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Lipid mediators in platelet concentrate and extracellular vesicles: Molecular mechanisms from membrane glycerophospholipids to bioactive molecules. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1168-1182. [DOI: 10.1016/j.bbalip.2019.03.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/15/2019] [Accepted: 03/30/2019] [Indexed: 12/11/2022]
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52
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Jing J, Liu G, Huang Y, Zhou Y. A molecular toolbox for interrogation of membrane contact sites. J Physiol 2019; 598:1725-1739. [PMID: 31119749 PMCID: PMC7098838 DOI: 10.1113/jp277761] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/17/2019] [Indexed: 01/04/2023] Open
Abstract
Membrane contact sites (MCSs) are specialized subcellular compartments formed by closely apposed membranes from two organelles. The intermembrane gap is separated by a distance ranging from 10 to 35 nm. MCSs are typically maintained through dynamic protein–protein and protein–lipid interactions. These intermembrane contact sites constitute important intracellular signalling hotspots to mediate a plethora of cellular processes, including calcium homeostasis, lipid metabolism, membrane biogenesis and organelle remodelling. In recent years, a series of genetically encoded probes and chemogenetic or optogenetic actuators have been invented to aid the visualization and interrogation of MCSs in both fixed and living cells. These molecular tools have greatly accelerated the pace of mechanistic dissection of membrane contact sites at the molecular level. In this review, we present an overview on the latest progress in this endeavour, and provide a general guide to the selection of methods and molecular tools for probing interorganellar membrane contact sites.
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Affiliation(s)
- Ji Jing
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX, 77030, USA
| | - Gan Liu
- Cockrell School of Engineering, University of Texas, Austin, TX, 78712, USA
| | - Yun Huang
- Center for Epigenetics and Disease Prevention, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX, 77030, USA
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, TX, 77030, USA
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53
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Jha A, Chung WY, Vachel L, Maleth J, Lake S, Zhang G, Ahuja M, Muallem S. Anoctamin 8 tethers endoplasmic reticulum and plasma membrane for assembly of Ca 2+ signaling complexes at the ER/PM compartment. EMBO J 2019; 38:embj.2018101452. [PMID: 31061173 DOI: 10.15252/embj.2018101452] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 04/03/2019] [Accepted: 04/05/2019] [Indexed: 12/18/2022] Open
Abstract
Communication and material transfer between membranes and organelles take place at membrane contact sites (MCSs). MCSs between the ER and PM, the ER/PM junctions, are the sites where the ER Ca2+ sensor STIM1 and the PM Ca2+ influx channel Orai1 cluster. MCSs are formed by tether proteins that bridge the opposing membranes, but the identity and role of these tethers in receptor-evoked Ca2+ signaling is not well understood. Here, we identified Anoctamin 8 (ANO8) as a key tether in the formation of the ER/PM junctions that is essential for STIM1-STIM1 interaction and STIM1-Orai1 interaction and channel activation at a ER/PM PI(4,5)P2-rich compartment. Moreover, ANO8 assembles all core Ca2+ signaling proteins: Orai1, PMCA, STIM1, IP3 receptors, and SERCA2 at the ER/PM junctions to mediate a novel form of Orai1 channel inactivation by markedly facilitating SERCA2-mediated Ca2+ influx into the ER. This controls the efficiency of receptor-stimulated Ca2+ signaling, Ca2+ oscillations, and duration of Orai1 activity to prevent Ca2+ toxicity. These findings reveal the central role of MCSs in determining efficiency and fidelity of cell signaling.
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Affiliation(s)
- Archana Jha
- The Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Woo Young Chung
- The Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Laura Vachel
- The Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Jozsef Maleth
- First Department of Medicine, University of Szeged, Szeged, Hungary
| | - Sarah Lake
- The Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Guofeng Zhang
- Trans-NIH Shared Resource on Biomedical Engineering and Physical Science (BEPS) National Institute of Biomedical Imaging & Bioengineering, Bethesda, MD, USA
| | - Malini Ahuja
- The Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Shmuel Muallem
- The Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
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54
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Funato K, Riezman H, Muñiz M. Vesicular and non-vesicular lipid export from the ER to the secretory pathway. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158453. [PMID: 31054928 DOI: 10.1016/j.bbalip.2019.04.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 11/26/2022]
Abstract
The endoplasmic reticulum is the site of synthesis of most glycerophospholipids, neutral lipids and the initial steps of sphingolipid biosynthesis of the secretory pathway. After synthesis, these lipids are distributed within the cells to create and maintain the specific compositions of the other secretory organelles. This represents a formidable challenge, particularly while there is a simultaneous and quantitatively important flux of membrane components stemming from the vesicular traffic of proteins through the pathway, which can also vary depending on the cell type and status. To meet this challenge cells have developed an intricate system of interorganellar contacts and lipid transport proteins, functioning in non-vesicular lipid transport, which are able to ensure membrane lipid homeostasis even in the absence of membrane trafficking. Nevertheless, under normal conditions, lipids are transported in cells by both vesicular and non-vesicular mechanisms. In this review we will discuss the mechanism and roles of vesicular and non-vesicular transport of lipids from the ER to other organelles of the secretory pathway.
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Affiliation(s)
- Kouichi Funato
- Department of Bioresource Science and Technology, Hiroshima University, Japan.
| | - Howard Riezman
- NCCR Chemical Biology and Department of Biochemistry, Sciences II, University of Geneva, Switzerland.
| | - Manuel Muñiz
- Department of Cell Biology, University of Seville, 41012 Seville, Spain; Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain.
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55
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Dakik P, Medkour Y, Mohammad K, Titorenko VI. Mechanisms Through Which Some Mitochondria-Generated Metabolites Act as Second Messengers That Are Essential Contributors to the Aging Process in Eukaryotes Across Phyla. Front Physiol 2019; 10:461. [PMID: 31057428 PMCID: PMC6482166 DOI: 10.3389/fphys.2019.00461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/02/2019] [Indexed: 12/21/2022] Open
Abstract
Recent studies have revealed that some low-molecular weight molecules produced in mitochondria are essential contributing factors to aging and aging-associated pathologies in evolutionarily distant eukaryotes. These molecules are intermediates or products of certain metabolic reactions that are activated in mitochondria in response to specific changes in the nutrient, stress, proliferation, or age status of the cell. After being released from mitochondria, these metabolites directly or indirectly change activities of a distinct set of protein sensors that reside in various cellular locations outside of mitochondria. Because these protein sensors control the efficiencies of some pro- or anti-aging cellular processes, such changes in their activities allow to create a pro- or anti-aging cellular pattern. Thus, mitochondria can function as signaling platforms that respond to certain changes in cell stress and physiology by remodeling their metabolism and releasing a specific set of metabolites known as "mitobolites." These mitobolites then define the pace of cellular and organismal aging because they regulate some longevity-defining processes taking place outside of mitochondria. In this review, we discuss recent progress in understanding mechanisms underlying the ability of mitochondria to function as such signaling platforms in aging and aging-associated diseases.
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56
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Cirigliano A, Macone A, Bianchi MM, Oliaro-Bosso S, Balliano G, Negri R, Rinaldi T. Ergosterol reduction impairs mitochondrial DNA maintenance in S. cerevisiae. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:290-303. [DOI: 10.1016/j.bbalip.2018.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 11/27/2018] [Accepted: 12/10/2018] [Indexed: 12/20/2022]
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57
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Petit JD, Immel F, Lins L, Bayer EM. Lipids or Proteins: Who Is Leading the Dance at Membrane Contact Sites? FRONTIERS IN PLANT SCIENCE 2019; 10:198. [PMID: 30846999 PMCID: PMC6393330 DOI: 10.3389/fpls.2019.00198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/05/2019] [Indexed: 05/19/2023]
Abstract
Understanding the mode of action of membrane contact sites (MCSs) across eukaryotic organisms at the near-atomic level to infer function at the cellular and tissue levels is a challenge scientists are currently facing. These peculiar systems dedicated to inter-organellar communication are perfect examples of cellular processes where the interplay between lipids and proteins is critical. In this mini review, we underline the link between membrane lipid environment, the recruitment of proteins at specialized membrane domains and the function of MCSs. More precisely, we want to give insights on the crucial role of lipids in defining the specificity of plant endoplasmic reticulum (ER)-plasma membrane (PM) MCSs and we further propose approaches to study them at multiple scales. Our goal is not so much to go into detailed description of MCSs, as there are numerous focused reviews on the subject, but rather try to pinpoint the critical elements defining those structures and give an original point of view by considering the subject from a near-atomic angle with a focus on lipids. We review current knowledge as to how lipids can define MCS territories, play a role in the recruitment and function of the MCS-associated proteins and in turn, how the lipid environment can be modified by proteins.
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Affiliation(s)
- Jules D. Petit
- UMR5200 CNRS, Laboratory of Membrane Biogenesis, University of Bordeaux, Villenave d’Ornon, France
- Laboratoire de Biophysique Moléculaire aux Interfaces, TERRA Research Centre, GX ABT, Université de Liège, Liège, Belgium
| | - Françoise Immel
- UMR5200 CNRS, Laboratory of Membrane Biogenesis, University of Bordeaux, Villenave d’Ornon, France
| | - Laurence Lins
- Laboratoire de Biophysique Moléculaire aux Interfaces, TERRA Research Centre, GX ABT, Université de Liège, Liège, Belgium
| | - Emmanuelle M. Bayer
- UMR5200 CNRS, Laboratory of Membrane Biogenesis, University of Bordeaux, Villenave d’Ornon, France
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58
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Cerminati S, Paoletti L, Aguirre A, Peirú S, Menzella HG, Castelli ME. Industrial uses of phospholipases: current state and future applications. Appl Microbiol Biotechnol 2019; 103:2571-2582. [DOI: 10.1007/s00253-019-09658-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/18/2019] [Accepted: 01/23/2019] [Indexed: 12/18/2022]
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59
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Fritsch J, Tchikov V, Hennig L, Lucius R, Schütze S. A toolbox for the immunomagnetic purification of signaling organelles. Traffic 2019; 20:246-258. [PMID: 30569578 DOI: 10.1111/tra.12631] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 12/18/2018] [Accepted: 12/18/2018] [Indexed: 12/19/2022]
Abstract
Homeostasis and the complex functions of organisms and cells rely on the sophisticated spatial and temporal regulation of signaling in different intra- and extracellular compartments and via different mediators. We here present a set of fast and easy to use protocols for the target-specific immunomagnetic enrichment of receptor containing endosomes (receptosomes), plasma membranes, lysosomes and exosomes. Isolation of subcellular organelles and exosomes is prerequisite for and will advance their detailed subsequent biochemical and functional analysis. Sequential application of the different subprotocols allows isolation of morphological and functional intact organelles from one pool of cells. The enrichment is based on a selective labelling using receptor ligands or antibodies together with superparamagnetic microbeads followed by separation in a patented matrix-free high-gradient magnetic purification device. This unique magnetic chamber is based on a focusing system outside of the empty separation column, generating an up to 3 T high-gradient magnetic field focused at the wall of the column.
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Affiliation(s)
- Jürgen Fritsch
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany.,Institute for Clinical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany
| | - Vladimir Tchikov
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Lena Hennig
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Ralph Lucius
- Institute of Anatomy, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Stefan Schütze
- Institute of Immunology, Christian-Albrechts-University of Kiel, Kiel, Germany
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60
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Research Progress on the Relationship Between Acute Pancreatitis and Calcium Overload in Acinar Cells. Dig Dis Sci 2019; 64:25-38. [PMID: 30284136 DOI: 10.1007/s10620-018-5297-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 09/01/2018] [Indexed: 02/07/2023]
Abstract
Acute pancreatitis is a human disease with multiple causes that leads to autodigestion of the pancreas. There is sufficient evidence to support the key role of sustained increase in cytosolic calcium concentrations in the early pathogenesis of the disease. To clarify the mechanism of maintaining calcium homeostasis in the cell and pathological processes caused by calcium overload would help to research directly targeted therapeutic agents. We will specifically review the following: intracellular calcium homeostasis and regulation, the occurrence of calcium overload in acinar cells, the role of calcium overload in the pathogenesis of AP, the treatment strategy proposed for calcium overload.
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61
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Pemberton JG, Balla T. Polyphosphoinositide-Binding Domains: Insights from Peripheral Membrane and Lipid-Transfer Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1111:77-137. [PMID: 30483964 DOI: 10.1007/5584_2018_288] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Within eukaryotic cells, biochemical reactions need to be organized on the surface of membrane compartments that use distinct lipid constituents to dynamically modulate the functions of integral proteins or influence the selective recruitment of peripheral membrane effectors. As a result of these complex interactions, a variety of human pathologies can be traced back to improper communication between proteins and membrane surfaces; either due to mutations that directly alter protein structure or as a result of changes in membrane lipid composition. Among the known structural lipids found in cellular membranes, phosphatidylinositol (PtdIns) is unique in that it also serves as the membrane-anchored precursor of low-abundance regulatory lipids, the polyphosphoinositides (PPIn), which have restricted distributions within specific subcellular compartments. The ability of PPIn lipids to function as signaling platforms relies on both non-specific electrostatic interactions and the selective stereospecific recognition of PPIn headgroups by specialized protein folds. In this chapter, we will attempt to summarize the structural diversity of modular PPIn-interacting domains that facilitate the reversible recruitment and conformational regulation of peripheral membrane proteins. Outside of protein folds capable of capturing PPIn headgroups at the membrane interface, recent studies detailing the selective binding and bilayer extraction of PPIn species by unique functional domains within specific families of lipid-transfer proteins will also be highlighted. Overall, this overview will help to outline the fundamental physiochemical mechanisms that facilitate localized interactions between PPIn lipids and the wide-variety of PPIn-binding proteins that are essential for the coordinate regulation of cellular metabolism and membrane dynamics.
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Affiliation(s)
- Joshua G Pemberton
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Tamas Balla
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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62
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Liu H, Kabrah A, Ahuja M, Muallem S. CRAC channels in secretory epithelial cell function and disease. Cell Calcium 2018; 78:48-55. [PMID: 30641249 DOI: 10.1016/j.ceca.2018.12.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/28/2018] [Accepted: 12/29/2018] [Indexed: 02/08/2023]
Abstract
The receptor-evoked Ca2+ signal in secretory epithelia mediate many cellular functions essential for cell survival and their most fundamental functions of secretory granules exocytosis and fluid and electrolyte secretion. Ca2+ influx is a key component of the receptor-evoked Ca2+ signal in secretory cell and is mediated by both TRPC and the STIM1-activated Orai1 channels that mediates the Ca2+ release-activated current (CRAC) Icrac. The core components of the receptor-evoked Ca2+ signal are assembled at the ER/PM junctions where exchange of materials between the plasma membrane and internal organelles take place, including transfer of lipids and Ca2+. The Ca2+ signal generated at the confined space of the ER/PM junctions is necessary for activation of the Ca2+-regulated proteins and ion channels that mediate exocytosis with high fidelity and tight control. In this review we discuss the general properties of Ca2+ signaling, PI(4,5)P2 and other lipids at the ER/PM junctions with regard to secretory cells function and disease caused by uncontrolled Ca2+ influx.
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Affiliation(s)
- Haiping Liu
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Ahmed Kabrah
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, 20892, United States.
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63
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Leopold J, Popkova Y, Engel KM, Schiller J. Recent Developments of Useful MALDI Matrices for the Mass Spectrometric Characterization of Lipids. Biomolecules 2018; 8:biom8040173. [PMID: 30551655 PMCID: PMC6316665 DOI: 10.3390/biom8040173] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/06/2018] [Accepted: 12/10/2018] [Indexed: 12/24/2022] Open
Abstract
Matrix-assisted laser desorption/ionization (MALDI) is one of the most successful “soft” ionization methods in the field of mass spectrometry and enables the analysis of a broad range of molecules, including lipids. Although the details of the ionization process are still unknown, the importance of the matrix is commonly accepted. Both, the development of and the search for useful matrices was, and still is, an empirical process, since properties like vacuum stability, high absorption at the laser wavelength, etc. have to be fulfilled by a compound to become a useful matrix. This review provides a survey of successfully used MALDI matrices for the lipid analyses of complex biological samples. The advantages and drawbacks of the established organic matrix molecules (cinnamic or benzoic acid derivatives), liquid crystalline matrices, and mixtures of common matrices will be discussed. Furthermore, we will deal with nanocrystalline matrices, which are most suitable to analyze small molecules, such as free fatty acids. It will be shown that the analysis of mixtures and the quantitative analysis of small molecules can be easily performed if the matrix is carefully selected. Finally, some basic principles of how useful matrix compounds can be “designed” de novo will be introduced.
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Affiliation(s)
- Jenny Leopold
- Faculty of Medicine, Institute for Medical Physics and Biophysics, Härtelstr. 16/18, Leipzig University, D-04107 Leipzig, Germany.
| | - Yulia Popkova
- Faculty of Medicine, Institute for Medical Physics and Biophysics, Härtelstr. 16/18, Leipzig University, D-04107 Leipzig, Germany.
| | - Kathrin M Engel
- Faculty of Medicine, Institute for Medical Physics and Biophysics, Härtelstr. 16/18, Leipzig University, D-04107 Leipzig, Germany.
| | - Jürgen Schiller
- Faculty of Medicine, Institute for Medical Physics and Biophysics, Härtelstr. 16/18, Leipzig University, D-04107 Leipzig, Germany.
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64
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Wang S, Allen N, Liang XH, Crooke ST. Membrane Destabilization Induced by Lipid Species Increases Activity of Phosphorothioate-Antisense Oligonucleotides. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 13:686-698. [PMID: 30508785 PMCID: PMC6276310 DOI: 10.1016/j.omtn.2018.10.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 10/16/2018] [Accepted: 10/17/2018] [Indexed: 01/03/2023]
Abstract
Chemically modified antisense oligonucleotides with phosphorothioate linkages (PS-ASOs) mediate site-specific cleavage of RNA by RNase H1 and are broadly used as research and therapeutic tools. PS-ASOs can enter cells via endocytic pathways and escape from membrane-enclosed endocytic organelles to reach target RNAs. We recently found that lysobisphosphatidic acid is required for release of PS-ASOs from late endosomes. Here, we evaluated the effects of other lipids on PS-ASO intracellular trafficking and activities. We show that free fatty acids, ceramide, and cholesterol increase PS-ASO activities. Free fatty acids induced formation of lipid droplets without changing the intracellular localization of PS-ASOs in early or late endosomes. Ceramide and cholesterol did not obviously induce the formation of lipid droplets, but cholesterol caused enlargement of endosome size and volume. Although none of those lipids appeared to influence PS-ASO internalization or intracellular trafficking processes, all led to an increase in leakiness of late endosomes. Thus, the membrane destabilization induced by these lipids likely contributes to PS-ASO release from late endosomes, which, in turn, increases PS-ASO activity.
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Affiliation(s)
- Shiyu Wang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA.
| | - Nickolas Allen
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Xue-Hai Liang
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Stanley T Crooke
- Department of Core Antisense Research, Ionis Pharmaceuticals, Inc., 2855 Gazelle Court, Carlsbad, CA 92010, USA
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65
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Pulli I, Lassila T, Pan G, Yan D, Olkkonen VM, Törnquist K. Oxysterol-binding protein related-proteins (ORPs) 5 and 8 regulate calcium signaling at specific cell compartments. Cell Calcium 2018; 72:62-69. [PMID: 29748134 DOI: 10.1016/j.ceca.2018.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 03/02/2018] [Accepted: 03/12/2018] [Indexed: 12/24/2022]
Abstract
Oxysterol-binding protein related-protein 5 and 8 (ORP5/8) localize to the membrane contact sites (MCS) of the endoplasmic reticulum (ER) and the mitochondria, as well as to the ER-plasma membrane (PM) MCS. The MCS are emerging as important regulators of cell signaling events, including calcium (Ca2+) signaling. ORP5/8 have been shown to interact with phosphatidylinositol-4,5-bisphosphate (PIP2) in the PM, and to modulate mitochondrial respiration and morphology. PIP2 is the direct precursor of inositol trisphosphate (IP3), a key second messenger responsible for Ca2+-release from the intracellular Ca2+ stores. Further, mitochondrial respiration is linked to Ca2+ transfer from the ER to the mitochondria. Hence, we asked whether ORP5/8 would affect Ca2+ signaling in these cell compartments, and employed genetically engineered aequorin Ca2+ probes to investigate the effect of ORP5/8 in the regulation of mitochondrial and caveolar Ca2+. Our results show that ORP5/8 overexpression leads to increased mitochondrial matrix Ca2+ as well as to increased Ca2+ concentration at the caveolar subdomains of the PM during histamine stimulation, while having no effect on the cytoplasmic Ca2+. Also, we found that ORP5/8 overexpression increases cell proliferation. Our results show that ORP5/8 regulate Ca2+ signaling at specific MCS foci. These local ORP5/8-mediated Ca2+ signaling events are likely to play roles in processes such as mitochondrial respiration and cell proliferation.
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Affiliation(s)
- Ilari Pulli
- Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland
| | - Taru Lassila
- Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland
| | - Guoping Pan
- The Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Department of Biotechnology, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Daoguang Yan
- The Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Department of Biotechnology, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Vesa M Olkkonen
- Minerva Foundation Institute For Medical Research, Biomedicum Helsinki, 00290 Helsinki, Finland; Department of Anatomy, Faculty of Medicine, FI-00014 University of Helsinki, Finland
| | - Kid Törnquist
- Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland; Minerva Foundation Institute For Medical Research, Biomedicum Helsinki, 00290 Helsinki, Finland.
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66
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Muallem S, Chung WY, Jha A, Ahuja M. Lipids at membrane contact sites: cell signaling and ion transport. EMBO Rep 2017; 18:1893-1904. [PMID: 29030479 DOI: 10.15252/embr.201744331] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/10/2017] [Accepted: 09/21/2017] [Indexed: 12/14/2022] Open
Abstract
Communication between organelles is essential to coordinate cellular functions and the cell's response to physiological and pathological stimuli. Organellar communication occurs at membrane contact sites (MCSs), where the endoplasmic reticulum (ER) membrane is tethered to cellular organelle membranes by specific tether proteins and where lipid transfer proteins and cell signaling proteins are located. MCSs have many cellular functions and are the sites of lipid and ion transfer between organelles and generation of second messengers. This review discusses several aspects of MCSs in the context of lipid transfer, formation of lipid domains, generation of Ca2+ and cAMP second messengers, and regulation of ion transporters by lipids.
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Affiliation(s)
- Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Woo Young Chung
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Archana Jha
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
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