101
|
Aktas M, Narberhaus F. Unconventional membrane lipid biosynthesis inXanthomonas campestris. Environ Microbiol 2015; 17:3116-24. [DOI: 10.1111/1462-2920.12956] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 06/03/2015] [Accepted: 06/14/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Meriyem Aktas
- Microbial Biology; Ruhr University Bochum; Universitätsstrasse 150, NDEF 06/783 Bochum D-44780 Germany
| | - Franz Narberhaus
- Microbial Biology; Ruhr University Bochum; Universitätsstrasse 150, NDEF 06/783 Bochum D-44780 Germany
| |
Collapse
|
102
|
Kondakova T, D'Heygère F, Feuilloley MJ, Orange N, Heipieper HJ, Duclairoir Poc C. Glycerophospholipid synthesis and functions in Pseudomonas. Chem Phys Lipids 2015; 190:27-42. [PMID: 26148574 DOI: 10.1016/j.chemphyslip.2015.06.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 06/29/2015] [Accepted: 06/30/2015] [Indexed: 11/25/2022]
Abstract
The genus Pseudomonas is one of the most heterogeneous groups of eubacteria, presents in all major natural environments and in wide range of associations with plants and animals. The wide distribution of these bacteria is due to the use of specific mechanisms to adapt to environmental modifications. Generally, bacterial adaptation is only considered under the aspect of genes and protein expression, but lipids also play a pivotal role in bacterial functioning and homeostasis. This review resumes the mechanisms and regulations of pseudomonal glycerophospholipid synthesis, and the roles of glycerophospholipids in bacterial metabolism and homeostasis. Recently discovered specific pathways of P. aeruginosa lipid synthesis indicate the lineage dependent mechanisms of fatty acids homeostasis. Pseudomonas glycerophospholipids ensure structure functions and play important roles in bacterial adaptation to environmental modifications. The lipidome of Pseudomonas contains a typical eukaryotic glycerophospholipid--phosphatidylcholine -, which is involved in bacteria-host interactions. The ability of Pseudomonas to exploit eukaryotic lipids shows specific and original strategies developed by these microorganisms to succeed in their infectious process. All compiled data provide the demonstration of the importance of studying the Pseudomonas lipidome to inhibit the infectious potential of these highly versatile germs.
Collapse
Affiliation(s)
- Tatiana Kondakova
- Normandie University of Rouen, Laboratory of Microbiology Signals and Microenvironment (LMSM), EA 4312, 55 rue St. Germain, 27000 Evreux, France
| | - François D'Heygère
- Centre de Biophysique Moléculaire, CNRS, UPR4301, rue Charles Sadron, 45071 Orléans, France
| | - Marc J Feuilloley
- Normandie University of Rouen, Laboratory of Microbiology Signals and Microenvironment (LMSM), EA 4312, 55 rue St. Germain, 27000 Evreux, France
| | - Nicole Orange
- Normandie University of Rouen, Laboratory of Microbiology Signals and Microenvironment (LMSM), EA 4312, 55 rue St. Germain, 27000 Evreux, France
| | - Hermann J Heipieper
- Department of Environmental Biotechnology, UFZ Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Cécile Duclairoir Poc
- Normandie University of Rouen, Laboratory of Microbiology Signals and Microenvironment (LMSM), EA 4312, 55 rue St. Germain, 27000 Evreux, France.
| |
Collapse
|
103
|
Rice AJ, Alvarez FJD, Davidson AL, Pinkett HW. Effects of lipid environment on the conformational changes of an ABC importer. Channels (Austin) 2015; 8:327-33. [PMID: 24852576 PMCID: PMC4203734 DOI: 10.4161/chan.29294] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In order to shuttle substrates across the lipid bilayer, membrane proteins undergo a series of conformation changes that are influenced by protein structure, ligands, and the lipid environment. To test the effect of lipid on conformation change of the ABC transporter MolBC, EPR studies were conducted in lipids and detergents of variable composition. In both a detergent and lipid environment, MolBC underwent the same general conformation changes as detected by site-directed EPR spectroscopy. However, differences in activity and the details of the EPR analysis indicate conformational rigidity that is dependent on the lipid environment. From these observations, we conclude that native-like lipid mixtures provide the transporter with greater activity and conformational flexibility as well as technical advantages such as reconstitution efficiency and protein stability.
Collapse
|
104
|
Conserved SMP domains of the ERMES complex bind phospholipids and mediate tether assembly. Proc Natl Acad Sci U S A 2015; 112:E3179-88. [PMID: 26056272 DOI: 10.1073/pnas.1422363112] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Membrane contact sites (MCS) between organelles are proposed as nexuses for the exchange of lipids, small molecules, and other signals crucial to cellular function and homeostasis. Various protein complexes, such as the endoplasmic reticulum-mitochondrial encounter structure (ERMES), function as dynamic molecular tethers between organelles. Here, we report the reconstitution and characterization of subcomplexes formed by the cytoplasm-exposed synaptotagmin-like mitochondrial lipid-binding protein (SMP) domains present in three of the five ERMES subunits--the soluble protein Mdm12, the endoplasmic reticulum (ER)-resident membrane protein Mmm1, and the mitochondrial membrane protein Mdm34. SMP domains are conserved lipid-binding domains found exclusively in proteins at MCS. We show that the SMP domains of Mdm12 and Mmm1 associate into a tight heterotetramer with equimolecular stoichiometry. Our 17-Å-resolution EM structure of the complex reveals an elongated crescent-shaped particle in which two Mdm12 subunits occupy symmetric but distal positions at the opposite ends of a central ER-anchored Mmm1 homodimer. Rigid body fitting of homology models of these SMP domains in the density maps reveals a distinctive extended tubular structure likely traversed by a hydrophobic tunnel. Furthermore, these two SMP domains bind phospholipids and display a strong preference for phosphatidylcholines, a class of phospholipids whose exchange between the ER and mitochondria is essential. Last, we show that the three SMP-containing ERMES subunits form a ternary complex in which Mdm12 bridges Mmm1 to Mdm34. Our findings highlight roles for SMP domains in ERMES assembly and phospholipid binding and suggest a structure-based mechanism for the facilitated transport of phospholipids between organelles.
Collapse
|
105
|
Chang FY, Ternei MA, Calle PY, Brady SF. Targeted metagenomics: finding rare tryptophan dimer natural products in the environment. J Am Chem Soc 2015; 137:6044-52. [PMID: 25872030 PMCID: PMC4839266 DOI: 10.1021/jacs.5b01968] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Natural product discovery from environmental genomes (metagenomics) has largely been limited to the screening of existing environmental DNA (eDNA) libraries. Here, we have coupled a chemical-biogeographic survey of chromopyrrolic acid synthase (CPAS) gene diversity with targeted eDNA library production to more efficiently access rare tryptophan dimer (TD) biosynthetic gene clusters. A combination of traditional and synthetic biology-based heterologous expression efforts using eDNA-derived gene clusters led to the production of hydroxysporine (1) and reductasporine (2), two bioactive TDs. As suggested by our phylogenetic analysis of CPAS genes, identified in our survey of crude eDNA extracts, reductasporine (2) contains an unprecedented TD core structure: a pyrrolinium indolocarbazole core that is likely key to its unusual bioactivity profile. This work demonstrates the potential for the discovery of structurally rare and biologically interesting natural products using targeted metagenomics, where environmental samples are prescreened to identify the most phylogenetically unique gene sequences and molecules associated with these genes are accessed through targeted metagenomic library construction and heterologous expression.
Collapse
Affiliation(s)
- Fang-Yuan Chang
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065
| | - Melinda A. Ternei
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065
| | - Paula Y. Calle
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065
| | - Sean F. Brady
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065
| |
Collapse
|
106
|
Escobedo-Hinojosa WI, Vences-Guzmán MÁ, Schubotz F, Sandoval-Calderón M, Summons RE, López-Lara IM, Geiger O, Sohlenkamp C. OlsG (Sinac_1600) Is an Ornithine Lipid N-Methyltransferase from the Planctomycete Singulisphaera acidiphila. J Biol Chem 2015; 290:15102-11. [PMID: 25925947 DOI: 10.1074/jbc.m115.639575] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Indexed: 11/06/2022] Open
Abstract
Ornithine lipids (OLs) are phosphorus-free membrane lipids widespread in bacteria but absent from archaea and eukaryotes. In addition to the unmodified OLs, a variety of OL derivatives hydroxylated in different structural positions has been reported. Recently, methylated derivatives of OLs were described in several planctomycetes isolated from a peat bog in Northern Russia, although the gene/enzyme responsible for the N-methylation of OL remained obscure. Here we identify and characterize the OL N-methyltransferase OlsG (Sinac_1600) from the planctomycete Singulisphaera acidiphila. When OlsG is co-expressed with the OL synthase OlsF in Escherichia coli, methylated OL derivatives are formed. An in vitro characterization shows that OlsG is responsible for the 3-fold methylation of the terminal δ-nitrogen of OL. Methylation is dependent on the presence of the detergent Triton X-100 and the methyldonor S-adenosylmethionine.
Collapse
Affiliation(s)
- Wendy Itzel Escobedo-Hinojosa
- From the Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos CP62210, Mexico and
| | - Miguel Ángel Vences-Guzmán
- From the Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos CP62210, Mexico and
| | - Florence Schubotz
- the Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02144
| | - Mario Sandoval-Calderón
- From the Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos CP62210, Mexico and
| | - Roger E Summons
- the Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02144
| | - Isabel María López-Lara
- From the Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos CP62210, Mexico and
| | - Otto Geiger
- From the Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos CP62210, Mexico and
| | - Christian Sohlenkamp
- From the Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos CP62210, Mexico and
| |
Collapse
|
107
|
Sohlenkamp C, Geiger O. Bacterial membrane lipids: diversity in structures and pathways. FEMS Microbiol Rev 2015; 40:133-59. [DOI: 10.1093/femsre/fuv008] [Citation(s) in RCA: 571] [Impact Index Per Article: 63.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2015] [Indexed: 12/22/2022] Open
|
108
|
Sun J, Zhou J, Wang Z, He W, Zhang D, Tong Q, Su X. Multi-omics based changes in response to cadmium toxicity in Bacillus licheniformis A. RSC Adv 2015. [DOI: 10.1039/c4ra15280h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cadmium (Cd), a widespread substance with high toxicity and persistence, is known to cause a broad range of adverse effects in all living organisms.
Collapse
Affiliation(s)
- Jing Sun
- School of Marine Sciences
- Ningbo University
- Ningbo 315211
- China
- College of Food Science and Technology
| | - Jun Zhou
- School of Marine Sciences
- Ningbo University
- Ningbo 315211
- China
| | - Zhonghua Wang
- School of Marine Sciences
- Ningbo University
- Ningbo 315211
- China
| | - Weina He
- School of Marine Sciences
- Ningbo University
- Ningbo 315211
- China
| | - Dijun Zhang
- School of Marine Sciences
- Ningbo University
- Ningbo 315211
- China
| | - Qianqian Tong
- School of Marine Sciences
- Ningbo University
- Ningbo 315211
- China
| | - Xiurong Su
- School of Marine Sciences
- Ningbo University
- Ningbo 315211
- China
| |
Collapse
|
109
|
Zhang D, Gao G, Guy L, Robert V, Dutasta JP, Martinez A. A fluorescent heteroditopic hemicryptophane cage for the selective recognition of choline phosphate. Chem Commun (Camb) 2015; 51:2679-82. [DOI: 10.1039/c4cc09428j] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first fluorescent hemicryptophane cage was synthesized and developed as an efficient and selective sensor for choline phosphate.
Collapse
Affiliation(s)
- Dawei Zhang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes
- Department of Chemistry
- East China Normal University
- Shanghai
- P. R. China
| | - Guohua Gao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes
- Department of Chemistry
- East China Normal University
- Shanghai
- P. R. China
| | - Laure Guy
- Laboratoire de Chimie
- CNRS
- École Normale Supérieure de Lyon
- F-69364 Lyon
- France
| | - Vincent Robert
- Laboratoire de Chimie Quantique Institut de Chimie
- UMR CNRS 7177
- Université de Strasbourg
- F-67070 Strasbourg
- France
| | | | - Alexandre Martinez
- Laboratoire de Chimie
- CNRS
- École Normale Supérieure de Lyon
- F-69364 Lyon
- France
| |
Collapse
|
110
|
Yang X, Shang H, Ding C, Li J. Recent developments and applications of bioinspired dendritic polymers. Polym Chem 2015. [DOI: 10.1039/c4py01537a] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review highlights the bioinspired applications of dendritic polymers, focusing on their structure–function relationship to natural biomolecules such as proteins.
Collapse
Affiliation(s)
- Xiao Yang
- College of Polymer Science and Engineering
- Sichuan University
- Chengdu 610065
- China
| | - Hui Shang
- College of Polymer Science and Engineering
- Sichuan University
- Chengdu 610065
- China
| | - Chunmei Ding
- College of Polymer Science and Engineering
- Sichuan University
- Chengdu 610065
- China
| | - Jianshu Li
- College of Polymer Science and Engineering
- Sichuan University
- Chengdu 610065
- China
- State Key Laboratory of Polymer Materials Engineering
| |
Collapse
|
111
|
Liu L, Park SJ, Park JH, Lee ME. Facile syntheses of alkoxysilanated phosphorylcholines as surface modifiers: CuAAC and thiol-ene “click” reactions. RSC Adv 2015. [DOI: 10.1039/c4ra15716h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Alkoxysilanated PCs were synthesizedviaCuAAC and thiol-ene “click” reactions and used as surface modifiers on silica beads.
Collapse
Affiliation(s)
- Lei Liu
- Department of Chemistry & Medical Chemistry
- College of Science and Technology
- Research & Education Center for Advanced Silicon Materials
- Yonsei University
- Wonju
| | - Sung Jin Park
- Department of Chemistry & Medical Chemistry
- College of Science and Technology
- Research & Education Center for Advanced Silicon Materials
- Yonsei University
- Wonju
| | - Ji-hyun Park
- Department of Chemistry & Medical Chemistry
- College of Science and Technology
- Research & Education Center for Advanced Silicon Materials
- Yonsei University
- Wonju
| | - Myong Euy Lee
- Department of Chemistry & Medical Chemistry
- College of Science and Technology
- Research & Education Center for Advanced Silicon Materials
- Yonsei University
- Wonju
| |
Collapse
|
112
|
Danne L, Aktas M, Gleichenhagen J, Grund N, Wagner D, Schwalbe H, Hoffknecht B, Metzler-Nolte N, Narberhaus F. Membrane-binding mechanism of a bacterial phospholipid N-methyltransferase. Mol Microbiol 2014; 95:313-31. [DOI: 10.1111/mmi.12870] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2014] [Indexed: 12/20/2022]
Affiliation(s)
- Linna Danne
- Microbial Biology; Ruhr University Bochum; Bochum Germany
| | - Meriyem Aktas
- Microbial Biology; Ruhr University Bochum; Bochum Germany
| | | | - Nadine Grund
- Microbial Biology; Ruhr University Bochum; Bochum Germany
| | - Dominic Wagner
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ); University of Frankfurt; Frankfurt Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ); University of Frankfurt; Frankfurt Germany
| | | | | | | |
Collapse
|
113
|
Davies JM, Hua HU, Dheer R, Martinez M, Bhattacharya SK, Abreu MT. Stool phospholipid signature is altered by diet and tumors. PLoS One 2014; 9:e114352. [PMID: 25469718 PMCID: PMC4254978 DOI: 10.1371/journal.pone.0114352] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Accepted: 11/09/2014] [Indexed: 12/13/2022] Open
Abstract
Intake of saturated fat is a risk factor for ulcerative colitis (UC) and colon cancer. Changes in the microbiota have been implicated in the development of UC and colon cancer. The host and the microbiota generate metabolites that may contribute to or reflect disease pathogenesis. We used lipid class specific quantitative mass spectrometry to assess the phospholipid (PL) profile (phosphatidylcholine [PC], phosphatidylethanolamine [PE], phosphatidylinositol [PI], phosphatidylserine [PS]) of stool from mice fed a high fat (HFD) or control diet with or without induction of colitis-associated tumors using azoxymethane and dextran sodium sulfate. The microbiota was assessed using qPCR for several bacterial groups. Colitis-associated tumors were associated with reduced bulk PI and PE levels in control diet fed mice compared to untreated mice. Significant decreases in the relative quantities of several PC species were found in colitis-associated tumor bearing mice fed either diet. Statistical analysis of the PL profile revealed distinct clustering by treatment group. Partial least squares regression analysis found that the relative quantities of the PS class profile best predicted bacterial abundance of Clostridium leptum and Prevotella groups. Abundance of selected PL species correlated with bacterial group quantities. Thus, we have described that a HFD and colitis-associated tumors are associated with changes in phospholipids and may reflect host-microbial interactions and disease states.
Collapse
Affiliation(s)
- Julie M. Davies
- Division of Gastroenterology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Hong-Uyen Hua
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States of America
| | - Rishu Dheer
- Division of Gastroenterology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
| | - Mitchell Martinez
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States of America
| | - Sanjoy K. Bhattacharya
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States of America
| | - Maria T. Abreu
- Division of Gastroenterology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida, United States of America
- * E-mail:
| |
Collapse
|
114
|
Impact of the glpQ2 gene on virulence in a Streptococcus pneumoniae serotype 19A sequence type 320 strain. Infect Immun 2014; 83:682-92. [PMID: 25422269 DOI: 10.1128/iai.02357-14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Glycerophosphodiester phosphodiesterase (GlpQ) metabolizes glycerophosphorylcholine from the lung epithelium to produce free choline, which is transformed into phosphorylcholine and presented on the surfaces of many respiratory pathogens. Two orthologs of glpQ genes are found in Streptococcus pneumoniae: glpQ, with a membrane motif, is widespread in pneumococci, whereas glpQ2, which shares high similarity with glpQ in Haemophilus influenzae and Mycoplasma pneumoniae, is present only in S. pneumoniae serotype 3, 6B, 19A, and 19F strains. Recently, serotype 19A has emerged as an epidemiological etiology associated with invasive pneumococcal diseases. Thus, we investigated the pathophysiological role of glpQ2 in a serotype 19A sequence type 320 (19AST320) strain, which was the prevalent sequence type in 19A associated with severe pneumonia and invasive pneumococcal disease in pediatric patients. Mutations in glpQ2 reduced phosphorylcholine expression and the anchorage of choline-binding proteins to the pneumococcal surface during the exponential phase, where the mutants exhibited reduced autolysis and lower natural transformation abilities than the parent strain. The deletion of glpQ2 also decreased the adherence and cytotoxicity to human lung epithelial cell lines, whereas these functions were indistinguishable from those of the wild type in complementation strains. In a murine respiratory tract infection model, glpQ2 was important for nasopharynx and lung colonization. Furthermore, infection with a glpQ2 mutant decreased the severity of pneumonia compared with the parent strain, and glpQ2 gene complementation restored the inflammation level. Therefore, glpQ2 enhances surface phosphorylcholine expression in S. pneumoniae 19AST320 during the exponential phase, which contributes to the severity of pneumonia by promoting adherence and host cell cytotoxicity.
Collapse
|
115
|
Synthesis and application of moisture-stable methallylsilanated phosphorylcholine as a surface modifier. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.09.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
116
|
Zeng XF, Ma Y, Yang L, Zhou L, Xin Y, Chang L, Zhang JR, Hao X. A C-terminal truncated mutation of licC attenuates the virulence of Streptococcus pneumoniae. Res Microbiol 2014; 165:630-8. [PMID: 25283725 DOI: 10.1016/j.resmic.2014.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 08/21/2014] [Accepted: 09/11/2014] [Indexed: 10/24/2022]
Abstract
LicC has been identified as a virulence factor of Streptococcus pneumoniae. However, its role in virulence is still not fully understood because deletion of licC is lethal for the bacterium. In this study, a mutant with 78-bp truncation at the C-terminus of licC was obtained from a signature-tagged mutagenesis (STM) library. The mutant was viable with a large reduction in enzymatic activity as CTP:phosphocholine cytidylyltransferase detected in vitro using a firefly luciferase assay. The mutation attenuated the adhesion and invasion of S. pneumoniae ST556 (serotype 19F) to epithelial cells by 72% and 80%, respectively, and increased the phagocytosis by macrophages for 16.5%, compared to the parental strain. When the mutation was introduced into the encapsulated D39 strain (serotype 2), it led to attenuated virulence in mouse models either by intranasal colonization or by intraperitoneal infection. In addition, the phosphocholine (PCho) on cell surface was decreased, and the choline binding proteins (CBPs) were impaired, which may explain the attenuated virulence of the mutant. These observations indicate that C-terminus of licC is accounted for the main activity of LicC in PCho metabolism and is essential for the virulence of S. pneumoniae, which provides a novel target for drug design against pneumococcal infection.
Collapse
Affiliation(s)
- Xian-Fei Zeng
- Department of Clinical Laboratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Yueyun Ma
- Department of Clinical Laboratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Liu Yang
- Department of Clinical Laboratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Lei Zhou
- Department of Clinical Laboratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Yijuan Xin
- Department of Clinical Laboratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Liang Chang
- Department of Clinical Laboratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Jing-Ren Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100017, China.
| | - Xiaoke Hao
- Department of Clinical Laboratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| |
Collapse
|
117
|
Enzymatic properties and substrate specificity of a bacterial phosphatidylcholine synthase. FEBS J 2014; 281:3523-41. [DOI: 10.1111/febs.12877] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 06/11/2014] [Accepted: 06/11/2014] [Indexed: 11/26/2022]
|
118
|
Reeves EP, Yoshinaga MY, Pjevac P, Goldenstein NI, Peplies J, Meyerdierks A, Amann R, Bach W, Hinrichs KU. Microbial lipids reveal carbon assimilation patterns on hydrothermal sulfide chimneys. Environ Microbiol 2014; 16:3515-32. [DOI: 10.1111/1462-2920.12525] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/25/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Eoghan P. Reeves
- MARUM Center for Marine Environmental Sciences & Department of Geosciences; University of Bremen; Bremen D-28359 Germany
| | - Marcos Y. Yoshinaga
- MARUM Center for Marine Environmental Sciences & Department of Geosciences; University of Bremen; Bremen D-28359 Germany
| | - Petra Pjevac
- Department of Molecular Ecology; Max Planck Institute for Marine Microbiology; Bremen D-28359 Germany
| | - Nadine I. Goldenstein
- MARUM Center for Marine Environmental Sciences & Department of Geosciences; University of Bremen; Bremen D-28359 Germany
| | - Jörg Peplies
- Department of Molecular Ecology; Max Planck Institute for Marine Microbiology; Bremen D-28359 Germany
- Ribocon GmbH; Fahrenheitstrasse 1 Bremen D-28359 Germany
| | - Anke Meyerdierks
- Department of Molecular Ecology; Max Planck Institute for Marine Microbiology; Bremen D-28359 Germany
| | - Rudolf Amann
- Department of Molecular Ecology; Max Planck Institute for Marine Microbiology; Bremen D-28359 Germany
| | - Wolfgang Bach
- MARUM Center for Marine Environmental Sciences & Department of Geosciences; University of Bremen; Bremen D-28359 Germany
| | - Kai-Uwe Hinrichs
- MARUM Center for Marine Environmental Sciences & Department of Geosciences; University of Bremen; Bremen D-28359 Germany
| |
Collapse
|
119
|
Quantifying absolute protein synthesis rates reveals principles underlying allocation of cellular resources. Cell 2014; 157:624-35. [PMID: 24766808 DOI: 10.1016/j.cell.2014.02.033] [Citation(s) in RCA: 894] [Impact Index Per Article: 89.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 12/31/2013] [Accepted: 02/11/2014] [Indexed: 11/23/2022]
Abstract
Quantitative views of cellular functions require precise measures of rates of biomolecule production, especially proteins-the direct effectors of biological processes. Here, we present a genome-wide approach, based on ribosome profiling, for measuring absolute protein synthesis rates. The resultant E. coli data set transforms our understanding of the extent to which protein synthesis is precisely controlled to optimize function and efficiency. Members of multiprotein complexes are made in precise proportion to their stoichiometry, whereas components of functional modules are produced differentially according to their hierarchical role. Estimates of absolute protein abundance also reveal principles for optimizing design. These include how the level of different types of transcription factors is optimized for rapid response and how a metabolic pathway (methionine biosynthesis) balances production cost with activity requirements. Our studies reveal how general principles, important both for understanding natural systems and for synthesizing new ones, emerge from quantitative analyses of protein synthesis.
Collapse
|
120
|
Legionella dumoffii utilizes exogenous choline for phosphatidylcholine synthesis. Int J Mol Sci 2014; 15:8256-79. [PMID: 24821544 PMCID: PMC4057730 DOI: 10.3390/ijms15058256] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 04/20/2014] [Accepted: 04/23/2014] [Indexed: 12/05/2022] Open
Abstract
Phosphatidycholine (PC) is the major membrane-forming phospholipid in eukaryotes but it has been found in only a limited number of prokaryotes. Bacteria synthesize PC via the phospholipid N-methylation pathway (Pmt) or via the phosphatidylcholine synthase pathway (Pcs) or both. Here, we demonstrated that Legionella dumoffii has the ability to utilize exogenous choline for phosphatidylcholine (PC) synthesis when bacteria grow in the presence of choline. The Pcs seems to be a primary pathway for synthesis of this phospholipid in L. dumoffii. Structurally different PC species were distributed in the outer and inner membranes. As shown by the LC/ESI-MS analyses, PC15:0/15:0, PC16:0/15:0, and PC17:0/17:1 were identified in the outer membrane and PC14:0/16:0, PC16:0/17:1, and PC20:0/15:0 in the inner membrane. L. dumoffii pcsA gene encoding phosphatidylcholine synthase revealed the highest sequence identity to pcsA of L. bozemanae (82%) and L. longbeachae (81%) and lower identity to pcsA of L. drancourtii (78%) and L. pneumophila (71%). The level of TNF-α in THP1-differentiated cells induced by live and temperature-killed L. dumoffii cultured on a medium supplemented with choline was assessed. Live L. dumoffii bacteria cultured on the choline-supplemented medium induced TNF-α three-fold less efficiently than cells grown on the non-supplemented medium. There is an evident effect of PC modification, which impairs the macrophage inflammatory response.
Collapse
|
121
|
Moser R, Aktas M, Fritz C, Narberhaus F. Discovery of a bifunctional cardiolipin/phosphatidylethanolamine synthase in bacteria. Mol Microbiol 2014; 92:959-72. [DOI: 10.1111/mmi.12603] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2014] [Indexed: 01/22/2023]
Affiliation(s)
- Roman Moser
- Microbial Biology; Ruhr University Bochum; Bochum Germany
| | - Meriyem Aktas
- Microbial Biology; Ruhr University Bochum; Bochum Germany
| | | | | |
Collapse
|
122
|
Aktas M, Danne L, Möller P, Narberhaus F. Membrane lipids in Agrobacterium tumefaciens: biosynthetic pathways and importance for pathogenesis. FRONTIERS IN PLANT SCIENCE 2014; 5:109. [PMID: 24723930 PMCID: PMC3972451 DOI: 10.3389/fpls.2014.00109] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/07/2014] [Indexed: 05/25/2023]
Abstract
Many cellular processes critically depend on the membrane composition. In this review, we focus on the biosynthesis and physiological roles of membrane lipids in the plant pathogen Agrobacterium tumefaciens. The major components of A. tumefaciens membranes are the phospholipids (PLs), phosphatidylethanolamine (PE), phosphatidylglycerol, phosphatidylcholine (PC) and cardiolipin, and ornithine lipids (OLs). Under phosphate-limited conditions, the membrane composition shifts to phosphate-free lipids like glycolipids, OLs and a betaine lipid. Remarkably, PC and OLs have opposing effects on virulence of A. tumefaciens. OL-lacking A. tumefaciens mutants form tumors on the host plant earlier than the wild type suggesting a reduced host defense response in the absence of OLs. In contrast, A. tumefaciens is compromised in tumor formation in the absence of PC. In general, PC is a rare component of bacterial membranes but amount to ~22% of all PLs in A. tumefaciens. PC biosynthesis occurs via two pathways. The phospholipid N-methyltransferase PmtA methylates PE via the intermediates monomethyl-PE and dimethyl-PE to PC. In the second pathway, the membrane-integral enzyme PC synthase (Pcs) condenses choline with CDP-diacylglycerol to PC. Apart from the virulence defect, PC-deficient A. tumefaciens pmtA and pcs double mutants show reduced motility, enhanced biofilm formation and increased sensitivity towards detergent and thermal stress. In summary, there is cumulative evidence that the membrane lipid composition of A. tumefaciens is critical for agrobacterial physiology and tumor formation.
Collapse
Affiliation(s)
| | | | | | - Franz Narberhaus
- *Correspondence: Franz Narberhaus, Microbial Biology, Department for Biology and Biotechnology, Ruhr University Bochum, Universitätsstrasse 150, NDEF 06/783, 44780 Bochum, Germany e-mail:
| |
Collapse
|
123
|
Xiong M, Long D, He H, Li Y, Li Y, Wang X. Phosphatidylcholine synthesis is essential for HrpZ harpin secretion in plant pathogenic Pseudomonas syringae and non-pathogenic Pseudomonas sp. 593. Microbiol Res 2014; 169:196-204. [PMID: 23886927 DOI: 10.1016/j.micres.2013.06.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 06/21/2013] [Accepted: 06/22/2013] [Indexed: 10/26/2022]
Abstract
Pseudomonas syringae pv. syringae van Hall is important phytopathogenic bacterium of stone fruit trees, and able to elicit hypersensitive response (HR) in nonhost plants. The HrpZ, secreted via type III secretion system (T3SS) to the extracellular space of the plant, is a T3SS-dependent protein and a sole T3SS effector able to induce the host defense response outside host cells. We deleted the phosphatidylcholine synthase gene (pcs) of P. syringae pv. syringae van Hall CFCC 1336, and found that the 1336 pcs(-) mutant was unable to synthesize phosphatidylcholine and elicit a typical HR in soybean. Further studies showed that the 1336 pcs(-) mutant was unable to secrete HrpZ harpin but could express HrpZ protein in cytoplasm as effectively as the wild type. To confirm if phosphatidylcholine affects HrpZ harpin secretion, we introduced the hrpZ gene into the soil-dwelling bacterium Pseudomonas sp. 593 and the 593 pcs(-) mutant, which were unable to express HrpZ harpin and elicit HR in tobacco or soybean. Western blotting and HR assay showed that the 593H not only secreted HrpZ harpin but also caused a strong HR in tobacco and soybean. In contrast, the 593 pcs(-)H only expressed HrpZ protein in its cytoplasm at the wild type level, but did not secrete HrpZ harpin or elicit HR reaction. Our results demonstrate that phosphatidylcholine is essential for the secretion of HrpZ harpin in P. syringae pv. syringae van Hall and other Pseudomonas strains.
Collapse
Affiliation(s)
- Min Xiong
- The Faculty of Life Science, Hubei University, China
| | - Deliang Long
- The Faculty of Life Science, Hubei University, China
| | - Huoguang He
- The Faculty of Life Science, Hubei University, China
| | - Yang Li
- The Faculty of Life Science, Hubei University, China
| | - Yadong Li
- The Faculty of Life Science, Hubei University, China
| | - Xingguo Wang
- The Faculty of Life Science, Hubei University, China.
| |
Collapse
|
124
|
Cregut M, Durand MJ, Thouand G. The diversity and functions of choline sulphatases in microorganisms. MICROBIAL ECOLOGY 2014; 67:350-357. [PMID: 24281732 DOI: 10.1007/s00248-013-0328-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 11/11/2013] [Indexed: 06/02/2023]
Abstract
Choline sulphates have two putative roles in microorganisms: as a reservoir of C, N and S and as osmoprotectants. Although there is no established connection to date regarding the relative distribution of these two functions in microbial communities, this information is crucial in determining the role of choline sulphate in soils, particularly in cultivated soils where S is limiting. Therefore, in order to establish such a connection, the diversity of choline sulphatase (betC) genes was investigated in this study using numerous fully sequenced microbes available in GenBank. Our genomic analyses revealed unequivocally that the betICBA operon is restricted to Rhizobiaceae family members, which live under symbiotic conditions that prevent elemental depletion. Together with the uniform genetic organisation of the betICBA operon in Rhizobiaceae, BetC appears to be both utilised for osmoprotection or S replenishment. In contrast, betC in a wide variety of free-living microbes (including fungi, archaea and bacteria) was found in a cassette encoding only BetC and a choline sulphate transporter, a configuration that appears to be responsible for fulfilling elemental S requirements. Lastly, the relatively high number of BetC sequences available allowed the identification of a specific signature sequence that discriminates between these two functions and also globally defines some conserved motifs in microbial choline sulphatases. Due to the widespread presence of BetC in microbes and the wide repartition of the betC cassette system, the potential importance of choline sulphatase in global S recycling requires further clarification.
Collapse
Affiliation(s)
- Mickael Cregut
- UMR 6144 GEPEA CNRS, CBAC, University of Nantes, 18 Bvd Gaston Defferre, La Roche-sur-Yon, France,
| | | | | |
Collapse
|
125
|
Biller SJ, Schubotz F, Roggensack SE, Thompson AW, Summons RE, Chisholm SW. Bacterial vesicles in marine ecosystems. Science 2014; 343:183-6. [PMID: 24408433 DOI: 10.1126/science.1243457] [Citation(s) in RCA: 313] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Many heterotrophic bacteria are known to release extracellular vesicles, facilitating interactions between cells and their environment from a distance. Vesicle production has not been described in photoautotrophs, however, and the prevalence and characteristics of vesicles in natural ecosystems is unknown. Here, we report that cultures of Prochlorococcus, a numerically dominant marine cyanobacterium, continuously release lipid vesicles containing proteins, DNA, and RNA. We also show that vesicles carrying DNA from diverse bacteria are abundant in coastal and open-ocean seawater samples. Prochlorococcus vesicles can support the growth of heterotrophic bacterial cultures, which implicates these structures in marine carbon flux. The ability of vesicles to deliver diverse compounds in discrete packages adds another layer of complexity to the flow of information, energy, and biomolecules in marine microbial communities.
Collapse
Affiliation(s)
- Steven J Biller
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | | | | | | | |
Collapse
|
126
|
Fürst O, Mondou B, D'Avanzo N. Phosphoinositide regulation of inward rectifier potassium (Kir) channels. Front Physiol 2014; 4:404. [PMID: 24409153 PMCID: PMC3884141 DOI: 10.3389/fphys.2013.00404] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 12/23/2013] [Indexed: 12/12/2022] Open
Abstract
Inward rectifier potassium (Kir) channels are integral membrane proteins charged with a key role in establishing the resting membrane potential of excitable cells through selective control of the permeation of K+ ions across cell membranes. In conjunction with secondary anionic phospholipids, members of this family are directly regulated by phosphoinositides (PIPs) in the absence of other proteins or downstream signaling pathways. Different Kir isoforms display distinct specificities for the activating PIPs but all eukaryotic Kir channels are activated by PI(4,5)P2. On the other hand, the bacterial KirBac1.1 channel is inhibited by PIPs. Recent crystal structures of eukaryotic Kir channels in apo and lipid bound forms reveal one specific binding site per subunit, formed at the interface of N- and C-terminal domains, just beyond the transmembrane segments and clearly involving some of the key residues previously identified as controlling PI(4,5)P2 sensitivity. Computational, biochemical, and biophysical approaches have attempted to address the energetic determinants of PIP binding and selectivity among Kir channel isoforms, as well as the conformational changes that trigger channel gating. Here we review our current understanding of the molecular determinants of PIP regulation of Kir channel activity, including in context with other lipid modulators, and provide further discussion on the key questions that remain to be answered.
Collapse
Affiliation(s)
- Oliver Fürst
- Groupe d'étude des Protéines Membranaires (GÉPROM), Physiologie, Université de Montréal Montréal, QC, Canada
| | - Benoit Mondou
- Groupe d'étude des Protéines Membranaires (GÉPROM), Physiologie, Université de Montréal Montréal, QC, Canada
| | - Nazzareno D'Avanzo
- Groupe d'étude des Protéines Membranaires (GÉPROM), Physiologie, Université de Montréal Montréal, QC, Canada
| |
Collapse
|
127
|
Moser R, Aktas M, Narberhaus F. Phosphatidylcholine biosynthesis inXanthomonas campestrisvia a yeast-like acylation pathway. Mol Microbiol 2014; 91:736-50. [DOI: 10.1111/mmi.12492] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2013] [Indexed: 12/01/2022]
Affiliation(s)
- Roman Moser
- Microbial Biology; Ruhr University Bochum; Bochum Germany
| | - Meriyem Aktas
- Microbial Biology; Ruhr University Bochum; Bochum Germany
| | | |
Collapse
|
128
|
Schubotz F, Meyer-Dombard DR, Bradley AS, Fredricks HF, Hinrichs KU, Shock EL, Summons RE. Spatial and temporal variability of biomarkers and microbial diversity reveal metabolic and community flexibility in Streamer Biofilm Communities in the Lower Geyser Basin, Yellowstone National Park. GEOBIOLOGY 2013; 11:549-569. [PMID: 23981055 DOI: 10.1111/gbi.12051] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 07/19/2013] [Indexed: 06/02/2023]
Abstract
Detailed analysis of 16S rRNA and intact polar lipids (IPLs) from streamer biofilm communities (SBCs), collected from geochemically similar hot springs in the Lower Geyser Basin, Yellowstone National Park, shows good agreement and affirm that IPLs can be used as reliable markers for the microbial constituents of SBCs. Uncultured Crenarchaea are prominent in SBS, and their IPLs contain both glycosidic and mixed glyco-phospho head groups with tetraether cores, having 0-4 rings. Archaeal IPL contributions increase with increasing temperature and comprise up to one-fourth of the total IPL inventory at >84 °C. At elevated temperatures, bacterial IPLs contain abundant glycosidic glycerol diether lipids. Diether and diacylglycerol (DAG) lipids with aminopentanetetrol and phosphatidylinositol head groups were identified as lipids diagnostic of Aquificales, while DAG glycolipids and glyco-phospholipids containing N-acetylgycosamine as head group were assigned to members of the Thermales. With decreasing temperature and concomitant changes in water chemistry, IPLs typical of phototrophic bacteria, such as mono-, diglycosyl, and sulfoquinovosyl DAG, which are specific for cyanobacteria, increase in abundance, consistent with genomic data from the same samples. Compound-specific stable carbon isotope analysis of IPL breakdown products reveals a large isotopic diversity among SBCs in different hot springs. At two of the hot springs, 'Bison Pool' and Flat Cone, lipids derived from Aquificales are enriched in (13) C relative to biomass and approach values close to dissolved inorganic carbon (DIC) (approximately 0‰), consistent with fractionation during autotrophic carbon fixation via the reversed tricarboxylic acid pathway. At a third site, Octopus Spring, the same Aquificales-diagnostic lipids are 10‰ depleted relative to biomass and resemble stable carbon isotope values of dissolved organic carbon (DOC), indicative of heterotrophy. Other bacterial and archaeal lipids show a similar variance, with values resembling the DIC or DOC pool or a mixture thereof. This variance cannot be explained by hot spring chemistry or temperature alone, but instead, we argue that intermittent input of exogenous organic carbon can result in metabolic shifts of the chemotrophic communities from autotrophy to heterotrophy and vice versa.
Collapse
MESH Headings
- Archaea/classification
- Archaea/genetics
- Bacteria/classification
- Bacteria/genetics
- Biofilms
- Biota
- Cluster Analysis
- DNA, Archaeal/chemistry
- DNA, Archaeal/genetics
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- Genes, rRNA
- Hot Springs/microbiology
- Lipids/analysis
- Molecular Sequence Data
- Phylogeny
- RNA, Archaeal/genetics
- RNA, Bacterial/genetics
- RNA, Ribosomal, 16S/genetics
- Sequence Analysis, DNA
- Sequence Homology, Nucleic Acid
- Temperature
- United States
Collapse
Affiliation(s)
- F Schubotz
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | | | | | | | | | | |
Collapse
|
129
|
Lee SG, Jez JM. Evolution of structure and mechanistic divergence in di-domain methyltransferases from nematode phosphocholine biosynthesis. Structure 2013; 21:1778-87. [PMID: 24012478 PMCID: PMC3797223 DOI: 10.1016/j.str.2013.07.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 07/25/2013] [Accepted: 07/28/2013] [Indexed: 10/26/2022]
Abstract
The phosphobase methylation pathway is the major route for supplying phosphocholine to phospholipid biosynthesis in plants, nematodes, and Plasmodium. In this pathway, phosphoethanolamine N-methyltransferase (PMT) catalyzes the sequential methylation of phosphoethanolamine to phosphocholine. In the PMT, one domain (MT1) catalyzes methylation of phosphoethanolamine to phosphomonomethylethanolamine and a second domain (MT2) completes the synthesis of phosphocholine. The X-ray crystal structures of the di-domain PMT from the parasitic nematode Haemonchus contortus (HcPMT1 and HcPMT2) reveal that the catalytic domains of these proteins are structurally distinct and allow for selective methylation of phosphobase substrates using different active site architectures. These structures also reveal changes leading to loss of function in the vestigial domains of the nematode PMT. Divergence of function in the two nematode PMTs provides two distinct antiparasitic inhibitor targets within the same essential metabolic pathway. The PMTs from nematodes, plants, and Plasmodium also highlight adaptable metabolic modularity in evolutionarily diverse organisms.
Collapse
Affiliation(s)
- Soon Goo Lee
- Department of Biology, Washington University in St. Louis, One Brookings Drive, Campus Box 1137, St. Louis, MO 63130, USA
| | - Joseph M. Jez
- Department of Biology, Washington University in St. Louis, One Brookings Drive, Campus Box 1137, St. Louis, MO 63130, USA
| |
Collapse
|
130
|
Dennison SR, Harris F, Mura M, Morton LHG, Zvelindovsky A, Phoenix DA. A novel form of bacterial resistance to the action of eukaryotic host defense peptides, the use of a lipid receptor. Biochemistry 2013; 52:6021-9. [PMID: 23895279 DOI: 10.1021/bi400719j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Host defense peptides show great potential for development as new antimicrobial agents with novel mechanisms of action. However, a small number of resistance mechanisms to their action are known, and here, we report a novel bacterial resistance mechanism mediated by a lipid receptor. Maximin H5 from Bombina maxima bound anionic and zwitterionic membranes with low affinity (Kd > 225 μM) while showing a strong ability to lyse (>55%) and penetrate (π > 6.0 mN m(-1)) these membranes. However, the peptide bound Escherichia coli and 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) membranes with higher affinity (Kd < 65 μM) and showed a very low ability for bilayer lysis (<8%) and partitioning (π > 1.0 mN m(-1)). Increasing levels of membrane DMPE correlated with enhanced binding by the peptide (R(2) = 0.96) but inversely correlated with its lytic ability (R(2) = 0.98). Taken with molecular dynamic simulations, these results suggest that maximin H5 possesses membranolytic activity, primarily involving bilayer insertion of its strongly hydrophobic N-terminal region. However, this region was predicted to form multiple hydrogen bonds with phosphate and ammonium groups within PE head-groups, which in concert with charge-charge interactions anchor the peptide to the surface of E. coli membranes, inhibiting its membranolytic action.
Collapse
Affiliation(s)
- Sarah R Dennison
- School of Pharmacy and Biomedical Sciences, †School of Forensic and Investigative Sciences, and ‡School of Computing, Engineering and Physical Sciences, University of Central Lancashire , Preston, PR1 2HE, U.K
| | | | | | | | | | | |
Collapse
|
131
|
Parsons JB, Rock CO. Bacterial lipids: metabolism and membrane homeostasis. Prog Lipid Res 2013; 52:249-76. [PMID: 23500459 PMCID: PMC3665635 DOI: 10.1016/j.plipres.2013.02.002] [Citation(s) in RCA: 298] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 02/27/2013] [Accepted: 02/28/2013] [Indexed: 11/29/2022]
Abstract
Membrane lipid homeostasis is a vital facet of bacterial cell physiology. For decades, research in bacterial lipid synthesis was largely confined to the Escherichia coli model system. This basic research provided a blueprint for the biochemistry of lipid metabolism that has largely defined the individual steps in bacterial fatty acid and phospholipids synthesis. The advent of genomic sequencing has revealed a surprising amount of diversity in the genes, enzymes and genetic organization of the components responsible for bacterial lipid synthesis. Although the chemical steps in fatty acid synthesis are largely conserved in bacteria, there are surprising differences in the structure and cofactor requirements for the enzymes that perform these reactions in Gram-positive and Gram-negative bacteria. This review summarizes how the explosion of new information on the diversity of biochemical and genetic regulatory mechanisms has impacted our understanding of bacterial lipid homeostasis. The potential and problems of developing therapeutics that block pathogen phospholipid synthesis are explored and evaluated. The study of bacterial lipid metabolism continues to be a rich source for new biochemistry that underlies the variety and adaptability of bacterial life styles.
Collapse
Affiliation(s)
- Joshua B Parsons
- Department of Infectious Diseases, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | | |
Collapse
|
132
|
Abstract
Molecular mimicry of host proteins is a common strategy adopted by bacterial pathogens to interfere with and exploit host processes. Despite the availability of pathogen genomes, few studies have attempted to predict virulence-associated mimicry relationships directly from genomic sequences. Here, we analyzed the proteomes of 62 pathogenic and 66 non-pathogenic bacterial species, and screened for the top pathogen-specific or pathogen-enriched sequence similarities to human proteins. The screen identified approximately 100 potential mimicry relationships including well-characterized examples among the top-scoring hits (e.g., RalF, internalin, yopH, and others), with about 1/3 of predicted relationships supported by existing literature. Examination of homology to virulence factors, statistically enriched functions, and comparison with literature indicated that the detected mimics target key host structures (e.g., extracellular matrix, ECM) and pathways (e.g., cell adhesion, lipid metabolism, and immune signaling). The top-scoring and most widespread mimicry pattern detected among pathogens consisted of elevated sequence similarities to ECM proteins including collagens and leucine-rich repeat proteins. Unexpectedly, analysis of the pathogen counterparts of these proteins revealed that they have evolved independently in different species of bacterial pathogens from separate repeat amplifications. Thus, our analysis provides evidence for two classes of mimics: complex proteins such as enzymes that have been acquired by eukaryote-to-pathogen horizontal transfer, and simpler repeat proteins that have independently evolved to mimic the host ECM. Ultimately, computational detection of pathogen-specific and pathogen-enriched similarities to host proteins provides insights into potentially novel mimicry-mediated virulence mechanisms of pathogenic bacteria.
Collapse
Affiliation(s)
- Andrew C Doxey
- Department of Biology, University of Waterloo, Waterloo, ON, Canada.
| | | |
Collapse
|
133
|
Edgcomb VP, Bernhard JM, Beaudoin D, Pruss S, Welander PV, Schubotz F, Mehay S, Gillespie AL, Summons RE. Molecular indicators of microbial diversity in oolitic sands of Highborne Cay, Bahamas. GEOBIOLOGY 2013; 11:234-251. [PMID: 23398981 DOI: 10.1111/gbi.12029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Accepted: 01/04/2013] [Indexed: 06/01/2023]
Abstract
Microbialites (stromatolites and thrombolites) are mineralized mat structures formed via the complex interactions of diverse microbial-mat communities. At Highborne Cay, in the Bahamas, the carbonate component of these features is mostly comprised of ooids. These are small, spherical to ellipsoidal grains characterized by concentric layers of calcium carbonate and organic matter and these sand-sized particles are incorporated with the aid of extra-cellular polymeric substances (EPS), into the matrix of laminated stromatolites and clotted thrombolite mats. Here, we present a comparison of the bacterial diversity within oolitic sand samples and bacterial diversity previously reported in thrombolitic and stromatolitic mats of Highborne Cay based on analysis of clone libraries of small subunit ribosomal RNA gene fragments and lipid biomarkers. The 16S-rRNA data indicate that the overall bacterial diversity within ooids is comparable to that found within thrombolites and stromatolites of Highborne Cay, and this significant overlap in taxonomic groups suggests that ooid sands may be a source for much of the bacterial diversity found in the local microbialites. Cyanobacteria were the most diverse taxonomic group detected, followed by Alphaproteobacteria, Gammaproteobacteria, Planctomyces, Deltaproteobacteria, and several other groups also found in mat structures. The distributions of intact polar lipids, the fatty acids derived from them, and bacteriohopanepolyols provide broad general support for the bacterial diversity identified through analysis of nucleic acid clone libraries.
Collapse
Affiliation(s)
- V P Edgcomb
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
134
|
D'Avanzo N, McCusker EC, Powl AM, Miles AJ, Nichols CG, Wallace BA. Differential lipid dependence of the function of bacterial sodium channels. PLoS One 2013; 8:e61216. [PMID: 23579615 PMCID: PMC3620320 DOI: 10.1371/journal.pone.0061216] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 03/08/2013] [Indexed: 12/13/2022] Open
Abstract
The lipid bilayer is important for maintaining the integrity of cellular compartments and plays a vital role in providing the hydrophobic and charged interactions necessary for membrane protein structure, conformational flexibility and function. To directly assess the lipid dependence of activity for voltage-gated sodium channels, we compared the activity of three bacterial sodium channel homologues (NaChBac, NavMs, and NavSp) by cumulative (22)Na(+) uptake into proteoliposomes containing a 3∶1 ratio of 1-palmitoyl 2-oleoyl phosphatidylethanolamine and different "guest" glycerophospholipids. We observed a unique lipid profile for each channel tested. NavMs and NavSp showed strong preference for different negatively-charged lipids (phosphatidylinositol and phosphatidylglycerol, respectively), whilst NaChBac exhibited a more modest variation with lipid type. To investigate the molecular bases of these differences we used synchrotron radiation circular dichroism spectroscopy to compare structures in liposomes of different composition, and molecular modeling and electrostatics calculations to rationalize the functional differences seen. We then examined pore-only constructs (with voltage sensor subdomains removed) and found that in these channels the lipid specificity was drastically reduced, suggesting that the specific lipid influences on voltage-gated sodium channels arise primarily from their abilities to interact with the voltage-sensing subdomains.
Collapse
Affiliation(s)
- Nazzareno D'Avanzo
- Department of Physiology and GEPROM (Group d'étude des Proteins Membranaires), Université de Montréal, Montréal, Québec, Canada
- Department of Cell Biology and Physiology and Center for Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Emily C. McCusker
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom
| | - Andrew M. Powl
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom
| | - Andrew J. Miles
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom
| | - Colin G. Nichols
- Department of Cell Biology and Physiology and Center for Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail: (CN); (BW)
| | - B. A. Wallace
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom
- * E-mail: (CN); (BW)
| |
Collapse
|
135
|
Yu X, Yang X, Horte S, Kizhakkedathu JN, Brooks DE. ATRP synthesis of poly(2-(methacryloyloxy)ethyl choline phosphate): a multivalent universal biomembrane adhesive. Chem Commun (Camb) 2013; 49:6831-3. [DOI: 10.1039/c3cc41895b] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
136
|
Identification and characterization of a high-affinity choline uptake system of Brucella abortus. J Bacteriol 2012; 195:493-501. [PMID: 23161032 DOI: 10.1128/jb.01929-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phosphatidylcholine (PC), a common phospholipid of the eukaryotic cell membrane, is present in the cell envelope of the intracellular pathogen Brucella abortus, the etiological agent of bovine brucellosis. In this pathogen, the biosynthesis of PC proceeds mainly through the phosphatidylcholine synthase pathway; hence, it relies on the presence of choline in the milieu. These observations imply that B. abortus encodes an as-yet-unknown choline uptake system. Taking advantage of the requirement of choline uptake for PC synthesis, we devised a method that allowed us to identify a homologue of ChoX, the high-affinity periplasmic binding protein of the ABC transporter ChoXWV. Disruption of the choX gene completely abrogated PC synthesis at low choline concentrations in the medium, thus indicating that it is a high-affinity transporter needed for PC synthesis via the PC synthase (PCS) pathway. However, the synthesis of PC was restored when the mutant was incubated in media with higher choline concentrations, suggesting the presence of an alternative low-affinity choline uptake activity. By means of a fluorescence-based equilibrium-binding assay and using the kinetics of radiolabeled choline uptake, we show that ChoX binds choline with an extremely high affinity, and we also demonstrate that its activity is inhibited by increasing choline concentrations. Cell infection assays indicate that ChoX activity is required during the first phase of B. abortus intracellular traffic, suggesting that choline concentrations in the early and intermediate Brucella-containing vacuoles are limited. Altogether, these results suggest that choline transport and PC synthesis are strictly regulated in B. abortus.
Collapse
|
137
|
Ridilla M, Narayanan A, Bolin JT, Yernool DA. Identification of the dimer interface of a bacterial Ca(2+)/H(+) antiporter. Biochemistry 2012; 51:9603-11. [PMID: 23134204 DOI: 10.1021/bi3012109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Members of the calcium/cation antiporter superfamily, including the cardiac sodium/calcium exchangers, are secondary active transporters that play an essential role in cellular Ca(2+) homeostasis. A notable feature of this group of transporters is the high levels of sequence similarity in relatively short sequences constituting the functionally important α-1 and α-2 regions in contrast to relatively lower degrees of similarity in the extended adjoining sequences. This suggests a similar structure and function of core transport machinery but possible differences in topology and/or oligomerization, a topic that has not been adequately addressed. Here we present the first example of purification of a bacterial member of this superfamily (CAX(CK31)) and analyze its quaternary structure. Purification of CAX(CK31) required the presence of a choline headgroup-containing detergent or lipid to yield stable preparations of the monomeric transporter. H(+)-driven Ca(2+) transport was demonstrated by reconstituting purified CAX(CK31) into liposomes. Dimeric CAX(CK31) could be isolated by manipulation of detergent micelles. Dimer formation was shown to be dependent on micelle composition as well as protein concentration. Furthermore, we establish that CAX(CK31) forms dimers in the membrane by analysis of cross-linked proteins. Using a dimeric homology model derived from the monomeric structure of the archaeal NCX homologue (Protein Data Bank entry 3V5U ), we introduced cysteine residues and through cross-linking experiments established the role of transmembrane helices 2 and 6 in the putative dimer interface.
Collapse
Affiliation(s)
- Marc Ridilla
- Department of Biological Sciences, Purdue University, 240 South Martin Jischke Drive, West Lafayette, IN 47906, USA
| | | | | | | |
Collapse
|
138
|
Farine L, Bütikofer P. The ins and outs of phosphatidylethanolamine synthesis in Trypanosoma brucei. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:533-42. [PMID: 23010476 DOI: 10.1016/j.bbalip.2012.09.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 09/07/2012] [Accepted: 09/16/2012] [Indexed: 12/23/2022]
Abstract
Phospholipids are not only major building blocks of biological membranes but fulfill a wide range of critical functions that are often widely unrecognized. In this review, we focus on phosphatidylethanolamine, a major glycerophospholipid class in eukaryotes and bacteria, which is involved in many unexpected biological processes. We describe (i) the ins, i.e. the substrate sources and biochemical reactions involved in phosphatidylethanolamine synthesis, and (ii) the outs, i.e. the different roles of phosphatidylethanolamine and its involvement in various cellular events. We discuss how the protozoan parasite, Trypanosoma brucei, has contributed and may contribute in the future as eukaryotic model organism to our understanding of phosphatidylethanolamine homeostasis. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism.
Collapse
Affiliation(s)
- Luce Farine
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012 Bern, Switzerland.
| | | |
Collapse
|
139
|
Geiger O, López-Lara IM, Sohlenkamp C. Phosphatidylcholine biosynthesis and function in bacteria. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:503-13. [PMID: 22922101 DOI: 10.1016/j.bbalip.2012.08.009] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 08/10/2012] [Accepted: 08/13/2012] [Indexed: 02/03/2023]
Abstract
Phosphatidylcholine (PC) is the major membrane-forming phospholipid in eukaryotes and is estimated to be present in about 15% of the domain Bacteria. Usually, PC can be synthesized in bacteria by either of two pathways, the phospholipid N-methylation (Pmt) pathway or the phosphatidylcholine synthase (Pcs) pathway. The three subsequent enzymatic methylations of phosphatidylethanolamine are performed by a single phospholipid N-methyltransferase in some bacteria whereas other bacteria possess multiple phospholipid N-methyltransferases each one performing one or several distinct methylation steps. Phosphatidylcholine synthase condenses choline directly with CDP-diacylglycerol to form CMP and PC. Like in eukaryotes, bacterial PC also functions as a biosynthetic intermediate during the formation of other biomolecules such as choline, diacylglycerol, or diacylglycerol-based phosphorus-free membrane lipids. Bacterial PC may serve as a specific recognition molecule but it affects the physicochemical properties of bacterial membranes as well. This article is part of a Special Issue entitled Phospholipids and Phospholipid Metabolism.
Collapse
Affiliation(s)
- Otto Geiger
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad s/n, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico.
| | | | | |
Collapse
|
140
|
de Freitas-Junior PRG, Catta-Preta CMC, Andrade IDS, Cavalcanti DP, de Souza W, Einicker-Lamas M, Motta MCM. Effects of miltefosine on the proliferation, ultrastructure, and phospholipid composition of Angomonas deanei, a trypanosomatid protozoan that harbors a symbiotic bacterium. FEMS Microbiol Lett 2012; 333:129-37. [PMID: 22651853 DOI: 10.1111/j.1574-6968.2012.02607.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 05/22/2012] [Accepted: 05/22/2012] [Indexed: 11/28/2022] Open
Abstract
Some trypanosomatids, such as Angomonas deanei formerly named as Crithidia deanei, present an obligatory intracellular bacterium, which maintains a mutualistic relationship with the host. Phosphatidylcholine (PC) is the major phospholipid in eukaryotes and an essential component of cell membranes playing structural, biochemical, and physiological roles. However, in prokaryotes, PC is present only in those species closely associated with eukaryotes, either in symbiotic or pathogenic interactions. In trypanosomatids, the endosymbiont envelope is composed by a reduced cell wall and by two membrane units that lack sterols and present cardiolipin (CL) and PC as the major phospholipids. In this study, we tested the effects of miltefosine in A. deanei proliferation, as well as, on the ultrastrucuture and phospholipid composition considering that this drug inhibits the CTP-phosphocholine cytidyltransferase (CCT), a key enzyme in the PC biosynthesis. Besides the low effect of miltefosine in cellular proliferation, treated protozoa presented ultrastructural alterations such as plasma membrane shedding and blebbing, mitochondrial swelling, and convolutions of the endosymbiont envelope. The use of (32) Pi as a tracer revealed that the production of PC, CL, and phosphatidylethanolamine decreased while phosphatidylinositol production remained stable. Mitochondrion and symbiont fractions obtained from protozoa treated with miltefosine also presented a decrease in phospholipid production, reinforcing the idea that an intensive metabolic exchange occurs between the host trypanosomatid and structures of symbiotic origin.
Collapse
Affiliation(s)
- Paulo R G de Freitas-Junior
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | | | | | | | | | | |
Collapse
|
141
|
Boeris PS, Lucchesi GI. The phosphatidylcholine synthase of Pseudomonas putida A ATCC 12633 is responsible for the synthesis of phosphatidylcholine, which acts as a temporary reservoir for Al3+. Microbiology (Reading) 2012; 158:1249-1257. [DOI: 10.1099/mic.0.054072-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Paola S. Boeris
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Gloria I. Lucchesi
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| |
Collapse
|
142
|
Solís-Oviedo RL, Martínez-Morales F, Geiger O, Sohlenkamp C. Functional and topological analysis of phosphatidylcholine synthase from Sinorhizobium meliloti. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:573-81. [DOI: 10.1016/j.bbalip.2012.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 01/17/2012] [Accepted: 01/30/2012] [Indexed: 10/14/2022]
|
143
|
Yu X, Liu Z, Janzen J, Chafeeva I, Horte S, Chen W, Kainthan RK, Kizhakkedathu JN, Brooks DE. Polyvalent choline phosphate as a universal biomembrane adhesive. NATURE MATERIALS 2012; 11:468-476. [PMID: 22426460 DOI: 10.1038/nmat3272] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 02/07/2012] [Indexed: 05/31/2023]
Abstract
Phospholipids in the cell membranes of all eukaryotic cells contain phosphatidyl choline (PC) as the headgroup. Here we show that hyperbranched polyglycerols (HPGs) decorated with the 'PC-inverse' choline phosphate (CP) in a polyvalent fashion can electrostatically bind to a variety of cell membranes and to PC-containing liposomes, the binding strength depending on the number density of CP groups per macromolecule. We also show that HPG-CPs can cause cells to adhere with varying affinity to other cells, and that binding can be reversed by subsequent exposure to low molecular weight HPGs carrying small numbers of PCs. Moreover, PC-rich membranes adsorb and rapidly internalize fluorescent HPG-CP but not HPG-PC molecules, which suggests that HPG-CPs could be used as drug-delivery agents. CP-decorated polymers should find broad use, for instance as tissue sealants and in the self-assembly of lipid nanostructures.
Collapse
Affiliation(s)
- Xifei Yu
- Centre for Blood Research, 2350 Health Sciences Mall, University of British Columbia, Vancouver V6T 1Z3, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
144
|
Physiological and proteomic adaptation of "Aromatoleum aromaticum" EbN1 to low growth rates in benzoate-limited, anoxic chemostats. J Bacteriol 2012; 194:2165-80. [PMID: 22366417 DOI: 10.1128/jb.06519-11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
"Aromatoleum aromaticum" EbN1 was cultivated at different growth rates in benzoate-limited chemostats under nitrate-reducing conditions. Physiological characteristics, proteome dynamics, phospholipid-linked fatty acid (PLFA) composition, and poly(3-hydroxybutyrate) (PHB) content were analyzed in steady-state cells at low (μ(low)) (0.036 h(-1)), medium (μ(med)) (0.108 h(-1)), and high (μ(high)) (0.180 h(-1)) growth rates. A positive correlation to growth rate was observed for cellular parameters (cell size, and DNA and protein contents). The free energy consumed for biomass formation steadily increased with growth rate. In contrast, the energy demand for maintenance increased only from μ(low) to μ(med) and then remained constant until μ(high). The most comprehensive proteomic changes were observed at μ(low) compared to μ(high). Uniformly decreased abundances of protein components of the anaerobic benzoyl coenzyme A (benzoyl-CoA) pathway, central carbon metabolism, and information processing agree with a general deceleration of benzoate metabolism and cellular processes in response to slow growth. In contrast, increased abundances were observed at μ(low) for diverse catabolic proteins and components of uptake systems in the absence of the respective substrate (aromatic or aliphatic compounds) and for proteins involved in stress responses. This potential catabolic versatility and stress defense during slow growth may be interpreted as preparation for future needs.
Collapse
|
145
|
Li PY, Xie BB, Zhang XY, Qin QL, Dang HY, Wang XM, Chen XL, Yu J, Zhang YZ. Genetic structure of three fosmid-fragments encoding 16S rRNA genes of the Miscellaneous Crenarchaeotic Group (MCG): implications for physiology and evolution of marine sedimentary archaea. Environ Microbiol 2011; 14:467-79. [DOI: 10.1111/j.1462-2920.2011.02637.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
146
|
Müller FD, Beck S, Strauch E, Linscheid MW. Bacterial Predators Possess Unique Membrane Lipid Structures. Lipids 2011; 46:1129-40. [DOI: 10.1007/s11745-011-3614-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 09/09/2011] [Indexed: 11/29/2022]
|
147
|
He H, Wu B, Xiong M, Li Y, Wu W, Wang X. Gene cloning, structural gene and promoter identification, and active assay of the phosphatidylcholine synthase of Pseudomonas sp. strain 593. Can J Microbiol 2011; 57:785-94. [DOI: 10.1139/w11-073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pseudomonas sp. strain 593, a soil bacterium, is able to use exogenous choline to synthesize phosphatidylcholine via phosphatidylcholine synthase (Pcs). A 2020 bp DNA fragment that hybridized to a Pcs probe was cloned. This fragment contained a large open reading frame (ORF) with two potential ATG start sites that would encode for 293 and 231 amino acid proteins. Fragments containing the two ORFs encoded Pcs when they were inserted into the expression vector pET23a and expressed under the control of the T7 promoter in Escherichia coli BL21(DE3) pLysS. However, when the two ORFs were inserted into the cloning vector pMD18-T and expressed without control of the plasmid promoter in E. coli DH5α, only the larger clone exhibited Pcs activity. This suggested that the larger fragment contained a native promoter driving expression of the smaller ORF. A promoter activity assay, in which DNA fragments were inserted into the promoter-probe plasmid pCB182 and β-galactosidase activity of E. coli transformants was tested, demonstrated that a promoter is indeed present in the DNA region. All results together indicate that the 696 bp ORF, not the larger 897 bp ORF, encodes the Pcs in Pseudomonas sp. strain 593 and carries a promoter in front of its 5′ terminus.
Collapse
Affiliation(s)
- Huoguang He
- The Faculty of Life Sciences, Hubei University, 368 Youyi Road, Wuchang, Wuhan 430062, People’s Republic of China
| | - Bin Wu
- The Faculty of Life Sciences, Hubei University, 368 Youyi Road, Wuchang, Wuhan 430062, People’s Republic of China
| | - Min Xiong
- The Faculty of Life Sciences, Hubei University, 368 Youyi Road, Wuchang, Wuhan 430062, People’s Republic of China
| | - Yang Li
- The Faculty of Life Sciences, Hubei University, 368 Youyi Road, Wuchang, Wuhan 430062, People’s Republic of China
| | - Wenhua Wu
- The Faculty of Life Sciences, Hubei University, 368 Youyi Road, Wuchang, Wuhan 430062, People’s Republic of China
| | - Xingguo Wang
- The Faculty of Life Sciences, Hubei University, 368 Youyi Road, Wuchang, Wuhan 430062, People’s Republic of China
| |
Collapse
|
148
|
De Luca G, Barakat M, Ortet P, Fochesato S, Jourlin-Castelli C, Ansaldi M, Py B, Fichant G, Coutinho PM, Voulhoux R, Bastien O, Maréchal E, Henrissat B, Quentin Y, Noirot P, Filloux A, Méjean V, DuBow MS, Barras F, Barbe V, Weissenbach J, Mihalcescu I, Verméglio A, Achouak W, Heulin T. The cyst-dividing bacterium Ramlibacter tataouinensis TTB310 genome reveals a well-stocked toolbox for adaptation to a desert environment. PLoS One 2011; 6:e23784. [PMID: 21912644 PMCID: PMC3164672 DOI: 10.1371/journal.pone.0023784] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 07/25/2011] [Indexed: 11/22/2022] Open
Abstract
Ramlibacter tataouinensis TTB310(T) (strain TTB310), a betaproteobacterium isolated from a semi-arid region of South Tunisia (Tataouine), is characterized by the presence of both spherical and rod-shaped cells in pure culture. Cell division of strain TTB310 occurs by the binary fission of spherical "cyst-like" cells ("cyst-cyst" division). The rod-shaped cells formed at the periphery of a colony (consisting mainly of cysts) are highly motile and colonize a new environment, where they form a new colony by reversion to cyst-like cells. This unique cell cycle of strain TTB310, with desiccation tolerant cyst-like cells capable of division and desiccation sensitive motile rods capable of dissemination, appears to be a novel adaptation for life in a hot and dry desert environment. In order to gain insights into strain TTB310's underlying genetic repertoire and possible mechanisms responsible for its unusual lifestyle, the genome of strain TTB310 was completely sequenced and subsequently annotated. The complete genome consists of a single circular chromosome of 4,070,194 bp with an average G+C content of 70.0%, the highest among the Betaproteobacteria sequenced to date, with total of 3,899 predicted coding sequences covering 92% of the genome. We found that strain TTB310 has developed a highly complex network of two-component systems, which may utilize responses to light and perhaps a rudimentary circadian hourglass to anticipate water availability at the dew time in the middle/end of the desert winter nights and thus direct the growth window to cyclic water availability times. Other interesting features of the strain TTB310 genome that appear to be important for desiccation tolerance, including intermediary metabolism compounds such as trehalose or polyhydroxyalkanoate, and signal transduction pathways, are presented and discussed.
Collapse
Affiliation(s)
- Gilles De Luca
- CEA, Lab Ecol Microbienne Rhizosphere & Environm Extre, iBEB, DSV, Saint-Paul-lez-Durance, France.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
149
|
Choline uptake in Agrobacterium tumefaciens by the high-affinity ChoXWV transporter. J Bacteriol 2011; 193:5119-29. [PMID: 21803998 DOI: 10.1128/jb.05421-11] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Agrobacterium tumefaciens is a facultative phytopathogen that causes crown gall disease. For successful plant transformation A. tumefaciens requires the membrane lipid phosphatidylcholine (PC), which is produced via the methylation and the PC synthase (Pcs) pathways. The latter route is dependent on choline. Although choline uptake has been demonstrated in A. tumefaciens, the responsible transporter(s) remained elusive. In this study, we identified the first choline transport system in A. tumefaciens. The ABC-type choline transporter is encoded by the chromosomally located choXWV operon (ChoX, binding protein; ChoW, permease; and ChoV, ATPase). The Cho system is not critical for growth and PC synthesis. However, [14C]choline uptake is severely reduced in A. tumefaciens choX mutants. Recombinant ChoX is able to bind choline with high affinity (equilibrium dissociation constant [KD] of ≈2 μM). Since other quaternary amines are bound by ChoX with much lower affinities (acetylcholine, KD of ≈80 μM; betaine, KD of ≈470 μM), the ChoXWV system functions as a high-affinity transporter with a preference for choline. Two tryptophan residues (W40 and W87) located in the predicted ligand-binding pocket are essential for choline binding. The structural model of ChoX built on Sinorhizobium meliloti ChoX resembles the typical structure of substrate binding proteins with a so-called "Venus flytrap mechanism" of substrate binding.
Collapse
|
150
|
Bauersachs T, Compaoré J, Severin I, Hopmans EC, Schouten S, Stal LJ, Sinninghe Damsté JS. Diazotrophic microbial community of coastal microbial mats of the southern North Sea. GEOBIOLOGY 2011; 9:349-359. [PMID: 21535363 DOI: 10.1111/j.1472-4669.2011.00280.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The diazotrophic community in microbial mats growing along the shore of the North Sea barrier island Schiermonnikoog (The Netherlands) was studied using microscopy, lipid biomarkers, stable carbon (δ(13) C(TOC) ) and nitrogen (δ(15) N) isotopes as well as by constructing and analyzing 16S rRNA gene libraries. Depending on their position on the littoral gradient, two types of mats were identified, which showed distinct differences regarding the structure, development and composition of the microbial community. Intertidal microbial mats showed a low species diversity with filamentous non-heterocystous Cyanobacteria providing the main mat structure. In contrast, supratidal microbial mats showed a distinct vertical zonation and a high degree of species diversity. Morphotypes of non-heterocystous Cyanobacteria were recognized as the main structural component in these mats. In addition, unicellular Cyanobacteria were frequently observed, whereas filamentous heterocystous Cyanobacteria occurred only in low numbers. Besides the apparent visual dominance of cyanobacterial morphotpyes, 16S rRNA gene libraries indicated that both microbial mat types also included members of the Proteobacteria and the Cytophaga-Flavobacterium-Bacteroides group as well as diatoms. Bulk δ(15) N isotopes of the microbial mats ranged from +6.1‰ in the lower intertidal to -1.2‰ in the supratidal zone, indicating a shift from predominantly nitrate utilization to nitrogen fixation along the littoral gradient. This conclusion was supported by the presence of heterocyst glycolipids, representing lipid biomarkers for nitrogen-fixing heterocystous Cyanobacteria, in supratidal but not in intertidal microbial mats. The availability of combined nitrogen species might thus be a key factor in controlling and regulating the distribution of the diazotrophic microbial community of Schiermonnikoog.
Collapse
Affiliation(s)
- T Bauersachs
- Department of Marine Organic Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, The Netherlands
| | | | | | | | | | | | | |
Collapse
|