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Zemlianski V, Marešová A, Princová J, Holič R, Häsler R, Ramos Del Río MJ, Lhoste L, Zarechyntsava M, Převorovský M. Nitrogen availability is important for preventing catastrophic mitosis in fission yeast. J Cell Sci 2024; 137:jcs262196. [PMID: 38780300 DOI: 10.1242/jcs.262196] [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: 04/10/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024] Open
Abstract
Mitosis is a crucial stage in the cell cycle, controlled by a vast network of regulators responding to multiple internal and external factors. The fission yeast Schizosaccharomyces pombe demonstrates catastrophic mitotic phenotypes due to mutations or drug treatments. One of the factors provoking catastrophic mitosis is a disturbed lipid metabolism, resulting from, for example, mutations in the acetyl-CoA/biotin carboxylase (cut6), fatty acid synthase (fas2, also known as lsd1) or transcriptional regulator of lipid metabolism (cbf11) genes, as well as treatment with inhibitors of fatty acid synthesis. It has been previously shown that mitotic fidelity in lipid metabolism mutants can be partially rescued by ammonium chloride supplementation. In this study, we demonstrate that mitotic fidelity can be improved by multiple nitrogen sources. Moreover, this improvement is not limited to lipid metabolism disturbances but also applies to a number of unrelated mitotic mutants. Interestingly, the partial rescue is not achieved by restoring the lipid metabolism state, but rather indirectly. Our results highlight a novel role for nitrogen availability in mitotic fidelity.
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Affiliation(s)
- Viacheslav Zemlianski
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - Anna Marešová
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - Jarmila Princová
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - Roman Holič
- Centre of Biosciences SAS, Institute of Animal Biochemistry and Genetics, Dúbravská cesta 9, 840 05 Bratislava, Slovak Republic
| | - Robert Häsler
- Center for Inflammatory Skin Diseases, Department of Dermatology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Rosalind-Franklin-Straße 9, 24105 Kiel, Germany
| | - Manuel José Ramos Del Río
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - Laurane Lhoste
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - Maryia Zarechyntsava
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - Martin Převorovský
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
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Marešová A, Oravcová M, Rodríguez-López M, Hradilová M, Zemlianski V, Häsler R, Hernández P, Bähler J, Převorovský M. Critical importance of DNA binding for CSL protein functions in fission yeast. J Cell Sci 2024; 137:jcs261568. [PMID: 38482739 DOI: 10.1242/jcs.261568] [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: 08/22/2023] [Accepted: 03/07/2024] [Indexed: 05/01/2024] Open
Abstract
CSL proteins [named after the homologs CBF1 (RBP-Jκ in mice), Suppressor of Hairless and LAG-1] are conserved transcription factors found in animals and fungi. In the fission yeast Schizosaccharomyces pombe, they regulate various cellular processes, including cell cycle progression, lipid metabolism and cell adhesion. CSL proteins bind to DNA through their N-terminal Rel-like domain and central β-trefoil domain. Here, we investigated the importance of DNA binding for CSL protein functions in fission yeast. We created CSL protein mutants with disrupted DNA binding and found that the vast majority of CSL protein functions depend on intact DNA binding. Specifically, DNA binding is crucial for the regulation of cell adhesion, lipid metabolism, cell cycle progression, long non-coding RNA expression and genome integrity maintenance. Interestingly, perturbed lipid metabolism leads to chromatin structure changes, potentially linking lipid metabolism to the diverse phenotypes associated with CSL protein functions. Our study highlights the critical role of DNA binding for CSL protein functions in fission yeast.
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Affiliation(s)
- Anna Marešová
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - Martina Oravcová
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - María Rodríguez-López
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Miluše Hradilová
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czechia
| | - Viacheslav Zemlianski
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
| | - Robert Häsler
- Center for Inflammatory Skin Diseases, Department of Dermatology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Rosalind-Franklin-Straße 9, 24105 Kiel, Germany
| | - Pablo Hernández
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Jürg Bähler
- Institute of Healthy Ageing and Department of Genetics, Evolution and Environment , University College London, Gower Street, London WC1E 6BT, UK
| | - Martin Převorovský
- Department of Cell Biology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czechia
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Lam UTF, Nguyen TTT, Raechell R, Yang J, Singer H, Chen ES. A Normalization Protocol Reduces Edge Effect in High-Throughput Analyses of Hydroxyurea Hypersensitivity in Fission Yeast. Biomedicines 2023; 11:2829. [PMID: 37893202 PMCID: PMC10604075 DOI: 10.3390/biomedicines11102829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Edge effect denotes better growth of microbial organisms situated at the edge of the solid agar media. Although the precise reason underlying edge effect is unresolved, it is generally attributed to greater nutrient availability with less competing neighbors at the edge. Nonetheless, edge effect constitutes an unavoidable confounding factor that results in misinterpretation of cell fitness, especially in high-throughput screening experiments widely employed for genome-wide investigation using microbial gene knockout or mutant libraries. Here, we visualize edge effect in high-throughput high-density pinning arrays and report a normalization approach based on colony growth rate to quantify drug (hydroxyurea)-hypersensitivity in fission yeast strains. This normalization procedure improved the accuracy of fitness measurement by compensating cell growth rate discrepancy at different locations on the plate and reducing false-positive and -negative frequencies. Our work thus provides a simple and coding-free solution for a struggling problem in robotics-based high-throughput screening experiments.
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Affiliation(s)
- Ulysses Tsz-Fung Lam
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore; (U.T.-F.L.); (T.T.T.N.); (R.R.)
| | - Thi Thuy Trang Nguyen
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore; (U.T.-F.L.); (T.T.T.N.); (R.R.)
| | - Raechell Raechell
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore; (U.T.-F.L.); (T.T.T.N.); (R.R.)
| | - Jay Yang
- Singer Instruments, Roadwater, Watchet TA23 0RE, UK; (J.Y.); (H.S.)
| | - Harry Singer
- Singer Instruments, Roadwater, Watchet TA23 0RE, UK; (J.Y.); (H.S.)
| | - Ee Sin Chen
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore; (U.T.-F.L.); (T.T.T.N.); (R.R.)
- NUS Center for Cancer Research, National University of Singapore, Singapore 117599, Singapore
- NUS Synthetic Biology for Clinical & Technological Innovation (SynCTI), Life Science Institute, National University of Singapore, Singapore 117456, Singapore
- National University Health System (NUHS), Singapore 119228, Singapore
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Wu CC, Honda K, Kazuhito F. Current advances in alteration of fatty acid profile in Rhodotorula toruloides: a mini-review. World J Microbiol Biotechnol 2023; 39:234. [PMID: 37358633 PMCID: PMC10293357 DOI: 10.1007/s11274-023-03595-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/27/2023] [Indexed: 06/27/2023]
Abstract
Microbial lipids are considered promising and environmentally friendly substitutes for fossil fuels and plant-derived oils. They alleviate the depletion of limited petroleum storage and the decrement of arable lands resulting from the greenhouse effect. Microbial lipids derived from oleaginous yeasts provide fatty acid profiles similar to plant-derived oils, which are considered as sustainable and alternative feedstocks for use in the biofuel, cosmetics, and food industries. Rhodotorula toruloides is an intriguing oleaginous yeast strain that can accumulate more than 70% of its dry biomass as lipid content. It can utilize a wide range of substrates, including low-cost sugars and industrial waste. It is also robust against various industrial inhibitors. However, precise control of the fatty acid profile of the lipids produced by R. toruloides is essential for broadening its biotechnological applications. This mini-review describes recent progress in identifying fatty synthesis pathways and consolidated strategies used for specific fatty acid-rich lipid production via metabolic engineering, strain domestication. In addition, this mini-review summarized the effects of culture conditions on fatty acid profiles in R. toruloides. The perspectives and constraints of harnessing R. toruloides for tailored lipid production are also discussed in this mini-review.
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Affiliation(s)
- Chih-Chan Wu
- International Center for Biotechnology, Osaka University, 2-1 Yamada-Oka, Suita, Osaka, 565-0871, Japan
| | - Kohsuke Honda
- International Center for Biotechnology, Osaka University, 2-1 Yamada-Oka, Suita, Osaka, 565-0871, Japan
- Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Fujiyama Kazuhito
- International Center for Biotechnology, Osaka University, 2-1 Yamada-Oka, Suita, Osaka, 565-0871, Japan.
- Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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Princová J, Salat-Canela C, Daněk P, Marešová A, de Cubas L, Bähler J, Ayté J, Hidalgo E, Převorovský M. Perturbed fatty-acid metabolism is linked to localized chromatin hyperacetylation, increased stress-response gene expression and resistance to oxidative stress. PLoS Genet 2023; 19:e1010582. [PMID: 36626368 PMCID: PMC9870116 DOI: 10.1371/journal.pgen.1010582] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/23/2023] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
Oxidative stress is associated with cardiovascular and neurodegenerative diseases, diabetes, cancer, psychiatric disorders and aging. In order to counteract, eliminate and/or adapt to the sources of stress, cells possess elaborate stress-response mechanisms, which also operate at the level of regulating transcription. Interestingly, it is becoming apparent that the metabolic state of the cell and certain metabolites can directly control the epigenetic information and gene expression. In the fission yeast Schizosaccharomyces pombe, the conserved Sty1 stress-activated protein kinase cascade is the main pathway responding to most types of stresses, and regulates the transcription of hundreds of genes via the Atf1 transcription factor. Here we report that fission yeast cells defective in fatty acid synthesis (cbf11, mga2 and ACC/cut6 mutants; FAS inhibition) show increased expression of a subset of stress-response genes. This altered gene expression depends on Sty1-Atf1, the Pap1 transcription factor, and the Gcn5 and Mst1 histone acetyltransferases, is associated with increased acetylation of histone H3 at lysine 9 in the corresponding gene promoters, and results in increased cellular resistance to oxidative stress. We propose that changes in lipid metabolism can regulate the chromatin and transcription of specific stress-response genes, which in turn might help cells to maintain redox homeostasis.
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Affiliation(s)
- Jarmila Princová
- Laboratory of Microbial Genomics, Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Clàudia Salat-Canela
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader, Barcelona, Spain
| | - Petr Daněk
- Laboratory of Microbial Genomics, Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Anna Marešová
- Laboratory of Microbial Genomics, Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Laura de Cubas
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader, Barcelona, Spain
| | - Jürg Bähler
- Institute of Healthy Ageing and Department of Genetics, Evolution & Environment, University College London, London, United Kingdom
| | - José Ayté
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader, Barcelona, Spain
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader, Barcelona, Spain
| | - Martin Převorovský
- Laboratory of Microbial Genomics, Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
- * E-mail:
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Zhang Y, Pang J, Liu S, Nie K, Deng L, Wang F, Liu J. Harnessing transcription factor Mga2 and fatty acid elongases to overproduce palmitoleic acid in Saccharomyces cerevisiae. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108402] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Cordova LT, Palmer CM, Alper HS. Shifting the distribution: modulation of the lipid profile in Yarrowia lipolytica via iron content. Appl Microbiol Biotechnol 2022; 106:1571-1581. [PMID: 35099573 DOI: 10.1007/s00253-022-11800-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/14/2022] [Accepted: 01/21/2022] [Indexed: 11/02/2022]
Abstract
Microbial fermentation offers a sustainable source of fuels, commodity chemicals, and pharmaceuticals, yet strain performance is influenced greatly by the growth media selected. Specifically, trace metals (e.g., iron, copper, manganese, zinc, and others) are critical for proper growth and enzymatic function within microorganisms yet are non-standardized across media formulation. In this work, the effect of trace metal supplementation on the lipid production profile of Yarrowia lipolytica was explored using tube scale fermentation followed by biomass and lipid characterization. Addition of iron (II) to the chemically defined Yeast Synthetic Complete (YSC) medium increased final optical density nearly twofold and lipid production threefold, while addition of copper (II) had no impact. Additionally, dose-responsive changes in lipid distribution were observed, with the percent of oleic acid increasing and stearic acid decreasing as initial iron concentration increased. These changes were reversible with subsequent iron-selective chelation. Use of rich Yeast Peptone Dextrose (YPD) medium enabled further increases in the production of two specialty oleochemicals ultimately reaching 63 and 47% of the lipid pool as α-linolenic acid and cyclopropane fatty acid, respectively, compared to YSC medium. Selective removal of iron (II) natively present in YPD medium decreased this oleochemical production, ultimately aligning the lipid profile with that of non-supplemented YSC medium. These results provide further insight into the proposed mechanisms for iron regulation in yeasts especially as these productions strains contain a mutant allele of the iron regulator, mga2. The work presented here also suggests a non-genetic method for control of the lipid profile in Y. lipolytica for use in diverse applications. KEY POINTS: • Iron supplementation increases cell density and lipid titer in Yarrowia lipolytica. • Iron addition reversibly alters lipid portfolio increasing linolenic acid. • Removal of iron from YPD media provides a link to enhanced oleochemical production.
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Affiliation(s)
- Lauren T Cordova
- McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 E Dean Keeton St. Stop C0400, Austin, TX, 78712, USA
| | - Claire M Palmer
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2500 Speedway Avenue, Austin, TX, 78712, USA
| | - Hal S Alper
- McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 E Dean Keeton St. Stop C0400, Austin, TX, 78712, USA. .,Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2500 Speedway Avenue, Austin, TX, 78712, USA.
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8
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Vítová M, Lanta V, Čížková M, Jakubec M, Rise F, Halskau Ø, Bišová K, Furse S. The biosynthesis of phospholipids is linked to the cell cycle in a model eukaryote. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158965. [PMID: 33992808 PMCID: PMC8202326 DOI: 10.1016/j.bbalip.2021.158965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 12/15/2022]
Abstract
The structural challenges faced by eukaryotic cells through the cell cycle are key for understanding cell viability and proliferation. We tested the hypothesis that the biosynthesis of structural lipids is linked to the cell cycle. If true, this would suggest that the cell's structure is important for progress through and perhaps even control of the cell cycle. Lipidomics (31P NMR and MS), proteomics (Western immunoblotting) and transcriptomics (RT-qPCR) techniques were used to profile the lipid fraction and characterise aspects of its metabolism at seven stages of the cell cycle of the model eukaryote, Desmodesmus quadricauda. We found considerable, transient increases in the abundance of phosphatidylethanolamine during the G1 phase (+35%, ethanolamine phosphate cytidylyltransferase increased 2·5×) and phosphatidylglycerol (+100%, phosphatidylglycerol synthase increased 22×) over the G1/pre-replication phase boundary. The relative abundance of phosphatidylcholine fell by ~35% during the G1. N-Methyl transferases for the conversion of phosphatidylethanolamine into phosphatidylcholine were not found in the de novo transcriptome profile, though a choline phosphate transferase was found, suggesting that the Kennedy pathway is the principal route for the synthesis of PC. The fatty acid profiles of the four most abundant lipids suggested that these lipids were not generally converted between one another. This study shows for the first time that there are considerable changes in the biosynthesis of the three most abundant phospholipid classes in the normal cell cycle of D. quadricauda, by margins large enough to elicit changes to the physical properties of membranes.
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Affiliation(s)
- Milada Vítová
- Laboratory of Cell Cycles of Algae (Laboratoř buněčných cyklů řas), Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradská 237, 379 01 Třeboň, Czech Republic
| | - Vojtěch Lanta
- Laboratory of Cell Cycles of Algae (Laboratoř buněčných cyklů řas), Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradská 237, 379 01 Třeboň, Czech Republic; Department of Functional Ecology, Institute of Botany of the Czech Academy of Sciences, Dukelská 135, 379 81 Třeboň, Czech Republic
| | - Mária Čížková
- Laboratory of Cell Cycles of Algae (Laboratoř buněčných cyklů řas), Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradská 237, 379 01 Třeboň, Czech Republic
| | - Martin Jakubec
- Department of Molecular Biology, University of Bergen, Thormøhlens gate 55, NO-5008 Bergen, Norway
| | - Frode Rise
- Department of Chemistry, Universitetet i Oslo, P. O. Box 1033, Blindern, NO-0315 Oslo, Norway
| | - Øyvind Halskau
- Department of Molecular Biology, University of Bergen, Thormøhlens gate 55, NO-5008 Bergen, Norway
| | - Kateřina Bišová
- Laboratory of Cell Cycles of Algae (Laboratoř buněčných cyklů řas), Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradská 237, 379 01 Třeboň, Czech Republic
| | - Samuel Furse
- Department of Molecular Biology, University of Bergen, Thormøhlens gate 55, NO-5008 Bergen, Norway; Core Metabolomics and Lipidomics Laboratory, Wellcome Trust-MRL Institute of Metabolic Science, University of Cambridge, Level 4, Pathology Building, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; Biological chemistry group, Jodrell laboratory, Royal Botanic Gardens Kew, United Kingdom.
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Sienski G, Narayan P, Bonner JM, Kory N, Boland S, Arczewska AA, Ralvenius WT, Akay L, Lockshin E, He L, Milo B, Graziosi A, Baru V, Lewis CA, Kellis M, Sabatini DM, Tsai LH, Lindquist S. APOE4 disrupts intracellular lipid homeostasis in human iPSC-derived glia. Sci Transl Med 2021; 13:eaaz4564. [PMID: 33658354 PMCID: PMC8218593 DOI: 10.1126/scitranslmed.aaz4564] [Citation(s) in RCA: 130] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 05/27/2020] [Accepted: 11/05/2020] [Indexed: 12/11/2022]
Abstract
The E4 allele of the apolipoprotein E gene (APOE) has been established as a genetic risk factor for many diseases including cardiovascular diseases and Alzheimer's disease (AD), yet its mechanism of action remains poorly understood. APOE is a lipid transport protein, and the dysregulation of lipids has recently emerged as a key feature of several neurodegenerative diseases including AD. However, it is unclear how APOE4 perturbs the intracellular lipid state. Here, we report that APOE4, but not APOE3, disrupted the cellular lipidomes of human induced pluripotent stem cell (iPSC)-derived astrocytes generated from fibroblasts of APOE4 or APOE3 carriers, and of yeast expressing human APOE isoforms. We combined lipidomics and unbiased genome-wide screens in yeast with functional and genetic characterization to demonstrate that human APOE4 induced altered lipid homeostasis. These changes resulted in increased unsaturation of fatty acids and accumulation of intracellular lipid droplets both in yeast and in APOE4-expressing human iPSC-derived astrocytes. We then identified genetic and chemical modulators of this lipid disruption. We showed that supplementation of the culture medium with choline (a soluble phospholipid precursor) restored the cellular lipidome to its basal state in APOE4-expressing human iPSC-derived astrocytes and in yeast expressing human APOE4 Our study illuminates key molecular disruptions in lipid metabolism that may contribute to the disease risk linked to the APOE4 genotype. Our study suggests that manipulating lipid metabolism could be a therapeutic approach to help alleviate the consequences of carrying the APOE4 allele.
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Affiliation(s)
- Grzegorz Sienski
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Priyanka Narayan
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
- Genetics and Biochemistry Branch, NIDDK, National Institutes of Health, Bethesda, MD 20814, USA
| | - Julia Maeve Bonner
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Nora Kory
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Sebastian Boland
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Aleksandra A Arczewska
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - William T Ralvenius
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Leyla Akay
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Elana Lockshin
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Liang He
- Duke University, Durham, NC 27708, USA
| | - Blerta Milo
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Agnese Graziosi
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Valeriya Baru
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Caroline A Lewis
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Manolis Kellis
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Koch Institute for Integrative Cancer Research and Massachusetts Institute of Technology, Department of Biology, Cambridge, MA 02139, USA
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA.
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Susan Lindquist
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
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10
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Scotchman E, Kume K, Navarro FJ, Nurse P. Identification of mutants with increased variation in cell size at onset of mitosis in fission yeast. J Cell Sci 2021; 134:jcs251769. [PMID: 33419777 PMCID: PMC7888708 DOI: 10.1242/jcs.251769] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/10/2020] [Indexed: 12/19/2022] Open
Abstract
Fission yeast cells divide at a similar cell length with little variation about the mean. This is thought to be the result of a control mechanism that senses size and corrects for any deviations by advancing or delaying onset of mitosis. Gene deletions that advance cells into mitosis at a smaller size or delay cells entering mitosis have led to the identification of genes potentially involved in this mechanism. However, the molecular basis of this control is still not understood. In this work, we have screened for genes that when deleted increase the variability in size of dividing cells. The strongest candidate identified in this screen was mga2 The mga2 deletion strain shows a greater variation in cell length at division, with a coefficient of variation (CV) of 15-24%, while the wild-type strain has a CV of 5-8%. Furthermore, unlike wild-type cells, the mga2 deletion cells are unable to correct cell size deviations within one cell cycle. We show that the mga2 gene genetically interacts with nem1 and influences the nuclear membrane and the nuclear-cytoplasmic transport of CDK regulators.
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Affiliation(s)
| | - Kazunori Kume
- Cell Cycle Laboratory, The Francis Crick Institute, London NW1 1AT, UK
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan
- Hiroshima Research Center for Healthy Aging (HiHA), Hiroshima University,Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | | | - Paul Nurse
- Cell Cycle Laboratory, The Francis Crick Institute, London NW1 1AT, UK
- Laboratory of Yeast Genetics and Cell Biology, Rockefeller University, New York, NY 10065, USA
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HapX, an Indispensable bZIP Transcription Factor for Iron Acquisition, Regulates Infection Initiation by Orchestrating Conidial Oleic Acid Homeostasis and Cytomembrane Functionality in Mycopathogen Beauveria bassiana. mSystems 2020; 5:5/5/e00695-20. [PMID: 33051379 PMCID: PMC7567583 DOI: 10.1128/msystems.00695-20] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Conidial maturation and germination are highly coupled physiological processes in filamentous fungi that are critical for the pathogenicity of mycopathogens. Compared to the mechanisms involved in conidial germination, those of conidial reserves during maturation are less understood. The insect-pathogenic fungus Beauveria bassiana, as a representative species of filamentous fungi, is important for applied and fundamental research. In addition to its conserved roles in fungal adaptation to iron status, the bZIP transcription factor HapX acts as a master regulator involved in conidial virulence and regulates fatty acid/lipid metabolism. Further investigation revealed that the Δ9-fatty acid desaturase gene (Ole1) is a direct downstream target of HapX. This study reveals the HapX-Ole1 pathway involved in the fatty acid/lipid accumulation associated with conidial maturation and provides new insights into the startup mechanism of infection caused by spores from pathogenic fungi. In pathogenic filamentous fungi, conidial germination not only is fundamental for propagation in the environment but is also a critical step of infection. In the insect mycopathogen Beauveria bassiana, we genetically characterized the role of the basic leucine zipper (bZIP) transcription factor HapX (BbHapX) in conidial nutrient reserves and pathogen-host interaction. Ablation of BbHapX resulted in an almost complete loss of virulence in the topical inoculation and intrahemocoel injection assays. Comparative transcriptomic analysis revealed that BbHapX is required for fatty acid (FA)/lipid metabolism, and biochemical analyses indicated that BbHapX loss caused a significant reduction in conidial FA contents. Exogenous oleic acid could partially or completely restore the impaired phenotypes of the ΔBbHapX mutant, including germination rate, membrane integrity, vegetative growth, and virulence. BbHapX mediates fungal iron acquisition which is not required for desaturation of stearic acid. Additionally, inactivation of the Δ9-fatty acid desaturase gene (BbOle1) generated defects similar to those of the ΔBbHapX mutant; oleic acid also had significant restorative effects on the defective phenotypes of the ΔBbOle1 mutant. A gel retarding assay revealed that BbHapX directly regulated the expression of BbOle1. Lipidomic analyses indicated that both BbHapX and BbOle1 contributed to the homeostasis of phospholipids with nonpolar tails derived from oleic acid; therefore, exogenous phospholipids could significantly restore membrane integrity. These data reveal that the HapX-Ole1 pathway contributes to conidial fatty acid/lipid reserves and that there are important links between the lipid biology and membrane functionality involved in the early stages of infection caused by B.bassiana. IMPORTANCE Conidial maturation and germination are highly coupled physiological processes in filamentous fungi that are critical for the pathogenicity of mycopathogens. Compared to the mechanisms involved in conidial germination, those of conidial reserves during maturation are less understood. The insect-pathogenic fungus Beauveria bassiana, as a representative species of filamentous fungi, is important for applied and fundamental research. In addition to its conserved roles in fungal adaptation to iron status, the bZIP transcription factor HapX acts as a master regulator involved in conidial virulence and regulates fatty acid/lipid metabolism. Further investigation revealed that the Δ9-fatty acid desaturase gene (Ole1) is a direct downstream target of HapX. This study reveals the HapX-Ole1 pathway involved in the fatty acid/lipid accumulation associated with conidial maturation and provides new insights into the startup mechanism of infection caused by spores from pathogenic fungi.
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Hapala I, Griac P, Holic R. Metabolism of Storage Lipids and the Role of Lipid Droplets in the Yeast Schizosaccharomyces pombe. Lipids 2020; 55:513-535. [PMID: 32930427 DOI: 10.1002/lipd.12275] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/14/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022]
Abstract
Storage lipids, triacylglycerols (TAG), and steryl esters (SE), are predominant constituents of lipid droplets (LD) in fungi. In several yeast species, metabolism of TAG and SE is linked to various cellular processes, including cell division, sporulation, apoptosis, response to stress, and lipotoxicity. In addition, TAG are an important source for the generation of value-added lipids for industrial and biomedical applications. The fission yeast Schizosaccharomyces pombe is a widely used unicellular eukaryotic model organism. It is a powerful tractable system used to study various aspects of eukaryotic cellular and molecular biology. However, the knowledge of S. pombe neutral lipids metabolism is quite limited. In this review, we summarize and discuss the current knowledge of the homeostasis of storage lipids and of the role of LD in the fission yeast S. pombe with the aim to stimulate research of lipid metabolism and its connection with other essential cellular processes. We also discuss the advantages and disadvantages of fission yeast in lipid biotechnology and recent achievements in the use of S. pombe in the biotechnological production of valuable lipid compounds.
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Affiliation(s)
- Ivan Hapala
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
| | - Peter Griac
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
| | - Roman Holic
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
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CgCmk1 Activates CgRds2 To Resist Low-pH Stress in Candida glabrata. Appl Environ Microbiol 2020; 86:AEM.00302-20. [PMID: 32245757 DOI: 10.1128/aem.00302-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/27/2020] [Indexed: 02/07/2023] Open
Abstract
In Candida glabrata, the transcription factor CgRds2 has been previously characterized as a regulator of glycerophospholipid metabolism, playing a crucial role in the response to osmotic stress. Here, we report that CgRds2 is also involved in the response to pH 2.0 stress. At pH 2.0, the deletion of CgRDS2 led to reduced cell growth and survival, by 33% and 57%, respectively, compared with those of the wild-type strain. These adverse phenotypes resulted from the downregulation of genes related to energy metabolism in the Cgrds2Δ strain at pH 2.0, which led to a 34% reduction of the intracellular ATP content and a 24% decrease in membrane permeability. In contrast, the overexpression of CgRDS2 rescued the growth defect of the Cgrds2Δ strain and increased cell survival at pH 2.0 by 17% compared with that of the wild-type strain, and this effect was accompanied by significant increases in ATP content and membrane permeability, by 42% and 19%, respectively. Furthermore, we found that the calcium/calmodulin-dependent protein kinase (CaMK) CgCmk1 physically interacts with the PAS domain of CgRds2, and CgCmk1 is required for CgRds2 activation and translocation from the cytoplasm to the nucleus under pH 2.0 stress. Moreover, CgCmk1 is critical for CgRds2 function in resistance to pH 2.0 stress, because cells of the Cgrds2-pas strain with a disrupted CgCmk1-CgRds2 interaction exhibited impaired energy metabolism and membrane permeability at pH 2.0. Therefore, our results indicate that CgCmk1 positively regulates CgRds2 and suggest that they promote resistance to low-pH stress by enhancing energy metabolism and membrane permeability in C. glabrata IMPORTANCE An acidic environment is the main problem in the production of organic acids in C. glabrata The present study reports that the calcium/calmodulin-dependent protein kinase CgCmk1 positively regulates CgRds2 to increase intracellular ATP content, membrane permeability, and resistance to low-pH stress. Hence, the transcription factor CgRds2 may be a potential target for improving the acid stress tolerance of C. glabrata during the fermentation of organic acids. The present study also establishes a new link between the calcium signaling pathway and energy metabolism.
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Turning the Oxygen Dial: Balancing the Highs and Lows. Trends Cell Biol 2020; 30:516-536. [PMID: 32386878 DOI: 10.1016/j.tcb.2020.04.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/02/2020] [Accepted: 04/08/2020] [Indexed: 02/06/2023]
Abstract
Oxygen is both vital and toxic to life. Molecular oxygen is the most used substrate in the human body and is required for several hundred diverse biochemical reactions. The discovery of the PHD-HIF-pVHL system revolutionized our fundamental understanding of oxygen sensing and cellular adaptations to hypoxia. It deepened our knowledge of the biochemical underpinnings of numerous diseases, ranging from anemia to cancer. Cellular dysfunction and tissue pathology can result from a mismatch of oxygen supply and demand. Recent work has shown that mitochondrial disease models display tissue hyperoxia and that disease pathology can be reversed by normalization of excess oxygen, suggesting that certain disease states can potentially be treated by modulating oxygen levels. In this review, we describe cellular and organismal mechanisms of oxygen sensing and adaptation. We provide a revitalized framework for understanding pathologies of too little or too much oxygen.
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Makarova M, Peter M, Balogh G, Glatz A, MacRae JI, Lopez Mora N, Booth P, Makeyev E, Vigh L, Oliferenko S. Delineating the Rules for Structural Adaptation of Membrane-Associated Proteins to Evolutionary Changes in Membrane Lipidome. Curr Biol 2020; 30:367-380.e8. [PMID: 31956022 PMCID: PMC6997885 DOI: 10.1016/j.cub.2019.11.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/31/2019] [Accepted: 11/13/2019] [Indexed: 01/01/2023]
Abstract
Membrane function is fundamental to life. Each species explores membrane lipid diversity within a genetically predefined range of possibilities. How membrane lipid composition in turn defines the functional space available for evolution of membrane-centered processes remains largely unknown. We address this fundamental question using related fission yeasts Schizosaccharomyces pombe and Schizosaccharomyces japonicus. We show that, unlike S. pombe that generates membranes where both glycerophospholipid acyl tails are predominantly 16-18 carbons long, S. japonicus synthesizes unusual "asymmetrical" glycerophospholipids where the tails differ in length by 6-8 carbons. This results in stiffer bilayers with distinct lipid packing properties. Retroengineered S. pombe synthesizing the S.-japonicus-type phospholipids exhibits unfolded protein response and downregulates secretion. Importantly, our protein sequence comparisons and domain swap experiments support the hypothesis that transmembrane helices co-evolve with membranes, suggesting that, on the evolutionary scale, changes in membrane lipid composition may necessitate extensive adaptation of the membrane-associated proteome.
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Affiliation(s)
- Maria Makarova
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, Guy's Campus, London SE1 1UL, UK
| | - Maria Peter
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged 6726, Hungary
| | - Gabor Balogh
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged 6726, Hungary
| | - Attila Glatz
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged 6726, Hungary
| | - James I MacRae
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nestor Lopez Mora
- Department of Chemistry, King's College London, Britannia House, London SE1 1DB, UK
| | - Paula Booth
- Department of Chemistry, King's College London, Britannia House, London SE1 1DB, UK
| | - Eugene Makeyev
- MRC Centre for Developmental Neurobiology, King's College London, Guy's Campus, London SE1 1UL, UK
| | - Laszlo Vigh
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged 6726, Hungary
| | - Snezhana Oliferenko
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, Guy's Campus, London SE1 1UL, UK.
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16
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Holič R, Pokorná L, Griač P. Metabolism of phospholipids in the yeast
Schizosaccharomyces pombe. Yeast 2019; 37:73-92. [DOI: 10.1002/yea.3451] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 12/28/2022] Open
Affiliation(s)
- Roman Holič
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
| | - Lucia Pokorná
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
| | - Peter Griač
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
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Xia Z, Zhou X, Li J, Li L, Ma Y, Wu Y, Huang Z, Li X, Xu P, Xue M. Multiple-Omics Techniques Reveal the Role of Glycerophospholipid Metabolic Pathway in the Response of Saccharomyces cerevisiae Against Hypoxic Stress. Front Microbiol 2019; 10:1398. [PMID: 31316482 PMCID: PMC6610297 DOI: 10.3389/fmicb.2019.01398] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/04/2019] [Indexed: 11/13/2022] Open
Abstract
Although the biological processes of organism under hypoxic stress had been elucidated, the whole physiological changes of Saccharomyces cerevisiae are still unclear. In this work, we investigated the changes of biological process of S. cerevisiae under hypoxia by the methods of transcriptomics, proteomics, metabolomics, and bioinformatics. The results showed that the expression of a total of 1017 mRNA in transcriptome, 213 proteins in proteome, and 51 metabolites in metabolome had been significantly changed between the hypoxia and normoxia conditions. Moreover, based on the integration of system-omics data, we found that the carbohydrate, amino acids, fatty acid biosynthesis, lipid metabolic pathway, and oxidative phosphorylation were significantly changed in hypoxic stress. Among these pathways, the glycerophospholipid metabolic pathway was remarkably up-regulated from the mRNA, protein, and metabolites levels under hypoxic stress, and the expression of relevant mRNA was also confirmed by the qPCR. The metabolites of glycerophospholipid pathway such as phosphatidylcholine, phosphatidylethanolamine, phosphoinositide, and phosphatidic acids probably maintained the stability of cell membranes against hypoxic stress to relieve the cell injury, and kept S. cerevisiae survive with energy production. These findings in the hypoxic omics and integrated networks provide very useful information for further exploring the molecular mechanism of hypoxic stress.
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Affiliation(s)
- Zhengchao Xia
- Department of Pharmacology, Beijing Laboratory for Biomedical Detection Technology and Instrument, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Xuelin Zhou
- Department of Pharmacology, Beijing Laboratory for Biomedical Detection Technology and Instrument, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Jingyi Li
- Department of Pharmacology, Beijing Laboratory for Biomedical Detection Technology and Instrument, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Beijing Tropical Medicine Research Institute, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Lei Li
- Central Laboratory, Capital Medical University, Beijing, China
| | - Yi Ma
- Department of Pharmacology, Beijing Laboratory for Biomedical Detection Technology and Instrument, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Yi Wu
- Department of Pharmacology, Beijing Laboratory for Biomedical Detection Technology and Instrument, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Zhong Huang
- Health Branch College, Lanzhou Modern Vocational College, Lanzhou, China
| | - Xiaorong Li
- Department of Pharmacology, Beijing Laboratory for Biomedical Detection Technology and Instrument, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Pingxiang Xu
- Department of Pharmacology, Beijing Laboratory for Biomedical Detection Technology and Instrument, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Ming Xue
- Department of Pharmacology, Beijing Laboratory for Biomedical Detection Technology and Instrument, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Beijing Engineering Research Center for Nerve System Drugs, Beijing, China
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18
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Covino R, Hummer G, Ernst R. Integrated Functions of Membrane Property Sensors and a Hidden Side of the Unfolded Protein Response. Mol Cell 2019; 71:458-467. [PMID: 30075144 DOI: 10.1016/j.molcel.2018.07.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/09/2018] [Accepted: 07/17/2018] [Indexed: 12/26/2022]
Abstract
Eukaryotic cells face the challenge of maintaining the complex composition of several coexisting organelles. The molecular mechanisms underlying the homeostasis of subcellular membranes and their adaptation during stress are only now starting to emerge. Here, we discuss three membrane property sensors of the endoplasmic reticulum (ER), namely OPI1, MGA2, and IRE1, each controlling a large cellular program impacting the lipid metabolic network. OPI1 coordinates the production of membrane and storage lipids, MGA2 regulates the production of unsaturated fatty acids required for membrane biogenesis, and IRE1 controls the unfolded protein response (UPR) to adjust ER size, protein folding, and the secretory capacity of the cell. Although these proteins use remarkably distinct sensing mechanisms, they are functionally connected via the ER membrane and cooperate to maintain membrane homeostasis. As a rationalization of the recently described mechanism of UPR activation by lipid bilayer stress, we propose that IRE1 can sense the protein-to-lipid ratio in the ER membrane to ensure a balanced production of membrane proteins and lipids.
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Affiliation(s)
- Roberto Covino
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany; Institute of Biophysics, Goethe University, 60438 Frankfurt am Main, Germany
| | - Robert Ernst
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str. 100, Gebäude 61.4, 66421 Homburg, Germany.
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Knockout of the SREBP system increases production of the polyketide FR901512 in filamentous fungal sp. No. 14919 and lovastatin in Aspergillus terreus ATCC20542. Appl Microbiol Biotechnol 2017; 102:1393-1405. [DOI: 10.1007/s00253-017-8685-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/27/2017] [Accepted: 11/29/2017] [Indexed: 12/19/2022]
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Abstract
Cellular lipid metabolism and homeostasis are controlled by sterol regulatory-element binding proteins (SREBPs). In addition to performing canonical functions in the transcriptional regulation of genes involved in the biosynthesis and uptake of lipids, genome-wide system analyses have revealed that these versatile transcription factors act as important nodes of convergence and divergence within biological signalling networks. Thus, they are involved in myriad physiological and pathophysiological processes, highlighting the importance of lipid metabolism in biology. Changes in cell metabolism and growth are reciprocally linked through SREBPs. Anabolic and growth signalling pathways branch off and connect to multiple steps of SREBP activation and form complex regulatory networks. In addition, SREBPs are implicated in numerous pathogenic processes such as endoplasmic reticulum stress, inflammation, autophagy and apoptosis, and in this way, they contribute to obesity, dyslipidaemia, diabetes mellitus, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, chronic kidney disease, neurodegenerative diseases and cancers. This Review aims to provide a comprehensive understanding of the role of SREBPs in physiology and pathophysiology at the cell, organ and organism levels.
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Affiliation(s)
- Hitoshi Shimano
- Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
- Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba 305-8577, Japan
- AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-0004, Japan
| | - Ryuichiro Sato
- AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-0004, Japan
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan
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Hagihara K, Kinoshita K, Ishida K, Hojo S, Kameoka Y, Satoh R, Takasaki T, Sugiura R. A genome-wide screen for FTY720-sensitive mutants reveals genes required for ROS homeostasis. MICROBIAL CELL 2017; 4:390-401. [PMID: 29234668 PMCID: PMC5722642 DOI: 10.15698/mic2017.12.601] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Fingolimod hydrochloride (FTY720), a sphingosine-1-phosphate (S1P) analogue, is an approved immune modulator for the treatment of multiple sclerosis (MS). Notably, in addition to its well-known mode of action as an S1P modulator, accumulating evidence suggests that FTY720 induces apoptosis in various cancer cells via reactive oxygen species (ROS) generation. Although the involvement of multiple signaling molecules, such as JNK (Jun N-terminal kinase), Akt (alpha serine/threonine-protein kinase) and Sphk has been reported, the exact mechanisms how FTY720 induces cell growth inhibition and the functional relationship between FTY720 and these signaling pathways remain elusive. Our previous reports using the fission yeast Schizosaccharomyces pombe as a model system to elucidate FTY720-mediated signaling pathways revealed that FTY720 induces an increase in intracellular Ca2+ concentrations and ROS generation, which resulted in the activation of the transcriptional responses downstream of Ca2+/calcineurin signaling and stress-activated MAPK signaling, respectively. Here, we performed a genome-wide screening for genes whose deletion induces FTY720-sensitive growth in S. pombe and identified 49 genes. These gene products are related to the biological processes involved in metabolic processes, transport, transcription, translation, chromatin organization, cytoskeleton organization and intracellular signal transduction. Notably, most of the FTY720-sensitive deletion cells exhibited NAC-remedial FTY720 sensitivities and dysregulated ROS homeostasis. Our results revealed a novel gene network involving ROS homeostasis and the possible mechanisms of the FTY720 toxicity.
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Affiliation(s)
- Kanako Hagihara
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka City, Osaka 577-8502, Japan
| | - Kanako Kinoshita
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka City, Osaka 577-8502, Japan
| | - Kouki Ishida
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka City, Osaka 577-8502, Japan
| | - Shihomi Hojo
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka City, Osaka 577-8502, Japan
| | - Yoshinori Kameoka
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka City, Osaka 577-8502, Japan
| | - Ryosuke Satoh
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka City, Osaka 577-8502, Japan
| | - Teruaki Takasaki
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka City, Osaka 577-8502, Japan
| | - Reiko Sugiura
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, 3-4-1 Kowakae, Higashi-Osaka City, Osaka 577-8502, Japan
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Clasen SJ, Shao W, Gu H, Espenshade PJ. Prolyl dihydroxylation of unassembled uS12/Rps23 regulates fungal hypoxic adaptation. eLife 2017; 6:28563. [PMID: 29083304 PMCID: PMC5690285 DOI: 10.7554/elife.28563] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 10/19/2017] [Indexed: 12/17/2022] Open
Abstract
The prolyl-3,4-dihydroxylase Ofd1 and nuclear import adaptor Nro1 regulate the hypoxic response in fission yeast by controlling activity of the sterol regulatory element-binding protein transcription factor Sre1. Here, we identify an extra-ribosomal function for uS12/Rps23 central to this regulatory system. Nro1 binds Rps23, and Ofd1 dihydroxylates Rps23 P62 in complex with Nro1. Concurrently, Nro1 imports Rps23 into the nucleus for assembly into 40S ribosomes. Low oxygen inhibits Ofd1 hydroxylase activity and stabilizes the Ofd1-Rps23-Nro1 complex, thereby sequestering Ofd1 from binding Sre1, which is then free to activate hypoxic gene expression. In vitro studies demonstrate that Ofd1 directly binds Rps23, Nro1, and Sre1 through a consensus binding sequence. Interestingly, Rps23 expression modulates Sre1 activity by changing the Rps23 substrate pool available to Ofd1. To date, oxygen is the only known signal to Sre1, but additional nutrient signals may tune the hypoxic response through control of unassembled Rps23 or Ofd1 activity. Animals, plants, and fungi need oxygen to release energy within their cells and for other chemical reactions. Enzymes that use oxygen typically become less active when less oxygen is available, and this makes them well suited to help cells sense oxygen. These enzymes include oxygenases, some of which modify proteins by adding oxygen to specific sites in a reaction called hydroxylation. Oxygenases control how mammals adapt to low levels of oxygen – a condition referred to as hypoxia. These enzymes achieve this by hydroxylating a protein – specifically a transcription factor – that turns on genes for survival in low oxygen. Cells quickly destroy the hydroxylated transcription factor but when oxygen is limiting, it remains unmodified. This means that, rather than being destroyed, the transcription factor binds DNA, and activates genes that keep the cells alive and growing in low oxygen. In fission yeast, an oxygenase called Ofd1 controls the activity of a transcription factor called Sre1. Yeast requires Sre1 to grow when oxygen is limiting. Exactly how Ofd1 regulates Sre1 is unknown, but the mechanism is different from that in mammals because regulation of gene expression does not need Sre1 to be hydroxylated. Now, Clasen et al. report that Ofd1 actually hydroxylates another protein called Rps23. This protein is one of about 80 that form the cell’s protein-building machinery, the ribosome. It turns out that, before Rps23 becomes part of the ribosome, it binds Ofd1 in a complex with other proteins. The multi-protein complex then acts to hydroxylate and transport Rps23 into the nucleus, where ribosomes are built and where the cell stores its DNA. When little oxygen is around, Ofd1 cannot hydroxylate Rps23. This stops the complex from falling apart and traps Ofd1 away from the transcription factor Sre1. When not bound by Ofd1, Sre1 is free to turn on genes that allow growth at low levels of oxygen. Finally, Clasen et al. show that more unassembled Rps23 means less Ofd1 is available to inhibit Sre1, which controls the yeast cell’s response to hypoxia. Humans have proteins similar to Ofd1 and Rps23. As such, this pathway for sensing oxygen in yeast may occur in humans too. Further work is now needed to explore if other enzymes that hydroxylate ribosomal proteins work in a similar way.
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Affiliation(s)
- Sara J Clasen
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Wei Shao
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - He Gu
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Peter J Espenshade
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, United States
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Burr R, Espenshade PJ. Oxygen-responsive transcriptional regulation of lipid homeostasis in fungi: Implications for anti-fungal drug development. Semin Cell Dev Biol 2017; 81:110-120. [PMID: 28851600 DOI: 10.1016/j.semcdb.2017.08.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 08/08/2017] [Accepted: 08/22/2017] [Indexed: 01/01/2023]
Abstract
Low oxygen adaptation is essential for aerobic fungi that must survive in varied oxygen environments. Pathogenic fungi in particular must adapt to the low oxygen host tissue environment in order to cause infection. Maintenance of lipid homeostasis is especially important for cell growth and proliferation, and is a highly oxygen-dependent process. In this review, we focus on recent advances in our understanding of the transcriptional regulation and coordination of the low oxygen response across fungal species, paying particular attention to pathogenic fungi. Comparison of lipid homeostasis pathways in these organisms suggests common mechanisms of transcriptional regulation and points toward untapped potential to target low oxygen adaptation in antifungal development.
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Affiliation(s)
- Risa Burr
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Peter J Espenshade
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Burr R, Ribbens D, Raychaudhuri S, Stewart EV, Ho J, Espenshade PJ. Dsc E3 ligase localization to the Golgi requires the ATPase Cdc48 and cofactor Ufd1 for activation of sterol regulatory element-binding protein in fission yeast. J Biol Chem 2017; 292:16333-16350. [PMID: 28821619 DOI: 10.1074/jbc.m117.802025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/08/2017] [Indexed: 11/06/2022] Open
Abstract
Sterol regulatory element-binding proteins (SREBPs) in the fission yeast Schizosaccharomyces pombe regulate lipid homeostasis and the hypoxic response under conditions of low sterol or oxygen availability. SREBPs are cleaved in the Golgi through the combined action of the Dsc E3 ligase complex, the rhomboid protease Rbd2, and the essential ATPases associated with diverse cellular activities (AAA+) ATPase Cdc48. The soluble SREBP N-terminal transcription factor domain is then released into the cytosol to enter the nucleus and regulate gene expression. Previously, we reported that Cdc48 binding to Rbd2 is required for Rbd2-mediated SREBP cleavage. Here, using affinity chromatography and mass spectrometry experiments, we identified Cdc48-binding proteins in S. pombe, generating a list of many previously unknown potential Cdc48-binding partners. We show that the established Cdc48 cofactor Ufd1 is required for SREBP cleavage but does not interact with the Cdc48-Rbd2 complex. Cdc48-Ufd1 is instead required at a step prior to Rbd2 function, during Golgi localization of the Dsc E3 ligase complex. Together, these findings demonstrate that two distinct Cdc48 complexes, Cdc48-Ufd1 and Cdc48-Rbd2, are required for SREBP activation and low-oxygen adaptation in S. pombe.
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Affiliation(s)
- Risa Burr
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Diedre Ribbens
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Sumana Raychaudhuri
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Emerson V Stewart
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Jason Ho
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Peter J Espenshade
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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Santomartino R, Riego-Ruiz L, Bianchi MM. Three, two, one yeast fatty acid desaturases: regulation and function. World J Microbiol Biotechnol 2017; 33:89. [PMID: 28390014 DOI: 10.1007/s11274-017-2257-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/31/2017] [Indexed: 01/01/2023]
Abstract
Fatty acid composition of biological membranes functionally adapts to environmental conditions by changing its composition through the activity of lipid biosynthetic enzymes, including the fatty acid desaturases. Three major desaturases are present in yeasts, responsible for the generation of double bonds in position C9-C10, C12-C13 and C15-C16 of the carbon backbone. In this review, we will report data addressed to define the functional role of basidiomycete and ascomycete yeast desaturase enzymes in response to various external signals and the regulation of the expression of their corresponding genes. Many yeast species have the complete set of three desaturases; however, only the Δ9 desaturase seems to be necessary and sufficient to ensure yeast viability. The evolutionary issue of this observation will be discussed.
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Affiliation(s)
- Rosa Santomartino
- Dip. di Biologia e Biotecnologie C. Darwin, Sapienza Università di Roma, p.le Aldo Moro 5, 00185, Rome, Italy
| | - Lina Riego-Ruiz
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), A.C., San Luis Potosí, Mexico
| | - Michele M Bianchi
- Dip. di Biologia e Biotecnologie C. Darwin, Sapienza Università di Roma, p.le Aldo Moro 5, 00185, Rome, Italy.
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Burr R, Stewart EV, Espenshade PJ. Coordinate Regulation of Yeast Sterol Regulatory Element-binding Protein (SREBP) and Mga2 Transcription Factors. J Biol Chem 2017; 292:5311-5324. [PMID: 28202541 DOI: 10.1074/jbc.m117.778209] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Indexed: 11/06/2022] Open
Abstract
The Mga2 and Sre1 transcription factors regulate oxygen-responsive lipid homeostasis in the fission yeast Schizosaccharomyces pombe in a manner analogous to the mammalian sterol regulatory element-binding protein (SREBP)-1 and SREBP-2 transcription factors. Mga2 and SREBP-1 regulate triacylglycerol and glycerophospholipid synthesis, whereas Sre1 and SREBP-2 regulate sterol synthesis. In mammals, a shared activation mechanism allows for coordinate regulation of SREBP-1 and SREBP-2. In contrast, distinct pathways activate fission yeast Mga2 and Sre1. Therefore, it is unclear whether and how these two related pathways are coordinated to maintain lipid balance in fission yeast. Previously, we showed that Sre1 cleavage is defective in the absence of mga2 Here, we report that this defect is due to deficient unsaturated fatty acid synthesis, resulting in aberrant membrane transport. This defect is recapitulated by treatment with the fatty acid synthase inhibitor cerulenin and is rescued by addition of exogenous unsaturated fatty acids. Furthermore, sterol synthesis inhibition blocks Mga2 pathway activation. Together, these data demonstrate that Sre1 and Mga2 are each regulated by the lipid product of the other transcription factor pathway, providing a source of coordination for these two branches of lipid synthesis.
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Affiliation(s)
- Risa Burr
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Emerson V Stewart
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Peter J Espenshade
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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Ballweg S, Ernst R. Control of membrane fluidity: the OLE pathway in focus. Biol Chem 2017; 398:215-228. [DOI: 10.1515/hsz-2016-0277] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/18/2016] [Indexed: 11/15/2022]
Abstract
Abstract
The maintenance of a fluid lipid bilayer is key for membrane integrity and cell viability. We are only beginning to understand how eukaryotic cells sense and maintain the characteristic lipid compositions and bulk membrane properties of their organelles. One of the key factors determining membrane fluidity and phase behavior is the proportion of saturated and unsaturated acyl chains in membrane lipids. Saccharomyces cerevisiae is an ideal model organism to study the regulation of the lipid acyl chain composition via the OLE pathway. The OLE pathway comprises all steps involved in the regulated mobilization of the transcription factors Mga2 and Spt23 from the endoplasmic reticulum (ER), which then drive the expression of OLE1 in the nucleus. OLE1 encodes for the essential Δ9-fatty acid desaturase Ole1 and is crucial for de novo biosynthesis of unsaturated fatty acids (UFAs) that are used as lipid building blocks. This review summarizes our current knowledge of the OLE pathway, the best-characterized, eukaryotic sense-and-control system regulating membrane lipid saturation, and identifies open questions to indicate future directions.
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Homeoviscous Adaptation and the Regulation of Membrane Lipids. J Mol Biol 2016; 428:4776-4791. [DOI: 10.1016/j.jmb.2016.08.013] [Citation(s) in RCA: 207] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 11/23/2022]
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Převorovský M, Oravcová M, Zach R, Jordáková A, Bähler J, Půta F, Folk P. CSL protein regulates transcription of genes required to prevent catastrophic mitosis in fission yeast. Cell Cycle 2016; 15:3082-3093. [PMID: 27687771 DOI: 10.1080/15384101.2016.1235100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
For every eukaryotic cell to grow and divide, intricately coordinated action of numerous proteins is required to ensure proper cell-cycle progression. The fission yeast Schizosaccharomyces pombe has been instrumental in elucidating the fundamental principles of cell-cycle control. Mutations in S. pombe 'cut' (cell untimely torn) genes cause failed coordination between cell and nuclear division, resulting in catastrophic mitosis. Deletion of cbf11, a fission yeast CSL transcription factor gene, triggers a 'cut' phenotype, but the precise role of Cbf11 in promoting mitotic fidelity is not known. We report that Cbf11 directly activates the transcription of the acetyl-coenzyme A carboxylase gene cut6, and the biotin uptake/biosynthesis genes vht1 and bio2, with the former 2 implicated in mitotic fidelity. Cbf11 binds to a canonical, metazoan-like CSL response element (GTGGGAA) in the cut6 promoter. Expression of Cbf11 target genes shows apparent oscillations during the cell cycle using temperature-sensitive cdc25-22 and cdc10-M17 block-release experiments, but not with other synchronization methods. The penetrance of catastrophic mitosis in cbf11 and cut6 mutants is nutrient-dependent. We also show that drastic decrease in biotin availability arrests cell proliferation but does not cause mitotic defects. Taken together, our results raise the possibility that CSL proteins play conserved roles in regulating cell-cycle progression, and they could guide experiments into mitotic CSL functions in mammals.
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Affiliation(s)
- Martin Převorovský
- a Department of Cell Biology , Faculty of Science, Charles University in Prague , Prague , Czech Republic
| | - Martina Oravcová
- a Department of Cell Biology , Faculty of Science, Charles University in Prague , Prague , Czech Republic
| | - Róbert Zach
- a Department of Cell Biology , Faculty of Science, Charles University in Prague , Prague , Czech Republic
| | - Anna Jordáková
- a Department of Cell Biology , Faculty of Science, Charles University in Prague , Prague , Czech Republic
| | - Jürg Bähler
- b Research Department of Genetics , Evolution & Environment and UCL Cancer Institute, University College London , Gower Street, London , UK
| | - František Půta
- a Department of Cell Biology , Faculty of Science, Charles University in Prague , Prague , Czech Republic
| | - Petr Folk
- a Department of Cell Biology , Faculty of Science, Charles University in Prague , Prague , Czech Republic
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