1
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Wunderling K, Zurkovic J, Zink F, Kuerschner L, Thiele C. Triglyceride cycling enables modification of stored fatty acids. Nat Metab 2023; 5:699-709. [PMID: 37012495 PMCID: PMC10132980 DOI: 10.1038/s42255-023-00769-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 02/27/2023] [Indexed: 04/05/2023]
Abstract
Triglyceride cycling is the process of continuous degradation and re-synthesis of triglyceride in cellular stores. We show in 3T3-L1 adipocytes that triglycerides are subject to rapid turnover and re-arrangement of fatty acids with an estimated half-life of 2-4 h. We develop a tracing technology that can simultaneously and quantitatively follow the metabolism of multiple fatty acids to study the triglyceride futile substrate cycle directly and with molecular species resolution. Our approach is based on alkyne fatty acid tracers and mass spectrometry. The triglyceride cycling is connected to modification of released fatty acids by elongation and desaturation. Through cycling and modification, saturated fatty acids are slowly converted to monounsaturated fatty acids, and linoleic acid to arachidonic acid. We conclude that triglyceride cycling renders stored fatty acids accessible for metabolic alteration. The overall process facilitates cellular adjustments to the stored fatty acid pool to meet changing needs of the cell.
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Affiliation(s)
- Klaus Wunderling
- LIMES Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Jelena Zurkovic
- LIMES Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Fabian Zink
- LIMES Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Lars Kuerschner
- LIMES Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Christoph Thiele
- LIMES Life and Medical Sciences Institute, University of Bonn, Bonn, Germany.
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2
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Levental I, Lyman E. Regulation of membrane protein structure and function by their lipid nano-environment. Nat Rev Mol Cell Biol 2023; 24:107-122. [PMID: 36056103 PMCID: PMC9892264 DOI: 10.1038/s41580-022-00524-4] [Citation(s) in RCA: 144] [Impact Index Per Article: 144.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2022] [Indexed: 02/04/2023]
Abstract
Transmembrane proteins comprise ~30% of the mammalian proteome, mediating metabolism, signalling, transport and many other functions required for cellular life. The microenvironment of integral membrane proteins (IMPs) is intrinsically different from that of cytoplasmic proteins, with IMPs solvated by a compositionally and biophysically complex lipid matrix. These solvating lipids affect protein structure and function in a variety of ways, from stereospecific, high-affinity protein-lipid interactions to modulation by bulk membrane properties. Specific examples of functional modulation of IMPs by their solvating membranes have been reported for various transporters, channels and signal receptors; however, generalizable mechanistic principles governing IMP regulation by lipid environments are neither widely appreciated nor completely understood. Here, we review recent insights into the inter-relationships between complex lipidomes of mammalian membranes, the membrane physicochemical properties resulting from such lipid collectives, and the regulation of IMPs by either or both. The recent proliferation of high-resolution methods to study such lipid-protein interactions has led to generalizable insights, which we synthesize into a general framework termed the 'functional paralipidome' to understand the mutual regulation between membrane proteins and their surrounding lipid microenvironments.
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Affiliation(s)
- Ilya Levental
- Department of Molecular Physiology and Biological Physics, Center for Molecular and Cell Physiology, University of Virginia, Charlottesville, VA, USA.
| | - Ed Lyman
- Department of Physics and Astronomy, Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA.
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3
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Dixit A, Jose GP, Shanbhag C, Tagad N, Kalia J. Metabolic Labeling-Based Chemoproteomics Establishes Choline Metabolites as Protein Function Modulators. ACS Chem Biol 2022; 17:2272-2283. [PMID: 35802552 DOI: 10.1021/acschembio.2c00400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Choline is an essential nutrient for mammalian cells. Our understanding of the cellular functions of choline and its metabolites, independent of their roles as choline lipid metabolism intermediates, remains limited. In addition to fundamental cellular physiology, this knowledge has implications for cancer biology because elevated choline metabolite levels are a hallmark of cancer. Here, we establish a mammalian choline metabolite-interacting proteome by utilizing a photocrosslinkable choline probe. To design this probe, we performed metabolic labeling experiments with structurally diverse choline analogues that resulted in the serendipitous discovery of a choline lipid headgroup remodeling mechanism involving sequential dealkylation and methylation steps. We demonstrate that phosphocholine inhibits the binding of one of the proteins identified, the attractive anticancer target p32, to its endogenous ligands and to the promising p32-targeting anticancer agent, Lyp-1. Our results reveal that choline metabolites play vital roles in cellular physiology by serving as modulators of protein function.
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Affiliation(s)
- Aditi Dixit
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India.,Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Gregor P Jose
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| | - Chitra Shanbhag
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| | - Nitin Tagad
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| | - Jeet Kalia
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India.,Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India.,Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India.,Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
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4
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Yang PP, Li YJ, Cao Y, Zhang L, Wang JQ, Lai Z, Zhang K, Shorty D, Xiao W, Cao H, Wang L, Wang H, Liu R, Lam KS. Rapid discovery of self-assembling peptides with one-bead one-compound peptide library. Nat Commun 2021; 12:4494. [PMID: 34301935 PMCID: PMC8302598 DOI: 10.1038/s41467-021-24597-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 04/28/2021] [Indexed: 12/02/2022] Open
Abstract
Self-assembling peptides have shown tremendous potential in the fields of material sciences, nanoscience, and medicine. Because of the vast combinatorial space of even short peptides, identification of self-assembling sequences remains a challenge. Herein, we develop an experimental method to rapidly screen a huge array of peptide sequences for self-assembling property, using the one-bead one-compound (OBOC) combinatorial library method. In this approach, peptides on beads are N-terminally capped with nitro-1,2,3-benzoxadiazole, a hydrophobicity-sensitive fluorescence molecule. Beads displaying self-assembling peptides would fluoresce under aqueous environment. Using this approach, we identify eight pentapeptides, all of which are able to self-assemble into nanoparticles or nanofibers. Some of them are able to interact with and are taken up efficiently by HeLa cells. Intracellular distribution varied among these non-toxic peptidic nanoparticles. This simple screening strategy has enabled rapid identification of self-assembling peptides suitable for the development of nanostructures for various biomedical and material applications. Self-assembling peptides have a range of potential applications but developing self-assembling sequences can be challenging. Here, the authors report on a one-bead one-compound combinatorial library where fluorescence is used to detect the potential for self-assembly and identified candidates are evaluated.
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Affiliation(s)
- Pei-Pei Yang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST) No. 11 Beiyitiao, Zhongguancun, Beijing, China
| | - Yi-Jing Li
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST) No. 11 Beiyitiao, Zhongguancun, Beijing, China.,Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China
| | - Yan Cao
- Institute for Advanced Study, Shenzhen University, Guangdong, China
| | - Lu Zhang
- Department of Biochemistry and Molecular Medicine, UC Davis NCI-designated Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA
| | - Jia-Qi Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST) No. 11 Beiyitiao, Zhongguancun, Beijing, China
| | - Ziwei Lai
- Institute for Advanced Study, Shenzhen University, Guangdong, China
| | - Kuo Zhang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST) No. 11 Beiyitiao, Zhongguancun, Beijing, China.,Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China
| | - Diedra Shorty
- Department of Biochemistry and Molecular Medicine, UC Davis NCI-designated Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA
| | - Wenwu Xiao
- Department of Biochemistry and Molecular Medicine, UC Davis NCI-designated Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA
| | - Hui Cao
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China
| | - Lei Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST) No. 11 Beiyitiao, Zhongguancun, Beijing, China.
| | - Hao Wang
- CAS Center for Excellence in Nanoscience, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology (NCNST) No. 11 Beiyitiao, Zhongguancun, Beijing, China. .,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China.
| | - Ruiwu Liu
- Department of Biochemistry and Molecular Medicine, UC Davis NCI-designated Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA.
| | - Kit S Lam
- Department of Biochemistry and Molecular Medicine, UC Davis NCI-designated Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA. .,Division of Hematology and Oncology, Department of Internal Medicine, School of Medicine, University of California Davis, Sacramento, CA, USA.
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5
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Chen T, Yavuz A, Wang MC. Dissecting lipid droplet biology with coherent Raman scattering microscopy. J Cell Sci 2021; 135:261811. [PMID: 33975358 DOI: 10.1242/jcs.252353] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipid droplets (LDs) are lipid-rich organelles universally found in most cells. They serve as a key energy reservoir, actively participate in signal transduction and dynamically communicate with other organelles. LD dysfunction has been associated with a variety of diseases. The content level, composition and mobility of LDs are crucial for their physiological and pathological functions, and these different parameters of LDs are subject to regulation by genetic factors and environmental inputs. Coherent Raman scattering (CRS) microscopy utilizes optical nonlinear processes to probe the intrinsic chemical bond vibration, offering label-free, quantitative imaging of lipids in vivo with high chemical specificity and spatiotemporal resolution. In this Review, we provide an overview over the principle of CRS microscopy and its application in tracking different parameters of LDs in live cells and organisms. We also discuss the use of CRS microscopy in genetic screens to discover lipid regulatory mechanisms and in understanding disease-related lipid pathology.
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Affiliation(s)
- Tao Chen
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ahmet Yavuz
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng C Wang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
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6
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What Can Mushroom Proteins Teach Us about Lipid Rafts? MEMBRANES 2021; 11:membranes11040264. [PMID: 33917311 PMCID: PMC8067419 DOI: 10.3390/membranes11040264] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 12/25/2022]
Abstract
The lipid raft hypothesis emerged as a need to explain the lateral organization and behavior of lipids in the environment of biological membranes. The idea, that lipids segregate in biological membranes to form liquid-disordered and liquid-ordered states, was faced with a challenge: to show that lipid-ordered domains, enriched in sphingomyelin and cholesterol, actually exist in vivo. A great deal of indirect evidence and the use of lipid-binding probes supported this idea, but there was a lack of tools to demonstrate the existence of such domains in living cells. A whole new toolbox had to be invented to biochemically characterize lipid rafts and to define how they are involved in several cellular functions. A potential solution came from basic biochemical experiments in the late 1970s, showing that some mushroom extracts exert hemolytic activities. These activities were later assigned to aegerolysin-based sphingomyelin/cholesterol-specific cytolytic protein complexes. Recently, six sphingomyelin/cholesterol binding proteins from different mushrooms have been identified and have provided some insight into the nature of sphingomyelin/cholesterol-rich domains in living vertebrate cells. In this review, we dissect the accumulated knowledge and introduce the mushroom lipid raft binding proteins as molecules of choice to study the dynamics and origins of these liquid-ordered domains in mammalian cells.
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7
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Sibold J, Ahadi S, Werz DB, Steinem C. Chemically synthesized Gb 3 glycosphingolipids: tools to access their function in lipid membranes. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:109-126. [PMID: 32948883 PMCID: PMC8071800 DOI: 10.1007/s00249-020-01461-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 12/19/2022]
Abstract
Gb3 glycosphingolipids are the specific receptors for bacterial Shiga toxin. Whereas the trisaccharidic head group of Gb3 defines the specificity of Shiga toxin binding, the lipophilic part composed of sphingosine and different fatty acids is suggested to determine its localization within membranes impacting membrane organisation and protein binding eventually leading to protein internalisation. While most studies use Gb3 extracts, chemical synthesis provides a unique tool to access different tailor-made Gb3 glycosphingolipids. In this review, strategies to synthesize these complex glycosphingolipids are presented. Special emphasis is put on the preparation of Gb3 molecules differing only in their fatty acid part (saturated, unsaturated, α-hydroxylated and both, unsaturated and α-hydroxylated). With these molecules in hand, it became possible to investigate the phase behaviour of liquid ordered/liquid disordered supported membranes doped with the Gb3 species by means of fluorescence and atomic force microscopy. The results clearly highlight the influence of the different fatty acids of the Gb3 sphingolipids on the phase behaviour and the binding properties of Shiga toxin B subunits, even though the membranes were only doped with 5 mol% of the receptor lipid. To obtain fluorescent Gb3 derivatives, either fatty acid labelled Gb3 molecules or head group labelled ones were synthesized. These molecules enabled us to address the question, where the Gb3 sphingolipids are localized prior protein binding by means of fluorescence microscopy on giant unilamellar vesicles. The results again demonstrate that the fatty acid of Gb3 plays a pivotal role for the overall membrane organisation.
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Affiliation(s)
- Jeremias Sibold
- Georg-August-Universität Göttingen, Institute of Organic and Biomolecular Chemistry, Tammannstr. 2, 37077, Göttingen, Germany
| | - Somayeh Ahadi
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106, Braunschweig, Germany
| | - Daniel B Werz
- Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106, Braunschweig, Germany.
| | - Claudia Steinem
- Georg-August-Universität Göttingen, Institute of Organic and Biomolecular Chemistry, Tammannstr. 2, 37077, Göttingen, Germany.
- Max Planck Institute for Dynamics and Self Organization, Am Faßberg 17, 37077, Göttingen, Germany.
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8
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Samuel AZ, Miyaoka R, Ando M, Gaebler A, Thiele C, Takeyama H. Molecular profiling of lipid droplets inside HuH7 cells with Raman micro-spectroscopy. Commun Biol 2020; 3:372. [PMID: 32651434 PMCID: PMC7351753 DOI: 10.1038/s42003-020-1100-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/22/2020] [Indexed: 02/07/2023] Open
Abstract
Raman imaging has become an attractive technology in molecular biology because of its ability to detect multiple molecular components simultaneously without labeling. Two major limitations in accurately accounting for spectral features, viz., background removal and spectral unmixing, have been overcome by employing a modified and effective routine in multivariate curve resolution (MCR). With our improved strategy, we have spectrally isolated seven structurally specific biomolecules without any post-acquisition spectral treatments. Consequently, the isolated intensity profiles reflected concentrations of corresponding biomolecules with high statistical accuracy. Our study reveals the changes in the molecular composition of lipid droplets (LDs) inside HuH7 cells and its relation to the physiological state of the cell. Further, we show that the accurate separation of spectral components permits analysis of structural modification of molecules after cellular uptake. A detailed discussion is presented to highlight the potential of Raman spectroscopy with MCR in semi-quantitative molecular profiling of living cells. Samuel, Miyaoka et al. investigate the changes in the molecular composition of lipid droplets inside HuH7 cells and its relation to the physiological state of the cell, using Raman spectroscopy and multivariate curve resolution. This study underscores the importance of separation of spectral components in semi-quantitative molecular profiling of living cells.
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Affiliation(s)
- Ashok Zachariah Samuel
- Research Organization for Nano & Life Innovation, Waseda University, 513, Wasedatsurumaki-cho, Shinjuku-ku, Tokyo, 162-0041, Japan
| | - Rimi Miyaoka
- Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480, Japan
| | - Masahiro Ando
- Research Organization for Nano & Life Innovation, Waseda University, 513, Wasedatsurumaki-cho, Shinjuku-ku, Tokyo, 162-0041, Japan.,JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Anne Gaebler
- LIMES Life and Medical Sciences Institute, University of Bonn, Carl-Troll-Strasse 31, 53115, Bonn, Germany
| | - Christoph Thiele
- LIMES Life and Medical Sciences Institute, University of Bonn, Carl-Troll-Strasse 31, 53115, Bonn, Germany
| | - Haruko Takeyama
- Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480, Japan. .,Computational Bio Big-Data Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology and Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan. .,Insituture for Advances Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Tokyo, Japan.
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9
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Gorman BL, Kraft ML. High-Resolution Secondary Ion Mass Spectrometry Analysis of Cell Membranes. Anal Chem 2020; 92:1645-1652. [PMID: 31854976 DOI: 10.1021/acs.analchem.9b04492] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This Feature describes the use a Cameca NanoSIMS instrument for directly imaging specific lipid and protein species in the plasma membranes of mammalian cells with approximately 100 nm-lateral resolution and discusses how these analyses have already begun to transform fundamental concepts in the field of membrane biology. Secondary ion generation is discussed with emphasis on the constraints that affect the detection and identification of membrane components, and then the sample preparation methodologies and data analysis strategies that address these constraints are described.
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10
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Conrard L, Tyteca D. Regulation of Membrane Calcium Transport Proteins by the Surrounding Lipid Environment. Biomolecules 2019; 9:E513. [PMID: 31547139 PMCID: PMC6843150 DOI: 10.3390/biom9100513] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Abstract
Calcium ions (Ca2+) are major messengers in cell signaling, impacting nearly every aspect of cellular life. Those signals are generated within a wide spatial and temporal range through a large variety of Ca2+ channels, pumps, and exchangers. More and more evidences suggest that Ca2+ exchanges are regulated by their surrounding lipid environment. In this review, we point out the technical challenges that are currently being overcome and those that still need to be defeated to analyze the Ca2+ transport protein-lipid interactions. We then provide evidences for the modulation of Ca2+ transport proteins by lipids, including cholesterol, acidic phospholipids, sphingolipids, and their metabolites. We also integrate documented mechanisms involved in the regulation of Ca2+ transport proteins by the lipid environment. Those include: (i) Direct interaction inside the protein with non-annular lipids; (ii) close interaction with the first shell of annular lipids; (iii) regulation of membrane biophysical properties (e.g., membrane lipid packing, thickness, and curvature) directly around the protein through annular lipids; and (iv) gathering and downstream signaling of several proteins inside lipid domains. We finally discuss recent reports supporting the related alteration of Ca2+ and lipids in different pathophysiological events and the possibility to target lipids in Ca2+-related diseases.
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Affiliation(s)
- Louise Conrard
- CELL Unit, de Duve Institute and Université catholique de Louvain, UCL B1.75.05, avenue Hippocrate, 75, B-1200 Brussels, Belgium
| | - Donatienne Tyteca
- CELL Unit, de Duve Institute and Université catholique de Louvain, UCL B1.75.05, avenue Hippocrate, 75, B-1200 Brussels, Belgium.
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11
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Porta Siegel T, Ekroos K, Ellis SR. Reshaping Lipid Biochemistry by Pushing Barriers in Structural Lipidomics. Angew Chem Int Ed Engl 2019; 58:6492-6501. [PMID: 30601602 PMCID: PMC6563696 DOI: 10.1002/anie.201812698] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Indexed: 12/14/2022]
Abstract
Lipidomics is a rapidly growing field with numerous examples showing the importance of lipid molecules throughout biology. It has also shed light onto the vast and complex functions performed by many lipids that possess an immense diversity in molecular structures. Mass spectrometry (MS) is the tool of choice for analyzing lipids and has been the key catalyst driving the field forward. However, MS does not yet permit true molecular lipidomics wherein the identification and quantification of lipids having defined molecular structures can be routinely achieved. Here we describe recent advances in MS-based lipidomics that allow access to higher levels of molecular information in lipidomics experiments. These advances will form a key piece of the puzzle as the field moves towards systems characterization of lipids at the molecular level.
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Affiliation(s)
- Tiffany Porta Siegel
- Maastricht MultiModal Molecular Imaging (M4I) instituteDivision of Imaging Mass SpectrometryMaastricht UniversityUniversiteitssingel 506229 ERMaastrichtThe Netherlands
| | | | - Shane R. Ellis
- Maastricht MultiModal Molecular Imaging (M4I) instituteDivision of Imaging Mass SpectrometryMaastricht UniversityUniversiteitssingel 506229 ERMaastrichtThe Netherlands
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12
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Porta Siegel T, Ekroos K, Ellis SR. Reshaping Lipid Biochemistry by Pushing Barriers in Structural Lipidomics. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201812698] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Tiffany Porta Siegel
- Maastricht MultiModal Molecular Imaging (M4I) instituteDivision of Imaging Mass SpectrometryMaastricht University Universiteitssingel 50 6229 ER Maastricht The Netherlands
| | | | - Shane R. Ellis
- Maastricht MultiModal Molecular Imaging (M4I) instituteDivision of Imaging Mass SpectrometryMaastricht University Universiteitssingel 50 6229 ER Maastricht The Netherlands
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13
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Höglinger D. Bi- and Trifunctional Lipids for Visualization of Sphingolipid Dynamics within the Cell. Methods Mol Biol 2019; 1949:95-103. [PMID: 30790251 DOI: 10.1007/978-1-4939-9136-5_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Investigations into lipid localization and transport are often hampered by a lack of methods and tools to faithfully visualize lipids in the context of living cells, since fluorescent modifications drastically change lipid properties. Here, we describe the use of bifunctional as well as trifunctional sphingosine to reveal its subcellular localization via crosslinking, fixation, and specific staining by click reaction with a fluorophore. Additionally, these probes allow investigations into lipid metabolism as revealed by thin-layer chromatography.
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Affiliation(s)
- Doris Höglinger
- Heidelberg University Biochemistry Center, Heidelberg, Germany.
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14
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Mohamed ZH, Rhein C, Saied EM, Kornhuber J, Arenz C. FRET probes for measuring sphingolipid metabolizing enzyme activity. Chem Phys Lipids 2018; 216:152-161. [DOI: 10.1016/j.chemphyslip.2018.09.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 09/21/2018] [Indexed: 12/31/2022]
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15
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Young PA, Senkal CE, Suchanek AL, Grevengoed TJ, Lin DD, Zhao L, Crunk AE, Klett EL, Füllekrug J, Obeid LM, Coleman RA. Long-chain acyl-CoA synthetase 1 interacts with key proteins that activate and direct fatty acids into niche hepatic pathways. J Biol Chem 2018; 293:16724-16740. [PMID: 30190326 PMCID: PMC6204890 DOI: 10.1074/jbc.ra118.004049] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/24/2018] [Indexed: 12/17/2022] Open
Abstract
Fatty acid channeling into oxidation or storage modes depends on physiological conditions and hormonal signaling. However, the directionality of this channeling may also depend on the association of each of the five acyl-CoA synthetase isoforms with specific protein partners. Long-chain acyl-CoA synthetases (ACSLs) catalyze the conversion of long-chain fatty acids to fatty acyl-CoAs, which are then either oxidized or used in esterification reactions. In highly oxidative tissues, ACSL1 is located on the outer mitochondrial membrane (OMM) and directs fatty acids into mitochondria for β-oxidation. In the liver, however, about 50% of ACSL1 is located on the endoplasmic reticulum (ER) where its metabolic function is unclear. Because hepatic fatty acid partitioning is likely to require the interaction of ACSL1 with other specific proteins, we used an unbiased protein interaction technique, BioID, to discover ACSL1-binding partners in hepatocytes. We targeted ACSL1 either to the ER or to the OMM of Hepa 1-6 cells as a fusion protein with the Escherichia coli biotin ligase, BirA*. Proteomic analysis identified 98 proteins that specifically interacted with ACSL1 at the ER, 55 at the OMM, and 43 common to both subcellular locations. We found subsets of peroxisomal and lipid droplet proteins, tethering proteins, and vesicle proteins, uncovering a dynamic role for ACSL1 in organelle and lipid droplet interactions. Proteins involved in lipid metabolism were also identified, including acyl-CoA-binding proteins and ceramide synthase isoforms 2 and 5. Our results provide fundamental and detailed insights into protein interaction networks that control fatty acid metabolism.
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Affiliation(s)
| | - Can E Senkal
- the Department of Medicine, Stony Brook University, Stony Brook, New York 11794, and
| | | | | | | | | | | | - Eric L Klett
- From the Departments of Nutrition and
- Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Joachim Füllekrug
- the Molecular Cell Biology Laboratory, Internal Medicine IV, Heidelberg University Hospital, Otto-Meyerhof-Zentrum, University of Heidelberg, 69120 Heidelberg, Germany
| | - Lina M Obeid
- the Department of Medicine, Stony Brook University, Stony Brook, New York 11794, and
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16
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Zaidi A, Alsvik IL, Øpstad CL, Martin D, Rebman E, Voss G, Sliwka HR, Partali V. Forgotten fatty acids-Surface properties supply conclusive evidence for including carotenoic acids. Chem Phys Lipids 2018; 216:48-53. [PMID: 30261174 DOI: 10.1016/j.chemphyslip.2018.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/02/2018] [Accepted: 09/03/2018] [Indexed: 10/28/2022]
Abstract
The term "fatty acids" is conceptually well defined with regard to fats, whose extent of saturation or unsaturation is precisely indicated in the content description of foodstuff. In contrast, the term "fatty acid" gives no hint of being associated with "soap" (Na and K salts of fatty acids). Fatty acids in edible fats or in cleaning soaps have one thing in common: they are colorless. The prevalence of colorless fats and unadulterated white soaps has ensured that fatty acids are not associated with color. However, colored conjugated polyunsaturated fatty acids do exist, occurring abundantly in nature or manufactured at large scale. We endeavor to extricate conjugated polyenoic acids from oblivion by Based on the presented results (alkalicarotenoates have similar surface properties to alkalicarboxylates, carotenoic acids react like carboxylic acids to lipids), we argue for inclusion of conjugated carotenoic acids in fatty acid inventories and organic chemistry textbooks. Carotenoic acids and -salts have outstanding qualities by combining visibility and traceability with biological activity.
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Affiliation(s)
- Asma Zaidi
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Inger Lise Alsvik
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Christer L Øpstad
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Daniel Martin
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Eduard Rebman
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Georg Voss
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Hans-Richard Sliwka
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.
| | - Vassilia Partali
- Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
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17
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Peroxisomes and cancer: The role of a metabolic specialist in a disease of aberrant metabolism. Biochim Biophys Acta Rev Cancer 2018; 1870:103-121. [PMID: 30012421 DOI: 10.1016/j.bbcan.2018.07.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/30/2018] [Accepted: 07/10/2018] [Indexed: 01/02/2023]
Abstract
Cancer is irrevocably linked to aberrant metabolic processes. While once considered a vestigial organelle, we now know that peroxisomes play a central role in the metabolism of reactive oxygen species, bile acids, ether phospholipids (e.g. plasmalogens), very-long chain, and branched-chain fatty acids. Immune system evasion is a hallmark of cancer, and peroxisomes have an emerging role in the regulation of cellular immune responses. Investigations of individual peroxisome proteins and metabolites support their pro-tumorigenic functions. However, a significant knowledge gap remains regarding how individual functions of proteins and metabolites of the peroxisome orchestrate its potential role as a pro-tumorigenic organelle. This review highlights new advances in our understanding of biogenesis, enzymatic functions, and autophagic degradation of peroxisomes (pexophagy), and provides evidence linking these activities to tumorigenesis. Finally, we propose avenues that may be exploited to target peroxisome-related processes as a mode of combatting cancer.
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18
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Hunter CD, Guo T, Daskhan G, Richards MR, Cairo CW. Synthetic Strategies for Modified Glycosphingolipids and Their Design as Probes. Chem Rev 2018; 118:8188-8241. [DOI: 10.1021/acs.chemrev.8b00070] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Carmanah D. Hunter
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Tianlin Guo
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Gour Daskhan
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Michele R. Richards
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Christopher W. Cairo
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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19
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Walter T, Schlegel J, Burgert A, Kurz A, Seibel J, Sauer M. Incorporation studies of clickable ceramides in Jurkat cell plasma membranes. Chem Commun (Camb) 2018; 53:6836-6839. [PMID: 28597878 DOI: 10.1039/c7cc01220a] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The incorporation properties of ceramide analogues for click chemistry in Jurkat T cells were investigated. The analogues varied in the acyl chain length and the position of the functional group for click chemistry. Fluorescence microscopy studies including anisotropy and quenching experiments showed significant differences in the accessibility of the functional group indicating different incorporation properties into the plasma membrane.
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Affiliation(s)
- T Walter
- Institute for Organic Chemistry, Julius-Maximilians University Würzburg, Am Hubland C1, 97074 Würzburg, Germany.
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20
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Poppelreuther M, Sander S, Minden F, Dietz MS, Exner T, Du C, Zhang I, Ehehalt F, Knüppel L, Domschke S, Badenhop A, Staudacher S, Ehehalt R, Stremmel W, Thiele C, Heilemann M, Füllekrug J. The metabolic capacity of lipid droplet localized acyl-CoA synthetase 3 is not sufficient to support local triglyceride synthesis independent of the endoplasmic reticulum in A431 cells. Biochim Biophys Acta Mol Cell Biol Lipids 2018. [PMID: 29526665 DOI: 10.1016/j.bbalip.2018.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
ACSL3 is the only long chain fatty acyl-CoA synthetase consistently found on growing and mature lipid droplets (LDs), suggesting that this specific localization has biological relevance. Current models for LD growth propose that triglycerides are synthesized by enzymes at the LD surface, with activated fatty acids provided by LD localized ACSL3, thus allowing growth independent of the ER. Here, we tested this hypothesis by quantifying ACSL3 on LDs from human A431 cells. RNAi of ACSL3 reduced the oleoyl-CoA synthetase activity by 83%, suggesting that ACSL3 is by far the dominant enzyme of A431 cells. Molar quantification revealed that there are 1.4 million ACSL3 molecules within a single cell. Metabolic labeling indicated that each ACSL3 molecule contributed a net gain of 3.1 oleoyl-CoA/s. 3D reconstruction of confocal images demonstrated that 530 individual lipid droplets were present in an average oleate fed A431 cell. A representative single lipid droplet with a diameter of 0.66 μm contained 680 ACSL3 molecules on the surface. Subcellular fractionation showed that at least 68% of ACSL3 remain at the ER even during extensive fatty acid supplementation. High resolution single molecule microscopy confirmed the abundance of cytoplasmic ACSL3 outside of LDs. Model calculations for triglyceride synthesis using only LD localized ACSL3 gave significant slower growth of LDs as observed experimentally. In conclusion, although ACSL3 is an abundant enzyme on A431 LDs, the metabolic capacity is not sufficient to account for LD growth solely by the local synthesis of triglycerides.
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Affiliation(s)
| | - Simone Sander
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Fadil Minden
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Marina S Dietz
- Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Tarik Exner
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Chen Du
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Ingrid Zhang
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Friedrich Ehehalt
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Laura Knüppel
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Susanne Domschke
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Anna Badenhop
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Sarah Staudacher
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Robert Ehehalt
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Wolfgang Stremmel
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Christoph Thiele
- Life and Medical Sciences Institute, University of Bonn, Germany
| | - Mike Heilemann
- Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany.
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21
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Abstract
Membranes can adopt distinct phases. The endoplasmic reticulum (ER) is the largest membrane system inside cells and also harbors the richest metabolic activity including lipid synthesis. Unlike plasma membrane where separated “lipid raft” domains have been predicted and observed, ER membrane is thought to be uniformly fluidic. However, such understanding is based on biophysical studies of model membrane under thermodynamic equilibrium. It remains unclear whether and how lipid synthesis activity perturbs the equilibrium and promotes phase segregation in ER membrane. Herein, we utilized coherent Raman imaging technique to track lipid synthesis and surprisingly revealed solid-like domains emerging from liquid ER membrane. Interestingly, this phenomenon can be tuned by the incoming nutrient source, demonstrating the susceptibility of ER membrane to nonequilibrium modulation. Membrane phase behavior has been well characterized in model membranes in vitro under thermodynamic equilibrium state. However, the widely observed differences between biological membranes and their in vitro counterparts are placing more emphasis on nonequilibrium factors, including influx and efflux of lipid molecules. The endoplasmic reticulum (ER) is the largest cellular membrane system and also the most metabolically active organelle responsible for lipid synthesis. However, how the nonequilibrium metabolic activity modulates ER membrane phase has not been investigated. Here, we studied the phase behavior of functional ER in the context of lipid metabolism. Utilizing advanced vibrational imaging technique, that is, stimulated Raman scattering microscopy, we discovered that metabolism of palmitate, a prevalent saturated fatty acid (SFA), could drive solid-like domain separation from the presumably uniformly fluidic ER membrane, a previously unknown phenomenon. The potential of various fatty acids to induce solid phase can be predicted by the transition temperatures of their major metabolites. Interplay between saturated and unsaturated fatty acids is also observed. Hence, our study sheds light on cellular membrane biophysics by underscoring the nonequilibrium metabolic status of living cell.
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22
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Patalag LJ, Sibold J, Schütte OM, Steinem C, Werz DB. Gb 3 Glycosphingolipids with Fluorescent Oligoene Fatty Acids: Synthesis and Phase Behavior in Model Membranes. Chembiochem 2017; 18:2171-2178. [PMID: 28941080 DOI: 10.1002/cbic.201700414] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Indexed: 12/11/2022]
Abstract
Glycosphingolipids are involved in a number of physiological and pathophysiological processes, and they serve as receptors for a variety of bacterial toxins and viruses. To investigate their function in lipid membranes, fluorescently labeled glycosphingolipids are highly desirable. Herein, a synthetic route to access Gb3 glycosphingolipids with fluorescently labeled fatty acids, consisting of pentaene and hexaene moieties either at the terminus or in the middle of the acyl chain, has been developed. The fluorescent properties of the Gb3 derivatives were investigated in small unilamellar vesicles composed of a raft-like mixture. Phase-separated giant unilamellar vesicles (GUVs) allowed the quantification of the apparent partitioning coefficients of the Gb3 compounds by means of confocal fluorescence laser scanning microscopy. The determined partition coefficients demonstrate that the Gb3 derivatives are preferentially localized in the liquid-disordered (ld ) phase. To analyze whether the compounds behave like their physiological counterparts, Cy3-labeled (Cy: cyanine) Shiga toxin B subunits (STxB) were specifically bound to Gb3 -doped GUVs. However, the protein was favorably localized in the ld phase, in contrast to results reported for STxB bound to naturally occurring Gb3 , which is discussed in terms of the packing density of the lipids in the liquid-ordered (lo ) phase.
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Affiliation(s)
- Lukas J Patalag
- TU Braunschweig, Institut für Organische Chemie, Hagenring 30, 38106, Braunschweig, Germany
| | - Jeremias Sibold
- Georg-August-Universität Göttingen, Institut für Organische und Biomolekulare Chemie, Tammannstrasse 2, 37077, Göttingen, Germany
| | - Ole M Schütte
- Georg-August-Universität Göttingen, Institut für Organische und Biomolekulare Chemie, Tammannstrasse 2, 37077, Göttingen, Germany
| | - Claudia Steinem
- Georg-August-Universität Göttingen, Institut für Organische und Biomolekulare Chemie, Tammannstrasse 2, 37077, Göttingen, Germany
| | - Daniel B Werz
- TU Braunschweig, Institut für Organische Chemie, Hagenring 30, 38106, Braunschweig, Germany
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23
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Mo GCH, Yip CM. Structural templating of J-aggregates: Visualizing bis(monoacylglycero)phosphate domains in live cells. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1687-1695. [PMID: 28844737 DOI: 10.1016/j.bbapap.2017.07.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/13/2017] [Accepted: 07/24/2017] [Indexed: 12/23/2022]
Abstract
Identifying the key structural and dynamical determinants that drive the association of biomolecules, whether in solution, or perhaps more importantly in a membrane environment, has critical implications for our understanding of cellular dynamics, processes, and signaling. With recent advances in high-resolution imaging techniques, from the development of new molecular labels to technical advances in imaging methodologies and platforms, researchers are now reaping the benefits of being able to directly characterize and quantify local dynamics, structures, and conformations in live cells and tissues. These capabilities are providing unique insights into association stoichiometries, interactions, and structures on sub-micron length scales. We previously examined the role of lipid headgroup chemistry and phase state in guiding the formation of pseudoisocyanine (PIC) dye J-aggregates on supported planar bilayers [Langmuir, 25, 10719]. We describe here how these same J-aggregates can report on the in situ formation of organellar membrane domains in live cells. Live cell hyperspectral confocal microscopy using GFP-conjugated GTPase markers of early (Rab5) and late (Rab7) endosomes revealed that the PIC J-aggregates were confined to domains on either the limiting membrane or intralumenal vesicles (ILV) of late endosomes, known to be enriched in the anionic lipid bis(monoacylglycero)phosphate (BMP). Correlated confocal fluorescence - atomic force microscopy performed on endosomal membrane-mimetic supported planar lipid bilayers confirmed BMP-specific templating of the PIC J-aggregates. These data provide strong evidence for the formation of BMP-rich lipid domains during multivesicular body formation and portend the application of structured dye aggregates as markers of cellular membrane domain structure, size, and formation.
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Affiliation(s)
- Gary C H Mo
- Department of Chemical Engineering and Applied Chemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA
| | - Christopher M Yip
- Department of Biochemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Department of Chemical Engineering and Applied Chemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Institute of Biomaterials and Biomedical Engineering, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada.
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24
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Honsho M, Fujiki Y. Plasmalogen homeostasis - regulation of plasmalogen biosynthesis and its physiological consequence in mammals. FEBS Lett 2017; 591:2720-2729. [PMID: 28686302 DOI: 10.1002/1873-3468.12743] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 06/28/2015] [Accepted: 06/29/2016] [Indexed: 11/06/2022]
Abstract
Plasmalogens, mostly ethanolamine-containing alkenyl ether phospholipids, are a major subclass of glycerophospholipids. Plasmalogen synthesis is initiated in peroxisomes and completed in the endoplasmic reticulum. The absence of plasmalogens in several organs of peroxisome biogenesis-defective patients suggests that the de novo synthesis of plasmalogens plays a pivotal role in its homeostasis in tissues. Plasmalogen synthesis is regulated by modulating the stability of fatty acyl-CoA reductase 1 on peroxisomal membranes, a rate-limiting enzyme in plasmalogen synthesis, by sensing plasmalogens in the inner leaflet of plasma membranes. Dysregulation of plasmalogen homeostasis impairs cholesterol biosynthesis by altering the stability of squalene monooxygenase, a key enzyme in cholesterol biosynthesis, implying physiological consequences of plasmalogen homeostasis with respect to cholesterol metabolism in cells, as well as in organs such as the liver.
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Affiliation(s)
- Masanori Honsho
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Yukio Fujiki
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
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25
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Advances on the Transfer of Lipids by Lipid Transfer Proteins. Trends Biochem Sci 2017; 42:516-530. [PMID: 28579073 PMCID: PMC5486777 DOI: 10.1016/j.tibs.2017.05.001] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/02/2017] [Accepted: 05/03/2017] [Indexed: 12/22/2022]
Abstract
Transfer of lipid across the cytoplasm is an essential process for intracellular lipid traffic. Lipid transfer proteins (LTPs) are defined by highly controlled in vitro experiments. The functional relevance of these is supported by evidence for the same reactions inside cells. Major advances in the LTP field have come from structural bioinformatics identifying new LTPs, and from the development of countercurrent models for LTPs. However, the ultimate aim is to unite in vitro and in vivo data, and this is where much progress remains to be made. Even where in vitro and in vivo experiments align, rates of transfer tend not to match. Here we set out some of the advances that might test how LTPs work. LTPs facilitate the essential movement of lipid across aqueous spaces and are defined by in vitro experiments. Recent developments include a novel concept of countercurrent lipid transfer and identification of additional LTP families by bioinformatics. In vivo and in vitro data have yet to converge to one complete model. Advances in in vitro characterisation of LTPs provide an opportunity to unite biochemical experimentation to cellular function.
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26
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Nevo-Yassaf I, Lovelle M, Nahmias Y, Hirschberg K, Sklan EH. Live cell imaging and analysis of lipid droplets biogenesis in hepatatis C virus infected cells. Methods 2017; 127:30-36. [PMID: 28526563 DOI: 10.1016/j.ymeth.2017.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/11/2017] [Accepted: 05/13/2017] [Indexed: 01/16/2023] Open
Abstract
Lipid droplets (LDs) are regulated neutral lipid storage organelles having a central role in numerous cellular processes as well as in various pathologies such as metabolic disorders, immune responses and during pathogen infection. Due to the growing significance of LDs, extensive efforts are made to study the mechanism and the dynamics of their formation and life history and how are these diverted or modified by pathogens. Real-time visualization of lipid droplet biogenesis can assist in clarifying these and other important issues and may have implications towards understanding the pathogenesis of the associated diseases. Typically, LDs are post-experimentally stained using lipophilic dyes and are visualized under a microscope. Alternatively, overexpression of LD-associated proteins or immunofluorescence analyses are used to identify and follow LDs. These experimental approaches only examine a single end point of the experiment and cannot answer questions regarding LD dynamics. Here, we describe a simple and novel experimental setting that allows real-time fluorescence staining and detection of LDs in cultured living as well as infected cells. This method is quick and simple and is not restricted to a specific dye or cell line. Using this system, the biogenesis of LDs and their growth is demonstrated in cells infected with hepatitis C virus (HCV), confirming the strength of this method and the wide range of its applications.
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Affiliation(s)
- Inbar Nevo-Yassaf
- Department of Pathology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Marcos Lovelle
- Department of Pathology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yaakov Nahmias
- School of Engineering, Faculty of Science, The Hebrew University, Jerusalem 91904, Israel
| | - Koret Hirschberg
- Department of Pathology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Ella H Sklan
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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27
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Kühn S, Lopez-Montero N, Chang YY, Sartori-Rupp A, Enninga J. Imaging macropinosomes during Shigella infections. Methods 2017; 127:12-22. [PMID: 28522322 DOI: 10.1016/j.ymeth.2017.05.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/11/2017] [Accepted: 05/10/2017] [Indexed: 12/21/2022] Open
Abstract
Macropinocytosis is the uptake of extracellular fluid within vesicles of varying size that takes place during numerous cellular processes in a large variety of cells. A growing number of pathogens, including viruses, parasites, and bacteria are known to induce macropinocytosis during their entry into targeted host cells. We have recently discovered that the human enteroinvasive, bacterial pathogen Shigella causes in situ macropinosome formation during its entry into epithelial cells. These infection-associated macropinosomes are not generated to ingest the bacteria, but are instead involved in Shigella's intracellular niche formation. They make contacts with the phagocytosed shigellae to promote vacuolar membrane rupture and their cytosolic release. Here, we provide an overview of the different imaging approaches that are currently used to analyze macropinocytosis during infectious processes with a focus on Shigella entry. We detail the advantages and disadvantages of genetically encoded reporters as well as chemical probes to trace fluid phase uptake. In addition, we report how such reporters can be combined with ultrastructural approaches for correlative light electron microscopy either in thin sections or within large volumes. The combined imaging techniques introduced here provide a detailed characterization of macropinosomes during bacterial entry, which, apart from Shigella, are relevant for numerous other ones, including Salmonella, Brucella or Mycobacteria.
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Affiliation(s)
- Sonja Kühn
- Department of Cell Biology and Infection, Institut Pasteur, Paris, France
| | | | - Yuen-Yan Chang
- Department of Cell Biology and Infection, Institut Pasteur, Paris, France
| | - Anna Sartori-Rupp
- Department of Cell Biology and Infection, Institut Pasteur, Paris, France
| | - Jost Enninga
- Department of Cell Biology and Infection, Institut Pasteur, Paris, France.
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28
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Burgert A, Schlegel J, Bécam J, Doose S, Bieberich E, Schubert-Unkmeir A, Sauer M. Characterization of Plasma Membrane Ceramides by Super-Resolution Microscopy. Angew Chem Int Ed Engl 2017; 56:6131-6135. [PMID: 28379629 DOI: 10.1002/anie.201700570] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Indexed: 01/04/2023]
Abstract
The sphingolipid ceramide regulates cellular processes such as differentiation, proliferation, growth arrest, and apoptosis. Ceramide-rich membrane areas promote structural changes within the plasma membrane that segregate membrane receptors and affect membrane curvature and vesicle formation, fusion, and trafficking. Ceramides were labeled by immunocytochemistry to visualize their distribution on the plasma membrane of different cells with virtually molecular resolution by direct stochastic optical reconstruction microscopy (dSTORM). Super-resolution images show that independent of labeling conditions and cell type 50-60 % of all membrane ceramides are located in ceramide-rich platforms (CRPs) with a size of about 75 nm that are composed of at least about 20 ceramides. Treatment of cells with Bacillus cereus sphingomyelinase (bSMase) increases the overall ceramide concentration in the plasma membrane, the quantity of CRPs, and their size. Simultaneously, the ceramide concentration in CRPs increases approximately twofold.
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Affiliation(s)
- Anne Burgert
- Department of Biotechnology and Biophysics, Julius Maximilian University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Jan Schlegel
- Department of Biotechnology and Biophysics, Julius Maximilian University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Jérôme Bécam
- Institute of Hygiene and Microbiology, Julius Maximilian University Würzburg, 97080, Würzburg, Germany
| | - Sören Doose
- Department of Biotechnology and Biophysics, Julius Maximilian University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Erhard Bieberich
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | | | - Markus Sauer
- Department of Biotechnology and Biophysics, Julius Maximilian University Würzburg, Am Hubland, 97074, Würzburg, Germany
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29
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Burgert A, Schlegel J, Bécam J, Doose S, Bieberich E, Schubert‐Unkmeir A, Sauer M. Characterization of Plasma Membrane Ceramides by Super‐Resolution Microscopy. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201700570] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Anne Burgert
- Department of Biotechnology and Biophysics Julius Maximilian University Würzburg Am Hubland 97074 Würzburg Germany
| | - Jan Schlegel
- Department of Biotechnology and Biophysics Julius Maximilian University Würzburg Am Hubland 97074 Würzburg Germany
| | - Jérôme Bécam
- Institute of Hygiene and Microbiology Julius Maximilian University Würzburg 97080 Würzburg Germany
| | - Sören Doose
- Department of Biotechnology and Biophysics Julius Maximilian University Würzburg Am Hubland 97074 Würzburg Germany
| | - Erhard Bieberich
- Department of Neuroscience and Regenerative Medicine Medical College of Georgia Augusta University Augusta GA 30912 USA
| | | | - Markus Sauer
- Department of Biotechnology and Biophysics Julius Maximilian University Würzburg Am Hubland 97074 Würzburg Germany
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30
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Kinoshita M, Suzuki KGN, Matsumori N, Takada M, Ano H, Morigaki K, Abe M, Makino A, Kobayashi T, Hirosawa KM, Fujiwara TK, Kusumi A, Murata M. Raft-based sphingomyelin interactions revealed by new fluorescent sphingomyelin analogs. J Cell Biol 2017; 216:1183-1204. [PMID: 28330937 PMCID: PMC5379944 DOI: 10.1083/jcb.201607086] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 12/30/2016] [Accepted: 02/02/2017] [Indexed: 01/01/2023] Open
Abstract
Sphingomyelin (SM) has been proposed to form cholesterol-dependent raft domains and sphingolipid domains in the plasma membrane (PM). How SM contributes to the formation and function of these domains remains unknown, primarily because of the scarcity of suitable fluorescent SM analogs. We developed new fluorescent SM analogs by conjugating a hydrophilic fluorophore to the SM choline headgroup without eliminating its positive charge, via a hydrophilic nonaethylene glycol linker. The new analogs behaved similarly to the native SM in terms of their partitioning behaviors in artificial liquid order-disorder phase-separated membranes and detergent-resistant PM preparations. Single fluorescent molecule tracking in the live-cell PM revealed that they indirectly interact with each other in cholesterol- and sphingosine backbone-dependent manners, and that, for ∼10-50 ms, they undergo transient colocalization-codiffusion with a glycosylphosphatidylinositol (GPI)-anchored protein, CD59 (in monomers, transient-dimer rafts, and clusters), in CD59-oligomer size-, cholesterol-, and GPI anchoring-dependent manners. These results suggest that SM continually and rapidly exchanges between CD59-associated raft domains and the bulk PM.
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Affiliation(s)
- Masanao Kinoshita
- Lipid Active Structure Project, Exploratory Research for Advanced Technology Organization, Japan Science and Technology Agency, Osaka University, Osaka 560-0043, Japan.,Project Research Center for Fundamental Science, Osaka University, Osaka 560-0043, Japan
| | - Kenichi G N Suzuki
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507, Japan.,The Institute for Stem Cell Biology and Regenerative Medicine, The National Centre for Biological Sciences, Bangalore 560065, India
| | - Nobuaki Matsumori
- Lipid Active Structure Project, Exploratory Research for Advanced Technology Organization, Japan Science and Technology Agency, Osaka University, Osaka 560-0043, Japan .,Project Research Center for Fundamental Science, Osaka University, Osaka 560-0043, Japan.,Department of Chemistry, Graduate School of Science, Osaka University, Osaka 560-0043, Japan
| | - Misa Takada
- Department of Chemistry, Graduate School of Science, Osaka University, Osaka 560-0043, Japan
| | - Hikaru Ano
- Lipid Active Structure Project, Exploratory Research for Advanced Technology Organization, Japan Science and Technology Agency, Osaka University, Osaka 560-0043, Japan.,Project Research Center for Fundamental Science, Osaka University, Osaka 560-0043, Japan
| | - Kenichi Morigaki
- Research Center for Environmental Genomics, Kobe University, Kobe 657-8501, Japan
| | - Mitsuhiro Abe
- Cellular Informatics Laboratory, Institute of Physical and Chemical Research, Wako, Saitama 351-0198, Japan
| | - Asami Makino
- Cellular Informatics Laboratory, Institute of Physical and Chemical Research, Wako, Saitama 351-0198, Japan
| | - Toshihide Kobayashi
- UMR 7213 Centre National de la Recherche Scientifique, University of Strasbourg, Illkirch 67401, France
| | - Koichiro M Hirosawa
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Takahiro K Fujiwara
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Akihiro Kusumi
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507, Japan .,Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.,Membrane Cooperativity Unit, Okinawa Institute of Science and Technology, Okinawa 904-0412, Japan
| | - Michio Murata
- Lipid Active Structure Project, Exploratory Research for Advanced Technology Organization, Japan Science and Technology Agency, Osaka University, Osaka 560-0043, Japan.,Project Research Center for Fundamental Science, Osaka University, Osaka 560-0043, Japan.,Department of Chemistry, Graduate School of Science, Osaka University, Osaka 560-0043, Japan
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31
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Plasmalogen biosynthesis is spatiotemporally regulated by sensing plasmalogens in the inner leaflet of plasma membranes. Sci Rep 2017; 7:43936. [PMID: 28272479 PMCID: PMC5341075 DOI: 10.1038/srep43936] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 01/31/2017] [Indexed: 12/14/2022] Open
Abstract
Alkenyl ether phospholipids are a major sub-class of ethanolamine- and choline-phospholipids in which a long chain fatty alcohol is attached at the sn-1 position through a vinyl ether bond. Biosynthesis of ethanolamine-containing alkenyl ether phospholipids, plasmalogens, is regulated by modulating the stability of fatty acyl-CoA reductase 1 (Far1) in a manner dependent on the level of cellular plasmalogens. However, precise molecular mechanisms underlying the regulation of plasmalogen synthesis remain poorly understood. Here we show that degradation of Far1 is accelerated by inhibiting dynamin-, Src kinase-, or flotillin-1-mediated endocytosis without increasing the cellular level of plasmalogens. By contrast, Far1 is stabilized by sequestering cholesterol with nystatin. Moreover, abrogation of the asymmetric distribution of plasmalogens in the plasma membrane by reducing the expression of CDC50A encoding a β-subunit of flippase elevates the expression level of Far1 and plasmalogen synthesis without reducing the total cellular level of plasmalogens. Together, these results support a model that plasmalogens localised in the inner leaflet of the plasma membranes are sensed for plasmalogen homeostasis in cells, thereby suggesting that plasmalogen synthesis is spatiotemporally regulated by monitoring cellular level of plasmalogens.
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32
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Trifunctional lipid probes for comprehensive studies of single lipid species in living cells. Proc Natl Acad Sci U S A 2017; 114:1566-1571. [PMID: 28154130 DOI: 10.1073/pnas.1611096114] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Lipid-mediated signaling events regulate many cellular processes. Investigations of the complex underlying mechanisms are difficult because several different methods need to be used under varying conditions. Here we introduce multifunctional lipid derivatives to study lipid metabolism, lipid-protein interactions, and intracellular lipid localization with a single tool per target lipid. The probes are equipped with two photoreactive groups to allow photoliberation (uncaging) and photo-cross-linking in a sequential manner, as well as a click-handle for subsequent functionalization. We demonstrate the versatility of the design for the signaling lipids sphingosine and diacylglycerol; uncaging of the probe for these two species triggered calcium signaling and intracellular protein translocation events, respectively. We performed proteomic screens to map the lipid-interacting proteome for both lipids. Finally, we visualized a sphingosine transport deficiency in patient-derived Niemann-Pick disease type C fibroblasts by fluorescence as well as correlative light and electron microscopy, pointing toward the diagnostic potential of such tools. We envision that this type of probe will become important for analyzing and ultimately understanding lipid signaling events in a comprehensive manner.
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33
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Barisch C, Soldati T. Mycobacterium marinum Degrades Both Triacylglycerols and Phospholipids from Its Dictyostelium Host to Synthesise Its Own Triacylglycerols and Generate Lipid Inclusions. PLoS Pathog 2017; 13:e1006095. [PMID: 28103313 PMCID: PMC5245797 DOI: 10.1371/journal.ppat.1006095] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/28/2016] [Indexed: 12/21/2022] Open
Abstract
During a tuberculosis infection and inside lipid-laden foamy macrophages, fatty acids (FAs) and sterols are the major energy and carbon source for Mycobacterium tuberculosis. Mycobacteria can be found both inside a vacuole and the cytosol, but how this impacts their access to lipids is not well appreciated. Lipid droplets (LDs) store FAs in form of triacylglycerols (TAGs) and are energy reservoirs of prokaryotes and eukaryotes. Using the Dictyostelium discoideum/Mycobacterium marinum infection model we showed that M. marinum accesses host LDs to build up its own intracytosolic lipid inclusions (ILIs). Here, we show that host LDs aggregate at regions of the bacteria that become exposed to the cytosol, and appear to coalesce on their hydrophobic surface leading to a transfer of diacylglycerol O-acyltransferase 2 (Dgat2)-GFP onto the bacteria. Dictyostelium knockout mutants for both Dgat enzymes are unable to generate LDs. Instead, the excess of exogenous FAs is esterified predominantly into phospholipids, inducing uncontrolled proliferation of the endoplasmic reticulum (ER). Strikingly, in absence of host LDs, M. marinum alternatively exploits these phospholipids, resulting in rapid reversal of ER-proliferation. In addition, the bacteria are unable to restrict their acquisition of lipids from the dgat1&2 double knockout leading to vast accumulation of ILIs. Recent data indicate that the presence of ILIs is one of the characteristics of dormant mycobacteria. During Dictyostelium infection, ILI formation in M. marinum is not accompanied by a significant change in intracellular growth and a reduction in metabolic activity, thus providing evidence that storage of neutral lipids does not necessarily induce dormancy.
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Affiliation(s)
- Caroline Barisch
- Department of Biochemistry, Science II, University of Geneva, 30 quai Ernest-Ansermet, Geneva, Switzerland
- * E-mail:
| | - Thierry Soldati
- Department of Biochemistry, Science II, University of Geneva, 30 quai Ernest-Ansermet, Geneva, Switzerland
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34
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Patalag LJ, Werz DB. Benzothiadiazole oligoene fatty acids: fluorescent dyes with large Stokes shifts. Beilstein J Org Chem 2016; 12:2739-2747. [PMID: 28144344 PMCID: PMC5238556 DOI: 10.3762/bjoc.12.270] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 12/01/2016] [Indexed: 11/23/2022] Open
Abstract
Herein, we report on the synthesis and characterization of novel fluorescent fatty acids with large Stokes shifts. Three examples consisting of the same number of carbon atoms and thus of similar chain length are presented differing in their degree of unsaturation. As major fluorogenic contributor at the terminus benzo[c][1,2,5]thiadiazole was used. Respective syntheses based on Wittig reactions followed by iodine-mediated isomerization are presented. The absorption properties are modulated by the number of conjugated C=C double bonds of the oligoene chain ranging from one to three. Large Stokes shifts of about 4900-5700 cm-1 and fluorescence quantum yields of up to 0.44 were observed.
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Affiliation(s)
- Lukas J Patalag
- Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Daniel B Werz
- Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
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35
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Probing phosphoethanolamine-containing lipids in membranes with duramycin/cinnamycin and aegerolysin proteins. Biochimie 2016; 130:81-90. [DOI: 10.1016/j.biochi.2016.09.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/27/2016] [Indexed: 02/07/2023]
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36
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Cao C, Zhou D, Chen T, Streets AM, Huang Y. Label-Free Digital Quantification of Lipid Droplets in Single Cells by Stimulated Raman Microscopy on a Microfluidic Platform. Anal Chem 2016; 88:4931-9. [PMID: 27041129 DOI: 10.1021/acs.analchem.6b00862] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Quantitative characterization of a single-cell phenotype remains challenging. We combined a scalable microfluidic array of parallel cell culture chambers and stimulated Raman scattering (SRS) microscopy to quantitatively characterize the response of lipid droplet (LD) formation to free-fatty-acid stimuli with single-LD resolution at the single-cell level. By enabling the systematic live-cell imaging with SRS microscopy in a microfluidic device, we were able to quantify the morphology of over a thousand live cells in 10 different chemical environments and with 8 replicates for each culture condition, in a single experiment, and without relying on fluorescent labeling. We developed an image processing pipeline for cell segmentation and LD morphology quantification using dual-channel SRS images. This allows us to construct distributions of the morphological parameters of LDs in the cellular population and expose the vast phenotypic heterogeneity among genetically similar cells. Specifically, this approach provides an analytical tool for quantitatively investigating LD morphology in live cells in situ. With this high-throughput, high-resolution, and label-free method, we found that LD growth dynamics showed considerable cell to cell variation. Lipid accumulation in nonadipocyte cells is mainly reflected in the increase of LD number, as opposed to an increase in their size or lipid concentration. Our method allows statistical single-cell quantification of the LD distribution for further investigation of lipid metabolism and dynamic behavior, and also extends the possibility to couple with other "omics" technologies in the future.
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Affiliation(s)
- Chen Cao
- Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University , Beijing 100871, China
| | - Dong Zhou
- Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University , Beijing 100871, China.,College of Engineering, Peking University , Beijing 100871, China
| | - Tao Chen
- Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University , Beijing 100871, China.,College of Engineering, Peking University , Beijing 100871, China
| | - Aaron M Streets
- Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University , Beijing 100871, China.,College of Engineering, Peking University , Beijing 100871, China
| | - Yanyi Huang
- Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences, Peking University , Beijing 100871, China.,College of Engineering, Peking University , Beijing 100871, China.,Peking-Tsinghua Center for Life Sciences, Peking University , Beijing 100871, China
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37
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Kishimoto T, Ishitsuka R, Kobayashi T. Detectors for evaluating the cellular landscape of sphingomyelin- and cholesterol-rich membrane domains. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:812-829. [PMID: 26993577 DOI: 10.1016/j.bbalip.2016.03.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/09/2016] [Accepted: 03/09/2016] [Indexed: 12/11/2022]
Abstract
Although sphingomyelin and cholesterol are major lipids of mammalian cells, the detailed distribution of these lipids in cellular membranes remains still obscure. However, the recent development of protein probes that specifically bind sphingomyelin and/or cholesterol provides new information about the landscape of the lipid domains that are enriched with sphingomyelin or cholesterol or both. Here, we critically summarize the tools to study distribution and dynamics of sphingomyelin and cholesterol. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
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Affiliation(s)
| | - Reiko Ishitsuka
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Toshihide Kobayashi
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; INSERM U1060, Université Lyon 1, Villeurbanne 69621, France.
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38
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Nieves I, Abad JL, Montes LR, Goñi FM, Delgado A. Approaches to polyunsaturated sphingolipids: new conformationally restrained analogs with minimal structural modifications. Tetrahedron 2016. [DOI: 10.1016/j.tet.2015.11.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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39
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Merklinger E, Schloetel JG, Spitta L, Thiele C, Lang T. No Evidence for Spontaneous Lipid Transfer at ER-PM Membrane Contact Sites. J Membr Biol 2015; 249:41-56. [PMID: 26438553 DOI: 10.1007/s00232-015-9845-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/18/2015] [Indexed: 11/29/2022]
Abstract
Non-vesicular lipid transport steps play a crucial role in lipid trafficking and potentially include spontaneous exchange. Since membrane contact facilitates this lipid transfer, it is most likely to occur at membrane contact sites (MCS). However, to date it is unknown whether closely attached biological membranes exchange lipids spontaneously. We have set up a system for studying the exchange of lipids at MCS formed between the endoplasmic reticulum (ER) and the plasma membrane. Contact sites were stably anchored and the lipids cholesterol and phosphatidylcholine (PC) were not capable of transferring spontaneously into the opposed bilayer. We conclude that physical contact between two associated biological membranes is not sufficient for transfer of the lipids PC and cholesterol.
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Affiliation(s)
- Elisa Merklinger
- Department of Membrane Biochemistry, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
| | - Jan-Gero Schloetel
- Department of Membrane Biochemistry, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany
| | - Luis Spitta
- Department of Membrane Biochemistry, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.,Institute of Aerospace Medicine, German Aerospace Center (DLR), Linder Höhe, 51147, Cologne, Germany
| | - Christoph Thiele
- Department of Cell Biology of Lipids, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany
| | - Thorsten Lang
- Department of Membrane Biochemistry, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany
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40
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Nieves I, Artetxe I, Abad JL, Alonso A, Busto JV, Fajarí L, Montes LR, Sot J, Delgado A, Goñi FM. Fluorescent polyene ceramide analogues as membrane probes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:2484-2492. [PMID: 25658138 DOI: 10.1021/la505017x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Three ceramide analogues have been synthesized, with sphingosine-like chains containing five conjugated double bonds. Pentaene I has an N-palmitoyl acyl chain, while the other two pentaenes contain also a doxyl radical, respectively, at C5 (Penta5dox) and at C16 (Penta16dox) positions of the N-acyl chain. Pentaene I maximum excitation and emission wavelengths in a phospholipid bilayer are 353 and 478 nm, respectively. Pentaene I does not segregate from the other lipids in the way natural ceramide does, but rather mixes with them in a selective way according to the lipid phases involved. Fluorescence confocal microscopy studies show that when lipid domains in different physical states coexist, Pentaene I emission is higher in gel than in fluid domains, and in liquid-ordered than in liquid-disordered areas. Electron paramagnetic resonance of the pentaene doxyl probes confirms that these molecules are sensitive to the physical state of the bilayer. Calorimetric and fluorescence quenching experiments suggest that the lipids under study orient themselves in lipid bilayers with their polar moieties located at the lipid-water interface. The doxyl radical in the N-acyl chain quenches the fluorescence of the pentaene group when in close proximity. Because of this property, Penta16dox can detect gel-fluid transitions in phospholipids. The availability of probes for lipids in the gel phase is important in view of novel evidence for the existence of gel microdomains in cell membranes.
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Affiliation(s)
- Ingrid Nieves
- Spanish National Research Council (CSIC), Institute of Advanced Chemistry of Catalonia (IQACCSIC), Department of Biomedicinal Chemistry, Research Unit on Bioactive Molecules (RUBAM), Jordi Girona 1826, 08034 Barcelona, Spain
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41
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Microscopy of membrane lipids: how precisely can we define their distribution? Essays Biochem 2015; 57:81-91. [DOI: 10.1042/bse0570081] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Membrane lipids form the basic framework of biological membranes by forming the lipid bilayer, but it is becoming increasingly clear that individual lipid species play different functional roles. However, in comparison with proteins, relatively little is known about how lipids are distributed in the membrane. Several microscopic methods are available to study membrane lipid dynamics in living cells, but defining the distribution of lipids at the submicrometre scale is difficult, because lipids diffuse quickly in the membrane and most lipids do not react with aldehydes that are commonly used as fixatives. Quick-freezing appears to be the only practical method by which to stop the lipid movement instantaneously and capture the molecular localization at the moment of interest. Electron microscopic methods, using cryosections, resin sections, and freeze-fracture replicas are used to visualize lipids in quick-frozen samples. The method that employs the freeze-fracture replica is unique in that it requires no chemical treatment and provides a two-dimensional view of the membrane.
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42
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Lucken-Ardjomande Häsler S, Vallis Y, Jolin HE, McKenzie AN, McMahon HT. GRAF1a is a brain-specific protein that promotes lipid droplet clustering and growth, and is enriched at lipid droplet junctions. J Cell Sci 2014; 127:4602-19. [PMID: 25189622 PMCID: PMC4215711 DOI: 10.1242/jcs.147694] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Lipid droplets are found in all cell types. Normally present at low levels in the brain, they accumulate in tumours and are associated with neurodegenerative diseases. However, little is known about the mechanisms controlling their homeostasis in the brain. We found that GRAF1a, the longest GRAF1 isoform (GRAF1 is also known as ARHGAP26), was enriched in the brains of neonates. Endogenous GRAF1a was found on lipid droplets in oleic-acid-fed primary glial cells. Exclusive localization required a GRAF1a-specific hydrophobic segment and two membrane-binding regions, a BAR and a PH domain. Overexpression of GRAF1a promoted lipid droplet clustering, inhibited droplet mobility and severely perturbed lipolysis following the chase of cells overloaded with fatty acids. Under these conditions, GRAF1a concentrated at the interface between lipid droplets. Although GRAF1-knockout mice did not show any gross abnormal phenotype, the total lipid droplet volume that accumulated in GRAF1(-/-) primary glia upon incubation with fatty acids was reduced compared to GRAF1(+/+) cells. These results provide additional insights into the mechanisms contributing to lipid droplet growth in non-adipocyte cells, and suggest that proteins with membrane sculpting BAR domains play a role in droplet homeostasis.
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Affiliation(s)
| | - Yvonne Vallis
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Helen E Jolin
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Andrew N McKenzie
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Harvey T McMahon
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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43
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Kumar V, Giri SK, Venugopalan P, Kartha KPR. Synthesis of Cross-Linked Glycopeptides and Ureas by a Mechanochemical, Solvent-Free Reaction and Determination of Their Structural Properties by TEM and X-ray Crystallography. Chempluschem 2014. [DOI: 10.1002/cplu.201402185] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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44
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Label-free in vitro visualization and characterization of caveolar bulbs during stimulated re-epithelialization. Anal Bioanal Chem 2014; 406:6993-7002. [DOI: 10.1007/s00216-014-7998-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/19/2014] [Accepted: 06/24/2014] [Indexed: 11/26/2022]
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45
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Küch EM, Vellaramkalayil R, Zhang I, Lehnen D, Brügger B, Sreemmel W, Ehehalt R, Poppelreuther M, Füllekrug J. Differentially localized acyl-CoA synthetase 4 isoenzymes mediate the metabolic channeling of fatty acids towards phosphatidylinositol. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:227-39. [PMID: 24201376 DOI: 10.1016/j.bbalip.2013.10.018] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 09/20/2013] [Accepted: 10/14/2013] [Indexed: 02/06/2023]
Abstract
The acyl-CoA synthetase 4 (ACSL4) has been implicated in carcinogenesis and neuronal development. Acyl-CoA synthetases are essential enzymes of lipid metabolism, and ACSL4 is distinguished by its preference for arachidonic acid. Two human ACSL4 isoforms arising from differential splicing were analyzed by ectopic expression in COS cells. We found that the ACSL4_v1 variant localized to the inner side of the plasma membrane including microvilli, and was also present in the cytosol. ACSL4_v2 contains an additional N-terminal hydrophobic region; this isoform was located at the endoplasmic reticulum and on lipid droplets. A third isoform was designed de novo by appending a mitochondrial targeting signal. All three ACSL4 variants showed the same specific enzyme activity. Overexpression of the isoenzymes increased cellular uptake of arachidonate to the same degree, indicating that the metabolic trapping of fatty acids is independent of the subcellular localization. Remarkably, phospholipid metabolism was changed by ACSL4 expression. Labeling with arachidonate showed that the amount of newly synthesized phosphatidylinositol was increased by all three ACSL4 isoenzymes but not by ACSL1. This was dependent on the expression level and the localization of the ACSL4 isoform. We conclude that in our model system exogenous fatty acids are channeled preferentially towards phosphatidylinositol by ACSL4 overexpression. The differential localization of the endogenous isoenzymes may provide compartment specific precursors of this anionic phospholipid important for many signaling processes.
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46
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Abstract
The liver plays an important role in triacylglycerol (TG) metabolism. It can store large amounts of TG in cytosolic lipid droplets (CLDs), or it can package TG into very-low density lipoproteins (VLDL) that are secreted from the cell. TG packaged into VLDL is derived from TG stored within the endoplasmic reticulum in lumenal lipid droplets (LLDs). Therefore, the liver contains at least three kinds of LDs that differ in their protein composition, subcellular localization, and function. Hepatic LDs undergo tremendous changes in their size and protein composition depending on the energetic (fasting/feeding) and pathological (viral infection, nonalcoholic fatty liver disease, etc.) states. It is crucial to develop methodologies that allow the isolation and analyses of the various hepatic LDs in order to gain insight into the differential metabolism of these important lipid storage/transport particles in health and disease. Here, we present detailed protocols for the isolation and analysis of CLDs and LLDs and for monitoring CLD dynamics.
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47
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Li PF, Wang HL, Qu J. 1,n-Rearrangement of Allylic Alcohols Promoted by Hot Water: Application to the Synthesis of Navenone B, a Polyene Natural Product. J Org Chem 2014; 79:3955-62. [DOI: 10.1021/jo5004086] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Pei-Fang Li
- State Key Laboratory and
Institute of Elemento-organic Chemistry, Collaborative Innovation
Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China
| | - Heng-Lu Wang
- State Key Laboratory and
Institute of Elemento-organic Chemistry, Collaborative Innovation
Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China
| | - Jin Qu
- State Key Laboratory and
Institute of Elemento-organic Chemistry, Collaborative Innovation
Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China
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Vihervaara T, Suoniemi M, Laaksonen R. Lipidomics in drug discovery. Drug Discov Today 2014; 19:164-70. [DOI: 10.1016/j.drudis.2013.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 08/23/2013] [Accepted: 09/10/2013] [Indexed: 12/19/2022]
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Takatori S, Mesman R, Fujimoto T. Microscopic methods to observe the distribution of lipids in the cellular membrane. Biochemistry 2014; 53:639-53. [PMID: 24460209 DOI: 10.1021/bi401598v] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Membrane lipids not only provide the structural framework of cellular membranes but also influence protein functions in several different ways. In comparison to proteins, however, relatively little is known about distribution of membrane lipids because of the insufficiency of microscopic methods. The difficulty in studying lipid distribution results from several factors, including their unresponsiveness to chemical fixation, fast translational movement, small molecular size, and high packing density. In this Current Topic, we consider the major microscopic methods and discuss whether and to what degree of precision these methods can reveal membrane lipid distribution in situ. We highlight two fixation methods, chemical and physical, and compare the theoretical limitations to their spatial resolution. Recognizing the strengths and weaknesses of each method should help researchers interpret their microscopic results and increase our understanding of the physiological functions of lipids.
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Affiliation(s)
- Sho Takatori
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine , Nagoya 466-8550, Japan
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Kuerschner L, Thiele C. Multiple bonds for the lipid interest. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:1031-7. [PMID: 24412758 DOI: 10.1016/j.bbalip.2013.12.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 12/23/2013] [Accepted: 12/26/2013] [Indexed: 10/25/2022]
Abstract
Polyene lipids and alkyne lipids allow study of lipid organization, dynamics and metabolism. Both types of lipids contain multiple bonds as the essential functional group, leading to minimal disturbance of the hydrophobic properties on which the characteristic behavior of lipids is based. Polyene lipids can directly be traced due to their intrinsic fluorescence, while alkyne lipids need the copper-catalyzed click reaction to an azido-reporter for detection. This review describes recent developments in synthesis and application of both types of lipid analogs with emphasis on metabolic tracing and microscopy imaging. This article is part of a Special Issue entitled Tools to study lipid functions.
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Affiliation(s)
- Lars Kuerschner
- Life & Medical Sciences Institute (LIMES), University of Bonn, Carl-Troll-Str. 31, D-53115 Bonn, Germany.
| | - Christoph Thiele
- Life & Medical Sciences Institute (LIMES), University of Bonn, Carl-Troll-Str. 31, D-53115 Bonn, Germany.
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