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Rosas-Paz M, Zamora-Bello A, Torres-Ramírez N, Villarreal-Huerta D, Romero-Aguilar L, Pardo JP, El Hafidi M, Sandoval G, Segal-Kischinevzky C, González J. Nitrogen limitation-induced adaptive response and lipogenesis in the Antarctic yeast Rhodotorula mucilaginosa M94C9. Front Microbiol 2024; 15:1416155. [PMID: 39161597 PMCID: PMC11330776 DOI: 10.3389/fmicb.2024.1416155] [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] [Received: 04/11/2024] [Accepted: 07/02/2024] [Indexed: 08/21/2024] Open
Abstract
The extremotolerant red yeast Rhodotorula mucilaginosa displays resilience to diverse environmental stressors, including cold, osmolarity, salinity, and oligotrophic conditions. Particularly, this yeast exhibits a remarkable ability to accumulate lipids and carotenoids in response to stress conditions. However, research into lipid biosynthesis has been hampered by limited genetic tools and a scarcity of studies on adaptive responses to nutrient stressors stimulating lipogenesis. This study investigated the impact of nitrogen stress on the adaptive response in Antarctic yeast R. mucilaginosa M94C9. Varied nitrogen availability reveals a nitrogen-dependent modulation of biomass and lipid droplet production, accompanied by significant ultrastructural changes to withstand nitrogen starvation. In silico analysis identifies open reading frames of genes encoding key lipogenesis enzymes, including acetyl-CoA carboxylase (Acc1), fatty acid synthases 1 and 2 (Fas1/Fas2), and acyl-CoA diacylglycerol O-acyltransferase 1 (Dga1). Further investigation into the expression profiles of RmACC1, RmFAS1, RmFAS2, and RmDGA1 genes under nitrogen stress revealed that the prolonged up-regulation of the RmDGA1 gene is a molecular indicator of lipogenesis. Subsequent fatty acid profiling unveiled an accumulation of oleic and palmitic acids under nitrogen limitation during the stationary phase. This investigation enhances our understanding of nitrogen stress adaptation and lipid biosynthesis, offering valuable insights into R. mucilaginosa M94C9 for potential industrial applications in the future.
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Affiliation(s)
- Miguel Rosas-Paz
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Posgrado en Ciencias Biológicas, Unidad de Posgrado, Circuito de Posgrados, Ciudad Universitaria, Mexico City, Mexico
| | - Alberto Zamora-Bello
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Posgrado en Ciencias Bioquímicas, Unidad de Posgrado, Ciudad Universitaria, Mexico City, Mexico
| | - Nayeli Torres-Ramírez
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Diana Villarreal-Huerta
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Posgrado en Ciencias Biológicas, Unidad de Posgrado, Circuito de Posgrados, Ciudad Universitaria, Mexico City, Mexico
| | - Lucero Romero-Aguilar
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Juan Pablo Pardo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Mohammed El Hafidi
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Georgina Sandoval
- Laboratorio de Innovación en Bioenergéticos y Bioprocesos Avanzados, Unidad de Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco A. C., Guadalajara, Mexico
| | - Claudia Segal-Kischinevzky
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - James González
- Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
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2
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Carmon T, Hill N, Sripathi VR, Gossett ZB, Fakas S. The PAH1-encoded phosphatidate phosphatase of Yarrowia lipolytica differentially affects gene expression and lipid biosynthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159544. [PMID: 39089641 DOI: 10.1016/j.bbalip.2024.159544] [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: 04/30/2024] [Revised: 07/25/2024] [Accepted: 07/29/2024] [Indexed: 08/04/2024]
Abstract
Yarrowia lipolytica is a model oleaginous yeast with a strong capacity for lipid accumulation, yet its lipid metabolic pathways and regulatory mechanisms remain largely unexplored. The PAH1-encoded phosphatidate (PA) phosphatase governs lipid biosynthesis by its enzymatic activity and regulating the transcription of genes involved in phospholipid biosynthesis. In this work, we examined the effect of the loss of Pah1 (i.e., pah1Δ) on cell metabolism in cells growing in low- and high-glucose media. Multi-omics analyses revealed the global effect of the pah1Δ mutation on lipid and central carbon metabolism. Lipidomics analyses showed that the pah1Δ mutation caused a massive decrease in the masses of triacylglycerol (TAG) and diacylglycerol (DAG), and these effects were independent of glucose concentration in the media. Conversely, phospholipid levels declined in low-glucose media but increased in high-glucose media. The loss of Pah1 affected the expression of genes involved in key pathways of glucose metabolism, such as glycolysis, citric acid cycle, oxidative phosphorylation, and the pentose phosphate pathway, and these effects were more pronounced in high-glucose media. In lipid biosynthesis, the genes catalyzing phosphatidylcholine (PC) synthesis from phosphatidylethanolamine (PE) were upregulated within the CDP-DAG pathway. In contrast, PC synthesis through the Kennedy pathway was downregulated. The ethanolamine branch of the Kennedy pathway that synthesizes PE was also upregulated in pah1Δ. Interestingly, we noted a massive increase in the levels of lysophospholipids, consistent with the upregulation of genes involved in lipid turnover. Overall, this work identified novel regulatory roles of Pah1 in lipid biosynthesis and gene expression.
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Affiliation(s)
- Taylor Carmon
- Department of Food and Animal Sciences, Alabama A&M University, Normal, AL 35762, USA
| | - Na'Taja Hill
- Department of Food and Animal Sciences, Alabama A&M University, Normal, AL 35762, USA
| | | | - Zachary B Gossett
- Department of Food and Animal Sciences, Alabama A&M University, Normal, AL 35762, USA
| | - Stylianos Fakas
- Department of Food and Animal Sciences, Alabama A&M University, Normal, AL 35762, USA.
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3
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Sah SK, Fan J, Blanford J, Shanklin J, Xu C. Physiological Functions of Phospholipid:Diacylglycerol Acyltransferases. PLANT & CELL PHYSIOLOGY 2024; 65:863-871. [PMID: 37702708 DOI: 10.1093/pcp/pcad106] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/01/2023] [Accepted: 09/08/2023] [Indexed: 09/14/2023]
Abstract
Triacylglycerol (TAG) is among the most energy dense storage forms of reduced carbon in living systems. TAG metabolism plays critical roles in cellular energy balance, lipid homeostasis, cell growth and stress responses. In higher plants, microalgae and fungi, TAG is assembled by acyl-CoA-dependent and acyl-CoA-independent pathways catalyzed by diacylglycerol (DAG) acyltransferase and phospholipid:DAG acyltransferase (PDAT), respectively. This review contains a summary of the current understanding of the physiological functions of PDATs. Emphasis is placed on their role in lipid remodeling and lipid homeostasis in response to abiotic stress or perturbations in lipid metabolism.
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Affiliation(s)
- Saroj Kumar Sah
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jantana Blanford
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | | | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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4
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Barbosa AD, Siniossoglou S. Membranes that make fat: roles of membrane lipids as acyl donors for triglyceride synthesis and organelle function. FEBS Lett 2024; 598:1226-1234. [PMID: 38140812 DOI: 10.1002/1873-3468.14793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/05/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023]
Abstract
Triglycerides constitute an inert storage form for fatty acids deposited in lipid droplets and are mobilized to provide metabolic energy or membrane building blocks. The biosynthesis of triglycerides is highly conserved within eukaryotes and normally involves the sequential esterification of activated fatty acids with a glycerol backbone. Some eukaryotes, however, can also use cellular membrane lipids as direct fatty acid donors for triglyceride synthesis. The biological significance of a pathway that generates triglycerides at the expense of organelle membranes has remained elusive. Here we review current knowledge on how cells use membrane lipids as fatty acid donors for triglyceride synthesis and discuss the hypothesis that a primary function of this pathway is to regulate membrane lipid remodeling and organelle function.
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Affiliation(s)
- Antonio D Barbosa
- Cambridge Institute for Medical Research, University of Cambridge, UK
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5
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Dong G, Zhao Y, Ding W, Xu S, Zhang Q, Zhao H, Shi S. Metabolic engineering of Saccharomyces cerevisiae for de novo production of odd-numbered medium-chain fatty acids. Metab Eng 2024; 82:100-109. [PMID: 38325640 DOI: 10.1016/j.ymben.2024.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 12/18/2023] [Accepted: 01/26/2024] [Indexed: 02/09/2024]
Abstract
Odd-numbered fatty acids (FAs) have been widely used in nutrition, agriculture, and chemical industries. Recently, some studies showed that they could be produced from bacteria or yeast, but the products are almost exclusively odd-numbered long-chain FAs. Here we report the design and construction of two biosynthetic pathways in Saccharomyces cerevisiae for de novo production of odd-numbered medium-chain fatty acids (OMFAs) via ricinoleic acid and 10-hydroxystearic acid, respectively. The production of OMFAs was enabled by introducing a hydroxy fatty acid cleavage pathway, including an alcohol dehydrogenase from Micrococcus luteus, a Baeyer-Villiger monooxygenase from Pseudomonas putida, and a lipase from Pseudomonas fluorescens. These OMFA biosynthetic pathways were optimized by eliminating the rate-limiting step, generating heptanoic acid, 11-hydroxyundec-9-enoic acid, nonanoic acid, and 9-hydroxynonanoic acid at 7.83 mg/L, 9.68 mg/L, 9.43 mg/L and 13.48 mg/L, respectively. This work demonstrates the biological production of OMFAs in a sustainable manner in S. cerevisiae.
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Affiliation(s)
- Genlai Dong
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China; Key Laboratory of Natural Products, Henan Academy of Sciences, Zhengzhou, 450002, China
| | - Ying Zhao
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Wentao Ding
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Shijie Xu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Qi Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
| | - Shuobo Shi
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China.
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6
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Deng Y, Zhu H, Wang Y, Dong Y, Du J, Yu Q, Li M. The Endoplasmic Reticulum-Plasma Membrane Tethering Protein Ice2 Controls Lipid Droplet Size via the Regulation of Phosphatidylcholine in Candida albicans. J Fungi (Basel) 2024; 10:87. [PMID: 38276033 PMCID: PMC10817647 DOI: 10.3390/jof10010087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/13/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
Lipid droplets (LDs) are intracellular organelles that play important roles in cellular lipid metabolism; they change their sizes and numbers in response to both intracellular and extracellular signals. Changes in LD size reflect lipid synthesis and degradation and affect many cellular activities, including energy supply and membrane synthesis. Here, we focused on the function of the endoplasmic reticulum-plasma membrane tethering protein Ice2 in LD dynamics in the fungal pathogen Candida albicans (C. albicans). Nile red staining and size quantification showed that the LD size increased in the ice2Δ/Δ mutant, indicating the critical role of Ice2 in the regulation of LD dynamics. A lipid content analysis further demonstrated that the mutant had lower phosphatidylcholine levels. As revealed with GFP labeling and fluorescence microscopy, the methyltransferase Cho2, which is involved in phosphatidylcholine synthesis, had poorer localization in the plasma membrane in the mutant than in the wild-type strain. Interestingly, the addition of the phosphatidylcholine precursor choline led to the recovery of normal-sized LDs in the mutant. These results indicated that Ice2 regulates LD size by controlling intracellular phosphatidylcholine levels and that endoplasmic reticulum-plasma membrane tethering proteins play a role in lipid metabolism regulation in C. albicans. This study provides significant findings for further investigation of the lipid metabolism in fungi.
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Affiliation(s)
| | | | | | | | | | | | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.D.); (H.Z.); (Y.W.); (Y.D.); (J.D.)
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7
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Zhang H, Wang Z, Sun C, Zhang C, Liu H, Cui Q, Song X, Wang S. A phospholipid:diacylglycerol acyltransferase is involved in the regulation of phospholipids homeostasis in oleaginous Aurantiochytrium sp. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:142. [PMID: 37752571 PMCID: PMC10523756 DOI: 10.1186/s13068-023-02396-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/18/2023] [Indexed: 09/28/2023]
Abstract
BACKGROUND Thraustochytrids have gained attention as a potential source for the production of docosahexaenoic acid (DHA), where DHA is predominantly stored in the form of triacylglycerol (TAG). The TAG biosynthesis pathways, including the acyl-CoA-dependent Kennedy pathway and the acyl-CoA-independent pathway, have been predicted in thraustochytrids, while the specific details regarding their roles are currently uncertain. RESULTS Phospholipid:diacylglycerol acyltransferase (PDAT) plays a key role in the acyl-CoA-independent pathway by transferring acyl-group from phospholipids (PL) to diacylglycerol (DAG) to from TAG. In thraustochytrid Aurantiochytrium sp. SD116, an active AuPDAT was confirmed by heterologous expression in a TAG-deficient yeast strain H1246. Analysis of AuPDAT function in vivo revealed that deletion of AuPDAT led to slow growth and a significant decrease in cell number, but improved PL content in the single cell during the cell growth and lipid accumulation phases. Interestingly, deletion of AuPDAT did not affect total lipid and TAG content, but both were significantly increased within a single cell. Moreover, overexpression of AuPDAT also resulted in a decrease in cell number, while the total lipid and cell diameter of a single cell were markedly increased. Altogether, both up-regulation and down-regulation of AuPDAT expression affected the cell number, which further associated with the total lipid and TAG content in a single cell. CONCLUSIONS Our study demonstrates that AuPDAT-mediated pathway play a minor role in TAG synthesis, and that the function of AuPDAT may be involved in regulating PL homeostasis by converting PL to TAG in a controlled manner. These findings expand our understanding of lipid biosynthesis in Aurantiochytrium sp. and open new avenues for developing "customized cell factory" for lipid production.
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Affiliation(s)
- Huidan Zhang
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No.189 Songling Road, Laoshan District, Qingdao, 266101, Shandong, China
- Shandong Provincial Key Laboratory of Energy Genetics, Shandong Engineering Laboratory of Single Cell Oil, Shandong Energy Institute, Qingdao, 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China
| | - Zhuojun Wang
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No.189 Songling Road, Laoshan District, Qingdao, 266101, Shandong, China
- Shandong Provincial Key Laboratory of Energy Genetics, Shandong Engineering Laboratory of Single Cell Oil, Shandong Energy Institute, Qingdao, 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China
| | - Caili Sun
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No.189 Songling Road, Laoshan District, Qingdao, 266101, Shandong, China
- Shandong Provincial Key Laboratory of Energy Genetics, Shandong Engineering Laboratory of Single Cell Oil, Shandong Energy Institute, Qingdao, 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China
| | - Chuchu Zhang
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, China
| | - Huan Liu
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No.189 Songling Road, Laoshan District, Qingdao, 266101, Shandong, China
- Shandong Provincial Key Laboratory of Energy Genetics, Shandong Engineering Laboratory of Single Cell Oil, Shandong Energy Institute, Qingdao, 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No.189 Songling Road, Laoshan District, Qingdao, 266101, Shandong, China
- Shandong Provincial Key Laboratory of Energy Genetics, Shandong Engineering Laboratory of Single Cell Oil, Shandong Energy Institute, Qingdao, 266101, Shandong, China
- Qingdao New Energy Shandong Laboratory, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China
| | - Xiaojin Song
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No.189 Songling Road, Laoshan District, Qingdao, 266101, Shandong, China.
- Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, 810016, Qinghai, China.
- Shandong Provincial Key Laboratory of Energy Genetics, Shandong Engineering Laboratory of Single Cell Oil, Shandong Energy Institute, Qingdao, 266101, Shandong, China.
- Qingdao New Energy Shandong Laboratory, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China.
| | - Sen Wang
- CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No.189 Songling Road, Laoshan District, Qingdao, 266101, Shandong, China.
- Shandong Provincial Key Laboratory of Energy Genetics, Shandong Engineering Laboratory of Single Cell Oil, Shandong Energy Institute, Qingdao, 266101, Shandong, China.
- Qingdao New Energy Shandong Laboratory, Qingdao Engineering Laboratory of Single Cell Oil, Qingdao, 266101, Shandong, China.
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8
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Klińska-Bąchor S, Kędzierska S, Demski K, Banaś A. Phospholipid:diacylglycerol acyltransferase1-overexpression stimulates lipid turnover, oil production and fitness in cold-grown plants. BMC PLANT BIOLOGY 2023; 23:370. [PMID: 37491206 PMCID: PMC10369929 DOI: 10.1186/s12870-023-04379-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 07/12/2023] [Indexed: 07/27/2023]
Abstract
BACKGROUND Extensive population growth and climate change accelerate the search for alternative ways of plant-based biomass, biofuel and feed production. Here, we focus on hitherto unknow, new promising cold-stimulated function of phospholipid:diacylglycerol acyltransferase1 (PDAT1) - an enzyme catalyzing the last step of triacylglycerol (TAG) biosynthesis. RESULT Overexpression of AtPDAT1 boosted seed yield by 160% in Arabidopsis plants exposed to long-term cold compared to standard conditions. Such seeds increased both their weight and acyl-lipids content. This work also elucidates PDAT1's role in leaves, which was previously unclear. Aerial parts of AtPDAT1-overexpressing plants were characterized by accelerated growth at early and vegetative stages of development and by biomass weighing three times more than control. Overexpression of PDAT1 increased the expression of SUGAR-DEPENDENT1 (SDP1) TAG lipase and enhanced lipid remodeling, driving lipid turnover and influencing biomass increment. This effect was especially pronounced in cold conditions, where the elevated synergistic expression of PDAT1 and SDP1 resulted in double biomass increase compared to standard conditions. Elevated phospholipid remodeling also enhanced autophagy flux in AtPDAT1-overexpresing lines subjected to cold, despite the overall diminished autophagy intensity in cold conditions. CONCLUSIONS Our data suggest that PDAT1 promotes greater vitality in cold-exposed plants, stimulates their longevity and boosts oilseed oil production at low temperature.
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Affiliation(s)
- Sylwia Klińska-Bąchor
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk, 80-307, Poland.
| | - Sara Kędzierska
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk, 80-307, Poland
| | - Kamil Demski
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Lomma, Box 190, 234 22, Sweden
| | - Antoni Banaś
- Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk, 80-307, Poland
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9
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Greenwood BL, Luo Z, Ahmed T, Huang D, Stuart DT. Saccharomyces cerevisiae Δ9-desaturase Ole1 forms a supercomplex with Slc1 and Dga1. J Biol Chem 2023:104882. [PMID: 37269945 PMCID: PMC10302205 DOI: 10.1016/j.jbc.2023.104882] [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: 12/04/2022] [Revised: 05/04/2023] [Accepted: 05/07/2023] [Indexed: 06/05/2023] Open
Abstract
Biosynthesis of the various lipid species that compose cellular membranes and lipid droplets depends on the activity of multiple enzymes functioning in coordinated pathways. The flux of intermediates through lipid biosynthetic pathways is regulated to respond to nutritional and environmental demands placed on the cell necessitating that there be extensive flexibility in pathway activity and organization. This flexibility can in part be achieved through the organization of biosynthetic enzymes into metabolon supercomplexes. However, the composition and organization of such supercomplexes remains unclear. Here, we identified protein-protein interactions between acyltransferases Sct1, Gpt2, Slc1, Dga1 and the Δ9 acyl-CoA desaturase Ole1 in Saccharomyces cerevisiae. We further determined that a subset of these acyltransferases interact with each other without Ole1 acting as a scaffold. We show that truncated versions of Dga1 lacking the carboxyl-terminal 20 amino acid residues are non-functional and unable to bind Ole1. Furthermore, charged-to-alanine scanning mutagenesis revealed that a cluster of charged residues near the carboxyl-terminus were required for the interaction with Ole1. Mutation of these charged residues disrupted the interaction between Dga1 and Ole1, but allowed Dga1 to retain catalytic activity and to induce lipid droplet formation. These data support the formation of a complex of acyltransferases involved in lipid biosynthesis that interacts with Ole1, the sole acyl-CoA desaturase in S. cerevisiae, that can channel unsaturated acyl-chains toward phospholipid or triacylglycerol synthesis. This desaturasome complex may provide the architecture that allows for the necessary flux of de novo synthesized unsaturated acyl-CoA to phospholipid or triacylglycerol synthesis as demanded by cellular requirements.
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Affiliation(s)
- Brianna L Greenwood
- Department of Biochemistry, 561 Medical Sciences Building, University of Alberta, Edmonton AB, T6G 2R3, Canada
| | - Zijun Luo
- Department of Biochemistry, 561 Medical Sciences Building, University of Alberta, Edmonton AB, T6G 2R3, Canada
| | - Tareq Ahmed
- Department of Biochemistry, 561 Medical Sciences Building, University of Alberta, Edmonton AB, T6G 2R3, Canada
| | - Daniel Huang
- Department of Biochemistry, 561 Medical Sciences Building, University of Alberta, Edmonton AB, T6G 2R3, Canada
| | - David T Stuart
- Department of Biochemistry, 561 Medical Sciences Building, University of Alberta, Edmonton AB, T6G 2R3, Canada.
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10
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Zadoorian A, Du X, Yang H. Lipid droplet biogenesis and functions in health and disease. Nat Rev Endocrinol 2023:10.1038/s41574-023-00845-0. [PMID: 37221402 DOI: 10.1038/s41574-023-00845-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 79.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/25/2023] [Indexed: 05/25/2023]
Abstract
Ubiquitous yet unique, lipid droplets are intracellular organelles that are increasingly being recognized for their versatility beyond energy storage. Advances uncovering the intricacies of their biogenesis and the diversity of their physiological and pathological roles have yielded new insights into lipid droplet biology. Despite these insights, the mechanisms governing the biogenesis and functions of lipid droplets remain incompletely understood. Moreover, the causal relationship between the biogenesis and function of lipid droplets and human diseases is poorly resolved. Here, we provide an update on the current understanding of the biogenesis and functions of lipid droplets in health and disease, highlighting a key role for lipid droplet biogenesis in alleviating cellular stresses. We also discuss therapeutic strategies of targeting lipid droplet biogenesis, growth or degradation that could be applied in the future to common diseases, such as cancer, hepatic steatosis and viral infection.
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Affiliation(s)
- Armella Zadoorian
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Ximing Du
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia.
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11
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Farese RV, Walther TC. Glycerolipid Synthesis and Lipid Droplet Formation in the Endoplasmic Reticulum. Cold Spring Harb Perspect Biol 2023; 15:a041246. [PMID: 36096640 PMCID: PMC10153804 DOI: 10.1101/cshperspect.a041246] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
More than 60 years ago, Eugene Kennedy and coworkers elucidated the endoplasmic reticulum (ER)-based pathways of glycerolipid synthesis, including the synthesis of phospholipids and triacylglycerols (TGs). The reactions of the Kennedy pathway were identified by studying the conversion of lipid intermediates and the isolation of biochemical enzymatic activities, but the molecular basis for most of these reactions was unknown. With recent progress in the cell biology, biochemistry, and structural biology in this area, we have a much more mechanistic understanding of this pathway and its reactions. In this review, we provide an overview of molecular aspects of glycerolipid synthesis, focusing on recent insights into the synthesis of TGs. Further, we go beyond the Kennedy pathway to describe the mechanisms for storage of TG in cytosolic lipid droplets and discuss how overwhelming these pathways leads to ER stress and cellular toxicity, as seen in diseases linked to lipid overload and obesity.
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Affiliation(s)
- Robert V Farese
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115, USA
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
- Center for Causes and Prevention of Cardiovascular Disease (CAP-CVD), Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115, USA
| | - Tobias C Walther
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115, USA
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02142, USA
- Center for Causes and Prevention of Cardiovascular Disease (CAP-CVD), Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115, USA
- Howard Hughes Medical Institute Boston, Boston, Massachusetts 02115, USA
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12
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Mierke F, Brink DP, Norbeck J, Siewers V, Andlid T. Functional genome annotation and transcriptome analysis of Pseudozyma hubeiensis BOT-O, an oleaginous yeast that utilizes glucose and xylose at equal rates. Fungal Genet Biol 2023; 166:103783. [PMID: 36870442 DOI: 10.1016/j.fgb.2023.103783] [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: 05/06/2022] [Revised: 02/10/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023]
Abstract
Pseudozyma hubeiensis is a basidiomycete yeast that has the highly desirable traits for lignocellulose valorisation of being equally efficient at utilization of glucose and xylose, and capable of their co-utilization. The species has previously mainly been studied for its capacity to produce secreted biosurfactants in the form of mannosylerythritol lipids, but it is also an oleaginous species capable of accumulating high levels of triacylglycerol storage lipids during nutrient starvation. In this study, we aimed to further characterize the oleaginous nature of P. hubeiensis by evaluating metabolism and gene expression responses during storage lipid formation conditions with glucose or xylose as a carbon source. The genome of the recently isolated P. hubeiensis BOT-O strain was sequenced using MinION long-read sequencing and resulted in the most contiguous P. hubeiensis assembly to date with 18.95 Mb in 31 contigs. Using transcriptome data as experimental support, we generated the first mRNA-supported P. hubeiensis genome annotation and identified 6540 genes. 80% of the predicted genes were assigned functional annotations based on protein homology to other yeasts. Based on the annotation, key metabolic pathways in BOT-O were reconstructed, including pathways for storage lipids, mannosylerythritol lipids and xylose assimilation. BOT-O was confirmed to consume glucose and xylose at equal rates, but during mixed glucose-xylose cultivation glucose was found to be taken up faster. Differential expression analysis revealed that only a total of 122 genes were significantly differentially expressed at a cut-off of |log2 fold change| ≥ 2 when comparing cultivation on xylose with glucose, during exponential growth and during nitrogen-starvation. Of these 122 genes, a core-set of 24 genes was identified that were differentially expressed at all time points. Nitrogen-starvation resulted in a larger transcriptional effect, with a total of 1179 genes with significant expression changes at the designated fold change cut-off compared with exponential growth on either glucose or xylose.
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Affiliation(s)
- Friederike Mierke
- Food and Nutrition Science, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden; Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Daniel P Brink
- Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden; Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden
| | - Joakim Norbeck
- Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Verena Siewers
- Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden.
| | - Thomas Andlid
- Food and Nutrition Science, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
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13
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Behera J, Rahman MM, Shockey J, Kilaru A. Acyl-CoA-dependent and acyl-CoA-independent avocado acyltransferases positively influence oleic acid content in nonseed triacylglycerols. FRONTIERS IN PLANT SCIENCE 2023; 13:1056582. [PMID: 36714784 PMCID: PMC9874167 DOI: 10.3389/fpls.2022.1056582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/15/2022] [Indexed: 06/18/2023]
Abstract
In higher plants, acyl-CoA:diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT) catalyze the terminal step of triacylglycerol (TAG) synthesis in acyl-CoA-dependent and -independent pathways, respectively. Avocado (Persea americana) mesocarp, a nonseed tissue, accumulates significant amounts of TAG (~70% by dry weight) that is rich in heart-healthy oleic acid (18:1). The oil accumulation stages of avocado mesocarp development coincide with high expression levels for type-1 DGAT (DGAT1) and PDAT1, although type-2 DGAT (DGAT2) expression remains low. The strong preference for oleic acid demonstrated by the avocado mesocarp TAG biosynthetic machinery represents lucrative biotechnological opportunities, yet functional characterization of these three acyltransferases has not been explored to date. We expressed avocado PaDGAT1, PaDGAT2, and PaPDAT1 in bakers' yeast and leaves of Nicotiana benthamiana. PaDGAT1 complemented the TAG biosynthesis deficiency in the quadruple mutant yeast strain H1246, and substantially elevated total cellular lipid content. In vitro enzyme assays showed that PaDGAT1 prefers oleic acid compared to palmitic acid (16:0). Both PaDGAT1 and PaPDAT1 increased the lipid content and elevated oleic acid levels when expressed independently or together, transiently in N. benthamiana leaves. These results indicate that PaDGAT1 and PaPDAT1 prefer oleate-containing substrates, and their coordinated expression likely contributes to sustained TAG synthesis that is enriched in oleic acid. This study establishes a knowledge base for future metabolic engineering studies focused on exploitation of the biochemical properties of PaDGAT1 and PaPDAT1.
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Affiliation(s)
- Jyoti Behera
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
| | - Md Mahbubur Rahman
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
- dNTP Laboratory, Teaneck, NJ, United States
| | - Jay Shockey
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, Commodity Utilization Research Unit, New Orleans, LA, United States
| | - Aruna Kilaru
- Department of Biological Sciences, East Tennessee State University, Johnson City, TN, United States
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14
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Feng H, Meng P, Zhang S, Chen W, Wang H, Wang C. Insights from comparative transcriptome analysis in the responses of Pb-tolerant fungi Curvularia tsudae to Pb stress. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 249:114476. [PMID: 38321691 DOI: 10.1016/j.ecoenv.2022.114476] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 12/06/2022] [Accepted: 12/23/2022] [Indexed: 02/08/2024]
Abstract
The fungus Curvularia tsudae can survive in environments that are extremely contaminated by heavy metals; however, the underlying molecular mechanisms of heavy metal tolerance are not clear. In this study, we determined the effects of lead (Pb) stress on the growth of C. tsudae and used RNA-Seq to identify significant genes and biological processes involved. The present study showed that C. tsudae had an outstanding resistant capacity to Pb stress and could survive at a concentration of 1600 mg L-1 Pb. Although an obvious inhibition on the growth was observed, the fungus exhibited tolerance as it continued to grow at a Pb concentration of 1600 mg L-1 for seven days. A total of 9997 (9020 up and 977 down) differentially expressed genes (DEGs) were detected in the mycelium of C. tsudae at Pb free (0 mg L-1) and Pb stressed samples. Pathway enrichment analysis identified several biological processes for managing Pb stress. Genes involved in carbohydrate metabolism tended to be modulated in response to Pb stress, while amino acids and the lipid metabolism would also be induced by Pb stress, and up-regulated genes involved in antioxidant substances and ABC transporters may be committed to high Pb tolerance. Our study contributes to the current literature on C. tsudae response to Pb stress and provides a useful reference for fungi as bioremediators in heavy metal-contaminated environments.
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Affiliation(s)
- Huan Feng
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Panpan Meng
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Shouxia Zhang
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Wei Chen
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Haihua Wang
- North Florida Research and Education Center, University of Florida, 155 Research Road, Quincy, FL 32351, USA
| | - Chunyan Wang
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China.
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15
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Zhang Y, Zhang S, Chu Y, Zhang Q, Zhou R, Yu D, Wang S, Lyu L, Xu G, Zhao ZK. Genetic manipulation of the interconversion between diacylglycerols and triacylglycerols in Rhodosporidium toruloides. Front Bioeng Biotechnol 2022; 10:1034972. [PMID: 36394004 PMCID: PMC9643831 DOI: 10.3389/fbioe.2022.1034972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/13/2022] [Indexed: 11/29/2022] Open
Abstract
The basidiomycetous yeast Rhodosporidium toruloides (R. toruloides) is an excellent producer for neutral lipids, including triacylglycerols (TAG). Partially because genetic tools for this yeast were less developed, limited efforts were shown to explore its capacity for the production of higher-value lipids such as diacylglycerols (DAG). Here, four genes linked to the interconversion between DAG and TAG were manipulated to promote the production of DAG and free fatty acids (FFA). Among them, three TAG synthesis-related genes, DGA1, LRO1, and ARE1, were down-regulated successively via the RNA interference technology, and an endogenous TAG lipase encoded by TGL5 was fused with LDP1 and over-expressed to convert TAG into DAG and FFA. Results showed that those engineered R. toruloides strains grew normally under nutrient-rich conditions but notably slower than the parental strain NP11 in the lipid production stage. When cultivated in nitrogen-limited media, engineered strains were able to produce total lipids with improved contents of DAG and FFA by up to two-fold and three-fold, respectively. Further correlation analysis between lipid composition and cell density indicated that the formation of TAG correlated positively with cell growth; however, other lipids including DAG did negatively. This study offered valuable information and strains to engineer R. toruloides for advanced production of fatty acid derivatives.
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Affiliation(s)
- Yue Zhang
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Sufang Zhang
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
| | - Yadong Chu
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
| | - Qi Zhang
- University of Chinese Academy of Sciences, Beijing, China
| | - Renhui Zhou
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
| | - Di Yu
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
| | - Shuang Wang
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Liting Lyu
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
- Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Guowang Xu
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
| | - Zongbao Kent Zhao
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, China
- Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
- *Correspondence: Zongbao Kent Zhao,
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16
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Wang W, Wen H, Jin Q, Yu W, Li G, Wu M, Bai H, Shen L, Wu C. Comparative transcriptome analysis on candidate genes involved in lipid biosynthesis of developing kernels for three walnut cultivars in Xinjiang. FOOD SCIENCE AND HUMAN WELLNESS 2022. [DOI: 10.1016/j.fshw.2022.04.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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17
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Zhang G, Zhang C, Wang Z, Wang Q, Nielsen J, Dai Z. Dual β-oxidation pathway and transcription factor engineering for methyl ketones production in Saccharomyces cerevisiae. Metab Eng 2022; 73:225-234. [PMID: 35987431 DOI: 10.1016/j.ymben.2022.08.004] [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: 05/14/2022] [Revised: 08/05/2022] [Accepted: 08/05/2022] [Indexed: 10/15/2022]
Abstract
Methyl ketones (MK) are highly valuable fatty acid derivatives with broad applications. Microbes based biosynthesis represents an alternative route for production of these usually fossil based chemicals. In this study, we reported metabolic engineering of Saccharomyces cerevisiae to produce MK, including 2-nonanone, 2-undecanone, 2-tridecanone and 2-pentadecanone. Besides enhancing inherent peroxisomal fatty acids β-oxidation cycle, a novel heterologous cytosolic fatty acids β-oxidation pathway was constructed, and this resulted in an increased production of MK by 2-fold. To increase carbon fluxes to methyl ketones, the supply of precursors was enhanced by engineering lipid metabolism, including improving the intracellular biosynthesis of acyl-CoAs, weakening the consumption of acyl-CoAs for lipids storage, and reinforcing activation of free fatty acids to acyl-CoAs. Hereby the titer of MK was improved by 7-fold, reaching 143.72 mg/L. Finally, transcription factor engineering was employed to increase the biosynthesis of methyl ketones and it was found that overexpression of ADR1 can mimic the oleate activated biogenesis and proliferation of peroxisomes, which resulted in a further increased production of MK by 28%. With these modifications and optimization, up to 845 mg/L total MK were produced from glucose in fed-batch fermentation, which is the highest titer of methyl ketones reported produced by fungi.
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Affiliation(s)
- Ge Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Chao Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zheng Wang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Qinhong Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Jens Nielsen
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China; Department of Biology and Biological Engineering, Chalmers University of Technology, SE 412 96, Gothenburg, Sweden.
| | - Zongjie Dai
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China; National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
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18
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An increase in the membrane lipids recycling by PDAT overexpression stimulates the accumulation of triacylglycerol in Nannochloropsis gaditana. J Biotechnol 2022; 357:28-37. [PMID: 35931238 DOI: 10.1016/j.jbiotec.2022.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/18/2022] [Accepted: 07/30/2022] [Indexed: 11/23/2022]
Abstract
Oleaginous microalgae represent potential feedstocks for the sustainable production of lipids thanks to their ability to accumulate triacylglycerols (TAGs). TAG accumulation in several algal species is strongly induced under specific conditions such as nutrient deprivation and high light which, however, also negatively impact growth. Genetic modification of lipogenic pathways can potentially enhance TAG accumulation without negatively affecting growth, avoiding the trade-off between biomass and lipids productivity. In this study, the phospholipid: diacylglycerol acyltransferase (PDAT), an enzyme involved in membrane lipid recycling, was overexpressed in the seawater alga Nannochloropsis gaditana. PDAT overexpression induced increased TAG content in actively growing algae cultures while no effects were observed in conditions naturally stimulating strong lipid accumulation such as high light and nitrogen starvation. The increase of TAG content was confirmed also in a strain cultivated in industrially relevant conditions even though PDAT overexpression, if too strong, the gene overexpression becomes detrimental for growth in the longer term. Results overall suggest that genetic modulation of the PDAT gene represents a promising strategy to increase microalgae lipids content by minimizing negative effects on biomass productivity.
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19
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Lee Y, Park R, Miller SM, Li Y. Genetic compensation of triacylglycerol biosynthesis in the green microalga Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:1069-1080. [PMID: 35727866 PMCID: PMC9545326 DOI: 10.1111/tpj.15874] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 06/10/2022] [Accepted: 06/16/2022] [Indexed: 06/14/2023]
Abstract
Genetic compensation has been proposed to explain phenotypic differences between gene knockouts and knockdowns in several metazoan and plant model systems. With the rapid development of reverse genetic tools such as CRISPR/Cas9 and RNAi in microalgae, it is increasingly important to assess whether genetic compensation affects the phenotype of engineered algal mutants. While exploring triacylglycerol (TAG) biosynthesis pathways in the model alga Chlamydomonas reinhardtii, it was discovered that knockout of certain genes catalyzing rate-limiting steps of TAG biosynthesis, type-2 diacylglycerol acyltransferase genes (DGTTs), triggered genetic compensation under abiotic stress conditions. Genetic compensation of a DGTT1 null mutation by a related PDAT gene was observed regardless of the strain background or mutagenesis approach, for example, CRISPR/Cas 9 or insertional mutagenesis. However, no compensation was found in the PDAT knockout mutant. The effect of PDAT knockout was evaluated in a Δvtc1 mutant, in which PDAT was upregulated under stress, resulting in a 90% increase in TAG content. Knockout of PDAT in the Δvtc1 background induced a 12.8-fold upregulation of DGTT1 and a 272.3% increase in TAG content in Δvtc1/pdat1 cells, while remaining viable. These data suggest that genetic compensation contributes to the genetic robustness of microalgal TAG biosynthetic pathways, maintaining lipid and redox homeostasis in the knockout mutants under abiotic stress. This work demonstrates examples of genetic compensation in microalgae, implies the physiological relevance of genetic compensation in TAG biosynthesis under stress, and provides guidance for future genetic engineering and mutant characterization efforts.
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Affiliation(s)
- Yi‐Ying Lee
- Institute of Marine and Environmental TechnologyUniversity of Maryland Center for Environmental ScienceBaltimoreMD21202USA
| | - Rudolph Park
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMD21250USA
| | - Stephen M. Miller
- Department of Biological SciencesUniversity of Maryland, Baltimore CountyBaltimoreMD21250USA
| | - Yantao Li
- Institute of Marine and Environmental TechnologyUniversity of Maryland Center for Environmental ScienceBaltimoreMD21202USA
- Department of Marine BiotechnologyUniversity of Maryland, Baltimore CountyBaltimoreMD21202USA
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20
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Li M, Zhou P, Chen M, Yu H, Ye L. Spatiotemporal Regulation of Astaxanthin Synthesis in S. cerevisiae. ACS Synth Biol 2022; 11:2636-2649. [PMID: 35914247 DOI: 10.1021/acssynbio.2c00044] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As a high-valued antioxidant, astaxanthin biosynthesis using microbial cell factories has attracted increasing attention. However, its lipophilic nature conflicts with the limited storage capacity for lipophilic substances of model microorganisms such as Saccharomyces cerevisiae. Expansion of lipid droplets by enhancing lipid synthesis provides more storage room while diverting the metabolic flux from the target pathway. Therefore, proper spatial regulation is required. In this study, a library of genes related to lipid metabolism were screened using the trifunctional CRISPR system, identifying opi3 and hrd1 as new engineering targets to promote astaxanthin synthesis by moderately rather than excessively upregulating lipid synthesis. The astaxanthin yield reached 9.79 mg/g DCW after lipid engineering and was further improved to 10.21 mg/g DCW by balancing the expression of β-carotene hydroxylase and ketolase. Finally, by combining spatial regulation through lipid droplet engineering and temporal regulation via temperature-responsive pathway expression, 446.4 mg/L astaxanthin was produced in fed-batch fermentation.
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Affiliation(s)
- Min Li
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Pingping Zhou
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.,College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Mingkai Chen
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Hongwei Yu
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Lidan Ye
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.,ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, China
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21
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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22
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Yang J, Liu J, Pan Y, Maréchal E, Amato A, Liu M, Gong Y, Li Y, Hu H. PDAT regulates PE as transient carbon sink alternative to triacylglycerol in Nannochloropsis. PLANT PHYSIOLOGY 2022; 189:1345-1362. [PMID: 35385114 PMCID: PMC9237688 DOI: 10.1093/plphys/kiac160] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/14/2022] [Indexed: 05/21/2023]
Abstract
Triacylglycerols (TAGs) are the main storage lipids in photosynthetic organisms under stress. In the oleaginous alga Nannochloropsis oceanica, while multiple acyl CoA:diacylglycerol (DAG) acyltransferases (NoDGATs) are involved in TAG production, the role of the unique phospholipid:DAG acyltransferase (NoPDAT) remains unknown. Here, we performed a functional complementation assay in TAG-deficient yeast (Saccharomyces cerevisiae) and an in vitro assay to probe the acyltransferase activity of NoPDAT. Subcellular localization, overexpression, and knockdown (KD) experiments were also conducted to elucidate the role of NoPDAT in N. oceanica. NoPDAT, residing at the outermost plastid membrane, does not phylogenetically fall into the clades of algae or plants and uses phosphatidylethanolamine (PE) and phosphatidylglycerol with 16:0, 16:1, and 18:1 at position sn-2 as acyl-donors in vivo. NoPDAT KD, not triggering any compensatory mechanism via DGATs, led to an ∼30% decrease of TAG content, accompanied by a vast accumulation of PEs rich in 16:0, 16:1, and 18:1 fatty acids (referred to as "LU-PE") that was positively associated with CO2 availability. We conclude that the NoPDAT pathway is parallel to and independent of the NoDGAT pathway for oil production. LU-PE can serve as an alternative carbon sink for photosynthetically assimilated carbon in N. oceanica when PDAT-mediated TAG biosynthesis is compromised or under stress in the presence of high CO2 levels.
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Affiliation(s)
| | | | - Yufang Pan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG‐LPCV, 38054 Grenoble Cedex 9, France
| | - Alberto Amato
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG‐LPCV, 38054 Grenoble Cedex 9, France
| | - Meijing Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Yangmin Gong
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Yantao Li
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland Baltimore County, Baltimore, Maryland 21202, USA
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23
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Chain flexibility of medicinal lipids determines their selective partitioning into lipid droplets. Nat Commun 2022; 13:3612. [PMID: 35750680 PMCID: PMC9232528 DOI: 10.1038/s41467-022-31400-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 06/15/2022] [Indexed: 11/20/2022] Open
Abstract
In guiding lipid droplets (LDs) to serve as storage vessels that insulate high-value lipophilic compounds in cells, we demonstrate that chain flexibility of lipids determines their selective migration in intracellular LDs. Focusing on commercially important medicinal lipids with biogenetic similarity but structural dissimilarity, we computationally and experimentally validate that LD remodeling should be differentiated between overproduction of structurally flexible squalene and that of rigid zeaxanthin and β-carotene. In molecular dynamics simulations, worm-like flexible squalene is readily deformed to move through intertwined chains of triacylglycerols in the LD core, whereas rod-like rigid zeaxanthin is trapped on the LD surface due to a high free energy barrier in diffusion. By designing yeast cells with either much larger LDs or with a greater number of LDs, we observe that intracellular storage of squalene significantly increases with LD volume expansion, but that of zeaxanthin and β-carotene is enhanced through LD surface broadening; as visually evidenced, the outcomes represent internal penetration of squalene and surface localization of zeaxanthin and β-carotene. Our study shows the computational and experimental validation of selective lipid migration into a phase-separated organelle and reveals LD dynamics and functionalization. Lipid droplet (LD) is a highly dynamic organelle capable of regulating lipid metabolism, storage and transportation. Here, by combining molecular dynamics simulations and microbial LD engineering, the authors demonstrate that the structural flexibility of lipids is one of decisive factors in selective partitioning into LDs.
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24
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Cheng D, Li L, Rizhsky L, Bhandary P, Nikolau BJ. Heterologous Expression and Characterization of Plant Wax Ester Producing Enzymes. Metabolites 2022; 12:metabo12070577. [PMID: 35888701 PMCID: PMC9319179 DOI: 10.3390/metabo12070577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 02/04/2023] Open
Abstract
Wax esters are widely distributed among microbes, plants, and mammals, and they serve protective and energy storage functions. Three classes of enzymes catalyze the reaction between a fatty acyl alcohol and a fatty acyl-CoA, generating wax esters. Multiple isozymes of two of these enzyme classes, the membrane-bound O-acyltransferase class of wax synthase (WS) and the bifunctional wax synthase/diacylglycerol acyl transferase (WSD), co-exist in plants. Although WSD enzymes are known to produce the wax esters of the plant cuticle, the functionality of plant WS enzymes is less well characterized. In this study, we investigated the phylogenetic relationships among the 12 WS and 11 WSD isozymes that occur in Arabidopsis, and established two in vivo heterologous expression systems, in the yeast Saccharomyces cerevisiae and in Arabidopsis seeds to investigate the catalytic abilities of the WS enzymes. These two refactored wax assembly chassis were used to demonstrate that WS isozymes show distinct differences in the types of esters that can be assembled. We also determined the cellular and subcellular localization of two Arabidopsis WS isozymes. Additionally, using publicly available Arabidopsis transcriptomics data, we identified the co-expression modules of the 12 Arabidopsis WS coding genes. Collectively, these analyses suggest that WS genes may function in cuticle assembly and in supporting novel photosynthetic function(s).
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Affiliation(s)
- Daolin Cheng
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA; (D.C.); (L.L.); (L.R.)
- Center for Metabolic Biology, Iowa State University, Ames, IA 50011, USA
| | - Ling Li
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA; (D.C.); (L.L.); (L.R.)
- Center for Metabolic Biology, Iowa State University, Ames, IA 50011, USA
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA;
- Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| | - Ludmila Rizhsky
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA; (D.C.); (L.L.); (L.R.)
- Center for Metabolic Biology, Iowa State University, Ames, IA 50011, USA
| | - Priyanka Bhandary
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA;
| | - Basil J. Nikolau
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA; (D.C.); (L.L.); (L.R.)
- Center for Metabolic Biology, Iowa State University, Ames, IA 50011, USA
- Correspondence: ; Tel.: +1-515-290-3382
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25
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He X, Guo X, Du Z, Liu X, Jing J, Zhou C, Cheng Y, Wang Z, He XP. Enhancement of Intracellular Accumulation of Copper by Biogenesis of Lipid Droplets in Saccharomyces cerevisiae Revealed by Transcriptomic Analysis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:7170-7179. [PMID: 35657321 DOI: 10.1021/acs.jafc.2c01071] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Copper is an essential micronutrient for life, whose homeostasis is rigorously regulated to meet the demands of normal biological processes and to minimize the potential toxicity. Copper enriched by yeast is regarded as a safe and bioavailable form of copper supplements. Here, a Saccharomyces cerevisiae mutant strain H247 with expanded storage capability of copper was obtained through atmospheric and room-temperature plasma treatment. Transcriptomic analyses found that transcriptional upregulation of DGA1 might be the major contributor to the enhancement of intracellular copper accumulation in strain H247. The positive correlation between biogenesis of lipid droplets and intracellular accumulation of copper was confirmed by overexpression of the diacylglycerol acyltransferase encoding genes DGA1 and LRO1 or knockout of DGA1. Lipid droplets are not only the storage pool of copper but might prompt the copper trafficking to mitochondria, vacuoles, and Golgi apparatus. These results provide new insights into the sophisticated copper homeostatic mechanisms and the biological functions of lipid droplets.
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Affiliation(s)
- Xiaoxian He
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100101, China
| | - Xuena Guo
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhengda Du
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100101, China
| | - Xuelian Liu
- State Key Laboratory of Direct-Fed Microbial Engineering, Beijing DaBeiNong Science and Technology Group Co., Ltd. (DBN), Beijing 100192, China
| | - Junnian Jing
- State Key Laboratory of Direct-Fed Microbial Engineering, Beijing DaBeiNong Science and Technology Group Co., Ltd. (DBN), Beijing 100192, China
| | - Chenyao Zhou
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100101, China
| | - Yanfei Cheng
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhaoyue Wang
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiu-Ping He
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100101, China
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26
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Chellamuthu M, Kumaresan K, Subramanian S. Increase in alpha-linolenic acid content by simultaneous expression of fatty acid metabolism genes in Sesame ( Sesamum indicum L.). PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2022; 28:559-572. [PMID: 35465201 PMCID: PMC8986930 DOI: 10.1007/s12298-022-01152-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 02/12/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
UNLABELLED Sesame is considered one of India's important sources of edible oil and an excellent dietary source for its nutritional and medicinal value. Sesame DGAT1 and PDAT1 genes were co-expressed with omega 3 FAD genes. Systemic isolation of sesame DGAT1, PDAT1, ER type FAD3, and chloroplast type FAD7/8 genes were performed. Their sequence was analyzed for genomic organization, amino acid characterization, organ specificity, and phylogenetic relationships. The insilico analysis revealed the unique features of DGAT1, PDAT1, and FAD3 gene sequences, whereas FAD7 and FAD8 sequences had the same protein characters and were grouped in phylogeny analysis, only variation was found in their mRNA UTR regions. Functional expression of sesame TAG synthesis genes and omega-3 FAD genes was studied in yeast mutant H1246 deficient for TAG synthesis. Functional analyses in yeast with the presence of ALA confirmed the identity of sesame FAD3, FAD7 and FAD8 genes. Recombinant expression of pESC + DGAT1 + FAD3 vector in yeast mutant resulted in lipid accumulation with 10% higher ALA content. Thus this gene combination can be co-expressed in sesame and other plant systems to increase the lipid accumulation with high omega-3 fatty acid (ALA) content. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-022-01152-0.
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Affiliation(s)
| | - Kanimozhi Kumaresan
- Department of Biotechnology, PSG College of Technology, 641004 Coimbatore, Tamil Nadu India
| | - Selvi Subramanian
- Department of Biotechnology, PSG College of Technology, 641004 Coimbatore, Tamil Nadu India
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27
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Wei H, Wang W, Knoshaug EP, Chen X, Van Wychen S, Bomble YJ, Himmel ME, Zhang M. Disruption of the Snf1 Gene Enhances Cell Growth and Reduces the Metabolic Burden in Cellulase-Expressing and Lipid-Accumulating Yarrowia lipolytica. Front Microbiol 2022; 12:757741. [PMID: 35003001 PMCID: PMC8733397 DOI: 10.3389/fmicb.2021.757741] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/19/2021] [Indexed: 12/01/2022] Open
Abstract
Yarrowia lipolytica is known to be capable of metabolizing glucose and accumulating lipids intracellularly; however, it lacks the cellulolytic enzymes needed to break down cellulosic biomass directly. To develop Y. lipolytica as a consolidated bioprocessing (CBP) microorganism, we previously expressed the heterologous CBH I, CBH II, and EG II cellulase enzymes both individually and collectively in this microorganism. We concluded that the coexpression of these cellulases resulted in a metabolic drain on the host cells leading to reduced cell growth and lipid accumulation. The current study aims to build a new cellulase coexpressing platform to overcome these hinderances by (1) knocking out the sucrose non-fermenting 1 (Snf1) gene that represses the energetically expensive lipid and protein biosynthesis processes, and (2) knocking in the cellulase cassette fused with the recyclable selection marker URA3 gene in the background of a lipid-accumulating Y. lipolytica strain overexpressing ATP citrate lyase (ACL) and diacylglycerol acyltransferase 1 (DGA1) genes. We have achieved a homologous recombination insertion rate of 58% for integrating the cellulases-URA3 construct at the disrupted Snf1 site in the genome of host cells. Importantly, we observed that the disruption of the Snf1 gene promoted cell growth and lipid accumulation and lowered the cellular saturated fatty acid level and the saturated to unsaturated fatty acid ratio significantly in the transformant YL163t that coexpresses cellulases. The result suggests a lower endoplasmic reticulum stress in YL163t, in comparison with its parent strain Po1g ACL-DGA1. Furthermore, transformant YL163t increased in vitro cellulolytic activity by 30%, whereas the “total in vivo newly formed FAME (fatty acid methyl esters)” increased by 16% in comparison with a random integrative cellulase-expressing Y. lipolytica mutant in the same YNB-Avicel medium. The Snf1 disruption platform demonstrated in this study provides a potent tool for the further development of Y. lipolytica as a robust host for the expression of cellulases and other commercially important proteins.
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Affiliation(s)
- Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Wei Wang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Eric P Knoshaug
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Xiaowen Chen
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Stefanie Van Wychen
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States.,National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Yannick J Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Michael E Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
| | - Min Zhang
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, United States
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28
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Teixeira V, Martins TS, Prinz WA, Costa V. Target of Rapamycin Complex 1 (TORC1), Protein Kinase A (PKA) and Cytosolic pH Regulate a Transcriptional Circuit for Lipid Droplet Formation. Int J Mol Sci 2021; 22:9017. [PMID: 34445723 PMCID: PMC8396576 DOI: 10.3390/ijms22169017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/12/2021] [Accepted: 08/19/2021] [Indexed: 11/16/2022] Open
Abstract
Lipid droplets (LDs) are ubiquitous organelles that fulfill essential roles in response to metabolic cues. The identification of several neutral lipid synthesizing and regulatory protein complexes have propelled significant advance on the mechanisms of LD biogenesis in the endoplasmic reticulum (ER). However, our understanding of signaling networks, especially transcriptional mechanisms, regulating membrane biogenesis is very limited. Here, we show that the nutrient-sensing Target of Rapamycin Complex 1 (TORC1) regulates LD formation at a transcriptional level, by targeting DGA1 expression, in a Sit4-, Mks1-, and Sfp1-dependent manner. We show that cytosolic pH (pHc), co-regulated by the plasma membrane H+-ATPase Pma1 and the vacuolar ATPase (V-ATPase), acts as a second messenger, upstream of protein kinase A (PKA), to adjust the localization and activity of the major transcription factor repressor Opi1, which in turn controls the metabolic switch between phospholipid metabolism and lipid storage. Together, this work delineates hitherto unknown molecular mechanisms that couple nutrient availability and pHc to LD formation through a transcriptional circuit regulated by major signaling transduction pathways.
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Affiliation(s)
- Vitor Teixeira
- Yeast Signalling Networks, i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (T.S.M.); (V.C.)
- Yeast Signalling Networks, IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Telma S. Martins
- Yeast Signalling Networks, i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (T.S.M.); (V.C.)
- Yeast Signalling Networks, IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS—Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - William A. Prinz
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA;
| | - Vítor Costa
- Yeast Signalling Networks, i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (T.S.M.); (V.C.)
- Yeast Signalling Networks, IBMC—Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS—Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
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29
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Cottier S, Schneiter R. Lipid droplets form a network interconnected by the endoplasmic reticulum through which their proteins equilibrate. J Cell Sci 2021; 135:271208. [PMID: 34373922 DOI: 10.1242/jcs.258819] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/03/2021] [Indexed: 01/13/2023] Open
Abstract
Lipid droplets (LDs) are globular intracellular structures dedicated to the storage of neutral lipids. They are closely associated with the endoplasmic reticulum (ER) and are delineated by a monolayer of phospholipids that is continuous with the cytoplasmic leaflet of the ER membrane. LDs contain a specific set of proteins, but how these proteins are targeted to the LD surface is not fully understood. Here, we devised a yeast mating-based microscopic readout to monitor the transfer of LD proteins upon zygote formation. The results of this analysis indicate that ER fusion between mating partners is required for transfer of LD proteins and that this transfer is continuous, bidirectional and affects most LDs simultaneously. These observations suggest that LDs do not fuse upon mating of yeast cells, but that they form a network that is interconnected through the ER membrane. Consistent with this, ER-localized LD proteins rapidly move onto LDs of a mating partner and this protein transfer is affected by seipin, a protein important for proper LD biogenesis and the functional connection of LDs with the ER membrane.
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Affiliation(s)
- Stéphanie Cottier
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Roger Schneiter
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
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30
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Rahman MA, Kumar R, Sanchez E, Nazarko TY. Lipid Droplets and Their Autophagic Turnover via the Raft-Like Vacuolar Microdomains. Int J Mol Sci 2021; 22:8144. [PMID: 34360917 PMCID: PMC8348048 DOI: 10.3390/ijms22158144] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 01/01/2023] Open
Abstract
Although once perceived as inert structures that merely serve for lipid storage, lipid droplets (LDs) have proven to be the dynamic organelles that hold many cellular functions. The LDs' basic structure of a hydrophobic core consisting of neutral lipids and enclosed in a phospholipid monolayer allows for quick lipid accessibility for intracellular energy and membrane production. Whereas formed at the peripheral and perinuclear endoplasmic reticulum, LDs are degraded either in the cytosol by lipolysis or in the vacuoles/lysosomes by autophagy. Autophagy is a regulated breakdown of dysfunctional, damaged, or surplus cellular components. The selective autophagy of LDs is called lipophagy. Here, we review LDs and their degradation by lipophagy in yeast, which proceeds via the micrometer-scale raft-like lipid domains in the vacuolar membrane. These vacuolar microdomains form during nutrient deprivation and facilitate internalization of LDs via the vacuolar membrane invagination and scission. The resultant intra-vacuolar autophagic bodies with LDs inside are broken down by vacuolar lipases and proteases. This type of lipophagy is called microlipophagy as it resembles microautophagy, the type of autophagy when substrates are sequestered right at the surface of a lytic compartment. Yeast microlipophagy via the raft-like vacuolar microdomains is a great model system to study the role of lipid domains in microautophagic pathways.
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Affiliation(s)
- Muhammad Arifur Rahman
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA; (M.A.R.); (E.S.)
| | - Ravinder Kumar
- Department of Obstetrics, Gynecology and Reproductive Science, University of California, San Francisco, CA 94143, USA;
| | - Enrique Sanchez
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA; (M.A.R.); (E.S.)
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Taras Y. Nazarko
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA; (M.A.R.); (E.S.)
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31
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Brink JTR, Fourie R, Sebolai O, Albertyn J, Pohl CH. The role of lipid droplets in microbial pathogenesis. J Med Microbiol 2021; 70. [PMID: 34184983 DOI: 10.1099/jmm.0.001383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The nonpolar lipids present in cells are mainly triacylglycerols and steryl esters. When cells are provided with an abundance of nutrients, these storage lipids accumulate. As large quantities of nonpolar lipids cannot be integrated into membranes, they are isolated from the cytosolic environment in lipid droplets. As specialized, inducible cytoplasmic organelles, lipid droplets have functions beyond the regulation of lipid metabolism, in cell signalling and activation, membrane trafficking and control of inflammatory mediator synthesis and secretion. Pathogens, including fungi, viruses, parasites, or intracellular bacteria can induce and may benefit from lipid droplets in infected cells. Here we review biogenesis of lipid droplets as well as the role of lipid droplets in the pathogenesis of selected viruses, bacteria, protists and yeasts.
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Affiliation(s)
- Jacobus T R Brink
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Ruan Fourie
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Olihile Sebolai
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Jacobus Albertyn
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Carolina H Pohl
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
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32
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Chattopadhyay A, Maiti MK. Lipid production by oleaginous yeasts. ADVANCES IN APPLIED MICROBIOLOGY 2021; 116:1-98. [PMID: 34353502 DOI: 10.1016/bs.aambs.2021.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Microbial lipid production has been studied extensively for years; however, lipid metabolic engineering in many of the extraordinarily high lipid-accumulating yeasts was impeded by inadequate understanding of the metabolic pathways including regulatory mechanisms defining their oleaginicity and the limited genetic tools available. The aim of this review is to highlight the prominent oleaginous yeast genera, emphasizing their oleaginous characteristics, in conjunction with diverse other features such as cheap carbon source utilization, withstanding the effect of inhibitory compounds, commercially favorable fatty acid composition-all supporting their future development as economically viable lipid feedstock. The unique aspects of metabolism attributing to their oleaginicity are accentuated in the pretext of outlining the various strategies successfully implemented to improve the production of lipid and lipid-derived metabolites. A large number of in silico data generated on the lipid accumulation in certain oleaginous yeasts have been carefully curated, as suggestive evidences in line with the exceptional oleaginicity of these organisms. The different genetic elements developed in these yeasts to execute such strategies have been scrupulously inspected, underlining the major types of newly-found and synthetically constructed promoters, transcription terminators, and selection markers. Additionally, there is a plethora of advanced genetic toolboxes and techniques described, which have been successfully used in oleaginous yeasts in the recent years, promoting homologous recombination, genome editing, DNA assembly, and transformation at remarkable efficiencies. They can accelerate and effectively guide the rational designing of system-wide metabolic engineering approaches pinpointing the key targets for developing industrially suitable yeast strains.
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Affiliation(s)
- Atrayee Chattopadhyay
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India
| | - Mrinal K Maiti
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, India.
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33
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Becuwe M, Bond LM, Pinto AFM, Boland S, Mejhert N, Elliott SD, Cicconet M, Graham MM, Liu XN, Ilkayeva O, Saghatelian A, Walther TC, Farese RV. FIT2 is an acyl-coenzyme A diphosphatase crucial for endoplasmic reticulum homeostasis. J Cell Biol 2021; 219:152082. [PMID: 32915949 PMCID: PMC7659722 DOI: 10.1083/jcb.202006111] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 12/13/2022] Open
Abstract
The endoplasmic reticulum is a cellular hub of lipid metabolism, coordinating lipid synthesis with continuous changes in metabolic flux. Maintaining ER lipid homeostasis despite these fluctuations is crucial to cell function and viability. Here, we identify a novel mechanism that is crucial for normal ER lipid metabolism and protects the ER from dysfunction. We identify the molecular function of the evolutionarily conserved ER protein FIT2 as a fatty acyl–coenzyme A (CoA) diphosphatase that hydrolyzes fatty acyl–CoA to yield acyl 4′-phosphopantetheine. This activity of FIT2, which is predicted to be active in the ER lumen, is required in yeast and mammalian cells for maintaining ER structure, protecting against ER stress, and enabling normal lipid storage in lipid droplets. Our findings thus solve the long-standing mystery of the molecular function of FIT2 and highlight the maintenance of optimal fatty acyl–CoA levels as key to ER homeostasis.
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Affiliation(s)
- Michel Becuwe
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA.,Department of Cell Biology, Harvard Medical School, Boston, MA.,Broad Institute of MIT and Harvard, Cambridge, MA
| | - Laura M Bond
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA.,Department of Cell Biology, Harvard Medical School, Boston, MA.,Broad Institute of MIT and Harvard, Cambridge, MA
| | - Antonio F M Pinto
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA
| | - Sebastian Boland
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA.,Department of Cell Biology, Harvard Medical School, Boston, MA.,Broad Institute of MIT and Harvard, Cambridge, MA
| | - Niklas Mejhert
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA.,Department of Cell Biology, Harvard Medical School, Boston, MA.,Broad Institute of MIT and Harvard, Cambridge, MA
| | - Shane D Elliott
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA.,Department of Cell Biology, Harvard Medical School, Boston, MA.,Broad Institute of MIT and Harvard, Cambridge, MA.,Howard Hughes Medical Institute, Boston, MA
| | - Marcelo Cicconet
- Image and Data Analysis Core, Harvard Medical School, Boston, MA
| | - Morven M Graham
- Center for Cellular and Molecular Imaging, Department of Cell Biology, Yale School of Medicine, New Haven, CT
| | - Xinran N Liu
- Center for Cellular and Molecular Imaging, Department of Cell Biology, Yale School of Medicine, New Haven, CT
| | - Olga Ilkayeva
- Departments of Medicine and Pharmacology and Cancer Biology, Sarah W. Stedman Nutrition and Metabolism Center and Duke Molecular Physiology Institute, Duke University, Durham, NC
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA
| | - Tobias C Walther
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA.,Department of Cell Biology, Harvard Medical School, Boston, MA.,Broad Institute of MIT and Harvard, Cambridge, MA.,Howard Hughes Medical Institute, Boston, MA
| | - Robert V Farese
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA.,Department of Cell Biology, Harvard Medical School, Boston, MA.,Broad Institute of MIT and Harvard, Cambridge, MA
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34
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Schepers J, Behl C. Lipid droplets and autophagy-links and regulations from yeast to humans. J Cell Biochem 2021; 122:602-611. [PMID: 33522032 DOI: 10.1002/jcb.29889] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/04/2020] [Accepted: 12/28/2020] [Indexed: 12/22/2022]
Abstract
Recent advances in the yeast Saccharomyces cerevisiae and higher eukaryotes have been increasingly connecting lipid droplet (LD) dynamics to the regulation of autophagy. In this review we will discuss implications that connect LD de novo synthesis and LD mobilization to autophagy and how autophagy is regulated by these mechanisms. Elucidating these connections might pose a chance to further understand autophagy induction and membrane biogenesis for the growing autophagosome under different conditions. Increasing our understanding of these mechanisms might provide a chance to understand several conditions that might be related to LD dysregulation and, possibly, as a consequence of this, dysregulation of autophagy.
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Affiliation(s)
- Jana Schepers
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christian Behl
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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35
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Lord CL, Wente SR. Nuclear envelope-vacuole contacts mitigate nuclear pore complex assembly stress. J Cell Biol 2020; 219:211463. [PMID: 33053148 PMCID: PMC7563749 DOI: 10.1083/jcb.202001165] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 08/10/2020] [Accepted: 09/23/2020] [Indexed: 01/04/2023] Open
Abstract
The intricacy of nuclear pore complex (NPC) biogenesis imposes risks of failure that can cause defects in nuclear transport and nuclear envelope (NE) morphology; however, cellular mechanisms used to alleviate NPC assembly stress are not well defined. In the budding yeast Saccharomyces cerevisiae, we demonstrate that NVJ1- and MDM1-enriched NE-vacuole contacts increase when NPC assembly is compromised in several nup mutants, including nup116ΔGLFG cells. These interorganelle nucleus-vacuole junctions (NVJs) cooperate with lipid droplets to maintain viability and enhance NPC formation in assembly mutants. Additionally, NVJs function with ATG1 to remodel the NE and promote vacuole-dependent degradation of specific nucleoporins in nup116ΔGLFG cells. Importantly, NVJs significantly improve the physiology of NPC assembly mutants, despite having only negligible effects when NPC biogenesis is unperturbed. These results therefore define how NE-vacuole interorganelle contacts coordinate responses to mitigate deleterious cellular effects caused by disrupted NPC assembly.
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Garcia EJ, Liao PC, Tan G, Vevea JD, Sing CN, Tsang CA, McCaffery JM, Boldogh IR, Pon LA. Membrane dynamics and protein targets of lipid droplet microautophagy during ER stress-induced proteostasis in the budding yeast, Saccharomyces cerevisiae. Autophagy 2020. [PMID: 33021864 DOI: 10.1080/15548627.2020.1826691.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022] Open
Abstract
Our previous studies reveal a mechanism for lipid droplet (LD)-mediated proteostasis in the endoplasmic reticulum (ER) whereby unfolded proteins that accumulate in the ER in response to lipid imbalance-induced ER stress are removed by LDs and degraded by microlipophagy (µLP), autophagosome-independent LD uptake into the vacuole (the yeast lysosome). Here, we show that dithiothreitol- or tunicamycin-induced ER stress also induces µLP and identify an unexpected role for vacuolar membrane dynamics in this process. All stressors studied induce vacuolar fragmentation prior to µLP. Moreover, during µLP, fragmented vacuoles fuse to form cup-shaped structures that encapsulate and ultimately take up LDs. Our studies also indicate that proteins of the endosome sorting complexes required for transport (ESCRT) are upregulated, required for µLP, and recruited to LDs, vacuolar membranes, and sites of vacuolar membrane scission during µLP. We identify possible target proteins for LD-mediated ER proteostasis. Our live-cell imaging studies reveal that one potential target (Nup159) localizes to punctate structures that colocalizes with LDs 1) during movement from ER membranes to the cytosol, 2) during microautophagic uptake into vacuoles, and 3) within the vacuolar lumen. Finally, we find that mutations that inhibit LD biogenesis, homotypic vacuolar membrane fusion or ESCRT function inhibit stress-induced autophagy of Nup159 and other ER proteins. Thus, we have obtained the first direct evidence that LDs and µLP can mediate ER stress-induced ER proteostasis, and identified direct roles for ESCRT and vacuolar membrane fusion in that process.
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Affiliation(s)
- Enrique J Garcia
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Pin-Chao Liao
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Gary Tan
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Jason D Vevea
- HHMI and Department of Neuroscience, University of Wisconsin, Madison, Wisconsin, USA
| | - Cierra N Sing
- Institute of Human Nutrition, Columbia University, New York, NY, USA
| | - Catherine A Tsang
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - J Michael McCaffery
- Integrated Imaging Center, Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Istvan R Boldogh
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Liza A Pon
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
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Garcia EJ, Liao PC, Tan G, Vevea JD, Sing CN, Tsang CA, McCaffery JM, Boldogh IR, Pon LA. Membrane dynamics and protein targets of lipid droplet microautophagy during ER stress-induced proteostasis in the budding yeast, Saccharomyces cerevisiae. Autophagy 2020; 17:2363-2383. [PMID: 33021864 PMCID: PMC8496710 DOI: 10.1080/15548627.2020.1826691] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Our previous studies reveal a mechanism for lipid droplet (LD)-mediated proteostasis in the endoplasmic reticulum (ER) whereby unfolded proteins that accumulate in the ER in response to lipid imbalance-induced ER stress are removed by LDs and degraded by microlipophagy (µLP), autophagosome-independent LD uptake into the vacuole (the yeast lysosome). Here, we show that dithiothreitol- or tunicamycin-induced ER stress also induces µLP and identify an unexpected role for vacuolar membrane dynamics in this process. All stressors studied induce vacuolar fragmentation prior to µLP. Moreover, during µLP, fragmented vacuoles fuse to form cup-shaped structures that encapsulate and ultimately take up LDs. Our studies also indicate that proteins of the endosome sorting complexes required for transport (ESCRT) are upregulated, required for µLP, and recruited to LDs, vacuolar membranes, and sites of vacuolar membrane scission during µLP. We identify possible target proteins for LD-mediated ER proteostasis. Our live-cell imaging studies reveal that one potential target (Nup159) localizes to punctate structures that colocalizes with LDs 1) during movement from ER membranes to the cytosol, 2) during microautophagic uptake into vacuoles, and 3) within the vacuolar lumen. Finally, we find that mutations that inhibit LD biogenesis, homotypic vacuolar membrane fusion or ESCRT function inhibit stress-induced autophagy of Nup159 and other ER proteins. Thus, we have obtained the first direct evidence that LDs and µLP can mediate ER stress-induced ER proteostasis, and identified direct roles for ESCRT and vacuolar membrane fusion in that process.
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Affiliation(s)
- Enrique J Garcia
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Pin-Chao Liao
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Gary Tan
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Jason D Vevea
- HHMI and Department of Neuroscience, University of Wisconsin, Madison, Wisconsin, USA
| | - Cierra N Sing
- Institute of Human Nutrition, Columbia University, New York, NY, USA
| | - Catherine A Tsang
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - J Michael McCaffery
- Integrated Imaging Center, Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Istvan R Boldogh
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Liza A Pon
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
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Hapala I, Griac P, Holic R. Metabolism of Storage Lipids and the Role of Lipid Droplets in the Yeast Schizosaccharomyces pombe. Lipids 2020; 55:513-535. [PMID: 32930427 DOI: 10.1002/lipd.12275] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/14/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022]
Abstract
Storage lipids, triacylglycerols (TAG), and steryl esters (SE), are predominant constituents of lipid droplets (LD) in fungi. In several yeast species, metabolism of TAG and SE is linked to various cellular processes, including cell division, sporulation, apoptosis, response to stress, and lipotoxicity. In addition, TAG are an important source for the generation of value-added lipids for industrial and biomedical applications. The fission yeast Schizosaccharomyces pombe is a widely used unicellular eukaryotic model organism. It is a powerful tractable system used to study various aspects of eukaryotic cellular and molecular biology. However, the knowledge of S. pombe neutral lipids metabolism is quite limited. In this review, we summarize and discuss the current knowledge of the homeostasis of storage lipids and of the role of LD in the fission yeast S. pombe with the aim to stimulate research of lipid metabolism and its connection with other essential cellular processes. We also discuss the advantages and disadvantages of fission yeast in lipid biotechnology and recent achievements in the use of S. pombe in the biotechnological production of valuable lipid compounds.
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Affiliation(s)
- Ivan Hapala
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
| | - Peter Griac
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
| | - Roman Holic
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
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Zhou B, Fei W, Yang S, Yang F, Qu G, Tang W, Ou J, Peng D. Alteration of the fatty acid composition of Brassica napus L. via overexpression of phospholipid: Diacylglycerol acyltransferase 1 from Sapium sebiferum (L.) Roxb. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 298:110562. [PMID: 32771163 DOI: 10.1016/j.plantsci.2020.110562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 06/11/2023]
Abstract
Sapium sebiferum (L.) Roxb. plays an important role in traditional Chinese medicine and is one of major woody oil tree in China. Phospholipid: diacylglycerol acyltransferase 1 (PDAT1), as an important catalytic enzyme for the formation of triacylglycerol (TAG), is mainly responsible for the transfer of an acyl group from the sn-2 position of phospholipids to the sn-3 position of sn-1, 2-diacylglycerol (DAG) to produce TAG and sn-1 lysophospholipids. The importance of PDAT1 in triacylglycerol biosynthesis has been illustrated in previous research, and at least 67 PDAT1 sequences have been identified from 31 organisms. However, little is known about the gene encoding PDAT1 in S. sebiferum (SsPDAT1), which is involved in seed oil biosynthesis. To explore the functional characteristics of SsPDAT1, we cloned and analyzed the full-length cDNA in the coding region of SsPDAT1, which consists of 2040 bp and encodes a putative protein of 680 amino acid (aa) residues. Thin-layer chromatography (TLC) analysis showed that recombinant SsPDAT1 could restore TAG accumulation in TAG-deficient mutant yeast (Saccharomyces cerevisiae) H1246, which revealed the enzyme activity of SsPDAT1. Moreover, transgenic Brassica napus L. W10 plants overexpressing SsPDAT1 showed significant increases of 19.6-28.9 % in linoleic acid levels but decreases of 27.3-37.1 % in linolenic acid. Furthermore, the total oil content increased by 8.1 %-10.8 % in SsPDAT1 transgenic seeds. These results confirmed the role of SsPDAT1 in stabilizing oil biosynthesis and suggested that SsPDAT1 could be exploitable to specifically regulate the oil composition of plants. These experimental results provide a new concept that may enable the industrial development of plants with high-linoleic-acid oil through overexpression of SsPDAT1 in S. sebiferum L.
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Affiliation(s)
- Bo Zhou
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China; Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, 410018, Changsha, China; Forestry Biotechnology Hunan Key Laboratories, Hunan, Changsha, 410004, China; National Engineering Laboratory of Applied Technology for Forestry and Ecology in Southern China, Changsha, 410004, Hunan, China; Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem in Hunan Province, Huitong, 438107, China.
| | - Wenjie Fei
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Shiquan Yang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Feng Yang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Gaoyi Qu
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Weiwei Tang
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Jianping Ou
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China
| | - Dan Peng
- Faculty of Bioscience and Biotechnology of Central South University of Forestry and Technology, 410004, Changsha, China; Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, 410018, Changsha, China.
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40
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Li D, Yang SG, He CW, Zhang ZT, Liang Y, Li H, Zhu J, Su X, Gong Q, Xie Z. Excess diacylglycerol at the endoplasmic reticulum disrupts endomembrane homeostasis and autophagy. BMC Biol 2020; 18:107. [PMID: 32859196 PMCID: PMC7453538 DOI: 10.1186/s12915-020-00837-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/24/2020] [Indexed: 01/22/2023] Open
Abstract
Background When stressed, eukaryotic cells produce triacylglycerol (TAG) to store nutrients and mobilize autophagy to combat internal damage. We and others previously reported that in yeast, elimination of TAG synthesizing enzymes inhibits autophagy under nitrogen starvation, yet the underlying mechanism has remained elusive. Results Here, we show that disruption of TAG synthesis led to diacylglycerol (DAG) accumulation and its relocation from the vacuolar membrane to the endoplasmic reticulum (ER). We further show that, beyond autophagy, ER-accumulated DAG caused severe defects in the endomembrane system, including disturbing the balance of ER-Golgi protein trafficking, manifesting in bulging of ER and loss of the Golgi apparatus. Genetic or chemical manipulations that increase consumption or decrease supply of DAG reversed these defects. In contrast, increased amounts of precursors of glycerolipid synthesis, including phosphatidic acid and free fatty acids, did not replicate the effects of excess DAG. We also provide evidence that the observed endomembrane defects do not rely on Golgi-produced DAG, Pkc1 signaling, or the unfolded protein response. Conclusions This work identifies DAG as the critical lipid molecule responsible for autophagy inhibition under condition of defective TAG synthesis and demonstrates the disruption of ER and Golgi function by excess DAG as the potential cause of the autophagy defect.
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Affiliation(s)
- Dan Li
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Shu-Gao Yang
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu, People's Republic of China
| | - Cheng-Wen He
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Zheng-Tan Zhang
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Yongheng Liang
- College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China
| | - Hui Li
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Jing Zhu
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China
| | - Xiong Su
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, Jiangsu, People's Republic of China.
| | - Qingqiu Gong
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China.
| | - Zhiping Xie
- State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, #800 Dong-Chuan Road, Shanghai, 200240, People's Republic of China.
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41
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Choudhary V, El Atab O, Mizzon G, Prinz WA, Schneiter R. Seipin and Nem1 establish discrete ER subdomains to initiate yeast lipid droplet biogenesis. J Cell Biol 2020; 219:e201910177. [PMID: 32349126 PMCID: PMC7337503 DOI: 10.1083/jcb.201910177] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/26/2020] [Accepted: 04/03/2020] [Indexed: 02/03/2023] Open
Abstract
Lipid droplets (LDs) are fat storage organelles that originate from the endoplasmic reticulum (ER). Relatively little is known about how sites of LD formation are selected and which proteins/lipids are necessary for the process. Here, we show that LDs induced by the yeast triacylglycerol (TAG)-synthases Lro1 and Dga1 are formed at discrete ER subdomains defined by seipin (Fld1), and a regulator of diacylglycerol (DAG) production, Nem1. Fld1 and Nem1 colocalize to ER-LD contact sites. We find that Fld1 and Nem1 localize to ER subdomains independently of each other and of LDs, but both are required for the subdomains to recruit the TAG-synthases and additional LD biogenesis factors: Yft2, Pex30, Pet10, and Erg6. These subdomains become enriched in DAG. We conclude that Fld1 and Nem1 are both necessary to recruit proteins to ER subdomains where LD biogenesis occurs.
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Affiliation(s)
- Vineet Choudhary
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Ola El Atab
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Giulia Mizzon
- Electron Microscopy Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - William A. Prinz
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Roger Schneiter
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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42
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Ranganathan PR, Nawada N, Narayanan AK, Rao DKV. Triglyceride deficiency and diacylglycerol kinase1 activity lead to the upregulation of mevalonate pathway in yeast: A study for the development of potential yeast platform for improved production of triterpenoid. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158661. [PMID: 32058036 DOI: 10.1016/j.bbalip.2020.158661] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 12/19/2022]
Abstract
Besides energy storage and membrane biogenesis, lipids are known for their numerous biological functions. The two essential lipids, diacylglycerol (DG) and phosphatidic acid (PA), are shown to be associated with cell signalling processes. In this study, we examined whether triglyceride-deficient yeast mutants (tgΔ), dga1Δ and dga1Δlro1Δ, may play an important role in mevalonate (MEV) pathway regulation. Our metabolite analyses revealed that tgΔ cells showed high levels of squalene (SQ) and ergosterol (ERG), which are key indicators of MEV pathway activity. In addition, gene expression studies indicated that the MEV pathway genes in tgΔ cells were significantly upregulated. Interestingly, tgΔ cells exhibited high diacylglycerol kinase1 (DGK1) expression. Furthermore, DGK1 overexpression in WT and tgΔ phenotypes causes a substantial elevation in SQ and ERG levels, and we also found a significant increase in transcript levels of MEV pathway genes, confirming the new role of DGK1 in MEV pathway regulation. This suggests that high DG phosphorylation activity increases the PA pool that may induce the upregulation of MEV pathway in tgΔ cells. The induced MEV pathway is one of the key strategies in the field of synthetic biology for improved production of terpenoids in yeast. Thus, to examine whether increased endogenous MEV pathway flux can be redirected to triterpenoid, β-Amyrin synthase gene was heterologously expressed in DGK1 overexpressing tgΔ cells that led to significant production of β-Amyrin, a natural triterpenoid. In conclusion, our findings provide a novel strategy to increase MEV pathway precursors by modulating endogenous signal lipids for improved production of terpenoids.
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Affiliation(s)
- Poornima Ramani Ranganathan
- Biochemistry Laboratory, CSIR-Central Institute of Medicinal & Aromatic Plants, Research Center, Allalasandra, GKVK (post), Bangalore 560065, India; Academy of Scientific and Innovative Research (AcSIR), Sector 19, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh 201 002, India
| | - Niveditha Nawada
- Biochemistry Laboratory, CSIR-Central Institute of Medicinal & Aromatic Plants, Research Center, Allalasandra, GKVK (post), Bangalore 560065, India
| | - Ananth Krishna Narayanan
- Biochemistry Laboratory, CSIR-Central Institute of Medicinal & Aromatic Plants, Research Center, Allalasandra, GKVK (post), Bangalore 560065, India
| | - D K Venkata Rao
- Biochemistry Laboratory, CSIR-Central Institute of Medicinal & Aromatic Plants, Research Center, Allalasandra, GKVK (post), Bangalore 560065, India; Academy of Scientific and Innovative Research (AcSIR), Sector 19, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh 201 002, India.
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43
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Kwiatek JM, Han GS, Carman GM. Phosphatidate-mediated regulation of lipid synthesis at the nuclear/endoplasmic reticulum membrane. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158434. [PMID: 30910690 PMCID: PMC6755077 DOI: 10.1016/j.bbalip.2019.03.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 03/14/2019] [Indexed: 12/11/2022]
Abstract
In yeast and higher eukaryotes, phospholipids and triacylglycerol are derived from phosphatidate at the nuclear/endoplasmic reticulum membrane. In de novo biosynthetic pathways, phosphatidate is channeled into membrane phospholipids via its conversion to CDP-diacylglycerol. Its dephosphorylation to diacylglycerol is required for the synthesis of triacylglycerol as well as for the synthesis of phosphatidylcholine and phosphatidylethanolamine via the Kennedy pathway. In addition to the role of phosphatidate as a precursor, it is a regulatory molecule in the transcriptional control of phospholipid synthesis genes via the Henry regulatory circuit. Pah1 phosphatidate phosphatase and Dgk1 diacylglycerol kinase are key players that function counteractively in the control of the phosphatidate level at the nuclear/endoplasmic reticulum membrane. Loss of Pah1 phosphatidate phosphatase activity not only affects triacylglycerol synthesis but also disturbs the balance of the phosphatidate level, resulting in the alteration of lipid synthesis and related cellular defects. The pah1Δ phenotypes requiring Dgk1 diacylglycerol kinase exemplify the importance of the phosphatidate level in the misregulation of cellular processes. The catalytic function of Pah1 requires its translocation from the cytoplasm to the nuclear/endoplasmic reticulum membrane, which is regulated through its phosphorylation in the cytoplasm by multiple protein kinases as well as through its dephosphorylation by the membrane-associated Nem1-Spo7 protein phosphatase complex. This article is part of a Special Issue entitled Endoplasmic reticulum platforms for lipid dynamics edited by Shamshad Cockcroft and Christopher Stefan.
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Affiliation(s)
- Joanna M Kwiatek
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ 08901, USA
| | - Gil-Soo Han
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ 08901, USA
| | - George M Carman
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ 08901, USA.
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44
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Shao Q, Liu X, Su T, Ma C, Wang P. New Insights Into the Role of Seed Oil Body Proteins in Metabolism and Plant Development. FRONTIERS IN PLANT SCIENCE 2019; 10:1568. [PMID: 31921234 PMCID: PMC6914826 DOI: 10.3389/fpls.2019.01568] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 11/08/2019] [Indexed: 05/10/2023]
Abstract
Oil bodies (OBs) are ubiquitous dynamic organelles found in plant seeds. They have attracted increasing attention recently because of their important roles in plant physiology. First, the neutral lipids stored within these organelles serve as an initial, essential source of energy and carbon for seed germination and post-germinative growth of the seedlings. Secondly, they are involved in many other cellular processes such as stress responses, lipid metabolism, organ development, and hormone signaling. The biological functions of seed OBs are dependent on structural proteins, principally oleosins, caleosins, and steroleosins, which are embedded in the OB phospholipid monolayer. Oleosin and caleosin proteins are specific to plants and mainly act as OB structural proteins and are important for the biogenesis, stability, and dynamics of the organelle; whereas steroleosin proteins are also present in mammals and play an important role in steroid hormone metabolism and signaling. Significant progress using new genetic, biochemical, and imaging technologies has uncovered the roles of these proteins. Here, we review recent work on the structural or metabolic roles of these proteins in OB biogenesis, stabilization and degradation, lipid homeostasis and mobilization, hormone signal transduction, stress defenses, and various aspects of plant growth and development.
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Affiliation(s)
| | | | | | - Changle Ma
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Pingping Wang
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan, China
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45
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Barbosa AD, Lim K, Mari M, Edgar JR, Gal L, Sterk P, Jenkins BJ, Koulman A, Savage DB, Schuldiner M, Reggiori F, Wigge PA, Siniossoglou S. Compartmentalized Synthesis of Triacylglycerol at the Inner Nuclear Membrane Regulates Nuclear Organization. Dev Cell 2019; 50:755-766.e6. [PMID: 31422915 PMCID: PMC6859503 DOI: 10.1016/j.devcel.2019.07.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 04/22/2019] [Accepted: 07/03/2019] [Indexed: 01/08/2023]
Abstract
Cells dynamically adjust organelle organization in response to growth and environmental cues. This requires regulation of synthesis of phospholipids, the building blocks of organelle membranes, or remodeling of their fatty-acyl (FA) composition. FAs are also the main components of triacyglycerols (TGs), which enable energy storage in lipid droplets. How cells coordinate FA metabolism with organelle biogenesis during cell growth remains unclear. Here, we show that Lro1, an acyltransferase that generates TGs from phospholipid-derived FAs in yeast, relocates from the endoplasmic reticulum to a subdomain of the inner nuclear membrane. Lro1 nuclear targeting is regulated by cell cycle and nutrient starvation signals and is inhibited when the nucleus expands. Lro1 is active at this nuclear subdomain, and its compartmentalization is critical for nuclear integrity. These data suggest that Lro1 nuclear targeting provides a site of TG synthesis, which is coupled with nuclear membrane remodeling. Nutrients regulate the phospholipid:diacylglycerol acyltransferase Lro1 Lro1 targets the INM subdomain bordering the nucleolus Lro1 is active at the INM and can sustain cell survival during starvation Compartmentalized synthesis of nuclear TG is important for nuclear envelope integrity
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Affiliation(s)
- Antonio D Barbosa
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Koini Lim
- Metabolic Research Laboratories, Wellcome Trust-Medical Research, Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Muriel Mari
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, 9713AV Groningen, Netherlands
| | - James R Edgar
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Lihi Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Peter Sterk
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Benjamin J Jenkins
- NIHR BRC Core Metabolomics and Lipidomics Laboratory and University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, UK
| | - Albert Koulman
- NIHR BRC Core Metabolomics and Lipidomics Laboratory and University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge CB2 0QQ, UK
| | - David B Savage
- Metabolic Research Laboratories, Wellcome Trust-Medical Research, Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Fulvio Reggiori
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, 9713AV Groningen, Netherlands
| | - Philip A Wigge
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK
| | - Symeon Siniossoglou
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK.
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The biogenesis of lipid droplets: Lipids take center stage. Prog Lipid Res 2019; 75:100989. [PMID: 31351098 DOI: 10.1016/j.plipres.2019.100989] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/21/2019] [Accepted: 06/27/2019] [Indexed: 11/20/2022]
Abstract
Lipid droplets (LDs) are multi-functional cellular organelles that store energy, and regulate many aspects of cell physiology. However, our understanding of the biogenesis of LDs remains very limited. Originating from the endoplasmic reticulum (ER), LDs are highly unique organelles in that each LD is bounded by a monolayer of amphipathic lipids. Recent progress has unveiled critical roles of non-bilayer lipids in LD formation. For instance, non-bilayer lipids such as lysophospholipids, diacylglycerol and phosphatidic acid (PA) can impact the curvature, surface and line tension of the ER, thereby impacting LD biogenesis. Two well-known regulators of LD formation, FIT2/FITM2 and seipin, have both been implicated in controlling the metabolism and/or distribution of non-bilayer lipids. We summarize and integrate these recent advances and propose that non-bilayer lipids may play a critical role in each step of LD biogenesis.
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Xin Y, Shen C, She Y, Chen H, Wang C, Wei L, Yoon K, Han D, Hu Q, Xu J. Biosynthesis of Triacylglycerol Molecules with a Tailored PUFA Profile in Industrial Microalgae. MOLECULAR PLANT 2019; 12:474-488. [PMID: 30580039 DOI: 10.1016/j.molp.2018.12.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/29/2018] [Accepted: 12/13/2018] [Indexed: 05/06/2023]
Abstract
The composition of polyunsaturated fatty acids (PUFAs) in triacylglycerols (TAGs) is key to health benefits and for oil applications, yet the underlying genetic mechanism remains poorly understood. In this study, by in silico, ex vivo, and in vivo profiling of type-2 diacylglycerol acyltransferases (DGAT2s) in Nannochloropsis oceanica we revealed two novel PUFA-preferring enzymes that discriminate individual PUFA species in TAG assembly, with NoDGAT2J for linoleic acid (LA) and NoDGAT2K for eicosapentaenoic acid (EPA). The LA and EPA composition of TAG molecules is mediated in vivo via the functional partitioning between NoDGAT2J and 2K, both of which are localized in the chloroplast envelope. By modulating transcript abundance of the DGAT2s, an N. oceanica strain bank was created, where proportions of LA and EPA in TAG vary by 18.7-fold (between 0.21% and 3.92% dry weight) and 34.7-fold (between 0.09% and 3.12% dry weight), respectively. These findings lay the foundation for producing designer TAG molecules with tailored health benefits or for biofuel applications in industrial microalgae and higher-plant crops.
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Affiliation(s)
- Yi Xin
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chen Shen
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiting She
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong Chen
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Cong Wang
- Core Laboratory, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kangsup Yoon
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Danxiang Han
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Qiang Hu
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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48
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Sun XM, Ren LJ, Zhao QY, Ji XJ, Huang H. Enhancement of lipid accumulation in microalgae by metabolic engineering. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:552-566. [DOI: 10.1016/j.bbalip.2018.10.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/30/2018] [Accepted: 10/05/2018] [Indexed: 01/08/2023]
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Hariri H, Speer N, Bowerman J, Rogers S, Fu G, Reetz E, Datta S, Feathers JR, Ugrankar R, Nicastro D, Henne WM. Mdm1 maintains endoplasmic reticulum homeostasis by spatially regulating lipid droplet biogenesis. J Cell Biol 2019; 218:1319-1334. [PMID: 30808705 PMCID: PMC6446837 DOI: 10.1083/jcb.201808119] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 01/10/2019] [Accepted: 01/22/2019] [Indexed: 12/13/2022] Open
Abstract
Excess fatty acids are toxic to cells but can be sequestered as triacylglycerides in lipid droplets. Hariri et al. show that the tethering protein Mdm1 spatially regulates this process at the junction between the endoplasmic reticulum and the yeast vacuole. These findings suggest that Mdm1 can drive spatially defined lipid droplet production to maintain cell homeostasis and protect against lipotoxicity. Lipid droplets (LDs) serve as cytoplasmic reservoirs for energy-rich fatty acids (FAs) stored in the form of triacylglycerides (TAGs). During nutrient stress, yeast LDs cluster adjacent to the vacuole/lysosome, but how this LD accumulation is coordinated remains poorly understood. The ER protein Mdm1 is a molecular tether that plays a role in clustering LDs during nutrient depletion, but its mechanism of function remains unknown. Here, we show that Mdm1 associates with LDs through its hydrophobic N-terminal region, which is sufficient to demarcate sites for LD budding. Mdm1 binds FAs via its Phox-associated domain and coenriches with fatty acyl–coenzyme A ligase Faa1 at LD bud sites. Consistent with this, loss of MDM1 perturbs free FA activation and Dga1-dependent synthesis of TAGs, elevating the cellular FA level, which perturbs ER morphology and sensitizes yeast to FA-induced lipotoxicity. We propose that Mdm1 coordinates FA activation adjacent to the vacuole to promote LD production in response to stress, thus maintaining ER homeostasis.
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Affiliation(s)
- Hanaa Hariri
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Natalie Speer
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jade Bowerman
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Sean Rogers
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Gang Fu
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Evan Reetz
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Sanchari Datta
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - J Ryan Feathers
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Rupali Ugrankar
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Daniela Nicastro
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - W Mike Henne
- Department of Cell Biology and Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
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50
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Khan K, Kumar V, Niranjan A, Shanware A, Sane VA. JcMYB1, a Jatropha R2R3MYB Transcription Factor Gene, Modulates Lipid Biosynthesis in Transgenic Plants. PLANT & CELL PHYSIOLOGY 2019; 60:462-475. [PMID: 30476253 DOI: 10.1093/pcp/pcy223] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 11/17/2018] [Indexed: 05/11/2023]
Abstract
The lipid biosynthesis pathway in plants has been studied in detail; however, the factors that regulate the pathway at the transcription level are largely unknown. LEAFY COTYLEDON1 (LEC1), WRINKLED1 (WRI1) and FUSCA3 (FUS3) are considered master regulators to control seed oil content in Arabidopsis. Beside these master regulators, several other transcription factors that may regulate the pathway in plants are poorly studied. In the present work, we have shown the involvement of an uncharacterized Jatropha curcas R2R3MYB gene (JcMYB1) in seed oil biosynthesis. Seed oil analysis and expression profiling of fatty acid (FA) and triacylglycerol (TAG) biosynthetic genes in transgenic Arabidopsis and tobacco plants revealed that JcMYB1 enhances seed oil accumulation and alters FA composition by regulating the expression of endogenous pathway genes in transgenics. Using virus-induced gene silencing (VIGS) in Jatropha, we demonstrated that the suppression of JcMYB1 reduced lipid content with altered FA composition. Agro-infiltration and yeast one-hybrid assay results showed that JcMYB1 protein directly binds to the diacylglycerol acyltransferase1 (DGAT1) promoter, a rate-limiting enzyme of TAG biosynthesis, and activates its expression. These results suggested that JcMYB1 may augment the lipid content by regulating lipid biosynthetic genes. Additionally, manipulation of JcMYB1 in oil crop plants may be used for the potential improvement of oil production and quality.
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Affiliation(s)
- Kasim Khan
- Plant Gene Expression Lab, CSIR-National Botanical Research Institute, Lucknow, India
| | - Vinod Kumar
- Plant Gene Expression Lab, CSIR-National Botanical Research Institute, Lucknow, India
| | - Abhishek Niranjan
- Plant Gene Expression Lab, CSIR-National Botanical Research Institute, Lucknow, India
| | - Aarti Shanware
- Rajiv Gandhi Biotechnology Centre, R.T.M.N.U., Nagpur, India
| | - Vidhu A Sane
- Plant Gene Expression Lab, CSIR-National Botanical Research Institute, Lucknow, India
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