1
|
Osawa T, Fujikawa K, Shimamoto K. Structures, functions, and syntheses of glycero-glycophospholipids. Front Chem 2024; 12:1353688. [PMID: 38389730 PMCID: PMC10881803 DOI: 10.3389/fchem.2024.1353688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 01/24/2024] [Indexed: 02/24/2024] Open
Abstract
Biological membranes consist of integral and peripheral protein-associated lipid bilayers. Although constituent lipids vary among cells, membrane lipids are mainly classified as phospholipids, glycolipids, and sterols. Phospholipids are further divided into glycerophospholipids and sphingophospholipids, whereas glycolipids are further classified as glyceroglycolipids and sphingoglycolipids. Both glycerophospholipids and glyceroglycolipids contain diacylglycerol as the common backbone, but their head groups differ. Most glycerolipids have polar head groups containing phosphate esters or sugar moieties. However, trace components termed glycero-glycophospholipids, each possessing both a phosphate ester and a sugar moiety, exist in membranes. Recently, the unique biological activities of glycero-glycophospholipids have attracted considerable attention. In this review, we describe the structure, distribution, function, biosynthesis, and chemical synthetic approaches of representative glycero-glycophospholipids-phosphatidylglucoside (PtdGlc) and enterobacterial common antigen (ECA). In addition, we introduce our recent studies on the rare glycero-glyco"pyrophospho"lipid, membrane protein integrase (MPIase), which is involved in protein translocation across biomembranes.
Collapse
Affiliation(s)
- Tsukiho Osawa
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Kohki Fujikawa
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Keiko Shimamoto
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
- Department of Chemistry, Graduate School of Science, Osaka University, Osaka, Japan
| |
Collapse
|
2
|
Swain J, Bierre M, Veyrié L, Richard CA, Eleouet JF, Muriaux D, Bajorek M. Selective targeting and clustering of phosphatidylserine lipids by RSV M protein is critical for virus particle production. J Biol Chem 2023; 299:105323. [PMID: 37805138 PMCID: PMC10641529 DOI: 10.1016/j.jbc.2023.105323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 09/16/2023] [Accepted: 09/23/2023] [Indexed: 10/09/2023] Open
Abstract
Human respiratory syncytial virus (RSV) is the leading cause of infantile bronchiolitis in the developed world and of childhood deaths in resource-poor settings. The elderly and the immunosuppressed are also affected. It is a major unmet target for vaccines and antiviral drugs. RSV assembles and buds from the host cell plasma membrane by forming infectious viral particles which are mostly filamentous. A key interaction during RSV assembly is the interaction of the matrix (M) protein with cell plasma membrane lipids forming a layer at assembly sites. Although the structure of RSV M protein dimer is known, it is unclear how the viral M proteins interact with cell membrane lipids, and with which one, to promote viral assembly. Here, we demonstrate that M proteins are able to cluster at the plasma membrane by selectively binding with phosphatidylserine (PS). Our in vitro studies suggest that M binds PS lipid as a dimer and upon M oligomerization, PS clustering is observed. In contrast, the presence of other negatively charged lipids like PI(4, 5)P2 does not enhance M binding beyond control zwitterionic lipids, while cholesterol negatively affects M interaction with membrane lipids. Moreover, we show that the initial binding of the RSV M protein with PS lipids is independent of the cytoplasmic tail of the fusion (F) glycoprotein (FCT). Here, we highlight that M binding on membranes occurs directly through PS lipids, this interaction is electrostatic in nature, and M oligomerization generates PS clusters.
Collapse
Affiliation(s)
- Jitendriya Swain
- Virology and Molecular Immunology Unit (VIM), Animal Health Department, INRAE, IRIM, Montpellier, France
| | - Maxime Bierre
- INRAE, UVSQ, VIM, Université Paris-Saclay, Jouy-en-Josas, France
| | - Laura Veyrié
- Virology and Molecular Immunology Unit (VIM), Animal Health Department, INRAE, IRIM, Montpellier, France
| | | | | | - Delphine Muriaux
- Virology and Molecular Immunology Unit (VIM), Animal Health Department, INRAE, IRIM, Montpellier, France.
| | - Monika Bajorek
- INRAE, UVSQ, VIM, Université Paris-Saclay, Jouy-en-Josas, France.
| |
Collapse
|
3
|
Zhou Y, Syed JH, Semchonok DA, Wright E, Kyrilis FL, Hamdi F, Kastritis PL, Bruce BD, Reynolds TB. Solubilization, purification, and characterization of the hexameric form of phosphatidylserine synthase from Candida albicans. J Biol Chem 2023:104756. [PMID: 37116705 DOI: 10.1016/j.jbc.2023.104756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 04/30/2023] Open
Abstract
Phosphatidylserine (PS) synthase from Candida albicans, encoded by the CHO1 gene, has been identified as a potential drug target for new antifungals against systemic candidiasis. Rational drug design or small molecule screening are effective ways to identify specific inhibitors of Cho1, but both will be facilitated by protein purification. Due to the transmembrane nature of Cho1, methods were needed to solubilize and purify the native form of Cho1. Here, we used six non-ionic detergents and three styrene maleic acids (SMAs) to solubilize an HA-tagged Cho1 protein from the total microsomal fractions. Blue native PAGE (BN-PAGE) and immunoblot analysis revealed a single band corresponding to Cho1 in all detergent-solubilized fractions, while two bands were present in the SMA2000-solubilized fraction. Our enzymatic assay suggests that digitonin- or DDM-solubilized enzyme has the most PS synthase activity. Pull-downs of HA-tagged Cho1 in the digitonin-solubilized fraction reveal an apparent MW of Cho1 consistent with a hexamer. Furthermore, negative-staining electron microscopy analysis and AlphaFold2 structure prediction modeling suggest the hexamer is composed of a trimer of dimers. We purified Cho1 protein to near-homogeneity as a hexamer using affinity chromatography and TEV protease treatment, and optimized Cho1 enzyme activity for manganese and detergent concentrations, temperature (24°C), and pH (8.0). The purified Cho1 has a Km for its substrate CDP-diacylglycerol of 72.20 μM with a Vmax of 0.079 nmol/(μg*min) while exhibiting a sigmoidal kinetic curve for its other substrate serine, indicating cooperative binding. Purified hexameric Cho1 can potentially be used in downstream structure determination and small drug screening.
Collapse
Affiliation(s)
- Yue Zhou
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, TN, United States
| | - Jawhar H Syed
- Department of Biochemistry Cellular and Molecular Biology, University of Tennessee Knoxville, Knoxville, TN, United States
| | - Dmitry A Semchonok
- Interdisciplinary Research Center HALOmem & Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Edward Wright
- Department of Biochemistry Cellular and Molecular Biology, University of Tennessee Knoxville, Knoxville, TN, United States
| | - Fotis L Kyrilis
- Interdisciplinary Research Center HALOmem & Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Farzad Hamdi
- Interdisciplinary Research Center HALOmem & Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Panagiotis L Kastritis
- Interdisciplinary Research Center HALOmem & Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Barry D Bruce
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, TN, United States; Department of Biochemistry Cellular and Molecular Biology, University of Tennessee Knoxville, Knoxville, TN, United States
| | - Todd B Reynolds
- Department of Microbiology, University of Tennessee at Knoxville, Knoxville, TN, United States
| |
Collapse
|
4
|
Haram CS, Moitra S, Keane R, Kuhlmann FM, Frankfater C, Hsu FF, Beverley SM, Zhang K, Keyel PA. The sphingolipids ceramide and inositol phosphorylceramide protect the Leishmania major membrane from sterol-specific toxins. J Biol Chem 2023; 299:104745. [PMID: 37094699 PMCID: PMC10209034 DOI: 10.1016/j.jbc.2023.104745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 04/26/2023] Open
Abstract
The accessibility of sterols in mammalian cells to exogenous sterol-binding agents has been well-described previously, but sterol accessibility in distantly related protozoa is unclear. The human pathogen Leishmania major uses sterols and sphingolipids distinct from those used in mammals. Sterols in mammalian cells can be sheltered from sterol-binding agents by membrane components, including sphingolipids, but the surface exposure of ergosterol in Leishmania remains unknown. Here, we used flow cytometry to test the ability of the Leishmania major sphingolipids inositol phosphorylceramide (IPC), and ceramide to shelter ergosterol by preventing binding of the sterol-specific toxins streptolysin O and perfringolysin O and subsequent cytotoxicity. In contrast to mammalian systems, we found that Leishmania sphingolipids did not preclude toxin binding to sterols in the membrane. However, we show that IPC reduced cytotoxicity, and that ceramide reduced perfringolysin O-, but not streptolysin O-, mediated cytotoxicity in cells. Furthermore, we demonstrate ceramide sensing was controlled by the toxin L3 loop, and that ceramide was sufficient to protect L. major promastigotes from the anti-leishmaniasis drug amphotericin B. Based on these results, we propose a mechanism whereby pore-forming toxins engage additional lipids like ceramide to determine the optimal environment to sustain pore formation. Thus, L. major could serve as a genetically tractable protozoan model organism for understanding toxin-membrane interactions.
Collapse
Affiliation(s)
- Chaitanya S Haram
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - Samrat Moitra
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - Rilee Keane
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - F Matthew Kuhlmann
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Cheryl Frankfater
- Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Stephen M Beverley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - Peter A Keyel
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409.
| |
Collapse
|
5
|
Barredo PA, Balanay MP. Recent Advances in Molecular Dynamics Simulations of Tau Fibrils and Oligomers. Membranes (Basel) 2023; 13:277. [PMID: 36984665 PMCID: PMC10052016 DOI: 10.3390/membranes13030277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
The study of tau protein aggregation and interactions with other molecules or solvents using molecular dynamics simulations (MDs) is of interest to many researchers to propose new mechanism-based therapeutics for neurodegenerative diseases such as Alzheimer's disease, Pick's disease, chronic traumatic encephalopathy, and other tauopathies. In this review, we present recent MD simulation studies of tau oligomers and fibrils such as tau-NPK, tau-PHF, tau-K18, and tau-R3-R4 monomers and dimers. All-atom simulations by replica exchange MDs and coarse-grained MDs in lipid bilayers and in solution were used. The simulations revealed different mechanisms in the binding of tau in bilayers and in solutions, depending on the peptide size. Phosphorylation is also an important factor in MD simulations. The use of steered MDs was also included to simulate the dissociation of tau fibrils. The exponential improvement in the computing power of computers has led to an increasing number of scientists and engineers using a cost-effective, high-performance computing platform to study how the tau protein interacts and the effects of changing its structure, such as the phosphorylation of tau fibrils.
Collapse
Affiliation(s)
- Prechiel A. Barredo
- Department of Chemistry, Mindanao State University, Marawi City 9700, Philippines
| | - Mannix P. Balanay
- Department of Chemistry, Nazarbayev University, Astana 010000, Kazakhstan
| |
Collapse
|
6
|
López-Lara IM, Govorunova EG. Editorial: In celebration of women in science: Lipids, membranes, and membranous organelles. Front Mol Biosci 2023; 10:1187356. [PMID: 37122568 PMCID: PMC10133683 DOI: 10.3389/fmolb.2023.1187356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 04/04/2023] [Indexed: 05/02/2023] Open
Affiliation(s)
- Isabel M. López-Lara
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
- *Correspondence: Isabel M. López-Lara, ; Elena G. Govorunova,
| | - Elena G. Govorunova
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, United States
- *Correspondence: Isabel M. López-Lara, ; Elena G. Govorunova,
| |
Collapse
|
7
|
Yang Y, Li G, Wang Y, Sun Y, Xu C, Wei Z, Zhang S, Gao L, Liu S, Zhao J. Facile discovery of red blood cell deformation and compromised membrane/skeleton assembly in Prader-Willi syndrome. Front Med 2022; 16:946-956. [PMID: 36385596 DOI: 10.1007/s11684-022-0962-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/06/2022] [Indexed: 11/18/2022]
Abstract
Prader-Willi syndrome (PWS) is a rare congenital disease with genetic alterations in chromosome 15. Although genetic disorders and DNA methylation abnormalities involved in PWS have been investigated to a significant degree, other anomalies such as those in erythrocytes may occur and these have not been clearly elucidated. In the present study, we uncovered slight anemia in children with PWS that was associated with increased red blood cell (RBC) distribution width (RDW) and contrarily reduced hematocrit (HCT) values. Intriguingly, the increased ratio in RDW to HCT allowed sufficient differentiation between the PWS patients from the healthy controls and, importantly, with individuals exhibiting conventional obesity. Further morphologic examinations revealed a significant deformity in erythrocytes and mild hemolysis in PWS patients. Comprehensive mechanistic investigations unveiled compromised membrane skeletal assembly and membrane lipid composition, and revealed a reduced F-actin/G-actin ratio in PWS patients. We ascribed these phenotypic changes in erythrocytes to the observed genetic defects, including DNA methylation abnormalities. Our collective data allowed us to uncover RBC deformation in children with PWS, and this may constitute an auxiliary indicator of PWS in early childhood.
Collapse
Affiliation(s)
- Yashuang Yang
- Department of Endocrinology, Shandong Provincial Hospital, Shandong University, Jinan, 250021, China.,Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China.,Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, 250021, China
| | - Guimei Li
- Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China
| | - Yanzhou Wang
- Department of Pediatric Orthopedics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China
| | - Yan Sun
- Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China
| | - Chao Xu
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China.,Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, 250021, China
| | - Zhen Wei
- Medical Social Work Office, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China
| | - Shuping Zhang
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117, China.
| | - Ling Gao
- Department of Endocrinology, Shandong Provincial Hospital, Shandong University, Jinan, 250021, China.,Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China.,Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, 250021, China
| | - Sijin Liu
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250117, China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital, Shandong University, Jinan, 250021, China. .,Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, China. .,Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, 250021, China.
| |
Collapse
|
8
|
Abstract
Polar cell growth in plants requires a cell peripheral region that undergoes membrane extension and cell wall remodeling. Since the 1990s, RHO-RELATED GTPASES FROM PLANTS (ROPs) have been identified as master regulators that determine the site of cell growth. ROPs function to regulate actin and microtubule cytoskeletons, calcium gradients, and exocytosis, thus directing the delivery of materials for membrane and cell wall extension. In recent years, our understanding of the regulatory mechanisms underlying polar localization and the activation of ROPs has greatly advanced. Evidence points to the crucial roles of membrane lipids, receptor-like kinases, and cell wall components. In this review, we provide updates on the mechanisms underlying polarity control in tip-growing cells, with a focus on ROP effectors and membrane-associated signals. By integrating knowledge from pollen tubes, root hairs, and findings in bryophyte protonema cells and rhizoids, we hope to offer important insights into a common conceptual framework on polarity establishment governed by intercellular and extracellular signals.
Collapse
Affiliation(s)
- Hongxin Ou
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Peishan Yi
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, 610065, China
| |
Collapse
|
9
|
Marković V, Jaillais Y. Phosphatidylinositol 4-phosphate: a key determinant of plasma membrane identity and function in plants. New Phytol 2022; 235:867-874. [PMID: 35586972 DOI: 10.1111/nph.18258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 04/24/2022] [Indexed: 06/15/2023]
Abstract
Phosphatidylinositol 4-phosphate (PI4P) is an anionic phospholipid which has been described as a master regulator of the Golgi apparatus in eukaryotic cells. However, recent evidence suggests that PI4P mainly accumulates at the plasma membrane in all plant cells analyzed so far. In addition, many functions that are typically attributed to phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 ) in animal and yeast cells are also supported by PI4P in plants. For example, PI4P is the key anionic lipid that powers the strong electrostatic properties of the plasma membrane. Phosphatidylinositol 4-phosphate is also required for the establishment of stable membrane contacts between the endoplasmic reticulum and the plasma membrane, for exocytosis and to support signaling pathways. Thus, we propose that PI4P has a prominent role in specifying the identity of the plasma membrane and in supporting some of its key functions and should be considered a hallmark lipid of this compartment.
Collapse
Affiliation(s)
- Vedrana Marković
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, CNRS, INRAE, F-69342, Lyon, France
| | - Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes, Univ Lyon, ENS de Lyon, CNRS, INRAE, F-69342, Lyon, France
| |
Collapse
|
10
|
Lin YX, Xu HJ, Yin GK, Zhou YC, Lu XX, Xin X. Dynamic Changes in Membrane Lipid Metabolism and Antioxidant Defense During Soybean (Glycine max L. Merr.) Seed Aging. Front Plant Sci 2022; 13:908949. [PMID: 35812982 PMCID: PMC9263854 DOI: 10.3389/fpls.2022.908949] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
Seed viability depends upon the maintenance of functional lipids; however, how membrane lipid components dynamically change during the seed aging process remains obscure. Seed storage is accompanied by the oxidation of membrane lipids and loss of seed viability. Understanding membrane lipid changes and their effect on the cell membrane during seed aging can contribute to revealing the mechanism of seed longevity. In this study, the potential relationship between oxidative stress and membrane lipid metabolism was evaluated by using a non-targeted lipidomics approach during artificial aging of Glycine max L. Merr. Zhongdou No. 27 seeds. We determined changes in reactive oxygen species, malondialdehyde content, and membrane permeability and assessed antioxidant system activity. We found that decreased non-enzymatic antioxidant contents and catalase activity might lead to reactive oxygen species accumulation, resulting in higher electrolyte leakage and lipid peroxidation. The significantly decreased phospholipids and increased glycerolipids and lysophospholipids suggested that hydrolysis of phospholipids to form glycerolipids and lysophospholipids could be the primary pathway of membrane metabolism during seed aging. Moreover, the ratio of phosphatidylcholine to phosphatidylethanolamine, double bond index, and acyl chain length of phospholipids were found to jointly regulate membrane function. In addition, the observed changes in lipid metabolism suggest novel potential hallmarks of soybean seed aging, such as diacylglycerol 36:4; phosphatidylcholine 34:2, 36:2, and 36:4; and phosphatidylethanolamine 34:2. This knowledge can be of great significance for elucidating the molecular mechanism underlying seed aging and germplasm conservation.
Collapse
Affiliation(s)
- Yi-xin Lin
- National Crop Genebank, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
- College of Agriculture, Fujian Agricultural and Forestry University, Fuzhou, China
| | - Hai-jin Xu
- National Crop Genebank, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
- College of Agriculture, Fujian Agricultural and Forestry University, Fuzhou, China
| | - Guang-kun Yin
- National Crop Genebank, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuan-chang Zhou
- College of Agriculture, Fujian Agricultural and Forestry University, Fuzhou, China
| | - Xin-xiong Lu
- National Crop Genebank, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xia Xin
- National Crop Genebank, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| |
Collapse
|
11
|
Zhang X, Xie H, Iaea D, Khelashvili G, Weinstein H, Maxfield FR. Phosphatidylinositol phosphates modulate interactions between the StarD4 sterol trafficking protein and lipid membranes. J Biol Chem 2022; 298:102058. [PMID: 35605664 DOI: 10.1016/j.jbc.2022.102058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/12/2022] [Accepted: 05/18/2022] [Indexed: 11/22/2022] Open
Abstract
There is substantial evidence for extensive nonvesicular sterol transport in cells. For example, lipid transfer by the steroidogenic acute regulator-related proteins (StarD) containing a StarT domain has been shown to involve several pathways of nonvesicular trafficking. Among the soluble StarT domain–containing proteins, StarD4 is expressed in most tissues and has been shown to be an effective sterol transfer protein. However, it was unclear whether the lipid composition of donor or acceptor membranes played a role in modulating StarD4-mediated transport. Here, we used fluorescence-based assays to demonstrate a phosphatidylinositol phosphate (PIP)-selective mechanism by which StarD4 can preferentially extract sterol from liposome membranes containing certain PIPs (especially, PI(4,5)P2 and to a lesser degree PI(3,5)P2). Monophosphorylated PIPs and other anionic lipids had a smaller effect on sterol transport. This enhancement of transport was less effective when the same PIPs were present in the acceptor membranes. Furthermore, using molecular dynamics (MD) simulations, we mapped the key interaction sites of StarD4 with PIP-containing membranes and identified residues that are important for this interaction and for accelerated sterol transport activity. We show that StarD4 recognizes membrane-specific PIPs through specific interaction with the geometry of the PIP headgroup as well as the surrounding membrane environment. Finally, we also observed that StarD4 can deform membranes upon longer incubations. Taken together, these results suggest a mechanism by which PIPs modulate cholesterol transfer activity via StarD4.
Collapse
|
12
|
Ribbenstedt A, Armitage JM, Günther F, Arnot JA, Droge STJ, McLachlan MS. In Vivo Bioconcentration of 10 Anionic Surfactants in Rainbow Trout Explained by In Vitro Data on Partitioning and S9 Clearance. Environ Sci Technol 2022; 56:6305-6314. [PMID: 35467837 PMCID: PMC9118553 DOI: 10.1021/acs.est.1c05543] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Bioconcentration factors (BCFs) in rainbow trout were measured for 10 anionic surfactants with a range of alkyl chain lengths and different polar head groups. The BCFs ranged from 0.04 L kg-1 ww (for C10SO3) to 1370 L kg-1 ww (C16SO3). There was a strong correlation between the log BCF and log membrane lipid-water distribution ratio (DMLW, r2 = 0.96), and biotransformation was identified as the dominant elimination mechanism. The strong positive influence of DMLW on BCF was attributed to two phenomena: (i) increased partitioning from water into the epithelial membrane of the gill, leading to more rapid diffusion across this barrier and more rapid uptake, and (ii) increased sequestration of the surfactant body burden into membranes and other body tissues, resulting in lower freely dissolved concentrations available for biotransformation. Estimated whole-body in vivo biotransformation rate constants kB-BCF are within a factor three of rate constants estimated from S9 in vitro assays for six of the eight test chemicals for which kB-BCF could be determined. A model-based assessment indicated that the hepatic clearance rate of freely dissolved chemicals was similar for the studied surfactants. The dataset will be useful for evaluation of in silico and in vitro methods to assess bioaccumulation.
Collapse
Affiliation(s)
- Anton Ribbenstedt
- Department
of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden
| | - James M. Armitage
- AES
Armitage Environmental Sciences, Inc., Ottawa, Ontario K1L 8C3, Canada
| | - Felix Günther
- Department
of Mathematics, Stockholm University, 106 91 Stockholm, Sweden
| | - Jon A. Arnot
- ARC
Arnot Research and Consulting Inc., Toronto, Ontario M4M 1W4, Canada
- Department
of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Steven T. J. Droge
- Institute
for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1090 GE Amsterdam, The Netherlands
| | - Michael S. McLachlan
- Department
of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden
| |
Collapse
|
13
|
Yang M, Xie X, Kong FT, Xie KP, Yu SH, Ma JY, Xue S, Gong Z. Differences in Glycerolipid Response of Chlamydomonas reinhardtii Starchless Mutant to High Light and Nitrogen Deprivation Stress Under Three Carbon Supply Regimes. Front Plant Sci 2022; 13:860966. [PMID: 35599875 PMCID: PMC9120814 DOI: 10.3389/fpls.2022.860966] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/06/2022] [Indexed: 06/15/2023]
Abstract
Carbon source serves as a crucial factor for microalgal lipid biosynthesis. The supplied exogenous inorganic or organic carbon affects lipid accumulation in microalgae under stress conditions. However, the impacts of different carbon availability on glycerolipid metabolism, triacylglycerol (TAG) metabolism in particular, still remain elusive in microalgae. Chlamydomonas starchless mutant BAFJ5 has emerged as a model system to study TAG metabolism, due to its property of hyper-accumulating TAG. In this study, the glycerolipidomic response of the starchless BAFJ5 to high light and nitrogen-deprived (HL-N) stress was deciphered in detail to distinguish glycerolipid metabolism under three carbon supply regimes. The results revealed that the autotrophically and mixotrophically grown BAFJ5 cells aerated with air containing 2% CO2 presented similar changes in growth, photosynthetic activity, biochemical components, and glycerolipid metabolism under HL-N conditions. But the mixotrophically grown BAFJ5 aerated with air containing 0.04% CO2 exhibited more superior accumulation in TAG, which was esterified with a significantly higher proportion of C18:1n9 and prominently the lower proportions of polyunsaturated fatty acids. In addition, these cells increased the relative levels of C18:2n6 in the membrane lipids, i.e., monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), in priority, and decreased that of C18:3n3 and C18:4n3 in the betaine lipid, N,N,N-trimethylhomoserine diacylglycerol (DGTS), subsequently, to adapt to the HL-N stress conditions, compared to the cells under the other two conditions. Thus, it was suggested that C. reinhardtii starchless mutant appeared to present distinct metabolism for TAG biosynthesis involving membrane lipid remodeling under distinct carbon supply regimes. This study provides insights into how the different carbon supply regimes affect lipid metabolism in Chlamydomonas starchless cells, which will benefit the optimized production of storage lipids in microalgae.
Collapse
Affiliation(s)
- Miao Yang
- Key Laboratory of Plant Biotechnology of Liaoning Province, School of Life Sciences, Liaoning Normal University, Dalian, China
- Dalian Key Laboratory of Marine Bioactive Polypeptide Drugs, School of Life Sciences, Liaoning Normal University, Dalian, China
| | - Xi Xie
- Liaoning Ocean and Fisheries Science Research Institute, Dalian, China
| | - Fan-Tao Kong
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Kun-Peng Xie
- Key Laboratory of Plant Biotechnology of Liaoning Province, School of Life Sciences, Liaoning Normal University, Dalian, China
- Dalian Key Laboratory of Marine Bioactive Polypeptide Drugs, School of Life Sciences, Liaoning Normal University, Dalian, China
| | - Si-Hui Yu
- Key Laboratory of Plant Biotechnology of Liaoning Province, School of Life Sciences, Liaoning Normal University, Dalian, China
- Dalian Key Laboratory of Marine Bioactive Polypeptide Drugs, School of Life Sciences, Liaoning Normal University, Dalian, China
| | - Jing-Yi Ma
- Key Laboratory of Plant Biotechnology of Liaoning Province, School of Life Sciences, Liaoning Normal University, Dalian, China
- Dalian Key Laboratory of Marine Bioactive Polypeptide Drugs, School of Life Sciences, Liaoning Normal University, Dalian, China
| | - Song Xue
- School of Bioengineering, Dalian University of Technology, Dalian, China
| | - Zheng Gong
- Key Laboratory of Plant Biotechnology of Liaoning Province, School of Life Sciences, Liaoning Normal University, Dalian, China
- Dalian Key Laboratory of Marine Bioactive Polypeptide Drugs, School of Life Sciences, Liaoning Normal University, Dalian, China
| |
Collapse
|
14
|
Zhou Y, Cassilly CD, Reynolds TB. Mapping the Substrate-Binding Sites in the Phosphatidylserine Synthase in Candida albicans. Front Cell Infect Microbiol 2022; 11:765266. [PMID: 35004345 PMCID: PMC8727905 DOI: 10.3389/fcimb.2021.765266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/29/2021] [Indexed: 12/02/2022] Open
Abstract
The fungal phosphatidylserine (PS) synthase, a membrane protein encoded by the CHO1 gene, is a potential drug target for pathogenic fungi, such as Candida albicans. However, both substrate-binding sites of C. albicans Cho1 have not been characterized. Cho1 has two substrates: cytidyldiphosphate-diacylglycerol (CDP-DAG) and serine. Previous studies identified a conserved CDP-alcohol phosphotransferase (CAPT) binding motif, which is present within Cho1. We tested the CAPT motif for its role in PS synthesis by mutating conserved residues using alanine substitution mutagenesis. PS synthase assays revealed that mutations in all but one conserved amino acid within the CAPT motif resulted in decreased Cho1 function. In contrast, there were no clear motifs in Cho1 for binding serine. Therefore, to identify the serine binding site, PS synthase sequences from three fungi were aligned with sequences of a similar enzyme, phosphatidylinositol (PI) synthase, from the same fungi. This revealed a motif that was unique to PS synthases. Using alanine substitution mutagenesis, we found that some of the residues in this motif are required for Cho1 function. Two alanine substitution mutants, L184A and R189A, exhibited contrasting impacts on PS synthase activity, and were characterized for their Michaelis-Menten kinetics. The L184A mutant displayed enhanced PS synthase activity and showed an increased Vmax. In contrast, R189A showed decreased PS synthase activity and increased Km for serine, suggesting that residue R189 is involved in serine binding. These results help to characterize PS synthase substrate binding, and should direct rational approaches for finding Cho1 inhibitors that may lead to better antifungals.
Collapse
Affiliation(s)
- Yue Zhou
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, TN, United States
| | - Chelsi D Cassilly
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, TN, United States
| | - Todd B Reynolds
- Department of Microbiology, University of Tennessee Knoxville, Knoxville, TN, United States
| |
Collapse
|
15
|
Abstract
Phospholipids are major membrane lipids that consist of lipid bilayers. This basic cellular structure acts as a barrier to protect the cell against various environmental insults and more importantly, enables multiple cellular processes to occur in subcellular compartments. Numerous studies have linked the complexity of membrane lipids to signal transductions, organelle functions, as well as physiological processes, and human diseases. Recently, crucial roles for membrane lipids in the aging process are beginning to emerge. In this study, we summarized current advances in our understanding of the relationship between membrane lipids and aging with an emphasis on phospholipid species. We surveyed how major phospholipid species change with age in different organisms and tissues, and some common patterns of membrane lipid change during aging were proposed. Further, the functions of different phospholipid molecules in regulating healthspan and lifespan, as well as their potential mechanisms of action, were also discussed.
Collapse
Affiliation(s)
- Yucan Dai
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Haiqing Tang
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Shanshan Pang
- School of Life Sciences, Chongqing University, Chongqing, China
| |
Collapse
|
16
|
Rajagopal R, Sylvester B, Zhang S, Adak S, Wei X, Bowers M, Jessberger S, Hsu FF, Semenkovich CF. Glucose-mediated de novo lipogenesis in photoreceptors drives early diabetic retinopathy. J Biol Chem 2021; 297:101104. [PMID: 34425110 PMCID: PMC8445899 DOI: 10.1016/j.jbc.2021.101104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/10/2021] [Accepted: 08/18/2021] [Indexed: 11/23/2022] Open
Abstract
Diabetic retinopathy (DR) is an increasingly frequent cause of blindness across populations; however, the events that initiate pathophysiology of DR remain elusive. Strong preclinical and clinical evidence suggests that abnormalities in retinal lipid metabolism caused by diabetes may account for the origin of this disease. A major arm of lipid metabolism, de novo biosynthesis, is driven by elevation in available glucose, a common thread binding all forms of vision loss in diabetes. Therefore, we hypothesized that aberrant retinal lipid biogenesis is an important promoter of early DR. In murine models, we observed elevations of diabetes-associated retinal de novo lipogenesis ∼70% over control levels. This shift was primarily because of activation of fatty acid synthase (FAS), a rate-limiting enzyme in the biogenic pathway. Activation of FAS was driven by canonical glucose-mediated disinhibition of acetyl-CoA carboxylase, a major upstream regulatory enzyme. Mutant mice expressing gain-of-function FAS demonstrated increased vulnerability to DR, whereas those with FAS deletion in rod photoreceptors maintained preserved visual responses upon induction of diabetes. Excess retinal de novo lipogenesis—either because of diabetes or because of FAS gain of function—was associated with modestly increased levels of palmitate-containing phosphatidylcholine species in synaptic membranes, a finding with as yet uncertain significance. These findings implicate glucose-dependent increases in photoreceptor de novo lipogenesis in the early pathogenesis of DR, although the mechanism of deleterious action of this pathway remains unclear.
Collapse
Affiliation(s)
- Rithwick Rajagopal
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri, USA.
| | - Beau Sylvester
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Sheng Zhang
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Sangeeta Adak
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Xiaochao Wei
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Megan Bowers
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Sebastian Jessberger
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Fong-Fu Hsu
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Clay F Semenkovich
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri, USA; Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, Missouri, USA.
| |
Collapse
|
17
|
Renard K, Byrne B. Insights into the Role of Membrane Lipids in the Structure, Function and Regulation of Integral Membrane Proteins. Int J Mol Sci 2021; 22:9026. [PMID: 34445730 DOI: 10.3390/ijms22169026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/15/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023] Open
Abstract
Membrane proteins exist within the highly hydrophobic membranes surrounding cells and organelles, playing key roles in cellular function. It is becoming increasingly clear that the membrane does not just act as an appropriate environment for these proteins, but that the lipids that make up these membranes are essential for membrane protein structure and function. Recent technological advances in cryogenic electron microscopy and in advanced mass spectrometry methods, as well as the development of alternative membrane mimetic systems, have allowed experimental study of membrane protein–lipid complexes. These have been complemented by computational approaches, exploiting the ability of Molecular Dynamics simulations to allow exploration of membrane protein conformational changes in membranes with a defined lipid content. These studies have revealed the importance of lipids in stabilising the oligomeric forms of membrane proteins, mediating protein–protein interactions, maintaining a specific conformational state of a membrane protein and activity. Here we review some of the key recent advances in the field of membrane protein–lipid studies, with major emphasis on respiratory complexes, transporters, channels and G-protein coupled receptors.
Collapse
|
18
|
Pan NC, Zhang T, Hu S, Liu C, Wang Y. Fast desensitization of acetylcholine receptors induced by a spider toxin. Channels (Austin) 2021; 15:507-515. [PMID: 34374321 PMCID: PMC8366537 DOI: 10.1080/19336950.2021.1961459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) are members of the “cys-loop” ligand-gated ion channel superfamily that play important roles in both the peripheral and central system. At the neuromuscular junction, the endplate current is induced by ACh binding and nAChR activation, and then, the current declines to a small steady state, even though ACh is still bound to the receptors. The kinetics of nAChRs with high affinity for ACh but no measurable ion conductance is called desensitization. This adopted desensitization of nAChR channel currents might be an important mechanism for protecting cells against uncontrolled excitation. This study aimed to show that Grammostola spatulata toxin (GsMTx4), which was first purified and characterized from the venom of the tarantula Grammostola spatulata (now genus Phixotricus), can facilitate the desensitization of nAChRs in murine C2C12 myotubes. To examine the details, muscle-type nAChRs, which are expressed heterologously in HEK293T cells, were studied. A single channel current was recorded under the cell-attached configuration, and the channel activity (NPo) decayed much faster after the addition of GsMTx-4 to the pipette solution. The channel kinetics were further analyzed, and GsMTx-4 affected the channel activity of nAChRs by prolonging the closing time without affecting channel conductance or opening activity. The interaction between nAChRs embedded in the lipid membrane and toxin inserted into the membrane may contribute to the conformational change in the receptor and thus change the channel activity. This new property of GsMTx-4 may lead to a better understanding of the desensitization of ligand-gated channels and disease therapy.
Collapse
Affiliation(s)
- Na Clara Pan
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Tingting Zhang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Shimin Hu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Chunyan Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Centre of Epilepsy, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| |
Collapse
|
19
|
Suresh P, Miller WT, London E. Phospholipid exchange shows insulin receptor activity is supported by both the propensity to form wide bilayers and ordered raft domains. J Biol Chem 2021; 297:101010. [PMID: 34324831 PMCID: PMC8379460 DOI: 10.1016/j.jbc.2021.101010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 11/29/2022] Open
Abstract
Insulin receptor (IR) is a membrane tyrosine kinase that mediates the response of cells to insulin. IR activity has been shown to be modulated by changes in plasma membrane lipid composition, but the properties and structural determinants of lipids mediating IR activity are poorly understood. Here, using efficient methyl-alpha-cyclodextrin mediated lipid exchange, we studied the effect of altering plasma membrane outer leaflet phospholipid composition upon the activity of IR in mammalian cells. After substitution of endogenous lipids with lipids having an ability to form liquid ordered (Lo) domains (sphingomyelins) or liquid disordered (Ld) domains (unsaturated phosphatidylcholines (PCs)), we found that the propensity of lipids to form ordered domains is required for high IR activity. Additional substitution experiments using a series of saturated PCs showed that IR activity increased substantially with increasing acyl chain length, which increases both bilayer width and the propensity to form ordered domains. Incorporating purified IR into alkyl maltoside micelles with increasing hydrocarbon lengths also increased IR activity, but more modestly than by increasing lipid acyl chain length in cells. These results suggest that the ability to form Lo domains as well as wide bilayer width contributes to increased IR activity. Inhibition of phosphatases showed that some of the lipid dependence of IR activity upon lipid structure reflected protection from phosphatases by lipids that support Lo domain formation. These results are consistent with a model in which a combination of bilayer width and ordered domain formation modulates IR activity via IR conformation and accessibility to phosphatases.
Collapse
Affiliation(s)
- Pavana Suresh
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, USA
| | - W Todd Miller
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York, USA; Department of Veterans Affairs Medical Center, Northport, New York, USA
| | - Erwin London
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, USA.
| |
Collapse
|
20
|
Geiger O, Sohlenkamp C, Vera-Cruz D, Medeot DB, Martínez-Aguilar L, Sahonero-Canavesi DX, Weidner S, Pühler A, López-Lara IM. ExoS/ChvI Two-Component Signal-Transduction System Activated in the Absence of Bacterial Phosphatidylcholine. Front Plant Sci 2021; 12:678976. [PMID: 34367203 PMCID: PMC8343143 DOI: 10.3389/fpls.2021.678976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
Sinorhizobium meliloti contains the negatively charged phosphatidylglycerol and cardiolipin as well as the zwitterionic phosphatidylethanolamine (PE) and phosphatidylcholine (PC) as major membrane phospholipids. In previous studies we had isolated S. meliloti mutants that lack PE or PC. Although mutants deficient in PE are able to form nitrogen-fixing nodules on alfalfa host plants, mutants lacking PC cannot sustain development of any nodules on host roots. Transcript profiles of mutants unable to form PE or PC are distinct; they differ from each other and they are different from the wild type profile. For example, a PC-deficient mutant of S. meliloti shows an increase of transcripts that encode enzymes required for succinoglycan biosynthesis and a decrease of transcripts required for flagellum formation. Indeed, a PC-deficient mutant is unable to swim and overproduces succinoglycan. Some suppressor mutants, that regain swimming and form normal levels of succinoglycan, are altered in the ExoS sensor. Our findings suggest that the lack of PC in the sinorhizobial membrane activates the ExoS/ChvI two-component regulatory system. ExoS/ChvI constitute a molecular switch in S. meliloti for changing from a free-living to a symbiotic life style. The periplasmic repressor protein ExoR controls ExoS/ChvI function and it is thought that proteolytic ExoR degradation would relieve repression of ExoS/ChvI thereby switching on this system. However, as ExoR levels are similar in wild type, PC-deficient mutant and suppressor mutants, we propose that lack of PC in the bacterial membrane provokes directly a conformational change of the ExoS sensor and thereby activation of the ExoS/ChvI two-component system.
Collapse
Affiliation(s)
- Otto Geiger
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Christian Sohlenkamp
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Diana Vera-Cruz
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Daniela B. Medeot
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | | | | | - Stefan Weidner
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Alfred Pühler
- Institut für Genomforschung und Systembiologie, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Isabel M. López-Lara
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| |
Collapse
|
21
|
Yu L, Zhou C, Fan J, Shanklin J, Xu C. Mechanisms and functions of membrane lipid remodeling in plants. Plant J 2021; 107:37-53. [PMID: 33853198 DOI: 10.1111/tpj.15273] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 05/20/2023]
Abstract
Lipid remodeling, defined herein as post-synthetic structural modifications of membrane lipids, play crucial roles in regulating the physicochemical properties of cellular membranes and hence their many functions. Processes affected by lipid remodeling include lipid metabolism, membrane repair, cellular homeostasis, fatty acid trafficking, cellular signaling and stress tolerance. Glycerolipids are the major structural components of cellular membranes and their composition can be adjusted by modifying their head groups, their acyl chain lengths and the number and position of double bonds. This review summarizes recent advances in our understanding of mechanisms of membrane lipid remodeling with emphasis on the lipases and acyltransferases involved in the modification of phosphatidylcholine and monogalactosyldiacylglycerol, the major membrane lipids of extraplastidic and photosynthetic membranes, respectively. We also discuss the role of triacylglycerol metabolism in membrane acyl chain remodeling. Finally, we discuss emerging data concerning the functional roles of glycerolipid remodeling in plant stress responses. Illustrating the molecular basis of lipid remodeling may lead to novel strategies for crop improvement and other biotechnological applications such as bioenergy production.
Collapse
Affiliation(s)
- Linhui Yu
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Chao Zhou
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - John Shanklin
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| |
Collapse
|
22
|
Zhang L, Gui T, Console L, Scalise M, Indiveri C, Hausler S, Kullak-Ublick GA, Gai Z, Visentin M. Cholesterol stimulates the cellular uptake of L-carnitine by the carnitine/organic cation transporter novel 2 (OCTN2). J Biol Chem 2020; 296:100204. [PMID: 33334877 PMCID: PMC7948396 DOI: 10.1074/jbc.ra120.015175] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 12/14/2020] [Accepted: 12/17/2020] [Indexed: 12/19/2022] Open
Abstract
The carnitine/organic cation transporter novel 2 (OCTN2) is responsible for the cellular uptake of carnitine in most tissues. Being a transmembrane protein OCTN2 must interact with the surrounding lipid microenvironment to function. Among the main lipid species that constitute eukaryotic cells, cholesterol has highly dynamic levels under a number of physiopathological conditions. This work describes how plasma membrane cholesterol modulates OCTN2 transport of L-carnitine in human embryonic kidney 293 cells overexpressing OCTN2 (OCTN2-HEK293) and in proteoliposomes harboring human OCTN2. We manipulated the cholesterol content of intact cells, assessed by thin layer chromatography, through short exposures to empty and/or cholesterol-saturated methyl-β-cyclodextrin (mβcd), whereas free cholesterol was used to enrich reconstituted proteoliposomes. We measured OCTN2 transport using [3H]L-carnitine, and expression levels and localization by surface biotinylation and Western blotting. A 20-min preincubation with mβcd reduced the cellular cholesterol content and inhibited L-carnitine influx by 50% in comparison with controls. Analogously, the insertion of cholesterol in OCTN2-proteoliposomes stimulated L-carnitine uptake in a dose-dependent manner. Carnitine uptake in cells incubated with empty mβcd and cholesterol-saturated mβcd to preserve the cholesterol content was comparable with controls, suggesting that the mβcd effect on OCTN2 was cholesterol dependent. Cholesterol stimulated L-carnitine influx in cells by markedly increasing the affinity for L-carnitine and in proteoliposomes by significantly enhancing the affinity for Na+ and, in turn, the L-carnitine maximal transport capacity. Because of the antilipogenic and antioxidant features of L-carnitine, the stimulatory effect of cholesterol on L-carnitine uptake might represent a novel protective effect against lipid-induced toxicity and oxidative stress.
Collapse
Affiliation(s)
- Lu Zhang
- College of Traditional Chinese Medicine, Innovation Research Institute of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China; Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Ting Gui
- College of Traditional Chinese Medicine, Innovation Research Institute of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Lara Console
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Stephanie Hausler
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Gerd A Kullak-Ublick
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Mechanistic Safety, CMO & Patient Safety, Global Drug Development, Novartis Pharma, Basel, Switzerland
| | - Zhibo Gai
- College of Traditional Chinese Medicine, Innovation Research Institute of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China; Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Michele Visentin
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| |
Collapse
|
23
|
Yoshida R, Hemmi H. Construction of an artificial biosynthetic pathway for hyperextended archaeal membrane lipids in the bacterium Escherichia coli. Synth Biol (Oxf) 2020; 5:ysaa018. [PMID: 33263085 PMCID: PMC7680562 DOI: 10.1093/synbio/ysaa018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/08/2020] [Accepted: 09/16/2020] [Indexed: 11/12/2022] Open
Abstract
Archaea produce unique membrane lipids, which possess two fully saturated isoprenoid chains linked to the glycerol moiety via ether bonds. The isoprenoid chain length of archaeal membrane lipids is believed to be important for some archaea to thrive in extreme environments because the hyperthermophilic archaeon Aeropyrum pernix and some halophilic archaea synthesize extended C25,C25-archaeal diether-type membrane lipids, which have isoprenoid chains that are longer than those of typical C20,C20-diether lipids. Natural archaeal diether lipids possessing longer C30 or C35 isoprenoid chains, however, have yet to be isolated. In the present study, we attempted to synthesize such hyperextended archaeal membrane lipids. We investigated the substrate preference of the enzyme sn-2,3-(digeranylfarnesyl)glycerol-1-phosphate synthase from A. pernix, which catalyzes the transfer of the second C25 isoprenoid chain to the glycerol moiety in the biosynthetic pathway of C25,C25-archaeal membrane lipids. The enzyme was shown to accept sn-3-hexaprenylglycerol-1-phosphate, which has a C30 isoprenoid chain, as a prenyl acceptor substrate to synthesize sn-2-geranylfarnesyl-3-hexaprenylglycerol-1-phosphate, a supposed precursor for hyperextended C25,C30-archaeal membrane lipids. Furthermore, we constructed an artificial biosynthetic pathway by introducing 4 archaeal genes and 1 gene from Bacillus subtilis in the cells of Escherichia coli, which enabled the E. coli strain to produce hyperextended C25,C30-archaeal membrane lipids, which have never been reported so far.
Collapse
Affiliation(s)
- Ryo Yoshida
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 460-8601, Japan
| | - Hisashi Hemmi
- Department of Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 460-8601, Japan
| |
Collapse
|
24
|
Ali MH, Sobze JM, Pham TH, Nadeem M, Liu C, Galagedara L, Cheema M, Thomas R. Carbon Nanotubes Improved the Germination and Vigor of Plant Species from Peatland Ecosystem Via Remodeling the Membrane Lipidome. Nanomaterials (Basel) 2020; 10:nano10091852. [PMID: 32947854 PMCID: PMC7557389 DOI: 10.3390/nano10091852] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 12/03/2022]
Abstract
Application of the nanopriming technique to alleviate seed dormancy has shown promising results in various agricultural crop species. However, there is a dearth of knowledge regarding its potential use in native peatland boreal forest species to alleviate seed dormancy and improve their propagation or vigor for forest reclamation activities. Herein, we demonstrate the use of nanopriming with carbon nanotubes (CNT) to alleviate seed dormancy, improved seed germination, and seedling vigor in two boreal peatland species. Bog birch (Betula pumila L.) and Labrador tea (Rhododendron groenlandicum L.) seeds with embryo or seed coat dormancy were nanoprimed with either 20 or 40 µg/mL CNT, cold stratified at 2–4 °C for 15 days, and allowed to germinate at room temperature. The emerged seedlings’ lipidome was assessed to decipher the role of lipid metabolism in alleviating seed dormancy. We observed significant (p < 0.05) improvement in seedling germination and seedling vigor in seeds primed with multiwalled carbon nanotubes functionalized with carboxylic acids. Phosphatidylcholine (PC 18:1/18:3), phosphatidylglycerol (PG 16:1/18:3), and lysophosphatidylcholine (LPC 18:3) molecular species (C18:3 enriched) were observed to be highly correlated with the increased seed germination percentages and the enhanced seedling vigor. Mechanistically, it appears that carbon nanoprimed seeds following stratification are effective in mediating seed dormancy by remodeling the seed membrane lipids (C18:3 enriched PC, PG, and LPC) in both peatland boreal forest species. The study results demonstrate that nanopriming may provide a solution to resolve seed dormancy issues by enhancing seed germination, propagation, and seedling vigor in non-resource boreal forest species ideally suited for forest reclamation following anthropogenic disturbances.
Collapse
Affiliation(s)
- Md. Hossen Ali
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Jean-Marie Sobze
- Northern Alberta Institute of Technology, Boreal Research Institute, 8102-99 Avenue, Peace River, AB T8S 1R2, Canada;
| | - Thu Huong Pham
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Muhammad Nadeem
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
- Correspondence: (M.N.); (R.T.)
| | - Chen Liu
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Lakshman Galagedara
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Mumtaz Cheema
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Raymond Thomas
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
- Correspondence: (M.N.); (R.T.)
| |
Collapse
|
25
|
Li M, Gašparovič H, Weng X, Chen S, Korduláková J, Jessen-Trefzer C. The Two-Component Locus MSMEG_0244/0246 Together With MSMEG_0243 Affects Biofilm Assembly in M. smegmatis Correlating With Changes in Phosphatidylinositol Mannosides Acylation. Front Microbiol 2020; 11:570606. [PMID: 33013801 PMCID: PMC7516205 DOI: 10.3389/fmicb.2020.570606] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/24/2020] [Indexed: 12/30/2022] Open
Abstract
Ferric and ferrous iron is an essential transition metal for growth of many bacterial species including mycobacteria. The genomic region msmeg_0234 to msmeg_0252 from Mycobacterium smegmatis is putatively involved in iron/heme metabolism. We investigate the genes encoding the presumed two component system MSMEG_0244/MSMEG_0246, the neighboring gene msmeg_0243 and their involvement in this process. We show that purified MSMEG_0243 indeed is a heme binding protein. Deletion of msmeg_0243/msmeg_0244/msmeg_0246 in Mycobacterium smegmatis leads to a defect in biofilm formation and colony growth on solid agar, however, this phenotype is independent of the supplied iron source. Further, analysis of the corresponding mutant and its lipids reveals that changes in morphology and biofilm formation correlate with altered acylation patterns of phosphatidylinositol mannosides (PIMs). We provide the first evidence that msmeg_0244/msmeg_0246 work in concert in cellular lipid homeostasis, especially in the maintenance of PIMs, with the heme-binding protein MSMEG_0243 as potential partner.
Collapse
Affiliation(s)
- Miaomaio Li
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Henrich Gašparovič
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Xing Weng
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Si Chen
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Jana Korduláková
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Claudia Jessen-Trefzer
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| |
Collapse
|
26
|
Mirheydari M, Dey P, Stukey GJ, Park Y, Han GS, Carman GM. The Spo7 sequence LLI is required for Nem1-Spo7/Pah1 phosphatase cascade function in yeast lipid metabolism. J Biol Chem 2020; 295:11473-11485. [PMID: 32527729 DOI: 10.1074/jbc.ra120.014129] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/09/2020] [Indexed: 11/06/2022] Open
Abstract
The Nem1-Spo7 complex in the yeast Saccharomyces cerevisiae is a protein phosphatase that catalyzes the dephosphory-lation of Pah1 phosphatidate phosphatase, required for its translocation to the nuclear/endoplasmic reticulum membrane. The Nem1-Spo7/Pah1 phosphatase cascade plays a major role in triacylglycerol synthesis and in the regulation of phospholipid synthesis. In this work, we examined Spo7, a regulatory subunit required for Nem1 catalytic function, to identify residues that govern formation of the Nem1-Spo7 complex. By deletion analysis of Spo7, we identified a hydrophobic Leu-Leu-Ile (LLI) sequence comprising residues 54-56 as being required for the protein to complement the temperature-sensitive phenotype of an spo7Δ mutant strain. Mutational analysis of the LLI sequence with alanine and arginine substitutions showed that its overall hydrophobicity is crucial for the formation of the Nem1-Spo7 complex as well as for the Nem1 catalytic function on its substrate, Pah1, in vivo Consistent with the role of the Nem1-Spo7 complex in activating the function of Pah1, we found that the mutational effects of the Spo7 LLI sequence were on the Nem1-Spo7/Pah1 axis that controls lipid synthesis and related cellular processes (e.g. triacylglycerol/phospholipid synthesis, lipid droplet formation, nuclear/endoplasmic reticulum membrane morphology, vacuole fusion, and growth on glycerol medium). These findings advance the understanding of Nem1-Spo7 complex formation and its role in the phosphatase cascade that regulates the function of Pah1 phosphatidate phosphatase.
Collapse
Affiliation(s)
- Mona Mirheydari
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
| | - Prabuddha Dey
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
| | - Geordan J Stukey
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, USA
| | - Yeonhee Park
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey, 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, New Jersey, 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, New Jersey, USA
| |
Collapse
|
27
|
Murakami H, Kakutani N, Kuroyanagi Y, Iwai M, Hori K, Shimojima M, Ohta H. MYB-like transcription factor NoPSR1 is crucial for membrane lipid remodeling under phosphate starvation in the oleaginous microalga Nannochloropsis oceanica. FEBS Lett 2020; 594:3384-3394. [PMID: 32770739 DOI: 10.1002/1873-3468.13902] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 08/03/2020] [Accepted: 08/03/2020] [Indexed: 11/07/2022]
Abstract
Membrane lipid remodeling under phosphate (Pi) limitation, a process that replaces structural membrane phospholipids with nonphosphorus lipids, is a widely observed adaptive response in plants and algae. Here, we identified the transcription factor phosphorus starvation response 1 (NoPSR1) as an indispensable player for regulating membrane lipid conversion during Pi starvation in the microalga Nannochloropsis oceanica. Knocking out NoPSR1 scarcely perturbed membrane lipid composition under Pi-sufficient conditions but significantly impaired dynamic alteration in membrane lipids during Pi starvation. In contrast, the absence of NoPSR1 led to no obvious change in cell proliferation or storage lipid accumulation under either nutrient-sufficient or Pi-deficient conditions. Our results demonstrate a key factor controlling the membrane lipid profile during the Pi starvation response in N. oceanica.
Collapse
Affiliation(s)
- Hiroki Murakami
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Natsue Kakutani
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yunato Kuroyanagi
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Masako Iwai
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Koichi Hori
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Mie Shimojima
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroyuki Ohta
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| |
Collapse
|
28
|
Yang H, Hu C. Regulation and remodeling of intermediate metabolite and membrane lipid during NaCl-induced stress in freshwater microalga Micractinium sp. XJ-2 for biofuel production. Biotechnol Bioeng 2020; 117:3727-3738. [PMID: 32749671 DOI: 10.1002/bit.27528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/25/2020] [Accepted: 08/03/2020] [Indexed: 01/23/2023]
Abstract
Microalgae can accumulate a large fraction of reduced carbon as lipids under NaCl stress. This study investigated the mechanism of carbon allocation and reduction and triacylglycerol (TAG) accumulation in microalgae under NaCl-induced stress. Micractinium sp. XJ-2 was exposed to NaCl stress and cells were subjected to physiological, biochemical, and metabolic analyses to elucidate the stress-responsive mechanism. Lipid increased with NaCl concentration after 0-12 hr, then stabilized after 12-48 hr, and finally decreased after 48-72 hr, whereas TAG increased (0-48 hr) and then decreased (48-72 hr). Under NaCl-induced stress at lower concentrations, TAG accumulation, at first, mainly shown to rely on the carbon fixation through photosynthetic fixation, carbohydrate degradation, and membrane lipids remodeling. Moreover, carbon compounds generated by the degradation of some amino acids were reallocated and enhanced fatty acid synthesis. The remodeling of the membrane lipids of NaCl-induced microalgae relied on the following processes: (a) Increase in the amount of phospholipids and reduction in the amount of glycolipids and (b) extension of long-chain fatty acids. This study enhances our understanding of TAG production under NaCl stress and thus will provide a theoretical basis for the industrial application of NaCl-induced in the microalgal biodiesel industry.
Collapse
Affiliation(s)
- Haijian Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Chunxiang Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| |
Collapse
|
29
|
Le T, Le SC, Zhang Y, Liang P, Yang H. Evidence that polyphenols do not inhibit the phospholipid scramblase TMEM16F. J Biol Chem 2020; 295:12537-12544. [PMID: 32709749 DOI: 10.1074/jbc.ac120.014872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/23/2020] [Indexed: 01/06/2023] Open
Abstract
TMEM16 Ca2+-activated phospholipid scramblases (CaPLSases) mediate rapid transmembrane phospholipid flip-flop and as such play essential roles in various physiological and pathological processes such as blood coagulation, skeletal development, viral infection, cell-cell fusion, and ataxia. Pharmacological tools specifically targeting TMEM16 CaPLSases are urgently needed to understand these novel membrane transporters and their contributions to health and disease. Tannic acid (TA) and epigallocatechin gallate (EGCG) were recently reported as promising TMEM16F CaPLSase inhibitors. However, our present study shows that TA and EGCG do not inhibit the phospholipid-scrambling or ion conduction activities of the dual-functional TMEM16F. Instead, we found that TA and EGCG mainly acted as fluorescence quenchers that rapidly suppress the fluorophores conjugated to annexin V, a phosphatidylserine-binding probe commonly used to report on TMEM16 CaPLSase activity. These data demonstrate the false positive effects of TA and EGCG on inhibiting TMEM16F phospholipid scrambling and discourage the use of these polyphenols as CaPLSase inhibitors. Appropriate controls as well as a combination of both fluorescence imaging and electrophysiological validation are necessary in future endeavors to develop TMEM16 CaPLSase inhibitors.
Collapse
Affiliation(s)
- Trieu Le
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA
| | - Son C Le
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA
| | - Yang Zhang
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA
| | - Pengfei Liang
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA
| | - Huanghe Yang
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA .,Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, USA
| |
Collapse
|
30
|
Tallorin L, Villareal VA, Hsia CY, Rodgers MA, Burri DJ, Pfeil MP, Llopis PM, Lindenbach BD, Yang PL. Hepatitis C virus NS3-4A protease regulates the lipid environment for RNA replication by cleaving host enzyme 24-dehydrocholesterol reductase. J Biol Chem 2020; 295:12426-12436. [PMID: 32641492 PMCID: PMC7458815 DOI: 10.1074/jbc.ra120.013455] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/29/2020] [Indexed: 12/12/2022] Open
Abstract
Many RNA viruses create specialized membranes for genome replication by manipulating host lipid metabolism and trafficking, but in most cases, we do not know the molecular mechanisms responsible or how specific lipids may impact the associated membrane and viral process. For example, hepatitis C virus (HCV) causes a specific, large-fold increase in the steady-state abundance of intracellular desmosterol, an immediate precursor of cholesterol, resulting in increased fluidity of the membrane where HCV RNA replication occurs. Here, we establish the mechanism responsible for HCV's effect on intracellular desmosterol, whereby the HCV NS3-4A protease controls activity of 24-dehydrocholesterol reductase (DHCR24), the enzyme that catalyzes conversion of desmosterol to cholesterol. Our cumulative evidence for the proposed mechanism includes immunofluorescence microscopy experiments showing co-occurrence of DHCR24 and HCV NS3-4A protease; formation of an additional, faster-migrating DHCR24 species (DHCR24*) in cells harboring a HCV subgenomic replicon RNA or ectopically expressing NS3-4A; and biochemical evidence that NS3-4A cleaves DHCR24 to produce DHCR24* in vitro and in vivo. We further demonstrate that NS3-4A cleaves DHCR24 between residues Cys91 and Thr92 and show that this reduces the intracellular conversion of desmosterol to cholesterol. Together, these studies demonstrate that NS3-4A directly cleaves DHCR24 and that this results in the enrichment of desmosterol in the membranes where NS3-4A and DHCR24 co-occur. Overall, this suggests a model in which HCV directly regulates the lipid environment for RNA replication through direct effects on the host lipid metabolism.
Collapse
Affiliation(s)
- Lorillee Tallorin
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Valerie A Villareal
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Chih-Yun Hsia
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Mary A Rodgers
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Dominique J Burri
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Marc-Philipp Pfeil
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Paula Montero Llopis
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Brett D Lindenbach
- Department of Microbial Pathogenesis, Yale Medical School, New Haven, Connecticut, USA
| | - Priscilla L Yang
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
31
|
Sutkeviciute I, Vilardaga JP. Structural insights into emergent signaling modes of G protein-coupled receptors. J Biol Chem 2020; 295:11626-11642. [PMID: 32571882 DOI: 10.1074/jbc.rev120.009348] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 06/21/2020] [Indexed: 12/21/2022] Open
Abstract
G protein-coupled receptors (GPCRs) represent the largest family of cell membrane proteins, with >800 GPCRs in humans alone, and recognize highly diverse ligands, ranging from photons to large protein molecules. Very important to human medicine, GPCRs are targeted by about 35% of prescription drugs. GPCRs are characterized by a seven-transmembrane α-helical structure, transmitting extracellular signals into cells to regulate major physiological processes via heterotrimeric G proteins and β-arrestins. Initially viewed as receptors whose signaling via G proteins is delimited to the plasma membrane, it is now recognized that GPCRs signal also at various intracellular locations, and the mechanisms and (patho)physiological relevance of such signaling modes are actively investigated. The propensity of GPCRs to adopt different signaling modes is largely encoded in the structural plasticity of the receptors themselves and of their signaling complexes. Here, we review emerging modes of GPCR signaling via endosomal membranes and the physiological implications of such signaling modes. We further summarize recent structural insights into mechanisms of GPCR activation and signaling. We particularly emphasize the structural mechanisms governing the continued GPCR signaling from endosomes and the structural aspects of the GPCR resensitization mechanism and discuss the recently uncovered and important roles of lipids in these processes.
Collapse
Affiliation(s)
- Ieva Sutkeviciute
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
32
|
Majumder S, Kono M, Lee YT, Byrnes C, Li C, Tuymetova G, Proia RL. A genome-wide CRISPR/Cas9 screen reveals that the aryl hydrocarbon receptor stimulates sphingolipid levels. J Biol Chem 2020; 295:4341-4349. [PMID: 32029474 PMCID: PMC7105297 DOI: 10.1074/jbc.ac119.011170] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 01/28/2020] [Indexed: 01/12/2023] Open
Abstract
Sphingolipid biosynthesis generates lipids for membranes and signaling that are crucial for many developmental and physiological processes. In some cases, large amounts of specific sphingolipids must be synthesized for specialized physiological functions, such as during axon myelination. How sphingolipid synthesis is regulated to fulfill these physiological requirements is not known. To identify genes that positively regulate membrane sphingolipid levels, here we employed a genome-wide CRISPR/Cas9 loss-of-function screen in HeLa cells using selection for resistance to Shiga toxin, which uses a plasma membrane-associated glycosphingolipid, globotriaosylceramide (Gb3), for its uptake. The screen identified several genes in the sphingolipid biosynthetic pathway that are required for Gb3 synthesis, and it also identified the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor widely involved in development and physiology, as being required for Gb3 biosynthesis. AHR bound and activated the gene promoter of serine palmitoyltransferase small subunit A (SPTSSA), which encodes a subunit of the serine palmitoyltransferase that catalyzes the first and rate-limiting step in de novo sphingolipid biosynthesis. AHR knockout HeLa cells exhibited significantly reduced levels of cell-surface Gb3, and both AHR knockout HeLa cells and tissues from Ahr knockout mice displayed decreased sphingolipid content as well as significantly reduced expression of several key genes in the sphingolipid biosynthetic pathway. The sciatic nerve of Ahr knockout mice exhibited both reduced ceramide content and reduced myelin thickness. These results indicate that AHR up-regulates sphingolipid levels and is important for full axon myelination, which requires elevated levels of membrane sphingolipids.
Collapse
Affiliation(s)
- Saurav Majumder
- Genetics of Development and Disease Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Mari Kono
- Genetics of Development and Disease Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Y Terry Lee
- Genetics of Development and Disease Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Colleen Byrnes
- Genetics of Development and Disease Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Cuiling Li
- Genetics of Development and Disease Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Galina Tuymetova
- Genetics of Development and Disease Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Richard L Proia
- Genetics of Development and Disease Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892.
| |
Collapse
|
33
|
Ali MH, Sobze JM, Pham TH, Nadeem M, Liu C, Galagedara L, Cheema M, Thomas R. Carbon Nanoparticles Functionalized with Carboxylic Acid Improved the Germination and Seedling Vigor in Upland Boreal Forest Species. Nanomaterials (Basel) 2020; 10:nano10010176. [PMID: 31968542 PMCID: PMC7023356 DOI: 10.3390/nano10010176] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/14/2019] [Accepted: 01/14/2020] [Indexed: 12/21/2022]
Abstract
Nanopriming has been shown to significantly improve seed germination and seedling vigor in several agricultural crops. However, this approach has not been applied to native upland boreal forest species with complex seed dormancy to improve propagation. Herein, we demonstrate the effectiveness of carbon nanoparticles functionalized with carboxylic acids in resolving seed dormancy and improved the propagation of two native upland boreal forest species. Seed priming with carbon nanoparticles functionalized with carboxylic acids followed by stratification were observed to be the most effective in improving germination to 90% in green alder (Alnus viridis L.) compared to 60% in the control. Conversely, a combination of carbon nanoparticles (CNPs), especially multiwall carbon nanoparticles functionalized with carboxylic acid (MWCNT–COOH), cold stratification, mechanical scarification and hormonal priming (gibberellic acid) was effective for buffaloberry seeds (Shepherdia canadensis L.). Both concentrations (20 µg and 40 µg) of MWCNT–COOH had a higher percent germination (90%) compared to all other treatments. Furthermore, we observed the improvement in germination, seedling vigor and resolution of both embryo and seed coat dormancy in upland boreal forest species appears to be associated with the remodeling of C18:3 enriched fatty acids in the following seed membrane lipid molecular species: PC18:1/18:3, PG16:1/18:3, PE18:3/18:2, and digalactosyldiacylglycerol (DGDG18:3/18:3). These findings suggest that nanopriming may be a useful approach to resolve seed dormancy issues and improve the seed germination in non-resource upland boreal forest species ideally suited for forest reclamation following resource mining.
Collapse
Affiliation(s)
- Md. Hossen Ali
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Jean-Marie Sobze
- Northern Alberta Institute of Technology, 8102-99 Avenue, Peace River, AL T8S 1R2, Canada;
| | - Thu Huong Pham
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Muhammad Nadeem
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
- Correspondence: (M.N.); (R.T.)
| | - Chen Liu
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Lakshman Galagedara
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Mumtaz Cheema
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
| | - Raymond Thomas
- School of Science and the Environment/Boreal Ecosystem Research Facility, Grenfell Campus, Memorial University of Newfoundland, Corner Brook, NL A2H 5G5, Canada; (M.H.A.); (T.H.P.); (C.L.); (L.G.); (M.C.)
- Correspondence: (M.N.); (R.T.)
| |
Collapse
|
34
|
Oluba OM. Erythrocyte Lipid and Antioxidant Changes in <i>Plasmodium falciparum</i>-infected Children Attending Mother and Child Hospital in Akure, Nigeria. Pak J Biol Sci 2020; 22:257-264. [PMID: 31930848 DOI: 10.3923/pjbs.2019.257.264] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND OBJECTIVE Understanding the molecular and cellular pathways activated in response to Plasmodium falciparum infection is crucial for the development of pharmacological intervention to malaria. The present study was designed to evaluate the lipid components and the oxidative status of erythrocyte obtained from children under 5 years infected with Plasmodium falciparum. MATERIALS AND METHODS Parasitemia was assessed prior and after treatment with antimalarial, erythrocyte lipid profile, levels of lipid peroxidation and antioxidant status (reduced glutathione, GSH; superoxide dismutase, SOD; catalase and glutathione peroxidase, GPx) were measured. RESULTS Results obtained showed that in Plasmodium infected erythrocyte, the total phospholipids, cholesterol and LDL-cholesterol concentrations were significantly elevated beyond the normal level. In addition, an upsurge in erythrocyte oxidant (lipid peroxide) status with a concomitant downregulation of the antioxidant status (GSH concentration and SOD, catalase and GPx activities) was observed in P. falciparum-infected children. However, following a three-day treatment with artemisinin combination drugs, there was a significant reduction in erythrocyte phospholipids, total cholesterol and LDL-cholesterol concentration as well as lipid peroxide levels. Significant augmentation in erythrocyte antioxidant status (GSH, SOD, catalase and GPx) were also observed after treatment with antimalarials. CONCLUSION This study demonstrated that erythrocyte lipids and oxidative status are usually altered in Plasmodium falciparum-infected children. Thus, monitoring erythrocyte lipid profile and oxidative status could offer a viable diagnostic strategy in early detection of malaria in children.
Collapse
|
35
|
Tietz S, Leuenberger M, Höhner R, Olson AH, Fleming GR, Kirchhoff H. A proteoliposome-based system reveals how lipids control photosynthetic light harvesting. J Biol Chem 2020; 295:1857-1866. [PMID: 31929108 DOI: 10.1074/jbc.ra119.011707] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/09/2020] [Indexed: 11/06/2022] Open
Abstract
Integral membrane proteins are exposed to a complex and dynamic lipid environment modulated by nonbilayer lipids that can influence protein functions by lipid-protein interactions. The nonbilayer lipid monogalactosyldiacylglycerol (MGDG) is the most abundant lipid in plant photosynthetic thylakoid membranes, but its impact on the functionality of energy-converting membrane protein complexes is unknown. Here, we optimized a detergent-based reconstitution protocol to develop a proteoliposome technique that incorporates the major light-harvesting complex II (LHCII) into compositionally well-defined large unilamellar lipid bilayer vesicles to study the impact of MGDG on light harvesting by LHCII. Using steady-state fluorescence spectroscopy, CD spectroscopy, and time-correlated single-photon counting, we found that both chlorophyll fluorescence quantum yields and fluorescence lifetimes clearly indicate that the presence of MGDG in lipid bilayers switches LHCII from a light-harvesting to a more energy-quenching mode that dissipates harvested light into heat. It is hypothesized that in the in vitro system developed here, MGDG controls light harvesting of LHCII by modulating the hydrostatic lateral membrane pressure profile in the lipid bilayer sensed by LHCII-bound peripheral pigments.
Collapse
Affiliation(s)
- Stefanie Tietz
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164-6340
| | - Michelle Leuenberger
- Department of Chemistry, University of California, Berkeley, California 94720; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Ricarda Höhner
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164-6340
| | - Alice H Olson
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164-6340
| | - Graham R Fleming
- Department of Chemistry, University of California, Berkeley, California 94720; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164-6340.
| |
Collapse
|
36
|
Salimi H, Johnson J, Flores MG, Zhang MS, O'Malley Y, Houtman JC, Schlievert PM, Haim H. The lipid membrane of HIV-1 stabilizes the viral envelope glycoproteins and modulates their sensitivity to antibody neutralization. J Biol Chem 2019; 295:348-362. [PMID: 31757809 DOI: 10.1074/jbc.ra119.009481] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/19/2019] [Indexed: 11/06/2022] Open
Abstract
The envelope glycoproteins (Envs) of HIV-1 are embedded in the cholesterol-rich lipid membrane of the virus. Chemical depletion of cholesterol from HIV-1 particles inactivates their infectivity. We observed that diverse HIV-1 strains exhibit a range of sensitivities to such treatment. Differences in sensitivity to cholesterol depletion could not be explained by variation in Env components known to interact with cholesterol, including the cholesterol-recognition motif and cytoplasmic tail of gp41. Using antibody-binding assays, measurements of virus infectivity, and analyses of lipid membrane order, we found that depletion of cholesterol from HIV-1 particles decreases the conformational stability of Env. It enhances exposure of partially cryptic epitopes on the trimer and increases sensitivity to structure-perturbing treatments such as antibodies and cold denaturation. Substitutions in the cholesterol-interacting motif of gp41 induced similar effects as depletion of cholesterol. Surface-acting agents, which are incorporated into the virus lipid membrane, caused similar effects as disruption of the Env-cholesterol interaction. Furthermore, substitutions in gp120 that increased structural stability of Env (i.e. induced a "closed" conformation of the trimer) increased virus resistance to cholesterol depletion and to the surface-acting agents. Collectively, these results indicate a critical contribution of the viral membrane to the stability of the Env trimer and to neutralization resistance against antibodies. Our findings suggest that the potency of poorly neutralizing antibodies, which are commonly elicited in vaccinated individuals, may be markedly enhanced by altering the lipid composition of the viral membrane.
Collapse
Affiliation(s)
- Hamid Salimi
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jacklyn Johnson
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Manuel G Flores
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Michael S Zhang
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Yunxia O'Malley
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jon C Houtman
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Patrick M Schlievert
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Hillel Haim
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
| |
Collapse
|
37
|
Sasaki M, Nishikawa H, Suzuki S, Moser M, Huber M, Sawasato K, Matsubayashi HT, Kumazaki K, Tsukazaki T, Kuruma Y, Nureki O, Ueda T, Nishiyama KI. The bacterial protein YidC accelerates MPIase-dependent integration of membrane proteins. J Biol Chem 2019; 294:18898-18908. [PMID: 31662434 DOI: 10.1074/jbc.ra119.011248] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/25/2019] [Indexed: 01/06/2023] Open
Abstract
Bacterial membrane proteins are integrated into membranes through the concerted activities of a series of integration factors, including membrane protein integrase (MPIase). However, how MPIase activity is complemented by other integration factors during membrane protein integration is incompletely understood. Here, using inverted inner-membrane vesicle and reconstituted (proteo)liposome preparations from Escherichia coli cells, along with membrane protein integration assays and the PURE system to produce membrane proteins, we found that anti-MPIase IgG inhibits the integration of both the Sec-independent substrate 3L-Pf3 coat and the Sec-dependent substrate MtlA into E. coli membrane vesicles. MPIase-depleted membrane vesicles lacked both 3L-Pf3 coat and MtlA integration, indicating that MPIase is involved in the integration of both proteins. We developed a reconstitution system in which disordered spontaneous integration was precluded, which revealed that SecYEG, YidC, or both, are not sufficient for Sec-dependent and -independent integration. Although YidC had no effect on MPIase-dependent integration of Sec-independent substrates in the conventional assay system, YidC significantly accelerated the integration when the substrate amounts were increased in our PURE system-based assay. Similar acceleration by YidC was observed for MtlA integration. YidC mutants with amino acid substitutions in the hydrophilic cavity inside the membrane were defective in the acceleration of the Sec-independent integration. Of note, MPIase was up-regulated upon YidC depletion. These results indicate that YidC accelerates the MPIase-dependent integration of membrane proteins, suggesting that MPIase and YidC function sequentially and cooperatively during the catalytic cycle of membrane protein integration.
Collapse
Affiliation(s)
- Masaru Sasaki
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Hanako Nishikawa
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Sonomi Suzuki
- Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Michael Moser
- Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Maria Huber
- Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Katsuhiro Sawasato
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Hideaki T Matsubayashi
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Kaoru Kumazaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | | | - Yutetsu Kuruma
- Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan; PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Ken-Ichi Nishiyama
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan; Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan; Department of Biological Chemistry and Food Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan.
| |
Collapse
|
38
|
Caldo KMP, Xu Y, Falarz L, Jayawardhane K, Acedo JZ, Chen G. Arabidopsis CTP:phosphocholine cytidylyltransferase 1 is phosphorylated and inhibited by sucrose nonfermenting 1-related protein kinase 1 (SnRK1). J Biol Chem 2019; 294:15862-15874. [PMID: 31439667 PMCID: PMC6816107 DOI: 10.1074/jbc.ra119.008047] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 08/19/2019] [Indexed: 11/06/2022] Open
Abstract
De novo phosphatidylcholine (PC) biosynthesis via the Kennedy pathway involves highly endergonic biochemical reactions that must be fine-tuned with energy homeostasis. Previous studies have shown that CTP:phosphocholine cytidylyltransferase (CCT) is an important regulatory enzyme in this pathway and that its activity can be controlled at both transcriptional and posttranslational levels. Here we identified an important additional mechanism regulating plant CCT1 activity. Comparative analysis revealed that Arabidopsis CCT1 (AtCCT1) contains catalytic and membrane-binding domains that are homologous to those of rat CCT1. In contrast, the C-terminal phosphorylation domain important for stringent regulation of rat CCT1 was apparently missing in AtCCT1. Instead, we found that AtCCT1 contains a putative consensus site (Ser-187) for modification by sucrose nonfermenting 1-related protein kinase 1 (SnRK1 or KIN10/SnRK1.1), involved in energy homeostasis. Phos-tag SDS-PAGE coupled with MS analysis disclosed that SnRK1 indeed phosphorylates AtCCT1 at Ser-187, and we found that AtCCT1 phosphorylation substantially reduces its activity by as much as 70%. An S187A variant exhibited decreased activity, indicating the importance of Ser-187 in catalysis, and this variant was less susceptible to SnRK1-mediated inhibition. Protein truncation and liposome binding studies indicated that SnRK1-mediated AtCCT1 phosphorylation directly affects the catalytic domain rather than interfering with phosphatidate-mediated AtCCT1 activation. Overexpression of the AtCCT1 catalytic domain in Nicotiana benthamiana leaves increased PC content, and SnRK1 co-expression reduced this effect. Taken together, our results suggest that SnRK1 mediates the phosphorylation and concomitant inhibition of AtCCT1, revealing an additional mode of regulation for this key enzyme in plant PC biosynthesis.
Collapse
Affiliation(s)
- Kristian Mark P Caldo
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Yang Xu
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Lucas Falarz
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Kethmi Jayawardhane
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Jeella Z Acedo
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| |
Collapse
|
39
|
Sparks RP, Arango AS, Starr ML, Aboff ZL, Hurst LR, Rivera-Kohr DA, Zhang C, Harnden KA, Jenkins JL, Guida WC, Tajkhorshid E, Fratti RA. A small-molecule competitive inhibitor of phosphatidic acid binding by the AAA+ protein NSF/Sec18 blocks the SNARE-priming stage of vacuole fusion. J Biol Chem 2019; 294:17168-17185. [PMID: 31515268 DOI: 10.1074/jbc.ra119.008865] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 09/04/2019] [Indexed: 12/13/2022] Open
Abstract
The homeostasis of most organelles requires membrane fusion mediated by soluble N -ethylmaleimide-sensitive factor (NSF) attachment protein receptors (SNAREs). SNAREs undergo cycles of activation and deactivation as membranes move through the fusion cycle. At the top of the cycle, inactive cis-SNARE complexes on a single membrane are activated, or primed, by the hexameric ATPase associated with the diverse cellular activities (AAA+) protein, N-ethylmaleimide-sensitive factor (NSF/Sec18), and its co-chaperone α-SNAP/Sec17. Sec18-mediated ATP hydrolysis drives the mechanical disassembly of SNAREs into individual coils, permitting a new cycle of fusion. Previously, we found that Sec18 monomers are sequestered away from SNAREs by binding phosphatidic acid (PA). Sec18 is released from the membrane when PA is hydrolyzed to diacylglycerol by the PA phosphatase Pah1. Although PA can inhibit SNARE priming, it binds other proteins and thus cannot be used as a specific tool to further probe Sec18 activity. Here, we report the discovery of a small-molecule compound, we call IPA (inhibitor of priming activity), that binds Sec18 with high affinity and blocks SNARE activation. We observed that IPA blocks SNARE priming and competes for PA binding to Sec18. Molecular dynamics simulations revealed that IPA induces a more rigid NSF/Sec18 conformation, which potentially disables the flexibility required for Sec18 to bind to PA or to activate SNAREs. We also show that IPA more potently and specifically inhibits NSF/Sec18 activity than does N-ethylmaleimide, requiring the administration of only low micromolar concentrations of IPA, demonstrating that this compound could help to further elucidate SNARE-priming dynamics.
Collapse
Affiliation(s)
- Robert P Sparks
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Andres S Arango
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Matthew L Starr
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Zachary L Aboff
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Logan R Hurst
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - David A Rivera-Kohr
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Chi Zhang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Kevin A Harnden
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Jermaine L Jenkins
- Structural Biology and Biophysics Facility, University of Rochester Medical Center, Rochester, New York 14642
| | - Wayne C Guida
- Department of Chemistry, University of South Florida, Tampa, Florida 336204
| | - Emad Tajkhorshid
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Rutilio A Fratti
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 .,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| |
Collapse
|
40
|
Dey P, Su WM, Mirheydari M, Han GS, Carman GM. Protein kinase C mediates the phosphorylation of the Nem1-Spo7 protein phosphatase complex in yeast. J Biol Chem 2019; 294:15997-16009. [PMID: 31501244 DOI: 10.1074/jbc.ra119.010592] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/04/2019] [Indexed: 12/18/2022] Open
Abstract
The Nem1-Spo7 complex in the yeast Saccharomyces cerevisiae is a protein phosphatase required for the nuclear/endoplasmic reticulum membrane localization of Pah1, a phosphatidate phosphatase that produces diacylglycerol for triacylglycerol synthesis at the expense of phospholipid synthesis. In a previous study, we showed that the protein phosphatase is subject to phosphorylation by protein kinase A (PKA). Here, we demonstrate that Nem1-Spo7 is regulated through its phosphorylation by protein kinase C (PKC), which plays multiple roles, including the regulation of lipid synthesis and cell wall integrity. Phosphorylation analyses of Nem1-Spo7 and its synthetic peptides indicate that both subunits of the complex are bona fide PKC substrates. Site-directed mutagenesis of NEM1 and SPO7, coupled with phosphopeptide mapping and immunoblotting with a phosphoserine-specific PKC substrate antibody, revealed that Ser-201 in Nem1 and Ser-22/Ser-28 in Spo7 are major PKC target sites of phosphorylation. Activity analysis of mutant Nem1-Spo7 complexes indicates that the PKC phosphorylation of Nem1 exerts a stimulatory effect, but the phosphorylation of Spo7 has no effect. Lipid-labeling analysis of cells expressing the phosphorylation-deficient alleles of NEM1 and SPO7 indicates that the stimulation of the Nem1-Spo7 activity has the effect of increasing triacylglycerol synthesis. Prephosphorylation of Nem1-Spo7 by PKC inhibits the PKA phosphorylation of Nem1, whereas prephosphorylation of the phosphatase complex by PKA inhibits the PKC phosphorylation of Spo7. Collectively, this work advances the understanding of the Nem1-Spo7 regulation by phosphorylation and its impact on lipid synthesis.
Collapse
Affiliation(s)
- Prabuddha Dey
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Wen-Min Su
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - Mona Mirheydari
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, New Jersey 08901
| | - 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, New Jersey 08901
| | - 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, New Jersey 08901
| |
Collapse
|
41
|
Szabó A, Fébel H, Ali O, Kovács M. Fumonisin B 1 induced compositional modifications of the renal and hepatic membrane lipids in rats - Dose and exposure time dependence. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2019; 36:1722-1739. [PMID: 31437116 DOI: 10.1080/19440049.2019.1652772] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Male Wistar rats were intraperitoneally dosed with fumonisin B1 (FB1; 0, 20, 50 and 100 mg kg-1 dietary dose equivalent) for 5 & 10 days to assess dose- and time-dependent effects on renal and hepatic phosphatidylcholine (PC), phosphatidylinositol (PI) and phosphatidylethanolamine (PE) fatty acid (FA) profiles. Renal PC showed increasing FA saturation (SAT) after 5 days; after 10 days polyunsaturation (PUFA) decreased markedly (Σ n3 (total n3), Σ n6, PUFA, unsaturation index (UI) and average FA chain length (ACL)), mostly with linear dose response. In the PI FAs similar changes were observed, decreasing monounsaturated FA, PUFA, UI and ACL (5 & 10 days), while the PE fraction was responsive in Σ n6 (↓) and SAT (↑), but only after 5 days (without dose response for both PI & PE). Liver PC exhibited increasing saturation (C16:0), decreasing polyunsaturation (C20:3 n6 [dihomo-γ-linolenic acid, DGLA]; C20:3 n3); the PI FA profile showed similar alterations after 5 days. PC & PI FA failed to respond in a dose-dependent manner to FB1. In PE FA profile DGLA decreased, with a decrease of the total n6 FA proportion and dose-dependent increase of n3 FAs. Results revealed expressed renal sensitivity, supporting our earlier published results in terms of oxidative stress and histopathological modifications.
Collapse
Affiliation(s)
- András Szabó
- MTA-KE-SZIE Mycotoxins in the Food Chain Research Group, Kaposvár University, Kaposvár, Hungary.,Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár, Hungary
| | - Hedvig Fébel
- National Agricultural Research and Innovation Centre, Research Institute for Animal Breeding, Nutrition and Meat Science, Herceghalom, Hungary
| | - Omeralfaroug Ali
- Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár, Hungary
| | - Melinda Kovács
- MTA-KE-SZIE Mycotoxins in the Food Chain Research Group, Kaposvár University, Kaposvár, Hungary.,Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár, Hungary
| |
Collapse
|
42
|
Petkevicius K, Virtue S, Bidault G, Jenkins B, Çubuk C, Morgantini C, Aouadi M, Dopazo J, Serlie MJ, Koulman A, Vidal-Puig A. Accelerated phosphatidylcholine turnover in macrophages promotes adipose tissue inflammation in obesity. eLife 2019; 8:e47990. [PMID: 31418690 PMCID: PMC6748830 DOI: 10.7554/elife.47990] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/15/2019] [Indexed: 12/28/2022] Open
Abstract
White adipose tissue (WAT) inflammation contributes to the development of insulin resistance in obesity. While the role of adipose tissue macrophage (ATM) pro-inflammatory signalling in the development of insulin resistance has been established, it is less clear how WAT inflammation is initiated. Here, we show that ATMs isolated from obese mice and humans exhibit markers of increased rate of de novo phosphatidylcholine (PC) biosynthesis. Macrophage-specific knockout of phosphocholine cytidylyltransferase A (CCTα), the rate-limiting enzyme of de novo PC biosynthesis pathway, alleviated obesity-induced WAT inflammation and insulin resistance. Mechanistically, CCTα-deficient macrophages showed reduced ER stress and inflammation in response to palmitate. Surprisingly, this was not due to lower exogenous palmitate incorporation into cellular PCs. Instead, CCTα-null macrophages had lower membrane PC turnover, leading to elevated membrane polyunsaturated fatty acid levels that negated the pro-inflammatory effects of palmitate. Our results reveal a causal link between obesity-associated increase in de novo PC synthesis, accelerated PC turnover and pro-inflammatory activation of ATMs.
Collapse
Affiliation(s)
- Kasparas Petkevicius
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRCCambridgeUnited Kingdom
| | - Sam Virtue
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRCCambridgeUnited Kingdom
| | - Guillaume Bidault
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRCCambridgeUnited Kingdom
| | - Benjamin Jenkins
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRCCambridgeUnited Kingdom
| | - Cankut Çubuk
- Clinical Bioinformatics AreaFundación Progreso y Salud, CDCA, Hospital Virgen del RocioSevillaSpain
- Functional Genomics NodeINB-ELIXIR-es, FPS, Hospital Virgen del RocioSevillaSpain
- Bioinformatics in Rare Diseases (BiER)Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), FPS, Hospital Virgen del RocioSevillaSpain
| | - Cecilia Morgantini
- Department of Medicine, Integrated Cardio Metabolic CentreKarolinska InstitutetHuddingeSweden
| | - Myriam Aouadi
- Department of Medicine, Integrated Cardio Metabolic CentreKarolinska InstitutetHuddingeSweden
| | - Joaquin Dopazo
- Clinical Bioinformatics AreaFundación Progreso y Salud, CDCA, Hospital Virgen del RocioSevillaSpain
- Functional Genomics NodeINB-ELIXIR-es, FPS, Hospital Virgen del RocioSevillaSpain
- Bioinformatics in Rare Diseases (BiER)Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), FPS, Hospital Virgen del RocioSevillaSpain
| | - Mireille J Serlie
- Department of Endocrinology and MetabolismAmsterdam University Medical CenterAmsterdamNetherlands
| | - Albert Koulman
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRCCambridgeUnited Kingdom
| | - Antonio Vidal-Puig
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, MDU MRCCambridgeUnited Kingdom
- Wellcome Trust Sanger InstituteHinxtonUnited Kingdom
| |
Collapse
|
43
|
Nguyen VC, Nakamura Y, Kanehara K. Membrane lipid polyunsaturation mediated by FATTY ACID DESATURASE 2 (FAD2) is involved in endoplasmic reticulum stress tolerance in Arabidopsis thaliana. Plant J 2019; 99:478-493. [PMID: 31001857 DOI: 10.1111/tpj.14338] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/19/2019] [Accepted: 03/27/2019] [Indexed: 05/22/2023]
Abstract
Unsaturation of membrane glycerolipid classes at their hydrophobic fatty acid tails critically affects the physical nature of the lipid molecule. In Arabidopsis thaliana, 7 fatty acid desaturases (FADs) differently desaturate each glycerolipid class in plastids and the endoplasmic reticulum (ER). Here, we showed that polyunsaturation of ER glycerolipids is required for the ER stress response. Through systematic screening of FAD mutants, we found that a mutant of FAD2 resulted in a hypersensitive response to tunicamycin, a chemical inducer of ER stress. FAD2 converts oleic acid to linoleic acid of the fatty acyl groups of ER-synthesized phospholipids. Our functional in vivo reporter assay revealed the ER localization and distinct tissue-specific expression patterns of FAD2. Moreover, glycerolipid profiling of both mutants and overexpressors of FAD2 under tunicamycin-induced ER stress conditions, along with phenotypic screening of the mutants of the FAD family, suggested that the ratio of monounsaturated fatty acids to polyunsaturated fatty acids, particularly 18:1 to 18:2 species, may be an important factor in allowing the ER membrane to cope with ER stress. Therefore, our results suggest that membrane lipid polyunsaturation mediated by FAD2 is involved in ER stress tolerance in Arabidopsis.
Collapse
Affiliation(s)
- Van Cam Nguyen
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taipei, 11529, Taiwan
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Yuki Nakamura
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taipei, 11529, Taiwan
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Kazue Kanehara
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taipei, 11529, Taiwan
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan
- Department of Applied Science and Engineering, Muroran Institute of Technology, Muroran, Hokkaido, 050-8585, Japan
| |
Collapse
|
44
|
Pinkwart K, Schneider F, Lukoseviciute M, Sauka-Spengler T, Lyman E, Eggeling C, Sezgin E. Nanoscale dynamics of cholesterol in the cell membrane. J Biol Chem 2019; 294:12599-12609. [PMID: 31270209 PMCID: PMC6709632 DOI: 10.1074/jbc.ra119.009683] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 06/26/2019] [Indexed: 12/22/2022] Open
Abstract
Cholesterol constitutes ∼30-40% of the mammalian plasma membrane, a larger fraction than of any other single component. It is a major player in numerous signaling processes as well as in shaping molecular membrane architecture. However, our knowledge of the dynamics of cholesterol in the plasma membrane is limited, restricting our understanding of the mechanisms regulating its involvement in cell signaling. Here, we applied advanced fluorescence imaging and spectroscopy approaches on in vitro (model membranes) and in vivo (live cells and embryos) membranes as well as in silico analysis to systematically study the nanoscale dynamics of cholesterol in biological membranes. Our results indicate that cholesterol diffuses faster than phospholipids in live membranes, but not in model membranes. Interestingly, a detailed statistical diffusion analysis suggested two-component diffusion for cholesterol in the plasma membrane of live cells. One of these components was similar to a freely diffusing phospholipid analogue, whereas the other one was significantly faster. When a cholesterol analogue was localized to the outer leaflet only, the fast diffusion of cholesterol disappeared, and it diffused similarly to phospholipids. Overall, our results suggest that cholesterol diffusion in the cell membrane is heterogeneous and that this diffusional heterogeneity is due to cholesterol's nanoscale interactions and localization in the membrane.
Collapse
Affiliation(s)
- Kerstin Pinkwart
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Falk Schneider
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Martyna Lukoseviciute
- Radcliffe Department of Medicine, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Tatjana Sauka-Spengler
- Radcliffe Department of Medicine, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Edward Lyman
- Departments of Physics and Astronomy and Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
| | - Christian Eggeling
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom.,Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 4, 07743 Jena, Germany.,Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Erdinc Sezgin
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, United Kingdom
| |
Collapse
|
45
|
Sawasato K, Suzuki S, Nishiyama KI. Increased expression of the bacterial glycolipid MPIase is required for efficient protein translocation across membranes in cold conditions. J Biol Chem 2019; 294:8403-8411. [PMID: 30936205 DOI: 10.1074/jbc.ra119.008457] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 03/21/2019] [Indexed: 12/21/2022] Open
Abstract
Protein integration into and translocation across biological membranes are vital events for organismal survival and are fundamentally conserved among many organisms. Membrane protein integrase (MPIase) is a glycolipid that drives membrane protein integration into the cytoplasmic membrane in Escherichia coli MPIase also stimulates protein translocation across the membrane, but how its expression is regulated is incompletely understood. In this study, we found that the expression level of MPIase significantly increases in the cold (<25 °C), whereas that of the SecYEG translocon does not. Using previously created gene-knockout E. coli strains, we also found that either the cdsA or ynbB gene, both encoding rate-limiting enzymes for MPIase biosynthesis, is responsible for the increase in the MPIase expression. Furthermore, using pulse-chase experiments and protein integration assays, we demonstrated that the increase in MPIase levels is important for efficient protein translocation, but not for protein integration. We conclude that MPIase expression is required to stimulate protein translocation in cold conditions and is controlled by cdsA and ynbB gene expression.
Collapse
Affiliation(s)
- Katsuhiro Sawasato
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Sonomi Suzuki
- Department of Biological Chemistry and Food Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Ken-Ichi Nishiyama
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan; Department of Biological Chemistry and Food Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan.
| |
Collapse
|
46
|
Starr ML, Sparks RP, Arango AS, Hurst LR, Zhao Z, Lihan M, Jenkins JL, Tajkhorshid E, Fratti RA. Phosphatidic acid induces conformational changes in Sec18 protomers that prevent SNARE priming. J Biol Chem 2019; 294:3100-3116. [PMID: 30617180 PMCID: PMC6398130 DOI: 10.1074/jbc.ra118.006552] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/31/2018] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic cell homeostasis requires transfer of cellular components among organelles and relies on membrane fusion catalyzed by SNARE proteins. Inactive SNARE bundles are reactivated by hexameric N-ethylmaleimide-sensitive factor, vesicle-fusing ATPase (Sec18/NSF)-driven disassembly that enables a new round of membrane fusion. We previously found that phosphatidic acid (PA) binds Sec18 and thereby sequesters it from SNAREs and that PA dephosphorylation dissociates Sec18 from the membrane, allowing it to engage SNARE complexes. We now report that PA also induces conformational changes in Sec18 protomers and that hexameric Sec18 cannot bind PA membranes. Molecular dynamics (MD) analyses revealed that the D1 and D2 domains of Sec18 contain PA-binding sites and that the residues needed for PA binding are masked in hexameric Sec18. Importantly, these simulations also disclosed that a major conformational change occurs in the linker region between the D1 and D2 domains, which is distinct from the conformational changes that occur in hexameric Sec18 during SNARE priming. Together, these findings indicate that PA regulates Sec18 function by altering its architecture and stabilizing membrane-bound Sec18 protomers.
Collapse
Affiliation(s)
- Matthew L Starr
- From the Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Robert P Sparks
- From the Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Andres S Arango
- the Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Logan R Hurst
- From the Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Zhiyu Zhao
- the Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Muyun Lihan
- the Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Jermaine L Jenkins
- the Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York 14642
| | - Emad Tajkhorshid
- From the Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- the Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | - Rutilio A Fratti
- From the Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801,
- the Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| |
Collapse
|
47
|
Gupta A, Marzinek JK, Jefferies D, Bond PJ, Harryson P, Wohland T. The disordered plant dehydrin Lti30 protects the membrane during water-related stress by cross-linking lipids. J Biol Chem 2019; 294:6468-6482. [PMID: 30819802 DOI: 10.1074/jbc.ra118.007163] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/14/2019] [Indexed: 12/13/2022] Open
Abstract
Dehydrins are intrinsically disordered proteins, generally expressed in plants as a response to embryogenesis and water-related stress. Their suggested functions are in membrane stabilization and cell protection. All dehydrins contain at least one copy of the highly conserved K-segment, proposed to be a membrane-binding motif. The dehydrin Lti30 (Arabidopsis thaliana) is up-regulated during cold and drought stress conditions and comprises six K-segments, each with two adjacent histidines. Lti30 interacts with the membrane electrostatically via pH-dependent protonation of the histidines. In this work, we seek a molecular understanding of the membrane interaction mechanism of Lti30 by determining the diffusion and molecular organization of Lti30 on model membrane systems by imaging total internal reflection- fluorescence correlation spectroscopy (ITIR-FCS) and molecular dynamics (MD) simulations. The dependence of the diffusion coefficient explored by ITIR-FCS together with MD simulations yields insights into Lti30 binding, domain partitioning, and aggregation. The effect of Lti30 on membrane lipid diffusion was studied on fluorescently labeled supported lipid bilayers of different lipid compositions at mechanistically important pH conditions. In parallel, we compared the mode of diffusion for short individual K-segment peptides. The results indicate that Lti30 binds the lipid bilayer via electrostatics, which restricts the mobility of lipids and bound protein molecules. At low pH, Lti30 binding induced lipid microdomain formation as well as protein aggregation, which could be correlated with one another. Moreover, at physiological pH, Lti30 forms nanoscale aggregates when proximal to the membrane suggesting that Lti30 may protect the cell by "cross-linking" the membrane lipids.
Collapse
Affiliation(s)
- Anjali Gupta
- From the Center for BioImaging Sciences and.,the Department of Biological Sciences, National University of Singapore, 14 Science Dr. 4, Singapore 117543, Singapore
| | - Jan K Marzinek
- the Bioinformatics Institute (A*STAR), 30 Biopolis St., 07-01 Matrix, Singapore 138671, Singapore
| | - Damien Jefferies
- the Bioinformatics Institute (A*STAR), 30 Biopolis St., 07-01 Matrix, Singapore 138671, Singapore.,the School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Peter J Bond
- the Department of Biological Sciences, National University of Singapore, 14 Science Dr. 4, Singapore 117543, Singapore.,the Bioinformatics Institute (A*STAR), 30 Biopolis St., 07-01 Matrix, Singapore 138671, Singapore
| | - Pia Harryson
- the Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden, and
| | - Thorsten Wohland
- From the Center for BioImaging Sciences and .,the Department of Biological Sciences, National University of Singapore, 14 Science Dr. 4, Singapore 117543, Singapore.,Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| |
Collapse
|
48
|
Mikkelsen SA, Mogensen LS, Vilsen B, Molday RS, Vestergaard AL, Andersen JP. Asparagine 905 of the mammalian phospholipid flippase ATP8A2 is essential for lipid substrate-induced activation of ATP8A2 dephosphorylation. J Biol Chem 2019; 294:5970-5979. [PMID: 30760526 DOI: 10.1074/jbc.ra118.007240] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/11/2019] [Indexed: 01/11/2023] Open
Abstract
The P-type ATPase protein family includes, in addition to ion pumps such as Ca2+-ATPase and Na+,K+-ATPase, also phospholipid flippases that transfer phospholipids between membrane leaflets. P-type ATPase ion pumps translocate their substrates occluded between helices in the center of the transmembrane part of the protein. The large size of the lipid substrate has stimulated speculation that flippases use a different transport mechanism. Information on the functional importance of the most centrally located helices M5 and M6 in the transmembrane domain of flippases has, however, been sparse. Using mutagenesis, we examined the entire M5-M6 region of the mammalian flippase ATP8A2 to elucidate its possible function in the lipid transport mechanism. This mutational screen yielded an informative map assigning important roles in the interaction with the lipid substrate to only a few M5-M6 residues. The M6 asparagine Asn-905 stood out as being essential for the lipid substrate-induced dephosphorylation. The mutants N905A/D/E/H/L/Q/R all displayed very low activities and a dramatic insensitivity to the lipid substrate. Strikingly, Asn-905 aligns with key ion-binding residues of P-type ATPase ion pumps, and N905D was recently identified as one of the mutations causing the neurological disorder cerebellar ataxia, mental retardation, and disequilibrium (CAMRQ) syndrome. Moreover, the effects of substitutions to the adjacent residue Val-906 (i.e. V906A/E/F/L/Q/S) suggest that the lipid substrate approaches Val-906 during the translocation. These results favor a flippase mechanism with strong resemblance to the ion pumps, despite a location of the translocation pathway in the periphery of the transmembrane part of the flippase protein.
Collapse
Affiliation(s)
- Stine A Mikkelsen
- From the Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Louise S Mogensen
- From the Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Bente Vilsen
- From the Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Robert S Molday
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Department of Ophthalmology and Visual Sciences, Centre for Macular Research, University of British Columbia, Vancouver, British Columbia V5Z 3N9, Canada
| | - Anna L Vestergaard
- From the Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jens Peter Andersen
- From the Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark.
| |
Collapse
|
49
|
Wang Y, Hirata T, Maeda Y, Murakami Y, Fujita M, Kinoshita T. Free, unlinked glycosylphosphatidylinositols on mammalian cell surfaces revisited. J Biol Chem 2019; 294:5038-5049. [PMID: 30728244 DOI: 10.1074/jbc.ra119.007472] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 01/30/2019] [Indexed: 12/17/2022] Open
Abstract
Glycosylphosphatidylinositols (GPIs) are linked to many cell-surface proteins, anchor these proteins in the membrane, and are well characterized. However, GPIs that exist in the free form on the mammalian cell surface remain largely unexplored. To investigate free GPIs in cultured cell lines and mouse tissues, here we used the T5-4E10 mAb (T5 mAb), which recognizes unlinked GPIs having an N-acetylgalactosamine (GalNAc) side chain linked to the first mannose at the nonreducing terminus. We detected free GPIs bearing the GalNAc side chain on the surface of Neuro2a and CHO, but not of HEK293, K562, and C2C12 cells. Furthermore, free GPIs were present in mouse pons, medulla oblongata, spinal cord, testis, epididymis, and kidney. Using a panel of Chinese hamster ovary cells defective in both GPI-transamidase and GPI remodeling pathway, we demonstrate that free GPIs follow the same structural remodeling pathway during passage from the endoplasmic reticulum to the plasma membrane as do protein-linked GPI. Specifically, free GPIs underwent post-GPI attachment to protein 1 (PGAP1)-mediated inositol deacylation, PGAP5-mediated removal of the ethanolamine phosphate from the second mannose, and PGAP3- and PGAP2-mediated fatty acid remodeling. Moreover, T5 mAb recognized free GPIs even if the inositol-linked acyl chain or ethanolamine-phosphate side chain linked to the second mannose is not removed. In contrast, addition of a fourth mannose by phosphatidylinositol glycan anchor biosynthesis class Z (PIGZ) inhibited T5 mAb-mediated detection of free GPIs. Our results indicate that free GPIs are normal components of the plasma membrane in some tissues and further characterize free GPIs in mammalian cells.
Collapse
Affiliation(s)
- Yicheng Wang
- From the Research Institute for Microbial Diseases and.,World Premier International (WPI) Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan and
| | | | - Yusuke Maeda
- From the Research Institute for Microbial Diseases and
| | - Yoshiko Murakami
- From the Research Institute for Microbial Diseases and.,World Premier International (WPI) Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan and
| | - Morihisa Fujita
- the Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Taroh Kinoshita
- From the Research Institute for Microbial Diseases and .,World Premier International (WPI) Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan and
| |
Collapse
|
50
|
Cecchetti C, Pyle E, Byrne B. Transporter oligomerisation: roles in structure and function. Biochem Soc Trans 2019; 47:433-40. [PMID: 30578344 DOI: 10.1042/BST20180316] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/18/2018] [Accepted: 11/15/2018] [Indexed: 01/27/2023]
Abstract
Oligomerisation is a key feature of integral membrane transporters with roles in structure, function and stability. In this review, we cover some very recent advances in our understanding of how oligomerisation affects these key transporter features, with emphasis on a few groups of transporters, including the nucleobase ascorbate transporters, neurotransmitter sodium symporters and major facilitator superfamily members.
Collapse
|