scholarly journals Genome-wide mapping of unexplored essential regions in the Saccharomyces cerevisiae genome: evidence for hidden synthetic lethal combinations in a genetic interaction network

2014 ◽  
Vol 42 (15) ◽  
pp. 9838-9853 ◽  
Author(s):  
Saeed Kaboli ◽  
Takuya Yamakawa ◽  
Keisuke Sunada ◽  
Tao Takagaki ◽  
Yu Sasano ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Interaction ◽  
Interaction Network ◽  
Essential Genes ◽  
Genetic Interactions ◽  
Lethal Gene ◽  
Synthetic Lethal ◽  
Genome Wide ◽  
A Genome ◽  
Wide Scale

Abstract Despite systematic approaches to mapping networks of genetic interactions in Saccharomyces cerevisiae, exploration of genetic interactions on a genome-wide scale has been limited. The S. cerevisiae haploid genome has 110 regions that are longer than 10 kb but harbor only non-essential genes. Here, we attempted to delete these regions by PCR-mediated chromosomal deletion technology (PCD), which enables chromosomal segments to be deleted by a one-step transformation. Thirty-three of the 110 regions could be deleted, but the remaining 77 regions could not. To determine whether the 77 undeletable regions are essential, we successfully converted 67 of them to mini-chromosomes marked with URA3 using PCR-mediated chromosome splitting technology and conducted a mitotic loss assay of the mini-chromosomes. Fifty-six of the 67 regions were found to be essential for cell growth, and 49 of these carried co-lethal gene pair(s) that were not previously been detected by synthetic genetic array analysis. This result implies that regions harboring only non-essential genes contain unidentified synthetic lethal combinations at an unexpectedly high frequency, revealing a novel landscape of genetic interactions in the S. cerevisiae genome. Furthermore, this study indicates that segmental deletion might be exploited for not only revealing genome function but also breeding stress-tolerant strains.

scholarly journals Genome-wide synthetic lethal CRISPR screen identifies FIS1 as a genetic interactor of ALS-linked C9ORF72

2019 ◽  
Author(s):  
Noori Chai ◽  
Michael S. Haney ◽  
Julien Couthouis ◽  
David W. Morgens ◽  
Alyssa Benjamin ◽  
...  
Keyword(s):  
Genetic Interaction ◽  
Mitochondrial Fission ◽  
Loss Of Function ◽  
Synthetic Lethal ◽  
Genome Wide ◽  
A Genome ◽  
Crispr Screen ◽  
Insight Into ◽  
Mitochondrial Membrane Protein ◽  
Lateral Sclerosis

AbstractMutations in the C9ORF72 gene are the most common cause of amyotrophic lateral sclerosis (ALS). Both toxic gain of function and loss of function pathogenic mechanisms have been proposed. Accruing evidence from mouse knockout studies point to a role for C9ORF72 as a regulator of immune function. To provide further insight into its cellular function, we performed a genome-wide synthetic lethal CRISPR screen in human myeloid cells lacking C9ORF72. We discovered a strong synthetic lethal genetic interaction between C9ORF72 and FIS1, which encodes a mitochondrial membrane protein involved in mitochondrial fission and mitophagy. Mass spectrometry experiments revealed that in C9ORF72 knockout cells, FIS1 strongly bound to a class of immune regulators that activate the receptor for advanced glycation end (RAGE) products and trigger inflammatory cascades. These findings present a novel genetic interactor for C9ORF72 and suggest a compensatory role for FIS1 in suppressing inflammatory signaling in the absence of C9ORF72.

scholarly journals Genome-wide Cas9 binding specificity in Saccharomyces cerevisiae

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9442 ◽  
Author(s):  
Zachary J. Waldrip ◽  
Piroon Jenjaroenpun ◽  
Oktawia DeYoung ◽  
Intawat Nookaew ◽  
Sean D. Taverna ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Specificity ◽  
Genomic Locus ◽  
Site Specific ◽  
Guide Rna ◽  
Genome Wide ◽  
A Genome ◽  
Wide Scale ◽  
Chromosome Iii ◽  
Genomic Editing

The CRISPR system has become heavily utilized in biomedical research as a tool for genomic editing as well as for site-specific chromosomal localization of specific proteins. For example, we developed a CRISPR-based methodology for enriching a specific genomic locus of interest for proteomic analysis in Saccharomyces cerevisiae, which utilized a guide RNA-targeted, catalytically dead Cas9 (dCas9) as an affinity reagent. To more comprehensively evaluate the genomic specificity of using dCas9 as a site-specific tool for chromosomal studies, we performed dCas9-mediated locus enrichment followed by next-generation sequencing on a genome-wide scale. As a test locus, we used the ARS305 origin of replication on chromosome III in S. cerevisiae. We found that enrichment of this site is highly specific, with virtually no off-target enrichment of unique genomic sequences. The high specificity of genomic localization and enrichment suggests that dCas9-mediated technologies have promising potential for site-specific chromosomal studies in organisms with relatively small genomes such as yeasts.

scholarly journals A one-step tRNA-CRISPR system for genome-wide genetic interaction mapping in mammalian cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yulei Zhao ◽  
Kathrin Tyrishkin ◽  
Calvin Sjaarda ◽  
Prem Khanal ◽  
Jeff Stafford ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Drug Targets ◽  
Genetic Interaction ◽  
Genetic Interactions ◽  
Cancer Treatments ◽  
Genome Wide ◽  
A Genome ◽  
High Efficient ◽  
One Step ◽  
Screening Accuracy

Abstract Mapping genetic interactions in mammalian cells is limited due to technical obstacles. Here we describe a method called TCGI (tRNA-CRISPR for genetic interactions) to generate a high-efficient, barcode-free and scalable pairwise CRISPR libraries in mammalian cells for identifying genetic interactions. We have generated a genome- wide library to identify genes genetically interacting with TAZ in cell viability regulation. Validation of candidate synergistic genes reveals the screening accuracy of 85% and TAZ-MCL1 is characterized as combinational drug targets for non-small cell lung cancer treatments. TCGI has dramatically improved the current methods for mapping genetic interactions and screening drug targets for combinational therapies.

scholarly journals Integrative analysis of large-scale loss-of-function screens identifies robust cancer-associated genetic interactions

2019 ◽  
Author(s):  
Christopher J. Lord ◽  
Niall Quinn ◽  
Colm J. Ryan
Keyword(s):  
Protein Interactions ◽  
Large Scale ◽  
Genetic Interaction ◽  
Interaction Network ◽  
Genetic Interactions ◽  
Molecular Heterogeneity ◽  
Loss Of Function ◽  
Driver Genes ◽  
Lethal Effects ◽  
Synthetic Lethal

AbstractGenetic interactions, such as synthetic lethal effects, can now be systematically identified in cancer cell lines using high-throughput genetic perturbation screens. Despite this advance, few genetic interactions have been reproduced across multiple studies and many appear highly context-specific. Understanding which genetic interactions are robust in the face of the molecular heterogeneity observed in tumours and what factors influence this robustness could streamline the identification of therapeutic targets. Here, we develop a computational approach to identify robust genetic interactions that can be reproduced across independent experiments and across non-overlapping cell line panels. We used this approach to evaluate >140,000 potential genetic interactions involving cancer driver genes and identified 1,520 that are significant in at least one study but only 220 that reproduce across multiple studies. Analysis of these interactions demonstrated that: (i) oncogene addiction effects are more robust than oncogene-related synthetic lethal effects; and (ii) robust genetic interactions in cancer are enriched for gene pairs whose protein products physically interact. This suggests that protein-protein interactions can be used not only to understand the mechanistic basis of genetic interaction effects, but also to prioritise robust targets for further development. To explore the utility of this approach, we used a protein-protein interaction network to guide the search for robust synthetic lethal interactions associated with passenger gene alterations and validated two novel robust synthetic lethalities.

scholarly journals Genome-Wide Saturation Mutagenesis of Burkholderia pseudomallei K96243 Predicts Essential Genes and Novel Targets for Antimicrobial Development

mBio ◽  
2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Madeleine G. Moule ◽  
Claudia M. Hemsley ◽  
Qihui Seet ◽  
José Afonso Guerra-Assunção ◽  
Jiali Lim ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Treatment Options ◽  
Insertion Site ◽  
Essential Genes ◽  
Natural Resistance ◽  
Saturation Mutagenesis ◽  
Lethal Gene ◽  
Content Type ◽  
Genome Wide ◽  
A Genome

ABSTRACT Burkholderia pseudomallei is the causative agent of melioidosis, an often fatal infectious disease for which there is no vaccine. B. pseudomallei is listed as a tier 1 select agent, and as current therapeutic options are limited due to its natural resistance to most antibiotics, the development of new antimicrobial therapies is imperative. To identify drug targets and better understand the complex B. pseudomallei genome, we sought a genome-wide approach to identify lethal gene targets. As B. pseudomallei has an unusually large genome spread over two chromosomes, an extensive screen was required to achieve a comprehensive analysis. Here we describe transposon-directed insertion site sequencing (TraDIS) of a library of over 106 transposon insertion mutants, which provides the level of genome saturation required to identify essential genes. Using this technique, we have identified a set of 505 genes that are predicted to be essential in B. pseudomallei K96243. To validate our screen, three genes predicted to be essential, pyrH, accA, and sodB, and a gene predicted to be nonessential, bpss0370, were independently investigated through the generation of conditional mutants. The conditional mutants confirmed the TraDIS predictions, showing that we have generated a list of genes predicted to be essential and demonstrating that this technique can be used to analyze complex genomes and thus be more widely applied. IMPORTANCE Burkholderia pseudomallei is a lethal human pathogen that is considered a potential bioterrorism threat and has limited treatment options due to an unusually high natural resistance to most antibiotics. We have identified a set of genes that are required for bacterial growth and thus are excellent candidates against which to develop potential novel antibiotics. To validate our approach, we constructed four mutants in which gene expression can be turned on and off conditionally to confirm that these genes are required for the bacteria to survive.

scholarly journals Functional genomics in yeast

2007 ◽  
Vol 28 (2) ◽  
pp. 51
Author(s):  
Ian W Dawes ◽  
Geoffrey D Kornfeld ◽  
Gabriel G Perrone
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Functional Genomics ◽  
Genome Sequencing ◽  
Genome Sequencing Project ◽  
Sequencing Project ◽  
Cellular Processes ◽  
Genome Wide ◽  
A Genome ◽  
Wide Scale ◽  
And Function

Completion of the Saccharomyces cerevisiae genome sequencing project in 1996 led to an incredible explosion of research on basic cellular processes and has provided the opportunity to determine how genes and their products are regulated and function on a genome-wide scale. The technologies that were developed from this provided an incredible array of tools to study cellular processes in great detail and were a paradigm for developments from subsequent sequencing projects.

scholarly journals The conserved elongation factor Spn1 is required for normal transcription, histone modifications, and splicing in Saccharomyces cerevisiae

2020 ◽  
Vol 48 (18) ◽  
pp. 10241-10258 ◽  
Author(s):  
Natalia I Reim ◽  
James Chuang ◽  
Dhawal Jain ◽  
Burak H Alver ◽  
Peter J Park ◽  
...  
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Elongation Factor ◽  
Mrna Levels ◽  
Chromatin Dynamics ◽  
Genome Wide ◽  
A Genome ◽  
Highly Expressed Genes ◽  
Wide Scale

Abstract Spn1/Iws1 is a conserved protein involved in transcription and chromatin dynamics, yet its general in vivo requirement for these functions is unknown. Using a Spn1 depletion system in Saccharomyces cerevisiae, we demonstrate that Spn1 broadly influences several aspects of gene expression on a genome-wide scale. We show that Spn1 is globally required for normal mRNA levels and for normal splicing of ribosomal protein transcripts. Furthermore, Spn1 maintains the localization of H3K36 and H3K4 methylation across the genome and is required for normal histone levels at highly expressed genes. Finally, we show that the association of Spn1 with the transcription machinery is strongly dependent on its binding partner, Spt6, while the association of Spt6 and Set2 with transcribed regions is partially dependent on Spn1. Taken together, our results show that Spn1 affects multiple aspects of gene expression and provide additional evidence that it functions as a histone chaperone in vivo.

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