1
|
Patrick J, Alija MG, Liebau J, Pettersson P, Metola A, Mäler L. Dilute Bicelles for Glycosyltransferase Studies, Novel Bicelles with Phosphatidylinositol. J Phys Chem B 2022; 126:5655-5666. [PMID: 35880265 PMCID: PMC9358657 DOI: 10.1021/acs.jpcb.2c02327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Solution-state NMR can be used to study protein-lipid interactions, in particular, the effect that proteins have on lipids. One drawback is that only small assemblies can be studied, and therefore, fast-tumbling bicelles are commonly used. Bicelles contain a lipid bilayer that is solubilized by detergents. A complication is that they are only stable at high concentrations, exceeding the CMC of the detergent. This issue has previously been addressed by introducing a detergent (Cyclosfos-6) with a substantially lower CMC. Here, we developed a set of bicelles using this detergent for studies of membrane-associated mycobacterial proteins, for example, PimA, a key enzyme for bacterial growth. To mimic the lipid composition of mycobacterial membranes, PI, PG, and PC lipids were used. Diffusion NMR was used to characterize the bicelles, and spin relaxation was used to measure the dynamic properties of the lipids. The results suggest that bicelles are formed, although they are smaller than "conventional" bicelles. Moreover, we studied the effect of MTSL-labeled PimA on bicelles containing PI and PC. The paramagnetic label was shown to have a shallow location in the bicelle, affecting the glycerol backbone of the lipids. We foresee that these bicelles will be useful for detailed studies of protein-lipid interactions.
Collapse
Affiliation(s)
- Joan Patrick
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Mikel García Alija
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Jobst Liebau
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Pontus Pettersson
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ane Metola
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| |
Collapse
|
2
|
Royes J, Biou V, Dautin N, Tribet C, Miroux B. Inducible intracellular membranes: molecular aspects and emerging applications. Microb Cell Fact 2020; 19:176. [PMID: 32887610 PMCID: PMC7650269 DOI: 10.1186/s12934-020-01433-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 08/27/2020] [Indexed: 02/08/2023] Open
Abstract
Membrane remodeling and phospholipid biosynthesis are normally tightly regulated to maintain the shape and function of cells. Indeed, different physiological mechanisms ensure a precise coordination between de novo phospholipid biosynthesis and modulation of membrane morphology. Interestingly, the overproduction of certain membrane proteins hijack these regulation networks, leading to the formation of impressive intracellular membrane structures in both prokaryotic and eukaryotic cells. The proteins triggering an abnormal accumulation of membrane structures inside the cells (or membrane proliferation) share two major common features: (1) they promote the formation of highly curved membrane domains and (2) they lead to an enrichment in anionic, cone-shaped phospholipids (cardiolipin or phosphatidic acid) in the newly formed membranes. Taking into account the available examples of membrane proliferation upon protein overproduction, together with the latest biochemical, biophysical and structural data, we explore the relationship between protein synthesis and membrane biogenesis. We propose a mechanism for the formation of these non-physiological intracellular membranes that shares similarities with natural inner membrane structures found in α-proteobacteria, mitochondria and some viruses-infected cells, pointing towards a conserved feature through evolution. We hope that the information discussed in this review will give a better grasp of the biophysical mechanisms behind physiological and induced intracellular membrane proliferation, and inspire new applications, either for academia (high-yield membrane protein production and nanovesicle production) or industry (biofuel production and vaccine preparation).
Collapse
Affiliation(s)
- Jorge Royes
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université de Paris, LBPC-PM, CNRS, UMR7099, 75005, Paris, France. .,Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le Développement de la Recherche Scientifique, 75005, Paris, France. .,Département de Chimie, École Normale Supérieure, PASTEUR, PSL University, CNRS, Sorbonne Université, 24 Rue Lhomond, 75005, Paris, France.
| | - Valérie Biou
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université de Paris, LBPC-PM, CNRS, UMR7099, 75005, Paris, France.,Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le Développement de la Recherche Scientifique, 75005, Paris, France
| | - Nathalie Dautin
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université de Paris, LBPC-PM, CNRS, UMR7099, 75005, Paris, France.,Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le Développement de la Recherche Scientifique, 75005, Paris, France
| | - Christophe Tribet
- Département de Chimie, École Normale Supérieure, PASTEUR, PSL University, CNRS, Sorbonne Université, 24 Rue Lhomond, 75005, Paris, France
| | - Bruno Miroux
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université de Paris, LBPC-PM, CNRS, UMR7099, 75005, Paris, France. .,Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le Développement de la Recherche Scientifique, 75005, Paris, France.
| |
Collapse
|
3
|
Zhukovsky MA, Filograna A, Luini A, Corda D, Valente C. Protein Amphipathic Helix Insertion: A Mechanism to Induce Membrane Fission. Front Cell Dev Biol 2019; 7:291. [PMID: 31921835 PMCID: PMC6914677 DOI: 10.3389/fcell.2019.00291] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 11/06/2019] [Indexed: 12/19/2022] Open
Abstract
One of the fundamental features of biomembranes is the ability to fuse or to separate. These processes called respectively membrane fusion and fission are central in the homeostasis of events such as those related to intracellular membrane traffic. Proteins that contain amphipathic helices (AHs) were suggested to mediate membrane fission via shallow insertion of these helices into the lipid bilayer. Here we analyze the AH-containing proteins that have been identified as essential for membrane fission and categorize them in few subfamilies, including small GTPases, Atg proteins, and proteins containing either the ENTH/ANTH- or the BAR-domain. AH-containing fission-inducing proteins may require cofactors such as additional proteins (e.g., lipid-modifying enzymes), or lipids (e.g., phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2], phosphatidic acid [PA], or cardiolipin). Both PA and cardiolipin possess a cone shape and a negative charge (-2) that favor the recruitment of the AHs of fission-inducing proteins. Instead, PtdIns(4,5)P2 is characterized by an high negative charge able to recruit basic residues of the AHs of fission-inducing proteins. Here we propose that the AHs of fission-inducing proteins contain sequence motifs that bind lipid cofactors; accordingly (K/R/H)(K/R/H)xx(K/R/H) is a PtdIns(4,5)P2-binding motif, (K/R)x6(F/Y) is a cardiolipin-binding motif, whereas KxK is a PA-binding motif. Following our analysis, we show that the AHs of many fission-inducing proteins possess five properties: (a) at least three basic residues on the hydrophilic side, (b) ability to oligomerize, (c) optimal (shallow) depth of insertion into the membrane, (d) positive cooperativity in membrane curvature generation, and (e) specific interaction with one of the lipids mentioned above. These lipid cofactors favor correct conformation, oligomeric state and optimal insertion depth. The most abundant lipid in a given organelle possessing high negative charge (more negative than -1) is usually the lipid cofactor in the fission event. Interestingly, naturally occurring mutations have been reported in AH-containing fission-inducing proteins and related to diseases such as centronuclear myopathy (amphiphysin 2), Charcot-Marie-Tooth disease (GDAP1), Parkinson's disease (α-synuclein). These findings add to the interest of the membrane fission process whose complete understanding will be instrumental for the elucidation of the pathogenesis of diseases involving mutations in the protein AHs.
Collapse
Affiliation(s)
- Mikhail A. Zhukovsky
- Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | | | | | - Daniela Corda
- Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Carmen Valente
- Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| |
Collapse
|
4
|
Jamin N, Garrigos M, Jaxel C, Frelet-Barrand A, Orlowski S. Ectopic Neo-Formed Intracellular Membranes in Escherichia coli: A Response to Membrane Protein-Induced Stress Involving Membrane Curvature and Domains. Biomolecules 2018; 8:biom8030088. [PMID: 30181516 PMCID: PMC6163855 DOI: 10.3390/biom8030088] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/31/2018] [Accepted: 08/31/2018] [Indexed: 11/16/2022] Open
Abstract
Bacterial cytoplasmic membrane stress induced by the overexpression of membrane proteins at high levels can lead to formation of ectopic intracellular membranes. In this review, we report the various observations of such membranes in Escherichia coli, compare their morphological and biochemical characterizations, and we analyze the underlying molecular processes leading to their formation. Actually, these membranes display either vesicular or tubular structures, are separated or connected to the cytoplasmic membrane, present mono- or polydispersed sizes and shapes, and possess ordered or disordered arrangements. Moreover, their composition differs from that of the cytoplasmic membrane, with high amounts of the overexpressed membrane protein and altered lipid-to-protein ratio and cardiolipin content. These data reveal the importance of membrane domains, based on local specific lipid⁻protein and protein⁻protein interactions, with both being crucial for local membrane curvature generation, and they highlight the strong influence of protein structure. Indeed, whether the cylindrically or spherically curvature-active proteins are actively curvogenic or passively curvophilic, the underlying molecular scenarios are different and can be correlated with the morphological features of the neo-formed internal membranes. Delineating these molecular mechanisms is highly desirable for a better understanding of protein⁻lipid interactions within membrane domains, and for optimization of high-level membrane protein production in E. coli.
Collapse
Affiliation(s)
- Nadège Jamin
- Institute for Integrative Biology of the Cell (I2BC), CEA/Institut des Sciences du Vivant Fréderic-Joliot/SB2SM, CNRS UMR 9198, Université Paris-Sud, Université Paris-Saclay, 91191 Gif sur Yvette CEDEX, France.
| | - Manuel Garrigos
- Institute for Integrative Biology of the Cell (I2BC), CEA/Institut des Sciences du Vivant Fréderic-Joliot/SB2SM, CNRS UMR 9198, Université Paris-Sud, Université Paris-Saclay, 91191 Gif sur Yvette CEDEX, France.
| | - Christine Jaxel
- Institute for Integrative Biology of the Cell (I2BC), CEA/Institut des Sciences du Vivant Fréderic-Joliot/SB2SM, CNRS UMR 9198, Université Paris-Sud, Université Paris-Saclay, 91191 Gif sur Yvette CEDEX, France.
| | - Annie Frelet-Barrand
- Institut FEMTO-ST, UMR CNRS 6174, Université Bourgogne Franche-Comté, 15B avenue des Montboucons, 25030 Besançon CEDEX, France.
| | - Stéphane Orlowski
- Institute for Integrative Biology of the Cell (I2BC), CEA/Institut des Sciences du Vivant Fréderic-Joliot/SB2SM, CNRS UMR 9198, Université Paris-Sud, Université Paris-Saclay, 91191 Gif sur Yvette CEDEX, France.
| |
Collapse
|
5
|
Liebau J, Ye W, Mäler L. Characterization of fast-tumbling isotropic bicelles by PFG diffusion NMR. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:395-404. [PMID: 26662467 DOI: 10.1002/mrc.4399] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 11/12/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
Small isotropic bicelles are versatile membrane mimetics, which, in contrast to micelles, provide a lipid bilayer and are at the same time suitable for solution-state NMR studies. The lipid composition of the bilayer is flexible allowing for incorporation of various head groups and acyl chain types. In bicelles, lipids are solubilized by detergents, which are localized in the rim of the disk-shaped lipid bilayer. Bicelles have been characterized by a broad array of biophysical methods, pulsed-field gradient NMR (PFG NMR) being one of them. PFG NMR can readily be used to measure diffusion coefficients of macromolecules. It is thus employed to characterize bicelle size and morphology. Even more importantly, PFG NMR can be used to study the degree of protein association to membranes. Here, we present the advances that have been made in producing small, fast-tumbling isotropic bicelles from a variety of lipids and detergents, together with insights on the morphology of such mixtures gained from PFG NMR. Furthermore, we review approaches to study protein-membrane interaction by PFG NMR. Copyright © 2015 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Jobst Liebau
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Weihua Ye
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| |
Collapse
|
6
|
Fast-tumbling bicelles constructed from native Escherichia coli lipids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2097-2105. [DOI: 10.1016/j.bbamem.2016.06.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 11/20/2022]
|
7
|
Liebau J, Pettersson P, Szpryngiel S, Mäler L. Membrane Interaction of the Glycosyltransferase WaaG. Biophys J 2016; 109:552-63. [PMID: 26244737 DOI: 10.1016/j.bpj.2015.06.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 06/17/2015] [Accepted: 06/19/2015] [Indexed: 11/30/2022] Open
Abstract
The glycosyltransferase WaaG is involved in the synthesis of lipopolysaccharides that constitute the outer leaflet of the outer membrane in Gram-negative bacteria such as Escherichia coli. WaaG has been identified as a potential antibiotic target, and inhibitor scaffolds have previously been investigated. WaaG is located at the cytosolic side of the inner membrane, where the enzyme catalyzes the transfer of the first outer-core glucose to the inner core of nascent lipopolysaccharides. Here, we characterized the binding of WaaG to membrane models designed to mimic the inner membrane of E. coli. Based on the crystal structure, we identified an exposed and largely α-helical 30-residue sequence, with a net positive charge and several aromatic amino acids, as a putative membrane-interacting region of WaaG (MIR-WaaG). We studied the peptide corresponding to this sequence, along with its bilayer interactions, using circular dichroism, fluorescence quenching, fluorescence anisotropy, and NMR. In the presence of dodecylphosphocholine, MIR-WaaG was observed to adopt a three-dimensional structure remarkably similar to the segment in the crystal structure. We found that the membrane interaction of WaaG is conferred at least in part by MIR-WaaG and that electrostatic interactions play a key role in binding. Moreover, we propose a mechanism of anchoring WaaG to the inner membrane of E. coli, where the central part of MIR-WaaG inserts into one leaflet of the bilayer. In this model, electrostatic interactions as well as surface-exposed Tyr residues bind WaaG to the membrane.
Collapse
Affiliation(s)
- Jobst Liebau
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Pontus Pettersson
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Scarlett Szpryngiel
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
| |
Collapse
|
8
|
Keller R, Ariöz C, Hansmeier N, Stenberg-Bruzell F, Burstedt M, Vikström D, Kelly A, Wieslander Å, Daley DO, Hunke S. The Escherichia coli Envelope Stress Sensor CpxA Responds to Changes in Lipid Bilayer Properties. Biochemistry 2015; 54:3670-6. [PMID: 25993101 DOI: 10.1021/acs.biochem.5b00242] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Cpx stress response system is induced by various environmental and cellular stimuli. It is also activated in Escherichia coli strains lacking the major phospholipid, phosphatidylethanolamine (PE). However, it is not known whether CpxA directly senses changes in the lipid bilayer or the presence of misfolded proteins due to the lack of PE in their membranes. To address this question, we used an in vitro reconstitution system and vesicles with different lipid compositions to track modulations in the activity of CpxA in different lipid bilayers. Moreover, the Cpx response was validated in vivo by monitoring expression of a PcpxP-gfp reporter in lipid-engineered strains of E. coli. Our combined data indicate that CpxA responds specifically to different lipid compositions.
Collapse
Affiliation(s)
- Rebecca Keller
- †Department of Pharmacy and Biochemistry, Johannes Gutenberg-University, D-55128 Mainz, Germany
| | - Candan Ariöz
- ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Nicole Hansmeier
- §Department of Microbiology, University of Osnabrück, D-49076 Osnabrück, Germany
| | - Filippa Stenberg-Bruzell
- ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Malin Burstedt
- ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - David Vikström
- ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Amelie Kelly
- ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Åke Wieslander
- ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Daniel O Daley
- ‡Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Sabine Hunke
- ∥Molecular Microbiology, University of Osnabrück, D-49076 Osnabrück, Germany
| |
Collapse
|
9
|
Bodor A, Kövér KE, Mäler L. Membrane interactions in small fast-tumbling bicelles as studied by 31P NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:760-6. [PMID: 25497765 DOI: 10.1016/j.bbamem.2014.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 11/11/2014] [Accepted: 12/01/2014] [Indexed: 01/02/2023]
Abstract
Small fast-tumbling bicelles are ideal for studies of membrane interactions at molecular level; they allow analysis of lipid properties using solution-state NMR. In the present study we used 31P NMR relaxation to obtain detailed information on lipid head-group dynamics. We explored the effect of two topologically different membrane-interacting peptides on bicelles containing either dimyristoylphosphocholine (DMPC), or a mixture of DMPC and dimyristoylphosphoglycerol (DMPG), and dihexanoylphosphocholine (DHPC). KALP21 is a model transmembrane peptide, designed to span a DMPC bilayer and dynorphin B is a membrane surface active neuropeptide. KALP21 causes significant increase in bicelle size, as evidenced by both dynamic light scattering and 31P T2 relaxation measurements. The effect of dynorphin B on bicelle size is more modest, although significant effects on T2 relaxation are observed at higher temperatures. A comparison of 31P T1 values for the lipids with and without the peptides showed that dynorphin B has a greater effect on lipid head-group dynamics than KALP21, especially at elevated temperatures. From the field-dependence of T1 relaxation data, a correlation time describing the overall lipid motion was derived. Results indicate that the positively charged dynorphin B decreases the mobility of the lipid molecules--in particular for the negatively charged DMPG--while KALP21 has a more modest influence. Our results demonstrate that while a transmembrane peptide has severe effects on overall bilayer properties, the surface bound peptide has a more dramatic effect in reducing lipid head-group mobility. These observations may be of general importance for understanding peptide-membrane interactions.
Collapse
Affiliation(s)
- Andrea Bodor
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, Eötvös Loránd University, H-1117 Budapest, Hungary.
| | - Katalin E Kövér
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4032 Debrecen, Hungary
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm Sweden.
| |
Collapse
|
10
|
Jovanovic G, Mehta P, Ying L, Buck M. Anionic lipids and the cytoskeletal proteins MreB and RodZ define the spatio-temporal distribution and function of membrane stress controller PspA in Escherichia coli. Microbiology (Reading) 2014; 160:2374-2386. [DOI: 10.1099/mic.0.078527-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
All cell types must maintain the integrity of their membranes. The conserved bacterial membrane-associated protein PspA is a major effector acting upon extracytoplasmic stress and is implicated in protection of the inner membrane of pathogens, formation of biofilms and multi-drug-resistant persister cells. PspA and its homologues in Gram-positive bacteria and archaea protect the cell envelope whilst also supporting thylakoid biogenesis in cyanobacteria and higher plants. In enterobacteria, PspA is a dual function protein negatively regulating the Psp system in the absence of stress and acting as an effector of membrane integrity upon stress. We show that in Escherichia coli the low-order oligomeric PspA regulatory complex associates with cardiolipin-rich, curved polar inner membrane regions. There, cardiolipin and the flotillin 1 homologue YqiK support the PspBC sensors in transducing a membrane stress signal to the PspA-PspF inhibitory complex. After stress perception, PspA high-order oligomeric effector complexes initially assemble in polar membrane regions. Subsequently, the discrete spatial distribution and dynamics of PspA effector(s) in lateral membrane regions depend on the actin homologue MreB and the peptidoglycan machinery protein RodZ. The consequences of loss of cytoplasmic membrane anionic lipids, MreB, RodZ and/or YqiK suggest that the mode of action of the PspA effector is closely associated with cell envelope organization.
Collapse
Affiliation(s)
- Goran Jovanovic
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Parul Mehta
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Liming Ying
- National Heart and Lung Institute, Imperial College London, London SW7 2AZ, UK
| | - Martin Buck
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| |
Collapse
|
11
|
Ge C, Gómez-Llobregat J, Skwark MJ, Ruysschaert JM, Wieslander A, Lindén M. Membrane remodeling capacity of a vesicle-inducing glycosyltransferase. FEBS J 2014; 281:3667-84. [PMID: 24961908 DOI: 10.1111/febs.12889] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 05/21/2014] [Accepted: 06/19/2014] [Indexed: 11/28/2022]
Abstract
Intracellular vesicles are abundant in eukaryotic cells but absent in the Gram-negative bacterium Escherichia coli. However, strong overexpression of a monotopic glycolipid-synthesizing enzyme, monoglucosyldiacylglycerol synthase from Acholeplasma laidlawii (alMGS), leads to massive formation of vesicles in the cytoplasm of E. coli. More importantly, alMGS provides a model system for the regulation of membrane properties by membrane-bound enzymes, which is critical for maintaining cellular integrity. Both phenomena depend on how alMGS binds to cell membranes, which is not well understood. Here, we carry out a comprehensive investigation of the membrane binding of alMGS by combining bioinformatics methods with extensive biochemical studies, structural modeling and molecular dynamics simulations. We find that alMGS binds to the membrane in a fairly upright manner, mainly by residues in the N-terminal domain, and in a way that induces local enrichment of anionic lipids and a local curvature deformation. Furthermore, several alMGS variants resulting from substitution of residues in the membrane anchoring segment are still able to generate vesicles, regardless of enzymatic activity. These results clarify earlier theories about the driving forces for vesicle formation, and shed new light on the membrane binding properties and enzymatic mechanism of alMGS and related monotopic GT-B fold glycosyltransferases.
Collapse
Affiliation(s)
- Changrong Ge
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, Sweden; Laboratory for the Structure and Function of Biological Membranes, Center for Structural Biology and Bioinformatics, Université Libre de Bruxelles, Belgium; Medical Inflammation Research, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | | | | | | | | | | |
Collapse
|
12
|
Ariöz C, Götzke H, Lindholm L, Eriksson J, Edwards K, Daley DO, Barth A, Wieslander A. Heterologous overexpression of a monotopic glucosyltransferase (MGS) induces fatty acid remodeling in Escherichia coli membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1862-70. [PMID: 24726609 DOI: 10.1016/j.bbamem.2014.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/27/2014] [Accepted: 04/02/2014] [Indexed: 01/14/2023]
Abstract
The membrane protein monoglucosyldiacylglycerol synthase (MGS) from Acholeplasma laidlawii is responsible for the creation of intracellular membranes when overexpressed in Escherichia coli (E. coli). The present study investigates time dependent changes in composition and properties of E. coli membranes during 22h of MGS induction. The lipid/protein ratio increased by 38% in MGS-expressing cells compared to control cells. Time-dependent screening of lipids during this period indicated differences in fatty acid modeling. (1) Unsaturation levels remained constant for MGS cells (~62%) but significantly decreased in control cells (from 61% to 36%). (2) Cyclopropanated fatty acid content was lower in MGS producing cells while control cells had an increased cyclopropanation activity. Among all lipids, phosphatidylethanolamine (PE) was detected to be the most affected species in terms of cyclopropanation. Higher levels of unsaturation, lowered cyclopropanation levels and decreased transcription of the gene for cyclopropane fatty acid synthase (CFA) all indicate the tendency of the MGS protein to force E. coli membranes to alter its usual fatty acid composition.
Collapse
Affiliation(s)
- Candan Ariöz
- The Arrhenius Laboratories for Natural Sciences, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden.
| | - Hansjörg Götzke
- The Arrhenius Laboratories for Natural Sciences, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ljubica Lindholm
- The Arrhenius Laboratories for Natural Sciences, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Jonny Eriksson
- BMC, Department of Chemistry, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Katarina Edwards
- BMC, Department of Chemistry, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Daniel O Daley
- The Arrhenius Laboratories for Natural Sciences, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Andreas Barth
- The Arrhenius Laboratories for Natural Sciences, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ake Wieslander
- The Arrhenius Laboratories for Natural Sciences, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden
| |
Collapse
|
13
|
Albesa-Jové D, Giganti D, Jackson M, Alzari PM, Guerin ME. Structure-function relationships of membrane-associated GT-B glycosyltransferases. Glycobiology 2013; 24:108-24. [PMID: 24253765 DOI: 10.1093/glycob/cwt101] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Membrane-associated GT-B glycosyltransferases (GTs) comprise a large family of enzymes that catalyze the transfer of a sugar moiety from nucleotide-sugar donors to a wide range of membrane-associated acceptor substrates, mostly in the form of lipids and proteins. As a consequence, they generate a significant and diverse amount of glycoconjugates in biological membranes, which are particularly important in cell-cell, cell-matrix and host-pathogen recognition events. Membrane-associated GT-B enzymes display two "Rossmann-fold" domains separated by a deep cleft that includes the catalytic center. They associate permanently or temporarily to the phospholipid bilayer by a combination of hydrophobic and electrostatic interactions. They have the remarkable property to access both hydrophobic and hydrophilic substrates that reside within chemically distinct environments catalyzing their enzymatic transformations in an efficient manner. Here, we discuss the considerable progress that has been made in recent years in understanding the molecular mechanism that governs substrate and membrane recognition, and the impact of the conformational transitions undergone by these GTs during the catalytic cycle.
Collapse
Affiliation(s)
- David Albesa-Jové
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
| | | | | | | | | |
Collapse
|