1
|
Pogozheva ID, Armstrong GA, Kong L, Hartnagel TJ, Carpino CA, Gee SE, Picarello DM, Rubin AS, Lee J, Park S, Lomize AL, Im W. Comparative Molecular Dynamics Simulation Studies of Realistic Eukaryotic, Prokaryotic, and Archaeal Membranes. J Chem Inf Model 2022; 62:1036-1051. [PMID: 35167752 DOI: 10.1021/acs.jcim.1c01514] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We present a comparative all-atom molecular dynamics simulation study of 18 biomembrane systems with lipid compositions corresponding to eukaryotic, bacterial, and archaebacterial membranes together with three single-component lipid bilayers. A total of 105 lipid types used in this study include diverse sterols and glycerol-based lipids with acyl chains of various lengths, unsaturation degrees, and branched or cyclic moieties. Our comparative analysis provides deeper insight into the influences of sterols and lipid unsaturation on the structural and mechanical properties of these biomembranes, including water permeation into the membrane hydrocarbon core. For sterol-containing membranes, sterol fraction is correlated with the membrane thickness, the area compressibility modulus, and lipid order but anticorrelated with the area per lipid and sterol tilt angles. Similarly, for all 18 biomembranes, lipid order is correlated with the membrane thickness and area compressibility modulus. Sterols and lipid unsaturation produce opposite effects on membrane thickness, but only sterols influence water permeation into the membrane. All membrane systems are accessible for public use in CHARMM-GUI Archive. They can be used as templates to expedite future modeling of realistic cell membranes with transmembrane and peripheral membrane proteins to study their structure, dynamics, molecular interactions, and function in a nativelike membrane environment.
Collapse
Affiliation(s)
- Irina D Pogozheva
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Grant A Armstrong
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Lingyang Kong
- Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Timothy J Hartnagel
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Carly A Carpino
- Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Stephen E Gee
- Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Danielle M Picarello
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Amanda S Rubin
- Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Jumin Lee
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Soohyung Park
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Andrei L Lomize
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Wonpil Im
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States.,Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States.,Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| |
Collapse
|
2
|
Weigle AT, Carr M, Shukla D. Impact of Increased Membrane Realism on Conformational Sampling of Proteins. J Chem Theory Comput 2021; 17:5342-5357. [PMID: 34339605 DOI: 10.1021/acs.jctc.1c00276] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The realism and accuracy of lipid bilayer simulations through molecular dynamics (MD) are heavily dependent on the lipid composition. While the field is pushing toward implementing more heterogeneous and realistic membrane compositions, a lack of high-resolution lipidomic data prevents some membrane protein systems from being modeled with the highest level of realism. Given the additional diversity of real-world cellular membranes and protein-lipid interactions, it is still not fully understood how altering membrane complexity affects modeled membrane protein functions or if it matters over long-timescale simulations. This is especially true for organisms whose membrane environments have little to no computational study, such as the plant plasma membrane. Tackling these issues in tandem, a generalized, realistic, and asymmetric plant plasma membrane with more than 10 different lipid species is constructed herein. Classical MD simulations of pure membrane constructs were performed to evaluate how altering the compositional complexity of the membrane impacted the plant membrane properties. The apo form of a plant sugar transporter, OsSWEET2b, was inserted into membrane models where lipid diversity was calculated in either a size-dependent or size-independent manner. An adaptive sampling simulation regime validated by Markov-state models was performed to capture the gating dynamics of OsSWEET2b in each of these membrane constructs. In comparison to previous OsSWEET2b simulations performed in a pure POPC bilayer, we confirm that simulations performed within a native-like membrane composition alter the stabilization of apo OsSWEET2b conformational states by ∼1 kcal/mol. The free-energy barriers of intermediate conformational states decrease when realistic membrane complexity is simplified, albeit roughly within sampling error, suggesting that protein-specific responses to membranes differ due to altered packing caused by compositional fluctuations. This work serves as a case study where a more realistic bilayer composition makes unbiased conformational sampling easier to achieve than with simplified bilayers.
Collapse
Affiliation(s)
- Austin T Weigle
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Matthew Carr
- Independent Software Development Provider310 East Marlette Avenue, Phoenix, Arizona 85012, United States
| | - Diwakar Shukla
- Department of Chemical & Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Center for Digital Agriculture, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,NIH Center for Macromolecular Modeling and Bioinformatics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
3
|
Acupoint Catgut Embedding Improves the Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome in Rats. BIOMED RESEARCH INTERNATIONAL 2020; 2020:2394734. [PMID: 32566670 PMCID: PMC7285251 DOI: 10.1155/2020/2394734] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 02/24/2020] [Accepted: 03/06/2020] [Indexed: 12/16/2022]
Abstract
Background This study investigated the potential therapeutic effects of acupoint catgut embedding (ACE) at ST36 and BL13 on lipopolysaccharide- (LPS-) induced acute respiratory distress syndrome (ARDS) in rats. Materials and Methods Male Sprague-Dawley rats were randomized into the normal saline (NS group with a sham procedure), lipopolysaccharide (LPS group with a sham procedure), and LPS plus ACE (LPS+ACE with ACE at bilateral BL13 and ST36 acupoints one day before LPS injection) groups. After intratracheal instillation of normal saline or LPS (0.5 mg/kg), all rats were subjected to mechanical ventilation for 4 h. Their blood gas was analyzed before and after lung injury, and their lung pressure-volumes were measured longitudinally. The levels of TNF-α, IL-6, IL-10, and phosphatidylcholine (PC) and total proteins (TP) in bronchial alveolar lavage fluid (BALF) were assessed. Their wet to dry lung weight ratios, histology, myeloperoxidase (MPO), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) levels were measured. Their lung aquaporin 1 (AQP1) and Occludin protein levels were analyzed. Results LPS administration significantly decreased the ratios of PaO2/FiO2 and pressure-volumes and induced lung inflammation and injury by increased concentrations of TNF-α, IL-6, IL-10, and TP in BALF and MPO and MDA in the lung but decreased PC in BALF and SOD activity in the lungs. LPS also reduced AQP1 and Occludin protein levels in the lung of rats. In contrast, ACE significantly mitigated the LPS-induced lung injury, inflammation, and oxidative stress and preserved the AQP1 and Occludin contents in the lung of rats. Conclusions ACE significantly improved respiratory function by mitigating inflammation and oxidative stress and preserving AQP1 and Occludin expression in the lung in a rat model of LPS-induced ARDS.
Collapse
|
4
|
Festa M, Lagostena L, Carpaneto A. Using the plant vacuole as a biological system to investigate the functional properties of exogenous channels and transporters. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:607-12. [PMID: 26431786 DOI: 10.1016/j.bbamem.2015.09.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 07/31/2015] [Accepted: 09/25/2015] [Indexed: 01/15/2023]
Abstract
Plant cells possess a large intracellular compartment that animal cells do not, the central vacuole, which has been investigated for a long time. The central vacuole can occupy up to 90% of the cellular volume and, differently from intracellular organelles from animal cells such as lysosomes or endosomes, it is easy to isolate. Because of its large dimension (up to 40 μm diameter) it can be successfully studied using the classical patch-clamp technique. Following the idea that the vacuolar membrane could be used as a convenient model to characterize the functional properties of channel-forming peptides, we verified that the phytotoxic lipodepsipeptide Syringopeptin 25A from Pseudomonas syringae pv syringae was able to form ionic pores in sugar beet vacuoles and we performed a detailed biophysical analysis. Recently, we extended the use of plant vacuoles to the expression and functional characterization of animal intracellular transporters, namely rat CLC-7, and channels, i.e. human TPC2. Since endo-lysosomal transporters and channels are still largely unexplored, principally because their intracellular localization renders them difficult to study, we believe that this novel approach will prove to be a powerful system for the investigation of the molecular mechanisms of exogenous transporters and channels. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale.
Collapse
Affiliation(s)
- M Festa
- Institute of Biophysics (IBF), CNR, Via De Marini 6, 16149 Genova, Italy
| | - L Lagostena
- Institute of Biophysics (IBF), CNR, Via De Marini 6, 16149 Genova, Italy
| | - A Carpaneto
- Institute of Biophysics (IBF), CNR, Via De Marini 6, 16149 Genova, Italy.
| |
Collapse
|
5
|
Zhang C, Hicks GR, Raikhel NV. Molecular Composition of Plant Vacuoles: Important but Less Understood Regulations and Roles of Tonoplast Lipids. PLANTS 2015; 4:320-33. [PMID: 27135331 PMCID: PMC4844321 DOI: 10.3390/plants4020320] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/21/2015] [Accepted: 06/03/2015] [Indexed: 11/16/2022]
Abstract
The vacuole is an essential organelle for plant growth and development. It is the location for the storage of nutrients; such as sugars and proteins; and other metabolic products. Understanding the mechanisms of vacuolar trafficking and molecule transport across the vacuolar membrane is of great importance in understanding basic plant development and cell biology and for crop quality improvement. Proteins play important roles in vacuolar trafficking; such proteins include Rab GTPase signaling proteins; cargo recognition receptors; and SNAREs (Soluble NSF Attachment Protein Receptors) that are involved in membrane fusion. Some vacuole membrane proteins also serve as the transporters or channels for transport across the tonoplast. Less understood but critical are the roles of lipids in vacuolar trafficking. In this review, we will first summarize molecular composition of plant vacuoles and we will then discuss our latest understanding on the role of lipids in plant vacuolar trafficking and a surprising connection to ribosome function through the study of ribosomal mutants.
Collapse
Affiliation(s)
- Chunhua Zhang
- Center for Plant Cell Biology & Department of Botany and Plant Sciences, University of California, 900 University Ave., Riverside, CA 92521, USA.
| | - Glenn R Hicks
- Center for Plant Cell Biology & Department of Botany and Plant Sciences, University of California, 900 University Ave., Riverside, CA 92521, USA.
| | - Natasha V Raikhel
- Center for Plant Cell Biology & Department of Botany and Plant Sciences, University of California, 900 University Ave., Riverside, CA 92521, USA.
| |
Collapse
|
6
|
Yoshida K, Ohnishi M, Fukao Y, Okazaki Y, Fujiwara M, Song C, Nakanishi Y, Saito K, Shimmen T, Suzaki T, Hayashi F, Fukaki H, Maeshima M, Mimura T. Studies on vacuolar membrane microdomains isolated from Arabidopsis suspension-cultured cells: local distribution of vacuolar membrane proteins. PLANT & CELL PHYSIOLOGY 2013; 54:1571-84. [PMID: 23903016 DOI: 10.1093/pcp/pct107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The local distribution of both the vacuolar-type proton ATPase (V-ATPase) and the vacuolar-type proton pyrophosphatase (V-PPase), the main vacuolar proton pumps, was investigated in intact vacuoles isolated from Arabidopsis suspension-cultured cells. Fluorescent immunostaining showed that V-PPase was distributed evenly on the vacuolar membrane (VM), but V-ATPase localized to specific regions of the VM. We hypothesize that there may be membrane microdomains on the VM. To confirm this hypothesis, we prepared detergent-resistant membranes (DRMs) from the VM in accordance with well established conventional methods. Analyses of fatty acid composition suggested that DRMs had more saturated fatty acids compared with the whole VM in phosphatidylcholine and phosphatidylethanolamine. In the proteomic analyses of both DRMs and detergent-soluble mebranes (DSMs), we confirmed the different local distributions of V-ATPase and V-PPase. The observations of DRMs with an electron microscope supported the existence of different areas on the VM. Moreover, it was observed using total internal reflection fluorescent microscopy (TIRFM) that proton pumps were frequently immobilized at specific sites on the VM. In the proteomic analyses, we also found that many other vacuolar membrane proteins are distributed differently in DRMs and DSMs. Based on the results of this study, we discuss the possibility that VM microdomains might contribute to vacuolar dynamics.
Collapse
Affiliation(s)
- Katsuhisa Yoshida
- Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
|
8
|
Jouhet J, Maréchal E, Block MA. Glycerolipid transfer for the building of membranes in plant cells. Prog Lipid Res 2007; 46:37-55. [PMID: 16970991 DOI: 10.1016/j.plipres.2006.06.002] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 06/14/2006] [Accepted: 06/20/2006] [Indexed: 01/05/2023]
Abstract
Membranes of plant organelles have specific glycerolipid compositions. Selective distribution of lipids at the levels of subcellular organelles, membrane leaflets and membrane domains reflects a complex and finely tuned lipid homeostasis. Glycerolipid neosynthesis occurs mainly in plastid envelope and endoplasmic reticulum membranes. Since most lipids are not only present in the membranes where they are synthesized, one cannot explain membrane specific lipid distribution by metabolic processes confined in each membrane compartment. In this review, we present our current understanding of glycerolipid trafficking in plant cells. We examine the potential mechanisms involved in lipid transport inside bilayers and from one membrane to another. We survey lipid transfers going through vesicular membrane flow and those dependent on lipid transfer proteins at membrane contact sites. By introducing recently described membrane lipid reorganization during phosphate deprivation and recent developments issued from mutant analyses, we detail the specific lipid transfers towards or outwards the chloroplast envelope.
Collapse
Affiliation(s)
- Juliette Jouhet
- Laboratoire de Physiologie, Cellulaire Végétale, UMR 5168 (CNRS/CEA/Université Joseph Fourier/INRA), DRDC/PCV, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble-cedex 9, France
| | | | | |
Collapse
|
9
|
Kuroyanagi M, Yamada K, Hatsugai N, Kondo M, Nishimura M, Hara-Nishimura I. Vacuolar Processing Enzyme Is Essential for Mycotoxin-induced Cell Death in Arabidopsis thaliana. J Biol Chem 2005; 280:32914-20. [PMID: 16043487 DOI: 10.1074/jbc.m504476200] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Some compatible pathogens secrete toxins to induce host cell death and promote their growth. The toxin-induced cell death is a pathogen strategy for infection. To clarify the executioner of the toxin-induced cell death, we examined a fungal toxin (fumonisin B1 (FB1))-induced cell death of Arabidopsis plants. FB1-induced cell death was accompanied with disruption of vacuolar membrane followed by lesion formation. The features of FB1-induced cell death were completely abolished in the Arabidopsis vacuolar processing enzyme (VPE)-null mutant, which lacks all four VPE genes of the genome. Interestingly, an inhibitor of caspase-1 abolished FB1-induced lesion formation, as did a VPE inhibitor. The VPE-null mutant had no detectable activities of caspase-1 or VPE in the FB1-treated leaves, although wild-type leaves had the caspase-1 and VPE activities, both of which were inhibited by a caspase-1 inhibitor. gammaVPE is the most essential among the four VPE homologues for FB1-induced cell death in Arabidopsis leaves. Recombinant gammaVPE recognized a VPE substrate with Km = 30.3 microm and a caspase-1 substrate with Km = 44.2 microm, which is comparable with the values for mammalian caspase-1. The gammaVPE precursor was self-catalytically converted into the mature form exhibiting caspase-1 activity. These in vivo and in vitro analyses demonstrate that gammaVPE is the proteinase that exhibits a caspase-1 activity. We show that VPE exhibiting a caspase-1 activity is a key molecule in toxin-induced cell death. Our findings suggest that a susceptible response of toxin-induced cell death is caused by the VPE-mediated vacuolar mechanism similar to a resistance response of hypersensitive cell death (Hatsugai, N., Kuroyanagi, M., Yamada, K., Meshi, T., Tsuda, S., Kondo, M., Nishimura, M., and Hara-Nishimura, I. (2004) Science 305, 855-858).
Collapse
Affiliation(s)
- Miwa Kuroyanagi
- Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | | | | | | | | | | |
Collapse
|
10
|
Lynch DV, Dunn TM. An introduction to plant sphingolipids and a review of recent advances in understanding their metabolism and function. THE NEW PHYTOLOGIST 2004; 161:677-702. [PMID: 33873728 DOI: 10.1111/j.1469-8137.2004.00992.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Sphingolipids are ubiquitous constituents of eukaryotic cells, and have been intensively investigated in mammals and yeast for decades. Aspects of sphingolipid biochemistry in plants have been explored only recently. To date, progress has been made in determining the structure and occurrence of sphingolipids in plant tissues; in characterizing the enzymatic steps involved in production and turnover of sphingolipids (and, in some cases, the genes encoding the relevant enzymes); and in identifying a variety of biological functions for sphingolipids in plants. Given that these efforts are far from complete and much remains to be learned, this review represents a status report on the burgeoning field of plant sphingolipid biochemistry. Contents Summary 677 I. Introduction 678 II. Plant sphingolipid structure 678 III. Sphingolipid metabolism in plants 683 IV. Sphingolipid functions in plants 693 V. Conclusions 696 Acknowledgements 696 References 696.
Collapse
Affiliation(s)
- Daniel V Lynch
- Department of Biology, Williams College, Williamstown, MA 01267, USA
| | - Teresa M Dunn
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| |
Collapse
|
11
|
Yamaguchi M, Kasamo K. Modulation of proton pumping across proteoliposome membranes reconstituted with tonoplast H(+)-ATPase from cultured rice (Oryza sativa L. var. Boro) cells by acyl steryl glucoside and steryl glucoside. PLANT & CELL PHYSIOLOGY 2002; 43:816-22. [PMID: 12154145 DOI: 10.1093/pcp/pcf096] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Tonoplast H(+)-ATPase purified from cultured rice cells (Oryza sativa L. var. Boro) was reconstituted into asolectin liposomes containing steryl glucoside (SG) or acyl steryl glucoside (ASG), and the effects of SG and ASG on proton pumping, ATP-hydrolysis activity and proton permeability of the proteoliposome membranes were investigated. In the proteoliposomes containing 10 mol% SG, proton pumping and ATP-hydrolysis activity were increased to around 140% of those in SG-free proteoliposomes. In the proteoliposomes containing ASG, proton pumping and ATP-hydrolysis activity were decreased to one-tenth of those in ASG-free proteoliposomes at 15 mol% ASG; however, activity increased again slightly in the range between 20 and 40 mol% ASG. The change in proton pumping across the proteoliposome membrane is not due to a change of proteoliposome size nor to the location of the catalytic site of the tonoplast H(+)-ATPase in the proteoliposomes. SG and ASG also reduced the passive proton permeability of the proteoliposomes. These results show that SG and ASG modulate proton pumping across the tonoplast toward stimulation and depression, respectively, and they reduce the passive proton permeability of the tonoplast.
Collapse
Affiliation(s)
- Mineo Yamaguchi
- Research Institute for Bioresources, Okayama University, Kurashiki, Okayama, 710-0046 Japan
| | | |
Collapse
|
12
|
Maeshima M. TONOPLAST TRANSPORTERS: Organization and Function. ANNUAL REVIEW OF PLANT PHYSIOLOGY AND PLANT MOLECULAR BIOLOGY 2001; 52:469-497. [PMID: 11337406 DOI: 10.1146/annurev.arplant.52.1.469] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Regulation of the contents and volume of vacuoles in plant cells depends on the coordinated activities of transporters and channels located in the tonoplast (vacuolar membrane). The three major components of the tonoplast are two proton pumps, the vacuolar H+-ATPase (V-ATPase) and H+-pyrophosphatase (V-PPase), and aquaporins. The tertiary structure of the V-ATPase complex and properties of its subunits have been characterized by biochemical and genetic techniques. These studies and a comparison with the F-type ATPase have enabled estimation of the dynamics of V-ATPase activity during catalysis. V-PPase, a simple proton pump, has been identified and cloned from various plant species and other organisms, such as algae and phototrophic bacteria, and functional motifs of the enzyme have been determined. Aquaporin, serving as the water channel, is the most abundant protein in the tonoplast in most plants. A common molecular architecture of aquaporins in mammals and plants has been determined by two-dimensional crystallographic analysis. Furthermore, recent molecular biological studies have revealed several other types of tonoplast transporters, such as the Ca2+-ATPase, Ca2+/H+ antiporter and Na+/H+ antiporter. Many other transporters and channels in the tonoplast remain to be identified; their activities have already been detected. This review presents an overview of the field and discusses recent findings on the tonoplast protein components that have been identified and their physiological consequences.
Collapse
Affiliation(s)
- Masayoshi Maeshima
- Laboratory of Biochemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan; e-mail:
| |
Collapse
|
13
|
Yamaguchi M, Kasamo K. Modulation in the activity of purified tonoplast H+-ATPase by tonoplast glycolipids prepared from cultured rice (Oryza sativa L. var. Boro) cells. PLANT & CELL PHYSIOLOGY 2001; 42:516-23. [PMID: 11382818 DOI: 10.1093/pcp/pce064] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Glycolipids, phospholipids, and neutral lipids were extracted from the tonoplast fraction of cultured rice cells (Oryza sativa L. var. Boro). Acyl steryl glucoside (ASG) and glucocerebroside (GlcCer) were also prepared from this fraction. We determined the effects of these tonoplast lipids on the activity of H+-ATPase which was delipidated and purified from the tonoplast fraction. Exogenously added tonoplast phospholipids stimulated the activity of purified tonoplast H+-ATPase, but tonoplast glycolipids did not. When tonoplast glycolipids or tonoplast ASG was added in the presence of tonoplast phospholipids, they decreased the phospholipid-induced activation of the tonoplast H+-ATPase; tonoplast GlcCer only caused a small decrease. Steryl glucoside (SG) did not cause any decrease in this activation. Phospholipids, ASG, and GlcCer made up 35 mol%, 20 mol% and 7 mol% of the total lipids of the tonoplast fraction of cultured rice cells, respectively, and these glycolipid levels were enough to depress the phospholipid-induced activation of the tonoplast H+-ATPASE: These results revealed that H+-ATPase activity in the tonoplast may be modulated toward activation and depression by tonoplast phospholipids and glycolipids, respectively. The acylation of SG would be responsible for the depression in the phospholipid-induced H+-ATPase activity.
Collapse
Affiliation(s)
- M Yamaguchi
- Research Institute for Bioresources, Okayama University, Kurashiki, Okayama, 710-0046 Japan
| | | |
Collapse
|
14
|
Kasamo K, Yamaguchi M, Nakamura Y. Mechanism of the chilling-induced decrease in proton pumping across the tonoplast of rice cells. PLANT & CELL PHYSIOLOGY 2000; 41:840-9. [PMID: 10965940 DOI: 10.1093/pcp/pcd002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The ATP-generated proton pumping across tonoplast vesicles from chilling-sensitive Boro rice (Oryza sativa L. var. Boro) cultured cells was markedly decreased by chilling at 5 degrees C for 3 d. The membrane fluidity of core hydrophobic and surface hydrophilic regions of the lipid bilayer was measured by steady-state fluorescence depolarization of 1,6-diphenyl-1,3,5-hexatriene and trimethylammonium 1,6-diphenyl-1,3,5-hexatriene and by electron spin resonance spectroscopy of 16- and 5-doxyl stearic acid, respectively. The fluidity of the surface region of the lipid bilayer of the tonoplast vesicles decreased by chilling. The fluidity of the surface region of the liposomes and the proton pumping across the reconstituted proteoliposomes with tonoplast H+-ATPase decreased with increasing content of the glycolipids. The proton pumping across chimera proteoliposomes was reduced by chilling only when it was reconstituted in the presence of tonoplast glycolipids from chilled Boro cells. These data suggest that the reduction in ATP-generated proton pumping across the tonoplast by chilling is due to the decrease in the fluidity of the surface region of the lipid bilayer of the tonoplast, which is caused by the changes in glycolipids.
Collapse
Affiliation(s)
- K Kasamo
- Research Institute for Bioresources, Okayama University, Kurashiki, Japan.
| | | | | |
Collapse
|
15
|
Affiliation(s)
- D V Lynch
- Department of Biology, Williams College, Williamstown, Massachusetts 01267, USA
| |
Collapse
|
16
|
Moreau P, Bessoule JJ, Mongrand S, Testet E, Vincent P, Cassagne C. Lipid trafficking in plant cells. Prog Lipid Res 1998; 37:371-91. [PMID: 10209654 DOI: 10.1016/s0163-7827(98)00016-2] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- P Moreau
- Laboratoire de Biogenèse Membranaire, UMR 5544-CNRS, Université Victory Segalen Bordeaux, France.
| | | | | | | | | | | |
Collapse
|
17
|
Lynch DV, Criss AK, Lehoczky JL, Bui VT. Ceramide glucosylation in bean hypocotyl microsomes: evidence that steryl glucoside serves as glucose donor. Arch Biochem Biophys 1997; 340:311-6. [PMID: 9143336 DOI: 10.1006/abbi.1997.9928] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The formation of glucosylceramide, the predominant sphingolipid in plant tissues, was examined in microsomes from wax bean hypocotyls. Membranes were incubated with UDP-[14C]glucose in an assay mixture. The lipid extracts obtained from the assays were separated by thin-layer chromatography, and the radioactivity incorporated into glucosylceramide, steryl glucoside, and acylated steryl glucoside was determined. Although the formation of glucosylceramide was detected and characterized, several lines of evidence contradicted the assumption that UDP-glucose is the immediate glucose donor for glucosylceramide formation in plants: PDMP (DL-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol), an inhibitor of ceramide glucosyltransferase in animal tissues, did not inhibit glucosylceramide formation in bean microsomes. Addition of UDP-glucose pyrophosphorylase during the assay to degrade UDP-[14C]glucose blocked the further production of labeled steryl glucoside, but did not prevent the continued formation of labeled glucosylceramide. Omitting UDP-[14C]glucose and including steryl [14C]glucoside in the assay resulted in the formation of labeled glucosylceramide. Collectively, these results suggest that glucosylceramide formation in plants does not utilize UDP-glucose as the immediate glucose donor, as has been demonstrated for the reaction in animal tissues, and that steryl glucoside serves as glucose donor for ceramide formation. This study, the first to examine glucosylceramide formation in plants, provides evidence for a novel enzymatic reaction in sphingolipid synthesis as well as a new, metabolic role for steryl glucoside in plant tissues.
Collapse
Affiliation(s)
- D V Lynch
- Department of Biology, Williams College, Williamstown, Massachusetts 01267, USA
| | | | | | | |
Collapse
|
18
|
Tavernier E, Pugin A. Phospholipase activities associated with the tonoplast from Acer pseudoplatanus cells: identification of a phospholipase A1 activity. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1233:118-22. [PMID: 7865536 DOI: 10.1016/0005-2736(94)00273-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The study of phospholipase activities associated with the tonoplast of Acer pseudoplatanus was performed in vitro with sn-2-[14C]acylphosphatidylcholine (PC) as a substrate. The hydrolysis of radiolabelled PC into [14C]phosphatidic acid and [14C]lyso-PC demonstrated the presence of phospholipase D and A1 activities, respectively, associated with the tonoplast of Acer pseudoplatanus. The vacuolar sap did not show any significant phospholipase activity. In a second step, the properties of the phospholipase A1 activity was studied using tonoplast endogenous PC labelled in vivo with [14C]choline as a substrate. The phospholipase A1 showed an optimal activity at pH about 6-6.5, did not necessarily require divalent cations, but was stimulated by Mg2+ and particularly by Ca2+. This work presents the first evidence for the presence of phospholipases A1 in plant cells.
Collapse
Affiliation(s)
- E Tavernier
- Laboratoire de Biochimie et Biologie Moleculaire, UFR Sciences et Techniques, Besançon, France
| | | |
Collapse
|
19
|
Tavernier E, Pugin A. Transbilayer distribution of phosphatidylcholine and phosphatidylethanolamine in the vacuolar membrane of Acer pseudoplatanus cells. Biochimie 1995; 77:174-81. [PMID: 7647109 DOI: 10.1016/0300-9084(96)88122-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The distribution of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) among the outer and inner monolayers of the vacuolar membrane of Acer pseudoplatanus was investigated using isolated vacuoles, chemical labelling agents (trinitrobenzene-sulfonate and fluorescamine), phospholipase A2 from bee venom, phospholipase C and phospholipase D. Treatments were performed with intact or sonicated vacuoles. Analysis of the transbilayer distribution of PC and PE in the vacuolar membrane of Acer was limited by phospholipid fractions which were inaccessible to the probes. Lipid-protein interactions and modification of the surface charge and surface pressure in the membrane layers during treatments may obviously exert a strong influence on labelling or hydrolysis of membrane phospholipids. However, simultaneous treatments carried out with phospholipase A2 and phospholipase C show that PE is approximately 20% more abundant in the outer monolayer than in the inner monolayer and PC is equally distributed between both leaflets of tonoplast. Compared to the phospholipids asymmetrical distribution observed in plasma membrane of erythrocyte, the vacuolar membrane of Acer is not characterized by a marked asymmetrical distribution of its major phospholipids.
Collapse
Affiliation(s)
- E Tavernier
- Laboratoire de Biochimie et Biologie Moléculaire, UFR Sciences et Techniques, Besançon, France
| | | |
Collapse
|