. The resultant maps cluster functionally related genes, assigning function to poorly characterized genes, including TMEM261, a new electron transport chain component. Individual GIs pinpoint unexpected relationships between pathways, exemplified by a specific cholesterol biosynthesis intermediate whose accumulation induces deoxynucleotide depletion, causing replicative DNA damage and a synthetic-lethal interaction with the ATR/9-1-1 DNA repair pathway. Our map provides a broad resource, establishes GI maps as a high-resolution tool for dissecting gene function, and serves as a blueprint for mapping the genetic landscape of human cells.
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Affiliation(s)
- Max A Horlbeck
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Albert Xu
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Min Wang
- Department of Bioengineering and ChEM-H, Stanford University, Stanford, CA 94305, USA
| | - Neal K Bennett
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Chong Y Park
- Innovative Genomics Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Derek Bogdanoff
- Center for Advanced Technology, Department of Biophysics and Biochemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Britt Adamson
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Eric D Chow
- Center for Advanced Technology, Department of Biophysics and Biochemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Martin Kampmann
- Institute for Neurodegenerative Diseases and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Tim R Peterson
- Department of Internal Medicine, Division of Bone and Mineral Diseases, and Department of Genetics, Institute for Public Health, Washington University School of Medicine, 425 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Ken Nakamura
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Michael A Fischbach
- Department of Bioengineering and ChEM-H, Stanford University, Stanford, CA 94305, USA
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Luke A Gilbert
- Department of Urology, University of California, San Francisco, San Francisco, CA 94158, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA.
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26
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A Cloning-Free Method for CRISPR/Cas9-Mediated Genome Editing in Fission Yeast. G3-GENES GENOMES GENETICS 2018; 8:2067-2077. [PMID: 29703785 PMCID: PMC5982833 DOI: 10.1534/g3.118.200164] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The CRISPR/Cas9 system, which relies on RNA‐guided DNA cleavage to induce site-specific DNA double-strand breaks, is a powerful tool for genome editing. This system has been successfully adapted for the fission yeast Schizosaccharomyces pombe by expressing Cas9 and the single-guide RNA (sgRNA) from a plasmid. In the procedures published to date, the cloning step that introduces a specific sgRNA target sequence into the plasmid is the most tedious and time-consuming. To increase the efficiency of applying the CRISPR/Cas9 system in fission yeast, we here developed a cloning-free procedure that uses gap repair in fission yeast cells to assemble two linear DNA fragments, a gapped Cas9-encoding plasmid and a PCR-amplified sgRNA insert, into a circular plasmid. Both fragments contain only a portion of the ura4 or bsdMX marker so that only the correctly assembled plasmid can confer uracil prototrophy or blasticidin resistance. We show that this gap-repair-based and cloning-free CRISPR/Cas9 procedure permits rapid and efficient point mutation knock-in, endogenous N-terminal tagging, and genomic sequence deletion in fission yeast.
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27
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Sardi M, Gasch AP. Genetic background effects in quantitative genetics: gene-by-system interactions. Curr Genet 2018; 64:1173-1176. [PMID: 29644456 DOI: 10.1007/s00294-018-0835-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 04/04/2018] [Accepted: 04/06/2018] [Indexed: 01/18/2023]
Abstract
Proper cell function depends on networks of proteins that interact physically and functionally to carry out physiological processes. Thus, it seems logical that the impact of sequence variation in one protein could be significantly influenced by genetic variants at other loci in a genome. Nonetheless, the importance of such genetic interactions, known as epistasis, in explaining phenotypic variation remains a matter of debate in genetics. Recent work from our lab revealed that genes implicated from an association study of toxin tolerance in Saccharomyces cerevisiae show extensive interactions with the genetic background: most implicated genes, regardless of allele, are important for toxin tolerance in only one of two tested strains. The prevalence of background effects in our study adds to other reports of widespread genetic-background interactions in model organisms. We suggest that these effects represent many-way interactions with myriad features of the cellular system that vary across classes of individuals. Such gene-by-system interactions may influence diverse traits and require new modeling approaches to accurately represent genotype-phenotype relationships across individuals.
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Affiliation(s)
- Maria Sardi
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Cargill, Incorporated, Minneapolis, MN, 55440, USA
| | - Audrey P Gasch
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53706, USA.
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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28
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Whole-Genome Sequencing of Suppressor DNA Mixtures Identifies Pathways That Compensate for Chromosome Segregation Defects in Schizosaccharomyces pombe. G3-GENES GENOMES GENETICS 2018; 8:1031-1038. [PMID: 29352077 PMCID: PMC5844291 DOI: 10.1534/g3.118.200048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Suppressor screening is a powerful method to identify genes that, when mutated, rescue the temperature sensitivity of the original mutation. Previously, however, identification of suppressor mutations has been technically difficult. Due to the small genome size of Schizosaccharomyces pombe, we developed a spontaneous suppressor screening technique, followed by a cost-effective sequencing method. Genomic DNAs of 10 revertants that survived at the restrictive temperature of the original temperature sensitive (ts) mutant were mixed together as one sample before constructing a library for sequencing. Responsible suppressor mutations were identified bioinformatically based on allele frequency. Then, we isolated a large number of spontaneous extragenic suppressors for three ts mutants that exhibited defects in chromosome segregation at their restrictive temperature. Screening provided new insight into mechanisms of chromosome segregation: loss of Ufd2 E4 multi-ubiquitination activity suppresses defects of an AAA ATPase, Cdc48. Loss of Wpl1, a releaser of cohesin, compensates for the Eso1 mutation, which may destabilize sister chromatid cohesion. The segregation defect of a ts histone H2B mutant is rescued if it fails to be deubiquitinated by the SAGA complex, because H2B is stabilized by monoubiquitination.
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29
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Roguev A, Ryan CJ, Hartsuiker E, Krogan NJ. High-Throughput Quantitative Genetic Interaction Mapping in the Fission Yeast Schizosaccharomyces pombe. Cold Spring Harb Protoc 2018; 2018:pdb.top079905. [PMID: 28733404 DOI: 10.1101/pdb.top079905] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Epistasis mapping, in which the phenotype that emerges from combining pairs of mutations is measured quantitatively, is a powerful tool for unbiased study of gene function. When performed at a large scale, this approach has been used to assign function to previously uncharacterized genes, define functional modules and pathways, and study their cross talk. These experiments rely heavily on methods for rapid sampling of binary combinations of mutant alleles by systematic generation of a series of double mutants. Epistasis mapping technologies now exist in various model systems. Here we provide an overview of different epistasis mapping technologies, including the pombe epistasis mapper (PEM) system designed for the collection of quantitative genetic interaction data in fission yeast Schizosaccharomyces pombe Comprising a series of high-throughput selection steps for generation and characterization of double mutants, the PEM system has provided insight into a wide range of biological processes as well as facilitated evolutionary analysis of genetic interactomes across different species.
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Affiliation(s)
- Assen Roguev
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California 94518
| | - Colm J Ryan
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland
| | - Edgar Hartsuiker
- North West Cancer Research Institute, Bangor University, Bangor LL57 2UW, United Kingdom
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California 94518
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30
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Colson I, Hartsuiker E. Genetic Interaction Screens in Schizosaccharomyces pombe Using the Pombe Epistasis Mapper (PEM) System and a Manual Colony Replicator. Cold Spring Harb Protoc 2018; 2018:pdb.prot091967. [PMID: 28733416 DOI: 10.1101/pdb.prot091967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In laboratories in which a colony-replicating robot is not available, manual replication provides a good, low-cost alternative for genetic interaction screening using the Pombe Epistasis Mapper (PEM) system. The protocol presented here describes the minimum number of steps required to identify genetic interactions. First, a query deletion is introduced to a library of deletion mutants by mating. Through a series of subsequent selection steps, single and double mutants are isolated and analyzed.
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Affiliation(s)
- Isabelle Colson
- North West Cancer Research Institute, Bangor University, Bangor LL57 2UW, United Kingdom
| | - Edgar Hartsuiker
- North West Cancer Research Institute, Bangor University, Bangor LL57 2UW, United Kingdom
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31
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Roguev A, Xu J, Krogan N. Genetic Interaction Mapping in Schizosaccharomyces pombe Using the Pombe Epistasis Mapper (PEM) System and a ROTOR HDA Colony Replicating Robot in a 1536 Array Format. Cold Spring Harb Protoc 2018; 2018:pdb.prot091975. [PMID: 28733394 DOI: 10.1101/pdb.prot091975] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This protocol describes an optimized high-throughput procedure for generating double deletion mutants in Schizosaccharomyces pombe using the colony replicating robot ROTOR HDA and the PEM (pombe epistasis mapper) system. The method is based on generating high-density colony arrays (1536 colonies per agar plate) and passaging them through a series of antidiploid and mating-type selection (ADS-MTS) and double-mutant selection (DMS) steps. Detailed program parameters for each individual replication step are provided. Using this procedure, batches of 25 or more screens can be routinely performed.
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Affiliation(s)
- Assen Roguev
- Department Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California 94518
| | - Jiewei Xu
- Department Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California 94518
| | - Nevan Krogan
- Department Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California 94518
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32
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Barton DBH, Georghiou D, Dave N, Alghamdi M, Walsh TA, Louis EJ, Foster SS. PHENOS: a high-throughput and flexible tool for microorganism growth phenotyping on solid media. BMC Microbiol 2018; 18:9. [PMID: 29368646 PMCID: PMC5784713 DOI: 10.1186/s12866-017-1143-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/18/2017] [Indexed: 01/01/2023] Open
Abstract
Background Microbial arrays, with a large number of different strains on a single plate printed with robotic precision, underpin an increasing number of genetic and genomic approaches. These include Synthetic Genetic Array analysis, high-throughput Quantitative Trait Loci (QTL) analysis and 2-hybrid techniques. Measuring the growth of individual colonies within these arrays is an essential part of many of these techniques but is useful for any work with arrays. Measurement is typically done using intermittent imagery fed into complex image analysis software, which is not especially accurate and is challenging to use effectively. We have developed a simple and fast alternative technique that uses a pinning robot and a commonplace microplate reader to continuously measure the thickness of colonies growing on solid agar, complemented by a technique for normalizing the amount of cells initially printed to each spot of the array in the first place. We have developed software to automate the process of combining multiple sets of readings, subtracting agar absorbance, and visualizing colony thickness changes in a number of informative ways. Results The “PHENOS” pipeline (PHENotyping On Solid media), optimized for Saccharomyces yeasts, produces highly reproducible growth curves and is particularly sensitive to low-level growth. We have empirically determined a formula to estimate colony cell count from an absorbance measurement, and shown this to be comparable with estimates from measurements in liquid. We have also validated the technique by reproducing the results of an earlier QTL study done with conventional liquid phenotyping, and found PHENOS to be considerably more sensitive. Conclusions “PHENOS” is a cost effective and reliable high-throughput technique for quantifying growth of yeast arrays, and is likely to be equally very useful for a range of other types of microbial arrays. A detailed guide to the pipeline and software is provided with the installation files at https://github.com/gact/phenos. Electronic supplementary material The online version of this article (10.1186/s12866-017-1143-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- David B H Barton
- Department of Genetics & Genome Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Danae Georghiou
- Department of Genetics & Genome Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Neelam Dave
- Department of Genetics & Genome Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Majed Alghamdi
- Department of Genetics & Genome Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Thomas A Walsh
- Department of Genetics & Genome Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Edward J Louis
- Department of Genetics & Genome Biology, University of Leicester, Leicester, LE1 7RH, UK.
| | - Steven S Foster
- Department of Genetics & Genome Biology, University of Leicester, Leicester, LE1 7RH, UK.
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Simms CL, Yan LL, Zaher HS. Ribosome Collision Is Critical for Quality Control during No-Go Decay. Mol Cell 2017; 68:361-373.e5. [PMID: 28943311 DOI: 10.1016/j.molcel.2017.08.019] [Citation(s) in RCA: 186] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 05/08/2017] [Accepted: 08/21/2017] [Indexed: 10/18/2022]
Abstract
No-go decay (NGD) is a eukaryotic quality control mechanism that evolved to cope with translational arrests. The process is characterized by an endonucleolytic cleavage near the stall sequence, but the mechanistic details are unclear. Our analysis of cleavage sites indicates that cleavage requires multiple ribosomes on the mRNA. We also show that reporters harboring stall sequences near the initiation codon, which cannot accommodate multiple ribosomes, are not subject to NGD. Consistent with our model, we uncover an inverse correlation between ribosome density per mRNA and cleavage efficiency. Furthermore, promoting global ribosome collision in vivo resulted in ubiquitination of ribosomal proteins, suggesting that collision is sensed by the cell to initiate downstream quality control processes. Collectively, our data suggest that NGD and subsequent quality control are triggered by ribosome collision. This model provides insight into the regulation of quality control processes and the manner by which they reduce off-target effects.
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Affiliation(s)
- Carrie L Simms
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Liewei L Yan
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Hani S Zaher
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
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Abstract
In this introduction we discuss some basic genetic tools and techniques that are used with the fission yeast Schizosaccharomyces pombe Genes commonly used for selection or as reporters are discussed, with an emphasis on genes that permit counterselection, intragenic complementation, or colony-color assays. S. pombe is most stable as a haploid organism. We describe its mating-type system, how to perform genetic crosses and methods for selecting and propagating diploids. We discuss the relative merits of tetrad dissection and random spore preparation in strain construction and genetic analyses. Finally, we present several types of mutant screens, with an evaluation of their respective strengths and limitations in the light of emerging technologies such as next-generation sequencing.
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Affiliation(s)
- Karl Ekwall
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm SE-141 83, Sweden;
| | - Geneviève Thon
- Department of Biology, University of Copenhagen, Copenhagen DK-2200, Denmark
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35
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Rodríguez-López M, Cotobal C, Fernández-Sánchez O, Borbarán Bravo N, Oktriani R, Abendroth H, Uka D, Hoti M, Wang J, Zaratiegui M, Bähler J. A CRISPR/Cas9-based method and primer design tool for seamless genome editing in fission yeast. Wellcome Open Res 2017; 1:19. [PMID: 28612052 PMCID: PMC5445975 DOI: 10.12688/wellcomeopenres.10038.3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2017] [Indexed: 01/24/2023] Open
Abstract
In the fission yeast
Schizosaccharomyces pombe the prevailing approach for gene manipulations is based on homologous recombination of a PCR product that contains genomic target sequences and a selectable marker. The CRISPR/Cas9 system has recently been implemented in fission yeast, which allows for seamless genome editing without integration of a selection marker or leaving any other genomic ‘scars’. The published method involves manual design of the single guide RNA (sgRNA), and digestion of a large plasmid with a problematic restriction enzyme to clone the sgRNA. To increase the efficiency of this approach, we have established and optimized a PCR-based system to clone the sgRNA without restriction enzymes into a plasmid with a dominant
natMX6 (nourseothricin)
selection marker. We also provide a web-tool, CRISPR4P, to support the design of the sgRNAs and the primers required for the entire process of seamless DNA deletion. Moreover, we report the preparation of G1-synchronized and cryopreserved
S. pombe cells, which greatly increases the efficiency and speed for transformations, and may also facilitate standard gene manipulations. Applying this optimized CRISPR/Cas9-based approach, we have successfully deleted over 80 different non-coding RNA genes, which are generally lowly expressed, and have inserted 7 point mutations in 4 different genomic regions.
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Affiliation(s)
- María Rodríguez-López
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Cristina Cotobal
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Oscar Fernández-Sánchez
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Natalia Borbarán Bravo
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Risky Oktriani
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Heike Abendroth
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Dardan Uka
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Mimoza Hoti
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Jin Wang
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Mikel Zaratiegui
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, USA
| | - Jürg Bähler
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
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36
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Rodríguez-López M, Cotobal C, Fernández-Sánchez O, Borbarán Bravo N, Oktriani R, Abendroth H, Uka D, Hoti M, Wang J, Zaratiegui M, Bähler J. A CRISPR/Cas9-based method and primer design tool for seamless genome editing in fission yeast. Wellcome Open Res 2017. [PMID: 28612052 DOI: 10.12688/wellcomeopenres.10038.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In the fission yeast Schizosaccharomyces pombe the prevailing approach for gene manipulations is based on homologous recombination of a PCR product that contains genomic target sequences and a selectable marker. The CRISPR/Cas9 system has recently been implemented in fission yeast, which allows for seamless genome editing without integration of a selection marker or leaving any other genomic 'scars'. The published method involves manual design of the single guide RNA (sgRNA), and digestion of a large plasmid with a problematic restriction enzyme to clone the sgRNA. To increase the efficiency of this approach, we have established and optimized a PCR-based system to clone the sgRNA without restriction enzymes into a plasmid with a dominant natMX6 (nourseothricin) selection marker. We also provide a web-tool, CRISPR4P, to support the design of the sgRNAs and the primers required for the entire process of seamless DNA deletion. Moreover, we report the preparation of G1-synchronized and cryopreserved S. pombe cells, which greatly increases the efficiency and speed for transformations, and may also facilitate standard gene manipulations. Applying this optimized CRISPR/Cas9-based approach, we have successfully deleted over 80 different non-coding RNA genes, which are generally lowly expressed, and have inserted 7 point mutations in 4 different genomic regions.
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Affiliation(s)
- María Rodríguez-López
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Cristina Cotobal
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Oscar Fernández-Sánchez
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Natalia Borbarán Bravo
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Risky Oktriani
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Heike Abendroth
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Dardan Uka
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Mimoza Hoti
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Jin Wang
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Mikel Zaratiegui
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, USA
| | - Jürg Bähler
- Research Department of Genetics, Evolution and Environment, University College London, London, UK
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Wong A. Epistasis and the Evolution of Antimicrobial Resistance. Front Microbiol 2017; 8:246. [PMID: 28261193 PMCID: PMC5313483 DOI: 10.3389/fmicb.2017.00246] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/06/2017] [Indexed: 01/08/2023] Open
Abstract
The fitness effects of a mutation can depend, sometimes dramatically, on genetic background; this phenomenon is often referred to as “epistasis.” Epistasis can have important practical consequences in the context of antimicrobial resistance (AMR). For example, genetic background plays an important role in determining the costs of resistance, and hence in whether resistance will persist in the absence of antibiotic pressure. Furthermore, interactions between resistance mutations can have important implications for the evolution of multi-drug resistance. I argue that there is a need to better characterize the extent and nature of epistasis for mutations and horizontally transferred elements conferring AMR, particularly in clinical contexts. Furthermore, I suggest that epistasis should be an important consideration in attempts to slow or limit the evolution of AMR.
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Affiliation(s)
- Alex Wong
- Department of Biology, Carleton University, Ottawa ON, Canada
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38
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Koo BM, Kritikos G, Farelli JD, Todor H, Tong K, Kimsey H, Wapinski I, Galardini M, Cabal A, Peters JM, Hachmann AB, Rudner DZ, Allen KN, Typas A, Gross CA. Construction and Analysis of Two Genome-Scale Deletion Libraries for Bacillus subtilis. Cell Syst 2017; 4:291-305.e7. [PMID: 28189581 DOI: 10.1016/j.cels.2016.12.013] [Citation(s) in RCA: 348] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 11/19/2016] [Accepted: 12/21/2016] [Indexed: 12/16/2022]
Abstract
A systems-level understanding of Gram-positive bacteria is important from both an environmental and health perspective and is most easily obtained when high-quality, validated genomic resources are available. To this end, we constructed two ordered, barcoded, erythromycin-resistance- and kanamycin-resistance-marked single-gene deletion libraries of the Gram-positive model organism, Bacillus subtilis. The libraries comprise 3,968 and 3,970 genes, respectively, and overlap in all but four genes. Using these libraries, we update the set of essential genes known for this organism, provide a comprehensive compendium of B. subtilis auxotrophic genes, and identify genes required for utilizing specific carbon and nitrogen sources, as well as those required for growth at low temperature. We report the identification of enzymes catalyzing several missing steps in amino acid biosynthesis. Finally, we describe a suite of high-throughput phenotyping methodologies and apply them to provide a genome-wide analysis of competence and sporulation. Altogether, we provide versatile resources for studying gene function and pathway and network architecture in Gram-positive bacteria.
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Affiliation(s)
- Byoung-Mo Koo
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - George Kritikos
- European Molecular Biology Laboratory, Genome Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | | | - Horia Todor
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kenneth Tong
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Harvey Kimsey
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ilan Wapinski
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Marco Galardini
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Angelo Cabal
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jason M Peters
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Anna-Barbara Hachmann
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - David Z Rudner
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Karen N Allen
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Athanasios Typas
- European Molecular Biology Laboratory, Genome Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
| | - Carol A Gross
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute of Quantitative Biology, University of California, San Francisco, San Francisco, CA 94158, USA.
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Haliburton JR, Shao W, Deutschbauer A, Arkin A, Abate AR. Genetic interaction mapping with microfluidic-based single cell sequencing. PLoS One 2017; 12:e0171302. [PMID: 28170417 PMCID: PMC5295688 DOI: 10.1371/journal.pone.0171302] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 01/19/2017] [Indexed: 11/30/2022] Open
Abstract
Genetic interaction mapping is useful for understanding the molecular basis of cellular decision making, but elucidating interactions genome-wide is challenging due to the massive number of gene combinations that must be tested. Here, we demonstrate a simple approach to thoroughly map genetic interactions in bacteria using microfluidic-based single cell sequencing. Using single cell PCR in droplets, we link distinct genetic information into single DNA sequences that can be decoded by next generation sequencing. Our approach is scalable and theoretically enables the pooling of entire interaction libraries to interrogate multiple pairwise genetic interactions in a single culture. The speed, ease, and low-cost of our approach makes genetic interaction mapping viable for routine characterization, allowing the interaction network to be used as a universal read out for a variety of biology experiments, and for the elucidation of interaction networks in non-model organisms.
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Affiliation(s)
- John R. Haliburton
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California, United States of America
| | - Wenjun Shao
- Department of Bioengineering, University of California Berkeley, Berkeley, California, United States of America
| | - Adam Deutschbauer
- Department of Bioengineering, University of California Berkeley, Berkeley, California, United States of America
- E.O. Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Adam Arkin
- Department of Bioengineering, University of California Berkeley, Berkeley, California, United States of America
- E.O. Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Adam R. Abate
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California, United States of America
- * E-mail:
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Rodríguez-López M, Cotobal C, Fernández-Sánchez O, Borbarán Bravo N, Oktriani R, Abendroth H, Uka D, Hoti M, Wang J, Zaratiegui M, Bähler J. A CRISPR/Cas9-based method and primer design tool for seamless genome editing in fission yeast. Wellcome Open Res 2017. [DOI: 10.12688/wellcomeopenres.10038.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the fission yeast Schizosaccharomyces pombe the prevailing approach for gene manipulations is based on homologous recombination of a PCR product that contains genomic target sequences and a selectable marker. The CRISPR/Cas9 system has recently been implemented in fission yeast, which allows for seamless genome editing without integration of a selection marker or leaving any other genomic ‘scars’. The published method involves manual design of the single guide RNA (sgRNA), and digestion of a large plasmid with a problematic restriction enzyme to clone the sgRNA. To increase the efficiency of this approach, we have established and optimized a PCR-based system to clone the sgRNA without restriction enzymes into a plasmid with a dominant natMX6 (nourseothricin) selection marker. We also provide a web-tool, CRISPR4P, to support the design of the sgRNAs and the primers required for the entire process of seamless DNA deletion. Moreover, we report the preparation of G1-synchronized and cryopreserved S. pombe cells, which greatly increases the efficiency and speed for transformations, and may also facilitate standard gene manipulations. Applying this optimized CRISPR/Cas9-based approach, we have successfully deleted over 80 different non-coding RNA genes, which are generally lowly expressed, and have inserted 7 point mutations in 4 different genomic regions.
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41
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Spotsizer: High-throughput quantitative analysis of microbial growth. Biotechniques 2016; 61:191-201. [PMID: 27712582 DOI: 10.2144/000114459] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 10/02/2016] [Indexed: 12/31/2022] Open
Abstract
Microbial colony growth can serve as a useful readout in assays for studying complex genetic interactions or the effects of chemical compounds. Although computational tools for acquiring quantitative measurements of microbial colonies have been developed, their utility can be compromised by inflexible input image requirements, non-trivial installation procedures, or complicated operation. Here, we present the Spotsizer software tool for automated colony size measurements in images of robotically arrayed microbial colonies. Spotsizer features a convenient graphical user interface (GUI), has both single-image and batch-processing capabilities, and works with multiple input image formats and different colony grid types. We demonstrate how Spotsizer can be used for high-throughput quantitative analysis of fission yeast growth. The user-friendly Spotsizer tool provides rapid, accurate, and robust quantitative analyses of microbial growth in a high-throughput format. Spotsizer is freely available at https://data.csiro.au/dap/landingpage?pid=csiro:15330 under a proprietary CSIRO license.
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42
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Coorey NVC, Matthews JH, Bellows DS, Atkinson PH. Pleiotropic drug-resistance attenuated genomic library improves elucidation of drug mechanisms. MOLECULAR BIOSYSTEMS 2016; 11:3129-36. [PMID: 26381459 DOI: 10.1039/c5mb00406c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Identifying Saccharomyces cerevisiae genome-wide gene deletion mutants that confer hypersensitivity to a xenobiotic aids the elucidation of its mechanism of action (MoA). However, the biological activities of many xenobiotics are masked by the pleiotropic drug resistance (PDR) network which effluxes xenobiotics that are PDR substrates. The PDR network in S. cerevisiae is almost entirely under the control of two functionally homologous transcription factors Pdr1p and Pdr3p. Herein we report the construction of a PDR-attenuated haploid non-essential DMA (PA-DMA), lacking PDR1 and PDR3, which permits the MoA elucidation of xenobiotics that are PDR substrates at low concentrations. The functionality of four key cellular processes commonly activated in response to xenobiotic stress: oxidative stress response, general stress response, unfolded stress response and calcium signalling pathways were assessed in the absence of PDR1 and PDR3 genes and were found to unaltered, therefore, these key chemogenomic signatures are not lost when using the PA-DMA. Efficacy of the PA-DMA was demonstrated using cycloheximide and latrunculin A at low nanomolar concentrations to attain chemical genetic profiles that were more specific to their known main mechanisms. We also found a two-fold increase in the number of compounds that are bioactive in the pdr1Δpdr3Δ compared to the wild type strain in screening the commercially available LOPAC(1280) library. The PA-DMA should be particularly applicable to mechanism determination of xenobiotics that have limited availability, such as natural products.
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Affiliation(s)
- Namal V C Coorey
- Centre for Biodiscovery, School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Kelburn, Wellington, 6011, New Zealand.
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Srivas R, Shen JP, Yang CC, Sun SM, Li J, Gross AM, Jensen J, Licon K, Bojorquez-Gomez A, Klepper K, Huang J, Pekin D, Xu JL, Yeerna H, Sivaganesh V, Kollenstart L, van Attikum H, Aza-Blanc P, Sobol RW, Ideker T. A Network of Conserved Synthetic Lethal Interactions for Exploration of Precision Cancer Therapy. Mol Cell 2016; 63:514-25. [PMID: 27453043 DOI: 10.1016/j.molcel.2016.06.022] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 03/03/2016] [Accepted: 06/15/2016] [Indexed: 01/06/2023]
Abstract
An emerging therapeutic strategy for cancer is to induce selective lethality in a tumor by exploiting interactions between its driving mutations and specific drug targets. Here we use a multi-species approach to develop a resource of synthetic lethal interactions relevant to cancer therapy. First, we screen in yeast ∼169,000 potential interactions among orthologs of human tumor suppressor genes (TSG) and genes encoding drug targets across multiple genotoxic environments. Guided by the strongest signal, we evaluate thousands of TSG-drug combinations in HeLa cells, resulting in networks of conserved synthetic lethal interactions. Analysis of these networks reveals that interaction stability across environments and shared gene function increase the likelihood of observing an interaction in human cancer cells. Using these rules, we prioritize ∼10(5) human TSG-drug combinations for future follow-up. We validate interactions based on cell and/or patient survival, including topoisomerases with RAD17 and checkpoint kinases with BLM.
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Affiliation(s)
- Rohith Srivas
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA; The Cancer Cell Map Initiative
| | - John Paul Shen
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA; The Cancer Cell Map Initiative
| | - Chih Cheng Yang
- Functional Genomics Core, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Su Ming Sun
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Jianfeng Li
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA
| | - Andrew M Gross
- Bioinformatics and Systems Biology Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - James Jensen
- Bioinformatics and Systems Biology Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Katherine Licon
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Ana Bojorquez-Gomez
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Kristin Klepper
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Justin Huang
- Bioinformatics and Systems Biology Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel Pekin
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Jia L Xu
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Huwate Yeerna
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Vignesh Sivaganesh
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Leonie Kollenstart
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Pedro Aza-Blanc
- Functional Genomics Core, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Robert W Sobol
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA
| | - Trey Ideker
- Division of Genetics, Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA; The Cancer Cell Map Initiative.
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44
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Murray JM, Watson AT, Carr AM. Molecular Genetic Tools and Techniques in Fission Yeast. Cold Spring Harb Protoc 2016; 2016:2016/5/pdb.top087601. [PMID: 27140925 DOI: 10.1101/pdb.top087601] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The molecular genetic tools used in fission yeast have generally been adapted from methods and approaches developed for use in the budding yeast, Saccharomyces cerevisiae Initially, the molecular genetics of Schizosaccharomyces pombe was developed to aid gene identification, but it is now applied extensively to the analysis of gene function and the manipulation of noncoding sequences that affect chromosome dynamics. Much current research using fission yeast thus relies on the basic processes of introducing DNA into the organism and the extraction of DNA for subsequent analysis. Targeted integration into specific genomic loci is often used to create site-specific mutants or changes to noncoding regulatory elements for subsequent phenotypic analysis. It is also regularly used to introduce additional sequences that generate tagged proteins or to create strains in which the levels of wild-type protein can be manipulated through transcriptional regulation and/or protein degradation. Here, we draw together a collection of core molecular genetic techniques that underpin much of modern research using S. pombe We summarize the most useful methods that are routinely used and provide guidance, learned from experience, for the successful application of these methods.
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Affiliation(s)
- Johanne M Murray
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, E. Sussex BN1 9RQ, United Kingdom
| | - Adam T Watson
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, E. Sussex BN1 9RQ, United Kingdom
| | - Antony M Carr
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, E. Sussex BN1 9RQ, United Kingdom
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45
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Jin SH, Jang SC, Lee B, Jeong HH, Jeong SG, Lee SS, Kim KP, Lee CS. Monitoring of chromosome dynamics of single yeast cells in a microfluidic platform with aperture cell traps. LAB ON A CHIP 2016; 16:1358-1365. [PMID: 26980179 DOI: 10.1039/c5lc01422k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Chromosome movement plays important roles in DNA replication, repair, genetic recombination, and epigenetic phenomena during mitosis and meiosis. In particular, chromosome movement in the nuclear space is essential for the reorganization of the nucleus. However, conventional methods for analyzing the chromosome movements in vivo have been limited by technical constraints of cell trapping, cell cultivation, oxygenation, and in situ imaging. Here, we present a simple microfluidic platform with aperture-based cell trapping arrays to monitor the chromosome dynamics in single living cells for a desired period of time. Under the optimized conditions, our microfluidic platform shows a single-cell trapping efficiency of 57%. This microfluidic approach enables in situ imaging of intracellular dynamics in living cells responding to variable input stimuli under the well-controlled microenvironment. As a validation of this microfluidic platform, we investigate the fundamental features of the dynamic cellular response of the individual cells treated with different stimuli and drug. We prove the basis for dynamic chromosome movement in single yeast cells to be the telomere and nuclear envelope ensembles that attach to and move in concert with nuclear actin cables. Therefore, these results illustrate the monitoring of cellular functions and obtaining of dynamic information at a high spatiotemporal resolution through the integration of a simple microfluidic platform.
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Affiliation(s)
- Si Hyung Jin
- Department of Chemical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
| | - Sung-Chan Jang
- Department of Chemical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
| | - Byungjin Lee
- Department of Chemical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
| | - Heon-Ho Jeong
- Department of Chemical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
| | - Seong-Geun Jeong
- Department of Chemical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
| | - Sung Sik Lee
- Institute of Biochemistry, ETH Zürich, Zürich, CH 8093, Switzerland. leesu@ ethz.ch and Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zürich, Zürich, CH-8093, Switzerland
| | - Keun Pil Kim
- Department of Life Science, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Chang-Soo Lee
- Department of Chemical Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-Gu, Daejeon 305-764, Republic of Korea.
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Pluskal T, Sajiki K, Becker J, Takeda K, Yanagida M. Diverse fission yeast genes required for responding to oxidative and metal stress: Comparative analysis of glutathione-related and other defense gene deletions. Genes Cells 2016; 21:530-42. [PMID: 27005325 DOI: 10.1111/gtc.12359] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 02/22/2016] [Indexed: 12/25/2022]
Abstract
Living organisms have evolved multiple sophisticated mechanisms to deal with reactive oxygen species. We constructed a collection of twelve single-gene deletion strains of the fission yeast Schizosaccharomyces pombe designed for the study of oxidative and heavy metal stress responses. This collection contains deletions of biosynthetic enzymes of glutathione (Δgcs1 and Δgsa1), phytochelatin (Δpcs2), ubiquinone (Δabc1) and ergothioneine (Δegt1), as well as catalase (Δctt1), thioredoxins (Δtrx1 and Δtrx2), Cu/Zn- and Mn- superoxide dismutases (SODs; Δsod1 and Δsod2), sulfiredoxin (Δsrx1) and sulfide-quinone oxidoreductase (Δhmt2). First, we employed metabolomic analysis to examine the mutants of the glutathione biosynthetic pathway. We found that ophthalmic acid was produced by the same enzymes as glutathione in S. pombe. The identical genetic background of the strains allowed us to assess the severity of the individual gene knockouts by treating the deletion strains with oxidative agents. Among other results, we found that glutathione deletion strains were not particularly sensitive to peroxide or superoxide, but highly sensitive to cadmium stress. Our results show the astonishing diversity in cellular adaptation mechanisms to various types of oxidative and metal stress and provide a useful tool for further research into stress responses.
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Affiliation(s)
- Tomáš Pluskal
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna, Okinawa, Japan
| | - Kenichi Sajiki
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna, Okinawa, Japan
| | - Joanne Becker
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna, Okinawa, Japan
| | - Kojiro Takeda
- Department of Biology, Faculty of Science and Engineering and Institute for Integrative Neurobiology, Konan University, Kobe, Hyogo, Japan
| | - Mitsuhiro Yanagida
- G0 Cell Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna, Okinawa, Japan
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Kakui Y, Sunaga T, Arai K, Dodgson J, Ji L, Csikász-Nagy A, Carazo-Salas R, Sato M. Module-based construction of plasmids for chromosomal integration of the fission yeast Schizosaccharomyces pombe. Open Biol 2016; 5:150054. [PMID: 26108218 PMCID: PMC4632507 DOI: 10.1098/rsob.150054] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Integration of an external gene into a fission yeast chromosome is useful to investigate the effect of the gene product. An easy way to knock-in a gene construct is use of an integration plasmid, which can be targeted and inserted to a chromosome through homologous recombination. Despite the advantage of integration, construction of integration plasmids is energy- and time-consuming, because there is no systematic library of integration plasmids with various promoters, fluorescent protein tags, terminators and selection markers; therefore, researchers are often forced to make appropriate ones through multiple rounds of cloning procedures. Here, we establish materials and methods to easily construct integration plasmids. We introduce a convenient cloning system based on Golden Gate DNA shuffling, which enables the connection of multiple DNA fragments at once: any kind of promoters and terminators, the gene of interest, in combination with any fluorescent protein tag genes and any selection markers. Each of those DNA fragments, called a ‘module’, can be tandemly ligated in the order we desire in a single reaction, which yields a circular plasmid in a one-step manner. The resulting plasmids can be integrated through standard methods for transformation. Thus, these materials and methods help easy construction of knock-in strains, and this will further increase the value of fission yeast as a model organism.
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Affiliation(s)
- Yasutaka Kakui
- Chromosome Segregation Laboratory, The Francis Crick Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Tomonari Sunaga
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University TWIns, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-0056, Japan
| | - Kunio Arai
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University TWIns, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-0056, Japan Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
| | - James Dodgson
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Liang Ji
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University TWIns, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-0056, Japan Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
| | - Attila Csikász-Nagy
- Department of Computational Biology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige 38010, Italy Randall Division of Cell and Molecular Biophysics and Institute for Mathematical and Molecular Biomedicine, King's College London, London SE1 1UL, UK
| | - Rafael Carazo-Salas
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Masamitsu Sato
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University TWIns, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-0056, Japan Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
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48
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Gaspa L, González-Medina A, Hidalgo E, Ayté J. A functional genome-wide genetic screening identifies new pathways controlling the G1/S transcriptional wave. Cell Cycle 2016; 15:720-9. [PMID: 26890608 DOI: 10.1080/15384101.2016.1148839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
The Schizosaccharomyces pombe MBF complex activates the transcription of genes required for DNA synthesis and S phase. The MBF complex contains several proteins, including the core components Cdc10, Res1 and Res2, the co-repressor proteins Yox1 and Nrm1 and the co-activator Rep2. It has recently been shown how MBF is regulated when either the DNA damage or the DNA synthesis checkpoints are activated. However, how MBF is regulated in a normal unperturbed cell cycle is still not well understood. We have set up a genome-wide genomic screen searching for global regulators of MBF. We have crossed our knock-out collection library with a reporter strain that allows the measurement of MBF activity in live cells by flow cytometry. We confirm previously known regulators of MBF and show that COP9/signalosome and tRNA methyltransferases also regulate MBF activity.
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Affiliation(s)
- Laura Gaspa
- a Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra , Barcelona , Spain
| | | | - Elena Hidalgo
- a Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra , Barcelona , Spain
| | - José Ayté
- a Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra , Barcelona , Spain
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Verrier L, Taglini F, Barrales RR, Webb S, Urano T, Braun S, Bayne EH. Global regulation of heterochromatin spreading by Leo1. Open Biol 2016; 5:rsob.150045. [PMID: 25972440 PMCID: PMC4450266 DOI: 10.1098/rsob.150045] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Heterochromatin plays important roles in eukaryotic genome regulation. However, the repressive nature of heterochromatin combined with its propensity to self-propagate necessitates robust mechanisms to contain heterochromatin within defined boundaries and thus prevent silencing of expressed genes. Here we show that loss of the PAF complex (PAFc) component Leo1 compromises chromatin boundaries, resulting in invasion of heterochromatin into flanking euchromatin domains. Similar effects are seen upon deletion of other PAFc components, but not other factors with related functions in transcription-associated chromatin modification, indicating a specific role for PAFc in heterochromatin regulation. Loss of Leo1 results in reduced levels of H4K16 acetylation at boundary regions, while tethering of the H4K16 acetyltransferase Mst1 to boundary chromatin suppresses heterochromatin spreading in leo1Δ cells, suggesting that Leo1 antagonises heterochromatin spreading by promoting H4K16 acetylation. Our findings reveal a previously undescribed role for PAFc in regulating global heterochromatin distribution.
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Affiliation(s)
- Laure Verrier
- Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | | | - Ramon R Barrales
- Butenandt Institute of Physiological Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Shaun Webb
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Takeshi Urano
- Department of Biochemistry, Faculty of Medicine, Shimane University, Izumo, Japan
| | - Sigurd Braun
- Butenandt Institute of Physiological Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany
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García P, Encinar Del Dedo J, Ayté J, Hidalgo E. Genome-wide Screening of Regulators of Catalase Expression: ROLE OF A TRANSCRIPTION COMPLEX AND HISTONE AND tRNA MODIFICATION COMPLEXES ON ADAPTATION TO STRESS. J Biol Chem 2016; 291:790-9. [PMID: 26567340 DOI: 10.1074/jbc.m115.696658] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Indexed: 12/22/2022] Open
Abstract
In response to environmental cues, the mitogen-activated protein kinase Sty1-driven signaling cascade activates hundreds of genes to induce a robust anti-stress cellular response in fission yeast. Thus, upon stress imposition Sty1 transiently accumulates in the nucleus where it up-regulates transcription through the Atf1 transcription factor. Several regulators of transcription and translation have been identified as important to mount an integral response to oxidative stress, such as the Spt-Ada-Gcn5-acetyl transferase or Elongator complexes, respectively. With the aim of identifying new regulators of this massive gene expression program, we have used a GFP-based protein reporter and screened a fission yeast deletion collection using flow cytometry. We find that the levels of catalase fused to GFP, both before and after a threat of peroxides, are altered in hundreds of strains lacking components of chromatin modifiers, transcription complexes, and modulators of translation. Thus, the transcription elongation complex Paf1, the histone methylase Set1-COMPASS, and the translation-related Trm112 dimers are all involved in full expression of Ctt1-GFP and in wild-type tolerance to peroxides.
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Affiliation(s)
- Patricia García
- From the Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Javier Encinar Del Dedo
- From the Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain
| | - José Ayté
- From the Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Elena Hidalgo
- From the Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain
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