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Li G, Cao X, Tumukunde E, Zeng Q, Wang S. The target of rapamycin signaling pathway regulates vegetative development, aflatoxin biosynthesis, and pathogenicity in Aspergillus flavus. eLife 2024; 12:RP89478. [PMID: 38990939 PMCID: PMC11239180 DOI: 10.7554/elife.89478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Abstract
The target of rapamycin (TOR) signaling pathway is highly conserved and plays a crucial role in diverse biological processes in eukaryotes. Despite its significance, the underlying mechanism of the TOR pathway in Aspergillus flavus remains elusive. In this study, we comprehensively analyzed the TOR signaling pathway in A. flavus by identifying and characterizing nine genes that encode distinct components of this pathway. The FK506-binding protein Fkbp3 and its lysine succinylation are important for aflatoxin production and rapamycin resistance. The TorA kinase plays a pivotal role in the regulation of growth, spore production, aflatoxin biosynthesis, and responses to rapamycin and cell membrane stress. As a significant downstream effector molecule of the TorA kinase, the Sch9 kinase regulates aflatoxin B1 (AFB1) synthesis, osmotic and calcium stress response in A. flavus, and this regulation is mediated through its S_TKc, S_TK_X domains, and the ATP-binding site at K340. We also showed that the Sch9 kinase may have a regulatory impact on the high osmolarity glycerol (HOG) signaling pathway. TapA and TipA, the other downstream components of the TorA kinase, play a significant role in regulating cell wall stress response in A. flavus. Moreover, the members of the TapA-phosphatase complexes, SitA and Ppg1, are important for various biological processes in A. flavus, including vegetative growth, sclerotia formation, AFB1 biosynthesis, and pathogenicity. We also demonstrated that SitA and Ppg1 are involved in regulating lipid droplets (LDs) biogenesis and cell wall integrity (CWI) signaling pathways. In addition, another phosphatase complex, Nem1/Spo7, plays critical roles in hyphal development, conidiation, aflatoxin production, and LDs biogenesis. Collectively, our study has provided important insight into the regulatory network of the TOR signaling pathway and has elucidated the underlying molecular mechanisms of aflatoxin biosynthesis in A. flavus.
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Affiliation(s)
- Guoqi Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Pathogenic, Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhouChina
| | - Xiaohong Cao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Pathogenic, Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhouChina
| | - Elisabeth Tumukunde
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Pathogenic, Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhouChina
| | - Qianhua Zeng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Pathogenic, Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhouChina
| | - Shihua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Pathogenic, Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhouChina
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Chen Y, Gao S, Zhou J, Zeng W. Chromatin regulator Eaf3p regulates nitrogen metabolism in Saccharomyces cerevisiae as a trans-acting factor. Appl Environ Microbiol 2023; 89:e0145723. [PMID: 38047643 PMCID: PMC10734424 DOI: 10.1128/aem.01457-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 10/23/2023] [Indexed: 12/05/2023] Open
Abstract
IMPORTANCE In this study, the mechanism of chromatin regulator Eaf3p regulating nitrogen metabolism in S. cerevisiae was investigated. It provides theoretical support for epigenetic modifications of cells to alter the level of histone modifications, coordinate the expression of multiple genes, and make it more conducive to the co-metabolism of multiple nitrogen sources. Moreover, it provides new ideas for industrial brewing yeast strains to achieve nitrogen source metabolism balance, reduce the accumulation of harmful nitrogen metabolites, and improve fermentation efficiency. This study provides a reference for changing the performance of microbial strains and improving the quality of traditional fermentation products and provides a theoretical basis for studying epigenetic modification and nitrogen metabolism regulation. It has an important theoretical explanation and practical application value. In addition, this study also provides useful clues for the study.
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Affiliation(s)
- Yu Chen
- College of Biological and Food Engineering, Anhui Polytechnic University, Wuhu, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
- Science Center for Future Foods, Jiangnan University, Wuxi, China
| | - Song Gao
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
- Science Center for Future Foods, Jiangnan University, Wuxi, China
| | - Jingwen Zhou
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
- Science Center for Future Foods, Jiangnan University, Wuxi, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Weizhu Zeng
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
- Science Center for Future Foods, Jiangnan University, Wuxi, China
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Acs-Szabo L, Papp LA, Takacs S, Miklos I. Disruption of the Schizosaccharomyces japonicus lig4 Disturbs Several Cellular Processes and Leads to a Pleiotropic Phenotype. J Fungi (Basel) 2023; 9:jof9050550. [PMID: 37233261 DOI: 10.3390/jof9050550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/15/2023] [Accepted: 05/05/2023] [Indexed: 05/27/2023] Open
Abstract
Gene targeting is a commonly used method to reveal the function of genes. Although it is an attractive tool for molecular studies, it can frequently be a challenge because its efficiency can be low and it requires the screening of a large number of transformants. Generally, these problems originate from the elevated level of ectopic integration caused by non-homologous DNA end joining (NHEJ). To eliminate this problem, NHEJ-related genes are frequently deleted or disrupted. Although these manipulations can improve gene targeting, the phenotype of the mutant strains raised the question of whether mutations have side effects. The aim of this study was to disrupt the lig4 gene in the dimorphic fission yeast, S. japonicus, and investigate the phenotypic changes of the mutant strain. The mutant cells have shown various phenotypic changes, such as increased sporulation on complete medium, decreased hyphal growth, faster chronological aging, and higher sensitivity to heat shock, UV light, and caffeine. In addition, higher flocculation capacity has been observed, especially at lower sugar concentrations. These changes were supported by transcriptional profiling. Many genes belonging to metabolic and transport processes, cell division, or signaling had altered mRNA levels compared to the control strain. Although the disruption improved the gene targeting, we assume that the lig4 inactivation can cause unexpected physiological side effects, and we have to be very careful with the manipulations of the NHEJ-related genes. To reveal the exact mechanisms behind these changes, further investigations are required.
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Affiliation(s)
- Lajos Acs-Szabo
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Laszlo Attila Papp
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Szonja Takacs
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Ida Miklos
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
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Cysteine Inhibits the Growth of Fusarium oxysporum and Promotes T-2 Toxin Synthesis through the Gtr/Tap42 Pathway. Microbiol Spectr 2022; 10:e0368222. [PMID: 36314982 PMCID: PMC9769839 DOI: 10.1128/spectrum.03682-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Fusarium oxysporum is ubiquitous and can easily contaminate food during processing and storage, potentially producing T-2 toxin, which can pose a severe health risk to public health. Previous research on the presence of T-2 has focused on starch-rich foods, while protein- and amino acid-rich foods have received relatively little attention. In this study, the effects of amino acids on the growth of F. oxysporum and its T-2 production were investigated by gene deletion and complementation experiments. The results showed that amino acids, including aspartic acid, methionine, isoleucine, serine, phenylalanine, and cysteine, significantly inhibited the growth of F. oxysporum, while promoting T-2 synthesis, with cysteine having the most pronounced effect. The target of rapamycin complex 1 (TORC1) is a key pathway in response to a variety of amino acids, including cysteine. gtr2 and tap42 were found to be negative regulators of T-2 synthesis. The study highlights the elevated risk of T-2 production by F. oxysporum in cysteine-rich foods and the need to take appropriate measures to prevent and control the potential harm that such foods may present to public health. IMPORTANCE F. oxysporum and its T-2 contamination of food not only leads to food wastage but also poses a major food safety challenge to humans. The growth and T-2 production characteristics of F. oxysporum in high-protein substrates are considerably different from those in grains. Here, we show that the abundant free amino acids in a protein-rich food matrix are a key regulatory factor for the growth of, and toxin production by, F. oxysporum. Cysteine has the most pronounced effect on inhibiting mycelial growth and promoting T-2 synthesis through the TORC1 pathway. This implies that consumers tend to overlook T-2 contamination due to the poor growth of F. oxysporum in food rich in protein and amino acids, especially cysteine. Therefore, particular attention should be paid to the protection of those products.
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Yaseen I, White SA, Torres-Garcia S, Spanos C, Lafos M, Gaberdiel E, Yeboah R, El Karoui M, Rappsilber J, Pidoux AL, Allshire RC. Proteasome-dependent truncation of the negative heterochromatin regulator Epe1 mediates antifungal resistance. Nat Struct Mol Biol 2022; 29:745-758. [PMID: 35879419 PMCID: PMC7613290 DOI: 10.1038/s41594-022-00801-y] [Citation(s) in RCA: 8] [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: 11/26/2021] [Accepted: 06/06/2022] [Indexed: 12/03/2022]
Abstract
Epe1 histone demethylase restricts H3K9-methylation-dependent heterochromatin, preventing it from spreading over, and silencing, gene-containing regions in fission yeast. External stress induces an adaptive response allowing heterochromatin island formation that confers resistance on surviving wild-type lineages. Here we investigate the mechanism by which Epe1 is regulated in response to stress. Exposure to caffeine or antifungals results in Epe1 ubiquitylation and proteasome-dependent removal of the N-terminal 150 residues from Epe1, generating truncated Epe1 (tEpe1) which accumulates in the cytoplasm. Constitutive tEpe1 expression increases H3K9 methylation over several chromosomal regions, reducing expression of underlying genes and enhancing resistance. Reciprocally, constitutive non-cleavable Epe1 expression decreases resistance. tEpe1-mediated resistance requires a functional JmjC demethylase domain. Moreover, caffeine-induced Epe1-to-tEpe1 cleavage is dependent on an intact cell integrity MAP kinase stress signaling pathway, mutations in which alter resistance. Thus, environmental changes elicit a mechanism that curtails the function of this key epigenetic modifier, allowing heterochromatin to reprogram gene expression, thereby bestowing resistance to some cells within a population. H3K9me-heterochromatin components are conserved in human and crop-plant fungal pathogens for which a limited number of antifungals exist. Our findings reveal how transient heterochromatin-dependent antifungal resistant epimutations develop and thus inform on how they might be countered.
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Affiliation(s)
- Imtiyaz Yaseen
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- CSIR Indian Institute of Integrative Medicine, Jammu, India
| | - Sharon A White
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
| | - Sito Torres-Garcia
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
| | - Christos Spanos
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
| | - Marcel Lafos
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- School of Life Sciences, University of Dundee, Dundee, UK
| | - Elisabeth Gaberdiel
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
| | - Rebecca Yeboah
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
| | - Meriem El Karoui
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- SynthSys, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
| | - Juri Rappsilber
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Alison L Pidoux
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
| | - Robin C Allshire
- Wellcome Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK.
- Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK.
- SynthSys, School of Biological Sciences, The University of Edinburgh, Edinburgh, UK.
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Haq SIU, Shang J, Xie H, Qiu QS. Roles of TOR signaling in nutrient deprivation and abiotic stress. JOURNAL OF PLANT PHYSIOLOGY 2022; 274:153716. [PMID: 35597106 DOI: 10.1016/j.jplph.2022.153716] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/25/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
In living organisms, nutrient, energy, and environmental stimuli sensing and signaling are considered as the most primordial regulatory networks governing growth and development. Target of Rapamycin (TOR) is a diversified Serine/Threonine protein kinase existing in all eukaryotes that regulates distinct salient growth and developmental signaling pathways. TOR signaling acts as a central hub in plants that allows a variety of nutrients, energy, hormones, and environmental stimuli to be integrated. TOR is activated by several nutrients and promotes energy-consuming processes such as cell division, protein translation, mRNA translation and ribosome biogenesis. We summarized the recent findings on the TOR function in regulating the dynamic networks of nutrients, including sugar, sulfur, nitrogen, carbon, phosphorus, potassium, and amino acids. TOR's role in abiotic stress was discussed, in which TOR orchestrating stress signaling, including heat, cold, salt, and osmotic stress, to regulate transcriptional and metabolic reprogramming, as well as growth and development. The interconnections between TOR and SnRK1 kinase were discussed in controlling nutrient deprivation and abiotic stress.
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Affiliation(s)
- Syed Inzimam Ul Haq
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China
| | - Jun Shang
- Academy of Plateau Science and Sustainability, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, 810000, China; Qinghai Provincial Key Laboratory of Medicinal Plant and Animal Resources of Qinghai-Tibet Plateau, Xining, Qinghai, 810008, China
| | - Huichun Xie
- Academy of Plateau Science and Sustainability, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, 810000, China; Qinghai Provincial Key Laboratory of Medicinal Plant and Animal Resources of Qinghai-Tibet Plateau, Xining, Qinghai, 810008, China
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China; Academy of Plateau Science and Sustainability, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, 810000, China.
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Stress- and metabolic responses of Candida albicans require Tor1 kinase N-terminal HEAT repeats. PLoS Pathog 2022; 18:e1010089. [PMID: 35687592 PMCID: PMC9223334 DOI: 10.1371/journal.ppat.1010089] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 06/23/2022] [Accepted: 05/12/2022] [Indexed: 11/19/2022] Open
Abstract
Whether to commit limited cellular resources toward growth and proliferation, or toward survival and stress responses, is an essential determination made by Target of Rapamycin Complex 1 (TORC1) for a eukaryotic cell in response to favorable or adverse conditions. Loss of TORC1 function is lethal. The TORC1 inhibitor rapamycin that targets the highly conserved Tor kinase domain kills fungal pathogens like Candida albicans, but is also severely toxic to human cells. The least conserved region of fungal and human Tor kinases are the N-terminal HEAT domains. We examined the role of the 8 most N-terminal HEAT repeats of C. albicans Tor1. We compared nutritional- and stress responses of cells that express a message for N-terminally truncated Tor1 from repressible tetO, with cells expressing wild type TOR1 from tetO or from the native promoter. Some but not all stress responses were significantly impaired by loss of Tor1 N-terminal HEAT repeats, including those to oxidative-, cell wall-, and heat stress; in contrast, plasma membrane stress and antifungal agents that disrupt plasma membrane function were tolerated by cells lacking this Tor1 region. Translation was inappropriately upregulated during oxidative stress in cells lacking N-terminal Tor1 HEAT repeats despite simultaneously elevated Gcn2 activity, while activation of the oxidative stress response MAP kinase Hog1 was weak. Conversely, these cells were unable to take advantage of favorable nutritional conditions by accelerating their growth. Consuming oxygen more slowly than cells containing wild type TOR1 alleles during growth in glucose, cells lacking N-terminal Tor1 HEAT repeats additionally were incapable of utilizing non-fermentable carbon sources. They were also hypersensitive to inhibitors of specific complexes within the respiratory electron transport chain, suggesting that inefficient ATP generation and a resulting dearth of nucleotide sugar building blocks for cell wall polysaccharides causes cell wall integrity defects in these mutants. Genome-wide expression analysis of cells lacking N-terminal HEAT repeats showed dysregulation of carbon metabolism, cell wall biosynthetic enzymes, translational machinery biosynthesis, oxidative stress responses, and hyphal- as well as white-opaque cell type-associated genes. Targeting fungal-specific Tor1 N-terminal HEAT repeats with small molecules might selectively abrogate fungal viability, especially when during infection multiple stresses are imposed by the host immune system. Whether growing harmlessly on our mucous membranes in competition with bacterial multitudes, or invading our tissues and bloodstream, the fungus Candida albicans must be capable of rapid growth when it finds abundant nutrients and favorable conditions. It must also be able to switch to stress- and survival mode when encountering host immune cells and when starving for nutrients. Tor1 kinase is the central regulator at the heart of these cellular decisions. As an essential protein, it is an attractive drug target. But the Tor1 kinase domain is very similar to its human counterpart, rendering its inhibitors like rapamycin toxic for humans. We identified a region of helical protein-protein interaction domains, the N-terminal HEAT repeats, as the least conserved part of C. albicans Tor1. Using genetic- and genome-wide expression analysis, we found that 8 N-terminal HEAT repeats are required for growth acceleration in nutrient-rich environments and for decreased translation in starvation- and stress conditions. This Tor1 region contributes to oxidative-, cell wall- and heat stress reponses, to hyphal growth and to respiration, but apparently not to plasma membrane stress endurance or fermentation. Small molecules that disrupt the protein-protein interactions mediated by this region could become fungal-selective inhibitors of Tor kinase.
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Kleijn IT, Martínez-Segura A, Bertaux F, Saint M, Kramer H, Shahrezaei V, Marguerat S. Growth-rate-dependent and nutrient-specific gene expression resource allocation in fission yeast. Life Sci Alliance 2022; 5:e202101223. [PMID: 35228260 PMCID: PMC8886410 DOI: 10.26508/lsa.202101223] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 01/25/2022] [Accepted: 01/25/2022] [Indexed: 12/20/2022] Open
Abstract
Cellular resources are limited and their relative allocation to gene expression programmes determines physiological states and global properties such as the growth rate. Here, we determined the importance of the growth rate in explaining relative changes in protein and mRNA levels in the simple eukaryote Schizosaccharomyces pombe grown on non-limiting nitrogen sources. Although expression of half of fission yeast genes was significantly correlated with the growth rate, this came alongside wide-spread nutrient-specific regulation. Proteome and transcriptome often showed coordinated regulation but with notable exceptions, such as metabolic enzymes. Genes positively correlated with growth rate participated in every level of protein production apart from RNA polymerase II-dependent transcription. Negatively correlated genes belonged mainly to the environmental stress response programme. Critically, metabolic enzymes, which represent ∼55-70% of the proteome by mass, showed mostly condition-specific regulation. In summary, we provide a rich account of resource allocation to gene expression in a simple eukaryote, advancing our basic understanding of the interplay between growth-rate-dependent and nutrient-specific gene expression.
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Affiliation(s)
- Istvan T Kleijn
- Medical Research Council London Institute of Medical Sciences (MRC LMS), London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
- Department of Mathematics, Faculty of Natural Sciences, Imperial College London, London, UK
| | - Amalia Martínez-Segura
- Medical Research Council London Institute of Medical Sciences (MRC LMS), London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
| | - François Bertaux
- Medical Research Council London Institute of Medical Sciences (MRC LMS), London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
- Department of Mathematics, Faculty of Natural Sciences, Imperial College London, London, UK
| | - Malika Saint
- Medical Research Council London Institute of Medical Sciences (MRC LMS), London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
| | - Holger Kramer
- Medical Research Council London Institute of Medical Sciences (MRC LMS), London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
| | - Vahid Shahrezaei
- Department of Mathematics, Faculty of Natural Sciences, Imperial College London, London, UK
| | - Samuel Marguerat
- Medical Research Council London Institute of Medical Sciences (MRC LMS), London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
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Segreto R, Bazafkan H, Millinger J, Schenk M, Atanasova L, Doppler M, Büschl C, Boeckstaens M, Soto Diaz S, Schreiner U, Sillo F, Balestrini R, Schuhmacher R, Zeilinger S. The TOR kinase pathway is relevant for nitrogen signaling and antagonism of the mycoparasite Trichoderma atroviride. PLoS One 2022; 16:e0262180. [PMID: 34972198 PMCID: PMC8719763 DOI: 10.1371/journal.pone.0262180] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 12/18/2021] [Indexed: 01/14/2023] Open
Abstract
Trichoderma atroviride (Ascomycota, Sordariomycetes) is a well-known mycoparasite applied for protecting plants against fungal pathogens. Its mycoparasitic activity involves processes shared with plant and human pathogenic fungi such as the production of cell wall degrading enzymes and secondary metabolites and is tightly regulated by environmental cues. In eukaryotes, the conserved Target of Rapamycin (TOR) kinase serves as a central regulator of cellular growth in response to nutrient availability. Here we describe how alteration of the activity of TOR1, the single and essential TOR kinase of T. atroviride, by treatment with chemical TOR inhibitors or by genetic manipulation of selected TOR pathway components affected various cellular functions. Loss of TSC1 and TSC2, that are negative regulators of TOR complex 1 (TORC1) in mammalian cells, resulted in altered nitrogen source-dependent growth of T. atroviride, reduced mycoparasitic overgrowth and, in the case of Δtsc1, a diminished production of numerous secondary metabolites. Deletion of the gene encoding the GTPase RHE2, whose mammalian orthologue activates mTORC1, led to rapamycin hypersensitivity and altered secondary metabolism, but had an only minor effect on vegetative growth and mycoparasitic overgrowth. The latter also applied to mutants missing the npr1-1 gene that encodes a fungus-specific kinase known as TOR target in yeast. Genome-wide transcriptome analysis confirmed TOR1 as a regulatory hub that governs T. atroviride metabolism and processes associated to ribosome biogenesis, gene expression and translation. In addition, mycoparasitism-relevant genes encoding terpenoid and polyketide synthases, peptidases, glycoside hydrolases, small secreted cysteine-rich proteins, and G protein coupled receptors emerged as TOR1 targets. Our results provide the first in-depth insights into TOR signaling in a fungal mycoparasite and emphasize its importance in the regulation of processes that critically contribute to the antagonistic activity of T. atroviride.
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Affiliation(s)
- Rossana Segreto
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | - Hoda Bazafkan
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | - Julia Millinger
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | - Martina Schenk
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | - Lea Atanasova
- Institute of Food Technology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Maria Doppler
- Department of Agrobiotechnology IFA-Tulln, Center for Analytical Chemistry, University of Natural, Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Christoph Büschl
- Department of Agrobiotechnology IFA-Tulln, Center for Analytical Chemistry, University of Natural, Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Mélanie Boeckstaens
- Département de Biologie Moléculaire, Laboratory of Biology of Membrane Transport, Université Libre de Bruxelles, Gosselies, Belgium
| | - Silvia Soto Diaz
- Département de Biologie Moléculaire, Laboratory of Biology of Membrane Transport, Université Libre de Bruxelles, Gosselies, Belgium
| | - Ulrike Schreiner
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | | | | | - Rainer Schuhmacher
- Department of Agrobiotechnology IFA-Tulln, Center for Analytical Chemistry, University of Natural, Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Susanne Zeilinger
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
- * E-mail:
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Xie X, Wang Y, Datla R, Ren M. Auxin and Target of Rapamycin Spatiotemporally Regulate Root Organogenesis. Int J Mol Sci 2021; 22:ijms222111357. [PMID: 34768785 PMCID: PMC8583787 DOI: 10.3390/ijms222111357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 10/20/2021] [Indexed: 12/17/2022] Open
Abstract
The programs associated with embryonic roots (ERs), primary roots (PRs), lateral roots (LRs), and adventitious roots (ARs) play crucial roles in the growth and development of roots in plants. The root functions are involved in diverse processes such as water and nutrient absorption and their utilization, the storage of photosynthetic products, and stress tolerance. Hormones and signaling pathways play regulatory roles during root development. Among these, auxin is the most important hormone regulating root development. The target of rapamycin (TOR) signaling pathway has also been shown to play a key role in root developmental programs. In this article, the milestones and influential progress of studying crosstalk between auxin and TOR during the development of ERs, PRs, LRs and ARs, as well as their functional implications in root morphogenesis, development, and architecture, are systematically summarized and discussed.
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Affiliation(s)
- Xiulan Xie
- Labarotary of Space Biology, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; (X.X.); (Y.W.)
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China
- Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
| | - Ying Wang
- Labarotary of Space Biology, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; (X.X.); (Y.W.)
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China
- Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
| | - Raju Datla
- Global Institute for Food Security in Saskatoon, University of Saskatchewan, Saskatoon, SK S7N 0W9, Canada
- Correspondence: (R.D.); (M.R.)
| | - Maozhi Ren
- Labarotary of Space Biology, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; (X.X.); (Y.W.)
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China
- Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
- Correspondence: (R.D.); (M.R.)
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11
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Muñoz-Muñoz PLA, Mares-Alejandre RE, Meléndez-López SG, Ramos-Ibarra MA. Bioinformatic Analysis of Two TOR (Target of Rapamycin)-Like Proteins Encoded by Entamoeba histolytica Revealed Structural Similarities with Functional Homologs. Genes (Basel) 2021; 12:genes12081139. [PMID: 34440318 PMCID: PMC8391992 DOI: 10.3390/genes12081139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/21/2021] [Accepted: 07/24/2021] [Indexed: 01/04/2023] Open
Abstract
The target of rapamycin (TOR), also known as FKBP-rapamycin associated protein (FRAP), is a protein kinase belonging to the PIKK (phosphatidylinositol 3-kinase (PI3K)-related kinases) family. TOR kinases are involved in several signaling pathways that control cell growth and proliferation. Entamoeba histolytica, the protozoan parasite that causes human amoebiasis, contains two genes encoding TOR-like proteins: EhFRAP and EhTOR2. To assess their potential as drug targets to control the cell proliferation of E. histolytica, we studied the structural features of EhFRAP and EhTOR2 using a biocomputational approach. The overall results confirmed that both TOR amoebic homologs share structural similarities with functional TOR kinases, and show inherent abilities to form TORC complexes and participate in protein-protein interaction networks. To our knowledge, this study represents the first in silico characterization of the structure-function relationships of EhFRAP and EhTOR2.
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12
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Alao JP, Legon L, Rallis C. Crosstalk between the mTOR and DNA Damage Response Pathways in Fission Yeast. Cells 2021; 10:cells10020305. [PMID: 33540829 PMCID: PMC7913062 DOI: 10.3390/cells10020305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/14/2022] Open
Abstract
Cells have developed response systems to constantly monitor environmental changes and accordingly adjust growth, differentiation, and cellular stress programs. The evolutionarily conserved, nutrient-responsive, mechanistic target of rapamycin signaling (mTOR) pathway coordinates basic anabolic and catabolic cellular processes such as gene transcription, protein translation, autophagy, and metabolism, and is directly implicated in cellular and organismal aging as well as age-related diseases. mTOR mediates these processes in response to a broad range of inputs such as oxygen, amino acids, hormones, and energy levels, as well as stresses, including DNA damage. Here, we briefly summarize data relating to the interplays of the mTOR pathway with DNA damage response pathways in fission yeast, a favorite model in cell biology, and how these interactions shape cell decisions, growth, and cell-cycle progression. We, especially, comment on the roles of caffeine-mediated DNA-damage override. Understanding the biology of nutrient response, DNA damage and related pharmacological treatments can lead to the design of interventions towards improved cellular and organismal fitness, health, and survival.
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Affiliation(s)
- John-Patrick Alao
- ZEAB Therapeutic, University of East London, Stratford Campus, Water Lane, Stratford, London E15 4LZ, UK;
| | - Luc Legon
- School of Health, Sport and Bioscience, University of East London, Stratford Campus, Water Lane, Stratford, London E15 4LZ, UK;
| | - Charalampos Rallis
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
- Correspondence:
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13
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Pataki E, Simhaev L, Engel H, Cohen A, Kupiec M, Weisman R. TOR Complex 2- independent mutations in the regulatory PIF pocket of Gad8AKT1/SGK1 define separate branches of the stress response mechanisms in fission yeast. PLoS Genet 2020; 16:e1009196. [PMID: 33137119 PMCID: PMC7660925 DOI: 10.1371/journal.pgen.1009196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/12/2020] [Accepted: 10/14/2020] [Indexed: 12/12/2022] Open
Abstract
The Target of rapamycin (TOR) protein kinase forms part of TOR complex 1 (TORC1) and TOR complex 2 (TORC2), two multi-subunit protein complexes that regulate growth, proliferation, survival and developmental processes by phosphorylation and activation of AGC-family kinases. In the fission yeast, Schizosaccharomyces pombe, TORC2 and its target, the AGC kinase Gad8 (an orthologue of human AKT or SGK1) are required for viability under stress conditions and for developmental processes in response to starvation cues. In this study, we describe the isolation of gad8 mutant alleles that bypass the requirement for TORC2 and reveal a separation of function of TORC2 and Gad8 under stress conditions. In particular, osmotic and nutritional stress responses appear to form a separate branch from genotoxic stress responses downstream of TORC2-Gad8. Interestingly, TORC2-independent mutations map into the regulatory PIF pocket of Gad8, a highly conserved motif in AGC kinases that regulates substrate binding in PDK1 (phosphoinositide dependent kinase-1) and kinase activity in several AGC kinases. Gad8 activation is thought to require a two-step mechanism, in which phosphorylation by TORC2 allows further phosphorylation and activation by Ksg1 (an orthologue of PDK1). We focus on the Gad8-K263C mutation and demonstrate that it renders the Gad8 kinase activity independent of TORC2 in vitro and independent of the phosphorylation sites of TORC2 in vivo. Molecular dynamics simulations of Gad8-K263C revealed abnormal high flexibility at T387, the phosphorylation site for Ksg1, suggesting a mechanism for the TORC2-independent Gad8 activity. Significantly, the K263 residue is highly conserved in the family of AGC-kinases, which may suggest a general way of keeping their activity in check when acting downstream of TOR complexes. Protein kinases catalyze the transfer of phosphate from high-energy, phosphate-donating molecules, such as ATP, to their substrates. This process is pivotal for regulation of almost any aspect of cellular biology. Many human diseases are associated with aberrant functions of protein kinases due to mutations. Accordingly, there is a growing number of kinase inhibitors that have been approved for clinical use. A better understanding of how protein kinases become active and how their activity is relayed to regulate their cellular functions is much needed for rational design of kinase inhibitors and for their optimal use in the clinic. The AGC-family of protein kinases play key roles in regulating cellular growth, proliferation and survival. In human cells, as well as in the fission yeast, our cellular model system, a subgroup of the AGC kinases is activated by the TOR protein kinases. Here we report the isolation of mutations in the AGC kinase Gad8 (AKT or SGK1 in human) that bypass the requirement for activation by TOR. Analyses of how these mutations affect cellular growth revealed separate branches of stress response mechanisms downstream of Gad8, while computer simulation methods suggested a molecular mechanism that keeps the activity of Gad8 in check.
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Affiliation(s)
- Emese Pataki
- Department of Natural and Life Sciences, The Open University of Israel, Ra'anana, Israel
| | - Luba Simhaev
- Blavatnik Center for Drug Discovery, Tel Aviv University, Tel Aviv, Israel
| | - Hamutal Engel
- Blavatnik Center for Drug Discovery, Tel Aviv University, Tel Aviv, Israel
| | - Adiel Cohen
- Department of Natural and Life Sciences, The Open University of Israel, Ra'anana, Israel
| | - Martin Kupiec
- The Shmunis School of Biomedicine & Cancer Research, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Ronit Weisman
- Department of Natural and Life Sciences, The Open University of Israel, Ra'anana, Israel
- * E-mail:
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14
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Ingargiola C, Turqueto Duarte G, Robaglia C, Leprince AS, Meyer C. The Plant Target of Rapamycin: A Conduc TOR of Nutrition and Metabolism in Photosynthetic Organisms. Genes (Basel) 2020; 11:genes11111285. [PMID: 33138108 PMCID: PMC7694126 DOI: 10.3390/genes11111285] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 12/15/2022] Open
Abstract
Living organisms possess many mechanisms to sense nutrients and favorable conditions, which allow them to grow and develop. Photosynthetic organisms are very diverse, from green unicellular algae to multicellular flowering plants, but most of them are sessile and thus unable to escape from the biotic and abiotic stresses they experience. The Target of Rapamycin (TOR) signaling pathway is conserved in all eukaryotes and acts as a central regulatory hub between growth and extrinsic factors, such as nutrients or stress. However, relatively little is known about the regulations and roles of this pathway in plants and algae. Although some features of the TOR pathway seem to have been highly conserved throughout evolution, others clearly differ in plants, perhaps reflecting adaptations to different lifestyles and the rewiring of this primordial signaling module to adapt to specific requirements. Indeed, TOR is involved in plant responses to a vast array of signals including nutrients, hormones, light, stresses or pathogens. In this review, we will summarize recent studies that address the regulations of TOR by nutrients in photosynthetic organisms, and the roles of TOR in controlling important metabolic pathways, highlighting similarities and differences with the other eukaryotes.
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Affiliation(s)
- Camille Ingargiola
- Institut Jean-Pierre Bourgin (IJPB), INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France; (C.I.); (G.T.D.); (A.-S.L.)
| | - Gustavo Turqueto Duarte
- Institut Jean-Pierre Bourgin (IJPB), INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France; (C.I.); (G.T.D.); (A.-S.L.)
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Christophe Robaglia
- Laboratoire de Génétique et Biophysique des Plantes, Faculté des Sciences de Luminy, UMR 7265, CEA, CNRS, BIAM, Aix Marseille Université, 13009 Marseille, France;
| | - Anne-Sophie Leprince
- Institut Jean-Pierre Bourgin (IJPB), INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France; (C.I.); (G.T.D.); (A.-S.L.)
- Faculté des Sciences et d’Ingénierie, Sorbonne Université, UFR 927, 4 Place Jussieu, 75252 Paris, France
| | - Christian Meyer
- Institut Jean-Pierre Bourgin (IJPB), INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France; (C.I.); (G.T.D.); (A.-S.L.)
- Correspondence:
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15
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Laribee RN, Weisman R. Nuclear Functions of TOR: Impact on Transcription and the Epigenome. Genes (Basel) 2020; 11:E641. [PMID: 32532005 PMCID: PMC7349558 DOI: 10.3390/genes11060641] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 12/15/2022] Open
Abstract
The target of rapamycin (TOR) protein kinase is at the core of growth factor- and nutrient-dependent signaling pathways that are well-known for their regulation of metabolism, growth, and proliferation. However, TOR is also involved in the regulation of gene expression, genomic and epigenomic stability. TOR affects nuclear functions indirectly through its activity in the cytoplasm, but also directly through active nuclear TOR pools. The mechanisms by which TOR regulates its nuclear functions are less well-understood compared with its cytoplasmic activities. TOR is an important pharmacological target for several diseases, including cancer, metabolic and neurological disorders. Thus, studies of the nuclear functions of TOR are important for our understanding of basic biological processes, as well as for clinical implications.
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Affiliation(s)
- R. Nicholas Laribee
- Department of Pathology and Laboratory Medicine, College of Medicine and Center for Cancer Research, University of Tennessee Health Science Center, 19 South Manassas, Cancer Research Building Rm 318, Memphis, TN 38163, USA
| | - Ronit Weisman
- Department of Natural and Life Sciences, The Open University of Israel, University Road 1, Ra’anana 4353701, Israel
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16
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Shao J, Wang L, Shao X, Liu M. Dietary Different Replacement Levels of Fishmeal by Fish Silage Could Influence Growth of Litopenaeus vannamei by Regulating mTOR at Transcriptional Level. Front Physiol 2020; 11:359. [PMID: 32477153 PMCID: PMC7232572 DOI: 10.3389/fphys.2020.00359] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 03/27/2020] [Indexed: 11/13/2022] Open
Abstract
Fish silage (FS) has been confirmed as a high-quality feed ingredient because of its balanced nutrition, low cost, and environmental friendliness. In the present study, we evaluated the performance of replacing fishmeal by FS in the diet of white shrimp, Litopenaeus vannamei. Five isonitrogenous (410 g kg-1) and isolipidic (75 g kg-1) diets were formulated with replacement of fishmeal by 0% (FM), 25% (FS25%), 50% (FS50%), 75% (FS75%), and 100% (FS100%) FS. After an 8-week trial, shrimps fed low FS diets (FM and FS25%) had significantly higher final weight (FW), weight gain (WG), and specific growth ratio (SGR) (P < 0.05). No significant differences were found in body composition and most antioxidant enzyme activities of all groups (P > 0.05). Compared to high FS groups (FS75% and FS100%), low FS replacement levels (0 and 25%) had enhanced trypsin activity. And trypsin transcriptional level presented a similar trend with trypsin activity. In terms of intestinal histopathology, no obvious histological damage was observed in the intestine of all groups. tor and s6k of low replacement level groups (FM and FS25%) were significantly upregulated (P < 0.05), which indicated activation of mammalian target of rapamycin (mTOR) signaling pathway in low FS groups at transcriptional level. The enhanced performances of growth and mTOR signaling pathway in low FS groups (FM and FS25%) provided us some insights into the regulation mechanism of nutrient signal on growth. Based on the above, dietary FS could influence the growth of shrimp by regulating mTOR at the transcriptional level, and FS is a potential substitute of fishmeal in shrimp feed.
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Affiliation(s)
- Jianchun Shao
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Lei Wang
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Xuqing Shao
- Shandong Cigna Detection Technology Co., Ltd., Qingdao, China
| | - Mei Liu
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
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17
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Kang Y, Li Y, Wen H, Zhu J, Zheng J, Feng Z. Prevention of renal ischemia and reperfusion injury by penehyclidine hydrochloride through autophagy activation. Mol Med Rep 2020; 21:2182-2192. [PMID: 32186764 PMCID: PMC7115187 DOI: 10.3892/mmr.2020.11024] [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: 06/11/2019] [Accepted: 11/29/2019] [Indexed: 11/06/2022] Open
Abstract
Penehyclidine hydrochloride (PHC) suppresses renal ischemia and reperfusion (I/R) injury (IRI); however, the underlying mechanism of action that achieves this function remains largely unknown. The present study aimed to investigate the potential role of autophagy in PHC‑induced suppression of renal IRI, as well as the involvement of cell proliferation and apoptosis. A rat IRI model and a cellular hypoxia/oxygenation (H/R) model were established; PHC, 3‑methyladenine (3‑MA) and rapamycin (Rapa) were administered to the IRI model rats prior to I/R induction and to H/R cells following reperfusion. Serum creatinine was measured using a biochemistry analyzer, whereas aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) expression levels were detected using ELISA kits. Renal tissue injury was evaluated by histological examination. In addition, microtubule‑associated protein light chain 3B (LC3B) expression, autophagosome formation, cell proliferation and apoptosis were detected in the cellular H/R model. The results demonstrated that I/R induced renal injury in IRI model rats, upregulated serum creatinine, ALAT and ASAT expression levels, and increased autophagic processes. In contrast, pretreatment with PHC or Rapa significantly prevented these I/R‑induced changes, whereas the administration of 3‑MA enhanced I/R‑induced injuries through suppressing autophagy. PHC and Rapa increased LC3B and Beclin‑1 expression levels, but decreased sequestome 1 (p62) expression in the cellular H/R model, whereas 3‑MA prevented these PHC‑induced changes. PHC and Rapa promoted proliferation and autophagy in the cellular H/R model; these effects were accompanied by increased expression levels of LC3B and Beclin‑1, and reduced p62 expression levels, whereas these levels were inhibited by 3‑MA. Furthermore, PHC and Rapa inhibited apoptosis in the cellular H/R model through increasing Bcl‑2 expression levels, and suppressing Bax and caspase‑3 expression levels; the opposite effect was induced by 3‑MA. In conclusion, PHC suppressed renal IRI through the induction of autophagy, which in turn promoted proliferation and suppressed apoptosis in renal cells.
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Affiliation(s)
- Yuqing Kang
- Department of Anesthesiology, Jinshan Branch Hospital of Shanghai Sixth People's Hospital, Shanghai 201599, P.R. China
| | - Yuebing Li
- Department of Anesthesiology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310005, P.R. China
| | - Heng Wen
- Department of Anesthesiology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310005, P.R. China
| | - Junfeng Zhu
- Department of Anesthesiology, Jinshan Branch Hospital of Shanghai Sixth People's Hospital, Shanghai 201599, P.R. China
| | - Jiangbo Zheng
- Department of Anesthesiology, Jinshan Branch Hospital of Shanghai Sixth People's Hospital, Shanghai 201599, P.R. China
| | - Zhaoming Feng
- Department of Anesthesiology, Jinshan Branch Hospital of Shanghai Sixth People's Hospital, Shanghai 201599, P.R. China
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18
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Candiracci J, Migeot V, Chionh YH, Bauer F, Brochier T, Russell B, Shiozaki K, Dedon P, Hermand D. Reciprocal regulation of TORC signaling and tRNA modifications by Elongator enforces nutrient-dependent cell fate. SCIENCE ADVANCES 2019; 5:eaav0184. [PMID: 31223645 PMCID: PMC6584457 DOI: 10.1126/sciadv.aav0184] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 05/14/2019] [Indexed: 06/09/2023]
Abstract
Nutrient availability has a profound impact on cell fate. Upon nitrogen starvation, wild-type fission yeast cells uncouple cell growth from cell division to generate small, round-shaped cells that are competent for sexual differentiation. The TORC1 (TOR complex 1) and TORC2 complexes exert opposite controls on cell growth and cell differentiation, but little is known about how their activity is coordinated. We show that transfer RNA (tRNA) modifications by Elongator are critical for this regulation by promoting the translation of both key components of TORC2 and repressors of TORC1. We further identified the TORC2 pathway as an activator of Elongator by down-regulating a Gsk3 (glycogen synthase kinase 3)-dependent inhibitory phosphorylation of Elongator. Therefore, a feedback control is operating between TOR complex (TORC) signaling and tRNA modification by Elongator to enforce the advancement of mitosis that precedes cell differentiation.
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Affiliation(s)
- Julie Candiracci
- URPHYM-GEMO, University of Namur, rue de Bruxelles, 61, Namur 5000, Belgium
| | - Valerie Migeot
- URPHYM-GEMO, University of Namur, rue de Bruxelles, 61, Namur 5000, Belgium
| | - Yok-Hian Chionh
- Singapore–MIT Alliance for Research and Technology Centre (SMART), Center for Life Sciences 05-06, 28 Medical Drive, 117456 Singapore
| | - Fanelie Bauer
- URPHYM-GEMO, University of Namur, rue de Bruxelles, 61, Namur 5000, Belgium
| | - Thomas Brochier
- URPHYM-GEMO, University of Namur, rue de Bruxelles, 61, Namur 5000, Belgium
| | - Brandon Russell
- Massachusetts Institute of Technology, 56-787B77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA
| | - Kazuhiro Shiozaki
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
| | - Peter Dedon
- Singapore–MIT Alliance for Research and Technology Centre (SMART), Center for Life Sciences 05-06, 28 Medical Drive, 117456 Singapore
- Massachusetts Institute of Technology, 56-787B77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA
| | - Damien Hermand
- URPHYM-GEMO, University of Namur, rue de Bruxelles, 61, Namur 5000, Belgium
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19
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Forte GM, Davie E, Lie S, Franz-Wachtel M, Ovens AJ, Wang T, Oakhill JS, Maček B, Hagan IM, Petersen J. Import of extracellular ATP in yeast and man modulates AMPK and TORC1 signalling. J Cell Sci 2019; 132:jcs223925. [PMID: 30814334 PMCID: PMC6467490 DOI: 10.1242/jcs.223925] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 02/15/2019] [Indexed: 01/31/2023] Open
Abstract
AMP-activated kinase (AMPK) and target of rapamycin (TOR) signalling coordinate cell growth, proliferation, metabolism and cell survival with the nutrient environment of cells. The poor vasculature and nutritional stress experienced by cells in solid tumours raises the question: how do they assimilate sufficient nutrients to survive? Here, we show that human and fission yeast cells import ATP and AMP from their external environment to regulate AMPK and TOR signalling. Exposure of fission yeast (Schizosaccharomyces pombe) and human cells to external AMP impeded cell growth; however, in yeast this restraining impact required AMPK. In contrast, external ATP rescued the growth defect of yeast mutants with reduced TORC1 signalling; furthermore, exogenous ATP transiently enhanced TORC1 signalling in both yeast and human cell lines. Addition of the PANX1 channel inhibitor probenecid blocked ATP import into human cell lines suggesting that this channel may be responsible for both ATP release and uptake in mammals. In light of these findings, it is possible that the higher extracellular ATP concentration reported in solid tumours is both scavenged and recognized as an additional energy source beneficial for cell growth.
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Affiliation(s)
- Gabriella M Forte
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Elizabeth Davie
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Shervi Lie
- Flinders Centre for Innovation in Cancer, College of Medicine & Public health, Flinders University, Adelaide, SA 5001, Australia
| | - Mirita Franz-Wachtel
- Proteome Center Tuebingen, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Ashley J Ovens
- Metabolic Signalling Laboratory, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Victoria 3065, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Victoria 3000, Australia
| | - Tingting Wang
- Flinders Centre for Innovation in Cancer, College of Medicine & Public health, Flinders University, Adelaide, SA 5001, Australia
| | - Jonathan S Oakhill
- Metabolic Signalling Laboratory, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Victoria 3065, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Victoria 3000, Australia
| | - Boris Maček
- Proteome Center Tuebingen, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Iain M Hagan
- Cancer Research UK Manchester institute, Alderley Park, Macclesfield SK10 4TG, United Kingdom
| | - Janni Petersen
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, United Kingdom
- Flinders Centre for Innovation in Cancer, College of Medicine & Public health, Flinders University, Adelaide, SA 5001, Australia
- South Australia Health and Medical Research Institute, North Terrace, PO Box 11060, Adelaide SA 5000 Australia
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20
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Lie S, Banks P, Lawless C, Lydall D, Petersen J. The contribution of non-essential Schizosaccharomyces pombe genes to fitness in response to altered nutrient supply and target of rapamycin activity. Open Biol 2019; 8:rsob.180015. [PMID: 29720420 PMCID: PMC5990653 DOI: 10.1098/rsob.180015] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 04/06/2018] [Indexed: 12/12/2022] Open
Abstract
Nutrient fluctuations in the cellular environment promote changes in cell metabolism and growth to adapt cell proliferation accordingly. The target of rapamycin (TOR) signalling network plays a key role in the coordination of growth and cell proliferation with the nutrient environment and, importantly, nutrient limitation reduces TOR complex 1 (TORC1) signalling. We have performed global quantitative fitness profiling of the collection of Schizosaccharomyces pombe strains from which non-essential genes have been deleted. We identified genes that regulate fitness when cells are grown in a nutrient-rich environment compared with minimal environments, with varying nitrogen sources including ammonium, glutamate and proline. In addition, we have performed the first global screen for genes that regulate fitness when both TORC1 and TORC2 signalling is reduced by Torin1. Analysis of genes whose deletions altered fitness when nutrients were limited, or when TOR signalling was compromised, identified a large number of genes that regulate transmembrane transport, transcription and chromatin organization/regulation and vesicle-mediated transport. The ability to tolerate reduced TOR signalling placed demands upon a large number of biological processes including autophagy, mRNA metabolic processing and nucleocytoplasmic transport. Importantly, novel biological processes and all processes known to be regulated by TOR were identified in our screens. In addition, deletion of 62 genes conserved in humans gave rise to strong sensitivity or resistance to Torin1, and 29 of these 62 genes have novel links to TOR signalling. The identification of chromatin and transcriptional regulation, nutritional uptake and transport pathways in this powerful genetic model now paves the way for a molecular understanding of how cells adapt to the chronic and acute fluctuations in nutrient supply that all eukaryotes experience at some stage, and which is a key feature of cancer cells within solid tumours.
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Affiliation(s)
- Shervi Lie
- Flinders Centre for Innovation in Cancer, College of Medicine & Public Health, Flinders University, Bedford Park, Adelaide, South Australia 5042, Australia
| | - Peter Banks
- High Throughput Screening Facility, Newcastle Biomedicine, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Conor Lawless
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - David Lydall
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - Janni Petersen
- Flinders Centre for Innovation in Cancer, College of Medicine & Public Health, Flinders University, Bedford Park, Adelaide, South Australia 5042, Australia .,South Australia Health and Medical Research Institute, North Terrace, PO Box 11060, Adelaide, South Australia 5000, Australia
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21
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Lie S, Wang T, Forbes B, Proud CG, Petersen J. The ability to utilise ammonia as nitrogen source is cell type specific and intricately linked to GDH, AMPK and mTORC1. Sci Rep 2019; 9:1461. [PMID: 30728400 PMCID: PMC6365639 DOI: 10.1038/s41598-018-37509-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 11/28/2018] [Indexed: 11/23/2022] Open
Abstract
Ammonia can be utilised as an alternative nitrogen source to glutamine to support cell proliferation. However, the underlying molecular mechanisms and whether all cells have this ability is not fully understood. We find that eleven cancer and non-cancerous cell lines have opposite abilities to tolerate and utilise ammonia to support proliferation in a glutamine-depleted environment. HEK293, Huh7, T47D and MCF7 cells can use ammonia, when starved of glutamine, to support proliferation to varying degrees. Glutamine depletion reduced mTORC1 activity, while additional ammonia supplementation diminished this mTORC1 inhibition. Depletion of glutamine promoted a rapid and transient activation of AMPK, whereas, additional ammonia supplementation blocked this starvation-induced AMPK activation. As expected, drug-induced AMPK activation reduced cell proliferation in glutamine-depleted cells supplemented with ammonia. Surprisingly, mTORC1 activity was largely unchanged despite the enhanced AMPK activity, suggesting that AMPK does not inhibit mTORC1 signalling under these conditions. Finally, glutamate dehydrogenase (GDH) inhibition, a key enzyme regulating ammonia assimilation, leads to AMPK activation, mTORC1 inhibition and reduced proliferation. Ammonia provides an alternative nitrogen source that aids certain cancer cells ability to thrive in nutrient-deprived environment. The ability of cells to utilise ammonia as a nitrogen source is intricately linked to AMPK, mTORC1 and GDH.
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Affiliation(s)
- Shervi Lie
- Flinders Centre for Innovation in Cancer, College of Medicine and Public health, Flinders University, Adelaide, SA, 5042, Australia
| | - Tingting Wang
- Flinders Centre for Innovation in Cancer, College of Medicine and Public health, Flinders University, Adelaide, SA, 5042, Australia
| | - Briony Forbes
- Flinders Centre for Innovation in Cancer, College of Medicine and Public health, Flinders University, Adelaide, SA, 5042, Australia
| | - Christopher G Proud
- Nutrition and Metabolism, South Australia Health and Medical Research Institute, North Terrace, PO Box 11060, Adelaide, SA, 5000, Australia
| | - Janni Petersen
- Flinders Centre for Innovation in Cancer, College of Medicine and Public health, Flinders University, Adelaide, SA, 5042, Australia. .,Nutrition and Metabolism, South Australia Health and Medical Research Institute, North Terrace, PO Box 11060, Adelaide, SA, 5000, Australia.
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22
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Esnault C, Lee M, Ham C, Levin HL. Transposable element insertions in fission yeast drive adaptation to environmental stress. Genome Res 2018; 29:85-95. [PMID: 30541785 PMCID: PMC6314160 DOI: 10.1101/gr.239699.118] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 11/15/2018] [Indexed: 01/06/2023]
Abstract
Cells are regularly exposed to a range of naturally occurring stress that can restrict growth or cause lethality. In response, cells activate expression networks with hundreds of genes that together increase resistance to common environmental insults. However, stress response networks can be insufficient to ensure survival, which raises the question of whether cells possess genetic programs that can promote adaptation to novel forms of stress. We found transposable element (TE) mobility in Schizosaccharomyces pombe was greatly increased when cells were exposed to unusual forms of stress such as heavy metals, caffeine, and the plasticizer phthalate. By subjecting TE-tagged cells to CoCl2, we found the TE integration provided the major path to resistance. Groups of insertions that provided resistance were linked to TOR regulation and metal response genes. We extended our study of adaptation by analyzing TE positions in 57 genetically distinct wild strains. The genomic positions of 1048 polymorphic LTRs were strongly associated with a range of stress response genes, indicating TE integration promotes adaptation in natural conditions. These data provide strong support for the idea, first proposed by Barbara McClintock, that TEs provide a system to modify the genome in response to stress.
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Affiliation(s)
- Caroline Esnault
- Section on Eukaryotic Transposable Elements, Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Michael Lee
- Section on Eukaryotic Transposable Elements, Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Chloe Ham
- Section on Eukaryotic Transposable Elements, Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Henry L Levin
- Section on Eukaryotic Transposable Elements, Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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23
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Gao J, Guo HJ, Sun YC, Ge F. Juvenile hormone mediates the positive effects of nitrogen fertilization on weight and reproduction in pea aphid. PEST MANAGEMENT SCIENCE 2018; 74:2511-2519. [PMID: 29656587 DOI: 10.1002/ps.4932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/25/2018] [Accepted: 04/04/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND The positive effects of nitrogen fertilization on the performance of phytophagous insects have been reported extensively; the physiological and molecular basis involved, however, is largely unclear. Here, we test experimentally whether enhancement of juvenile hormone (JH) is responsible for the increased weight and fecundity of pea aphid (Acyrthosiphon pisum) under nitrogen fertilization. RESULTS Aphids fed on Medicago truncatula with nitrogen fertilization have a greater amino acid content, higher weight at the fourth instar and adult stage, and produce more offspring than those without nitrogen fertilization. Furthermore, nitrogen fertilization upregulates the transcripts of JH biosynthesis-related genes and increases JH titre at the fourth instar and adult stage, suggesting that JH is involved in the positive responses of aphids to nitrogen fertilization. Application of 100 ng JH increases adult weight and fecundity in aphids fed on M. truncatula without nitrogen fertilization. Conversely, impairing JH signalling by pharmacologically inhibiting the target of rapamycin pathway or by knocking down JH biosynthetic gene decreases adult weight and fecundity in aphids fed on M. truncatula with nitrogen fertilization, whereas application of JH rescued the phenotype. CONCLUSION The increased JH titre at the fourth instar and adult stage is required for the increases of weight and fecundity of A. pisum under nitrogen fertilization. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Jing Gao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hui Juan Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yu Cheng Sun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Feng Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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24
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Ribeiro GF, de Góes CG, Onorio DS, de Campos CBL, Morais FV. Autophagy in Paracoccidioides brasiliensis under normal mycelia to yeast transition and under selective nutrient deprivation. PLoS One 2018; 13:e0202529. [PMID: 30138387 PMCID: PMC6107164 DOI: 10.1371/journal.pone.0202529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 08/03/2018] [Indexed: 11/23/2022] Open
Abstract
Paracoccidioides spp. is a thermally dimorphic fungus endemic to Latin America and the etiological agent of paracoccidioidomycosis (PCM), a granulomatous disease acquired through fungal propagule inhalation by its mammalian host. The infection is established after successful mycelia to yeast transition in the host pulmonary alveoli. The challenging environment inside the host exposes the fungus to the need of adaptation in order to circumvent nutritional, thermal, oxidative, immunological and other stresses that can directly affect their survival. Considering that autophagy is a response to abrupt environmental changes and is induced by stress conditions, this study hypothesizes that this process might be crucially involved in the adaptation of Paracoccidioides spp. to the host and, therefore, it is essential for the proper establishment of the disease. By labelling autophagous vesicles with monodansylcadaverine, autophagy was observed as an early event in cells during the normal mycelium to yeast transition, as well as in yeast cells of P. brasiliensis under glucose deprivation, and under either rapamycin or 3-methyladenine (3-MA). Findings in this study demonstrated that autophagy is triggered in P. brasiliensis during the thermal-induced mycelium to yeast transition and by glucose-limited conditions in yeasts, both of which modulated by rapamycin or 3-MA. Certainly, further genetic and in vivo analyses are needed in order to finally address the contribution of autophagy for adaptation. Yet, our data propose that autophagy possibly plays an important role in Paracoccidioides brasiliensis virulence and pathogenicity.
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Affiliation(s)
- Giselle Ferreira Ribeiro
- Laboratório de Biologia Celular e Molecular de Fungos, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, SP, Brazil
| | - Caroline Gonçalves de Góes
- Laboratório de Biologia Celular e Molecular de Fungos, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, SP, Brazil
| | - Diego Santos Onorio
- Laboratório de Biologia Celular e Molecular de Fungos, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, SP, Brazil
| | - Cláudia Barbosa Ladeira de Campos
- Laboratório de Bioquímica, Biologia Celular e Molecular de Fungos, Instituto de Ciência e Tecnologia–Universidade Federal de São Paulo–UNIFESP, São José dos Campos, SP, Brazil
| | - Flavia Villaça Morais
- Laboratório de Biologia Celular e Molecular de Fungos, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, SP, Brazil
- * E-mail:
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25
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Shao J, Zhao W, Liu X, Wang L. Growth Performance, Digestive Enzymes, and TOR Signaling Pathway of Litopenaeus vannamei Are Not Significantly Affected by Dietary Protein Hydrolysates in Practical Conditions. Front Physiol 2018; 9:998. [PMID: 30154724 PMCID: PMC6102590 DOI: 10.3389/fphys.2018.00998] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/09/2018] [Indexed: 12/01/2022] Open
Abstract
Protein hydrolysates have been widely reported as the protein source of aquatic feed. However, previous studies on protein hydrolysates focused on fish under experimental conditions. In this study, a 6-week feeding trial in a greenhouse was conducted to investigate the effects of partially replacing fishmeal by protein hydrolysates on growth performance, digestive enzymes, and TOR signaling pathway of Litopenaeus vannamei under practical conditions. This involved randomly selecting 72,000 shrimps (initial body weight 2.26 ± 0.02 g) and placing them in groups inside nine concrete tanks (L 5 m × W 5 m × H 1 m) (3 treatments × 3 replicates × 8000 individuals per concrete tank). Two isonitrogenous (430 g kg-1) and isolipidic (80 g kg-1) diets were prepared: fishmeal diet (FM) containing 400g kg-1 fishmeal, and protein hydrolysates diet (PH) in which 15% of the fishmeal was replaced by protein hydrolysates. A commercial diet (CD) was used as reference. The final weight (FW), percent weight gain (PWG), specific growth ratio (SGR), and total weight for each tank (TW) of L. vannamei fed with FM and PH diets were not significantly different (P > 0.05). However, shrimp fed with PH diet had significantly higher FW, PWG, SGR, and TW values than those fed with CD diet (P < 0.05). Trypsin activity was significantly lower in shrimp fed with CD diet, than in shrimp fed with FM and PH diets (P < 0.05). However, trypsin activity of L. vannamei fed with FM and PH diets were not significantly different (P > 0.05). The mRNA expression of tor, s6k, and 4e-bp genes were not significantly affected between FM and PH diets, while tor and s6k expression levels of CD diet were significantly down-regulated. Based on the above data, 15% replacement of fishmeal with protein hydrolysates did not make any difference on shrimps compared with FM group. Therefore, protein hydrolysates can partially replace fishmeal as the protein source of shrimp formula feed in practical conditions.
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Affiliation(s)
- Jianchun Shao
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wei Zhao
- Department of Life Science and Biotechnology, Research Center of Hydrobiology, Jinan University, Guangzhou, China
| | - Xinwei Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lei Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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26
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Inaba JI, Nagy PD. Tombusvirus RNA replication depends on the TOR pathway in yeast and plants. Virology 2018; 519:207-222. [PMID: 29734044 DOI: 10.1016/j.virol.2018.04.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/09/2018] [Accepted: 04/15/2018] [Indexed: 02/06/2023]
Abstract
Similar to other (+)RNA viruses, tomato bushy stunt virus (TBSV) utilizes metabolites, lipids, membranes, and co-opted host factors during replication. The coordination of cell metabolism and growth with environmental cues is performed by the target of rapamycin (TOR) kinase in eukaryotic cells. In this paper, we find that TBSV replication partially inhibits TOR activity, likely due to recruitment of glycolytic enzymes to the viral replication compartment, which results in reduced ATP levels in the cytosol. Complete inhibition of TOR activity with rapamycin in yeast or AZD8055 inhibitor in plants reduces tombusvirus replication. We find that high glucose concentration, which stimulates TOR activity, enhanced tombusvirus replication in yeast. Depletion of yeast Sch9 or plant S6K1 kinase, a downstream effector of TOR, also inhibited tombusvirus replication in yeast and plant or the assembly of the viral replicase in vitro. Altogether, the TOR pathway is crucial for TBSV to replicate efficiently in hosts.
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Affiliation(s)
- Jun-Ichi Inaba
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546, United States
| | - Peter D Nagy
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546, United States.
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27
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Cohen A, Habib A, Laor D, Yadav S, Kupiec M, Weisman R. TOR complex 2 in fission yeast is required for chromatin-mediated gene silencing and assembly of heterochromatic domains at subtelomeres. J Biol Chem 2018; 293:8138-8150. [PMID: 29632066 DOI: 10.1074/jbc.ra118.002270] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/14/2018] [Indexed: 12/21/2022] Open
Abstract
The conserved serine/threonine protein kinase target of rapamycin (TOR) is a major regulator of eukaryotic cellular and organismal growth and a valuable target for drug therapy. TOR forms the core of two evolutionary conserved complexes, TOR complex 1 (TORC1) and TORC2. In the fission yeast Schizosaccharomyces pombe, TORC2 responds to glucose levels and, by activating the protein kinase Gad8 (an orthologue of human AKT), is required for well-regulated cell cycle progression, starvation responses, and cell survival. Here, we report that TORC2-Gad8 is also required for gene silencing and the formation of heterochromatin at the S. pombe mating-type locus and at subtelomeric regions. Deletion of TORC2-Gad8 resulted in loss of the heterochromatic modification of histone 3 lysine 9 dimethylation (H3K9me2) and an increase in euchromatic modifications, including histone 3 lysine 4 trimethylation (H3K4me3) and histone 4 lysine 16 acetylation (H4K16Ac). Accumulation of RNA polymerase II (Pol II) at subtelomeric genes in TORC2-Gad8 mutant cells indicated a defect in silencing at the transcriptional level. Moreover, a concurrent decrease in histone 4 lysine 20 dimethylation (H4K20me2) suggested elevated histone turnover. Loss of gene silencing in cells lacking TORC2-Gad8 is partially suppressed by loss of the anti-silencer Epe1 and fully suppressed by loss of the Pol II-associated Paf1 complex, two chromatin regulators that have been implicated in heterochromatin stability and spreading. Taken together, our findings suggest that TORC2-Gad8 signaling contributes to epigenetic stability at subtelomeric regions and the mating-type locus in S. pombe.
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Affiliation(s)
- Adiel Cohen
- Department of Natural and Life Sciences, Open University of Israel, University Road 1, 4353701 Ranana, Israel
| | - Aline Habib
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69977801, Tel Aviv, Israel
| | - Dana Laor
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69977801, Tel Aviv, Israel
| | - Sudhanshu Yadav
- Department of Natural and Life Sciences, Open University of Israel, University Road 1, 4353701 Ranana, Israel
| | - Martin Kupiec
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69977801, Tel Aviv, Israel
| | - Ronit Weisman
- Department of Natural and Life Sciences, Open University of Israel, University Road 1, 4353701 Ranana, Israel.
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28
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Pérez-Hidalgo L, Moreno S. Coupling TOR to the Cell Cycle by the Greatwall-Endosulfine-PP2A-B55 Pathway. Biomolecules 2017; 7:biom7030059. [PMID: 28777780 PMCID: PMC5618240 DOI: 10.3390/biom7030059] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 07/31/2017] [Accepted: 08/02/2017] [Indexed: 01/14/2023] Open
Abstract
Cell growth and division are two processes tightly coupled in proliferating cells. While Target of Rapamycin (TOR) is the master regulator of growth, the cell cycle is dictated by the activity of the cyclin-dependent kinases (CDKs). A long-standing question in cell biology is how these processes may be connected. Recent work has highlighted that regulating the phosphatases that revert CDK phosphorylations is as important as regulating the CDKs for cell cycle progression. At mitosis, maintaining a low level of protein phosphatase 2A (PP2A)-B55 activity is essential for CDK substrates to achieve the correct level of phosphorylation. The conserved Greatwall–Endosulfine pathway has been shown to be required for PP2A-B55 inhibition at mitosis in yeasts and multicellular organisms. Interestingly, in yeasts, the Greatwall–Endosulfine pathway is negatively regulated by TOR Complex 1 (TORC1). Moreover, Greatwall–Endosulfine activation upon TORC1 inhibition has been shown to regulate the progression of the cell cycle at different points: the G1 phase in budding yeast, the G2/M transition and the differentiation response in fission yeast, and the entry into quiescence in both budding and fission yeasts. In this review, we discuss the recent findings on how the Greatwall–Endosulfine pathway may provide a connection between cell growth and the cell cycle machinery.
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Affiliation(s)
- Livia Pérez-Hidalgo
- Institute of Functional Biology and Genomics (IBFG), CSIC/University of Salamanca, 37007 Salamanca, Spain.
- Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, 37007 Salamanca, Spain.
| | - Sergio Moreno
- Institute of Functional Biology and Genomics (IBFG), CSIC/University of Salamanca, 37007 Salamanca, Spain.
- Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, 37007 Salamanca, Spain.
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29
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Abstract
To respond to the changing environment, cells must be able to sense external conditions. This is important for many processes including growth, mating, the expression of virulence factors, and several other regulatory effects. Nutrient sensing at the plasma membrane is mediated by different classes of membrane proteins that activate downstream signaling pathways: nontransporting receptors, transceptors, classical and nonclassical G-protein-coupled receptors, and the newly defined extracellular mucin receptors. Nontransporting receptors have the same structure as transport proteins, but have lost the capacity to transport while gaining a receptor function. Transceptors are transporters that also function as a receptor, because they can rapidly activate downstream signaling pathways. In this review, we focus on these four types of fungal membrane proteins. We mainly discuss the sensing mechanisms relating to sugars, ammonium, and amino acids. Mechanisms for other nutrients, such as phosphate and sulfate, are discussed briefly. Because the model yeast Saccharomyces cerevisiae has been the most studied, especially regarding these nutrient-sensing systems, each subsection will commence with what is known in this species.
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30
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Abstract
Cell size is amenable by genetic and environmental factors. The highly conserved nutrient-responsive Target of Rapamycin (TOR) signaling pathway regulates cellular metabolic status and growth in response to numerous inputs. Timing and duration of TOR pathway activity is pivotal for both cell mass built up as well as cell cycle progression and is controlled and fine-tuned by the abundance and quality of nutrients, hormonal signals, growth factors, stress, and oxygen. TOR kinases function within two functionally and structurally discrete multiprotein complexes, TORC1 and TORC2, that are implicated in temporal and spatial control of cell size and growth respectively; however, recent data indicate that such functional distinctions are much more complex. Here, we briefly review roles of the two complexes in cellular growth and cytoarchitecture in various experimental model systems.
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Affiliation(s)
- Suam Gonzalez
- School of Health, Sport and Bioscience, University of East LondonLondon, United Kingdom
| | - Charalampos Rallis
- School of Health, Sport and Bioscience, University of East LondonLondon, United Kingdom
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