1
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Gudyka J, Ceja-Vega J, Krmic M, Porteus R, Lee S. The Role of Lipid Intrinsic Curvature in the Droplet Interface Bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:11428-11435. [PMID: 38764431 PMCID: PMC11155247 DOI: 10.1021/acs.langmuir.4c00270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/21/2024]
Abstract
Model bilayers are constructed from lipids having different intrinsic curvatures using the droplet interface bilayer (DIB) method, and their static physicochemical properties are determined. Geometrical and tensiometric measurements are used to derive the free energy of formation (ΔF) of a two-droplet DIB relative to a pair of isolated aqueous droplets, each decorated with a phospholipid monolayer. The lipid molecules employed have different headgroup sizes but identical hydrophobic tail structure, and each is characterized by an intrinsic curvature value (c0) that increases in absolute value with decreasing size of headgroup. Mixtures of lipids at different ratios were also investigated. The role of curvature stress on the values of ΔF of the respective lipid bilayers in these model membranes is discussed and is illuminated by the observation of a decrement in ΔF that scales as a near linear function of c02. Overall, the results reveal an association that should prove useful in studies of ion channels and other membrane proteins embedded in model droplet bilayer systems that will impact the understanding of protein function in cellular membranes composed of lipids of high and low curvature.
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Affiliation(s)
- Jamie Gudyka
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
| | - Jasmin Ceja-Vega
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
| | - Michael Krmic
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
| | - Riley Porteus
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
| | - Sunghee Lee
- Department of Chemistry and
Biochemistry, Iona University, New Rochelle, New York 10801, United States
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2
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Du X, Ma X, Gao Y. The physiological function of squalene and its application prospects in animal husbandry. Front Vet Sci 2024; 10:1284500. [PMID: 38292136 PMCID: PMC10824843 DOI: 10.3389/fvets.2023.1284500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 12/26/2023] [Indexed: 02/01/2024] Open
Abstract
Squalene, which is a natural triterpenoid unsaturated hydrocarbon, is abundant in shark liver and plant seeds. Squalene has various physiological functions such as being anti-inflammatory and antioxidant. This paper reviews the physiological functions of squalene and its application prospects in livestock and poultry production, with a view to providing a theoretical basis for its in-depth application in animal husbandry.
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Affiliation(s)
- Xin Du
- College of Life Science, Baicheng Normal University, Baicheng, China
| | - Xue Ma
- College of Life Science, Baicheng Normal University, Baicheng, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Yang Gao
- College of Life Science, Baicheng Normal University, Baicheng, China
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3
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LoRicco JG, Hoffmann I, Caliò A, Peters J. The membrane regulator squalane increases membrane rigidity under high hydrostatic pressure in archaeal membrane mimics. SOFT MATTER 2023; 19:6280-6286. [PMID: 37553974 DOI: 10.1039/d3sm00352c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Apolar lipids within the membranes of archaea are thought to play a role in membrane regulation. In this work we explore the effect of the apolar lipid squalane on the dynamics of a model archaeal-like membrane, under pressure, using neutron spin echo spectroscopy. To the best of our knowledge, this is the first report on membrane dynamics at high pressure using NSE spectroscopy. Increasing pressure leads to an increase in membrane rigidity, in agreement with other techniques. The presence of squalane in the membrane results in a stiffer membrane supporting its role as a membrane regulator.
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Affiliation(s)
| | | | - Antonino Caliò
- Université de Lyon, INSA Lyon, CNRS, MAP UMR 5240, Villeurbanne, France
| | - Judith Peters
- Institut Laue-Langevin, Grenoble, France.
- Univ. Grenoble Alpes, CNRS, LiPhy, Grenoble, France
- Institut Universitaire de France, 75231 Paris, France
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4
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Xu R, Song J, Ruze R, Chen Y, Yin X, Wang C, Zhao Y. SQLE promotes pancreatic cancer growth by attenuating ER stress and activating lipid rafts-regulated Src/PI3K/Akt signaling pathway. Cell Death Dis 2023; 14:497. [PMID: 37542052 PMCID: PMC10403582 DOI: 10.1038/s41419-023-05987-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 07/10/2023] [Accepted: 07/12/2023] [Indexed: 08/06/2023]
Abstract
Pancreatic cancer (PC), a highly lethal malignancy, commonly exhibits metabolic reprogramming that results in therapeutic vulnerabilities. Nevertheless, the mechanisms underlying the impacts of aberrant cholesterol metabolism on PC development and progression remain elusive. In this study, we found that squalene epoxidase (SQLE) is a crucial mediator of cholesterol metabolism in PC growth. We observed a profound upregulation of SQLE in PC tissues, and its high expression was correlated with poor patient outcomes. Our functional experiments demonstrated that SQLE facilitated cell proliferation, induced cell cycle progression, and inhibited apoptosis in vitro, while promoting tumor growth in vivo. Mechanistically, SQLE was found to have a dual role. First, its inhibition led to squalene accumulation-induced endoplasmic reticulum (ER) stress and subsequent apoptosis. Second, it enhanced de novo cholesterol biosynthesis and maintained lipid raft stability, thereby activating the Src/PI3K/Akt signaling pathway. Significantly, employing SQLE inhibitors effectively suppressed PC cell proliferation and xenograft tumor growth. In summary, this study reveals SQLE as a novel oncogene that promotes PC growth by mitigating ER stress and activating lipid raft-regulated Src/PI3K/Akt signaling pathway, highlighting the potential of SQLE as a therapeutic target for PC.
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Affiliation(s)
- Ruiyuan Xu
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
- Key Laboratory of Research in Pancreatic Tumor, Chinese Academy of Medical Sciences, Beijing, 100023, P. R. China
- National Science and Technology Key Infrastructure on Translational Medicine in Peking Union Medical College Hospital, Beijing, 100023, P. R. China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
| | - Jianlu Song
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
- Key Laboratory of Research in Pancreatic Tumor, Chinese Academy of Medical Sciences, Beijing, 100023, P. R. China
- National Science and Technology Key Infrastructure on Translational Medicine in Peking Union Medical College Hospital, Beijing, 100023, P. R. China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
| | - Rexiati Ruze
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
- Key Laboratory of Research in Pancreatic Tumor, Chinese Academy of Medical Sciences, Beijing, 100023, P. R. China
- National Science and Technology Key Infrastructure on Translational Medicine in Peking Union Medical College Hospital, Beijing, 100023, P. R. China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
| | - Yuan Chen
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
- Key Laboratory of Research in Pancreatic Tumor, Chinese Academy of Medical Sciences, Beijing, 100023, P. R. China
- National Science and Technology Key Infrastructure on Translational Medicine in Peking Union Medical College Hospital, Beijing, 100023, P. R. China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
| | - Xinpeng Yin
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
- Key Laboratory of Research in Pancreatic Tumor, Chinese Academy of Medical Sciences, Beijing, 100023, P. R. China
- National Science and Technology Key Infrastructure on Translational Medicine in Peking Union Medical College Hospital, Beijing, 100023, P. R. China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China
| | - Chengcheng Wang
- Key Laboratory of Research in Pancreatic Tumor, Chinese Academy of Medical Sciences, Beijing, 100023, P. R. China.
- National Science and Technology Key Infrastructure on Translational Medicine in Peking Union Medical College Hospital, Beijing, 100023, P. R. China.
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China.
- Medical Science Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China.
| | - Yupei Zhao
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China.
- Key Laboratory of Research in Pancreatic Tumor, Chinese Academy of Medical Sciences, Beijing, 100023, P. R. China.
- National Science and Technology Key Infrastructure on Translational Medicine in Peking Union Medical College Hospital, Beijing, 100023, P. R. China.
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100023, P. R. China.
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5
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Incorporation and localisation of alkanes in a protomembrane model by neutron diffraction. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184119. [PMID: 36638951 DOI: 10.1016/j.bbamem.2023.184119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/15/2022] [Accepted: 01/03/2023] [Indexed: 01/11/2023]
Abstract
Protomembranes at the origin of life were likely composed of short-chain lipids, readily available on the early Earth. Membranes formed by such lipids are less stable and more permeable under extreme conditions, so a novel membrane architecture was suggested to validate the accuracy of this assumption. The model membrane includes the presence of a layer of alkanes in the mid-plane of the protomembrane in between the two monolayer leaflets and lying perpendicular to the lipid acyl chains. Here, we investigated such a possibility experimentally for membranes formed by the short-chain phospholipid 1,2-didecanoyl-sn-glycero-3-phophocholine, including or not the alkanes eicosane, squalane or triacontane by means of neutron membrane diffraction and contrast variation. We found strong indications for incorporation of two of the three alkanes in the membrane mid-plane through the determination of neutron scattering length density profiles with hydrogenated vs deuterated alkanes and membrane swelling at various relative humidities indicating a slightly increased bilayer thickness when the alkanes are incorporated into the bilayers. The selectivity of the incorporation points out the role of the length of the n-alkanes with respect to the capacity of the membrane to incorporate them.
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6
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Coates HW, Capell-Hattam IM, Olzomer EM, Du X, Farrell R, Yang H, Byrne FL, Brown AJ. Hypoxia truncates and constitutively activates the key cholesterol synthesis enzyme squalene monooxygenase. eLife 2023; 12:82843. [PMID: 36655986 PMCID: PMC9851614 DOI: 10.7554/elife.82843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 12/13/2022] [Indexed: 01/20/2023] Open
Abstract
Cholesterol synthesis is both energy- and oxygen-intensive, yet relatively little is known of the regulatory effects of hypoxia on pathway enzymes. We previously showed that the rate-limiting and first oxygen-dependent enzyme of the committed cholesterol synthesis pathway, squalene monooxygenase (SM), can undergo partial proteasomal degradation that renders it constitutively active. Here, we show hypoxia is a physiological trigger for this truncation, which occurs through a two-part mechanism: (1) increased targeting of SM to the proteasome via stabilization of the E3 ubiquitin ligase MARCHF6 and (2) accumulation of the SM substrate, squalene, which impedes the complete degradation of SM and liberates its truncated form. This preserves SM activity and downstream pathway flux during hypoxia. These results uncover a feedforward mechanism that allows SM to accommodate fluctuating substrate levels and may contribute to its widely reported oncogenic properties.
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Affiliation(s)
- Hudson W Coates
- School of Biotechnology and Biomolecular Sciences, UNSW SydneySydneyAustralia
| | | | - Ellen M Olzomer
- School of Biotechnology and Biomolecular Sciences, UNSW SydneySydneyAustralia
| | - Ximing Du
- School of Biotechnology and Biomolecular Sciences, UNSW SydneySydneyAustralia
| | - Rhonda Farrell
- Prince of Wales Private HospitalRandwickAustralia
- Chris O’Brien LifehouseCamperdownAustralia
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, UNSW SydneySydneyAustralia
| | - Frances L Byrne
- School of Biotechnology and Biomolecular Sciences, UNSW SydneySydneyAustralia
| | - Andrew J Brown
- School of Biotechnology and Biomolecular Sciences, UNSW SydneySydneyAustralia
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7
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Scheidegger L, Stricker L, Beltramo PJ, Vermant J. Domain Size Regulation in Phospholipid Model Membranes Using Oil Molecules and Hybrid Lipids. J Phys Chem B 2022; 126:5842-5854. [PMID: 35895895 PMCID: PMC9377339 DOI: 10.1021/acs.jpcb.2c02862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/06/2022] [Indexed: 11/29/2022]
Abstract
The formation of domains in multicomponent lipid mixtures has been suggested to play a role in moderating signal transduction in cells. Understanding how domain size may be regulated by both hybrid lipid molecules and impurities is important for understanding real biological processes; at the same time, developing model systems where domain size can be regulated is crucial to enable systematic studies of domain formation kinetics and thermodynamics. Here, we perform a model study of the effects of oil molecules, which swell the bilayer, and line-active hybrid phospholipids using a thermally induced liquid-solid phase separation in planar, free-standing lipid bilayers consisting of DOPC and DPPC (1,2-dioleoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, respectively). The experiments show that the kinetics of domain growth are significantly affected by the type and molecular structure of the oil (squalene, hexadecane, or decane), with the main contributing factors being the degree of swelling of the bilayer and the changes in line tension induced by the different oils, with smaller domains resulting from systems with smaller values of the line tension. POPC (1-palmitoyl-sn-2-oleoyl-glycero-3-phosphocholine), on the other hand, acts as a line-active hybrid lipid, reducing the domain size when added in small amounts and slowing down domain coarsening. Finally, we show that despite the regulation of domain size by both methods, the phase transition temperature is influenced by the presence of oil molecules but not significantly by the presence of hybrid lipids. Overall, our results show how to regulate domain size in binary membrane model systems, over a wide range of length scales, by incorporating oil molecules and hybrid lipids.
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Affiliation(s)
- Laura Scheidegger
- Department
of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Laura Stricker
- Department
of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Peter J. Beltramo
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Jan Vermant
- Department
of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
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8
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Hong Z, Liu T, Wan L, Fa P, Kumar P, Cao Y, Prasad CB, Qiu Z, Joseph L, Hongbing W, Li Z, Wang QE, Guo P, Guo D, Yilmaz AS, Lu L, Papandreou I, Jacob NK, Yan C, Zhang X, She QB, Ma Z, Zhang J. Targeting Squalene Epoxidase Interrupts Homologous Recombination via the ER Stress Response and Promotes Radiotherapy Efficacy. Cancer Res 2022; 82:1298-1312. [PMID: 35045984 PMCID: PMC8983553 DOI: 10.1158/0008-5472.can-21-2229] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/03/2021] [Accepted: 01/10/2022] [Indexed: 11/16/2022]
Abstract
Over 50% of all patients with cancer are treated with radiotherapy. However, radiotherapy is often insufficient as a monotherapy and requires a nontoxic radiosensitizer. Squalene epoxidase (SQLE) controls cholesterol biosynthesis by converting squalene to 2,3-oxidosqualene. Given that SQLE is frequently overexpressed in human cancer, this study investigated the importance of SQLE in breast cancer and non-small cell lung cancer (NSCLC), two cancers often treated with radiotherapy. SQLE-positive IHC staining was observed in 68% of breast cancer and 56% of NSCLC specimens versus 15% and 25% in normal breast and lung tissue, respectively. Importantly, SQLE expression was an independent predictor of poor prognosis, and pharmacologic inhibition of SQLE enhanced breast and lung cancer cell radiosensitivity. In addition, SQLE inhibition enhanced sensitivity to PARP inhibition. Inhibition of SQLE interrupted homologous recombination by suppressing ataxia-telangiectasia mutated (ATM) activity via the translational upregulation of wild-type p53-induced phosphatase (WIP1), regardless of the p53 status. SQLE inhibition and subsequent squalene accumulation promoted this upregulation by triggering the endoplasmic reticulum (ER) stress response. Collectively, these results identify a novel tumor-specific radiosensitizer by revealing unrecognized cross-talk between squalene metabolites, ER stress, and the DNA damage response. Although SQLE inhibitors have been used as antifungal agents in the clinic, they have not yet been used as antitumor agents. Repurposing existing SQLE-inhibiting drugs may provide new cancer treatments. SIGNIFICANCE Squalene epoxidase inhibitors are novel tumor-specific radiosensitizers that promote ER stress and suppress homologous recombination, providing a new potential therapeutic approach to enhance radiotherapy efficacy.
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Affiliation(s)
- Zhipeng Hong
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
- Department of Breast Surgery, Affiliated Quanzhou First Hospital of Fujian Medical University, Quanzhou, Fujian, 362000, P.R. China
| | - Tao Liu
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Lingfeng Wan
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Pengyan Fa
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Pankaj Kumar
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Yanan Cao
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40506, USA
| | - Chandra Bhushan Prasad
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Zhaojun Qiu
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Liu Joseph
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Wang Hongbing
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland, USA
| | - Zaibo Li
- Department of Pathology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Qi-En Wang
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Peixuan Guo
- Center for RNA Nanobiotechnology and Nanomedicine, The Ohio State University, Columbus, OH, USA
| | - Deliang Guo
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Ayse Selen Yilmaz
- Department of Biomedical Informatics, College of Medicine, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, USA
| | - Lanchun Lu
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Ioanna Papandreou
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Naduparambil K Jacob
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
| | - Chunhong Yan
- Georgia Cancer Center, Augusta University, Augusta, GA, USA
| | - Xiaoli Zhang
- Department of Biomedical Informatics, College of Medicine, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, USA
| | - Qing-Bai She
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, 40506, USA
| | - Zhefu Ma
- Department Breast Surgery and Plastic Surgery, Cancer Hospital of China Medical University, 44 Xiaoheyan Road, Dadong District, Shenyang, 110042, China
- Department Breast & Thyroid Surgery, The First Affiliated Hospital, Sun Yat-sen University, No.58 of Zhongshan 2nd Road, Yuexiu District, Guangzhou, 510080, China
| | - Junran Zhang
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, OH, 43210, USA
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9
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Fader Kaiser CM, Romano PS, Vanrell MC, Pocognoni CA, Jacob J, Caruso B, Delgui LR. Biogenesis and Breakdown of Lipid Droplets in Pathological Conditions. Front Cell Dev Biol 2022; 9:826248. [PMID: 35198567 PMCID: PMC8860030 DOI: 10.3389/fcell.2021.826248] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/22/2021] [Indexed: 12/17/2022] Open
Abstract
Lipid droplets (LD) have long been considered as mere fat drops; however, LD have lately been revealed to be ubiquitous, dynamic and to be present in diverse organelles in which they have a wide range of key functions. Although incompletely understood, the biogenesis of eukaryotic LD initiates with the synthesis of neutral lipids (NL) by enzymes located in the endoplasmic reticulum (ER). The accumulation of NL leads to their segregation into nanometric nuclei which then grow into lenses between the ER leaflets as they are further filled with NL. The lipid composition and interfacial tensions of both ER and the lenses modulate their shape which, together with specific ER proteins, determine the proneness of LD to bud from the ER toward the cytoplasm. The most important function of LD is the buffering of energy. But far beyond this, LD are actively integrated into physiological processes, such as lipid metabolism, control of protein homeostasis, sequestration of toxic lipid metabolic intermediates, protection from stress, and proliferation of tumours. Besides, LD may serve as platforms for pathogen replication and defense. To accomplish these functions, from biogenesis to breakdown, eukaryotic LD have developed mechanisms to travel within the cytoplasm and to establish contact with other organelles. When nutrient deprivation occurs, LD undergo breakdown (lipolysis), which begins with the LD-associated members of the perilipins family PLIN2 and PLIN3 chaperone-mediated autophagy degradation (CMA), a specific type of autophagy that selectively degrades a subset of cytosolic proteins in lysosomes. Indeed, PLINs CMA degradation is a prerequisite for further true lipolysis, which occurs via cytosolic lipases or by lysosome luminal lipases when autophagosomes engulf portions of LD and target them to lysosomes. LD play a crucial role in several pathophysiological processes. Increased accumulation of LD in non-adipose cells is commonly observed in numerous infectious diseases caused by intracellular pathogens including viral, bacterial, and parasite infections, and is gradually recognized as a prominent characteristic in a variety of cancers. This review discusses current evidence related to the modulation of LD biogenesis and breakdown caused by intracellular pathogens and cancer.
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Affiliation(s)
- Claudio M Fader Kaiser
- CONICET Dr. Mario H. Burgos Institute of Histology and Embryology (IHEM), Mendoza, Argentina
| | - Patricia S Romano
- CONICET Dr. Mario H. Burgos Institute of Histology and Embryology (IHEM), Mendoza, Argentina
| | - M Cristina Vanrell
- CONICET Dr. Mario H. Burgos Institute of Histology and Embryology (IHEM), Mendoza, Argentina
| | - Cristian A Pocognoni
- CONICET Dr. Mario H. Burgos Institute of Histology and Embryology (IHEM), Mendoza, Argentina
| | - Julieta Jacob
- CONICET Dr. Mario H. Burgos Institute of Histology and Embryology (IHEM), Mendoza, Argentina
| | - Benjamín Caruso
- Instituto de Investigaciones Biologicas y Tecnologicas, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Cordoba, Cordoba, Argentina
| | - Laura R Delgui
- CONICET Dr. Mario H. Burgos Institute of Histology and Embryology (IHEM), Mendoza, Argentina
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10
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Ataeian M, Vadlamani A, Haines M, Mosier D, Dong X, Kleiner M, Strous M, Hawley AK. Proteome and strain analysis of cyanobacterium Candidatus "Phormidium alkaliphilum" reveals traits for success in biotechnology. iScience 2021; 24:103405. [PMID: 34877483 PMCID: PMC8633866 DOI: 10.1016/j.isci.2021.103405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/27/2021] [Accepted: 11/03/2021] [Indexed: 11/18/2022] Open
Abstract
Cyanobacteria encompass a diverse group of photoautotrophic bacteria with important roles in nature and biotechnology. Here we characterized Candidatus “Phormidium alkaliphilum,” an abundant member in alkaline soda lake microbial communities globally. The complete, circular whole-genome sequence of Ca. “P. alkaliphilum” was obtained using combined Nanopore and Illumina sequencing of a Ca. “P. alkaliphilum” consortium. Strain-level diversity of Ca. “P. alkaliphilum” was shown to contribute to photobioreactor robustness under different operational conditions. Comparative genomics of closely related species showed that adaptation to high pH was not attributed to specific genes. Proteomics at high and low pH showed only minimal changes in gene expression, but higher productivity in high pH. Diverse photosystem antennae proteins, and high-affinity terminal oxidase, compared with other soda lake cyanobacteria, appear to contribute to the success of Ca. “P. alkaliphilum” in photobioreactors and biotechnology applications. Closed genome of the cyanobacteria Ca. P. alkaliphilum from high-pH photobioreactor Genetic factors lead this Phormidium to outcompete other cyanobacteria in photobioreactor Adaptation to high pH and alkalinity is not linked to specific genes Strain-level diversity contributes Ca. P. alkaliphilum success in changing conditions
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Affiliation(s)
- Maryam Ataeian
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | | | - Marianne Haines
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Damon Mosier
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Xiaoli Dong
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Alyse K. Hawley
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
- School of Engineering, University of British Columbia Okanagan, Kelowna, BC, Canada
- Corresponding author
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11
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Toopkanloo SP, Tan TB, Cheong LZ, Liu Y, Tan CP. In vitro applicability of mixed soy lecithin-based liposomes with added several lipophilic agents as novel delivery systems for delivery of quercetin. J DISPER SCI TECHNOL 2021. [DOI: 10.1080/01932691.2021.2013865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Sahar Pakbaten Toopkanloo
- Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM, Serdang, Selangor, Malaysia
| | - Tai Boon Tan
- Department of Food Service and Management, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM, Serdang, Selangor, Malaysia
| | - Ling-Zhi Cheong
- Department of Food Science and Engineering, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
- Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, College of Food and Pharmaceutical Science, Ningbo University, Ningbo, China
| | - Yuanfa Liu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, National Engineering Research Center for Functional Food, National Engineering Laboratory for Cereal Fermentation Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Jiangnan, China
| | - Chin Ping Tan
- Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM, Serdang, Selangor, Malaysia
- Laboratory of Processing and Product Development, Institute of Plantation Studies, Universiti Putra Malaysia, UPM, , Serdang, Selangor, Malaysia
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12
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Hagi K, Hasegawa T, Yamamoto T, Tomihari M, Fujimoto Y, Sakamoto Y, Sawa S. Corneal protective effects of novel tear substitutes containing sodium hyaluronate and dodecahydrosqualene, squalane, in a porcine dry eye model. J Vet Med Sci 2021; 84:94-101. [PMID: 34789590 PMCID: PMC8810329 DOI: 10.1292/jvms.21-0496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
To develop a novel tear substitute (TS) containing sodium hyaluronate (SH) and dodecahydrosqualene (DHS, squalane), we improved the prescription of a previously developed TS containing
saline, 0.5% SH and 1% castor oil (CO), which had corneal protective effects against 60-min desiccation in a porcine dry eye model and viscosity of 106.8 mPa·S. Fresh porcine eyes were
treated with a TS containing saline, 0.1%, 0.25%, 0.3% or 0.5% SH, and 1% CO or 1%, 2.5% or 5% DHS, and TS-treated eyes were desiccated for up to 180 min. The corneal damage was evaluated by
the staining score of methylene blue (MB), absorbance of MB extracted from the cornea, the staining density of lissamine green (LG) and histopathology. The viscosities of the examined TS
were also measured. A saline/0.5% SH/1% DHS solution had corneal protective effects for 90 min under desiccation and a viscosity of 110.0 mPa·s. A TS with saline, 0.1%, 0.25% or 0.3% SH and
1% or 2.5% DHS did not have better protective effects than a saline/0.5% SH/1% DHS solution, although a saline/0.3% SH/5% DHS solution exhibited greater corneal protection against 180-min
desiccation on MB and LG staining and histopathological examination, and its viscosity was 34.5 mPa·s, which was similar to the 29.5 mPa·s of 0.3% SH. The saline/0.3% SH/5% DHS solution is
available as a novel 3-hr long-lasting TS containing mucinomimetic and liquid oil components to treat and relieve dry eye symptoms in animals and humans.
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Affiliation(s)
- Kiyomi Hagi
- Osaka Prefecture University Veterinary Medical Center, Osaka Prefecture University
| | - Takashi Hasegawa
- Department of Advanced Clinical Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Takeshi Yamamoto
- Department of Advanced Clinical Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Mizuki Tomihari
- Department of Advanced Clinical Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Yuka Fujimoto
- Department of Advanced Clinical Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University
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13
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Caruso B, Wilke N, Perillo MA. Triglyceride Lenses at the Air-Water Interface as a Model System for Studying the Initial Stage in the Biogenesis of Lipid Droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:10958-10970. [PMID: 34491757 DOI: 10.1021/acs.langmuir.1c01359] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Lipid droplets (LD) are intracellular structures consisting of an apolar lipid core, composed mainly of triglycerides (TG) and steryl esters, coated by a lipid-protein mixed monolayer. The mechanisms underlying LD biogenesis at the endoplasmic reticulum membrane are a matter of many current investigations. Although models explaining the budding-off of protuberances of phase-segregated TG inside bilayers have been proposed recently, the assumption of such initial blisters needs further empirical support. Here, we study mixtures of egg phosphatidylcholine (EPC) and TG at the air-water interface in order to describe some physical properties and topographic stability of TG bulk structures in contact with interfaces. Brewster angle microscopy images revealed the appearance of microscopic collapsed structures (CS) with highly reproducible lateral size (∼1 μm lateral radius) not varying with lateral packing changes and being highly stable at surface pressures (π) beyond collapse. By surface spectral fluorescence microscopy, we were able to characterize the solvatochromism of Nile Red both in monolayers and inside CS. This allowed to conclude that CS corresponded to a phase of liquid TG and to characterize them as lenses forming a three-phase (oil-water-air) system. Thereby, the thicknesses of the lenses could be determined, observing that they were dramatically flattened when EPC was present (6-12 nm compared to 30-50 nm for lenses on EPC/TG and TG films, respectively). Considering the shape of lenses, the interfacial tensions, and the Neumann's triangle, this experimental approach allows one to estimate the oil-water interfacial tension acting at each individual microscopic lens and at varying compression states of the surrounding monolayer. Thus, lenses formed on air-water Langmuir films can serve to assess variables of relevance to the initial step of LD biogenesis, such as the degree of dispersion of excluded-TG phase and shape, spatial distribution, and oil-water interfacial tension of lenses.
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Affiliation(s)
- B Caruso
- Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química, Cátedra de Química BiológicaUniversidad Nacional de Córdoba, X5016GCA Córdoba, Argentina
- Instituto de Investigaciones Biológicas y Tecnológicas (IIByT), CONICET, X5016GCA Córdoba, Argentina
| | - N Wilke
- Facultad de Ciencias Químicas,. Departamento de Química Biológica Ranwel Caputto, Universidad Nacional de Córdoba, X5016GCA Córdoba, Argentina
- Centro de Investigaciones en Quimica Biológica de Córdoba (CIQUIBIC), CONICET, X5016GCA Córdoba, Argentina
| | - M A Perillo
- Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química, Cátedra de Química BiológicaUniversidad Nacional de Córdoba, X5016GCA Córdoba, Argentina
- Instituto de Investigaciones Biológicas y Tecnológicas (IIByT), CONICET, X5016GCA Córdoba, Argentina
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14
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Hu J, Cochrane WG, Jones AX, Blackmond DG, Paegel BM. Chiral lipid bilayers are enantioselectively permeable. Nat Chem 2021; 13:786-791. [PMID: 34112989 PMCID: PMC8325640 DOI: 10.1038/s41557-021-00708-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 04/16/2021] [Indexed: 12/17/2022]
Abstract
Homochiral membrane bilayers organize biological functions in all domains of life. The membrane’s permeability–its key property–correlates with a molecule’s lipophilicity, but the role of the membrane’s rich and uniform stereochemistry as a permeability determinant is largely ignored in empirical and computational measurements. Here, we describe a new approach to measuring permeation using continuously generated microfluidic droplet interface bilayers (DIBs, 480/min) and benchmark this system by monitoring fluorescent dye DIB permeation over time. Permeation of non-fluorescent, alkyne-labeled molecules was measured using a fluorogenic click reaction. DIB transport measurements revealed enantioselective permeation of alkyne-labeled amino acids (Ala, Val, Phe, Pro) and dipeptides through a chiral phospholipid bilayer; the biological L enantiomers permeated faster than D (1.2–6-fold; Ala–Pro). Enantioselective permeation both poses a potentially unanticipated criterion for drug design and offers a kinetic mechanism for the abiotic emergence of homochirality via chiral transfer between sugars, amino acids, and lipids.
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Affiliation(s)
- Juan Hu
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA
| | - Wesley G Cochrane
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA
| | | | | | - Brian M Paegel
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA. .,Departments of Chemistry and Biomedical Engineering, University of California, Irvine, CA, USA.
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15
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Non-Polar Lipids as Regulators of Membrane Properties in Archaeal Lipid Bilayer Mimics. Int J Mol Sci 2021; 22:ijms22116087. [PMID: 34200063 PMCID: PMC8200183 DOI: 10.3390/ijms22116087] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 11/17/2022] Open
Abstract
The modification of archaeal lipid bilayer properties by the insertion of apolar molecules in the lipid bilayer midplane has been proposed to support cell membrane adaptation to extreme environmental conditions of temperature and hydrostatic pressure. In this work, we characterize the insertion effects of the apolar polyisoprenoid squalane on the permeability and fluidity of archaeal model membrane bilayers, composed of lipid analogues. We have monitored large molecule and proton permeability and Laurdan generalized polarization from lipid vesicles as a function of temperature and hydrostatic pressure. Even at low concentration, squalane (1 mol%) is able to enhance solute permeation by increasing membrane fluidity, but at the same time, to decrease proton permeability of the lipid bilayer. The squalane physicochemical impact on membrane properties are congruent with a possible role of apolar intercalants on the adaptation of Archaea to extreme conditions. In addition, such intercalant might be used to cheaply create or modify chemically resistant liposomes (archeaosomes) for drug delivery.
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16
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Salvador-Castell M, Golub M, Erwin N, Demé B, Brooks NJ, Winter R, Peters J, Oger PM. Characterisation of a synthetic Archeal membrane reveals a possible new adaptation route to extreme conditions. Commun Biol 2021; 4:653. [PMID: 34079059 PMCID: PMC8172549 DOI: 10.1038/s42003-021-02178-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 04/29/2021] [Indexed: 02/04/2023] Open
Abstract
It has been proposed that adaptation to high temperature involved the synthesis of monolayer-forming ether phospholipids. Recently, a novel membrane architecture was proposed to explain the membrane stability in polyextremophiles unable to synthesize such lipids, in which apolar polyisoprenoids populate the bilayer midplane and modify its physico-chemistry, extending its stability domain. Here, we have studied the effect of the apolar polyisoprenoid squalane on a model membrane analogue using neutron diffraction, SAXS and fluorescence spectroscopy. We show that squalane resides inside the bilayer midplane, extends its stability domain, reduces its permeability to protons but increases that of water, and induces a negative curvature in the membrane, allowing the transition to novel non-lamellar phases. This membrane architecture can be transposed to early membranes and could help explain their emergence and temperature tolerance if life originated near hydrothermal vents. Transposed to the archaeal bilayer, this membrane architecture could explain the tolerance to high temperature in hyperthermophiles which grow at temperatures over 100 °C while having a membrane bilayer. The induction of a negative curvature to the membrane could also facilitate crucial cell functions that require high bending membranes.
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Affiliation(s)
| | - Maksym Golub
- Université Grenoble Alpes, CNRS, LiPhy, Grenoble, France
- Institut Laue Langevin, Grenoble, France
| | - Nelli Erwin
- Faculty of Chemistry and Chemical Biology, Technische Universität Dortmund, Dortmund, Germany
| | - Bruno Demé
- Institut Laue Langevin, Grenoble, France
| | | | - Roland Winter
- Faculty of Chemistry and Chemical Biology, Technische Universität Dortmund, Dortmund, Germany
| | - Judith Peters
- Université Grenoble Alpes, CNRS, LiPhy, Grenoble, France.
- Institut Laue Langevin, Grenoble, France.
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17
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Toopkanloo SP, Tan TB, Abas F, Azam M, Nehdi IA, Tan CP. Improving Vesicular Integrity and Antioxidant Activity of Novel Mixed Soy Lecithin-Based Liposomes Containing Squalene and Their Stability against UV Light. Molecules 2020; 25:E5873. [PMID: 33322600 PMCID: PMC7764204 DOI: 10.3390/molecules25245873] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 11/18/2022] Open
Abstract
In order to improve the membrane lipophilicity and the affinity towards the environment of lipid bilayers, squalene (SQ) could be conjugated to phospholipids in the formation of liposomes. The effect of membrane composition and concentrations on the degradation of liposomes prepared via the extrusion method was investigated. Liposomes were prepared using a mixture of SQ, cholesterol (CH) and Tween80 (TW80). Based on the optimal conditions, liposome batches were prepared in the absence and presence of SQ. Their physicochemical and stability behavior were evaluated as a function of liposome constituent. From the optimization study, the liposomal formulation containing 5% (w/w) mixed soy lecithin (ML), 0.5% (w/w) SQ, 0.3% (w/w) CH and 0.75% (w/w) TW80 had optimal physicochemical properties and displayed a unilamellar structure. Liposome prepared using the optimal formulation had a low particle size (158.31 ± 2.96 nm) and acceptable %increase in the particle size (15.09% ± 3.76%) and %trolox equivalent antioxidant capacity (%TEAC) loss (35.69% ± 0.72%) against UV light treatment (280-320 nm) for 6 h. The interesting outcome of this research was the association of naturally occurring substance SQ for size reduction without the extra input of energy or mechanical procedures, and improvement of vesicle stability and antioxidant activity of ML-based liposome. This study also demonstrated that the presence of SQ in the membrane might increase the acyl chain dynamics and decrease the viscosity of the dispersion, thereby limiting long-term stability of the liposome.
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Affiliation(s)
- Sahar Pakbaten Toopkanloo
- Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia;
| | - Tai Boon Tan
- Department of Food Service and Management, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM, Serdang 43400, Selangor, Malaysia;
| | - Faridah Abas
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM, Serdang 43400, Selangor, Malaysia;
| | - Mohammad Azam
- Chemistry Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; (M.A.); (I.A.N.)
| | - Imededdine Arbi Nehdi
- Chemistry Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; (M.A.); (I.A.N.)
- Chemistry Department, El Manar Preparatory Institute for Engineering Studies, Tunis El Manar University, P.O. Box 244, Tunis 2092, Tunisia
| | - Chin Ping Tan
- Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia;
- Laboratory of Processing and Product Development, Institute of Plantation Studies, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
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18
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Sorokin DY, Mosier D, Zorz JK, Dong X, Strous M. Wenzhouxiangella Strain AB-CW3, a Proteolytic Bacterium From Hypersaline Soda Lakes That Preys on Cells of Gram-Positive Bacteria. Front Microbiol 2020; 11:597686. [PMID: 33281797 PMCID: PMC7691419 DOI: 10.3389/fmicb.2020.597686] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/26/2020] [Indexed: 11/13/2022] Open
Abstract
A new haloalkaliphilic species of Wenzhouxiangella, strain AB-CW3, was isolated from a system of hypersaline alkaline soda lakes in the Kulunda Steppe using cells of Staphylococcus aureus as growth substrate. AB-CW3's complete, circular genome was assembled from combined nanopore and Illumina sequencing and its proteome was determined for three different experimental conditions. AB-CW3 is an aerobic gammaproteobacterium feeding mainly on proteins and peptides. Unique among Wenzhouxiangella, it uses a flagellum for motility, fimbria for cell attachment and is capable of complete denitrification. AB-CW3 can use proteins derived from living or dead cells of Staphylococcus and other Gram-positive bacteria as the carbon and energy source. It encodes and expresses production of a novel Lantibiotic, a class of antimicrobial peptides which have so far only been found to be produced by Gram-positive bacteria. AB-CW3 likely excretes this peptide via a type I secretion system encoded upstream of the genes for production of the Lanthipeptide. Comparison of AB-CW3's genome to 18 other Wenzhouxiangella genomes from marine, hypersaline, and soda lake habitats indicated one or two transitions from marine to soda lake environments followed by a transition of W. marina back to the oceans. Only 19 genes appear to set haloalkaliphilic Wenzhouxiangella apart from their neutrophilic relatives. As strain AB-CW3 is only distantly related to other members of the genus, we propose to provisionally name it "Wenzhouxiangella alkaliphila".
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Affiliation(s)
- Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Federal Research Centre for Biotechnology, Russian Academy of Sciences, Moscow, Russia.,Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Damon Mosier
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Jackie K Zorz
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Xiaoli Dong
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
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19
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LoRicco JG, Salvador-Castell M, Demé B, Peters J, Oger PM. Apolar Polyisoprenoids Located in the Midplane of the Bilayer Regulate the Response of an Archaeal-Like Membrane to High Temperature and Pressure. Front Chem 2020; 8:594039. [PMID: 33282836 PMCID: PMC7689154 DOI: 10.3389/fchem.2020.594039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/13/2020] [Indexed: 01/02/2023] Open
Abstract
Archaea are known to inhabit some of the most extreme environments on Earth. The ability of archaea possessing membrane bilayers to adapt to high temperature (>85°C) and high pressure (>1,000 bar) environments is proposed to be due to the presence of apolar polyisoprenoids at the midplane of the bilayer. In this work, we study the response of this novel membrane architecture to both high temperature and high hydrostatic pressure using neutron diffraction. A mixture of two diether, phytanyl chain lipids (DoPhPC and DoPhPE) and squalane was used to model this novel architecture. Diffraction data indicate that at high temperatures a stable coexistence of fluid lamellar phases exists within the membrane and that stable coexistence of these phases is also possible at high pressure. Increasing the amount of squalane in the membrane regulates the phase separation with respect to both temperature and pressure, and also leads to an increase in the lamellar repeat spacing. The ability of squalane to regulate the ultrastructure of an archaea-like membrane at high pressure and temperature supports the hypothesis that archaea can use apolar lipids as an adaptive mechanism to extreme conditions.
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Affiliation(s)
| | | | - Bruno Demé
- Department of Large Scale Structures, Institut Laue-Langevin, Grenoble, France
| | - Judith Peters
- Department of Large Scale Structures, Institut Laue-Langevin, Grenoble, France
- Department of Spectroscopy, Université Grenoble Alpes, LiPhy, Grenoble, France
| | - Philippe M. Oger
- Univ Lyon, INSA de Lyon, CNRS, MAP UMR 5240, Villeurbanne, France
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20
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Salvador-Castell M, Demé B, Oger P, Peters J. Lipid Phase Separation Induced by the Apolar Polyisoprenoid Squalane Demonstrates Its Role in Membrane Domain Formation in Archaeal Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:7375-7382. [PMID: 32515591 DOI: 10.1021/acs.langmuir.0c00901] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Archaea synthesize methyl-branched, ether phospholipids, which confer the archaeal membrane exceptional physicochemical properties. A novel membrane organization was proposed recently to explain the thermal and high pressure tolerance of the polyextremophilic archaeon Thermococcus barophilus. According to this theoretical model, apolar molecules could populate the midplane of the bilayer and could alter the physicochemical properties of the membrane, among which is the possibility to form membrane domains. We tested this hypothesis using neutron diffraction on a model archaeal membrane composed of two archaeal diether lipids with phosphocholine and phosphoethanolamine headgroups in the presence of the apolar polyisoprenoid squalane. We show that squalane is inserted in the midplane at a maximal concentration between 5 and 10 mol % and that squalane can modify the lateral organization of the membrane and induces the coexistence of separate phases. The lateral reorganization is temperature- and squalane concentration-dependent and could be due to the release of lipid chain frustration and the induction of a negative curvature in the lipids.
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Affiliation(s)
| | - Bruno Demé
- Institut Laue Langevin, Grenoble Cedex 9 F-38042, France
| | - Phil Oger
- INSA Lyon, Université de Lyon, CNRS, UMR5240, Villeurbanne 69621, France
| | - Judith Peters
- Institut Laue Langevin, Grenoble Cedex 9 F-38042, France
- Univ. Grenoble Alpes, CNRS, LIPhy, Grenoble 38000, France
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21
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A key mammalian cholesterol synthesis enzyme, squalene monooxygenase, is allosterically stabilized by its substrate. Proc Natl Acad Sci U S A 2020; 117:7150-7158. [PMID: 32170014 PMCID: PMC7132291 DOI: 10.1073/pnas.1915923117] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cholesterol biosynthesis is a high-cost process and, therefore, tightly regulated by both transcriptional and posttranslational negative feedback mechanisms in response to the level of cellular cholesterol. Squalene monooxygenase (SM, also known as squalene epoxidase or SQLE) is a rate-limiting enzyme in the cholesterol biosynthetic pathway and catalyzes epoxidation of squalene. The stability of SM is negatively regulated by cholesterol via its N-terminal regulatory domain (SM-N100). In this study, using a SM-luciferase fusion reporter cell line, we performed a chemical genetics screen that identified inhibitors of SM itself as up-regulators of SM. This effect was mediated through the SM-N100 region, competed with cholesterol-accelerated degradation, and required the E3 ubiquitin ligase MARCH6. However, up-regulation was not observed with statins, well-established cholesterol biosynthesis inhibitors, and this pointed to the presence of another mechanism other than reduced cholesterol synthesis. Further analyses revealed that squalene accumulation upon treatment with the SM inhibitor was responsible for the up-regulatory effect. Using photoaffinity labeling, we demonstrated that squalene directly bound to the N100 region, thereby reducing interaction with and ubiquitination by MARCH6. Our findings suggest that SM senses squalene via its N100 domain to increase its metabolic capacity, highlighting squalene as a feedforward factor for the cholesterol biosynthetic pathway.
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22
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Csáky Z, Garaiová M, Kodedová M, Valachovič M, Sychrová H, Hapala I. Squalene lipotoxicity in a lipid droplet‐less yeast mutant is linked to plasma membrane dysfunction. Yeast 2020; 37:45-62. [DOI: 10.1002/yea.3454] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 12/02/2019] [Accepted: 12/07/2019] [Indexed: 12/13/2022] Open
Affiliation(s)
- Zsófia Csáky
- Department of Membrane Biochemistry Institute of Animal Biochemistry and Genetics, Centre of Biosciences of the Slovak Academy of Sciences Bratislava Slovakia
| | - Martina Garaiová
- Department of Membrane Biochemistry Institute of Animal Biochemistry and Genetics, Centre of Biosciences of the Slovak Academy of Sciences Bratislava Slovakia
| | - Marie Kodedová
- Department of Membrane Transport, Division BIOCEV Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Martin Valachovič
- Department of Membrane Biochemistry Institute of Animal Biochemistry and Genetics, Centre of Biosciences of the Slovak Academy of Sciences Bratislava Slovakia
| | - Hana Sychrová
- Department of Membrane Transport, Division BIOCEV Institute of Physiology of the Czech Academy of Sciences Prague Czech Republic
| | - Ivan Hapala
- Department of Membrane Biochemistry Institute of Animal Biochemistry and Genetics, Centre of Biosciences of the Slovak Academy of Sciences Bratislava Slovakia
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23
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Unusual features of the c-ring of F 1F O ATP synthases. Sci Rep 2019; 9:18547. [PMID: 31811229 PMCID: PMC6897951 DOI: 10.1038/s41598-019-55092-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 11/19/2019] [Indexed: 11/23/2022] Open
Abstract
Membrane integral ATP synthases produce adenosine triphosphate, the universal “energy currency” of most organisms. However, important details of proton driven energy conversion are still unknown. We present the first high-resolution structure (2.3 Å) of the in meso crystallized c-ring of 14 subunits from spinach chloroplasts. The structure reveals molecular mechanisms of intersubunit contacts in the c14-ring, and it shows additional electron densities inside the c-ring which form circles parallel to the membrane plane. Similar densities were found in all known high-resolution structures of c-rings of F1FO ATP synthases from archaea and bacteria to eukaryotes. The densities might originate from isoprenoid quinones (such as coenzyme Q in mitochondria and plastoquinone in chloroplasts) that is consistent with differential UV-Vis spectroscopy of the c-ring samples, unusually large distance between polar/apolar interfaces inside the c-ring and universality among different species. Although additional experiments are required to verify this hypothesis, coenzyme Q and its analogues known as electron carriers of bioenergetic chains may be universal cofactors of ATP synthases, stabilizing c-ring and prevent ion leakage through it.
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24
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Salvador-Castell M, Tourte M, Oger PM. In Search for the Membrane Regulators of Archaea. Int J Mol Sci 2019; 20:E4434. [PMID: 31505830 PMCID: PMC6770870 DOI: 10.3390/ijms20184434] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 09/04/2019] [Accepted: 09/06/2019] [Indexed: 11/23/2022] Open
Abstract
Membrane regulators such as sterols and hopanoids play a major role in the physiological and physicochemical adaptation of the different plasmic membranes in Eukarya and Bacteria. They are key to the functionalization and the spatialization of the membrane, and therefore indispensable for the cell cycle. No archaeon has been found to be able to synthesize sterols or hopanoids to date. They also lack homologs of the genes responsible for the synthesis of these membrane regulators. Due to their divergent membrane lipid composition, the question whether archaea require membrane regulators, and if so, what is their nature, remains open. In this review, we review evidence for the existence of membrane regulators in Archaea, and propose tentative location and biological functions. It is likely that no membrane regulator is shared by all archaea, but that they may use different polyterpenes, such as carotenoids, polyprenols, quinones and apolar polyisoprenoids, in response to specific stressors or physiological needs.
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Affiliation(s)
- Marta Salvador-Castell
- Université de Lyon, CNRS, UMR 5240, F-69621 Villeurbanne, France.
- Université de Lyon, INSA de Lyon, UMR 5240, F-69621 Villeurbanne, France.
| | - Maxime Tourte
- Université de Lyon, CNRS, UMR 5240, F-69621 Villeurbanne, France.
- Université de Lyon, INSA de Lyon, UMR 5240, F-69621 Villeurbanne, France.
| | - Philippe M Oger
- Université de Lyon, CNRS, UMR 5240, F-69621 Villeurbanne, France.
- Université de Lyon, INSA de Lyon, UMR 5240, F-69621 Villeurbanne, France.
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Lipid constituents of model protocell membranes. Emerg Top Life Sci 2019; 3:537-542. [DOI: 10.1042/etls20190021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/19/2019] [Accepted: 07/01/2019] [Indexed: 11/17/2022]
Abstract
Primitive life must have possessed the essential features of modern cellular life, but without highly evolved proteins to perform dynamic functions such as nutrient transport and membrane remodeling. Here, we consider the membrane properties of protocells — minimal cells with hereditary material, capable of growth and division — and how these properties place restrictions on the components of the membrane. For example, the lipids of modern membranes are diacyl amphiphilic molecules containing well-over 20 carbons in total. Without proteins, these membranes are very stable and kinetically trapped. This inertness, combined with the need for enzymes to synthesize them, makes modern diacyl amphiphiles unsuitable candidates for the earliest membranes on Earth. We, therefore, discuss the progress made thus far with single-chained amphiphiles, including fatty acids and mixtures of fatty acids with related molecules, and the membrane-related research that must be undertaken to gain more insight into the origins of cellular life.
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Altinisik Kaya FE, Avci FG, Sayar NA, Kazan D, Sayar AA, Sariyar Akbulut B. What Are the Multi-Omics Mechanisms for Adaptation by Microorganisms to High Alkalinity? A Transcriptomic and Proteomic Study of a Bacillus Strain with Industrial Potential. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2019; 22:717-732. [PMID: 30457468 DOI: 10.1089/omi.2018.0127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Alkaliphilic organisms are among an industrially important class of extremophile microorganisms with the ability to thrive at pH 10-11.5. Microorganisms that exhibit alkaliphilic characteristics are sources of alkali-tolerant enzymes such as proteases, starch degrading enzymes, cellulases, and metabolites such as antibiotics, enzyme inhibitors, siderophores, organic acids, and cholic acid derivatives, which have found various applications in industry for human and environmental health. Yet, multi-omics mechanisms governing adaptation to high alkalinity have been poorly studied. We undertook the present work to understand, as a case study, the alkaliphilic adaptation strategy of the novel microorganism, Bacillus marmarensis DSM 21297, to alkaline conditions using a multi-omics approach that employed transcriptomics and proteomics. As alkalinity increased, bacteria remodeled the peptidoglycan layer by changing peptide moieties along with the peptidoglycan constituents and altered the cell membrane to reduce lipid motility and proton leakiness to adjust intracellular pH. Different transporters also contributed to the maintenance of this pH homeostasis. However, unlike in most well-known alkaliphiles, not only sodium ions but also potassium ions were involved in this process. Interestingly, increased pH has triggered the expression of neither general stress proteins nor gene encoding proteins associated with heat, salt, and nutrient stresses. Only an increase in the expression of oxidative stress related genes was evident. Endospore formation, also a phenomenon closely linked to stress, was unclear. This questioned if high pH was a real stress for B. marmarensis. These new findings, corroborated using the multi-omics approach of the present case study, broaden the knowledge on the mechanisms of alkaliphilic adaptation and might also potentially offer useful departure points for further industrial applications with other microorganisms.
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Affiliation(s)
| | - Fatma Gizem Avci
- Bioengineering Department, Marmara University , Istanbul, Turkey
| | | | - Dilek Kazan
- Bioengineering Department, Marmara University , Istanbul, Turkey
| | - Ahmet Alp Sayar
- Bioengineering Department, Marmara University , Istanbul, Turkey
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The shape of human squalene epoxidase expands the arsenal against cancer. Nat Commun 2019; 10:888. [PMID: 30792392 PMCID: PMC6384927 DOI: 10.1038/s41467-019-08866-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 02/04/2019] [Indexed: 01/31/2023] Open
Abstract
Squalene epoxidase (also known as squalene monooxygenase, EC 1.14.99.7) is a key rate-limiting enzyme in cholesterol biosynthesis. Anil Padyana and colleagues report the long awaited structure of human squalene epoxidase (SQLE). They solved the crystal structure of the catalytic domain of human SQLE alone and in complex with two similar pharmacological inhibitors and elucidate their mechanism of action. SQLE is the target of fungicides and of increasing interest in human health and disease, particularly as a new anti-cancer target. Indeed, in a companion paper, Christopher Mahoney and colleagues performed an inhibitor screen with cancer cell lines and identified SQLE as an unique vulnerability in a subset of neuroendocrine tumours, where SQLE inhibition caused a toxic accumulation of the substrate squalene. The SQLE structure will facilitate the development of improved inhibitors. Here, we comment on these two studies in the wider context of the field and discuss possible future directions.
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Challenges and Adaptations of Life in Alkaline Habitats. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2019; 172:85-133. [DOI: 10.1007/10_2019_97] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Vavourakis CD, Andrei AS, Mehrshad M, Ghai R, Sorokin DY, Muyzer G. A metagenomics roadmap to the uncultured genome diversity in hypersaline soda lake sediments. MICROBIOME 2018; 6:168. [PMID: 30231921 PMCID: PMC6146748 DOI: 10.1186/s40168-018-0548-7] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 09/03/2018] [Indexed: 05/06/2023]
Abstract
BACKGROUND Hypersaline soda lakes are characterized by extreme high soluble carbonate alkalinity. Despite the high pH and salt content, highly diverse microbial communities are known to be present in soda lake brines but the microbiome of soda lake sediments received much less attention of microbiologists. Here, we performed metagenomic sequencing on soda lake sediments to give the first extensive overview of the taxonomic diversity found in these complex, extreme environments and to gain novel physiological insights into the most abundant, uncultured prokaryote lineages. RESULTS We sequenced five metagenomes obtained from four surface sediments of Siberian soda lakes with a pH 10 and a salt content between 70 and 400 g L-1. The recovered 16S rRNA gene sequences were mostly from Bacteria, even in the salt-saturated lakes. Most OTUs were assigned to uncultured families. We reconstructed 871 metagenome-assembled genomes (MAGs) spanning more than 45 phyla and discovered the first extremophilic members of the Candidate Phyla Radiation (CPR). Five new species of CPR were among the most dominant community members. Novel dominant lineages were found within previously well-characterized functional groups involved in carbon, sulfur, and nitrogen cycling. Moreover, key enzymes of the Wood-Ljungdahl pathway were encoded within at least four bacterial phyla never previously associated with this ancient anaerobic pathway for carbon fixation and dissimilation, including the Actinobacteria. CONCLUSIONS Our first sequencing effort of hypersaline soda lake sediment metagenomes led to two important advances. First, we showed the existence and obtained the first genomes of haloalkaliphilic members of the CPR and several hundred other novel prokaryote lineages. The soda lake CPR is a functionally diverse group, but the most abundant organisms in this study are likely fermenters with a possible role in primary carbon degradation. Second, we found evidence for the presence of the Wood-Ljungdahl pathway in many more taxonomic groups than those encompassing known homo-acetogens, sulfate-reducers, and methanogens. Since only few environmental metagenomics studies have targeted sediment microbial communities and never to this extent, we expect that our findings are relevant not only for the understanding of haloalkaline environments but can also be used to set targets for future studies on marine and freshwater sediments.
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Affiliation(s)
- Charlotte D. Vavourakis
- Microbial Systems Ecology, Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, Faculty of Science, University of Amsterdam, Postbus 94248, 1090 GE Amsterdam, the Netherlands
| | - Adrian-Stefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sadkach 7, 370 05 Ceske Budejovice, Czech Republic
| | - Maliheh Mehrshad
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sadkach 7, 370 05 Ceske Budejovice, Czech Republic
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, Na Sadkach 7, 370 05 Ceske Budejovice, Czech Republic
| | - Dimitry Y. Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, 60 let Oktyabrya pr-t, 7, bld. 2, Moscow, Russian Federation 117312
- Environmental Biotechnology, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Gerard Muyzer
- Microbial Systems Ecology, Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, Faculty of Science, University of Amsterdam, Postbus 94248, 1090 GE Amsterdam, the Netherlands
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Suriyakalaa U, Ramachandran R, Usha K, Sankarganesh D, Praveenkumar D, Abinaya S, Tirupathi Pichiah PB, Kamalakkannan S, Achiraman S. Squalene is a potential endocrine modulator in rat: A proof-of-principle study with 3-methylcholanthrene-induced toxicity. Andrologia 2018; 50:e13117. [PMID: 30084500 DOI: 10.1111/and.13117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 06/22/2018] [Accepted: 06/27/2018] [Indexed: 12/29/2022] Open
Abstract
Oestrus urine was proved as a potential endocrine modulator in alleviating the toxicity induced by 3-methylcholanthrene (3-MC) in male rats. We, in this study, aimed to prove the attributing potential of toxicity alleviation to squalene, an oestrus-specific pheromone in rats. A single dose of 3-methylcholanthrene (25 mg/kg BW, i.p.) was administered to male Wistar rats with concurrent exposure to squalene sprayed in bedding material (Group III). Group II rats did receive 3-MC treatment but did not expose to squalene. Group I rats were intact control neither administered 3-MC nor sprayed with squalene. In consequence of 3-MC toxicity, liver and testes weights were increased and the components of blood cells (RBC and WBC count, Hb level) and testosterone concentration were significantly reduced in Group II rats. Moreover, sperm count was reduced and antioxidants (testes and epididymis) were significantly altered. Exposure to squalene in Group III rats comparatively normalised all the variable components towards baseline and reorganised the histological architecture of reproductive tissues that were exacerbated with 3-MC toxicity. This study ultimately proved squalene as a potent molecule in alleviating the toxicity induced by 3-methylcholanthrene.
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Affiliation(s)
- Udhayaraj Suriyakalaa
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, Tamilnadu, India.,Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamilnadu, India
| | - Rajamanickam Ramachandran
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, Tamilnadu, India.,Department of Microbial Biotechnology, Bharathiar University, Coimbatore, Tamilnadu, India
| | - Karuppiah Usha
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, Tamilnadu, India
| | - Devaraj Sankarganesh
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, Tamilnadu, India.,Department of Biotechnology, School of Bio and Chemical Engineering, Kalasalingam Academy of Research & Education, Krishnankoil, Tamilnadu, India
| | - Dharmaraj Praveenkumar
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, Tamilnadu, India
| | - Subramanian Abinaya
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, Tamilnadu, India
| | | | | | - Shanmugam Achiraman
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, Tamilnadu, India
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Jiang Z, Kempinski C, Kumar S, Kinison S, Linscott K, Nybo E, Janze S, Wood C, Chappell J. Agronomic and chemical performance of field-grown tobacco engineered for triterpene and methylated triterpene metabolism. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:1110-1124. [PMID: 29069530 PMCID: PMC5978867 DOI: 10.1111/pbi.12855] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/08/2017] [Indexed: 05/13/2023]
Abstract
Squalene is a linear intermediate to nearly all classes of triterpenes and sterols and is itself highly valued for its use in wide range of industrial applications. Another unique linear triterpene is botryococcene and its methylated derivatives generated by the alga Botryococcus braunii race B, which are progenitors to fossil fuel deposits. Production of these linear triterpenes was previously engineered into transgenic tobacco by introducing the key steps of triterpene metabolism into the particular subcellular compartments. In this study, the agronomic characteristics (height, biomass accumulation, leaf area), the photosynthetic capacity (photosynthesis rate, conductance, internal CO2 levels) and triterpene content of select lines grown under field conditions were evaluated for three consecutive growing seasons. We observed that transgenic lines targeting enzymes to the chloroplasts accumulated 50-150 times more squalene than the lines targeting the enzymes to the cytoplasm, without compromising growth or photosynthesis. We also found that the transgenic lines directing botryococcene metabolism to the chloroplast accumulated 10- to 33-fold greater levels than the lines where the same enzymes were targeted to in the cytoplasm. However, growth of these high botryococcene accumulators was highly compromised, yet their photosynthesis rates remained unaffected. In addition, in the transgenic lines targeting a triterpene methyltransferase (TMT) to the chloroplasts of high squalene accumulators, 55%-65% of total squalene was methylated, whereas in the lines expressing a TMT in the cytoplasm, only 6%-13% of squalene was methylated. The growth of these methylated triterpene-accumulating lines was more compromised than that of nonmethylated squalene lines.
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Affiliation(s)
- Zuodong Jiang
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Chase Kempinski
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Santosh Kumar
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Scott Kinison
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Kristin Linscott
- Molecular and Cellular BiochemistryUniversity of KentuckyLexingtonKYUSA
| | - Eric Nybo
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Sarah Janze
- Department of StatisticsUniversity of KentuckyLexingtonKYUSA
| | - Connie Wood
- Department of StatisticsUniversity of KentuckyLexingtonKYUSA
| | - Joe Chappell
- Plant Biology ProgramUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
- Molecular and Cellular BiochemistryUniversity of KentuckyLexingtonKYUSA
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Hepatic subcellular distribution of squalene changes according to the experimental setting. J Physiol Biochem 2018; 74:531-538. [DOI: 10.1007/s13105-018-0616-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/14/2018] [Indexed: 02/07/2023]
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Ibrahim MF, Abdelaziz N. Assessment of squalene eligibility in bettering some maternal and fetal disorders instigated by gamma irradiation of rats at mid gestation. Int J Radiat Biol 2018; 94:229-237. [PMID: 29310516 DOI: 10.1080/09553002.2018.1425806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE Squalene is an eminent vital part of the synthesis of steroid hormones in the body as well as the first specific intermediate in cholesterol biosynthesis that plays an essential role in normal embryogenesis. The present work was designed to test the maternal and embryonic response to the modulating capacity of squalene (0.4 ml/kg/d), when supplemented to rats from days 1 to 18 of pregnancy, against the damaging consequences induced by maternal subjection to 3 Gy gamma irradiation on day 10 post-conception. MATERIALS AND METHODS The experimental protocol comprised of four different pregnant groups, namely: (1) control, (2) squalene supplemented, (3) irradiated and (4) squalene supplemented + irradiated. RESULTS It has been detected that radiation has increased the maternal blood lactate dehydrogenase (as a marker of tissue injury), cholesterol, triglycerides, estradiol and progesterone and has also provoked the oxidative stress that has been demonstrated by the increased malondialdehyde (MDA) and the decreased glutathione (GSH) and superoxide dismutase (SOD). These maternal changes were associated with high embryonic lethality, growth retardation, severe developmental abnormalities and defective neural tube closure expressed by exencephaly. However, squalene treatment has significantly improved the radiation imposed maternal variations and reduced the embryonic mortality, although it has not been able to attenuate the embryonic neural tube defects. CONCLUSIONS It has been presumed that the maternal mid-gestational irradiation (day 10) has affected the fetal nervous system development with concomitant maternal oxidative stress, hyperlipidemia, and increased progesterone and estradiol levels. Squalene uptake has improved the maternal variations and reduced the embryonic mortality while could not stop or improve the embryonic neural tube defects imposed by radiation at this exact radiation timing.
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Affiliation(s)
- Maha Fawzy Ibrahim
- a Radiation Biology Department , National Centre for Radiation Research and Technology (NCRRT), Atomic Energy Authority , Cairo , Egypt
| | - Nahed Abdelaziz
- a Radiation Biology Department , National Centre for Radiation Research and Technology (NCRRT), Atomic Energy Authority , Cairo , Egypt
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Zhai L, Xie J, Lin Y, Cheng K, Wang L, Yue F, Guo J, Liu J, Yao S. Genome sequencing and heterologous expression of antiporters reveal alkaline response mechanisms of Halomonas alkalicola. Extremophiles 2017; 22:221-231. [PMID: 29270851 DOI: 10.1007/s00792-017-0991-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 12/08/2017] [Indexed: 11/30/2022]
Abstract
Halomonas alkalicola CICC 11012s is an alkaliphilic and halotolerant bacterium isolated from a soap-making tank (pH > 10) from a household-product plant. This strain can propagate at pH 12.5, which is fatal to most bacteria. Genomic analysis revealed that the genome size was 3,511,738 bp and contained 3295 protein-coding genes, including a complete cell wall and plasma membrane lipid biosynthesis pathway. Furthermore, four putative Na+/H+ and K+/H+ antiporter genes, or gene clusters, designated as HaNhaD, HaNhaP, HaMrp and HaPha, were identified within the genome. Heterologous expression of these genes in antiporter-deficient Escherichia coli indicated that HaNhaD, an Na+/H+ antiporter, played a dominant role in Na+ tolerance and pH homeostasis in acidic, neutral and alkaline environments. In addition, HaMrp exhibited Na+ tolerance; however, it functioned mainly in alkaline conditions. Both HaNhaP and HaPha were identified as K+/H+ antiporters that played an important role in high alkalinity and salinity. In summary, genome analysis and heterologous expression experiments demonstrated that a complete set of adaptive strategies have been developed by the double extremophilic strain CICC 11012s in response to alkalinity and salinity. Specifically, four antiporters exhibiting different physiological roles for different situations worked together to support the strain in harsh surroundings.
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Affiliation(s)
- Lei Zhai
- China Center of Industrial Culture Collection (CICC), China National Research Institute of Food and Fermentation Industries, Beijing, 100015, People's Republic of China
| | - Jiuyan Xie
- China Center of Industrial Culture Collection (CICC), China National Research Institute of Food and Fermentation Industries, Beijing, 100015, People's Republic of China
| | - Yafang Lin
- Procter & Gamble Technologies (Beijing) Ltd, Beijing, 101312, People's Republic of China
| | - Kun Cheng
- China Center of Industrial Culture Collection (CICC), China National Research Institute of Food and Fermentation Industries, Beijing, 100015, People's Republic of China
| | - Lijiang Wang
- Procter & Gamble Technologies (Beijing) Ltd, Beijing, 101312, People's Republic of China
| | - Feng Yue
- Procter & Gamble Technologies (Beijing) Ltd, Beijing, 101312, People's Republic of China
| | - Jingyan Guo
- Procter & Gamble Technologies (Beijing) Ltd, Beijing, 101312, People's Republic of China
| | - Jiquan Liu
- Procter & Gamble International Operations SA Singapore Branch, 70 Biopolis Street, Singapore, 138547, Singapore.
| | - Su Yao
- China Center of Industrial Culture Collection (CICC), China National Research Institute of Food and Fermentation Industries, Beijing, 100015, People's Republic of China.
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Palanco ME, Skovgaard N, Hansen JS, Berg-Sørensen K, Hélix-Nielsen C. Tuning biomimetic membrane barrier properties by hydrocarbon, cholesterol and polymeric additives. BIOINSPIRATION & BIOMIMETICS 2017; 13:016005. [PMID: 29019793 DOI: 10.1088/1748-3190/aa92be] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The barrier properties of cellular membranes are increasingly attracting attention as a source of inspiration for designing biomimetic membranes. The broad range of potential technological applications makes the use of lipid and lately also polymeric materials a popular choice for constructing biomimetic membranes, where the barrier properties can be controlled by the composition of the membrane constituent elements. Here we investigate the membrane properties reported by the light-induced proton pumping activity of bacteriorhodopsin (bR) reconstituted in three vesicle systems of different membrane composition. Specifically we quantify how the resulting proton influx and efflux rates are influenced by the membrane composition using a variety of membrane modulators. We demonstrate that by adding hydrocarbons to vesicles with reconstituted bR formed from asolectin lipids the resulting transmembrane proton fluxes changes proportional to the carbon chain length when compared against control. We observe a similar proportionality in single-component 1,2-Dioleoyl-sn-glycero-3-phosphocholine model membranes when using cholesterol. Lastly we investigate the effects of adding the amphiphilic di-block co-polymer polybutadiene-polyethyleneoxide (PB12-PEO10) to phospholipid membranes formed from 1,2-Dioleoyl-sn-glycero-3-phosphocholine, 1,2-Dioleoyl-sn-glycero-3-phosphatidylethanolamine, and 1,2-Dioleoyl-sn-glycero-3-phosphatidylserine. The proton pumping activity of bR (measured as a change in extra-vesicular pH) in mixed lipid/PB12-PEO10 lipid systems is up to six-fold higher compared to that observed for bR containing vesicles made from PB12-PEO10 alone. Interestingly, bR inserts with apparent opposite orientation in pure PB12-PEO10 vesicles as compared to pure lipid vesicles. Addition of equimolar amounts of lipids to PB12-PEO10 results in bR orientation similar to that observed for pure lipids. In conclusion our results show how the barrier properties of the membranes can be controlled by the composition of the membrane. In particular the use of mixed lipid-polymer systems may pave the way for constructing biomimetic membranes tailored for optimal properties in various applications including drug delivery systems, biosensors and energy conservation technology.
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Affiliation(s)
- Marta Espina Palanco
- Department of Physics, Technical University of Denmark (DTU), 2800 Kgs. Lyngby, Denmark. These authors contributed equally to this work
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Siliakus MF, van der Oost J, Kengen SWM. Adaptations of archaeal and bacterial membranes to variations in temperature, pH and pressure. Extremophiles 2017; 21:651-670. [PMID: 28508135 PMCID: PMC5487899 DOI: 10.1007/s00792-017-0939-x] [Citation(s) in RCA: 197] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 04/29/2017] [Indexed: 12/30/2022]
Abstract
The cytoplasmic membrane of a prokaryotic cell consists of a lipid bilayer or a monolayer that shields the cellular content from the environment. In addition, the membrane contains proteins that are responsible for transport of proteins and metabolites as well as for signalling and energy transduction. Maintenance of the functionality of the membrane during changing environmental conditions relies on the cell's potential to rapidly adjust the lipid composition of its membrane. Despite the fundamental chemical differences between bacterial ester lipids and archaeal ether lipids, both types are functional under a wide range of environmental conditions. We here provide an overview of archaeal and bacterial strategies of changing the lipid compositions of their membranes. Some molecular adjustments are unique for archaea or bacteria, whereas others are shared between the two domains. Strikingly, shared adjustments were predominantly observed near the growth boundaries of bacteria. Here, we demonstrate that the presence of membrane spanning ether-lipids and methyl branches shows a striking relationship with the growth boundaries of archaea and bacteria.
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Affiliation(s)
- Melvin F Siliakus
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Servé W M Kengen
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
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Seçmeler Ö, Güçlü Üstündağ Ö. Behavior of lipophilic bioactives during olive oil processing. EUR J LIPID SCI TECH 2017. [DOI: 10.1002/ejlt.201600404] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Özge Seçmeler
- Faculty of Engineering; Department of Food Engineering; Yeditepe University; Istanbul Turkey
| | - Özlem Güçlü Üstündağ
- Faculty of Engineering; Department of Food Engineering; Yeditepe University; Istanbul Turkey
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Schroeter A, Stahlberg S, Školová B, Sonnenberger S, Eichner A, Huster D, Vávrová K, Hauß T, Dobner B, Neubert RHH, Vogel A. Phase separation in ceramide[NP] containing lipid model membranes: neutron diffraction and solid-state NMR. SOFT MATTER 2017; 13:2107-2119. [PMID: 28225091 DOI: 10.1039/c6sm02356h] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The stratum corneum is the outermost layer of the skin and protects the organism against external influences as well as water loss. It consists of corneocytes embedded in a mixture of ceramides, fatty acids, and cholesterol in a molar ratio of roughly 1 : 1 : 1. The unique structural and compositional arrangement of these stratum corneum lipids is responsible for the skin barrier properties. Many studies investigated the organization of these barrier lipids and, in particular, the exact conformation of ceramides. However, so far no consensus has been reached. In this study, we investigate a model system comprised of N-(non-hydroxy-tetracosanoyl)-phytosphingosine/cholesterol/tetracosanoic acid (CER[NP]-C24/CHOL/TA) at a 1 : 1 : 1 molar ratio using neutron diffraction and 2H solid-state NMR spectroscopy at temperatures from 25 °C to 80 °C. Deuterated variants of all three lipid components of the model system were used to enable their separate investigation in the NMR spectra and quantification of the amount of molecules in each phase. Neutron scattering experiments show the coexistence of two lipid phases at low temperatures with repeat spacings of 54.2 Å and 43.0 Å at a physiological skin temperature of 32 °C. They appear to be indistinguishable in the 2H NMR spectra as both phases are crystalline and ceramide molecules do not rotate around their long axis on a microsecond timescale. The evolution of these phases upon heating is followed and with increasing temperature fluid and even isotropically mobile molecules are observed. A model of the organization of the lamellar phases is proposed in which the thicker phase consists of CER[NP]-C24 in a hairpin conformation mixed with CHOL and TA, while the phase with a repeat spacing of 43.0 Å contains CER[NP]-C24 in a V-shape conformation.
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Affiliation(s)
- Annett Schroeter
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Sören Stahlberg
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany.
| | - Barbora Školová
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany. and Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203, 50005 Hradec Králové, Czech Republic
| | - Stefan Sonnenberger
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Adina Eichner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany.
| | - Kateřina Vávrová
- Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203, 50005 Hradec Králové, Czech Republic
| | - Thomas Hauß
- Institute of Soft Matter and Functional Materials, Helmholtz-Zentrum für Materialien und Energie, Berlin, Germany
| | - Bodo Dobner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Reinhard H H Neubert
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany and Institute of Applied Dermatopharmacy at the Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Alexander Vogel
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany.
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Berben T, Overmars L, Sorokin DY, Muyzer G. Comparative Genome Analysis of Three Thiocyanate Oxidizing Thioalkalivibrio Species Isolated from Soda Lakes. Front Microbiol 2017; 8:254. [PMID: 28293216 PMCID: PMC5328954 DOI: 10.3389/fmicb.2017.00254] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 02/07/2017] [Indexed: 12/21/2022] Open
Abstract
Thiocyanate is a C1 compound containing carbon, nitrogen, and sulfur. It is a (by)product in a number of natural and industrial processes. Because thiocyanate is toxic to many organisms, including humans, its removal from industrial waste streams is an important problem. Although a number of bacteria can use thiocyanate as a nitrogen source, only a few can use it as an electron donor. There are two distinct pathways to use thiocyanate: (i) the “carbonyl sulfide pathway,” which has been extensively studied, and (ii) the “cyanate pathway,” whose key enzyme, thiocyanate dehydrogenase, was recently purified and studied. Three species of Thioalkalivibrio, a group of haloalkaliphilic sulfur-oxidizing bacteria isolated from soda lakes, have been described as thiocyanate oxidizers: (i) Thioalkalivibrio paradoxus (“cyanate pathway”), (ii) Thioalkalivibrio thiocyanoxidans (“cyanate pathway”) and (iii) Thioalkalivibrio thiocyanodenitrificans (“carbonyl sulfide pathway”). In this study we provide a comparative genome analysis of these described thiocyanate oxidizers, with genomes ranging in size from 2.5 to 3.8 million base pairs. While focusing on thiocyanate degradation, we also analyzed the differences in sulfur, carbon, and nitrogen metabolism. We found that the thiocyanate dehydrogenase gene is present in 10 different Thioalkalivibrio strains, in two distinct genomic contexts/genotypes. The first genotype is defined by having genes for flavocytochrome c sulfide dehydrogenase upstream from the thiocyanate dehydrogenase operon (present in two strains including the type strain of Tv. paradoxus), whereas in the second genotype these genes are located downstream, together with two additional genes of unknown function (present in eight strains, including the type strains of Tv. thiocyanoxidans). Additionally, we found differences in the presence/absence of genes for various sulfur oxidation pathways, such as sulfide:quinone oxidoreductase, dissimilatory sulfite reductase, and sulfite dehydrogenase. One strain (Tv. thiocyanodenitrificans) lacks genes encoding a carbon concentrating mechanism and none of the investigated genomes were shown to contain known bicarbonate transporters. This study gives insight into the genomic variation of thiocyanate oxidizing bacteria and may lead to improvements in the application of these organisms in the bioremediation of industrial waste streams.
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Affiliation(s)
- Tom Berben
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, Netherlands
| | - Lex Overmars
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, Netherlands
| | - Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of SciencesMoscow, Russia; Department of Biotechnology, Delft University of TechnologyDelft, Netherlands
| | - Gerard Muyzer
- Microbial Systems Ecology, Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam Amsterdam, Netherlands
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40
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Squalene Extraction by Supercritical Fluids from Traditionally Puffed Amaranthus hypochondriacus Seeds. J FOOD QUALITY 2017. [DOI: 10.1155/2017/6879712] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Extraction of squalene, a potent natural antioxidant, from puffed A. hypochondriacus seeds was performed by supercritical fluid extraction (SCFE); besides, to have a blank for comparison, extraction was performed also by Soxhlet method using organic solvents (hexane). Chemical proximal composition and seed morphology were determined in raw, puffed, and SCFE-extracted seeds. Extracts were obtained with a 500 mL capacity commercial supercritical extractor and performed between 10 and 30 MPa at 313, 323, and 333 K under constant CO2 flow of 0.18 kg CO2/h during 8 h. The squalene content was determined and the fatty acids present in the extracts were identified by GC-MS. The extract obtained by SCFE from puffed amaranth seeds reached 460 ± 28.1 g/kg squalene in oily extract at 313 K/20 MPa.
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Kellermann MY, Yoshinaga MY, Valentine RC, Wörmer L, Valentine DL. Important roles for membrane lipids in haloarchaeal bioenergetics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2940-2956. [PMID: 27565574 DOI: 10.1016/j.bbamem.2016.08.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 08/11/2016] [Accepted: 08/19/2016] [Indexed: 10/21/2022]
Abstract
Recent advances in lipidomic analysis in combination with various physiological experiments set the stage for deciphering the structure-function of haloarchaeal membrane lipids. Here we focused primarily on changes in lipid composition of Haloferax volcanii, but also performed a comparative analysis with four other haloarchaeal species (Halobacterium salinarum, Halorubrum lacusprofundi, Halorubrum sodomense and Haloplanus natans) all representing distinctive cell morphologies and behaviors (i.e., rod shape vs. pleomorphic behavior). Common to all five haloarchaea, our data reveal an extraordinary high level of menaquinone, reaching up to 72% of the total lipids. This ubiquity suggests that menaquinones may function beyond their ordinary role as electron and proton transporter, acting simultaneously as ion permeability barriers and as powerful shield against oxidative stress. In addition, we aimed at understanding the role of cations interacting with the characteristic negatively charged surface of haloarchaeal membranes. We propose for instance that by bridging the negative charges of adjacent anionic phospholipids, Mg2+ acts as surrogate for cardiolipin, a molecule that is known to control curvature stress of membranes. This study further provides a bioenergetic perspective as to how haloarchaea evolved following oxygenation of Earth's atmosphere. The success of the aerobic lifestyle of haloarchaea includes multiple membrane-based strategies that successfully balance the need for a robust bilayer structure with the need for high rates of electron transport - collectively representing the molecular basis to inhabit hypersaline water bodies around the planet.
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Affiliation(s)
- Matthias Y Kellermann
- Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
| | - Marcos Y Yoshinaga
- MARUM Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Leobener Strasse, D-28359 Bremen, Germany
| | | | - Lars Wörmer
- MARUM Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Leobener Strasse, D-28359 Bremen, Germany
| | - David L Valentine
- Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
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From hopanoids to cholesterol: Molecular clocks of pentameric ligand-gated ion channels. Prog Lipid Res 2016; 63:1-13. [DOI: 10.1016/j.plipres.2016.03.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 03/22/2016] [Accepted: 03/24/2016] [Indexed: 11/21/2022]
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Quirk A, Lardner MJ, Tun Z, Burgess IJ. Surface-Enhanced Infrared Spectroscopy and Neutron Reflectivity Studies of Ubiquinone in Hybrid Bilayer Membranes under Potential Control. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:2225-2235. [PMID: 26867110 DOI: 10.1021/acs.langmuir.5b04263] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Surface-enhanced infrared adsorption spectroscopy (SEIRAS) and neutron reflectometry (NR) were employed to characterize ubiquinone (UQ) containing hybrid bilayer membranes. The biomimetic membrane was prepared by fusing phospholipid vesicles on a hydrophobic octadecanethiol monolayer self-assembled on a thin gold film. Using SEIRAS, the assembly of the membrane is monitored in situ. The presence of ubiquinone is verified by the characteristic carbonyl peaks from the quinone ester. A well-ordered distal lipid leaflet results from fusion of vesicles with and without the addition of ubiquinone. With applied potential, the hybrid bilayer membrane in the absence of UQ behaves in the same way as previously reported solid supported phospholipid membranes. When ubiquinone is incorporated in the membrane, electric field induced changes in the distal leaflet are suppressed. Changes in the infrared vibrations of the ubiquinone due to applied potential indicate the head groups are located in both polar and nonpolar environments. The spectroscopic data reveal that the isoprenoid unit of the ubiquinone is likely lying in the midplane of the lipid bilayer while the head has some freedom to move within the hydrophobic core. The SEIRAS experiments show redox behavior of UQ incorporated in a model lipid membrane that are otherwise inaccessible with traditional electrochemistry techniques.
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Affiliation(s)
- Amanda Quirk
- Department of Chemistry, University of Saskatchewan , Saskatoon, SK, Canada S7N 5C9
| | - Michael J Lardner
- Department of Chemistry, University of Saskatchewan , Saskatoon, SK, Canada S7N 5C9
| | - Zin Tun
- Canadian Neutron Beam Centre, Chalk River Laboratories , Chalk River, ON, Canada K0J 1J0
| | - Ian J Burgess
- Department of Chemistry, University of Saskatchewan , Saskatoon, SK, Canada S7N 5C9
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44
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Milianta PJ, Muzzio M, Denver J, Cawley G, Lee S. Water Permeability across Symmetric and Asymmetric Droplet Interface Bilayers: Interaction of Cholesterol Sulfate with DPhPC. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12187-12196. [PMID: 26492572 DOI: 10.1021/acs.langmuir.5b02748] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cellular membranes employ a variety of strategies for controlling the flow of small molecules into the cytoplasmic space, including incorporation of sterols for modulation of permeability and maintenance of lipid asymmetry to provide both sides of the membrane with differing biophysical properties. The specific case of cholesterol asymmetry, especially, is known to have profound effects in neurological cellular systems. Synthetic membrane models that can readily determine valuable physical parameters, such as water transport rates, for sterol-containing membranes of defined lipid composition remain in demand. We report the use of the droplet interface bilayer (DIB), composed of adherent aqueous droplets surrounded by a lipid monolayer and immersed in a hydrophobic medium, for measurement of water permeability across the membrane, with rapid visualization and ease of experimental setup. We studied droplet bilayer membranes composed of the prototypical synthetic membrane lipid (i.e., the archaeal lipid DPhPC) as well as of symmetric and asymmetric DIBs formed by DPhPC and sodium cholesterol sulfate (S-Chol). The presence of S-Chol in DPhPC in symmetric DIB reduced the passive water permeability rate (P(f)) at all concentrations and increased the activation energy (E(a)) to 17-18 kcal/mol. When only one side of the DIB contains S-Chol (asymmetric DIB), an E(a) of 14-15 kcal/mol was obtained, a value intermediate that of pure lipid and symmetrical DIB containing lipid and S-Chol. Our data are consistent with a capability for regulation of water transport by one leaflet independent of the other. The engineering of our various systems is believed to have implications for garnering detailed knowledge regarding the transport of small moieties across bilayers in a wide variety of lipid systems.
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Affiliation(s)
- Peter J Milianta
- Department of Chemistry, Iona College , 715 North Avenue, New Rochelle, New York 10801, United States
| | - Michelle Muzzio
- Department of Chemistry, Iona College , 715 North Avenue, New Rochelle, New York 10801, United States
| | - Jacqueline Denver
- Department of Chemistry, Iona College , 715 North Avenue, New Rochelle, New York 10801, United States
| | - Geoffrey Cawley
- Department of Chemistry, Iona College , 715 North Avenue, New Rochelle, New York 10801, United States
| | - Sunghee Lee
- Department of Chemistry, Iona College , 715 North Avenue, New Rochelle, New York 10801, United States
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45
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Malmierca MG, McCormick SP, Cardoza RE, Monte E, Alexander NJ, Gutiérrez S. Trichodiene Production in a Trichoderma harzianum erg1-Silenced Strain Provides Evidence of the Importance of the Sterol Biosynthetic Pathway in Inducing Plant Defense-Related Gene Expression. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:1181-1197. [PMID: 26168138 DOI: 10.1094/mpmi-06-15-0127-r] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Trichoderma species are often used as biocontrol agents against plant-pathogenic fungi. A complex molecular interaction occurs among the biocontrol agent, the antagonistic fungus, and the plant. Terpenes and sterols produced by the biocontrol fungus have been found to affect gene expression in both the antagonistic fungus and the plant. The terpene trichodiene (TD) elicits the expression of genes related to tomato defense and to Botrytis virulence. We show here that TD itself is able to induce the expression of Botrytis genes involved in the synthesis of botrydial (BOT) and also induces terpene gene expression in Trichoderma spp. The terpene ergosterol, in addition to its role as a structural component of the fungal cell membranes, acts as an elicitor of defense response in plants. In the present work, using a transformant of T. harzianum, which is silenced in the erg1 gene and accumulates high levels of squalene, we show that this ergosterol precursor also acts as an important elicitor molecule of tomato defense-related genes and induces Botrytis genes involved in BOT biosynthesis, in both cases, in a concentration-dependent manner. Our data emphasize the importance of a balance of squalene and ergosterol in fungal interactions as well as in the biocontrol activity of Trichoderma spp.
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Affiliation(s)
- M G Malmierca
- 1 Area of Microbiology, Universitary School of Agricultural Engineers, University of León, Campus de Ponferrada. Avda, Astorga s/n, 24400 Ponferrada, Spain
| | - S P McCormick
- 2 Bacterial Foodborne Pathogen and Mycology Unit, USDA/ARS, National Center for Agricultural Utilization Research, Peoria, IL 61604-3902, U.S.A
| | - R E Cardoza
- 1 Area of Microbiology, Universitary School of Agricultural Engineers, University of León, Campus de Ponferrada. Avda, Astorga s/n, 24400 Ponferrada, Spain
| | - E Monte
- 3 Spanish-Portuguese Centre of Agricultural Research (CIALE), Department of Microbiology and Genetics, University of Salamanca, 37185 Salamanca, Spain
| | - N J Alexander
- 2 Bacterial Foodborne Pathogen and Mycology Unit, USDA/ARS, National Center for Agricultural Utilization Research, Peoria, IL 61604-3902, U.S.A
| | - S Gutiérrez
- 1 Area of Microbiology, Universitary School of Agricultural Engineers, University of León, Campus de Ponferrada. Avda, Astorga s/n, 24400 Ponferrada, Spain
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Cario A, Grossi V, Schaeffer P, Oger PM. Membrane homeoviscous adaptation in the piezo-hyperthermophilic archaeon Thermococcus barophilus. Front Microbiol 2015; 6:1152. [PMID: 26539180 PMCID: PMC4612709 DOI: 10.3389/fmicb.2015.01152] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/05/2015] [Indexed: 12/22/2022] Open
Abstract
The archaeon Thermococcus barophilus, one of the most extreme members of hyperthermophilic piezophiles known thus far, is able to grow at temperatures up to 103°C and pressures up to 80 MPa. We analyzed the membrane lipids of T. barophilus by high performance liquid chromatography–mass spectrometry as a function of pressure and temperature. In contrast to previous reports, we show that under optimal growth conditions (40 MPa, 85°C) the membrane spanning tetraether lipid GDGT-0 (sometimes called caldarchaeol) is a major membrane lipid of T. barophilus together with archaeol. Increasing pressure and decreasing temperature lead to an increase of the proportion of archaeol. Reversely, a higher proportion of GDGT-0 is observed under low pressure and high temperature conditions. Noticeably, pressure and temperature fluctuations also impact the level of unsaturation of apolar lipids having an irregular polyisoprenoid carbon skeleton (unsaturated lycopane derivatives), suggesting a structural role for these neutral lipids in the membrane of T. barophilus. Whether these apolar lipids insert in the membrane or not remains to be addressed. However, our results raise questions about the structure of the membrane in this archaeon and other Archaea harboring a mixture of di- and tetraether lipids.
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Affiliation(s)
- Anaïs Cario
- CNRS, Laboratoire de Géologie de Lyon, Ecole Normale Supérieure de Lyon, UMR 5276, Université Claude Bernard Lyon 1 Lyon, France
| | - Vincent Grossi
- CNRS, Laboratoire de Géologie de Lyon, Ecole Normale Supérieure de Lyon, UMR 5276, Université Claude Bernard Lyon 1 Lyon, France
| | - Philippe Schaeffer
- CNRS, Laboratoire de Biogéochimie Moléculaire, Institut de Chimie de Strasbourg, Ecole de Chimie, Polymères et Matériaux, UMR 7177, Université de Strasbourg Strasbourg, France
| | - Philippe M Oger
- CNRS, Laboratoire de Géologie de Lyon, Ecole Normale Supérieure de Lyon, UMR 5276, Université Claude Bernard Lyon 1 Lyon, France
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47
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Structural insights on cholesterol endosynthesis: Binding of squalene and 2,3-oxidosqualene to supernatant protein factor. J Struct Biol 2015; 190:261-70. [DOI: 10.1016/j.jsb.2015.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 05/08/2015] [Accepted: 05/11/2015] [Indexed: 11/24/2022]
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48
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Banciu HL, Muntyan MS. Adaptive strategies in the double-extremophilic prokaryotes inhabiting soda lakes. Curr Opin Microbiol 2015; 25:73-9. [PMID: 26025020 DOI: 10.1016/j.mib.2015.05.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 04/27/2015] [Accepted: 05/01/2015] [Indexed: 10/23/2022]
Abstract
Haloalkaliphiles are double extremophilic organisms thriving both at high salinity and alkaline pH. Although numerous haloalkaliphilic representatives have been identified among Archaea and Bacteria over the past 15 years, the adaptations underlying their prosperity at haloalkaline conditions are scarcely known. A multi-level adaptive strategy was proposed to occur in haloalkaliphilic organisms isolated from saline alkaline and soda environments including adjustments in the cell wall structure, plasma membrane lipid composition, membrane transport systems, bioenergetics, and osmoregulation. Isolation of chemolithoautotrophic sulfur-oxidizing γ-Proteobacteria from soda lakes allowed the elucidation of the structural and physiological differences between haloalkaliphilic (prefer NaCl) and natronophilic (prefer NaHCO3/Na2CO3, i.e. soda) microbes.
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Affiliation(s)
- Horia Leonard Banciu
- Institute for Interdisciplinary Research in Bio-Nano-Sciences, Molecular Biology Center, Babeş-Bolyai University, 400271 Cluj-Napoca, Romania; Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 400006 Cluj-Napoca, Romania.
| | - Maria S Muntyan
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow 119991, Russia
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49
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Marquardt D, Kučerka N, Katsaras J, Harroun TA. α-Tocopherol's Location in Membranes Is Not Affected by Their Composition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:4464-4472. [PMID: 25317847 DOI: 10.1021/la502605c] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
To this day, α-tocopherol's (aToc) role in humans is not well known. In previous studies, we have tried to connect aToc's biological function with its location in a lipid bilayer. In the present study, we have determined, by means of small-angle neutron diffraction, that not only is aToc's hydroxyl group located high in the membrane but its tail also resides far from the center of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayers. In addition, we located aToc's hydroxyl group above the lipid backbone in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE), 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS), and sphingomyelin bilayers, suggesting that aToc's location near the lipid-water interface may be a universal property of vitamin E. In light of these data, how aToc efficiently terminates lipid hydroperoxy radicals at the membrane center remains an open question.
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Affiliation(s)
- Drew Marquardt
- †Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - Norbert Kučerka
- ‡National Research Council, Canadian Neutron Beam Centre, Chalk River, Ontario K0J 1J0, Canada
- §Department of Physical Chemistry of Drugs, Comenius University, 832 32 Bratislava, Slovakia
- ∥Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna - Moscow Region, Russia
| | - John Katsaras
- †Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada
- ⊥Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, United States
- #Joint Institute for Neutron Sciences, Oak Ridge, Tennessee37831-6453, United States
- ∇Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Thad A Harroun
- †Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada
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50
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Sorokin DY, Berben T, Melton ED, Overmars L, Vavourakis CD, Muyzer G. Microbial diversity and biogeochemical cycling in soda lakes. Extremophiles 2014; 18:791-809. [PMID: 25156418 PMCID: PMC4158274 DOI: 10.1007/s00792-014-0670-9] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 06/26/2014] [Indexed: 01/26/2023]
Abstract
Soda lakes contain high concentrations of sodium carbonates resulting in a stable elevated pH, which provide a unique habitat to a rich diversity of haloalkaliphilic bacteria and archaea. Both cultivation-dependent and -independent methods have aided the identification of key processes and genes in the microbially mediated carbon, nitrogen, and sulfur biogeochemical cycles in soda lakes. In order to survive in this extreme environment, haloalkaliphiles have developed various bioenergetic and structural adaptations to maintain pH homeostasis and intracellular osmotic pressure. The cultivation of a handful of strains has led to the isolation of a number of extremozymes, which allow the cell to perform enzymatic reactions at these extreme conditions. These enzymes potentially contribute to biotechnological applications. In addition, microbial species active in the sulfur cycle can be used for sulfur remediation purposes. Future research should combine both innovative culture methods and state-of-the-art 'meta-omic' techniques to gain a comprehensive understanding of the microbes that flourish in these extreme environments and the processes they mediate. Coupling the biogeochemical C, N, and S cycles and identifying where each process takes place on a spatial and temporal scale could unravel the interspecies relationships and thereby reveal more about the ecosystem dynamics of these enigmatic extreme environments.
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Affiliation(s)
- Dimitry Y. Sorokin
- Winogradsky Institute of Microbiology, RAS, Moscow, Russia
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Tom Berben
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Emily Denise Melton
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Lex Overmars
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Charlotte D. Vavourakis
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Gerard Muyzer
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
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