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Adaptive Response of Saccharomyces Hosts to Totiviridae L-A dsRNA Viruses Is Achieved through Intrinsically Balanced Action of Targeted Transcription Factors. J Fungi (Basel) 2022; 8:jof8040381. [PMID: 35448612 PMCID: PMC9028071 DOI: 10.3390/jof8040381] [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: 03/21/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 11/17/2022] Open
Abstract
Totiviridae L-A virus is a widespread yeast dsRNA virus. The persistence of the L-A virus alone appears to be symptomless, but the concomitant presence of a satellite M virus provides a killer trait for the host cell. The presence of L-A dsRNA is common in laboratory, industrial, and wild yeasts, but little is known about the impact of the L-A virus on the host’s gene expression. In this work, based on high-throughput RNA sequencing data analysis, the impact of the L-A virus on whole-genome expression in three different Saccharomyces paradoxus and S. cerevisiae host strains was analyzed. In the presence of the L-A virus, moderate alterations in gene expression were detected, with the least impact on respiration-deficient cells. Remarkably, the transcriptional adaptation of essential genes was limited to genes involved in ribosome biogenesis. Transcriptional responses to L-A maintenance were, nevertheless, similar to those induced upon stress or nutrient availability. Based on these data, we further dissected yeast transcriptional regulators that, in turn, modulate the cellular L-A dsRNA levels. Our findings point to totivirus-driven fine-tuning of the transcriptional landscape in yeasts and uncover signaling pathways employed by dsRNA viruses to establish the stable, yet allegedly profitless, viral infection of fungi.
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Sun L, Wu B, Zhang Z, Yan J, Liu P, Song C, Shabbir S, Zhu Q, Yang S, Peng N, He M, Tan F. Cellulosic ethanol production by consortia of Scheffersomyces stipitis and engineered Zymomonas mobilis. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:221. [PMID: 34823583 PMCID: PMC8613960 DOI: 10.1186/s13068-021-02069-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 11/10/2021] [Indexed: 05/06/2023]
Abstract
BACKGROUND As one of the clean and sustainable energies, lignocellulosic ethanol has achieved much attention around the world. The production of lignocellulosic ethanol does not compete with people for food, while the consumption of ethanol could contribute to the carbon dioxide emission reduction. However, the simultaneous transformation of glucose and xylose to ethanol is one of the key technologies for attaining cost-efficient lignocellulosic ethanol production at an industrial scale. Genetic modification of strains and constructing consortia were two approaches to resolve this issue. Compared with strain improvement, the synergistic interaction of consortia in metabolic pathways should be more useful than using each one separately. RESULTS In this study, the consortia consisting of suspended Scheffersomyces stipitis CICC1960 and Zymomonas mobilis 8b were cultivated to successfully depress carbon catabolite repression (CCR) in artificially simulated 80G40XRM. With this strategy, a 5.52% more xylose consumption and a 6.52% higher ethanol titer were achieved by the consortium, in which the inoculation ratio between S. stipitis and Z. mobilis was 1:3, compared with the Z. mobilis 8b mono-fermentation. Subsequently, one copy of the xylose metabolic genes was inserted into the Z. mobilis 8b genome to construct Z. mobilis FR2, leading to the xylose final-consumption amount and ethanol titer improvement by 15.36% and 6.81%, respectively. Finally, various corn stover hydrolysates with different sugar concentrations (glucose and xylose 60, 90, 120 g/L), were used to evaluate the fermentation performance of the consortium consisting of S. stipitis CICC1960 and Z. mobilis FR2. Fermentation results showed that a 1.56-4.59% higher ethanol titer was achieved by the consortium compared with the Z. mobilis FR2 mono-fermentation, and a 46.12-102.14% higher ethanol titer was observed in the consortium fermentation when compared with the S. stipitis CICC1960 mono-fermentation. Furthermore, qRT-PCR analysis of xylose/glucose transporter and other genes responsible for CCR explained the reason why the initial ratio inoculation of 1:3 in artificially simulated 80G40XRM had the best fermentation performance in the consortium. CONCLUSIONS The fermentation strategy used in this study, i.e., using a genetically modified consortium, had a superior performance in ethanol production, as compared with the S. stipitis CICC1960 mono-fermentation and the Z. mobilis FR2 mono-fermentation alone. This result showed that this strategy has potential for future lignocellulosic ethanol production.
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Affiliation(s)
- Lingling Sun
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Bo Wu
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
| | - Zengqin Zhang
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Jing Yan
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
| | - Panting Liu
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Chao Song
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Samina Shabbir
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Qili Zhu
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
| | - Shihui Yang
- Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Nan Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Mingxiong He
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
- Chengdu National Agricultural Science and Technology Center, Chengdu, 610221 China
| | - Furong Tan
- Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041 China
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Lagree K, Woolford CA, Huang MY, May G, McManus CJ, Solis NV, Filler SG, Mitchell AP. Roles of Candida albicans Mig1 and Mig2 in glucose repression, pathogenicity traits, and SNF1 essentiality. PLoS Genet 2020; 16:e1008582. [PMID: 31961865 PMCID: PMC6994163 DOI: 10.1371/journal.pgen.1008582] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 01/31/2020] [Accepted: 12/20/2019] [Indexed: 12/16/2022] Open
Abstract
Metabolic adaptation is linked to the ability of the opportunistic pathogen Candida albicans to colonize and cause infection in diverse host tissues. One way that C. albicans controls its metabolism is through the glucose repression pathway, where expression of alternative carbon source utilization genes is repressed in the presence of its preferred carbon source, glucose. Here we carry out genetic and gene expression studies that identify transcription factors Mig1 and Mig2 as mediators of glucose repression in C. albicans. The well-studied Mig1/2 orthologs ScMig1/2 mediate glucose repression in the yeast Saccharomyces cerevisiae; our data argue that C. albicans Mig1/2 function similarly as repressors of alternative carbon source utilization genes. However, Mig1/2 functions have several distinctive features in C. albicans. First, Mig1 and Mig2 have more co-equal roles in gene regulation than their S. cerevisiae orthologs. Second, Mig1 is regulated at the level of protein accumulation, more akin to ScMig2 than ScMig1. Third, Mig1 and Mig2 are together required for a unique aspect of C. albicans biology, the expression of several pathogenicity traits. Such Mig1/2-dependent traits include the abilities to form hyphae and biofilm, tolerance of cell wall inhibitors, and ability to damage macrophage-like cells and human endothelial cells. Finally, Mig1 is required for a puzzling feature of C. albicans biology that is not shared with S. cerevisiae: the essentiality of the Snf1 protein kinase, a central eukaryotic carbon metabolism regulator. Our results integrate Mig1 and Mig2 into the C. albicans glucose repression pathway and illuminate connections among carbon control, pathogenicity, and Snf1 essentiality. All organisms tailor genetic programs to the available nutrients, such as sources of carbon. Here we define two key regulators of the genetic programs for carbon source utilization in the fungal pathogen Candida albicans. The two regulators have many shared roles, yet are partially specialized to control carbon acquisition and metabolism, respectively. In addition, the regulators together control traits associated with pathogenicity, an indication that carbon regulation is integrated into the pathogenicity program. Finally, the regulators help to explain a long-standing riddle—that the central carbon regulator Snf1 is essential for C. albicans viability.
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Affiliation(s)
- Katherine Lagree
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Carol A. Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Manning Y. Huang
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Gemma May
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - C. Joel McManus
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Norma V. Solis
- Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, United States of America
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Scott G. Filler
- Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, United States of America
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States of America
| | - Aaron P. Mitchell
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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Espinosa MI, Williams TC, Pretorius IS, Paulsen IT. Benchmarking two Saccharomyces cerevisiae laboratory strains for growth and transcriptional response to methanol. Synth Syst Biotechnol 2019; 4:180-188. [PMID: 31667368 PMCID: PMC6807065 DOI: 10.1016/j.synbio.2019.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 09/27/2019] [Accepted: 10/03/2019] [Indexed: 11/21/2022] Open
Abstract
One-carbon compounds, such as methanol, are becoming potential alternatives to sugars as feedstocks for the biological production of chemicals, fuels, foods, and pharmaceuticals. Efficient biological production often requires extensive genetic manipulation of a microbial host strain, making well-characterised and genetically-tractable model organisms like the yeast Saccharomyces cerevisiae attractive targets for the engineering of methylotrophic metabolism. S. cerevisiae strains S288C and CEN.PK are the two best-characterised and most widely used hosts for yeast synthetic biology and metabolic engineering, yet they have unpredictable metabolic phenotypes related to their many genomic differences. We therefore sought to benchmark these two strains as potential hosts for engineered methylotrophic metabolism by comparing their growth and transcriptomic responses to methanol. CEN.PK had improved growth in the presence of methanol relative to the S288C derivative BY4741. The CEN.PK transcriptome also had a specific and relevant response to methanol that was either absent or less pronounced in the BY4741 strain. This response included up-regulation of genes associated with mitochondrial and peroxisomal metabolism, alcohol and formate dehydrogenation, glutathione metabolism, and the global transcriptional regulator of metabolism MIG3. Over-expression of MIG3 enabled improved growth in the presence of methanol, suggesting that MIG3 is a mediator of the superior CEN.PK strain growth. CEN.PK was therefore identified as a superior strain for the future development of synthetic methylotrophy in S. cerevisiae.
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Affiliation(s)
- Monica I. Espinosa
- ARC Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, NSW, Australia
- CSIRO Synthetic Biology Future Science Platform, Canberra, ACT, 2601, Australia
| | - Thomas C. Williams
- ARC Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, NSW, Australia
- CSIRO Synthetic Biology Future Science Platform, Canberra, ACT, 2601, Australia
| | - Isak S. Pretorius
- ARC Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, NSW, Australia
| | - Ian T. Paulsen
- ARC Centre of Excellence in Synthetic Biology, Department of Molecular Sciences, Macquarie University, NSW, Australia
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Sánchez-Gaya V, Casaní-Galdón S, Ugidos M, Kuang Z, Mellor J, Conesa A, Tarazona S. Elucidating the Role of Chromatin State and Transcription Factors on the Regulation of the Yeast Metabolic Cycle: A Multi-Omic Integrative Approach. Front Genet 2018; 9:578. [PMID: 30555512 PMCID: PMC6284056 DOI: 10.3389/fgene.2018.00578] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/08/2018] [Indexed: 11/15/2022] Open
Abstract
The Yeast Metabolic Cycle (YMC) is a model system in which levels of around 60% of the yeast transcripts cycle over time. The spatial and temporal resolution provided by the YMC has revealed that changes in the yeast metabolic landscape and chromatin status can be related to cycling gene expression. However, the interplay between histone modifications and transcription factor activity during the YMC is still poorly understood. Here we apply an innovative statistical approach to integrate chromatin state (ChIP-seq) and gene expression (RNA-seq) data to investigate the transcriptional control during the YMC. By using the multivariate regression models N-PLS (Partial Least Squares) and MORE (Multi-Omics REgulation) methodologies, we assessed the contribution of histone marks and transcription factors to the regulation of gene expression in the YMC. We found that H3K18ac and H3K9ac were the most important histone modifications, whereas Sfp1, Hfi1, Pip2, Mig2, and Yhp1 emerged as the most relevant transcription factors. A significant association in the co-regulation of gene expression was found between H3K18ac and the transcription factors Pip2 (involved in fatty acids metabolism), Xbp1 (cyclin implicated in the regulation of carbohydrate and amino acid metabolism), and Hfi1 (involved in the formation of the SAGA complex). These results evidence the crucial role of histone lysine acetylation levels in the regulation of gene expression in the YMC through the coordinated action of transcription factors and lysine acetyltransferases.
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Affiliation(s)
- Víctor Sánchez-Gaya
- Genomics of Gene Expression Laboratory Centro de Investigación Príncipe Felipe, Valencia, Spain
| | | | - Manuel Ugidos
- Genomics of Gene Expression Laboratory Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Zheng Kuang
- Institute for Systems Genetics, NYU Langone Health, New York, NY, United States
| | - Jane Mellor
- Department of Biochemistry University of Oxford, Oxford, United Kingdom
| | - Ana Conesa
- BioBam Bioinformatics S.L., Valencia, Spain.,Microbiology and Cell Science Department, Institute for Food and Agricultural Research, University of Florida, Gainesville, FL, United States.,Genetics Institute, University of Florida, Gainesville, FL, United States
| | - Sonia Tarazona
- Genomics of Gene Expression Laboratory Centro de Investigación Príncipe Felipe, Valencia, Spain.,Applied Statistics, Operational Research and Quality Department Polytechnic University of Valencia, Valencia, Spain
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6
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Muniswamy V, Bangalore Muniraju C, Kumar Pattnaik P, Krishnaswamy N. Modeling and Analysis of an Opto-Fluidic Sensor for Lab-on-a-Chip Applications. MICROMACHINES 2018; 9:mi9030134. [PMID: 30424068 PMCID: PMC6187541 DOI: 10.3390/mi9030134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/15/2018] [Accepted: 03/15/2018] [Indexed: 11/16/2022]
Abstract
In this work modeling and analysis of an integrated opto-fluidic sensor, with a focus on achievement of single mode optical confinement and continuous flow of microparticles in the microfluidic channel for lab-on-a-chip (LOC) sensing application is presented. This sensor consists of integrated optical waveguides, microfluidic channel among other integrated optical components. A continuous flow of microparticles in a narrow fluidic channel is achieved by maintaining the two sealed chambers at different temperatures and by maintaining a constant pressure of 1 Pa at the centroid of narrow fluidic channel geometry. The analysis of silicon on insulator (SOI) integrated optical waveguide at an infrared wavelength of 1550 nm for single mode sensing operation is presented. The optical loss is found to be 5.7 × 10-4 dB/cm with an effective index of 2.3. The model presented in this work can be effectively used to detect the nature of microparticles and continuous monitoring of pathological parameters for sensing applications.
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Affiliation(s)
- Venkatesha Muniswamy
- Department of Electronics and Communication Engineering, Sai Vidya Institute of Technology, Bengaluru, Karnataka 560064, India.
| | - Chaya Bangalore Muniraju
- Department of Electronics and Communication Engineering, Sai Vidya Institute of Technology, Bengaluru, Karnataka 560064, India.
| | - Prasant Kumar Pattnaik
- Department of Electrical Engineering, BITS-Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India.
| | - Narayan Krishnaswamy
- Department of Electronics and Communication Engineering, Sai Vidya Institute of Technology, Bengaluru, Karnataka 560064, India.
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Mirallas O, Ballega E, Samper-Martín B, García-Márquez S, Carballar R, Ricco N, Jiménez J, Clotet J. Intertwined control of the cell cycle and nucleocytoplasmic transport by the cyclin-dependent kinase Pho85 and RanGTPase Gsp1 in Saccharomyces cerevisiae. Microbiol Res 2017; 206:168-176. [PMID: 29146254 DOI: 10.1016/j.micres.2017.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/09/2017] [Accepted: 10/17/2017] [Indexed: 10/18/2022]
Abstract
Deciphering the molecular mechanisms that connect cell cycle progression and nucleocytoplasmic transport is of particular interest: this intertwined relationship, once understood, may provide useful insight on the diseases resulting from the malfunction of these processes. In the present study we report on findings that indicate a biochemical connection between the cell cycle regulator CDK Pho85 and Ran-GTPase Gsp1, an essential nucleocytoplasmic transport component. When Gsp1 cannot be phosphorylated by Pho85, the cell cycle progression is impaired. Accordingly, a nonphosphorylatable version of Gsp1 abnormally localizes to the nucleus, which impairs the nuclear transport of molecules, including key components of cell cycle progression. Furthermore, our results suggest that the physical interaction of Gsp1 and the Kap95 karyopherin, essential to the release of nuclear cargoes, is altered. Altogether, the present findings point to the involvement of a biochemical mechanism in the interlocked regulation of the cell cycle and nuclear transport.
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Affiliation(s)
- Oriol Mirallas
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Elisabet Ballega
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Bàrbara Samper-Martín
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Sergio García-Márquez
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Reyes Carballar
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Natalia Ricco
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Javier Jiménez
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
| | - Josep Clotet
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
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Gagnon J, Lavoie M, Catala M, Malenfant F, Elela SA. Transcriptome wide annotation of eukaryotic RNase III reactivity and degradation signals. PLoS Genet 2015; 11:e1005000. [PMID: 25680180 PMCID: PMC4334505 DOI: 10.1371/journal.pgen.1005000] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 01/13/2015] [Indexed: 12/11/2022] Open
Abstract
Detection and validation of the RNA degradation signals controlling transcriptome stability are essential steps for understanding how cells regulate gene expression. Here we present complete genomic and biochemical annotations of the signals required for RNA degradation by the dsRNA specific ribonuclease III (Rnt1p) and examine its impact on transcriptome expression. Rnt1p cleavage signals are randomly distributed in the yeast genome, and encompass a wide variety of sequences, indicating that transcriptome stability is not determined by the recurrence of a fixed cleavage motif. Instead, RNA reactivity is defined by the sequence and structural context in which the cleavage sites are located. Reactive signals are often associated with transiently expressed genes, and their impact on RNA expression is linked to growth conditions. Together, the data suggest that Rnt1p reactivity is triggered by malleable RNA degradation signals that permit dynamic response to changes in growth conditions. RNA degradation is essential for gene regulation. The amount and timing of protein synthesis is determined, at least in part, by messenger RNA stability. Although RNA stability is determined by specific structural and sequence motif, the distribution of the degradation signals in eukaryotic genomes remains unclear. In this study, we describe the genomic distribution of the RNA degradation signals required for selective nuclear degradation in yeast. The results indicate that most RNAs in the yeast transcriptome are predisposed for degradation, but only few are catalytically active. The catalytic reactivity of messenger RNAs were mostly determined by the overall structural context of the degradation signals. Strikingly, most active RNA degradation signals are found in genes associated with respiration and fermentation. Overall, the findings reported here demonstrate how certain RNA are selected for cleavage and illustrated the importance of this selective RNA degradation for fine tuning gene expression in response to changes in growth condition.
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Affiliation(s)
- Jules Gagnon
- Université de Sherbrooke Centre of Excellence in RNA Biology, Département de microbiologie et d’infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Mathieu Lavoie
- Université de Sherbrooke Centre of Excellence in RNA Biology, Département de microbiologie et d’infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Mathieu Catala
- Université de Sherbrooke Centre of Excellence in RNA Biology, Département de microbiologie et d’infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Francis Malenfant
- Université de Sherbrooke Centre of Excellence in RNA Biology, Département de microbiologie et d’infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Sherif Abou Elela
- Université de Sherbrooke Centre of Excellence in RNA Biology, Département de microbiologie et d’infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
- * E-mail:
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Yao Y, Tsuchiyama S, Yang C, Bulteau AL, He C, Robison B, Tsuchiya M, Miller D, Briones V, Tar K, Potrero A, Friguet B, Kennedy BK, Schmidt M. Proteasomes, Sir2, and Hxk2 form an interconnected aging network that impinges on the AMPK/Snf1-regulated transcriptional repressor Mig1. PLoS Genet 2015; 11:e1004968. [PMID: 25629410 PMCID: PMC4309596 DOI: 10.1371/journal.pgen.1004968] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 12/19/2014] [Indexed: 01/20/2023] Open
Abstract
Elevated proteasome activity extends lifespan in model organisms such as yeast, worms and flies. This pro-longevity effect might be mediated by improved protein homeostasis, as this protease is an integral module of the protein homeostasis network. Proteasomes also regulate cellular processes through temporal and spatial degradation of signaling pathway components. Here we demonstrate that the regulatory function of the proteasome plays an essential role in aging cells and that the beneficial impact of elevated proteasome capacity on lifespan partially originates from deregulation of the AMPK signaling pathway. Proteasome-mediated lifespan extension activity was carbon-source dependent and cells with enhancement proteasome function exhibited increased respiratory activity and oxidative stress response. These findings suggested that the pro-aging impact of proteasome upregulation might be related to changes in the metabolic state through a premature induction of respiration. Deletion of yeast AMPK, SNF1, or its activator SNF4 abrogated proteasome-mediated lifespan extension, supporting this hypothesis as the AMPK pathway regulates metabolism. We found that the premature induction of respiration in cells with increased proteasome activity originates from enhanced turnover of Mig1, an AMPK/Snf1 regulated transcriptional repressor that prevents the induction of genes required for respiration. Increasing proteasome activity also resulted in partial relocation of Mig1 from the nucleus to the mitochondria. Collectively, the results argue for a model in which elevated proteasome activity leads to the uncoupling of Snf1-mediated Mig1 regulation, resulting in a premature activation of respiration and thus the induction of a mitohormetic response, beneficial to lifespan. In addition, we observed incorrect Mig1 localization in two other long-lived yeast aging models: cells that overexpress SIR2 or deleted for the Mig1-regulator HXK2. Finally, compromised proteasome function blocks lifespan extension in both strains. Thus, our findings suggest that proteasomes, Sir2, Snf1 and Hxk2 form an interconnected aging network that controls metabolism through coordinated regulation of Mig1. Advanced cellular age is associated with decreased efficiency of the proteostasis network. The proteasome, a protease in the cytoplasm and nuclei of eukaryotic cells, is an important component of this network. Recent studies demonstrate that increased proteasome capacity has a positive impact on longevity. The underlying mechanisms, however, have not been fully identified. Here we report that proteasomes are involved in regulating the AMP-activated kinase (AMPK) pathway and thus participate in correct metabolic adaptation. We find that Mig1, a transcriptional repressor downstream of yeast AMPK, Snf1, is a proteasome target and a negative regulator of lifespan. Increased proteasome activity results in enhanced turnover and incorrect localization of Mig1. The reduced Mig1 levels result in the induction of respiration and upregulation of the oxidative stress response. Premature Mig1 inactivation is also observed in two additional long-lived strains that overexpress SIR2 or are deleted for HXK2 and lifespan extension in both strains requires correct proteasome function. Our results uncover an interconnected network comprised of the proteasome, Sir2 and AMPK/Hxk2 signaling that impacts longevity through regulation of Mig1 and modulates respiratory metabolism. Mechanistic information on the cross-communication between these pathways is expected to facilitate the identification of novel pro-aging interventions.
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Affiliation(s)
- Yanhua Yao
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | | | - Ciyu Yang
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | | | - Chong He
- Buck Institute, Novato, California, United States of America
| | - Brett Robison
- Buck Institute, Novato, California, United States of America
| | | | - Delana Miller
- Buck Institute, Novato, California, United States of America
| | - Valeria Briones
- Buck Institute, Novato, California, United States of America
| | - Krisztina Tar
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Anahi Potrero
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Bertrand Friguet
- Laboratoire de Biologie Cellulaire du Vieillissement, UR4-IFR83, Université Pierre et Marie Curie-Paris 6, Paris, France
| | - Brian K. Kennedy
- Buck Institute, Novato, California, United States of America
- * E-mail: (MS); (BKK)
| | - Marion Schmidt
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
- * E-mail: (MS); (BKK)
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Bauer NC, Corbett AH, Doetsch PW. Automated quantification of the subcellular localization of multicompartment proteins via Q-SCAn. Traffic 2013; 14:1200-8. [PMID: 24034606 PMCID: PMC3836439 DOI: 10.1111/tra.12118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 09/06/2013] [Accepted: 09/11/2013] [Indexed: 01/19/2023]
Abstract
In eukaryotic cells, proteins can occupy multiple intracellular compartments and even move between compartments to fulfill critical biological functions or respond to cellular signals. Examples include transcription factors that reside in the cytoplasm but are mobilized to the nucleus as well as dual-purpose DNA repair proteins that are charged with simultaneously maintaining the integrity of both the nuclear and mitochondrial genomes. While numerous methods exist to study protein localization and dynamics, automated methods to quantify the relative amounts of proteins that occupy multiple subcellular compartments have not been extensively developed. To address this need, we present a rapid, automated method termed quantitative subcellular compartmentalization analysis (Q-SCAn). To develop this method, we exploited the facile molecular biology of the budding yeast, Saccharomyces cerevisiae. Individual subcellular compartments are defined by a fluorescent marker protein and the intensity of a target GFP-tagged protein is then quantified within each compartment. To validate Q-SCAn, we analyzed relocalization of the transcription factor Yap1 following oxidative stress and then extended the approach to multicompartment localization by examining two DNA repair proteins critical for the base excision repair pathway, Ntg1 and Ung1. Our findings demonstrate the utility of Q-SCAn for quantitative analysis of the subcellular distribution of multicompartment proteins.
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Affiliation(s)
- Nicholas C. Bauer
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Anita H. Corbett
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, United States
| | - Paul W. Doetsch
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, United States
- Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA, 30322, United States
- Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA, 30322, United States
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Fernández-Cid A, Vega M, Herrero P, Moreno F. Yeast importin-β is required for nuclear import of the Mig2 repressor. BMC Cell Biol 2012; 13:31. [PMID: 23131016 PMCID: PMC3531251 DOI: 10.1186/1471-2121-13-31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 11/04/2012] [Indexed: 12/25/2022] Open
Abstract
Background Mig2 has been described as a transcriptional factor that in the absence of Mig1 protein is required for glucose repression of the SUC2 gene. Recently it has been reported that Mig2 has two different subcellular localizations. In high-glucose conditions it is a nuclear modulator of several Mig1-regulated genes, but in low-glucose most of the Mig2 protein accumulates in mitochondria. Thus, the Mig2 protein enters and leaves the nucleus in a glucose regulated manner. However, the mechanism by which Mig2 enters into the nucleus was unknown until now. Results Here, we report that the Mig2 protein is an import substrate of the carrier Kap95 (importin-β). The Mig2 nuclear import mechanism bypasses the requirement for Kap60 (importin-α) as an adaptor protein, since Mig2 directly binds to Kap95 in the presence of Gsp1(GDP). We also show that the Mig2 nuclear import and the binding of Mig2 with Kap95 are not glucose-dependent processes and require a basic NLS motif, located between lysine-32 and arginine-37. Mig2 interaction with Kap95 was assessed in vitro using purified proteins, demonstrating that importin-β, together with the GTP-binding protein Gsp1, is able to mediate efficient Mig2-Kap95 interaction in the absence of the importin-α (Kap60). It was also demonstrated, that the directionality of Mig2 transport is regulated by association with the small GTPase Gsp1 in the GDP- or GTP-bound forms, which promote cargo recognition and release, respectively. Conclusions The Mig2 protein accumulates in the nucleus through a Kap95 and NLS-dependent nuclear import pathway, which is independent of importin-α in Saccharomyces cerevisiae.
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Affiliation(s)
- Alejandra Fernández-Cid
- Department of Biochemistry and Molecular Biology, University of Oviedo, 33006, Oviedo, Spain
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The filamentous growth MAPK Pathway Responds to Glucose Starvation Through the Mig1/2 transcriptional repressors in Saccharomyces cerevisiae. Genetics 2012; 192:869-87. [PMID: 22904036 DOI: 10.1534/genetics.112.142661] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In the budding yeast S. cerevisiae, nutrient limitation induces a MAPK pathway that regulates filamentous growth and biofilm/mat formation. How nutrient levels feed into the regulation of the filamentous growth pathway is not entirely clear. We characterized a newly identified MAPK regulatory protein of the filamentous growth pathway, Opy2. A two-hybrid screen with the cytosolic domain of Opy2 uncovered new interacting partners including a transcriptional repressor that functions in the AMPK pathway, Mig1, and its close functional homolog, Mig2. Mig1 and Mig2 coregulated the filamentous growth pathway in response to glucose limitation, as did the AMP kinase Snf1. In addition to associating with Opy2, Mig1 and Mig2 interacted with other regulators of the filamentous growth pathway including the cytosolic domain of the signaling mucin Msb2, the MAP kinase kinase Ste7, and the MAP kinase Kss1. As for Opy2, Mig1 overproduction dampened the pheromone response pathway, which implicates Mig1 and Opy2 as potential regulators of pathway specificity. Taken together, our findings provide the first regulatory link in yeast between components of the AMPK pathway and a MAPK pathway that controls cellular differentiation.
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