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Demey LM, Sinha R, DiRita VJ. An essential host dietary fatty acid promotes TcpH inhibition of TcpP proteolysis promoting virulence gene expression in Vibrio cholerae. mBio 2024:e0072124. [PMID: 38958446 DOI: 10.1128/mbio.00721-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 05/03/2024] [Indexed: 07/04/2024] Open
Abstract
Vibrio cholerae is a Gram-negative gastrointestinal pathogen responsible for the diarrheal disease cholera. Expression of key virulence factors, cholera toxin and toxin-coregulated pilus, is regulated directly by ToxT and indirectly by two transmembrane transcription regulators (TTRs), ToxR and TcpP, that promote the expression of toxT. TcpP abundance and activity are controlled by TcpH, a single-pass transmembrane protein, which protects TcpP from a two-step proteolytic process known as regulated intramembrane proteolysis (RIP). The mechanism of TcpH-mediated protection of TcpP represents a major gap in our understanding of V. cholerae pathogenesis. The absence of tcpH leads to unimpeded degradation of TcpP in vitro and a colonization defect in a neonate mouse model of V. cholerae colonization. Here, we show that TcpH protects TcpP from RIP via direct interaction. We also demonstrate that α-linolenic acid, a dietary fatty acid, promotes TcpH-dependent inhibition of RIP via co-association of TcpP and TcpH molecules within detergent-resistant membranes (DRMs) in a mechanism requiring the TcpH transmembrane domain. Taken together, our data support a model where V. cholerae cells use exogenous α-linolenic acid to remodel the phospholipid bilayer in vivo, leading to co-association of TcpP and TcpH within DRMs where RIP of TcpP is inhibited by TcpH, thereby promoting V. cholerae pathogenicity. IMPORTANCE Vibrio cholerae continues to pose a significant global burden on health and an alternative therapeutic approach is needed, due to evolving multidrug resistance strains. Transcription of toxT, stimulated by TcpP and ToxR, is essential for V. cholerae pathogenesis. Our results show that TcpP, one of the major regulators of toxT gene expression, is protected from proteolysis by TcpH, via direct interaction. Furthermore, we identified a gut metabolite, α-linolenic acid, that stimulates the co-association of TcpP and TcpH within detergent-resistant membranes (also known as lipid-ordered membrane domains), thereby supporting TcpH-dependent antagonism of TcpP proteolysis. Data presented here extend our knowledge of RIP, virulence gene regulation in V. cholerae, and, to the best of our knowledge, provides the first evidence that lipid-ordered membranes exist within V. cholerae. The model presented here also suggests that TTRs, common among bacteria and archaea, and co-component signal transduction systems present in Enterobacteria, could also be influenced similarly.
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Affiliation(s)
- Lucas M Demey
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Ritam Sinha
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Victor J DiRita
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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2
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Refai MY, Elazzazy AM, Desouky SE, Abu-Elghait M, Fayed EA, Alajel SM, Alajlan AA, Albureikan MO, Nakayama J. Interception of Epoxide ring to quorum sensing system in Enterococcus faecalis and Staphylococcus aureus. AMB Express 2023; 13:126. [PMID: 37946062 PMCID: PMC10636001 DOI: 10.1186/s13568-023-01633-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023] Open
Abstract
Quorum sensing inhibitor (QSI) has been attracting attention as anti-virulence agent which disarms pathogens of their virulence rather than killing them. QSI marking cyclic peptide-mediated QS in Gram-positive bacteria is an effective tool to overcome the crisis of antibiotic-dependent chemotherapy due to the emergence of drug resistance strain, e.g., methicillin resistant Staphylococcus aureus (MRSA) and Vancomycin resistant Enterococci (VRE). From a semi-large-scale screening thus far carried out, two Epoxide compounds, Ambuic acid and Synerazol, have been found to efficiently block agr and fsr QS systems, suggesting that the Epoxide group is involved in the mode of action of these QSIs. To address this notion, known natural Epoxide compounds, Cerulenin and Fosfomycin were examined for QSI activity for the agr and fsr systems in addition to in silico and SAR studies. As a result, most of investigated Epoxide containing antibiotics correlatively interfere with QSI activity for the agr and fsr systems under sublethal concentrations.
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Affiliation(s)
- Mohammed Y Refai
- Department of Biological Science, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Ahmed M Elazzazy
- Department of Biological Science, College of Science, University of Jeddah, Jeddah, Saudi Arabia
| | - Said E Desouky
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 819-0395, Fukuoka, Japan
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Cairo, Egypt
| | - Mohammed Abu-Elghait
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Cairo, Egypt.
| | - Eman A Fayed
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy (Girls), Al-Azhar University, 11754, Cairo, Egypt
| | - Sulaiman M Alajel
- Reference Laboratory for Microbiology, Executive Department of Reference Laboratories, Research and Laboratories Sector, Saudi Food and Drug Authority (SFDA), Riyadh, Saudi Arabia
| | - Abdullah A Alajlan
- Microbial Identification Division, Reference Laboratory for Microbiology, Executive Department of Reference Laboratories, Research and Laboratories Sector, Saudi Food and Drug Authority (SFDA), Riyadh, Saudi Arabia
| | - Mona O Albureikan
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, 21589, Jeddah, Saudi Arabia
| | - Jiro Nakayama
- Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 819-0395, Fukuoka, Japan
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3
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Zee BM, Poels KE, Yao CH, Kawabata KC, Wu G, Duy C, Jacobus WD, Senior E, Endress JE, Jambhekar A, Lovitch SB, Ma J, Dhall A, Harris IS, Blanco MA, Sykes DB, Licht JD, Weinstock DM, Melnick A, Haigis MC, Michor F, Shi Y. Combined epigenetic and metabolic treatments overcome differentiation blockade in acute myeloid leukemia. iScience 2021; 24:102651. [PMID: 34151238 PMCID: PMC8192696 DOI: 10.1016/j.isci.2021.102651] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/03/2020] [Accepted: 05/24/2021] [Indexed: 02/07/2023] Open
Abstract
A hallmark of acute myeloid leukemia (AML) is the inability of self-renewing malignant cells to mature into a non-dividing terminally differentiated state. This differentiation block has been linked to dysregulation of multiple cellular processes, including transcriptional, chromatin, and metabolic regulation. The transcription factor HOXA9 and the histone demethylase LSD1 are examples of such regulators that promote differentiation blockade in AML. To identify metabolic targets that interact with LSD1 inhibition to promote myeloid maturation, we screened a small molecule library to identify druggable substrates. We found that differentiation caused by LSD1 inhibition is enhanced by combined perturbation of purine nucleotide salvage and de novo lipogenesis pathways, and identified multiple lines of evidence to support the specificity of these pathways and suggest a potential basis of how perturbation of these pathways may interact synergistically to promote myeloid differentiation. In sum, these findings suggest potential drug combination strategies in the treatment of AML.
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Affiliation(s)
- Barry M. Zee
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
- Ludwig Institute for Cancer Research, Oxford University, OX3 7DQ, UK
| | - Kamrine E. Poels
- Department of Data Science, Dana Farber Cancer Institute, Boston, MA 02215, USA
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Cong-Hui Yao
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Kimihito C. Kawabata
- Division of Hematology-Medical Oncology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Gongwei Wu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Cihangir Duy
- Cancer Signaling and Epigenetics Program, Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
- Cancer Epigenetics Institute, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - William D. Jacobus
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Elizabeth Senior
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | | | - Ashwini Jambhekar
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
- The Ludwig Center at Harvard, Boston, MA 02115, USA
| | - Scott B. Lovitch
- Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Jiexian Ma
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Abhinav Dhall
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
- Ludwig Institute for Cancer Research, Oxford University, OX3 7DQ, UK
| | - Isaac S. Harris
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - M. Andres Blanco
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - David B. Sykes
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Jonathan D. Licht
- Division of Hematology and Oncology, University of Florida Health Care Center, Gainesville, FL 32610, USA
| | - David M. Weinstock
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Cancer Biology Program, Broad Institute of MIT and Harvard University, Cambridge, MA 02142, USA
| | - Ari Melnick
- Division of Hematology-Medical Oncology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Marcia C. Haigis
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Franziska Michor
- Department of Data Science, Dana Farber Cancer Institute, Boston, MA 02215, USA
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
- The Ludwig Center at Harvard, Boston, MA 02115, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
- The Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
- The Center for Cancer Evolution, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Yang Shi
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
- Ludwig Institute for Cancer Research, Oxford University, OX3 7DQ, UK
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4
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Kalkreuter E, Keeler AM, Malico AA, Bingham KS, Gayen AK, Williams GJ. Development of a Genetically Encoded Biosensor for Detection of Polyketide Synthase Extender Units in Escherichia coli. ACS Synth Biol 2019; 8:1391-1400. [PMID: 31134799 PMCID: PMC6915837 DOI: 10.1021/acssynbio.9b00078] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The scaffolds of polyketides are constructed via assembly of extender units based on malonyl-CoA and its derivatives that are substituted at the C2-position with diverse chemical functionality. Subsequently, a transcription-factor-based biosensor for malonyl-CoA has proven to be a powerful tool for detecting malonyl-CoA, facilitating the dynamic regulation of malonyl-CoA biosynthesis and guiding high-throughput engineering of malonyl-CoA-dependent processes. Yet, a biosensor for the detection of malonyl-CoA derivatives has yet to be reported, severely restricting the application of high-throughput synthetic biology approaches to engineering extender unit biosynthesis and limiting the ability to dynamically regulate the biosynthesis of polyketide products that are dependent on such α-carboxyacyl-CoAs. Herein, the FapR biosensor was re-engineered and optimized for a range of mCoA concentrations across a panel of E. coli strains. The effector specificity of FapR was probed by cell-free transcription-translation, revealing that a variety of non-native and non-natural acyl-thioesters are FapR effectors. This FapR promiscuity proved sufficient for the detection of the polyketide extender unit methylmalonyl-CoA in E. coli, providing the first reported genetically encoded biosensor for this important metabolite. As such, the previously unknown broad effector promiscuity of FapR provides a platform to develop new tools and approaches that can be leveraged to overcome limitations of pathways that construct diverse α-carboxyacyl-CoAs and those that are dependent on them, including biofuels, antibiotics, anticancer drugs, and other value-added products.
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Affiliation(s)
- Edward Kalkreuter
- Department of Chemistry, NC State University, Raleigh, North Carolina 27695, United States
- Comparative Medicine Institute, NC State University, Raleigh, North Carolina 27695, United States
- Present address: Department of Chemistry, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Aaron M. Keeler
- Department of Chemistry, NC State University, Raleigh, North Carolina 27695, United States
| | - Alexandra A. Malico
- Department of Chemistry, NC State University, Raleigh, North Carolina 27695, United States
| | - Kyle S. Bingham
- Department of Chemistry, NC State University, Raleigh, North Carolina 27695, United States
- Present address: UNC Chapel Hill School of Medicine, Chapel Hill, North Carolina 27516, United States
| | - Anuran K. Gayen
- Department of Chemistry, NC State University, Raleigh, North Carolina 27695, United States
| | - Gavin J. Williams
- Department of Chemistry, NC State University, Raleigh, North Carolina 27695, United States
- Comparative Medicine Institute, NC State University, Raleigh, North Carolina 27695, United States
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5
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Short Chain Fatty Acid Biosynthesis in Microalgae Synechococcus sp. PCC 7942. Mar Drugs 2019; 17:md17050255. [PMID: 31035409 PMCID: PMC6562792 DOI: 10.3390/md17050255] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 04/25/2019] [Indexed: 01/05/2023] Open
Abstract
Short chain fatty acids (SCFAs) are valued as a functional material in cosmetics. Cyanobacteria can accumulate SCFAs under some conditions, the related mechanism is unclear. Two potential genes Synpcc7942_0537 (fabB/F) and Synpcc7942_1455 (fabH) in Synechococcus sp. PCC 7942 have homology with fabB/F and fabH encoding β-ketoacyl ACP synthases (I/II/III) in plants. Therefore, effects of culture time and cerulenin on SCFAs accumulation, expression levels and functions of these two potential genes were studied. The results showed Synechococcus sp. PCC 7942 accumulated high SCFAs (C12 + C14) in early growth stage (day 4) and at 7.5g/L cerulenin concentration, reaching to 2.44% and 2.84% of the total fatty acids respectively, where fabB/F expression was down-regulated. Fatty acid composition analysis showed C14 increased by 65.19% and 130% respectively, when fabB/F and fabH were antisense expressed. C14 increased by 10.79% (fab(B/F)-) and 6.47% (fabH-) under mutation conditions, while C8 increased by six times in fab(B/F)- mutant strain. These results suggested fabB/F is involved in fatty acid elongation (C <18) and the elongation of cis-16:1 to cis-18:1 fatty acid in Synechococcus sp. PCC 7942, while fabH was involved in elongation of fatty acid synthesis, which were further confirmed in complementary experiments of E. coli. The research could provide the scientific basis for the breeding of SCFA-rich microalgae species.
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6
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Rath CM, Benton BM, de Vicente J, Drumm JE, Geng M, Li C, Moreau RJ, Shen X, Skepper CK, Steffek M, Takeoka K, Wang L, Wei JR, Xu W, Zhang Q, Feng BY. Optimization of CoaD Inhibitors against Gram-Negative Organisms through Targeted Metabolomics. ACS Infect Dis 2018; 4:391-402. [PMID: 29243909 DOI: 10.1021/acsinfecdis.7b00214] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Drug-resistant Gram-negative bacteria are of increasing concern worldwide. Novel antibiotics are needed, but their development is complicated by the requirement to simultaneously optimize molecules for target affinity and cellular potency, which can result in divergent structure-activity relationships (SARs). These challenges were exemplified during our attempts to optimize inhibitors of the bacterial enzyme CoaD originally identified through a biochemical screen. To facilitate lead optimization, we developed mass spectroscopy assays based on the hypothesis that levels of CoA metabolites would reflect the cellular enzymatic activity of CoaD. Using these methods, we were able to monitor the effects of cellular enzyme inhibition at compound concentrations up to 100-fold below the minimum inhibitory concentration (MIC), a common metric of growth inhibition. Furthermore, we generated a panel of efflux pump mutants to dissect the susceptibility of a representative CoaD inhibitor to efflux. These approaches allowed for a nuanced understanding of the permeability and efflux liabilities of the series and helped guide optimization efforts to achieve measurable MICs against wild-type E. coli.
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Affiliation(s)
- Christopher M. Rath
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Bret M. Benton
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Javier de Vicente
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Joseph E. Drumm
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Mei Geng
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Cindy Li
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Robert J. Moreau
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Xiaoyu Shen
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Colin K. Skepper
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Micah Steffek
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Kenneth Takeoka
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Lisha Wang
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Jun-Rong Wei
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Wenjian Xu
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Qiong Zhang
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Brian Y. Feng
- Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
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7
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Cha JY, Lee HJ. Targeting Lipid Metabolic Reprogramming as Anticancer Therapeutics. J Cancer Prev 2016; 21:209-215. [PMID: 28053954 PMCID: PMC5207604 DOI: 10.15430/jcp.2016.21.4.209] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 11/25/2016] [Accepted: 11/26/2016] [Indexed: 01/08/2023] Open
Abstract
Cancer cells rewire their metabolism to satisfy the demands of growth and survival, and this metabolic reprogramming has been recognized as an emerging hallmark of cancer. Lipid metabolism is pivotal in cellular process that converts nutrients into energy, building blocks for membrane biogenesis and the generation of signaling molecules. Accumulating evidence suggests that cancer cells show alterations in different aspects of lipid metabolism. The changes in lipid metabolism of cancer cells can affect numerous cellular processes, including cell growth, proliferation, differentiation, and survival. The potential dependence of cancer cells on the deregulated lipid metabolism suggests that enzymes and regulating factors involved in this process are promising targets for cancer treatment. In this review, we focus on the features associated with the lipid metabolic pathways in cancer, and highlight recent advances on the therapeutic targets of specific lipid metabolic enzymes or regulating factors and target-directed small molecules that can be potentially used as anticancer drugs.
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Affiliation(s)
- Ji-Young Cha
- Department of Biochemistry, Gachon University College of Medicine, Incheon, Korea
| | - Ho-Jae Lee
- Department of Biochemistry, Gachon University College of Medicine, Incheon, Korea
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8
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Disruption of lipid homeostasis in the Gram-negative cell envelope activates a novel cell death pathway. Proc Natl Acad Sci U S A 2016; 113:E1565-74. [PMID: 26929379 DOI: 10.1073/pnas.1601375113] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Gram-negative bacteria balance synthesis of the outer membrane (OM), cell wall, and cytoplasmic contents during growth via unknown mechanisms. Here, we show that a dominant mutation (designated mlaA*, maintenance of lipid asymmetry) that alters MlaA, a lipoprotein that removes phospholipids from the outer leaflet of the OM of Escherichia coli, increases OM permeability, lipopolysaccharide levels, drug sensitivity, and cell death in stationary phase. Surprisingly, single-cell imaging revealed that death occurs after protracted loss of OM material through vesiculation and blebbing at cell-division sites and compensatory shrinkage of the inner membrane, eventually resulting in rupture and slow leakage of cytoplasmic contents. The death of mlaA* cells was linked to fatty acid depletion and was not affected by membrane depolarization, suggesting that lipids flow from the inner membrane to the OM in an energy-independent manner. Suppressor analysis suggested that the dominant mlaA* mutation activates phospholipase A, resulting in increased levels of lipopolysaccharide and OM vesiculation that ultimately undermine the integrity of the cell envelope by depleting the inner membrane of phospholipids. This novel cell-death pathway suggests that balanced synthesis across both membranes is key to the mechanical integrity of the Gram-negative cell envelope.
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9
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Panova N, Zborníková E, Šimák O, Pohl R, Kolář M, Bogdanová K, Večeřová R, Seydlová G, Fišer R, Hadravová R, Šanderová H, Vítovská D, Šiková M, Látal T, Lovecká P, Barvík I, Krásný L, Rejman D. Insights into the Mechanism of Action of Bactericidal Lipophosphonoxins. PLoS One 2015; 10:e0145918. [PMID: 26716439 PMCID: PMC4696656 DOI: 10.1371/journal.pone.0145918] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 12/03/2015] [Indexed: 11/19/2022] Open
Abstract
The advantages offered by established antibiotics in the treatment of infectious diseases are endangered due to the increase in the number of antibiotic-resistant bacterial strains. This leads to a need for new antibacterial compounds. Recently, we discovered a series of compounds termed lipophosphonoxins (LPPOs) that exhibit selective cytotoxicity towards Gram-positive bacteria that include pathogens and resistant strains. For further development of these compounds, it was necessary to identify the mechanism of their action and characterize their interaction with eukaryotic cells/organisms in more detail. Here, we show that at their bactericidal concentrations LPPOs localize to the plasmatic membrane in bacteria but not in eukaryotes. In an in vitro system we demonstrate that LPPOs create pores in the membrane. This provides an explanation of their action in vivo where they cause serious damage of the cellular membrane, efflux of the cytosol, and cell disintegration. Further, we show that (i) LPPOs are not genotoxic as determined by the Ames test, (ii) do not cross a monolayer of Caco-2 cells, suggesting they are unable of transepithelial transport, (iii) are well tolerated by living mice when administered orally but not peritoneally, and (iv) are stable at low pH, indicating they could survive the acidic environment in the stomach. Finally, using one of the most potent LPPOs, we attempted and failed to select resistant strains against this compound while we were able to readily select resistant strains against a known antibiotic, rifampicin. In summary, LPPOs represent a new class of compounds with a potential for development as antibacterial agents for topical applications and perhaps also for treatment of gastrointestinal infections.
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Affiliation(s)
- Natalya Panova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
- Institute of Microbiology, Czech Academy of Sciences v.v.i., Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Eva Zborníková
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Ondřej Šimák
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Radek Pohl
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Milan Kolář
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 3, 775 15 Olomouc, Czech Republic
| | - Kateřina Bogdanová
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 3, 775 15 Olomouc, Czech Republic
| | - Renata Večeřová
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 3, 775 15 Olomouc, Czech Republic
| | - Gabriela Seydlová
- Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 43 Prague 2, Czech Republic
| | - Radovan Fišer
- Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, 128 43 Prague 2, Czech Republic
| | - Romana Hadravová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Hana Šanderová
- Institute of Microbiology, Czech Academy of Sciences v.v.i., Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Dragana Vítovská
- Institute of Microbiology, Czech Academy of Sciences v.v.i., Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Michaela Šiková
- Institute of Microbiology, Czech Academy of Sciences v.v.i., Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Tomáš Látal
- TRIOS, Ltd., Zakouřilova 142, Prague 4, 149 00, Prague, Czech Republic
| | - Petra Lovecká
- University of Chemistry and Technology, Technická 5, 166 28 Prague, Czech Republic
| | - Ivan Barvík
- Division of Biomolecular Physics, Institute of Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2, Czech Republic
| | - Libor Krásný
- Institute of Microbiology, Czech Academy of Sciences v.v.i., Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Dominik Rejman
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences v.v.i., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
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10
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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: 292] [Impact Index Per Article: 26.5] [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.
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Affiliation(s)
- Joshua B Parsons
- Department of Infectious Diseases, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
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11
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Yitzhaki S, Rostron JE, Xu Y, Rideout MC, Authement RN, Barlow SB, Segall AM. Similarities between exogenously- and endogenously-induced envelope stress: the effects of a new antibacterial molecule, TPI1609-10. PLoS One 2012; 7:e44896. [PMID: 23071502 PMCID: PMC3469575 DOI: 10.1371/journal.pone.0044896] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 08/15/2012] [Indexed: 11/19/2022] Open
Abstract
Antibiotics with novel and/or multiple targets are highly desirable in the face of the steady rise of clinical antibiotic resistance. We have screened and identified small molecules, typified by the compound TPI1609-10 (aka SM10), with antibiotic activity against both gram-positive and gram-negative bacteria. SM10 was screened in vitro to bind branched Holliday junction intermediates of homologous recombination and tyrosine recombinase-mediated recombination; thus, the cellular targets of the small molecules were expected to include the RuvABC Holliday junction resolvasome and the XerCD complex involved in proper segregation of replicated chromosomes to daughter cells. SM10 indeed induces DNA damage and filamentation in E. coli. However, SM10 also induces envelope stress and causes increased production of intracellular reactive oxygen species. In addition, SM10 has similar effects to endogenously-induced envelope stress via overproducing outer membrane proteins (OmpC and OmpF), which also induces the SOS response, chromosome fragmentation, and production of reactive oxygen species. The synergy between SM10, and cerulenin, a fatty acid synthesis inhibitor, together with the SM10 hypersensitivity of cpx and rpoE mutants, further support that SM10's mode of action damages membrane damage. The lethality of SM10 treatment and of OmpC overproduction are observed in both aerobically- and anaerobically-grown cells, and is accompanied by substantial DNA damage even anaerobically. Thus, only some DNA damage is due to reactive oxygen. We propose that membrane depolarization and the potential reduction in intracellular pH, leading to abasic site formation, cause a substantial amount of the DNA damage associated with both SM10 treatment and endogenous envelope stress. While it is difficult to completely exclude effects related to envelope damage as the sources of DNA damage, trapping intermediates associated with DNA repair and chromosome segregation pathways remains very likely. Thus SM10 may have distinct but synergistic modes of action.
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Affiliation(s)
- Shmuel Yitzhaki
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, United States of America
| | - Jason E. Rostron
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, United States of America
| | - Yan Xu
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, United States of America
| | - Marc C. Rideout
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, United States of America
| | - R. Nathan Authement
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, United States of America
| | - Steven B. Barlow
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, United States of America
- Electron Microscopy Facility, San Diego State University, San Diego, California, United States of America
| | - Anca M. Segall
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, United States of America
- * E-mail:
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Surfactants, aromatic and isoprenoid compounds, and fatty acid biosynthesis inhibitors suppress Staphylococcus aureus production of toxic shock syndrome toxin 1. Antimicrob Agents Chemother 2009; 53:1898-906. [PMID: 19223628 DOI: 10.1128/aac.01293-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Menstrual toxic shock syndrome is a rare but potentially life-threatening illness manifest through the actions of Staphylococcus aureus toxic shock syndrome toxin 1 (TSST-1). Previous studies have shown that tampon additives can influence staphylococcal TSST-1 production. We report here on the TSST-1-suppressing activity of 34 compounds that are commonly used additives in the pharmaceutical, food, and perfume industries. Many of the tested chemicals had a minimal impact on the growth of S. aureus and yet were potent inhibitors of TSST-1 production. The TSST-1-reducing compounds included surfactants with an ether, amide, or amine linkage to their fatty acid moiety (e.g., myreth-3-myristate, Laureth-3, disodium lauroamphodiacetate, disodium lauramido monoethanolamido, sodium lauriminodipropionic acid, and triethanolamine laureth sulfate); aromatic compounds (e.g. phenylethyl and benzyl alcohols); and several isoprenoids and related compounds (e.g., terpineol and menthol). The membrane-targeting and -altering effects of the TSST-1-suppressing compounds led us to assess the activity of molecules that are known to inhibit fatty acid biosynthesis (e.g., cerulenin, triclosan, and hexachlorophene). These compounds also reduced S. aureus TSST-1 production. This study suggests that more additives than previously recognized inhibit the production of TSST-1.
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Haynes CA, Allegood JC, Sims K, Wang EW, Sullards MC, Merrill AH. Quantitation of fatty acyl-coenzyme As in mammalian cells by liquid chromatography-electrospray ionization tandem mass spectrometry. J Lipid Res 2008; 49:1113-25. [PMID: 18287618 DOI: 10.1194/jlr.d800001-jlr200] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fatty acyl-CoAs participate in numerous cellular processes. This article describes a method for the quantitation of subpicomole amounts of long-chain and very-long-chain fatty acyl-CoAs by reverse-phase LC combined with electrospray ionization tandem mass spectrometry in positive ion mode with odd-chain-length fatty acyl-CoAs as internal standards. This method is applicable to a wide range of species [at least myristoyl- (C14:0-) to cerotoyl- (C26:0-) CoA] in modest numbers of cells in culture ( approximately 10(6)-10(7)), with analyses of RAW264.7 cells and MCF7 cells given as examples. Analysis of these cells revealed large differences in fatty acyl-CoA amounts (12 +/- 1.0 pmol/10(6) RAW264.7 cells vs. 80.4 +/- 6.1 pmol/10(6) MCF7 cells) and subspecies distribution. Very-long-chain fatty acyl-CoAs with alkyl chain lengths > C20 constitute <10% of the total fatty acyl-CoAs of RAW264.7 cells versus >50% for MCF7 cells, which somewhat astonishingly contain approximately as much C24:0- and C26:0-CoAs as C16:0- and C18:0-CoAs and essentially equal amounts of C26:1- and C18:1-CoAs. This simple and robust method should facilitate the inclusion of this family of compounds in "lipidomics" and "metabolomics" studies.
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Abstract
Detoxification is essential for the fungal growth in the drug stress environments, and the multidrug transporters play an important role in this process. Here a cerulenin transporter gene (MpMdt, AB206476) was identified from Monascus pilosus. MpMdt mRNA contains 1951 bp and encodes a protein of 559 amino acid residues with 11 trans-membrane domains; and there is no difference in the sequence of MpMdt mRNA between the wild type M. pilosus IFO4520 and its cerulenin resistant mutant MK-1. Up-expression of MpMdt renders the cerulenin resistance of the mutant MK-1. Over-expression of MpMdt could also increase the cerulenin tolerance in the transgenic M. pilosus IFO4520. These results suggested that MpMdt is able to efflux-transport the anti-fungal antibiotic cerulenin and increase the cerulenin resistance of M. pilosus.
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Affiliation(s)
- Mingyong Zhang
- South China Botanical Garden, Chinese Academy of Sciences. Guangzhou, P. R. China.
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15
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García D, Mañas P, Gómez N, Raso J, Pagán R. Biosynthetic requirements for the repair of sublethal membrane damage in Escherichia coli cells after pulsed electric fields. J Appl Microbiol 2006; 100:428-35. [PMID: 16478482 DOI: 10.1111/j.1365-2672.2005.02795.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The aim was to evaluate the biosynthetic requirements for the repair of sublethal membrane damages in Escherichia coli cells after exposure to pulsed electric fields (PEF). METHODS AND RESULTS The partial loss of the barrier and homeostatic functions of the cytoplasmic membrane was examined by adding sodium chloride to the recovery media. More than 4 log10 cycles of survivors were sublethally injured after PEF. Repair of such sublethal membrane damages occurred when survivors to PEF were incubated in peptone water for 2 h. Two different types of sublethally injured cells were detected. Whereas a small proportion (<5%) repaired after PEF in less than 2 min, the repair of the remaining 95% injured cells lasted 2 h and was dependent on biosynthetic requirements. The addition of inhibitors such as chloramphenicol, cerulenin, penicillin G, rifampicin and sodium azide to the liquid repair medium showed that the repair required energy and lipid synthesis, and was not dependent on protein, peptidoglican or RNA synthesis. CONCLUSIONS Cell survival after PEF is dependent on the repair of the cytoplasmic membrane. Requirement of lipid synthesis for the repair of sublethally injured cells confirms that the cytoplasmic membrane is a target directly involved in the mechanism of inactivation by PEF. SIGNIFICANCE AND IMPACT OF THE STUDY Knowledge about the damages inflicted by PEF might help in the design of more efficient treatments.
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Affiliation(s)
- D García
- Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain
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16
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Adhikari RP, Novick RP. Subinhibitory cerulenin inhibits staphylococcal exoprotein production by blocking transcription rather than by blocking secretion. MICROBIOLOGY-SGM 2005; 151:3059-3069. [PMID: 16151216 DOI: 10.1099/mic.0.28102-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cerulenin is an antibiotic that inhibits fatty acid synthesis by covalent modification of the active thiol of the chain-elongation subtypes of beta-ketoacyl-acyl carrier protein synthase. It also inhibits other processes that utilize essential thiols. Cerulenin has been widely reported to block protein secretion at sub-MIC levels, an effect that has been postulated to represent interference with membrane function through interference with normal fatty acid synthesis. This study confirms the profound reduction in extracellular proteins caused by low concentrations of the antibiotic, and shows by Northern blot hybridization that this reduction is due to interference with transcription. By exchanging promoters between entB, a gene that is inhibited by cerulenin, and entA, a gene that is not, it was also shown that the antibiotic does not block secretion. Subinhibitory concentrations of cerulenin were also found to block transcriptional activation of at least two regulatory determinants, agr and sae, that function by signal transduction. Interference with the activation of these and other regulatory determinants probably accounts for much of the inhibitory effect on exoprotein production of sub-MIC concentrations of cerulenin.
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Affiliation(s)
- Rajan P Adhikari
- Molecular Pathogenesis Program, Skirball Institute of Biomolecular Medicine and Department of Microbiology, New York University Medical Center, 540 First Avenue, New York, NY 10016, USA
| | - Richard P Novick
- Molecular Pathogenesis Program, Skirball Institute of Biomolecular Medicine and Department of Microbiology, New York University Medical Center, 540 First Avenue, New York, NY 10016, USA
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17
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Affiliation(s)
- Charles O Rock
- The Protein Science Division, Department of Infectious Diseases, St. Jude Children's Research Hospital, 332 N. Lauderdale Street, Memphis, TN 38105, USA.
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18
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Nieboer M, Gunnewijk M, van Beilen JB, Witholt B. Determinants for overproduction of the Pseudomonas oleovorans cytoplasmic membrane protein alkane hydroxylase in alk+ Escherichia coli W3110. J Bacteriol 1997; 179:762-8. [PMID: 9006031 PMCID: PMC178758 DOI: 10.1128/jb.179.3.762-768.1997] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The Pseudomonas oleovorans alkB gene is expressed in alk+ Escherichia coli W3110 to 10 to 15% of the total cell protein, which is exceptional for a (foreign) cytoplasmic membrane protein. In other E. coli recombinants such as alk+ HB101, AlkB constitutes 2 to 3% of the total protein. In this study, we have investigated which factors determine the expression level of alkB in alk+ W3110. In particular, we have investigated the role of AlkB-induced stimulation of phospholipid synthesis. Blocking phospholipid synthesis in alk+ W3110 did not specifically alter the expression of alkB, and we conclude that stimulation of phospholipid synthesis is not a prerequisite for high-level expression of the membrane protein. W3110 is able to produce exceptionally high levels of alkane monooxygenase, because the rate of alkB mRNA synthesis in W3110 is an order of magnitude higher than that in HB101. This may be due in part to the higher copy number of pGEc47 in W3110 in comparison with HB101.
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Affiliation(s)
- M Nieboer
- Institut of Biotechnology, ETH Hönggerberg (HPT), Zürich, Switzerland
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19
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Nieboer M, Vis AJ, Witholt B. Overproduction of a foreign membrane protein in Escherichia coli stimulates and depends on phospholipid synthesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 241:691-6. [PMID: 8917473 DOI: 10.1111/j.1432-1033.1996.00691.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
When the Pseudomonas oleovorans alk system, consisting of the alkBFGHJKL and alkST genes, is expressed in Escherichia coli W3110, significant changes in phospholipid metabolism of the host are observed. A major role seems to be played by the cytoplasmic membrane protein alkane hydroxylase (AlkB), which is synthesized as up to 10-15% of the total protein in this strain [Nieboer, M., Kingma, J. & Witholt, B. (1993) The alkane oxidation system of Pseudomonas oleovorans: induction of the alk genes in Escherichia coli W3110[pGEc47] affects membrane biogenesis and results in overexpression of alkane hydroxylase in a distinct cytoplasmic membrane subfraction, Mol. Microbiol. 8, 1039-1051]. In the present paper, we have studied the link between synthesis of the membrane protein and the synthesis of phospholipids and fatty acids by examining the kinetics of these processes. Using [35S]methionine labeling, it was shown that induction of AlkB was maximal within 30-60 min after addition of inducer, when up to 15% of all newly synthesized protein is AlkB. Phospholipid synthesis was followed by measuring the incorporation of 14C-labeled acetate and 33P-labeled phosphoric acid into phospholipids. Despite a negative effect of the inducer on the growth rate of W3110[pGEc47], net phospholipid synthesis was significantly enhanced as a result of the expression of alkB. Synthesis of all three major phospholipids were stimulated to comparable extents by the induction of alkB. Induction did not increase 33P incorporation into lipids in the control recombinant alk+ strain which lacked alkB. Simultaneous with AlkB synthesis, the conversion of unsaturated 9-hexadecenoic acid (C16:1) into 9,10-methylene hexadecanoic acid (C17:ocyc) was reduced in the alk+ recombinant. Overall, these data show that the production of a foreign membrane protein in E. coli can engender a response of the phospholipid-synthesizing system of the host. In the absence of such a response, induction of the alk system would be much more toxic to the cells. Apparently, the increased phospholipid synthesis plays an important role in enabling the AlkB overproducing strain to grow.
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Affiliation(s)
- M Nieboer
- Institute of Biotechnology, ETH Hönggerberg (HPT), Zürich, Switzerland
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20
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Rodionov DG, Pisabarro AG, de Pedro MA, Kusser W, Ishiguro EE. Beta-lactam-induced bacteriolysis of amino acid-deprived Escherichia coli is dependent on phospholipid synthesis. J Bacteriol 1995; 177:992-7. [PMID: 7860611 PMCID: PMC176694 DOI: 10.1128/jb.177.4.992-997.1995] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The penicillin tolerance of amino acid-deprived relA+ Escherichia coli is attributed to the stringent response; i.e., relaxation of the stringent response suppresses penicillin tolerance. The beta-lactam-induced lysis of amino acid-deprived bacteria resulting from relaxation of the stringent response was inhibited by cerulenin, or by glycerol deprivation in the case of a gpsA mutant (defective in the biosynthetic sn-glycerol 3-phosphate dehydrogenase). Therefore, beta-lactam-induced lysis of amino acid-deprived cells was dependent on phospholipid synthesis. The lysis process during amino acid deprivation can be experimentally dissociated into two stages designated the priming stage (during which the interaction between the beta-lactam and the penicillin-binding proteins occurs) and the beta-lactam-independent lysis induction stage. Both stages were shown to require phospholipid synthesis. It has been known for some time that the inhibition of phospholipid synthesis is among the plethora of physiological changes resulting from the stringent response. These results indicate that the inhibition of peptidoglycan synthesis and the penicillin tolerance associated with the stringent response are both secondary consequences of the inhibition of phospholipid synthesis.
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Affiliation(s)
- D G Rodionov
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
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21
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Henning U, Koebnik R. Chapter 18 Outer membrane proteins of Escherichia coli: mechanism of sorting and regulation of synthesis. BACTERIAL CELL WALL 1994. [DOI: 10.1016/s0167-7306(08)60421-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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22
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Morisaki N, Funabashi H, Shimazawa R, Furukawa J, Kawaguchi A, Okuda S, Iwasaki S. Effect of side-chain structure on inhibition of yeast fatty-acid synthase by cerulenin analogues. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 211:111-5. [PMID: 8425521 DOI: 10.1111/j.1432-1033.1993.tb19876.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Yeast fatty-acid synthase (FAS) inhibition by cerulenin analogs with varying side-chain lengths was compared with that of cerulenin, tetrahydrocerulenin and iodoacetamide. Although inhibition by cerulenin was the highest, the analogs having (E,E)-delta 7,10 double bonds showed high inhibition. This strongly suggests that the (E,E)-delta 7,10 double bonds play an important role in the interaction of the inhibitors with the enzyme. It was suggested that the size of the hydrophobic cavity in the condensing enzyme terminates fatty-acid chain elongation by decreasing inhibition by the C18 analog. Like cerulenin itself, the shortest analog (C6) did not induce malonyl-CoA decarboxylase activity.
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Affiliation(s)
- N Morisaki
- Institute of Applied Microbiology, University of Tokyo, Japan
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Fourel D, Mizushima S, Pagès JM. Dynamics of the exposure of epitopes on OmpF, an outer membrane protein of Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 206:109-14. [PMID: 1375155 DOI: 10.1111/j.1432-1033.1992.tb16907.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The OmpF protein is the major outer membrane trimeric porin of Escherichia coli B. The exposure of several cell-surface-exposed epitopes, that are recognized by various monoclonal antibodies directed against the protein, is investigated. Kinetic analyses show that two epitopes (E18 and E19) appear early during the in-vivo assembly on the folded monomer, just after the removal of the signal peptide, and are conserved in the native trimer. The trimerization that immediately follows or occurs in conjunction with the folding of monomers exposes another antigenic site (E21) at the surface of metastable forms. The binding of nascent lipopolysaccharide promotes the conversion of the heat-modifiable intermediate to a stable trimer and ensures the exposure of E20, E1, E3, E4 and E7. Late epitopes, E1, E3, E4 and E7 are only detected in the outer membrane fraction. These results suggest that different steps induce the sequential exposure of native antigenic sites. The detection of these epitopes depends on conformational changes occurring during the OmpF insertion into the outer membrane.
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Affiliation(s)
- D Fourel
- Centre de Biochimie et de Biologie Moléculaire, Centre National de la Recherche Scientifique, Marseille, France
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Ried G, Hindennach I, Henning U. Role of lipopolysaccharide in assembly of Escherichia coli outer membrane proteins OmpA, OmpC, and OmpF. J Bacteriol 1990; 172:6048-53. [PMID: 2170338 PMCID: PMC526928 DOI: 10.1128/jb.172.10.6048-6053.1990] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Selection was performed for resistance to a phage, Ox2, specific for the Escherichia coli outer membrane protein OmpA, under conditions which excluded recovery of ompA mutants. All mutants analyzed produced normal quantities of OmpA, which was also normally assembled in the outer membrane. They had become essentially resistant to OmpC and OmpF-specific phages and synthesized these outer membrane porins at much reduced rates. The inhibition of synthesis acted at the level of translation. This was due to the presence of lipopolysaccharides (LPS) with defective core oligosaccharides. Cerulenin blocks fatty acid synthesis and therefore that of LPS. It also inhibits synthesis of OmpC and OmpF but not of OmpA (C. Bocquet-Pagès, C. Lazdunski, and A. Lazdunski, Eur. J. Biochem. 118:105-111, 1981). In the presence of the antibiotic, OmpA synthesis and membrane incorporation remained unaffected at a time when OmpC and OmpF synthesis had almost ceased. The similarity of these results with those obtained with the mutants suggests that normal porin synthesis is not only interfered with by production of mutant LPS but also requires de novo synthesis of LPS. Since synthesis and assembly of OmpA into the outer membrane was not affected in the mutants or in the presence of cerulenin, association of this protein with LPS appears to occur with outer membrane-located LPS.
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Affiliation(s)
- G Ried
- Max-Planck-Institut für Biologie, Tübingen, Federal Republic of Germany
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25
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Quinn PJ, Joo F, Vigh L. The role of unsaturated lipids in membrane structure and stability. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1989; 53:71-103. [PMID: 2692073 DOI: 10.1016/0079-6107(89)90015-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Wortman AT, Bissonnette GK. Metabolic processes involved in repair of Escherichia coli cells damaged by exposure to acid mine water. Appl Environ Microbiol 1988; 54:1901-6. [PMID: 2460026 PMCID: PMC202776 DOI: 10.1128/aem.54.8.1901-1906.1988] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Escherichia coli was stressed by exposure to filter-sterilized acid mine water. Synthetic processes required for repair of sublethally injured survivors were studied by the addition of specific metabolic inhibitors to a resuscitation broth. Inhibitors of protein, RNA, DNA, lipid, and peptidoglycan synthesis as well as uncouplers and inhibitors of electron transport and ATPase activity were used. Acid mine water injury was severe, causing damage to the outer and cytoplasmic membranes. Repair of sublethally injured cells required protein, RNA, and lipid synthesis as well as a proton motive force.
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Affiliation(s)
- A T Wortman
- Division of Plant and Soil Sciences, West Virginia University, Morgantown 26506-6057
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28
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Sanadi S, Pandey R, Khuller GK. Reversal of cerulenin-induced inhibition of phospholipids and sterol synthesis by exogenous fatty acids/sterols in Epidermophyton floccosum. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 921:341-6. [PMID: 3651491 DOI: 10.1016/0005-2760(87)90035-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cerulenin, a specific inhibitor of fatty acids and sterol biosynthesis inhibited the growth of Epidermophyton floccosum, which was reversed when growth medium was supplemented with palmitic acid and sterols. Unsaturated fatty acids partially restored the growth. Cerulenin inhibited both phospholipid and sterol biosynthesis (60-70%) at the minimum inhibitory concentration (0.5 microgram/ml) as demonstrated by [32P]orthophosphoric acid and [14C]acetate incorporation into the respective lipids. Cerulenin-induced inhibition of phospholipid and sterol synthesis was dose dependent up to 0.5 microgram/ml. Exogenously supplied fatty acids and sterols restored the biosynthesis of phospholipids in cerulenin-treated cultures, while that of sterols was enhanced. The biosynthesis of both saturated and unsaturated fatty acids was inhibited by cerulenin.
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Affiliation(s)
- S Sanadi
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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29
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O'Neill EA, Bender RA. Periodic synthesis of phospholipids during the Caulobacter crescentus cell cycle. J Bacteriol 1987; 169:2618-23. [PMID: 3584065 PMCID: PMC212137 DOI: 10.1128/jb.169.6.2618-2623.1987] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Net phospholipid synthesis is discontinuous during the Caulobacter crescentus cell cycle with synthesis restricted to two discrete periods. The first period of net phospholipid synthesis begins in the swarmer cell shortly after cell division and ends at about the time when DNA replication initiates. The second period of phospholipid synthesis begins at a time when DNA replication is about two-thirds complete and ends at about the same time that DNA replication terminates. Thus, considerable DNA replication, growth, and differentiation (stalk growth) occur in the absence of net phospholipid synthesis. In fact, when net phospholipid synthesis was inhibited by the antibiotic cerulenin through the entire cell cycle, both the initiation and the elongation phases of DNA synthesis occurred normally. An analysis of the kinetics of incorporation of radioactive phosphate into macromolecules showed that the periodicity of phospholipid synthesis could not have been detected by pulse-labeling techniques, and only an analysis of cells prelabeled to equilibrium allowed detection of the periodicity. Equilibrium-labeled cells also allowed determination of the absolute amount of phosphorus-containing macromolecules in newborn swarmer cells. These cells contain about as much DNA as one Escherichia coli chromosome and about four times as much RNA as DNA. The amount of phosphorus in phospholipids is about one-seventh of that in DNA, or about 3% of the total macromolecular phosphorus.
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Mahajan S, Khuller GK. Cerulenin effect on phospholipid metabolism in Mycobacterium smegmatis ATCC 607. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 795:493-8. [PMID: 6477957 DOI: 10.1016/0005-2760(84)90178-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Phospholipid metabolism in the presence of a subinhibitory concentration of cerulenin was studied in Mycobacterium smegmatis ATCC 607 by pulse labelling and subsequent chasing of radioactivity in phospholipids using [32P]orthophosphate. Cerulenin inhibited biosynthesis of total phospholipids to a significant level which is reflected equally in all the phospholipid components (phosphatidylethanolamine, phosphatidylinositol mannosides and cardiolipin) within the time of exposure. On chase, alteration in degradation of all phospholipid components was observed on cerulenin treatment, in comparison with control cells. Differences seen in the metabolism of phospholipids in cerulenin-treated and control cells are discussed.
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Shepherd WD, Kaplan S. Effect of cerulenin on macromolecule synthesis in chemoheterotrophically and photoheterotrophically grown Rhodopseudomonas sphaeroides. J Bacteriol 1983; 156:1322-31. [PMID: 6196350 PMCID: PMC217983 DOI: 10.1128/jb.156.3.1322-1331.1983] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The antibiotic cerulenin causes the immediate cessation of phospholipid biosynthesis in both chemoheterotrophic and photoheterotrophic cultures of Rhodopseudomonas sphaeroides. Macromolecule biosynthesis in photoheterotrophic cells was unaffected by cerulenin for the first 2 h after antibiotic addition and then continued at a reduced rate for an additional 8 h. In contrast, macromolecule biosynthesis in chemoheterotrophic cells was severely affected by cerulenin within the first 2 h of treatment. Pulse-labeling of protein after cerulenin addition revealed that all subcellular fractions were equally affected by the action of cerulenin with chemoheterotrophic cell fractions more profoundly affected than those derived from photoheterotrophic cells. Protein insertion into the intracytoplasmic membrane of photoheterotrophic cells continued for up to 6 h after the onset of cerulenin treatment. Residual macromolecule synthesis was correlated with the presence of the photosynthetic membrane system under all conditions of growth.
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Uratani B, Lopez JM, Freese E. Effect of decoyinine on peptidoglycan synthesis and turnover in Bacillus subtilis. J Bacteriol 1983; 154:261-8. [PMID: 6403504 PMCID: PMC217455 DOI: 10.1128/jb.154.1.261-268.1983] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The sporulation of Bacillus subtilis can be induced in the presence of amino acids and glucose by partially depriving the cells of guanine nucleotides. This can be achieved, e.g., by the addition of decoyinine, a specific inhibitor of GMP synthetase. To determine the effect of this and other inhibitors on cell wall synthesis, we measured in their presence the incorporation of acetylglucosamine into acid-precipitable material. The rate of wall synthesis decreased by 50% within 5 min after decoyinine addition; this decrease was prevented by the presence of guanosine. A comparison with the effects of other inhibitors of cell wall synthesis indicated that decoyinine inhibited the final portion of the cell wall biosynthetic pathway, i.e., after the steps inhibited by bacitracin or vancomycin. Decoyinine addition also prevented cellular autolysis and cell wall turnover. It is not known whether these two effects of decoyinine on cell wall synthesis are causally related.
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Abstract
Exogenously supplied long-chain fatty acids have been shown to markedly alleviate the inhibition of phototrophic growth of cultures of Rhodopseudomonas sphaeroides caused by the antibiotic cerulenin. Monounsaturated and polyunsaturated C18 fatty acids were most effective in relieving growth inhibition mediated by cerulenin. Medium supplementation with saturated fatty acids (C14 to C18) failed to influence the inhibitory effect of cerulenin. The addition of mixtures of unsaturated and saturated fatty acids to the growth medium did not enhance the growth of cerulenin-inhibited cultures above that obtained with individual unsaturated fatty acids as supplements. Resolution and fatty acid analysis of the extractable lipids of R. sphaeroides revealed that exogenously supplied fatty acids were directly incorporated into cellular phospholipids. Cells treated with cerulenin displayed an enrichment in their percentage of total saturated fatty acids irrespective of the presence of exogenous fatty acids. Cerulenin produced comparable inhibitions of the rates of both fatty acid and phospholipid synthesis and was further found to preferentially inhibit unsaturated fatty acid synthesis.
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Dahl JS, Dahl CE. Coordinate regulation of unsaturated phospholipid, RNA, and protein synthesis in Mycoplasma capricolum by cholesterol. Proc Natl Acad Sci U S A 1983; 80:692-6. [PMID: 6187002 PMCID: PMC393445 DOI: 10.1073/pnas.80.3.692] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The effect of cholesterol, epicoprostanol, and phosphatidylcholine on phospholipid, RNA, and protein synthesis was investigated in the sterol auxotroph Mycoplasma capricolum. Cells growing poorly on lanosterol were stimulated to grow more rapidly by supplementing the medium with either 2 micrograms of cholesterol or 2.2 micrograms of egg phosphatidylcholine per ml. In such cells cholesterol caused a sequential stimulation of phospholipid, RNA, and protein synthesis. Enhanced oleate incorporation into phospholipid occurred early; the rates of RNA and protein synthesis increased later. In cells supplemented with phosphatidylcholine only RNA and protein syntheses were enhanced. The addition of 2 micrograms of epicoprostanol per ml to cells growing on lanosterol promptly inhibited the rate of unsaturated phospholipid synthesis and subsequently the rate of growth. Inhibition of both processes was relieved by supplying 2 micrograms of cholesterol or 2.2 micrograms of phosphatidylcholine per ml along with the inhibitory sterol. The results suggest that cholesterol in small amounts exerts a positive regulatory effect and epicoprostanol exerts a negative one on unsaturated phospholipid synthesis and, in turn, that RNA and protein synthesis are coordinately controlled with phospholipid synthesis. The previously reported phenomenon of sterol synergism and the postulated novel role of sterols in membranes.
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Rossomando EF, Jahngen EG. Permeability of Dictyostelium discoideum to fucose and uracil following growth-arrest induced by starvation, hadacidin, and cerulenin. Differentiation 1982; 23:13-6. [PMID: 7152166 DOI: 10.1111/j.1432-0436.1982.tb01261.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The uptake of fucose and uracil by Dictyostelium discoideum in either a starvation or drug-induced growth-arrest state was studied. For both nutrients, the uptake was an energy-dependent process. The rate of fucose uptake remained constant for over four hours, while the uracil rate declined after about one hour, in starvation-induced growth-arrest. Under these conditions, fucose was found to be incorporated into membrane-associated glycoproteins and glycolipids, while uracil was incorporated into RNA. The rate of fucose uptake was the same for starvation or hadacidin-induced growth-arrest, but significantly lower for cerulenin-treated cells. In contrast, uracil uptake was slower in hadacidin-treated cells as opposed to starvation or cerulenin-induced growth-arrest cells. Further experiments showed that the incorporation rate of uracil into RNA was faster in hadacidin-treated cells than controls, and the cerulenin-treated cells were slower. The data suggest that the cells arrested in growth by nutrient deprivation retain the capacity to take-up and incorporate nutrients such as fucose and uracil and that pinocytosis is probably the process responsible for uptake.
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Shapiro L, Mansour J, Shaw P, Henry S. Synthesis of specific membrane proteins is a function of DNA replication an phospholipid synthesis in Caulobacter crescentus. J Mol Biol 1982; 159:303-22. [PMID: 7143443 DOI: 10.1016/0022-2836(82)90497-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Murgier M, Pages C, Lazdunski C, Lazdunski A. Translational control ofOmpF, OmpCandLamBgenetic expression during lipid synthesis inhibition ofEscherichia coli. FEMS Microbiol Lett 1982. [DOI: 10.1111/j.1574-6968.1982.tb08278.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Pages C, Lazdunski C, Lazdunski A. The receptor of bacteriophage lambda: evidence for a biosynthesis dependent on lipid synthesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 122:381-6. [PMID: 6460624 DOI: 10.1111/j.1432-1033.1982.tb05892.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Inhibition of lipid synthesis in cerulenin-treated cells or in a mutant strain defective in sn-glycerol-3-phosphate acyltransferase after glycerol deprivation, results in a marked decrease of insertion of lamB protein into the outer membrane. No lambda receptor was found in any other cell compartment or in the medium under these conditions. The LamB protein synthesis was inhibited by about 70% in the absence of lipid synthesis. The residual 30% protein produced during inhibition of fatty-acid or phospholipid synthesis, was probably incorporated into the outer membrane since no further incorporation was observed after resumption of these syntheses. Besides OmpF and OmpC protein [Bocquet-Pagès, C., Lazdunski, C., and Lazdunski, A. (1981) Eur. J. Biochem. 118, 105-111], at least four other proteins of the outer membrane are also subject to alteration of levels in the absence of lipid synthesis. Under these conditions the uptake of maltose, like the uptake of 5'AMP [Bocquet-Pagès, C., Lazdunski, C., and Lazdunski, A. (1981) Eur. J. Biochem. 118, 105-111], was inhibited as much as 60%. These results are discussed with regard to the biosynthesis and assembly of the outer membrane proteins.
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Prior RL, Smith SB, Jacobson JJ. Metabolic pathways involved in lipogenesis from lactate and acetate in bovine adipose tissue: effects of metabolic inhibitors. Arch Biochem Biophys 1981; 211:202-10. [PMID: 7305365 DOI: 10.1016/0003-9861(81)90445-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Bocquet-Pages C, Lazdunski C, Lazdunski A. Lipid-synthesis-dependent biosynthesis (or assembly) of major outer-membrane proteins of Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 1981; 118:105-11. [PMID: 7026237 DOI: 10.1111/j.1432-1033.1981.tb05491.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Upon inhibition of fatty acid synthesis in the presence of cerulenin, the uptake of 5' AMP and of other nutrients using similar pore systems can be inhibited as much as 70%. The same effect was observed upon inhibition of phospholipid synthesis after glycerol deprivation in a mutant strain defective in sn-glycerol-3-phosphate acyltransferase. Resumption of both fatty acid synthesis and phospholipid synthesis restores a normal uptake of 5' AMP. The protein composition of the outer membranes, analyzed after pulse radiolabelling by [35S]methionine, was mainly altered in OmpF and OmpC proteins. These proteins are the main porins used by most nutrients like 5' AMP. Whereas the synthesis or the assembly of OmpF protein seems to be more inhibited that that of OmpC protein after inhibition of fatty acid synthesis, the reverse case was observed after inhibition of phospholipid synthesis. No protein produced during inhibition of fatty-acid or phospholipid synthesis is reincorporated into the outer membrane after resumption of these syntheses. These results are discussed with regard to the biosynthesis and assembly of these proteins.
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Bocquet C, Lazdunski A. Synthesis and export of colicin A and colicin E1 during inhibition of lipid synthesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1981; 115:75-77. [PMID: 6785088 DOI: 10.1111/j.1432-1033.1981.tb06199.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The antibiotic cerulenin, a specific inhibitor of fatty acid synthesis was used to demonstrate that colicin A and colicin E1 can be synthesized and exported during inhibition of lipid synthesis.
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Mansour JD, Henry S, Shapiro L. Phospholipid biosynthesis is required for stalk elongation in Caulobacter crescentus. J Bacteriol 1981; 145:1404-9. [PMID: 7204344 PMCID: PMC217145 DOI: 10.1128/jb.145.3.1404-1409.1981] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Membrane phospholipid synthesis was inhibited in Caulobacter crescentus by growth of a glycerol auxotroph in the absence of glycerol or by treatment with the antibiotic cerulenin. It was observed that the final step in the swarmer cell-to-stalked cell transition, stalk elongation, was inhibited under these conditions. Since an early effect of inhibiting phospholipid synthesis in C. crescentus is the termination of deoxyribonucleic acid (DNA) replication (I. Contreras, R. Bender, A. Weissborn, K. Amemiya J. D. Mansour, S. Henry, and L. Shapiro, J. Mol. Biol. 138:401-410, 1980), we questioned whether the inhibition of stalk formation was due directly to the inhibition phospholipid synthesis or secondarily to the inhibition of DNA synthesis. Under conditions which inhibited DNA synthesis but permitted phospholipid synthesis, i.e., growth of a temperature-sensitive DNA elongation mutant at the restrictive temperature or treatment with hydroxy-urea, stalk elongation occurred normally. Therefore phospholipid synthesis is required for stalk elongation in C. crescentus.
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Quinn PJ. The fluidity of cell membranes and its regulation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1981; 38:1-104. [PMID: 7025092 DOI: 10.1016/0079-6107(81)90011-0] [Citation(s) in RCA: 237] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Contreras I, Weissborn A, Amemiya K, Mansour J, Henry S, Shapiro L, Bender R. The effect of termination of membrane phospholipid synthesis on cell-dependent events in Caulobacter. J Mol Biol 1980; 138:401-9. [PMID: 6157828 DOI: 10.1016/0022-2836(80)90295-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Abstract
The membranes of living organisms are involved in many aspects of the life, growth and development of all cells. The predominant structural elements of these membranes are lipids and proteins and the basic strucvture of these molecules has been reviewed. The physical properties of the lipid constituents particularly their behavior in aqueous systems has led to the concepts of thermotropic and lyotropic mesomorphism; the interaction between different types of lipid molecules modulate this behavior. Interaction of phospholipids in aqueous systems with cholesterol, ions and drugs have been examined in this context. In addition a variety of model lipid-protein systems have been investigated and the implications of interactions between lipids and different proteins in biological membranes has been evaluated. This leads to a detailed consideration of the way lipids and proteins ae organized in cell membranes and contains an appraisal of the evidence supporting contemporary views of membrane structure. Particular attention has been devoted to the question of how mobile the components are within the structure. Particular attention has been devoted to the question of how mobile the components are within the structure. Finally the biosynthesis, turnover and modulation of the properties of interacting membrane constituents is critically reviewed and possible ways of controlling the behavior of cells and organisms by altering the structural parameters of different membranes has been considered.
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Contreras I, Bender RA, Mansour J, Henry S, Shapiro L. Caulobacter cresentus mutant defective in membrane phospholipid synthesis. J Bacteriol 1979; 140:612-9. [PMID: 500564 PMCID: PMC216689 DOI: 10.1128/jb.140.2.612-619.1979] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
To study the relationship between phospholipid synthesis and organelle biogenesis in the dimorphic bacterium Caulobacter crescentus, auxotrophs have been isolated which require exogenous glycerol or glycerol 3-phosphate for growth when glucose is used as the carbon source. Upon glycerol deprivation, net phospholipid synthesis ceased immediately in a glycerol 3-phosphate auxotroph which was shown to have levels of biosynthetic sn-glycerol 3-phosphate dehydrogenase (E.C. 1.1.1.8) activity 10 times lower than that of the wild type. In the absence of glycerol, the optical density of the culture continued to increase for the equivalent of one generation, although the cells did not divide. After the equivalent of one generation time, rapid cell death occurred. Cell death also occurred when phospholipid synthesis was inhibited by cerulenin. Although ribonucleic acid and protein syntheses continued at a reduced rate for the equivalent of one generation in mutant strains, a substantial decrease in the rate of deoxyribonucleic acid synthesis occurred immediately upon glycerol deprivation. Revertant strains had wild-type levels of glycerol 3-phosphate dehydrogenase activity and normal rates of phospholipid and macromolecular synthesis.
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Kawaguchi A, Tomoda H, Okuda S, Awaya J, Omura S. Cerulenin resistance in a cerulenin-producing fungus. Isolation of cerulenin insensitive fatty acid synthetase. Arch Biochem Biophys 1979; 197:30-5. [PMID: 575612 DOI: 10.1016/0003-9861(79)90214-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Broglie RM, Niederman RA. Membranes of Rhodopseudomonas sphaeroides: effect of cerulenin on assembly of chromatophore membrane. J Bacteriol 1979; 138:788-98. [PMID: 313392 PMCID: PMC218106 DOI: 10.1128/jb.138.3.788-798.1979] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The effects of cerulenin were investigated in Rhodopseudomonas sphaeroides to elucidate further the mechanisms controlling the assembly of the chromatophore membrane. When this potent inhibitor of fatty acid biosynthesis was added to photosynthetically grown cultures, there was an immediate cessation of phospholipid, bacteriochlorophyll a, carotenoid, and ubiquinone formation. Concurrently, there was also a marked decrease in the rate of incorporation of protein into the chromatophore membrane. In contrast, only a small decrease in the rate of soluble and cell envelope protein synthesis was observed and, in chemotrophically grown cells, protein continued to be incorporated into both the cytoplasmic and outer membranes. The removal of delta-aminolaevulinate from mutant H-5 of R. sphaeroides, which requires this porphyrin precursor, was reexamined to determine whether cerulenin-induced cessation of chromatophore protein incorporation was due solely to blocked bacteriochlorophyll a synthesis. In the deprived H-5 cells, inhibition of [35S]methionine incorporation into chromatophores was confined mainly to apoproteins of bacteriochlorophyll a complexes. Other minor chromatophore proteins continued to be inserted to a greater extent than in cerulenin-treated wild type where phospholipid synthesis has also ceased. These results indicated that the assembly of the chromatophore membrane is under strict regulatory control involving concomitant phospholipid, pigment, and protein syntheses.
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Caulfield MP, Berkeley RC, Pepper EA, Melling J. Export of extracellular levansucrase by Bacillus subtilis: inhibition by cerulenin and quinacrine. J Bacteriol 1979; 138:345-51. [PMID: 108256 PMCID: PMC218184 DOI: 10.1128/jb.138.2.345-351.1979] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacillus subtilis B secretes an inducible, extracellular enzyme, levansucrase. Inhibition studies were undertaken to investigate the possible mechanism of release of this enzyme. The antibiotic cerulenin, at a concentration of 10 micrograms/ml, totally inhibited de novo lipid synthesis in B. subtilis B for at least 1 h, while only slightly reducing protein and RNA synthesis. At this concentration cerulenin, added concomitantly with the inducer sucrose, prevented the release of levansucrase for at least 150 min. This was not due to the prevention of inducer uptake by the cells. The release of the enzyme was also independent of cell division. In B. subtilis 1007 the induction of beta-galactosidase by 5 mM lactose was not prevented by cerulenin. Preliminary evidence indicated the association of a lipid moiety with the enzyme as it passes through the cytoplasmic membrane. Quinacrine (0.2 mM), which inhibits the penicillinase-releasing protease of Bacillus licheniformis, inhibited levansucrase release from B. subtilis B, but had no effect on lipid synthesis.
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Lazdunski A, Murgier M, Lazdunski C. Phospholipid synthesis-dependent activity of aminopeptidase N in intact cells of Escherichia coli. J Mol Biol 1979; 128:127-41. [PMID: 107320 DOI: 10.1016/0022-2836(79)90122-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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