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Laframboise SJ, Deneault LF, Denoncourt A, Downey M, Baetz K. Uncovering the Role of the Yeast Lysine Acetyltransferase NuA4 in the Regulation of Nuclear Shape and Lipid Metabolism. Mol Cell Biol 2024; 44:273-288. [PMID: 38961766 PMCID: PMC11253884 DOI: 10.1080/10985549.2024.2366206] [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: 10/16/2023] [Accepted: 05/19/2024] [Indexed: 07/05/2024] Open
Abstract
Here, we report a novel role for the yeast lysine acetyltransferase NuA4 in regulating phospholipid availability for organelle morphology. Disruption of the NuA4 complex results in 70% of cells displaying nuclear deformations and nearly 50% of cells exhibiting vacuolar fragmentation. Cells deficient in NuA4 also show severe defects in the formation of nuclear-vacuole junctions (NJV), as well as a decrease in piecemeal microautophagy of the nucleus (PMN). To determine the cause of these defects we focused on Pah1, an enzyme that converts phosphatidic acid into diacylglycerol, favoring accumulation of lipid droplets over phospholipids that are used for membrane expansion. NuA4 subunit Eaf1 was required for Pah1 localization to the inner nuclear membrane and artificially tethering of Pah1 to the nuclear membrane rescued nuclear deformation and vacuole fragmentation defects, but not defects related to the formation of NVJs. Mutation of a NuA4-dependent acetylation site on Pah1 also resulted in aberrant Pah1 localization and defects in nuclear morphology and NVJ. Our work suggests a critical role for NuA4 in organelle morphology that is partially mediated through the regulation of Pah1 subcellular localization.
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Affiliation(s)
- Sarah Jane Laframboise
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
| | - Lauren F. Deneault
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
| | - Alix Denoncourt
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Michael Downey
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Kristin Baetz
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary, Alberta, Canada
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2
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Mondal S, Ghosh S. Liposome-Mediated Anti-Viral Drug Delivery Across Blood-Brain Barrier: Can Lipid Droplet Target Be Game Changers? Cell Mol Neurobiol 2023; 44:9. [PMID: 38123863 DOI: 10.1007/s10571-023-01443-4] [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: 07/18/2023] [Accepted: 12/02/2023] [Indexed: 12/23/2023]
Abstract
Lipid droplets (LDs) are subcellular organelles secreted from the endoplasmic reticulum (ER) that play a major role in lipid homeostasis. Recent research elucidates additional roles of LDs in cellular bioenergetics and innate immunity. LDs activate signaling cascades for interferon response and secretion of pro-inflammatory cytokines. Since balanced lipid homeostasis is critical for neuronal health, LDs play a crucial role in neurodegenerative diseases. RNA viruses enhance the secretion of LDs to support various phases of their life cycle in neurons which further leads to neurodegeneration. Targeting the excess LD formation in the brain could give us a new arsenal of antiviral therapeutics against neuroviruses. Liposomes are a suitable drug delivery system that could be used for drug delivery in the brain by crossing the Blood-Brain Barrier. Utilizing this, various pharmacological inhibitors and non-coding RNAs can be delivered that could inhibit the biogenesis of LDs or reduce their sizes, reversing the excess lipid-related imbalance in neurons. Liposome-Mediated Antiviral Drug Delivery Across Blood-Brain Barrier. Developing effective antiviral drug is challenging and it doubles against neuroviruses that needs delivery across the Blood-Brain Barrier (BBB). Lipid Droplets (LDs) are interesting targets for developing antivirals, hence targeting LD formation by drugs delivered using Liposomes can be game changers.
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Affiliation(s)
- Sourav Mondal
- CSIR-Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Jadavpur, Kolkata, West Bengal, 700032, India
| | - Sourish Ghosh
- CSIR-Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Jadavpur, Kolkata, West Bengal, 700032, India.
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3
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Chen D, Cai X, Xing J, Chen S, Zhao J, Qu Z, Li G, Liu H, Zheng L, Huang J, Chen XL. A lipid droplet-associated protein Nem1 regulates appressorium function for infection of Magnaporthe oryzae. ABIOTECH 2023; 4:108-123. [PMID: 37581021 PMCID: PMC10423190 DOI: 10.1007/s42994-023-00098-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 02/01/2023] [Indexed: 08/16/2023]
Abstract
Lipid droplets are important storages in fungal conidia and can be used by plant pathogenic fungi for infection. However, the regulatory mechanism of lipid droplets formation and the utilization during fungal development and infection are largely unknown. Here, in Magnaporthe oryzae, we identified a lipid droplet-associated protein Nem1 that played a key role in lipid droplets biogenesis and utilization. Nem1 was highly expressed in conidia, but lowly expressed in appressoria, and its encoded protein was localized to lipid droplets. Deletion of NEM1 resulted in reduced numbers of lipid droplets and decreased content of diacylglycerol (DAG) or triacylglycerol (TAG). NEM1 was required for asexual development especially conidia production. The Δnem1 mutant was nearly loss of virulence to host plants due to defects in appressorial penetration and invasive growth. Remarkably, Nem1 was regulated by the TOR signaling pathway and involved in the autophagy process. The Ser303 residue of Nem1 could be phosphorylated by the cAMP-PKA signaling pathway and was important for biological function of Nem1. Together, our study revealed a regulatory mechanism of lipid biogenesis and metabolism during the conidium and appressorium formation of the rice blast fungus. Supplementary Information The online version contains supplementary material available at 10.1007/s42994-023-00098-5.
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Affiliation(s)
- Deng Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Xuan Cai
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Junjie Xing
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125 China
| | - Shen Chen
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640 China
| | - Juan Zhao
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Zhiguang Qu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Guotian Li
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Hao Liu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Lu Zheng
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Junbin Huang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
| | - Xiao-Lin Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070 China
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4
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Nawade B, Kumar A, Maurya R, Subramani R, Yadav R, Singh K, Rangan P. Longer Duration of Active Oil Biosynthesis during Seed Development Is Crucial for High Oil Yield-Lessons from Genome-Wide In Silico Mining and RNA-Seq Validation in Sesame. PLANTS (BASEL, SWITZERLAND) 2022; 11:2980. [PMID: 36365434 PMCID: PMC9657858 DOI: 10.3390/plants11212980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Sesame, one of the ancient oil crops, is an important oilseed due to its nutritionally rich seeds with high protein content. Genomic scale information for sesame has become available in the public databases in recent years. The genes and their families involved in oil biosynthesis in sesame are less studied than in other oilseed crops. Therefore, we retrieved a total of 69 genes and their translated amino acid sequences, associated with gene families linked to the oil biosynthetic pathway. Genome-wide in silico mining helped identify key regulatory genes for oil biosynthesis, though the findings require functional validation. Comparing sequences of the SiSAD (stearoyl-acyl carrier protein (ACP)-desaturase) coding genes with known SADs helped identify two SiSAD family members that may be palmitoyl-ACP-specific. Based on homology with lysophosphatidic acid acyltransferase (LPAAT) sequences, an uncharacterized gene has been identified as SiLPAAT1. Identified key regulatory genes associated with high oil content were also validated using publicly available transcriptome datasets of genotypes contrasting for oil content at different developmental stages. Our study provides evidence that a longer duration of active oil biosynthesis is crucial for high oil accumulation during seed development. This underscores the importance of early onset of oil biosynthesis in developing seeds. Up-regulating, identified key regulatory genes of oil biosynthesis during early onset of seed development, should help increase oil yields.
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Affiliation(s)
- Bhagwat Nawade
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi 110012, India
| | - Ajay Kumar
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi 110012, India
| | - Rasna Maurya
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi 110012, India
| | - Rajkumar Subramani
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi 110012, India
| | - Rashmi Yadav
- Division of Germplasm Evaluation, ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi 110012, India
| | - Kuldeep Singh
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi 110012, India
| | - Parimalan Rangan
- Division of Genomic Resources, ICAR-National Bureau of Plant Genetic Resources, PUSA Campus, New Delhi 110012, India
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072, Australia
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5
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Zhao J, Sun P, Sun Q, Li R, Qin Z, Sha G, Zhou Y, Bi R, Zhang H, Zheng L, Chen X, Yang L, Li Q, Li G. The MoPah1 phosphatidate phosphatase is involved in lipid metabolism, development, and pathogenesis in Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2022; 23:720-732. [PMID: 35191164 PMCID: PMC8995063 DOI: 10.1111/mpp.13193] [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: 11/04/2021] [Revised: 01/24/2022] [Accepted: 01/26/2022] [Indexed: 05/23/2023]
Abstract
As with the majority of the hemibiotrophic fungal pathogens, the rice blast fungus Magnaporthe oryzae uses highly specialized infection structures called appressoria for plant penetration. Appressoria differentiated from germ tubes rely on enormous turgor pressure to directly penetrate the plant cell, in which process lipid metabolism plays a critical role. In this study, we characterized the MoPAH1 gene in M. oryzae, encoding a putative highly conserved phosphatidate phosphatase. The expression of MoPAH1 was up-regulated during plant infection. The MoPah1 protein is expressed at all developmental and infection stages, and is localized to the cytoplasm. Disruption of MoPAH1 causes pleiotropic defects in vegetative growth, sporulation, and heat tolerance. The lipid profile is significantly altered in the Mopah1 mutant. Lipidomics assays showed that the level of phosphatidic acid (PA) was increased in the mutant, which had reduced levels of diacylglycerol and triacylglycerol. Using a PA biosensor, we showed that the increased level of PA in the Mopah1 mutant was primarily accumulated in the vacuole. The Mopah1 mutant was blocked in both conidiation and the formation of appressorium-like structures at hyphal tips. It was nonpathogenic and failed to cause any blast lesions on rice and barley seedlings. RNA sequencing analysis revealed that MoPah1 regulates the expression of transcription factors critical for various developmental and infection-related processes. The Mopah1 mutant was reduced in the expression and phosphorylation of Pmk1 MAP kinase and delayed in autophagy. Our study demonstrates that MoPah1 is necessary for lipid metabolism, fungal development, and pathogenicity in M. oryzae.
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Affiliation(s)
- Juan Zhao
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Peng Sun
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Qiping Sun
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Renjian Li
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Ziting Qin
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Gan Sha
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Yaru Zhou
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Ruiqing Bi
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Haifeng Zhang
- Department of Plant PathologyKey Laboratory of Integrated Management of Crop Diseases and PestsMinistry of EducationCollege of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Lu Zheng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Xiao‐Lin Chen
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Long Yang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
| | - Qiang Li
- National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanChina
| | - Guotian Li
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, The Provincial Key Laboratory of Plant Pathology of Hubei ProvinceHuazhong Agricultural UniversityWuhanChina
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6
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Papagiannidis D, Bircham PW, Lüchtenborg C, Pajonk O, Ruffini G, Brügger B, Schuck S. Ice2 promotes ER membrane biogenesis in yeast by inhibiting the conserved lipin phosphatase complex. EMBO J 2021; 40:e107958. [PMID: 34617598 PMCID: PMC8591542 DOI: 10.15252/embj.2021107958] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 11/30/2022] Open
Abstract
Cells dynamically adapt organelle size to current physiological demand. Organelle growth requires membrane biogenesis and therefore needs to be coordinated with lipid metabolism. The endoplasmic reticulum (ER) can undergo massive expansion, but the underlying regulatory mechanisms are largely unclear. Here, we describe a genetic screen for factors involved in ER membrane expansion in budding yeast and identify the ER transmembrane protein Ice2 as a strong hit. We show that Ice2 promotes ER membrane biogenesis by opposing the phosphatidic acid phosphatase Pah1, called lipin in metazoa. Specifically, Ice2 inhibits the conserved Nem1‐Spo7 complex and thus suppresses the dephosphorylation and activation of Pah1. Furthermore, Ice2 cooperates with the transcriptional regulation of lipid synthesis genes and helps to maintain cell homeostasis during ER stress. These findings establish the control of the lipin phosphatase complex as an important mechanism for regulating ER membrane biogenesis.
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Affiliation(s)
- Dimitrios Papagiannidis
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany.,Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Peter W Bircham
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany
| | | | - Oliver Pajonk
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany.,Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Giulia Ruffini
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany.,Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Sebastian Schuck
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and Cell Networks Cluster of Excellence, Heidelberg, Germany.,Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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7
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Lehmann M. Diverse roles of phosphatidate phosphatases in insect development and metabolism. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2021; 133:103469. [PMID: 32931938 PMCID: PMC7952469 DOI: 10.1016/j.ibmb.2020.103469] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/10/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
The conversion of the glycerophospholipid phosphatidic acid (PA) into diacylglycerol (DAG) is essential for the biosynthesis of membrane phospholipids and storage fats. Importantly, both PA and DAG can also serve signaling functions in the cell. The dephosphorylation of PA that yields DAG can be executed by two different classes of enzymes, Mg2+-dependent lipins and Mg2+-independent lipid phosphate phosphatases. Here, I will discuss the current status of research directed at understanding the roles of these enzymes in insect development and metabolism. Special emphasis will be given to studies in the model organism Drosophila melanogaster.
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Affiliation(s)
- Michael Lehmann
- Department of Biological Sciences, SCEN 601, 1 University of Arkansas, Fayetteville, AR, 72701, USA.
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8
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Kar UP, Dey H, Rahaman A. Cardiolipin targets a dynamin-related protein to the nuclear membrane. eLife 2021; 10:64416. [PMID: 33661098 PMCID: PMC7946437 DOI: 10.7554/elife.64416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/03/2021] [Indexed: 12/03/2022] Open
Abstract
Dynamins are targeted to specific cellular membranes that they remodel via membrane fusion or fission. The molecular basis of conferring specificity to dynamins for their target membrane selection is not known. Here, we report a mechanism of nuclear membrane recruitment of Drp6, a dynamin member in Tetrahymena thermophila. Recruitment of Drp6 depends on a domain that binds to cardiolipin (CL)-rich bilayers. Consistent with this, nuclear localization of Drp6 was inhibited either by depleting cellular CL or by substituting a single amino acid residue that abolished Drp6 interactions with CL. Inhibition of CL synthesis, or perturbation in Drp6 recruitment to nuclear membrane, caused defects in the formation of new macronuclei post-conjugation. Taken together, our results elucidate a molecular basis of target membrane selection by a nuclear dynamin and establish the importance of a defined membrane-binding domain and its target lipid in facilitating nuclear expansion.
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Affiliation(s)
- Usha Pallabi Kar
- School of Biological Sciences, National Institute of Science Education and Research-HBNI, Bhubaneswar, India
| | - Himani Dey
- School of Biological Sciences, National Institute of Science Education and Research-HBNI, Bhubaneswar, India
| | - Abdur Rahaman
- School of Biological Sciences, National Institute of Science Education and Research-HBNI, Bhubaneswar, India
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9
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Hood SE, Kofler XV, Chen Q, Scott J, Ortega J, Lehmann M. Nuclear translocation ability of Lipin differentially affects gene expression and survival in fed and fasting Drosophila. J Lipid Res 2020; 61:1720-1732. [PMID: 32989002 PMCID: PMC7707171 DOI: 10.1194/jlr.ra120001051] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipins are eukaryotic proteins with functions in lipid synthesis and the homeostatic control of energy balance. They execute these functions by acting as phosphatidate phosphatase enzymes in the cytoplasm and by changing gene expression after translocation into the cell nucleus, in particular under fasting conditions. Here, we asked whether nuclear translocation and the enzymatic activity of Drosophila Lipin serve essential functions and how gene expression changes, under both fed and fasting conditions, when nuclear translocation is impaired. To address these questions, we created a Lipin null mutant, a mutant expressing Lipin lacking a nuclear localization signal (LipinΔNLS ), and a mutant expressing enzymatically dead Lipin. Our data support the conclusion that the enzymatic but not nuclear gene regulatory activity of Lipin is essential for survival. Notably, adult LipinΔNLS flies were not only viable but also exhibited improved life expectancy. In contrast, they were highly susceptible to starvation. Both the improved life expectancy in the fed state and the decreased survival in the fasting state correlated with changes in metabolic gene expression. Moreover, increased life expectancy of fed flies was associated with a decreased metabolic rate. Interestingly, in addition to metabolic genes, genes involved in feeding behavior and the immune response were misregulated in LipinΔNLS flies. Altogether, our data suggest that the nuclear activity of Lipin influences the genomic response to nutrient availability with effects on life expectancy and starvation resistance. Thus, nutritional or therapeutic approaches that aim at lowering nuclear translocation of lipins in humans may be worth exploring.
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Affiliation(s)
- Stephanie E Hood
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA
| | - Xeniya V Kofler
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA
| | - Quiyu Chen
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA
| | - Judah Scott
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA
| | - Jason Ortega
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA
| | - Michael Lehmann
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA.
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10
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Crystal structure of a lipin/Pah phosphatidic acid phosphatase. Nat Commun 2020; 11:1309. [PMID: 32161260 PMCID: PMC7066176 DOI: 10.1038/s41467-020-15124-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Lipin/Pah phosphatidic acid phosphatases (PAPs) generate diacylglycerol to regulate triglyceride synthesis and cellular signaling. Inactivating mutations cause rhabdomyolysis, autoinflammatory disease, and aberrant fat storage. Disease-mutations cluster within the conserved N-Lip and C-Lip regions that are separated by 500-residues in humans. To understand how the N-Lip and C-Lip combine for PAP function, we determined crystal structures of Tetrahymena thermophila Pah2 (Tt Pah2) that directly fuses the N-Lip and C-Lip. Tt Pah2 adopts a two-domain architecture where the N-Lip combines with part of the C-Lip to form an immunoglobulin-like domain and the remaining C-Lip forms a HAD-like catalytic domain. An N-Lip C-Lip fusion of mouse lipin-2 is catalytically active, which suggests mammalian lipins function with the same domain architecture as Tt Pah2. HDX-MS identifies an N-terminal amphipathic helix essential for membrane association. Disease-mutations disrupt catalysis or destabilize the protein fold. This illustrates mechanisms for lipin/Pah PAP function, membrane association, and lipin-related pathologies. Lipin/Pah phosphatidic acid phosphatases generate diacylglycerol to regulate triglyceride synthesis and cellular signaling. Here authors determine structures of Tetrahymena thermophila Pah2 and identify an N-terminal amphipathic helix essential for membrane association.
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11
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Garapati HS, Mishra K. Comparative genomics of nuclear envelope proteins. BMC Genomics 2018; 19:823. [PMID: 30445911 PMCID: PMC6240307 DOI: 10.1186/s12864-018-5218-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 10/31/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The nuclear envelope (NE) that encapsulates the nuclear genome is a double lipid bilayer with several integral and peripherally associated proteins. It is a characteristic feature of the eukaryotes and acts as a hub for a number of important nuclear events including transcription, repair, and regulated gene expression. The proteins associated with the nuclear envelope mediate the NE functions and maintain its structural integrity, which is crucial for survival. In spite of the importance of this structure, knowledge of the protein composition of the nuclear envelope and their function, are limited to very few organisms belonging to Opisthokonta and Archaeplastida supergroups. The NE composition is largely unknown in organisms outside these two supergroups. RESULTS In this study, we have taken a comparative sequence analysis approach to identify the NE proteome that is present across all five eukaryotic supergroups. We identified 22 proteins involved in various nuclear functions to be part of the core NE proteome. The presence of these proteins across eukaryotes, suggests that they are traceable to the Last Eukaryotic Common Ancestor (LECA). Additionally, we also identified the NE proteins that have evolved in a lineage specific manner and those that have been preserved only in a subset of organisms. CONCLUSIONS Our study identifies the conserved features of the nuclear envelope across eukaryotes and provides insights into the potential composition and the functionalities that were constituents of the LECA NE.
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Affiliation(s)
- Hita Sony Garapati
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Krishnaveni Mishra
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India.
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12
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Pichler H, Emmerstorfer-Augustin A. Modification of membrane lipid compositions in single-celled organisms – From basics to applications. Methods 2018; 147:50-65. [DOI: 10.1016/j.ymeth.2018.06.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/18/2018] [Accepted: 06/16/2018] [Indexed: 12/12/2022] Open
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13
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Shukla S, Pillai AN, Rahaman A. A putative NEM1 homologue regulates lipid droplet biogenesis via PAH1 in Tetrahymena thermophila. J Biosci 2018; 43:693-706. [PMID: 30207315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Nuclear envelope morphology protein 1 (NEM1) along with a phosphatidate phosphatase (PAH1) regulates lipid homeostasis and membrane biogenesis in yeast and mammals. We investigated four putative NEM1 homologues (TtNEM1A, TtNEM1B, TtNEM1C and TtNEM1D) in the Tetrahymena thermophila genome. Disruption of TtNEM1B, TtNEM1C or TtNEM1D did not compromise normal cell growth. In contrast, we were unable to generate knockout strain of TtNEM1A under the same conditions, indicating that TtNEM1A is essential for Tetrahymena growth. Interestingly, loss of TtNEM1B but not TtNEM1C or TtNEM1D caused a reduction in lipid droplet number. Similar to yeast and mammals, TtNem1B of Tetrahymena exerts its function via Pah1, since we found that PAH1 overexpression rescued loss of Nem1 function. However, unlike NEM1 in other organisms, TtNEM1B does not regulate ER/nuclear morphology. Similarly, neither TtNEM1C nor TtNEM1D is required to maintain normal ER morphology. While Tetrahymena PAH1 was shown to functionally replace yeast PAH1 earlier, we observed that Tetrahymena NEM1 homologues did not functionally replace yeast NEM1. Overall, our results suggest the presence of a conserved cascade for regulation of lipid homeostasis and membrane biogenesis in Tetrahymena. Our results also suggest a Nem1-independent function of Pah1 in the regulation of ER morphology in Tetrahymena.
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Affiliation(s)
- Sushmita Shukla
- National Institute of Science Education and Research (NISER), Bhubaneswar, HBNI, P.O. Jatni, Khurda, Odisha 752 050, India
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A putative NEM1 homologue regulates lipid droplet biogenesis via PAH1 in Tetrahymena thermophila. J Biosci 2018. [DOI: 10.1007/s12038-018-9794-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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