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Alsayyah C, Singh MK, Morcillo-Parra MA, Cavellini L, Shai N, Schmitt C, Schuldiner M, Zalckvar E, Mallet A, Belgareh-Touzé N, Zimmer C, Cohen MM. Mitofusin-mediated contacts between mitochondria and peroxisomes regulate mitochondrial fusion. PLoS Biol 2024; 22:e3002602. [PMID: 38669296 PMCID: PMC11078399 DOI: 10.1371/journal.pbio.3002602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/08/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
Mitofusins are large GTPases that trigger fusion of mitochondrial outer membranes. Similarly to the human mitofusin Mfn2, which also tethers mitochondria to the endoplasmic reticulum (ER), the yeast mitofusin Fzo1 stimulates contacts between Peroxisomes and Mitochondria when overexpressed. Yet, the physiological significance and function of these "PerMit" contacts remain unknown. Here, we demonstrate that Fzo1 naturally localizes to peroxisomes and promotes PerMit contacts in physiological conditions. These contacts are regulated through co-modulation of Fzo1 levels by the ubiquitin-proteasome system (UPS) and by the desaturation status of fatty acids (FAs). Contacts decrease under low FA desaturation but reach a maximum during high FA desaturation. High-throughput genetic screening combined with high-resolution cellular imaging reveal that Fzo1-mediated PerMit contacts favor the transit of peroxisomal citrate into mitochondria. In turn, citrate enters the TCA cycle to stimulate the mitochondrial membrane potential and maintain efficient mitochondrial fusion upon high FA desaturation. These findings thus unravel a mechanism by which inter-organelle contacts safeguard mitochondrial fusion.
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Affiliation(s)
- Cynthia Alsayyah
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Sorbonne Université, CNRS, UMR8226, Institut de Biologie Physico-Chimique, Paris, France
| | - Manish K. Singh
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Sorbonne Université, CNRS, UMR8226, Institut de Biologie Physico-Chimique, Paris, France
- Institut Pasteur, Université Paris Cité, Imaging and Modeling Unit, F-75015 Paris, France
| | - Maria Angeles Morcillo-Parra
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Sorbonne Université, CNRS, UMR8226, Institut de Biologie Physico-Chimique, Paris, France
| | - Laetitia Cavellini
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Sorbonne Université, CNRS, UMR8226, Institut de Biologie Physico-Chimique, Paris, France
| | - Nadav Shai
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Christine Schmitt
- Ultrastructural BioImaging Core Facility, C2RT, Institut Pasteur, Université Paris Cité, Paris, France
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Einat Zalckvar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Adeline Mallet
- Ultrastructural BioImaging Core Facility, C2RT, Institut Pasteur, Université Paris Cité, Paris, France
| | - Naïma Belgareh-Touzé
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Sorbonne Université, CNRS, UMR8226, Institut de Biologie Physico-Chimique, Paris, France
| | - Christophe Zimmer
- Institut Pasteur, Université Paris Cité, Imaging and Modeling Unit, F-75015 Paris, France
- Rudolf Virchow Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany
| | - Mickaël M. Cohen
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Sorbonne Université, CNRS, UMR8226, Institut de Biologie Physico-Chimique, Paris, France
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2
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Yoshimoto H, Bogaki T. Mechanisms of production and control of acetate esters in yeasts. J Biosci Bioeng 2023; 136:261-269. [PMID: 37607842 DOI: 10.1016/j.jbiosc.2023.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 08/24/2023]
Abstract
Acetate esters, such as isoamyl acetate and ethyl acetate, are major aroma components of alcoholic beverages. They are produced through synthesis from acetyl CoA and the corresponding alcohol by alcohol acetyltransferase (AATase) with specific control of reaction factors, including unsaturated fatty acids and precursors, the percentage of nitrogen, and oxygen. However, the mechanisms by which these specific reaction factors affect acetate ester production remain largely unknown. The cellular mechanisms underlying the effects of these factors on acetate ester production were examined by purifying AATase from yeast, characterizing it, and cloning the ATF gene encoding AATase from sake yeast and bottom-fermenting yeast. Genetic and biochemical studies suggested that the decrease in acetate production with the addition of oxygen and unsaturated fatty acids was due to a decrease in enzyme synthesis resulting from transcriptional repression of the ATF1 gene, which is responsible for most of the AATase activity. Furthermore, these results suggest that expression of the ATF1 gene is intricately regulated by a number of transcriptional regulatory genes such as ROX1 and RAP1. Based on these results, the mechanism of ester regulation by oxygen, unsaturated fatty acids and precursors, and ratio of nitrogen source are becoming clearer from a molecular biological point of view. The physiological significance of ester production by yeast is then discussed. In this review, we summarize the studies on AATase, ATF gene, regulation of ester production, and physiological significance of acetate ester.
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Affiliation(s)
- Hiroyuki Yoshimoto
- Institute for Future Beverages, Research & Development Division, Kirin Holdings Company Limited, Technovilleage Center 3F, 1-17-1 Namamugi, Tsurumi-ku, Yokohama, Kanagawa 236-8628, Japan.
| | - Takayuki Bogaki
- General Research Laboratory, Ozeki Corporation, 4-9 Imazu Dezaike-cho, Nishinomiya, Hyogo 663-8227, Japan
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3
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Sosa Ponce ML, Remedios MH, Moradi-Fard S, Cobb JA, Zaremberg V. SIR telomere silencing depends on nuclear envelope lipids and modulates sensitivity to a lysolipid. J Cell Biol 2023; 222:e202206061. [PMID: 37042812 PMCID: PMC10103788 DOI: 10.1083/jcb.202206061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 11/29/2022] [Accepted: 03/24/2023] [Indexed: 04/13/2023] Open
Abstract
The nuclear envelope (NE) is important in maintaining genome organization. The role of lipids in communication between the NE and telomere regulation was investigated, including how changes in lipid composition impact gene expression and overall nuclear architecture. Yeast was treated with the non-metabolizable lysophosphatidylcholine analog edelfosine, known to accumulate at the perinuclear ER. Edelfosine induced NE deformation and disrupted telomere clustering but not anchoring. Additionally, the association of Sir4 at telomeres decreased. RNA-seq analysis showed altered expression of Sir-dependent genes located at sub-telomeric (0-10 kb) regions, consistent with Sir4 dispersion. Transcriptomic analysis revealed that two lipid metabolic circuits were activated in response to edelfosine, one mediated by the membrane sensing transcription factors, Spt23/Mga2, and the other by a transcriptional repressor, Opi1. Activation of these transcriptional programs resulted in higher levels of unsaturated fatty acids and the formation of nuclear lipid droplets. Interestingly, cells lacking Sir proteins displayed resistance to unsaturated-fatty acids and edelfosine, and this phenotype was connected to Rap1.
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Affiliation(s)
| | | | - Sarah Moradi-Fard
- Departments of Biochemistry and Molecular Biology and Oncology, Cumming School of Medicine, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Calgary, Canada
| | - Jennifer A. Cobb
- Departments of Biochemistry and Molecular Biology and Oncology, Cumming School of Medicine, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Calgary, Canada
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, Canada
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary, Calgary, Canada
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Fatty Acyl Coenzyme A Synthetase Fat1p Regulates Vacuolar Structure and Stationary-Phase Lipophagy in Saccharomyces cerevisiae. Microbiol Spectr 2023; 11:e0462522. [PMID: 36598223 PMCID: PMC9927365 DOI: 10.1128/spectrum.04625-22] [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: 01/05/2023] Open
Abstract
During yeast stationary phase, a single spherical vacuole (lysosome) is created by the fusion of several small ones. Moreover, the vacuolar membrane is reconstructed into two distinct microdomains. Little is known, however, about how cells maintain vacuolar shape or regulate their microdomains. Here, we show that Fat1p, a fatty acyl coenzyme A (acyl-CoA) synthetase and fatty acid transporter, and not the synthetases Faa1p and Faa4p, is essential for vacuolar shape preservation, the development of vacuolar microdomains, and cell survival in stationary phase of the yeast Saccharomyces cerevisiae. Furthermore, Fat1p negatively regulates general autophagy in both log- and stationary-phase cells. In contrast, Fat1p promotes lipophagy, as the absence of FAT1 limits the entry of lipid droplets into the vacuole and reduces the degradation of liquid droplet (LD) surface proteins. Notably, supplementing with unsaturated fatty acids or overexpressing the desaturase Ole1p can reverse all aberrant phenotypes caused by FAT1 deficiency. We propose that Fat1p regulates stationary phase vacuolar morphology, microdomain differentiation, general autophagy, and lipophagy by controlling the degree of fatty acid saturation in membrane lipids. IMPORTANCE The ability to sense environmental changes and adjust the levels of cellular metabolism is critical for cell viability. Autophagy is a recycling process that makes the most of already-existing energy resources, and the vacuole/lysosome is the ultimate autophagic processing site in cells. Lipophagy is an autophagic process to select degrading lipid droplets. In yeast cells in stationary phase, vacuoles fuse and remodel their membranes to create a single spherical vacuole with two distinct membrane microdomains, which are required for yeast lipophagy. In this study, we discovered that Fat1p was capable of rapidly responding to changes in nutritional status and preserving cell survival by regulating membrane lipid saturation to maintain proper vacuolar morphology and the level of lipophagy in the yeast S. cerevisiae. Our findings shed light on how cells maintain vacuolar structure and promote the differentiation of vacuole surface microdomains for stationary-phase lipophagy.
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LsSpt23p is a regulator of triacylglycerol synthesis in the oleaginous yeast Lipomyces starkeyi. Appl Microbiol Biotechnol 2023; 107:1269-1284. [PMID: 36648525 DOI: 10.1007/s00253-023-12361-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/28/2022] [Accepted: 12/31/2022] [Indexed: 01/18/2023]
Abstract
The oleaginous yeast Lipomyces starkeyi has considerable potential in industrial application, since it can accumulate a large amount of triacylglycerol (TAG), which is produced from sugars under nitrogen limitation condition. However, the regulation of lipogenesis in L. starkeyi has not been investigated in depth. In this study, we compared the genome sequences of wild-type and mutants with increased TAG productivity, and identified a regulatory protein, LsSpt23p, which contributes to the regulation of TAG synthesis in L. starkeyi. L. starkeyi mutants overexpressing LsSPT23 had increased TAG productivity compared with the wild-type strain. Quantitative real-time PCR analysis showed that LsSpt23p upregulated the expression of GPD1, which encodes glycerol 3-phosphate dehydrogenase; the Kennedy pathway genes SCT1, SLC1, PAH1, DGA1, and DGA2; the citrate-mediated acyl-CoA synthesis pathway-related genes ACL1, ACL2, ACC1, FAS1, and FAS2; and OLE1, which encodes ∆9 fatty acid desaturase. Chromatin immunoprecipitation-quantitative PCR assays indicated that LsSpt23p acts as a direct regulator of SLC1 and PAH1, all the citrate-mediated acyl-CoA synthesis pathway-related genes, and OLE1. These results indicate that LsSpt23p regulates TAG synthesis. Phosphatidic acid is a common substrate of phosphatidic acid phosphohydrolase, which is used for TAG synthesis, and phosphatidate cytidylyltransferase 1 for phospholipid synthesis in the Kennedy pathway. LsSpt23p directly regulated PAH1 but did not affect the expression of CDS1, suggesting that the preferred route of carbon is the Pah1p-mediated TAG synthesis pathway under nitrogen limitation condition. The present study contributes to understanding the regulation of TAG synthesis, and will be valuable in future improvement of TAG productivity in oleaginous yeasts. KEY POINTS: LsSpt23p was identified as a positive regulator of TAG biosynthesis LsSPT23 overexpression enhanced TAG biosynthesis gene expression and TAG production LsSPT23M1108T overexpression mutant showed fivefold higher TAG production than control.
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6
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Huang LJ, Chen RH. Lipid saturation induces degradation of squalene epoxidase for sterol homeostasis and cell survival. Life Sci Alliance 2022; 6:6/1/e202201612. [PMID: 36368908 PMCID: PMC9652772 DOI: 10.26508/lsa.202201612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/24/2022] [Accepted: 10/25/2022] [Indexed: 11/13/2022] Open
Abstract
A fluid membrane containing a mix of unsaturated and saturated lipids is essential for life. However, it is unclear how lipid saturation might affect lipid homeostasis, membrane-associated proteins, and membrane organelles. Here, we generate temperature-sensitive mutants of the sole fatty acid desaturase gene OLE1 in the budding yeast Saccharomyces cerevisiae Using these mutants, we show that lipid saturation triggers the endoplasmic reticulum-associated degradation (ERAD) of squalene epoxidase Erg1, a rate-limiting enzyme in sterol biosynthesis, via the E3 ligase Doa10-Ubc7 complex. We identify the P469L mutation that abolishes the lipid saturation-induced ERAD of Erg1. Overexpressed WT or stable Erg1 mutants all mislocalize into foci in the ole1 mutant, whereas the stable Erg1 causes aberrant ER and severely compromises the growth of ole1, which are recapitulated by doa10 deletion. The toxicity of the stable Erg1 and doa10 deletion is due to the accumulation of lanosterol and misfolded proteins in ole1 Our study identifies Erg1 as a novel lipid saturation-regulated ERAD target, manifesting a close link between lipid homeostasis and proteostasis that maintains sterol homeostasis under the lipid saturation condition for cell survival.
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Affiliation(s)
| | - Rey-Huei Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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7
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Vujovic F, Hunter N, Farahani RM. Notch ankyrin domain: evolutionary rise of a thermodynamic sensor. Cell Commun Signal 2022; 20:66. [PMID: 35585601 PMCID: PMC9118731 DOI: 10.1186/s12964-022-00886-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 04/21/2022] [Indexed: 12/19/2022] Open
Abstract
Notch signalling pathway plays a key role in metazoan biology by contributing to resolution of binary decisions in the life cycle of cells during development. Outcomes such as proliferation/differentiation dichotomy are resolved by transcriptional remodelling that follows a switch from Notchon to Notchoff state, characterised by dissociation of Notch intracellular domain (NICD) from DNA-bound RBPJ. Here we provide evidence that transitioning to the Notchoff state is regulated by heat flux, a phenomenon that aligns resolution of fate dichotomies to mitochondrial activity. A combination of phylogenetic analysis and computational biochemistry was utilised to disclose structural adaptations of Notch1 ankyrin domain that enabled function as a sensor of heat flux. We then employed DNA-based micro-thermography to measure heat flux during brain development, followed by analysis in vitro of the temperature-dependent behaviour of Notch1 in mouse neural progenitor cells. The structural capacity of NICD to operate as a thermodynamic sensor in metazoans stems from characteristic enrichment of charged acidic amino acids in β-hairpins of the ankyrin domain that amplify destabilising inter-residue electrostatic interactions and render the domain thermolabile. The instability emerges upon mitochondrial activity which raises the perinuclear and nuclear temperatures to 50 °C and 39 °C, respectively, leading to destabilization of Notch1 transcriptional complex and transitioning to the Notchoff state. Notch1 functions a metazoan thermodynamic sensor that is switched on by intercellular contacts, inputs heat flux as a proxy for mitochondrial activity in the Notchon state via the ankyrin domain and is eventually switched off in a temperature-dependent manner. Video abstract
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Affiliation(s)
- Filip Vujovic
- IDR/Westmead Institute for Medical Research, Westmead, NSW, 2145, Australia.,School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, 2006, Australia
| | - Neil Hunter
- IDR/Westmead Institute for Medical Research, Westmead, NSW, 2145, Australia
| | - Ramin M Farahani
- IDR/Westmead Institute for Medical Research, Westmead, NSW, 2145, Australia. .,School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, 2006, Australia.
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8
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Lu Z, Wu Y, Chen Y, Chen X, Wu R, Lu Q, Chen D, Huang R. Role of spt23 in Saccharomyces cerevisiae thermal tolerance. Appl Microbiol Biotechnol 2022; 106:3691-3705. [PMID: 35476152 PMCID: PMC9151549 DOI: 10.1007/s00253-022-11920-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 11/02/2022]
Abstract
spt23 plays multiple roles in the thermal tolerance of budding yeast. spt23 regulates unsaturated lipid acid (ULA) content in the cell, which can then significantly affect cellular thermal tolerance. Being a Ty suppressor, spt23 can also interact with transposons (Tys) that are contributors to yeast's adaptive evolution. Nevertheless, few studies have investigated whether and how much spt23 can exert its regulatory functions through transposons. In this study, expression quantitative trait loci (eQTL) analysis was conducted with thermal-tolerant Saccharomyces cerevisiae strains, and spt23 was identified as one of the most important genes in mutants. spt23-overexpression (OE), deletion (Del), and integrative-expressed (IE) strains were constructed. Their heat tolerance, ethanol production, the expression level of key genes, and lipid acid contents in the cell membranes were measured. Furthermore, LTR (long terminal repeat)-amplicon sequencing was used to profile yeast transposon activities in the treatments. The results showed the Del type had a higher survival rate, biomass, and ethanol production, revealing negative correlations between spt23 expression levels and thermal tolerance. Total unsaturated lipid acid (TULA) contents in cell membranes were lower in the Del type, indicating its negative association with spt23 expression levels. The Del type resulted in the lower richness and higher evenness in LTR distributions, as well as higher transposon activities. The intersection of 3 gene sets and regression analysis revealed the relative weight of spt23's direct and TY-induced influence is about 4:3. These results suggested a heat tolerance model in which spt23 increases cell thermal tolerance through transcriptional regulation in addition to spt23-transposon triggered unknown responses. KEY POINTS: • spt23 is a key gene for heat tolerance, important for LA contents but not vital. • Deletion of spt23 decreases in yeast's LTR richness but not in evenness. • The relative weight of spt23's direct and TY-induced influence is about 4:3.
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Affiliation(s)
- Zhilong Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, Guangxi, 530004, People's Republic of China.,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, People's Republic of China.,National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, People's Republic of China
| | - Yanling Wu
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, People's Republic of China
| | - Ying Chen
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, People's Republic of China
| | - Xiaoling Chen
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, People's Republic of China
| | - Renzhi Wu
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, People's Republic of China
| | - Qi Lu
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, People's Republic of China
| | - Dong Chen
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, People's Republic of China
| | - Ribo Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning, Guangxi, 530004, People's Republic of China. .,College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, People's Republic of China. .,National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, People's Republic of China.
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9
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Camponeschi I, Montanari A, Beccaccioli M, Reverberi M, Mazzoni C, Bianchi MM. Light-Stress Response Mediated by the Transcription Factor KlMga2 in the Yeast Kluyveromyces lactis. Front Microbiol 2021; 12:705012. [PMID: 34335537 PMCID: PMC8317464 DOI: 10.3389/fmicb.2021.705012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/16/2021] [Indexed: 11/20/2022] Open
Abstract
In unicellular organisms like yeasts, which do not have specialized tissues for protection against environmental challenges, the presence of cellular mechanisms to respond and adapt to stress conditions is fundamental. In this work, we aimed to investigate the response to environmental light in Kluyveromyces lactis. Yeast lacks specialized light-sensing proteins; however, Saccharomyces cerevisiae has been reported to respond to light by increasing hydrogen peroxide level and triggering nuclear translocation of Msn2. This is a stress-sensitive transcription factor also present in K. lactis. To investigate light response in this yeast, we analyzed the different phenotypes generated by the deletion of the hypoxia responsive and lipid biosynthesis transcription factor KlMga2. Alterations in growth rate, mitochondrial functioning, ROS metabolism, and fatty acid biosynthesis provide evidence that light was a source of stress in K. lactis and that KlMga2 had a role in the light-stress response. The involvement of KlMsn2 and KlCrz1 in light stress was also explored, but the latter showed no function in this response.
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Affiliation(s)
- Ilaria Camponeschi
- Department of Biology and Biotechnology 'C. Darwin', Sapienza University of Rome, Rome, Italy
| | - Arianna Montanari
- Department of Biology and Biotechnology 'C. Darwin', Sapienza University of Rome, Rome, Italy
| | - Marzia Beccaccioli
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
| | - Massimo Reverberi
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
| | - Cristina Mazzoni
- Department of Biology and Biotechnology 'C. Darwin', Sapienza University of Rome, Rome, Italy
| | - Michele M Bianchi
- Department of Biology and Biotechnology 'C. Darwin', Sapienza University of Rome, Rome, Italy
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10
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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: 121] [Impact Index Per Article: 40.3] [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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11
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Rajakumar S, Vijayakumar R, Abhishek A, Selvam GS, Nachiappan V. Loss of ERAD bridging factor UBX2 modulates lipid metabolism and leads to ER stress-associated apoptosis during cadmium toxicity in Saccharomyces cerevisiae. Curr Genet 2020; 66:1003-1017. [DOI: 10.1007/s00294-020-01090-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/08/2020] [Accepted: 06/22/2020] [Indexed: 12/17/2022]
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12
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Jordá T, Romero AM, Perea-García A, Rozès N, Puig S. The lipid composition of yeast cells modulates the response to iron deficiency. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158707. [PMID: 32251724 DOI: 10.1016/j.bbalip.2020.158707] [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: 01/26/2020] [Revised: 03/18/2020] [Accepted: 03/31/2020] [Indexed: 01/19/2023]
Abstract
Iron is a vital micronutrient for all eukaryotes because it participates as a redox cofactor in multiple metabolic pathways, including lipid biosynthesis. In response to iron deficiency, the Saccharomyces cerevisiae iron-responsive transcription factor Aft1 accumulates in the nucleus and activates a set of genes that promote iron acquisition at the cell surface. In this study, we report that yeast cells lacking the transcription factor Mga2, which promotes the expression of the iron-dependent Δ9-fatty acid desaturase Ole1, display a defect in the activation of the iron regulon during the adaptation to iron limitation. Supplementation with exogenous unsaturated fatty acids (UFAs) or OLE1 expression rescues the iron regulon activation defect of mga2Δ cells. These observations and fatty acid measurements suggest that the mga2Δ defect in iron regulon expression is due to low UFA levels. Subcellular localization studies reveal that low UFAs cause a mislocalization of Aft1 protein to the vacuole upon iron deprivation that prevents its nuclear accumulation. These results indicate that Mga2 and Ole1 are essential to maintain the UFA levels required for Aft1-dependent activation of the iron regulon in response to iron deficiency, and directly connect the biosynthesis of fatty acids to the response to iron depletion.
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Affiliation(s)
- Tania Jordá
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), , Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Antonia María Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), , Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Ana Perea-García
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), , Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Nicolas Rozès
- Departament de Bioquímica i Biotecnología, Facultat d'Enologia, Universitat Rovira i Virgili, Tarragona, Spain
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), , Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain.
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13
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Ballweg S, Sezgin E, Doktorova M, Covino R, Reinhard J, Wunnicke D, Hänelt I, Levental I, Hummer G, Ernst R. Regulation of lipid saturation without sensing membrane fluidity. Nat Commun 2020; 11:756. [PMID: 32029718 PMCID: PMC7005026 DOI: 10.1038/s41467-020-14528-1] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 01/14/2020] [Indexed: 12/22/2022] Open
Abstract
Cells maintain membrane fluidity by regulating lipid saturation, but the molecular mechanisms of this homeoviscous adaptation remain poorly understood. We have reconstituted the core machinery for regulating lipid saturation in baker’s yeast to study its molecular mechanism. By combining molecular dynamics simulations with experiments, we uncover a remarkable sensitivity of the transcriptional regulator Mga2 to the abundance, position, and configuration of double bonds in lipid acyl chains, and provide insights into the molecular rules of membrane adaptation. Our data challenge the prevailing hypothesis that membrane fluidity serves as the measured variable for regulating lipid saturation. Rather, we show that Mga2 senses the molecular lipid-packing density in a defined region of the membrane. Our findings suggest that membrane property sensors have evolved remarkable sensitivities to highly specific aspects of membrane structure and dynamics, thus paving the way toward the development of genetically encoded reporters for such properties in the future. Cells maintain membrane fluidity by regulating lipid saturation, but the molecular mechanisms of this homeoviscous adaptation remain poorly understood. Here authors reconstituted the core machinery for regulating lipid saturation in baker’s yeast to directly characterize its response to defined membrane environments and uncover its mode-of-action.
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Affiliation(s)
- Stephanie Ballweg
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Kirrberger Strasse 100, Building 61.4, 66421, Homburg, Germany.,PZMS, Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany
| | - Erdinc Sezgin
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Milka Doktorova
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA
| | - Roberto Covino
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438, Frankfurt, Germany
| | - John Reinhard
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Kirrberger Strasse 100, Building 61.4, 66421, Homburg, Germany.,PZMS, Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany
| | - Dorith Wunnicke
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Inga Hänelt
- Institute of Biochemistry, Goethe University Frankfurt, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Ilya Levental
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Science Center, Houston, Texas, USA
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438, Frankfurt, Germany.,Institute of Biophysics, Goethe University Frankfurt, 60438, Frankfurt, Germany
| | - Robert Ernst
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Kirrberger Strasse 100, Building 61.4, 66421, Homburg, Germany. .,PZMS, Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421, Homburg, Germany.
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14
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de Mendoza D, Pilon M. Control of membrane lipid homeostasis by lipid-bilayer associated sensors: A mechanism conserved from bacteria to humans. Prog Lipid Res 2019; 76:100996. [DOI: 10.1016/j.plipres.2019.100996] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/25/2019] [Accepted: 06/28/2019] [Indexed: 12/31/2022]
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15
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Holt S, Miks MH, de Carvalho BT, Foulquié-Moreno MR, Thevelein JM. The molecular biology of fruity and floral aromas in beer and other alcoholic beverages. FEMS Microbiol Rev 2019; 43:193-222. [PMID: 30445501 PMCID: PMC6524682 DOI: 10.1093/femsre/fuy041] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 11/13/2018] [Indexed: 12/03/2022] Open
Abstract
Aroma compounds provide attractiveness and variety to alcoholic beverages. We discuss the molecular biology of a major subset of beer aroma volatiles, fruity and floral compounds, originating from raw materials (malt and hops), or formed by yeast during fermentation. We introduce aroma perception, describe the most aroma-active, fruity and floral compounds in fruits and their presence and origin in beer. They are classified into categories based on their functional groups and biosynthesis pathways: (1) higher alcohols and esters, (2) polyfunctional thiols, (3) lactones and furanones, and (4) terpenoids. Yeast and hops are the main sources of fruity and flowery aroma compounds in beer. For yeast, the focus is on higher alcohols and esters, and particularly the complex regulation of the alcohol acetyl transferase ATF1 gene. We discuss the release of polyfunctional thiols and monoterpenoids from cysteine- and glutathione-S-conjugated compounds and glucosides, respectively, the primary biological functions of the yeast enzymes involved, their mode of action and mechanisms of regulation that control aroma compound production. Furthermore, we discuss biochemistry and genetics of terpenoid production and formation of non-volatile precursors in Humulus lupulus (hops). Insight in these pathways provides a toolbox for creating innovative products with a diversity of pleasant aromas.
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Affiliation(s)
- Sylvester Holt
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee, Flanders, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Marta H Miks
- Carlsberg Research Laboratory, J.C. Jacobsens Gade 4, 1799 Copenhagen V, Denmark
- Faculty of Food Science, University of Warmia and Mazury in Olsztyn, Plac Cieszyński 1, 10–726 Olsztyn, Poland
| | - Bruna Trindade de Carvalho
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee, Flanders, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Maria R Foulquié-Moreno
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee, Flanders, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee, Flanders, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
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16
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Fun XH, Thibault G. Lipid bilayer stress and proteotoxic stress-induced unfolded protein response deploy divergent transcriptional and non-transcriptional programmes. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158449. [PMID: 31028913 DOI: 10.1016/j.bbalip.2019.04.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/14/2019] [Accepted: 04/22/2019] [Indexed: 12/13/2022]
Abstract
The unfolded protein response (UPR) is activated by endoplasmic reticulum (ER) stress and is designed to restore cellular homeostasis through multiple intracellular signalling pathways. In mammals, the UPR programme regulates the expression of hundreds of genes in response to signalling from ATF6, IRE1, and PERK. These three highly conserved stress sensors are activated by the accumulation of unfolded proteins within the ER. Alternatively, IRE1 and PERK sense generalised lipid bilayer stress (LBS) at the ER while ATF6 is activated by an increase of specific sphingolipids. As a result, the UPR supports cellular robustness as a broad-spectrum compensatory pathway that is achieved by deploying a tailored transcriptional programme adapted to the source of ER stress. This review summarises the current understanding of the three ER stress transducers in sensing proteotoxic stress and LBS. The plasticity of the UPR programme in the context of different sources of ER stress will also be discussed.
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Affiliation(s)
- Xiu Hui Fun
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Guillaume Thibault
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore.
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17
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Santomartino R, Camponeschi I, Polo G, Immesi A, Rinaldi T, Mazzoni C, Brambilla L, Bianchi MM. The hypoxic transcription factor KlMga2 mediates the response to oxidative stress and influences longevity in the yeast Kluyveromyces lactis. FEMS Yeast Res 2019; 19:5365995. [DOI: 10.1093/femsyr/foz020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 02/26/2019] [Indexed: 12/17/2022] Open
Abstract
ABSTRACT
Hypoxia is defined as the decline of oxygen availability, depending on environmental supply and cellular consumption rate. The decrease in O2 results in reduction of available energy in facultative aerobes. The response and/or adaptation to hypoxia and other changing environmental conditions can influence the properties and functions of membranes by modifying lipid composition. In the yeast Kluyveromyces lactis, the KlMga2 gene is a hypoxic regulatory factor for lipid biosynthesis—fatty acids and sterols—and is also involved in glucose signaling, glucose catabolism and is generally important for cellular fitness.
In this work we show that, in addition to the above defects, the absence of the KlMGA2 gene caused increased resistance to oxidative stress and extended lifespan of the yeast, associated with increased expression levels of catalase and SOD genes. We propose that KlMga2 might also act as a mediator of the oxidative stress response/adaptation, thus revealing connections among hypoxia, glucose signaling, fatty acid biosynthesis and ROS metabolism in K. lactis.
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Affiliation(s)
- Rosa Santomartino
- Department Biology and Biotechnology C. Darwin, University of Roma Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Ilaria Camponeschi
- Department Biology and Biotechnology C. Darwin, University of Roma Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Germano Polo
- Department Biology and Biotechnology C. Darwin, University of Roma Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Alessio Immesi
- Department Biology and Biotechnology C. Darwin, University of Roma Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Teresa Rinaldi
- Department Biology and Biotechnology C. Darwin, University of Roma Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Cristina Mazzoni
- Department Biology and Biotechnology C. Darwin, University of Roma Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Luca Brambilla
- Department Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
| | - Michele M Bianchi
- Department Biology and Biotechnology C. Darwin, University of Roma Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
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18
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Physiological Genomics of Multistress Resistance in the Yeast Cell Model and Factory: Focus on MDR/MXR Transporters. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2019; 58:1-35. [PMID: 30911887 DOI: 10.1007/978-3-030-13035-0_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The contemporary approach of physiological genomics is vital in providing the indispensable holistic understanding of the complexity of the molecular targets, signalling pathways and molecular mechanisms underlying the responses and tolerance to stress, a topic of paramount importance in biology and biotechnology. This chapter focuses on the toxicity and tolerance to relevant stresses in the cell factory and eukaryotic model yeast Saccharomyces cerevisiae. Emphasis is given to the function and regulation of multidrug/multixenobiotic resistance (MDR/MXR) transporters. Although these transporters have been considered drug/xenobiotic efflux pumps, the exact mechanism of their involvement in multistress resistance is still open to debate, as highlighted in this chapter. Given the conservation of transport mechanisms from S. cerevisiae to less accessible eukaryotes such as plants, this chapter also provides a proof of concept that validates the relevance of the exploitation of the experimental yeast model to uncover the function of novel MDR/MXR transporters in the plant model Arabidopsis thaliana. This knowledge can be explored for guiding the rational design of more robust yeast strains with improved performance for industrial biotechnology, for overcoming and controlling the deleterious activities of spoiling yeasts in the food industry, for developing efficient strategies to improve crop productivity in agricultural biotechnology.
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19
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Watcharawipas A, Watanabe D, Takagi H. Sodium Acetate Responses in Saccharomyces cerevisiae and the Ubiquitin Ligase Rsp5. Front Microbiol 2018; 9:2495. [PMID: 30459728 PMCID: PMC6232821 DOI: 10.3389/fmicb.2018.02495] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 09/28/2018] [Indexed: 12/31/2022] Open
Abstract
Recent studies have revealed the feasibility of sodium acetate as a potentially novel inhibitor/stressor relevant to the fermentation from neutralized lignocellulosic hydrolysates. This mini-review focuses on the toxicity of sodium acetate, which is composed of both sodium and acetate ions, and on the involved cellular responses that it elicits, particularly via the high-osmolarity glycerol (HOG) pathway, the Rim101 pathway, the P-type ATPase sodium pumps Ena1/2/5, and the ubiquitin ligase Rsp5 with its adaptors. Increased understanding of cellular responses to sodium acetate would improve our understanding of how cells respond not only to different stimuli but also to composite stresses induced by multiple components (e.g., sodium and acetate) simultaneously. Moreover, unraveling the characteristics of specific stresses under industrially related conditions and the cellular responses evoked by these stresses would be a key factor in the industrial yeast strain engineering toward the increased productivity of not only bioethanol but also advanced biofuels and valuable chemicals that will be in demand in the coming era of bio-based industry.
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Affiliation(s)
- Akaraphol Watcharawipas
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Daisuke Watanabe
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Hiroshi Takagi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
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20
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Huang M, Kao KC. Identifying novel genetic determinants for oxidative stress tolerance in Candida glabrata via adaptive laboratory evolution. Yeast 2018; 35:605-618. [PMID: 30141215 DOI: 10.1002/yea.3352] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/11/2018] [Accepted: 08/15/2018] [Indexed: 11/09/2022] Open
Abstract
Candida glabrata (C glabrata) is an important yeast of industrial and medical significance. Resistance to oxidative stress is an important trait affecting its robustness as a production host or virulence as a pathogenic agent, but current understanding of resistance mechanisms is still limited in this fungus. In this study, we rapidly evolved C glabrata population to adapt to oxidative challenge (from 80mM to 350mM of H2 O2 ) through short-term adaptive laboratory evolution. Adaptive mutants were isolated from evolved populations and subjected to phenotypic and omics analyses to identify potential mechanisms of tolerance to H2 O2 . Phenotypic characterizations revealed faster detoxification of H2 O2 and ability to initiate growth at a higher concentration of the oxidant in the isolated adaptive mutants compared with the wild type. Genome resequencing and genome-wide transcriptome analysis revealed multiple genetic determinants (eg, CAGL0E01243g, CAGL0F06831g, and CAGL0C00385g) that potentially contribute to enhanced H2 O2 resistance. Subsequent experimental verification confirmed that CgCth2 (CAGL0E01243g) and CgMga2 (CAGL0F06831g) are important in C glabrata tolerance to oxidative stress. Transcriptome profiling of adaptive mutants and bioinformatic analysis suggest that NADPH regeneration, modulation of membrane composition, cell wall remodeling, and/or global regulatory changes are involved in C glabrata tolerance to H2 O2 .
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Affiliation(s)
- Mian Huang
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas
| | - Katy C Kao
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas
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21
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Fantastic nuclear envelope herniations and where to find them. Biochem Soc Trans 2018; 46:877-889. [PMID: 30026368 DOI: 10.1042/bst20170442] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 12/19/2022]
Abstract
Morphological abnormalities of the bounding membranes of the nucleus have long been associated with human diseases from cancer to premature aging to neurodegeneration. Studies over the past few decades support that there are both cell intrinsic and extrinsic factors (e.g. mechanical force) that can lead to nuclear envelope 'herniations', a broad catch-all term that reveals little about the underlying molecular mechanisms that contribute to these morphological defects. While there are many genetic perturbations that could ultimately change nuclear shape, here, we focus on a subset of nuclear envelope herniations that likely arise as a consequence of disrupting physiological nuclear membrane remodeling pathways required to maintain nuclear envelope homeostasis. For example, stalling of the interphase nuclear pore complex (NPC) biogenesis pathway and/or triggering of NPC quality control mechanisms can lead to herniations in budding yeast, which are remarkably similar to those observed in human disease models of early-onset dystonia. By also examining the provenance of nuclear envelope herniations associated with emerging nuclear autophagy and nuclear egress pathways, we will provide a framework to help understand the molecular pathways that contribute to nuclear deformation.
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22
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Zhang M, Yu Q, Xiao C, Zhang K, Zhang D, Zhang B, Li M. Disruption of SPT23 results in increased heat sensitivity due to plasma membrane damage in Pichia pastoris. FEMS Yeast Res 2018; 18:4855941. [PMID: 29447393 DOI: 10.1093/femsyr/foy015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 02/10/2018] [Indexed: 11/14/2022] Open
Abstract
The ability to adapt to environmental changes is a necessary strategy for cell survival. Spt23 is responsible for regulation of Δ-9 desaturase expression in Pichia pastoris. Disruption of SPT23 leads to a remarkable decrease in cellular unsaturated fatty acids. In this study, we found that deletion of SPT23 resulted in growth defects under high temperature culture conditions and heat treatment induced the expression of SPT23. By measuring expression changes of heat shock proteins, protein levels and cellular localization of Hsf1, it was revealed that the sensitivity of spt23Δ to high temperature was independent of the heat shock response. Addition of the osmotic stabilizer sorbitol can restore the growth defects of spt23Δ under heat conditions. In addition, loss of SPT23 led to increased plasma membrane permeability, decreased plasma membrane integrity, depolarization, ergosterol synthesis defects and cell wall component disorder, which suggested that the sensitivity to heat treatment in spt23Δ was due to plasma membrane damage. Taken together, our results give new insights into the relationship between Spt23 and high temperature environmental stress.
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Affiliation(s)
- Meng Zhang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China.,CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qilin Yu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Chenpeng Xiao
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Kai Zhang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Dan Zhang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Biao Zhang
- Tianjin Traditional Chinese Medicine University, Tianjin 300193, China
| | - Mingchun Li
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin 300071, China
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23
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Romero AM, Jordá T, Rozès N, Martínez-Pastor MT, Puig S. Regulation of yeast fatty acid desaturase in response to iron deficiency. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:657-668. [PMID: 29627385 DOI: 10.1016/j.bbalip.2018.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/12/2018] [Accepted: 03/27/2018] [Indexed: 10/17/2022]
Abstract
Unsaturated fatty acids (UFA) are essential components of phospholipids that greatly contribute to the biophysical properties of cellular membranes. Biosynthesis of UFAs relies on a conserved family of iron-dependent fatty acid desaturases, whose representative in the model yeast Saccharomyces cerevisiae is Ole1. OLE1 expression is tightly regulated to adapt UFA biosynthesis and lipid bilayer properties to changes in temperature, and in UFA or oxygen availability. Despite iron deficiency being the most extended nutritional disorder worldwide, very little is known about the mechanisms and the biological relevance of fatty acid desaturases regulation in response to iron starvation. In this report, we show that endoplasmic reticulum-anchored transcription factor Mga2 activates OLE1 transcription in response to nutritional and genetic iron deficiencies. Cells lacking MGA2 display low UFA levels and do not grow under iron-limited conditions, unless UFAs are supplemented or OLE1 is overexpressed. The proteasome, E3 ubiquitin ligase Rsp5 and the Cdc48Npl4/Ufd1 complex are required for OLE1 activation during iron depletion. Interestingly, Mga2 also activates the transcription of its own mRNA in response to iron deficiency, hypoxia, low temperature and low UFAs. MGA2 up-regulation contributes to increase OLE1 expression in these situations. These results reveal the mechanism of OLE1 regulation when iron is scarce and identify the MGA2 auto-regulation as a potential activation strategy in multiple stresses.
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Affiliation(s)
- Antonia María Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Tania Jordá
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Nicolas Rozès
- Departament de Bioquímica i Biotecnología, Facultat d'Enologia, Universitat Rovira i Virgili, Tarragona, Spain
| | | | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain.
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24
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Graef M. Lipid droplet-mediated lipid and protein homeostasis in budding yeast. FEBS Lett 2018; 592:1291-1303. [PMID: 29397034 PMCID: PMC5947121 DOI: 10.1002/1873-3468.12996] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 01/24/2018] [Accepted: 01/25/2018] [Indexed: 12/25/2022]
Abstract
Lipid droplets are conserved specialized organelles that store neutral lipids. Our view on this unique organelle has evolved from a simple fat deposit to a highly dynamic and functionally diverse hub—one that mediates the buffering of fatty acid stress and the adaptive reshaping of lipid metabolism to promote membrane and organelle homeostasis and the integrity of central proteostasis pathways, including autophagy, which ensure stress resistance and cell survival. This Review will summarize the recent developments in the budding yeast Saccharomyces cerevisiae, as this model organism has been instrumental in deciphering the fundamental mechanisms and principles of lipid droplet biology and interconnecting lipid droplets with many unanticipated cellular functions applicable to many other cell systems.
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Affiliation(s)
- Martin Graef
- Max Planck Institute for Biology of Ageing, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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25
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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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26
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Zhang M, Yu Q, Liu Z, Liang C, Zhang B, Li M. UBX domain-containing proteins are involved in lipid homeostasis and stress responses in Pichia pastoris. Int J Biochem Cell Biol 2017; 90:136-144. [PMID: 28807601 DOI: 10.1016/j.biocel.2017.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 08/07/2017] [Accepted: 08/09/2017] [Indexed: 12/12/2022]
Abstract
Ubiquitin regulatory X (UBX) domain-containing proteins constitute a family of proteins and are substrate adaptors of AAA ATPase Cdc48. UBX proteins can bind to the N-terminal region of Cdc48 to perform endoplasmic reticulum associated protein degradation (ERAD). In this study, we identified two UBX domain-containing proteins, Ubx1 and Ubx2, in Pichia pastoris and found that the two proteins could recover the growth defect of Saccharomyces cerevisiae in ubx2Δ. Our results revealed that Ubx1 and Ubx2 play critical roles in synthesis of unsaturated fatty acids by affecting Spt23. In addition, the results demonstrated that both Ubx1 and Ubx2 are involved in lipid droplet formation and protein degradation. Deletion of UBX1 led to increased sensitivity to oxidative stress and disruption of UBX2 impaired cell viability under osmotic stress. The phenotypes of ubx1Δ+UBX2, ubx2Δ+UBX1 and ubx1Δubx2Δ and RNA-seq data suggested that Ubx1 and Ubx2 play different roles in cell functions, and the roles of Ubx1 may be more numerous than Ubx2. In summary, our findings provide new insights into the relationship between lipid homeostasis and cell functions in the oil-producing organism P. pastoris.
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Affiliation(s)
- Meng Zhang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
| | - Qilin Yu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
| | - Zhe Liu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
| | - Chen Liang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
| | - Biao Zhang
- Tianjin Traditional Chinese Medicine University, Tianjin, 300193, PR China.
| | - Mingchun Li
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
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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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29
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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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Lozano-Martínez P, Buey RM, Ledesma-Amaro R, Jiménez A, Revuelta JL. Engineering Ashbya gossypii strains for de novo lipid production using industrial by-products. Microb Biotechnol 2016; 10:425-433. [PMID: 28008713 PMCID: PMC5328814 DOI: 10.1111/1751-7915.12487] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 11/27/2022] Open
Abstract
Ashbya gossypii is a filamentous fungus that naturally overproduces riboflavin, and it is currently exploited for the industrial production of this vitamin. The utilization of A. gossypii for biotechnological applications presents important advantages such as the utilization of low-cost culture media, inexpensive downstream processing and a wide range of molecular tools for genetic manipulation, thus making A. gossypii a valuable biotechnological chassis for metabolic engineering. A. gossypii has been shown to accumulate high levels of lipids in oil-based culture media; however, the lipid biosynthesis capacity is rather limited when grown in sugar-based culture media. In this study, by altering the fatty acyl-CoA pool and manipulating the regulation of the main ∆9 desaturase gene, we have obtained A. gossypii strains with significantly increased (up to fourfold) de novo lipid biosynthesis using glucose as the only carbon source in the fermentation broth. Moreover, these strains were efficient biocatalysts for the conversion of carbohydrates from sugarcane molasses to biolipids, able to accumulate lipids up to 25% of its cell dry weight. Our results represent a proof of principle showing the promising potential of A. gossypii as a competitive microorganism for industrial biolipid production using cost-effective feed stocks.
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Affiliation(s)
- Patricia Lozano-Martínez
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Rubén M Buey
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Rodrigo Ledesma-Amaro
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Alberto Jiménez
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - José Luis Revuelta
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain
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31
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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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32
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Kojima R, Kajiura S, Sesaki H, Endo T, Tamura Y. Identification of multi-copy suppressors for endoplasmic reticulum-mitochondria tethering proteins in Saccharomyces cerevisiae. FEBS Lett 2016; 590:3061-70. [PMID: 27531107 DOI: 10.1002/1873-3468.12358] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 07/16/2016] [Accepted: 08/09/2016] [Indexed: 11/08/2022]
Abstract
In yeast, the endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) tethers the ER to mitochondria, but its primary function remains unclear. To gain insight into ERMES functions, we screened multi-copy suppressors of the growth-defective phenotype of mmm1∆ cells, which lack a core component of ERMES, and identified MCP1, MGA2, SPT23, and YGR250C (termed RIE1). Spt23 and Mga2 are homologous transcription factors known to activate transcription of the OLE1 gene, which encodes the fatty acid ∆9 desaturase. We found that Ole1 partially relieves the growth defects of ERMES-lacking cells, thus uncovering a relationship between fatty acid metabolism and ERMES functions.
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Affiliation(s)
- Rieko Kojima
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan.,Department of Material and Biological Science, Faculty of Science, Yamagata University, Japan
| | - Shu Kajiura
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan
| | - Hiromi Sesaki
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Toshiya Endo
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan. .,Faculty of Life Sciences, Kyoto Sangyo University, Japan. .,JST/CREST, Kyoto Sangyo University, Japan.
| | - Yasushi Tamura
- Department of Material and Biological Science, Faculty of Science, Yamagata University, Japan. .,Research Center for Materials Science, Nagoya University, Japan.
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33
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Trans 18-carbon monoenoic fatty acid has distinct effects from its isomeric cis fatty acid on lipotoxicity and gene expression in Saccharomyces cerevisiae. J Biosci Bioeng 2016; 123:33-38. [PMID: 27484790 DOI: 10.1016/j.jbiosc.2016.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 06/08/2016] [Accepted: 07/06/2016] [Indexed: 12/31/2022]
Abstract
Epidemiological studies have suggested that an excess intake of trans-unsaturated fatty acids increases the risk of coronary heart disease. However, the mechanisms of action of trans-unsaturated fatty acids in eukaryotic cells remain unclear. Since the budding yeast Saccharomyces cerevisiae can grow using fatty acids as the sole carbon source, it is a simple and suitable model organism for understanding the effects of trans-unsaturated fatty acids at the molecular and cellular levels. In this study, we compared the physiological effects of Δ9 cis and trans 18-carbon monoenoic fatty acids (oleic acid and elaidic acid) in yeast cells. The results obtained revealed that the two types have distinct effects on the expression of OLE1, which encodes Δ9 desaturase, and lipotoxicity in are1Δare2Δdga1Δlro1Δ and gat1Δ cells. Our results suggest that cis and trans 18-carbon monoenoic fatty acids exert different physiological effects in the regulation of gene expression and processing of excess fatty acids in yeast.
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34
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Covino R, Ballweg S, Stordeur C, Michaelis J, Puth K, Wernig F, Bahrami A, Ernst A, Hummer G, Ernst R. A Eukaryotic Sensor for Membrane Lipid Saturation. Mol Cell 2016; 63:49-59. [DOI: 10.1016/j.molcel.2016.05.015] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 04/12/2016] [Accepted: 05/11/2016] [Indexed: 12/22/2022]
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35
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Burr R, Stewart EV, Shao W, Zhao S, Hannibal-Bach HK, Ejsing CS, Espenshade PJ. Mga2 Transcription Factor Regulates an Oxygen-responsive Lipid Homeostasis Pathway in Fission Yeast. J Biol Chem 2016; 291:12171-83. [PMID: 27053105 DOI: 10.1074/jbc.m116.723650] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Indexed: 12/20/2022] Open
Abstract
Eukaryotic lipid synthesis is oxygen-dependent with cholesterol synthesis requiring 11 oxygen molecules and fatty acid desaturation requiring 1 oxygen molecule per double bond. Accordingly, organisms evaluate oxygen availability to control lipid homeostasis. The sterol regulatory element-binding protein (SREBP) transcription factors regulate lipid homeostasis. In mammals, SREBP-2 controls cholesterol biosynthesis, whereas SREBP-1 controls triacylglycerol and glycerophospholipid biosynthesis. In the fission yeast Schizosaccharomyces pombe, the SREBP-2 homolog Sre1 regulates sterol homeostasis in response to changing sterol and oxygen levels. However, notably missing is an SREBP-1 analog that regulates triacylglycerol and glycerophospholipid homeostasis in response to low oxygen. Consistent with this, studies have shown that the Sre1 transcription factor regulates only a fraction of all genes up-regulated under low oxygen. To identify new regulators of low oxygen adaptation, we screened the S. pombe nonessential haploid deletion collection and identified 27 gene deletions sensitive to both low oxygen and cobalt chloride, a hypoxia mimetic. One of these genes, mga2, is a putative transcriptional activator. In the absence of mga2, fission yeast exhibited growth defects under both normoxia and low oxygen conditions. Mga2 transcriptional targets were enriched for lipid metabolism genes, and mga2Δ cells showed disrupted triacylglycerol and glycerophospholipid homeostasis, most notably with an increase in fatty acid saturation. Indeed, addition of exogenous oleic acid to mga2Δ cells rescued the observed growth defects. Together, these results establish Mga2 as a transcriptional regulator of triacylglycerol and glycerophospholipid homeostasis in S. pombe, analogous to mammalian SREBP-1.
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Affiliation(s)
- Risa Burr
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
| | - Emerson V Stewart
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
| | - Wei Shao
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
| | - Shan Zhao
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
| | - Hans Kristian Hannibal-Bach
- the Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense, Denmark
| | - Christer S Ejsing
- the Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense, Denmark
| | - Peter J Espenshade
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
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36
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Bat-Ochir C, Kwak JY, Koh SK, Jeon MH, Chung D, Lee YW, Chae SK. The signal peptide peptidase SppA is involved in sterol regulatory element-binding protein cleavage and hypoxia adaptation in Aspergillus nidulans. Mol Microbiol 2016; 100:635-55. [PMID: 26822492 DOI: 10.1111/mmi.13341] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2016] [Indexed: 12/22/2022]
Abstract
Using forward genetics, we revealed that the signal peptide peptidase (SPP) SppA, an aspartyl protease involved in regulated intramembrane proteolysis (RIP), is essential for hypoxia adaptation in Aspergillus nidulans, as well as hypoxia-sensitive mutant alleles of a sterol regulatory element-binding protein (SREBP) srbA and the Dsc ubiquitin E3 ligase complex dscA-E. Both null and dead activity [D337A] mutants of sppA failed to grow in hypoxia, and the growth defect of ΔsppA was complemented by nuclear SrbA-N381 expression. Additionally, SppA interacted with SrbA in the endoplasmic reticulum, where SppA localized in normoxia and hypoxia. Expression of the truncated SrbA-N414 covering the SrbA sequence prior to the second transmembrane region rescued the growth of ΔdscA but not of ΔsppA in hypoxia. Unlike ΔdscA and ΔdscA;ΔsppA double mutants, in which SrbA cleavage was blocked, the molecular weight of cleaved SrbA increased in ΔsppA compared to the control strain in immunoblot analyses. Overall, our data demonstrate the sequential cleavage of SrbA by Dsc-linked proteolysis followed by SppA, proposing a new model of RIP for SREBP cleavage in fungal hypoxia adaptation. Furthermore, the function of SppA in hypoxia adaptation was consistent in Aspergillus fumigatus, suggesting the potential roles of SppA in fungal pathogenesis.
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Affiliation(s)
- Chinbayar Bat-Ochir
- Department of Biochemistry and Center for Fungal Pathogenesis, Pai Chai University, Daejeon, 34015, Republic of Korea
| | - Jun-Yong Kwak
- Department of Biochemistry and Center for Fungal Pathogenesis, Pai Chai University, Daejeon, 34015, Republic of Korea
| | - Sun-Ki Koh
- Department of Biochemistry and Center for Fungal Pathogenesis, Pai Chai University, Daejeon, 34015, Republic of Korea
| | - Mee-Hyang Jeon
- Department of Biochemistry and Center for Fungal Pathogenesis, Pai Chai University, Daejeon, 34015, Republic of Korea
| | - Dawoon Chung
- Department of Biochemistry and Center for Fungal Pathogenesis, Pai Chai University, Daejeon, 34015, Republic of Korea
| | - Yin-Won Lee
- Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, 08826, Republic of Korea
| | - Suhn-Kee Chae
- Department of Biochemistry and Center for Fungal Pathogenesis, Pai Chai University, Daejeon, 34015, Republic of Korea
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Prosser DC, Pannunzio AE, Brodsky JL, Thorner J, Wendland B, O'Donnell AF. α-Arrestins participate in cargo selection for both clathrin-independent and clathrin-mediated endocytosis. J Cell Sci 2015; 128:4220-34. [PMID: 26459639 PMCID: PMC4712785 DOI: 10.1242/jcs.175372] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 10/05/2015] [Indexed: 12/24/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) is a well-studied mechanism to internalize plasma membrane proteins; however, to endocytose such cargo, most eukaryotic cells also use alternative clathrin-independent endocytic (CIE) pathways, which are less well characterized. The budding yeast Saccharomyces cerevisiae, a widely used model for studying CME, was recently shown to have a CIE pathway that requires the GTPase Rho1, the formin Bni1, and their regulators. Nevertheless, in both yeast and mammalian cells, the mechanisms underlying cargo selection in CME and CIE are only beginning to be understood. For CME in yeast, particular α-arrestins contribute to recognition of specific cargos and promote their ubiquitylation by recruiting the E3 ubiquitin protein ligase Rsp5. Here, we show that the same α-arrestin–cargo pairs promote internalization through the CIE pathway by interacting with CIE components. Notably, neither expression of Rsp5 nor its binding to α-arrestins is required for CIE. Thus, α-arrestins are important for cargo selection in both the CME and CIE pathways, but function by distinct mechanisms in each pathway. Summary: In yeast, α-arrestins bind the Rho1 GTPase and regulate internalization of selective cargo through the clathrin-independent endocytic pathway.
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Affiliation(s)
- Derek C Prosser
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Anthony E Pannunzio
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jeremy Thorner
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA
| | - Beverly Wendland
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Allyson F O'Donnell
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA
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38
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Yeast Integral Membrane Proteins Apq12, Brl1, and Brr6 Form a Complex Important for Regulation of Membrane Homeostasis and Nuclear Pore Complex Biogenesis. EUKARYOTIC CELL 2015; 14:1217-27. [PMID: 26432634 DOI: 10.1128/ec.00101-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 10/01/2015] [Indexed: 11/20/2022]
Abstract
Proper functioning of intracellular membranes is critical for many cellular processes. A key feature of membranes is their ability to adapt to changes in environmental conditions by adjusting their composition so as to maintain constant biophysical properties, including fluidity and flexibility. Similar changes in the biophysical properties of membranes likely occur when intracellular processes, such as vesicle formation and fusion, require dramatic changes in membrane curvature. Similar modifications must also be made when nuclear pore complexes (NPCs) are constructed within the existing nuclear membrane, as occurs during interphase in all eukaryotes. Here we report on the role of the essential nuclear envelope/endoplasmic reticulum (NE/ER) protein Brl1 in regulating the membrane composition of the NE/ER. We show that Brl1 and two other proteins characterized previously-Brr6, which is closely related to Brl1, and Apq12-function together and are required for lipid homeostasis. All three transmembrane proteins are localized to the NE and can be coprecipitated. As has been shown for mutations affecting Brr6 and Apq12, mutations in Brl1 lead to defects in lipid metabolism, increased sensitivity to drugs that inhibit enzymes involved in lipid synthesis, and strong genetic interactions with mutations affecting lipid metabolism. Mutations affecting Brl1 or Brr6 or the absence of Apq12 leads to hyperfluid membranes, because mutant cells are hypersensitive to agents that increase membrane fluidity. We suggest that the defects in nuclear pore complex biogenesis and mRNA export seen in these mutants are consequences of defects in maintaining the biophysical properties of the NE.
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Liu L, Markham K, Blazeck J, Zhou N, Leon D, Otoupal P, Alper HS. Surveying the lipogenesis landscape in Yarrowia lipolytica through understanding the function of a Mga2p regulatory protein mutant. Metab Eng 2015. [DOI: 10.1016/j.ymben.2015.07.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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40
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Ottaviano D, Montanari A, De Angelis L, Santomartino R, Visca A, Brambilla L, Rinaldi T, Bello C, Reverberi M, Bianchi MM. Unsaturated fatty acids-dependent linkage between respiration and fermentation revealed by deletion of hypoxic regulatory KlMGA2 gene in the facultative anaerobe-respiratory yeast Kluyveromyces lactis. FEMS Yeast Res 2015; 15:fov028. [PMID: 26019145 DOI: 10.1093/femsyr/fov028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2015] [Indexed: 01/03/2023] Open
Abstract
In the yeast Kluyveromyces lactis, the inactivation of structural or regulatory glycolytic and fermentative genes generates obligate respiratory mutants which can be characterized by sensitivity to the mitochondrial drug antimycin A on glucose medium (Rag(-) phenotype). Rag(-) mutations can occasionally be generated by the inactivation of genes not evidently related to glycolysis or fermentation. One such gene is the hypoxic regulatory gene KlMGA2. In this work, we report a study of the many defects, in addition to the Rag(-) phenotype, generated by KlMGA2 deletion. We analyzed the fermentative and respiratory metabolism, mitochondrial functioning and morphology in the Klmga2Δ strain. We also examined alterations in the regulation of the expression of lipid biosynthetic genes, in particular fatty acids, ergosterol and cardiolipin, under hypoxic and cold stress and the phenotypic suppression by unsaturated fatty acids of the deleted strain. Results indicate that, despite the fact that the deleted mutant strain had a typical glycolytic/fermentative phenotype and KlMGA2 is a hypoxic regulatory gene, the deletion of this gene generated defects linked to mitochondrial functions suggesting new roles of this protein in the general regulation and cellular fitness of K. lactis. Supplementation of unsaturated fatty acids suppressed or modified these defects suggesting that KlMga2 modulates membrane functioning or membrane-associated functions, both cytoplasmic and mitochondrial.
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Affiliation(s)
- Daniela Ottaviano
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy
| | - Arianna Montanari
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy
| | - Lorenzo De Angelis
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy
| | - Rosa Santomartino
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy
| | - Andrea Visca
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy
| | - Luca Brambilla
- Department of Biotechnology and Biosciences, Bicocca University of Milan, p.zza Della Scienza 2, 20126 Milan, Italy
| | - Teresa Rinaldi
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy Pasteur Institut Cenci-Bolognetti Foundation, p.le Aldo Moro 5, 00185 Rome, Italy
| | - Cristiano Bello
- Departement of Environmental Biology, Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy
| | - Massimo Reverberi
- Departement of Environmental Biology, Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy
| | - Michele M Bianchi
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, p.le Aldo Moro 5, 00185 Rome, Italy
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Naumann S, Meyer JP, Kiesow A, Mrestani Y, Wohlrab J, Neubert RH. Controlled nail delivery of a novel lipophilic antifungal agent using various modern drug carrier systems as well as in vitro and ex vivo model systems. J Control Release 2014; 180:60-70. [DOI: 10.1016/j.jconrel.2014.02.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/11/2014] [Accepted: 02/13/2014] [Indexed: 12/28/2022]
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Koch B, Schmidt C, Daum G. Storage lipids of yeasts: a survey of nonpolar lipid metabolism in Saccharomyces cerevisiae, Pichia pastoris, and Yarrowia lipolytica. FEMS Microbiol Rev 2014; 38:892-915. [PMID: 24597968 DOI: 10.1111/1574-6976.12069] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 02/21/2014] [Accepted: 02/21/2014] [Indexed: 11/29/2022] Open
Abstract
Biosynthesis and storage of nonpolar lipids, such as triacylglycerols (TG) and steryl esters (SE), have gained much interest during the last decades because defects in these processes are related to severe human diseases. The baker's yeast Saccharomyces cerevisiae has become a valuable tool to study eukaryotic lipid metabolism because this single-cell microorganism harbors many enzymes and pathways with counterparts in mammalian cells. In this article, we will review aspects of TG and SE metabolism and turnover in the yeast that have been known for a long time and combine them with new perceptions of nonpolar lipid research. We will provide a detailed insight into the mechanisms of nonpolar lipid synthesis, storage, mobilization, and degradation in the yeast S. cerevisiae. The central role of lipid droplets (LD) in these processes will be addressed with emphasis on the prevailing view that this compartment is more than only a depot for TG and SE. Dynamic and interactive aspects of LD with other organelles will be discussed. Results obtained with S. cerevisiae will be complemented by recent investigations of nonpolar lipid research with Yarrowia lipolytica and Pichia pastoris. Altogether, this review article provides a comprehensive view of nonpolar lipid research in yeast.
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Affiliation(s)
- Barbara Koch
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
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43
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To Sense or Die: Mechanisms of Temperature Sensing in Fungal Pathogens. CURRENT FUNGAL INFECTION REPORTS 2014. [DOI: 10.1007/s12281-014-0182-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Klug L, Daum G. Yeast lipid metabolism at a glance. FEMS Yeast Res 2014; 14:369-88. [DOI: 10.1111/1567-1364.12141] [Citation(s) in RCA: 199] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/23/2014] [Accepted: 02/02/2014] [Indexed: 01/07/2023] Open
Affiliation(s)
- Lisa Klug
- Institute of Biochemistry; Graz University of Technology; Graz Austria
| | - Günther Daum
- Institute of Biochemistry; Graz University of Technology; Graz Austria
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Hoepfner D, Helliwell SB, Sadlish H, Schuierer S, Filipuzzi I, Brachat S, Bhullar B, Plikat U, Abraham Y, Altorfer M, Aust T, Baeriswyl L, Cerino R, Chang L, Estoppey D, Eichenberger J, Frederiksen M, Hartmann N, Hohendahl A, Knapp B, Krastel P, Melin N, Nigsch F, Oakeley EJ, Petitjean V, Petersen F, Riedl R, Schmitt EK, Staedtler F, Studer C, Tallarico JA, Wetzel S, Fishman MC, Porter JA, Movva NR. High-resolution chemical dissection of a model eukaryote reveals targets, pathways and gene functions. Microbiol Res 2014; 169:107-20. [DOI: 10.1016/j.micres.2013.11.004] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 11/25/2013] [Accepted: 11/25/2013] [Indexed: 01/03/2023]
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Montefusco DJ, Matmati N, Hannun YA. The yeast sphingolipid signaling landscape. Chem Phys Lipids 2014; 177:26-40. [PMID: 24220500 PMCID: PMC4211598 DOI: 10.1016/j.chemphyslip.2013.10.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/18/2013] [Accepted: 10/19/2013] [Indexed: 12/13/2022]
Abstract
Sphingolipids are recognized as signaling mediators in a growing number of pathways, and represent potential targets to address many diseases. The study of sphingolipid signaling in yeast has created a number of breakthroughs in the field, and has the potential to lead future advances. The aim of this article is to provide an inclusive view of two major frontiers in yeast sphingolipid signaling. In the first section, several key studies in the field of sphingolipidomics are consolidated to create a yeast sphingolipidome that ranks nearly all known sphingolipid species by their level in a resting yeast cell. The second section presents an overview of most known phenotypes identified for sphingolipid gene mutants, presented with the intention of illuminating not yet discovered connections outside and inside of the field.
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Affiliation(s)
- David J Montefusco
- Dept. Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, United States.
| | - Nabil Matmati
- Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, United States
| | - Yusuf A Hannun
- Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, United States.
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The natural diyne-furan fatty acid EV-086 is an inhibitor of fungal delta-9 fatty acid desaturation with efficacy in a model of skin dermatophytosis. Antimicrob Agents Chemother 2013; 58:455-66. [PMID: 24189258 DOI: 10.1128/aac.01443-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Human fungal infections represent a therapeutic challenge. Although effective strategies for treatment are available, resistance is spreading, and many therapies have unacceptable side effects. A clear need for novel antifungal targets and molecules is thus emerging. Here, we present the identification and characterization of the plant-derived diyne-furan fatty acid EV-086 as a novel antifungal compound. EV-086 has potent and broad-spectrum activity in vitro against Candida, Aspergillus, and Trichophyton spp., whereas activities against bacteria and human cell lines are very low. Chemical-genetic profiling of Saccharomyces cerevisiae deletion mutants identified lipid metabolic processes and organelle organization and biogenesis as targets of EV-086. Pathway modeling suggested that EV-086 inhibits delta-9 fatty acid desaturation, an essential process in S. cerevisiae, depending on the delta-9 fatty acid desaturase OLE1. Delta-9 unsaturated fatty acids-but not saturated fatty acids-antagonized the EV-086-mediated growth inhibition, and transcription of the OLE1 gene was strongly upregulated in the presence of EV-086. EV-086 increased the ratio of saturated to unsaturated free fatty acids and phosphatidylethanolamine fatty acyl chains, respectively. Furthermore, EV-086 was rapidly taken up into the lipid fraction of the cell and incorporated into phospholipids. Together, these findings demonstrate that EV-086 is an inhibitor of delta-9 fatty acid desaturation and that the mechanism of inhibition might involve an EV-086-phospholipid. Finally, EV-086 showed efficacy in a guinea pig skin dermatophytosis model of topical Trichophyton infection, which demonstrates that delta-9 fatty acid desaturation is a valid antifungal target, at least for dermatophytoses.
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Kolawa N, Sweredoski MJ, Graham RLJ, Oania R, Hess S, Deshaies RJ. Perturbations to the ubiquitin conjugate proteome in yeast δubx mutants identify Ubx2 as a regulator of membrane lipid composition. Mol Cell Proteomics 2013; 12:2791-803. [PMID: 23793018 PMCID: PMC3790291 DOI: 10.1074/mcp.m113.030163] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Yeast Cdc48 (p97/VCP in human cells) is a hexameric AAA ATPase that is thought to use ATP hydrolysis to power the segregation of ubiquitin-conjugated proteins from tightly bound partners. Current models posit that Cdc48 is linked to its substrates through adaptor proteins, including a family of seven proteins (13 in human) that contain a Cdc48-binding UBX domain. However, few substrates for specific UBX proteins are known, and hence the generality of this hypothesis remains untested. Here, we use mass spectrometry to identify ubiquitin conjugates that accumulate in cdc48 and ubx mutants. Different ubx mutants exhibit unique patterns of conjugate accumulation that point to functional specialization of individual Ubx proteins. To validate our findings, we examined in detail the endoplasmic reticulum-bound transcription factor Spt23, which we identified as a putative Ubx2 substrate. Mutant ubx2Δ cells are deficient in both cleaving the ubiquitinated 120 kDa precursor of Spt23 to form active p90 and in localizing p90 to the nucleus, resulting in reduced expression of the target gene OLE1, which encodes fatty acid desaturase. Our findings provide a resource for future investigations on Cdc48, illustrate the utility of proteomics to identify ligands for specific ubiquitin receptor pathways, and uncover Ubx2 as a key player in the regulation of membrane lipid biosynthesis.
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Samanfar B, Omidi K, Hooshyar M, Laliberte B, Alamgir M, Seal AJ, Ahmed-Muhsin E, Viteri DF, Said K, Chalabian F, Golshani A, Wainer G, Burnside D, Shostak K, Bugno M, Willmore WG, Smith ML, Golshani A. Large-scale investigation of oxygen response mutants in Saccharomyces cerevisiae. MOLECULAR BIOSYSTEMS 2013; 9:1351-9. [PMID: 23467670 DOI: 10.1039/c3mb25516f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A genome-wide screen of a yeast non-essential gene-deletion library was used to identify sick phenotypes due to oxygen deprivation. The screen provided a manageable list of 384 potentially novel as well as known oxygen responding (anoxia-survival) genes. The gene-deletion mutants were further assayed for sensitivity to ferrozine and cobalt to obtain a subset of 34 oxygen-responsive candidate genes including the known hypoxic gene activator, MGA2. With each mutant in this subset a plasmid based β-galactosidase assay was performed using the anoxic-inducible promoter from OLE1 gene, and 17 gene deletions were identified that inhibit induction under anaerobic conditions. Genetic interaction analysis for one of these mutants, the RNase-encoding POP2 gene, revealed synthetic sick interactions with a number of genes involved in oxygen sensing and response. Knockdown experiments for CNOT8, human homolog of POP2, reduced cell survival under low oxygen condition suggesting a similar function in human cells.
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Affiliation(s)
- Bahram Samanfar
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada
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