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Güleray Lafcı N, Karaosmanoglu B, Taskiran EZ, Simsek-Kiper PO, Utine GE. Mutated Transcripts of ZEB2 Do Not Undergo Nonsense-Mediated Decay in Mowat-Wilson Syndrome. Mol Syndromol 2023; 14:258-265. [PMID: 37323203 PMCID: PMC10267494 DOI: 10.1159/000528769] [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: 07/27/2021] [Accepted: 12/16/2022] [Indexed: 12/03/2023] Open
Abstract
Introduction Mowat-Wilson syndrome (MWS) is an autosomal-dominant complex developmental disorder characterized by distinctive facial appearance, intellectual disability, epilepsy, and various clinically heterogeneous abnormalities reminiscent of neurocristopathies. MWS is caused by haploinsufficiency of ZEB2 due to heterozygous point mutations and copy number variations. Case Presentation We report on two unrelated affected individuals with novel ZEB2indel mutations, molecularly confirming the diagnosis of MWS. Quantitative real-time polymerase chain reaction (PCR) for the comparison of total transcript levels and allele-specific quantitative real-time PCR were also performed and demonstrated that the truncating mutations did not lead to nonsense-mediated decay as expected. Conclusion ZEB2 encodes a multifunctional pleiotropic protein. Novel mutations in ZEB2 should be reported in order that genotype-phenotype correlations might be established in this clinically heterogeneous syndrome. Further cDNA and protein studies may help elucidate the underlying pathogenetic mechanisms of MWS since nonsense-mediated RNA decay was found to be absent in only a few studies including this study.
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Affiliation(s)
- Naz Güleray Lafcı
- Department of Medical Genetics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Beren Karaosmanoglu
- Department of Medical Genetics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Ekim Z. Taskiran
- Department of Medical Genetics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Pelin Ozlem Simsek-Kiper
- Department of Pediatric Genetics, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Gülen Eda Utine
- Department of Pediatric Genetics, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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2
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Engineering of Synthetic Transcriptional Switches in Yeast. Life (Basel) 2022; 12:life12040557. [PMID: 35455048 PMCID: PMC9030632 DOI: 10.3390/life12040557] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/31/2022] [Accepted: 04/03/2022] [Indexed: 02/04/2023] Open
Abstract
Transcriptional switches can be utilized for many purposes in synthetic biology, including the assembly of complex genetic circuits to achieve sophisticated cellular systems and the construction of biosensors for real-time monitoring of intracellular metabolite concentrations. Although to date such switches have mainly been developed in prokaryotes, those for eukaryotes are increasingly being reported as both rational and random engineering technologies mature. In this review, we describe yeast transcriptional switches with different modes of action and how to alter their properties. We also discuss directed evolution technologies for the rapid and robust construction of yeast transcriptional switches.
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3
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Ford KM, Panwala R, Chen DH, Portell A, Palmer N, Mali P. Peptide-tiling screens of cancer drivers reveal oncogenic protein domains and associated peptide inhibitors. Cell Syst 2021; 12:716-732.e7. [PMID: 34051140 PMCID: PMC8298269 DOI: 10.1016/j.cels.2021.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 02/09/2021] [Accepted: 03/30/2021] [Indexed: 02/07/2023]
Abstract
Gene fragments derived from structural domains mediating physical interactions can modulate biological functions. Utilizing this, we developed lentiviral overexpression libraries of peptides comprehensively tiling high-confidence cancer driver genes. Toward inhibiting cancer growth, we assayed ~66,000 peptides, tiling 65 cancer drivers and 579 mutant alleles. Pooled fitness screens in two breast cancer cell lines revealed peptides, which selectively reduced cellular proliferation, implicating oncogenic protein domains important for cell fitness. Coupling of cell-penetrating motifs to these peptides enabled drug-like function, with peptides derived from EGFR and RAF1 inhibiting cell growth at IC50s of 27-63 μM. We anticipate that this peptide-tiling (PepTile) approach will enable rapid de novo mapping of bioactive protein domains and associated interfering peptides.
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Affiliation(s)
- Kyle M Ford
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093, USA
| | - Rebecca Panwala
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093, USA
| | - Dai-Hua Chen
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093, USA
| | - Andrew Portell
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093, USA
| | - Nathan Palmer
- Division of Biological Sciences, University of California, San Diego, San Diego, CA 92093, USA
| | - Prashant Mali
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093, USA.
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4
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Knorre DA, Galkina KV, Shirokovskikh T, Banerjee A, Prasad R. Do Multiple Drug Resistance Transporters Interfere with Cell Functioning under Normal Conditions? BIOCHEMISTRY (MOSCOW) 2021; 85:1560-1569. [PMID: 33705294 DOI: 10.1134/s0006297920120081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Eukaryotic cells rely on multiple mechanisms to protect themselves from exogenous toxic compounds. For instance, cells can limit penetration of toxic molecules through the plasma membrane or sequester them within the specialized compartments. Plasma membrane transporters with broad substrate specificity confer multiple drug resistance (MDR) to cells. These transporters efflux toxic compounds at the cost of ATP hydrolysis (ABC-transporters) or proton influx (MFS-transporters). In our review, we discuss the possible costs of having an active drug-efflux system using yeast cells as an example. The pleiotropic drug resistance (PDR) subfamily ABC-transporters are known to constitutively hydrolyze ATP even without any substrate stimulation or transport across the membrane. Besides, some MDR-transporters have flippase activity allowing transport of lipids from inner to outer lipid layer of the plasma membrane. Thus, excessive activity of MDR-transporters can adversely affect plasma membrane properties. Moreover, broad substrate specificity of ABC-transporters also suggests the possibility of unintentional efflux of some natural metabolic intermediates from the cells. Furthermore, in some microorganisms, transport of quorum-sensing factors is mediated by MDR transporters; thus, overexpression of the transporters can also disturb cell-to-cell communications. As a result, under normal conditions, cells keep MDR-transporter genes repressed and activate them only upon exposure to stresses. We speculate that exploiting limitations of the drug-efflux system is a promising strategy to counteract MDR in pathogenic fungi.
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Affiliation(s)
- D A Knorre
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia. .,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, 119991, Russia
| | - K V Galkina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - T Shirokovskikh
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - A Banerjee
- Amity Institute of Biotechnology and Amity Institute of Integrative Sciences and Health, Amity University Haryana, Amity Education Valley, Gurugram, 122413, India
| | - R Prasad
- Amity Institute of Biotechnology and Amity Institute of Integrative Sciences and Health, Amity University Haryana, Amity Education Valley, Gurugram, 122413, India
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5
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Abrahams L, Hurst LD. A Depletion of Stop Codons in lincRNA is Owing to Transfer of Selective Constraint from Coding Sequences. Mol Biol Evol 2020; 37:1148-1164. [PMID: 31841162 PMCID: PMC7086181 DOI: 10.1093/molbev/msz299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although the constraints on a gene’s sequence are often assumed to reflect the functioning of that gene, here we propose transfer selection, a constraint operating on one class of genes transferred to another, mediated by shared binding factors. We show that such transfer can explain an otherwise paradoxical depletion of stop codons in long intergenic noncoding RNAs (lincRNAs). Serine/arginine-rich proteins direct the splicing machinery by binding exonic splice enhancers (ESEs) in immature mRNA. As coding exons cannot contain stop codons in one reading frame, stop codons should be rare within ESEs. We confirm that the stop codon density (SCD) in ESE motifs is low, even accounting for nucleotide biases. Given that serine/arginine-rich proteins binding ESEs also facilitate lincRNA splicing, a low SCD could transfer to lincRNAs. As predicted, multiexon lincRNA exons are depleted in stop codons, a result not explained by open reading frame (ORF) contamination. Consistent with transfer selection, stop codon depletion in lincRNAs is most acute in exonic regions with the highest ESE density, disappears when ESEs are masked, is consistent with stop codon usage skews in ESEs, and is diminished in both single-exon lincRNAs and introns. Owing to low SCD, the maximum lengths of pseudo-ORFs frequently exceed null expectations. This has implications for ORF annotation and the evolution of de novo protein-coding genes from lincRNAs. We conclude that not all constraints operating on genes need be explained by the functioning of the gene but may instead be transferred owing to shared binding factors.
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Affiliation(s)
- Liam Abrahams
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Laurence D Hurst
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
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6
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Dorrity MW, Queitsch C, Fields S. High-throughput identification of dominant negative polypeptides in yeast. Nat Methods 2019; 16:413-416. [PMID: 30962621 PMCID: PMC6555411 DOI: 10.1038/s41592-019-0368-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 03/01/2019] [Indexed: 12/25/2022]
Abstract
Dominant negative polypeptides can inhibit protein function by binding to a wild-type subunit or by titrating a ligand. Here we use high-throughput sequencing of libraries composed of fragments of yeast genes to identify polypeptides that act in a dominant negative manner, in that they are depleted during cell growth. The method can uncover numerous inhibitory polypeptides for a protein and thereby define small inhibitory regions, even pinpointing individual residues with critical functional roles.
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Affiliation(s)
- Michael W Dorrity
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Christine Queitsch
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Stanley Fields
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
- Department of Medicine, University of Washington, Seattle, WA, USA.
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7
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Huang Q, Zhong Q, Mayaka JBA, Ni J, Shen Y. Autophosphorylation and Cross-Phosphorylation of Protein Kinases from the Crenarchaeon Sulfolobus islandicus. Front Microbiol 2017; 8:2173. [PMID: 29163450 PMCID: PMC5682000 DOI: 10.3389/fmicb.2017.02173] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 10/23/2017] [Indexed: 11/17/2022] Open
Abstract
Protein phosphorylation, one of the most important post-translational modifications, regulates almost every cellular process. Although signal transduction by protein phosphorylation is extensively studied in Eukaryotes and Bacteria, the knowledge of this process in archaea is greatly lagging behind, especially for Ser/Thr/Tyr phosphorylation by eukaryotic-like protein kinases (ePKs). So far, only a few studies on archaeal ePKs have been reported, most of which focused on the phosphorylation activities in vitro, but their physiological functions and interacting network are still largely unknown. In this study, we systematically investigated the autophosphorylation and cross-phosphorylation activities of ePKs from Sulfolobus islandicus REY15A using proteins expressed in Escherichia coli or S. islandicus. In vitro kinase assay showed that 7 out of the 11 putative ePKs have autophosphorylation activity. A protein Ser/Thr phosphatase, SiRe_1009, was able to dephosphorylate various autophosphorylated ePKs, confirming that these proteins are Ser/Thr kinases. Two ePKs, SiRe_2030 and SiRe_2056, homologs of typical eukaryotic PKs involved in peptide synthesis in response to various cellular stresses, exhibit highly efficient phosphorylation activities on both themselves and other ePKs. Overexpression of the protein kinases in vivo revealed that elevated level of either SiRe_1531 or SiRe_2056 inhibited the cell growth of S. islandicus cells. Finally, a phosphorylation network of the protein kinases was proposed and their putative physiological roles were discussed.
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Affiliation(s)
- Qihong Huang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Qing Zhong
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Joseph B A Mayaka
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Jinfeng Ni
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Yulong Shen
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
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8
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Veitia RA, Govindaraju DR, Bottani S, Birchler JA. Aging: Somatic Mutations, Epigenetic Drift and Gene Dosage Imbalance. Trends Cell Biol 2017; 27:299-310. [DOI: 10.1016/j.tcb.2016.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 10/20/2022]
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9
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Abstract
Overexpression experiments are sometimes considered as qualitative experiments designed to identify novel proteins and study their function. However, in order to draw conclusions regarding protein overexpression through association analyses using large-scale biological data sets, we need to recognize the quantitative nature of overexpression experiments. Here I discuss the quantitative features of two different types of overexpression experiment: absolute and relative. I also introduce the four primary mechanisms involved in growth defects caused by protein overexpression: resource overload, stoichiometric imbalance, promiscuous interactions, and pathway modulation associated with the degree of overexpression.
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Affiliation(s)
- Hisao Moriya
- Research Core for Interdisciplinary Sciences, Okayama University, Okayama 700-8530, Japan
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10
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McLysaght A, Guerzoni D. New genes from non-coding sequence: the role of de novo protein-coding genes in eukaryotic evolutionary innovation. Philos Trans R Soc Lond B Biol Sci 2016; 370:20140332. [PMID: 26323763 PMCID: PMC4571571 DOI: 10.1098/rstb.2014.0332] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The origin of novel protein-coding genes de novo was once considered so improbable as to be impossible. In less than a decade, and especially in the last five years, this view has been overturned by extensive evidence from diverse eukaryotic lineages. There is now evidence that this mechanism has contributed a significant number of genes to genomes of organisms as diverse as Saccharomyces, Drosophila, Plasmodium, Arabidopisis and human. From simple beginnings, these genes have in some instances acquired complex structure, regulated expression and important functional roles. New genes are often thought of as dispensable late additions; however, some recent de novo genes in human can play a role in disease. Rather than an extremely rare occurrence, it is now evident that there is a relatively constant trickle of proto-genes released into the testing ground of natural selection. It is currently unknown whether de novo genes arise primarily through an ‘RNA-first’ or ‘ORF-first’ pathway. Either way, evolutionary tinkering with this pool of genetic potential may have been a significant player in the origins of lineage-specific traits and adaptations.
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Affiliation(s)
- Aoife McLysaght
- Smurfit Institute of Genetics, University of Dublin, Trinity College Dublin, Dublin 2, Republic of Ireland
| | - Daniele Guerzoni
- Smurfit Institute of Genetics, University of Dublin, Trinity College Dublin, Dublin 2, Republic of Ireland
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11
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Cuperus JT, Lo RS, Shumaker L, Proctor J, Fields S. A tetO Toolkit To Alter Expression of Genes in Saccharomyces cerevisiae. ACS Synth Biol 2015; 4:842-52. [PMID: 25742460 PMCID: PMC4506738 DOI: 10.1021/sb500363y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Strategies to optimize a metabolic pathway often involve building a large collection of strains, each containing different versions of sequences that regulate the expression of pathway genes. Here, we develop reagents and methods to carry out this process at high efficiency in the yeast Saccharomyces cerevisiae. We identify variants of the Escherichia coli tet operator (tetO) sequence that bind a TetR-VP16 activator with differential affinity and therefore result in different TetR-VP16 activator-driven expression. By recombining these variants upstream of the genes of a pathway, we generate unique combinations of expression levels. Here, we built a tetO toolkit, which includes the I-OnuI homing endonuclease to create double-strand breaks, which increases homologous recombination by 10(5); a plasmid carrying six variant tetO sequences flanked by I-OnuI sites, uncoupling transformation and recombination steps; an S. cerevisiae-optimized TetR-VP16 activator; and a vector to integrate constructs into the yeast genome. We introduce into the S. cerevisiae genome the three crt genes from Erwinia herbicola required for yeast to synthesize lycopene and carry out the recombination process to produce a population of cells with permutations of tetO variants regulating the three genes. We identify 0.7% of this population as making detectable lycopene, of which the vast majority have undergone recombination at all three crt genes. We estimate a rate of ∼20% recombination per targeted site, much higher than that obtained in other studies. Application of this toolkit to medically or industrially important end products could reduce the time and labor required to optimize the expression of a set of metabolic genes.
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Affiliation(s)
- Josh T. Cuperus
- Howard Hughes Medical
Institute, ‡Department of Genome Sciences, §Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - Russell S. Lo
- Howard Hughes Medical
Institute, ‡Department of Genome Sciences, §Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - Lucia Shumaker
- Howard Hughes Medical
Institute, ‡Department of Genome Sciences, §Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - Julia Proctor
- Howard Hughes Medical
Institute, ‡Department of Genome Sciences, §Department of Medicine, University of Washington, Seattle, Washington 98195, United States
| | - Stanley Fields
- Howard Hughes Medical
Institute, ‡Department of Genome Sciences, §Department of Medicine, University of Washington, Seattle, Washington 98195, United States
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12
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Bonney ME, Moriya H, Amon A. Aneuploid proliferation defects in yeast are not driven by copy number changes of a few dosage-sensitive genes. Genes Dev 2015; 29:898-903. [PMID: 25934502 PMCID: PMC4421978 DOI: 10.1101/gad.261743.115] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A central question is whether aneuploid phenotypes are the consequence of copy number changes of a few especially harmful genes that may be present on the extra chromosome or are caused by copy number alterations of many genes that confer no observable phenotype when varied individually. Bonney et al. used the proliferation defect exhibited by budding yeast strains carrying single additional chromosomes (disomes) to show that subtle changes in gene dosage across a chromosome can have significant phenotypic consequences. Aneuploidy—the gain or loss of one or more whole chromosome—typically has an adverse impact on organismal fitness, manifest in conditions such as Down syndrome. A central question is whether aneuploid phenotypes are the consequence of copy number changes of a few especially harmful genes that may be present on the extra chromosome or are caused by copy number alterations of many genes that confer no observable phenotype when varied individually. We used the proliferation defect exhibited by budding yeast strains carrying single additional chromosomes (disomes) to distinguish between the “few critical genes” hypothesis and the “mass action of genes” hypothesis. Our results indicate that subtle changes in gene dosage across a chromosome can have significant phenotypic consequences. We conclude that phenotypic thresholds can be crossed by mass action of copy number changes that, on their own, are benign.
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Affiliation(s)
- Megan E Bonney
- Koch Institute for Integrative Cancer Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Hisao Moriya
- Research Core for Interdisciplinary Sciences, Okayama University, Okayama 700-8530, Japan
| | - Angelika Amon
- Koch Institute for Integrative Cancer Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA;
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13
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Thierry A, Khanna V, Créno S, Lafontaine I, Ma L, Bouchier C, Dujon B. Macrotene chromosomes provide insights to a new mechanism of high-order gene amplification in eukaryotes. Nat Commun 2015; 6:6154. [PMID: 25635677 PMCID: PMC4317496 DOI: 10.1038/ncomms7154] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 12/15/2014] [Indexed: 12/30/2022] Open
Abstract
Copy number variation of chromosomal segments is now recognized as a major source of genetic polymorphism within natural populations of eukaryotes, as well as a possible cause of genetic diseases in humans, including cancer, but its molecular bases remain incompletely understood. In the baker's yeast Saccharomyces cerevisiae, a variety of low-order amplifications (segmental duplications) were observed after adaptation to limiting environmental conditions or recovery from gene dosage imbalance, and interpreted in terms of replication-based mechanisms associated or not with homologous recombination. Here we show the emergence of novel high-order amplification structures, with corresponding overexpression of embedded genes, during evolution under favourable growth conditions of severely unfit yeast cells bearing genetically disabled genomes. Such events form massively extended chromosomes, which we propose to call macrotene, whose characteristics suggest the products of intrachromosomal rolling-circle type of replication structures, probably initiated by increased accidental template switches under important cellular stress conditions.
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Affiliation(s)
- Agnès Thierry
- Institut Pasteur, Unité de Génétique moléculaire des levures, CNRS UMR3525, Sorbonne Universités, UPMC, Univ. Paris 06 UFR927, 25, rue du Docteur Roux, F-75724 Paris, France
| | - Varun Khanna
- Institut Pasteur, Unité de Génétique moléculaire des levures, CNRS UMR3525, Sorbonne Universités, UPMC, Univ. Paris 06 UFR927, 25, rue du Docteur Roux, F-75724 Paris, France
| | - Sophie Créno
- Institut Pasteur, Genomic platform, 28, rue du Docteur Roux, F-75724 Paris, France
| | - Ingrid Lafontaine
- Institut Pasteur, Unité de Génétique moléculaire des levures, CNRS UMR3525, Sorbonne Universités, UPMC, Univ. Paris 06 UFR927, 25, rue du Docteur Roux, F-75724 Paris, France
| | - Laurence Ma
- Institut Pasteur, Genomic platform, 28, rue du Docteur Roux, F-75724 Paris, France
| | - Christiane Bouchier
- Institut Pasteur, Genomic platform, 28, rue du Docteur Roux, F-75724 Paris, France
| | - Bernard Dujon
- Institut Pasteur, Unité de Génétique moléculaire des levures, CNRS UMR3525, Sorbonne Universités, UPMC, Univ. Paris 06 UFR927, 25, rue du Docteur Roux, F-75724 Paris, France
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14
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Siamer S, Guillas I, Shimobayashi M, Kunz C, Hall MN, Barny MA. Expression of the bacterial type III effector DspA/E in Saccharomyces cerevisiae down-regulates the sphingolipid biosynthetic pathway leading to growth arrest. J Biol Chem 2014; 289:18466-77. [PMID: 24828506 DOI: 10.1074/jbc.m114.562769] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Erwinia amylovora, the bacterium responsible for fire blight, relies on a type III secretion system and a single injected effector, DspA/E, to induce disease in host plants. DspA/E belongs to the widespread AvrE family of type III effectors that suppress plant defense responses and promote bacterial growth following infection. Ectopic expression of DspA/E in plant or in Saccharomyces cerevisiae is toxic, indicating that DspA/E likely targets a cellular process conserved between yeast and plant. To unravel the mode of action of DspA/E, we screened the Euroscarf S. cerevisiae library for mutants resistant to DspA/E-induced growth arrest. The most resistant mutants (Δsur4, Δfen1, Δipt1, Δskn1, Δcsg1, Δcsg2, Δorm1, and Δorm2) were impaired in the sphingolipid biosynthetic pathway. Exogenously supplied sphingolipid precursors such as the long chain bases (LCBs) phytosphingosine and dihydrosphingosine also suppressed the DspA/E-induced yeast growth defect. Expression of DspA/E in yeast down-regulated LCB biosynthesis and induced a rapid decrease in LCB levels, indicating that serine palmitoyltransferase (SPT), the first and rate-limiting enzyme of the sphingolipid biosynthetic pathway, was repressed. SPT down-regulation was mediated by dephosphorylation and activation of Orm proteins that negatively regulate SPT. A Δcdc55 mutation affecting Cdc55-PP2A protein phosphatase activity prevented Orm dephosphorylation and suppressed DspA/E-induced growth arrest.
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Affiliation(s)
- Sabrina Siamer
- From the Institut National de la Recherche Agronomique UMR1392, Institut d'Ecologie et des Sciences de l'Environnement, Université Pierre et Marie Curie (UPMC), Bât A 7ème Etage Case 237, 7 Quai St.-Bernard, 75252 Paris, France, Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Isabelle Guillas
- Sorbonne Universités, UMR1166, Institut National de la Santé et de la recherche médicale-UPMC, Pitié-Salpétrière University Hospital, F75013, Paris, France
| | | | - Caroline Kunz
- Sorbonne Universités, UPMC University Paris 06, UFR 927, F-75005 Paris, France, and Muséum National d'Histoire Naturelle, UMR7245, Molécules de Communication et Adaptation des Micro-organismes, F-75005 Paris, France
| | - Michael N Hall
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Marie-Anne Barny
- From the Institut National de la Recherche Agronomique UMR1392, Institut d'Ecologie et des Sciences de l'Environnement, Université Pierre et Marie Curie (UPMC), Bât A 7ème Etage Case 237, 7 Quai St.-Bernard, 75252 Paris, France,
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15
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Makanae K, Kintaka R, Makino T, Kitano H, Moriya H. Identification of dosage-sensitive genes in Saccharomyces cerevisiae using the genetic tug-of-war method. Genome Res 2012; 23:300-11. [PMID: 23275495 PMCID: PMC3561871 DOI: 10.1101/gr.146662.112] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Gene overexpression beyond a permissible limit causes defects in cellular functions. However, the permissible limits of most genes are unclear. Previously, we developed a genetic method designated genetic tug-of-war (gTOW) to measure the copy number limit of overexpression of a target gene. In the current study, we applied gTOW to the analysis of all protein-coding genes in the budding yeast Saccharomyces cerevisiae. We showed that the yeast cellular system was robust against an increase in the copy number by up to 100 copies in >80% of the genes. After frameshift and segmentation analyses, we isolated 115 dosage-sensitive genes (DSGs) with copy number limits of 10 or less. DSGs contained a significant number of genes involved in cytoskeletal organization and intracellular transport. DSGs tended to be highly expressed and to encode protein complex members. We demonstrated that the protein burden caused the dosage sensitivity of highly expressed genes using a gTOW experiment in which the open reading frame was replaced with GFP. Dosage sensitivities of some DSGs were rescued by the simultaneous increase in the copy numbers of partner genes, indicating that stoichiometric imbalances among complexes cause dosage sensitivity. The results obtained in this study will provide basic knowledge about the physiology of chromosomal abnormalities and the evolution of chromosomal composition.
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Affiliation(s)
- Koji Makanae
- Research Core for Interdisciplinary Sciences, Okayama University, Okayama 700-8530, Japan
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Abstract
Novel protein-coding genes can arise either through re-organization of pre-existing genes or de novo1,2. Processes involving re-organization of pre-existing genes, notably following gene duplication, have been extensively described1,2. In contrast, de novo gene birth remains poorly understood, mainly because translation of sequences devoid of genes, or “non-genic” sequences, is expected to produce insignificant polypeptides rather than proteins with specific biological functions1,3-6. Here, we formalize an evolutionary model according to which functional genes evolve de novo through transitory proto-genes4 generated by widespread translational activity in non-genic sequences. Testing this model at genome-scale in Saccharomyces cerevisiae, we detect translation of hundreds of short species-specific open reading frames (ORFs) located in non-genic sequences. These translation events appear to provide adaptive potential7, as suggested by their differential regulation upon stress and by signatures of retention by natural selection. In line with our model, we establish that S. cerevisiae ORFs can be placed within an evolutionary continuum ranging from non-genic sequences to genes. We identify ~1,900 candidate proto-genes among S. cerevisiae ORFs and find that de novo gene birth from such a reservoir may be more prevalent than sporadic gene duplication. Our work illustrates that evolution exploits seemingly dispensable sequences to generate adaptive functional innovation.
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Siamer S, Patrit O, Fagard M, Belgareh-Touzé N, Barny MA. Expressing the Erwinia amylovora type III effector DspA/E in the yeast Saccharomyces cerevisiae strongly alters cellular trafficking. FEBS Open Bio 2011; 1:23-8. [PMID: 23650572 PMCID: PMC3642059 DOI: 10.1016/j.fob.2011.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 11/02/2011] [Accepted: 11/03/2011] [Indexed: 11/18/2022] Open
Abstract
Erwinia amylovora is responsible for fire blight, a necrotic disease of apples and pears. E. amylovora relies on a type III secretion system (T3SS) to induce disease on host plants. DspA/E belongs to the AvrE family of type III effector. Effectors of the AvrE family are injected via the T3SS in plant cell and are important to promote bacterial growth following infection and to suppress plant defense responses. Their mode of action in the plant cells is unknown. Here we study the physiological effects induced by dspA/E expression in the yeast Saccharomyces cerevisiae. Expression of dspA/E in the yeast inhibits cell growth. This growth inhibition is associated with perturbations of the actin cytoskeleton and endocytosis.
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Affiliation(s)
- Sabrina Siamer
- INRA, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- UPMC, Université Paris VI, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- AgroParisTech, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
| | - Oriane Patrit
- INRA, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- UPMC, Université Paris VI, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- AgroParisTech, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
| | - Mathilde Fagard
- INRA, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- UPMC, Université Paris VI, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- AgroParisTech, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
| | - Naïma Belgareh-Touzé
- FRE 3354 CNRS/UPMC, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Marie-Anne Barny
- INRA, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- UPMC, Université Paris VI, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- AgroParisTech, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France
- Corresponding author at: AgroParisTech, UMR217, LIPP, 16 rue Claude Bernard, 75231 Paris cedex 05, France. Fax: +33 1 44 08 16 98.
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Wingler LM, Cornish VW. A Library Approach for the Discovery of Customized Yeast Three-Hybrid Counter Selections. Chembiochem 2011; 12:715-7. [DOI: 10.1002/cbic.201000543] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Indexed: 11/06/2022]
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Dutoit R, Dubois E, Jacobs E. Selection systems based on dominant-negative transcription factors for precise genetic engineering. Nucleic Acids Res 2010; 38:e183. [PMID: 20702421 PMCID: PMC2965260 DOI: 10.1093/nar/gkq708] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Diverse tools are available for performing genetic modifications of microorganisms. However, new methods still need to be developed for performing precise genomic engineering without introducing any undesirable side-alteration. Indeed for functional analyses of genomic elements, as well as for some industrial applications, only the desired mutation should be introduced at the locus considered. This article describes a new approach fulfilling these requirements, based on the use of selection systems consisting in truncated genes encoding dominant-negative transcription factors. We have demonstrated dominant-negative effects mediated by truncated Gal4p and Arg81p proteins in Saccharomyces cerevisiae, interfering with galactose and arginine metabolic pathways, respectively. These genes can be used as positive and negative markers, since they provoke both growth inhibition on substrates and resistance to specific drugs. These selection markers have been successfully used for precisely deleting HO and URA3 in wild yeasts. This genetic engineering approach could be extended to other microorganisms.
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Affiliation(s)
- Raphaël Dutoit
- Institut de Recherches Microbiologiques JM Wiame and Laboratoire de Microbiologie de l'Université Libre de Bruxelles, 1 avenue Emile Gryson, BE1070 Belgium.
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20
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Veitia RA. A generalized model of gene dosage and dominant negative effects in macromolecular complexes. FASEB J 2009; 24:994-1002. [PMID: 20007508 DOI: 10.1096/fj.09-146969] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Most genes and their corresponding products are supposed to be involved in genetic or biochemical interactions. A typical example is provided by macromolecular complexes, which may contain tens of proteins in defined stoichiometric proportions. Stoichiometric imbalances in such complexes can be a source of abnormal phenotypes. Comparable effects can also arise from negative dominance/transdominance, even though the underlying mechanisms are different. Here I propose a general yet simple biochemical model accounting for the effects of dosage changes and weak dominant/transdominant negative mutations in macromolecular complexes. The molecular alterations studied are predicted to lead to synergistic effects that can drive total multimer concentration and/or activity in a multiple heterozygote below a critical threshold required to ensure a normal phenotype, thus providing an explanation for the phenomenon of unlinked noncomplementation or nonallelic noncomplementation. The model also helps in understanding the basis of heterosis and the long-term consequences of gene dosage alterations and weak dominant/transdominant negative effects. Indeed, it can explain the observed extensive retention of paralogs in polyploids. Finally, because the effects of weak single-gene alterations can escape selection, they may accumulate in the population. This situation has important evolutionary consequences and may eventually lead to reproductive isolation and speciation.-Veitia, R. A. A generalized model of gene dosage and dominant negative effects in macromolecular complexes.
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Affiliation(s)
- Reiner A Veitia
- Institut Jacques Monod, Unité Mixte de Recherche 7592, Centre National de la Recherche Scientifique, and Université Paris-Diderot/Paris 7, Paris, France.
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Abstract
The idea of dominant mutations that interfere with the activity of a normal gene product has been known for more than 80 years-the famous Muller's antimorphs. However, only over half a century later, the mechanistic bases of dominant negative mutations (DNMs) were defined in a systematic way by Ira Herskowitz. Most analyses of DNMs consider only intralocus (interallelic) interactions. The typical textbook explanation invokes a defective subunit, which poisons a homo-dimer or a homo-oligomer. More complex cases exist and the quantitative dimension of this phenomenon will be explored here. The basic ideas underlying DN effects can be (and should be) extended to included epistatic (interloci) interactions. Indeed, poisoning heteromeric macromolecular complexes is per se a matter of 'transdominant' negative effects. In this context, non-allelic non-complementation is also considered. Given the importance of DNMs in human disease and in the study of gene function, understanding how they work is essential for understanding pathology and for the design of effective DN molecules that can also prove useful in therapeutics. Finally, the existence and potential relevance of an increasing number of physiological DN protein isoforms is briefly discussed.
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Affiliation(s)
- Reiner A Veitia
- Institut Jacques Monod, CNRS-UMR 7592, Bâtiment Buffon, 15 Rue Hélène Brion, Paris Cedex 13, France.
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Skružný M, Schneider C, Rácz A, Weng J, Tollervey D, Hurt E. An endoribonuclease functionally linked to perinuclear mRNP quality control associates with the nuclear pore complexes. PLoS Biol 2009; 7:e8. [PMID: 19127978 PMCID: PMC2613419 DOI: 10.1371/journal.pbio.1000008] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Accepted: 11/20/2008] [Indexed: 11/24/2022] Open
Abstract
Nuclear mRNA export is a crucial step in eukaryotic gene expression, which is in yeast coupled to cotranscriptional messenger ribonucleoprotein particle (mRNP) assembly and surveillance. Several surveillance systems that monitor nuclear mRNP biogenesis and export have been described, but the mechanism by which the improper mRNPs are recognized and eliminated remains poorly understood. Here we report that the conserved PIN domain protein Swt1 is an RNA endonuclease that participates in quality control of nuclear mRNPs and can associate with the nuclear pore complex (NPC). Swt1 showed endoribonuclease activity in vitro that was inhibited by a point mutation in the predicted catalytic site. Swt1 lacked clear sequence specificity but showed a strong preference for single-stranded regions. Genetic interactions were found between Swt1 and the THO/TREX and TREX-2 complexes, and with components of the perinuclear mRNP surveillance system, Mlp1, Nup60, and Esc1. Inhibition of the nuclease activity of Swt1 increased the levels and cytoplasmic leakage of unspliced aberrant pre-mRNA, and induced robust nuclear poly(A)+ RNA accumulation in mlp1Δ and esc1Δ strains. Overexpression of Swt1 also caused strong nuclear poly(A)+ RNA accumulation. Swt1 is normally distributed throughout the nucleus and cytoplasm but becomes concentrated at nuclear pore complexes (NPCs) in the nup133Δ mutant, which causes NPC clustering and defects in mRNP export. The data suggest that Swt1 endoribonuclease might be transiently recruited to NPCs to initiate the degradation of defective pre-mRNPs or mRNPs trapped at nuclear periphery in order to avoid their cytoplasmic export and translation. Nuclear export of messenger RNA (mRNA) is a crucial step during eukaryotic gene expression. Newly synthesized precursor mRNAs are processed during synthesis, packaged into messenger ribonucleoprotein particles (mRNPs), and transported through the nuclear pore complex to the cytoplasm. To avoid nuclear export of aberrant transcripts and their translation in the cytoplasm, the quality of nuclear mRNPs is monitored by several surveillance systems. Here we show that the conserved protein Swt1 is an RNA endoribonuclease, an RNA-degrading enzyme, that becomes indispensable when factors involved in co-transcriptional mRNP assembly and mRNP quality control are mutated. We found that inactive Swt1 increases the levels and cytoplasmic leakage of aberrant, unprocessed precursor mRNA. Moreover, Swt1 accumulates at the nuclear pore complexes in the pore-clustering nup133Δ mutant. Thus, we speculate that the Swt1 endoribonuclease can be transiently recruited to the nuclear periphery to initiate the degradation of defective, pore-trapped pre-mRNPs in order to prevent their inappropriate cytoplasmic export. When errors in messenger RNA processing or packaging occur along the path from the site of transcription to the nuclear pore complex, the conserved RNA-degrading enzyme Swt1 comes into the game.
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Affiliation(s)
- Michal Skružný
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Claudia Schneider
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, Scotland
| | - Attila Rácz
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Julan Weng
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - David Tollervey
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, Scotland
| | - Ed Hurt
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
- * To whom correspondence should be addressed. E-mail:
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Maya D, Quintero MJ, de la Cruz Muñoz-Centeno M, Chávez S. Systems for applied gene control in Saccharomyces cerevisiae. Biotechnol Lett 2008; 30:979-87. [DOI: 10.1007/s10529-008-9647-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 01/14/2008] [Accepted: 01/17/2008] [Indexed: 01/06/2023]
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Wu D, Townsley E, Tartakoff AM. Covert genetic selections to optimize phenotypes. PLoS One 2007; 2:e1200. [PMID: 18030334 PMCID: PMC2075469 DOI: 10.1371/journal.pone.0001200] [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: 08/20/2007] [Accepted: 10/08/2007] [Indexed: 11/21/2022] Open
Abstract
In many high complexity systems (cells, organisms, institutions, societies, economies, etc.), it is unclear which components should be regulated to affect overall performance. To identify and prioritize molecular targets which impact cellular phenotypes, we have developed a selection procedure (“SPI”–single promoting/inhibiting target identification) which monitors the abundance of ectopic cDNAs. We have used this approach to identify growth regulators. For this purpose, complex pools of S. cerevisiae cDNA transformants were established and we quantitated the evolution of the spectrum of cDNAs which was initially present. These data emphasized the importance of translation initiation and ER-Golgi traffic for growth. SPI provides functional insight into the stability of cellular phenotypes under circumstances in which established genetic approaches cannot be implemented. It provides a functional “synthetic genetic signature” for each state of the cell (i.e. genotype and environment) by surveying complex genetic libraries, and does not require specialized arrays of cDNAs/shRNAs, deletion strains, direct assessment of clonal growth or even a conditional phenotype. Moreover, it establishes a hierarchy of importance of those targets which can contribute, either positively or negatively, to modify the prevailing phenotype. Extensions of these proof-of-principle experiments to other cell types should provide a novel and powerful approach to analyze multiple aspects of the basic biology of yeast and animal cells as well as clinically-relevant issues.
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Affiliation(s)
- Di Wu
- Monash Institute of Medical Research, Monash University, Monash Medical Centre, Melbourne, Victoria, Australia
| | - Elizabeth Townsley
- Department of Pathology, Cell Biology Program, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Alan Michael Tartakoff
- Department of Pathology, Cell Biology Program, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- * To whom correspondence should be addressed. E-mail:
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Fairhead C, Dujon B. Structure of Kluyveromyces lactis subtelomeres: duplications and gene content. FEMS Yeast Res 2006; 6:428-41. [PMID: 16630283 DOI: 10.1111/j.1567-1364.2006.00033.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We have constructed a map of the duplicated regions of Kluyveromyces lactis subtelomeres. Seven out of 12 subtelomeres contain an almost identical 9 kb long segment starting from the end. This segment is bordered by a long terminal repeat element. Two of the subtelomeres share sequence similarity that extends over a total of 20 kb. The other subtelomeres also contain duplicated regions of 1-6 kb. Nonduplicated regions contain unique genes and genes from paralog families. All duplicated segments are in the same orientation with respect to the telomere, probably as a result of genetic exchange. We map the only two copies of retrotransposons in the genome, in subtelomeres. Low-complexity gene sequences that encode threonine- and serine-rich peptides are associated with the subtelomeres of K. lactis, as in Saccharomyces cerevisiae. The ubiquity of these sequences in hemiascomycete genomes, and the propensity they have to encode proteins with extracellular localization, make these genes ideal candidates for fast evolving 'contingency' genes involved in the adaptation of a species to its environment.
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Affiliation(s)
- Cécile Fairhead
- Unité de Génétique Moléculaire des Levures, Département Structure et Dynamique des Génomes, Institut Pasteur, Paris, France.
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26
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David L, Huber W, Granovskaia M, Toedling J, Palm CJ, Bofkin L, Jones T, Davis RW, Steinmetz LM. A high-resolution map of transcription in the yeast genome. Proc Natl Acad Sci U S A 2006; 103:5320-5. [PMID: 16569694 PMCID: PMC1414796 DOI: 10.1073/pnas.0601091103] [Citation(s) in RCA: 506] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
There is abundant transcription from eukaryotic genomes unaccounted for by protein coding genes. A high-resolution genome-wide survey of transcription in a well annotated genome will help relate transcriptional complexity to function. By quantifying RNA expression on both strands of the complete genome of Saccharomyces cerevisiae using a high-density oligonucleotide tiling array, this study identifies the boundary, structure, and level of coding and noncoding transcripts. A total of 85% of the genome is expressed in rich media. Apart from expected transcripts, we found operon-like transcripts, transcripts from neighboring genes not separated by intergenic regions, and genes with complex transcriptional architecture where different parts of the same gene are expressed at different levels. We mapped the positions of 3' and 5' UTRs of coding genes and identified hundreds of RNA transcripts distinct from annotated genes. These nonannotated transcripts, on average, have lower sequence conservation and lower rates of deletion phenotype than protein coding genes. Many other transcripts overlap known genes in antisense orientation, and for these pairs global correlations were discovered: UTR lengths correlated with gene function, localization, and requirements for regulation; antisense transcripts overlapped 3' UTRs more than 5' UTRs; UTRs with overlapping antisense tended to be longer; and the presence of antisense associated with gene function. These findings may suggest a regulatory role of antisense transcription in S. cerevisiae. Moreover, the data show that even this well studied genome has transcriptional complexity far beyond current annotation.
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Affiliation(s)
- Lior David
- *Stanford Genome Technology Center and Department of Biochemistry, Stanford University, Palo Alto, CA 94304
| | - Wolfgang Huber
- European Bioinformatics Institute, European Molecular Biology Laboratory, Cambridge CB10 1SD, United Kingdom; and
| | | | - Joern Toedling
- European Bioinformatics Institute, European Molecular Biology Laboratory, Cambridge CB10 1SD, United Kingdom; and
| | - Curtis J. Palm
- *Stanford Genome Technology Center and Department of Biochemistry, Stanford University, Palo Alto, CA 94304
| | - Lee Bofkin
- European Bioinformatics Institute, European Molecular Biology Laboratory, Cambridge CB10 1SD, United Kingdom; and
| | - Ted Jones
- *Stanford Genome Technology Center and Department of Biochemistry, Stanford University, Palo Alto, CA 94304
| | - Ronald W. Davis
- *Stanford Genome Technology Center and Department of Biochemistry, Stanford University, Palo Alto, CA 94304
- To whom correspondence may be addressed. E-mail:
or
| | - Lars M. Steinmetz
- *Stanford Genome Technology Center and Department of Biochemistry, Stanford University, Palo Alto, CA 94304
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
- To whom correspondence may be addressed. E-mail:
or
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Sopko R, Huang D, Preston N, Chua G, Papp B, Kafadar K, Snyder M, Oliver SG, Cyert M, Hughes TR, Boone C, Andrews B. Mapping pathways and phenotypes by systematic gene overexpression. Mol Cell 2006; 21:319-30. [PMID: 16455487 DOI: 10.1016/j.molcel.2005.12.011] [Citation(s) in RCA: 493] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2005] [Revised: 11/24/2005] [Accepted: 12/07/2005] [Indexed: 11/23/2022]
Abstract
Many disease states result from gene overexpression, often in a specific genetic context. To explore gene overexpression phenotypes systematically, we assembled an array of 5280 yeast strains, each containing an inducible copy of an S. cerevisiae gene, covering >80% of the genome. Approximately 15% of the overexpressed genes (769) reduced growth rate. This gene set was enriched for cell cycle-regulated genes, signaling molecules, and transcription factors. Overexpression of most toxic genes resulted in phenotypes different from known deletion mutant phenotypes, suggesting that overexpression phenotypes usually reflect a specific regulatory imbalance rather than disruption of protein complex stoichiometry. Global overexpression effects were also assayed in the context of a cyclin-dependent kinase mutant (pho85Delta). The resultant gene set was enriched for Pho85p targets and identified the yeast calcineurin-responsive transcription factor Crz1p as a substrate. Large-scale application of this approach should provide a strategy for identifying target molecules regulated by specific signaling pathways.
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Affiliation(s)
- Richelle Sopko
- Department of Medical Genetics and Microbiology, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
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Gelperin DM, White MA, Wilkinson ML, Kon Y, Kung LA, Wise KJ, Lopez-Hoyo N, Jiang L, Piccirillo S, Yu H, Gerstein M, Dumont ME, Phizicky EM, Snyder M, Grayhack EJ. Biochemical and genetic analysis of the yeast proteome with a movable ORF collection. Genes Dev 2005; 19:2816-26. [PMID: 16322557 PMCID: PMC1315389 DOI: 10.1101/gad.1362105] [Citation(s) in RCA: 390] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Accepted: 09/26/2005] [Indexed: 11/24/2022]
Abstract
Functional analysis of the proteome is an essential part of genomic research. To facilitate different proteomic approaches, a MORF (moveable ORF) library of 5854 yeast expression plasmids was constructed, each expressing a sequence-verified ORF as a C-terminal ORF fusion protein, under regulated control. Analysis of 5573 MORFs demonstrates that nearly all verified ORFs are expressed, suggests the authenticity of 48 ORFs characterized as dubious, and implicates specific processes including cytoskeletal organization and transcriptional control in growth inhibition caused by overexpression. Global analysis of glycosylated proteins identifies 109 new confirmed N-linked and 345 candidate glycoproteins, nearly doubling the known yeast glycome.
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Affiliation(s)
- Daniel M Gelperin
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
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