1
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Fang XX, Wei P, Zhao K, Sheng ZC, Song BL, Yin L, Luo J. Fatty acid-binding proteins 3, 7, and 8 bind cholesterol and facilitate its egress from lysosomes. J Cell Biol 2024; 223:e202211062. [PMID: 38429999 PMCID: PMC10909654 DOI: 10.1083/jcb.202211062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 03/22/2023] [Accepted: 01/18/2024] [Indexed: 03/03/2024] Open
Abstract
Cholesterol from low-density lipoprotein (LDL) can be transported to many organelle membranes by non-vesicular mechanisms involving sterol transfer proteins (STPs). Fatty acid-binding protein (FABP) 7 was identified in our previous study searching for new regulators of intracellular cholesterol trafficking. Whether FABP7 is a bona fide STP remains unknown. Here, we found that FABP7 deficiency resulted in the accumulation of LDL-derived cholesterol in lysosomes and reduced cholesterol levels on the plasma membrane. A crystal structure of human FABP7 protein in complex with cholesterol was resolved at 2.7 Å resolution. In vitro, FABP7 efficiently transported the cholesterol analog dehydroergosterol between the liposomes. Further, the silencing of FABP3 and 8, which belong to the same family as FABP7, caused robust cholesterol accumulation in lysosomes. These two FABP proteins could transport dehydroergosterol in vitro as well. Collectively, our results suggest that FABP3, 7, and 8 are a new class of STPs mediating cholesterol egress from lysosomes.
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Affiliation(s)
- Xian-Xiu Fang
- The Institute for Advanced Studies, College of Life Sciences, Hubei Key Laboratory of Cell Homeostasis, Taikang Center for Life and Medical Sciences, Taikang Medical School, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Pengcheng Wei
- The Institute for Advanced Studies, College of Life Sciences, Hubei Key Laboratory of Cell Homeostasis, Taikang Center for Life and Medical Sciences, Taikang Medical School, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Kai Zhao
- The Institute for Advanced Studies, College of Life Sciences, Hubei Key Laboratory of Cell Homeostasis, Taikang Center for Life and Medical Sciences, Taikang Medical School, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Zhao-Chen Sheng
- The Institute for Advanced Studies, College of Life Sciences, Hubei Key Laboratory of Cell Homeostasis, Taikang Center for Life and Medical Sciences, Taikang Medical School, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Bao-Liang Song
- The Institute for Advanced Studies, College of Life Sciences, Hubei Key Laboratory of Cell Homeostasis, Taikang Center for Life and Medical Sciences, Taikang Medical School, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Lei Yin
- The Institute for Advanced Studies, College of Life Sciences, Hubei Key Laboratory of Cell Homeostasis, Taikang Center for Life and Medical Sciences, Taikang Medical School, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
| | - Jie Luo
- The Institute for Advanced Studies, College of Life Sciences, Hubei Key Laboratory of Cell Homeostasis, Taikang Center for Life and Medical Sciences, Taikang Medical School, Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, China
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2
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Chen J, Tieleman DP, Liang Q. Effects of Lid Domain Structural Changes on the Interactions between Peripheral Myelin Protein 2 and a Lipid Bilayer. J Phys Chem Lett 2022; 13:991-996. [PMID: 35060724 DOI: 10.1021/acs.jpclett.1c03961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Peripheral myelin protein 2 (P2) plays an important role in the stacking of the myelin membrane and lipid transport. Here we investigate the interactions between P2 and a model myelin membrane using molecular dynamics simulations, focusing on the effect of the L27D mutation and conformational changes in the α2-helix in the lid domain of P2. The L27D mutation weakens the binding of the lid domain of P2 on the membrane. The α2-helix is either folded or unfolded on the membrane. Compared with the α2-helix structure in water, the membrane stabilizes the structure of the α2-helix, whereas the unfolding of the α2-helix reduces the binding affinity of P2 on the membrane. These findings reveal the energetics of the mutant and the structural changes of P2 on the interactions between the protein and the lipid bilayer and help us to understand the microscopic mechanism of the formation of the myelin sheath structure and some neurological disorders.
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Affiliation(s)
- Jinyu Chen
- Center for Statistical and Theoretical Condensed Matter Physics and Department of Physics, Zhejiang Normal University, Jinhua 321004, P. R. China
| | - D Peter Tieleman
- Centre for Molecular Simulations and Department of Biological Science, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Qing Liang
- Center for Statistical and Theoretical Condensed Matter Physics and Department of Physics, Zhejiang Normal University, Jinhua 321004, P. R. China
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3
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Abe M, Makino A, Murate M, Hullin-Matsuda F, Yanagawa M, Sako Y, Kobayashi T. PMP2/FABP8 induces PI(4,5)P 2-dependent transbilayer reorganization of sphingomyelin in the plasma membrane. Cell Rep 2021; 37:109935. [PMID: 34758297 DOI: 10.1016/j.celrep.2021.109935] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 08/20/2021] [Accepted: 10/13/2021] [Indexed: 12/11/2022] Open
Abstract
Sphingomyelin (SM) is a mammalian lipid mainly distributed in the outer leaflet of the plasma membrane (PM). We show that peripheral myelin protein 2 (PMP2), a member of the fatty-acid-binding protein (FABP) family, can localize at the PM and controls the transbilayer distribution of SM. Genetic screening with genome-wide small hairpin RNA libraries identifies PMP2 as a protein involved in the transbilayer movement of SM. A biochemical assay demonstrates that PMP2 is a phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-binding protein. PMP2 induces the tubulation of model membranes in a PI(4,5)P2-dependent manner, accompanied by the modification of the transbilayer membrane distribution of lipids. In the PM of PMP2-overexpressing cells, inner-leaflet SM is increased whereas outer-leaflet SM is reduced. PMP2 is a causative protein of Charcot-Marie-Tooth disease (CMT). A mutation in PMP2 associated with CMT increases its affinity for PI(4,5)P2, inducing membrane tubulation and the subsequent transbilayer movement of lipids.
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Affiliation(s)
- Mitsuhiro Abe
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
| | - Asami Makino
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Motohide Murate
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
| | - Françoise Hullin-Matsuda
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Université de Lyon, CarMeN Laboratory, INSERM U1060, INRAE U1397, Université Claude Bernard Lyon 1, 69495 Pierre-Benite, France
| | - Masataka Yanagawa
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Toshihide Kobayashi
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France.
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4
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Nam KH. Crystal structure of human brain-type fatty acid-binding protein FABP7 complexed with palmitic acid. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2021; 77:954-965. [PMID: 34196621 DOI: 10.1107/s2059798321005763] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/03/2021] [Indexed: 11/11/2022]
Abstract
The brain-type fatty acid-binding protein FABP7, which is expressed in astrocytes and neural progenitors, is a member of the intracellular lipid-binding protein family. This protein is not only involved in various cellular functions such as metabolism, inflammation and energy homeostasis, but also in diseases such as cognitive disorders and tumors. Structures of unsaturated fatty acids, such as oleic acid (OA) and docosahexaenoic acid (DHA), bound to FABP7 have been elucidated; however, structures of saturated fatty acids bound to FABP7 remain unknown. To better understand fatty acid recognition, here the crystal structure of human brain-type fatty acid-binding protein FABP7 complexed with palmitic acid (PA), a saturated fatty acid, is reported at a resolution of 1.6 Å. The PA bound to the fatty acid-binding pocket of FABP7 assumed a U-shaped conformation. The carboxylate moiety of PA interacted with Tyr129, Arg127 and, via a water bridge, with Arg107 and Thr54, whereas its aliphatic chain was stabilized by hydrophobic interactions with Met21, Leu24, Thr30, Thr37, Pro39, Phe58 and Asp77. Structural comparison showed that PA, OA and DHA exhibited unique binding conformations in the fatty acid-binding pocket, stabilized by distinct amino-acid interactions. The binding of PA to FABP7 exhibits a unique binding conformation when compared with other human FABPs (FABP3-FABP5 and FABP8) expressed in other tissues. Based on the crystal and fatty acid structures, it was suggested that PA, which prefers a linear form in nature, required a greater conformational change in its aliphatic chain to bind to the fatty acid-binding pocket in a U-shaped conformation, compared with the cis configurations of OA or DHA. This, together with the length of the aliphatic chain, was considered to be one of the factors determining the binding affinity of PA to FABP7. These results provide a better understanding of fatty acid recognition by FABP7 and expand the knowledge of the binding of PA to FABPs.
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Affiliation(s)
- Ki Hyun Nam
- Department of Life Science, Pohang University of Science and Technology, Pohang, Republic of Korea
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5
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Uusitalo M, Klenow MB, Laulumaa S, Blakeley MP, Simonsen AC, Ruskamo S, Kursula P. Human myelin protein P2: from crystallography to time-lapse membrane imaging and neuropathy-associated variants. FEBS J 2021; 288:6716-6735. [PMID: 34138518 DOI: 10.1111/febs.16079] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/10/2021] [Accepted: 06/16/2021] [Indexed: 12/11/2022]
Abstract
Peripheral myelin protein 2 (P2) is a fatty acid-binding protein expressed in vertebrate peripheral nervous system myelin, as well as in human astrocytes. Suggested functions of P2 include membrane stacking and lipid transport. Mutations in the PMP2 gene, encoding P2, are associated with Charcot-Marie-Tooth disease (CMT). Recent studies have revealed three novel PMP2 mutations in CMT patients. To shed light on the structure and function of these P2 variants, we used X-ray and neutron crystallography, small-angle X-ray scattering, circular dichroism spectroscopy, computer simulations and lipid binding assays. The crystal and solution structures of the I50del, M114T and V115A variants of P2 showed minor differences to the wild-type protein, whereas their thermal stability was reduced. Vesicle aggregation assays revealed no change in membrane stacking characteristics, while the variants showed altered fatty acid binding. Time-lapse imaging of lipid bilayers indicated formation of double-membrane structures induced by P2, which could be related to its function in stacking of two myelin membrane surfaces in vivo. In order to better understand the links between structure, dynamics and function, the crystal structure of perdeuterated P2 was refined from room temperature data using neutrons and X-rays, and the results were compared to simulations and cryocooled crystal structures. Our data indicate similar properties for all known human P2 CMT variants; while crystal structures are nearly identical, thermal stability and function of CMT variants are impaired. Our data provide new insights into the structure-function relationships and dynamics of P2 in health and disease.
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Affiliation(s)
- Maiju Uusitalo
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland
| | - Martin Berg Klenow
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Saara Laulumaa
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland.,European Spallation Source, Lund, Sweden
| | | | - Adam Cohen Simonsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Salla Ruskamo
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland.,Department of Biomedicine, University of Bergen, Norway
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6
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Jiang Y, Zhao X, Yu J, Wang Q, Wen C, Huang L. Deciphering potential pharmacological mechanism of Sha-Shen-Mai-Dong decoction on primary Sjogren's syndrome. BMC Complement Med Ther 2021; 21:79. [PMID: 33648502 PMCID: PMC7923330 DOI: 10.1186/s12906-021-03257-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 02/22/2021] [Indexed: 12/29/2022] Open
Abstract
Background Sha-Shen-Mai-Dong decoction (SSMD) is a classical prescription widely used in primary Sjogren’s Syndrome (pSS) therapy. This study aims to explore the potential pharmacological mechanism of SSMD on pSS. Methods Active components of SSMD were obtained from Traditional Chinese Medicine Integrative Database and Traditional Chinese Medicine Systems Pharmacology databases and targets of SSMD were predicted by Pharmmapper and STITCH database. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were carried out to explore the function characteristics of SSMD. The expression matrix of microarray of pSS was obtained from Gene Expression Omnibus and we obtained 162 differentially expressed genes (DEGs). Protein-protein interaction (PPI) networks were constructed to identify the hub targets. Principal component analysis (PCA) and molecular docking were conducted to further elucidate the possibility of SSMD for pSS. Results SSMD contained a total of 1056 active components, corresponding to 88 targets, among which peripheral myelin protein 2(PMP2), androgen receptor (AR) and glutamic acid decarboxylase 1(GAD1) are associated with multiple active components in SSMD and may be the core targets. Moreover, these targets were closely related to tissue pathological injury in SS, such as lacrimal gland, salivary gland and nervous system injury. GO and KEGG analysis showed that 88 targets enriched in REDOX process, transcriptional regulation and negative regulation of apoptosis process. Besides, SSMD may influence the cell proliferation, gene transcription through regulating Ras and cAMP-related signaling pathways. In addition, SSMD may show effects on immune regulation, such as macrophage differentiation, Toll-like receptor 4 signaling pathway and T-helper 1 in SS. Moreover, PPI network suggested that FN1, MMP-9 may be the hub targets in SSMD. Result of PCA and molecular docking analysis further determined the feasibility of SSMD in treating pSS. Conclusion SSMD can regulate multiple biological processes by virtue of its multiple active components, thus showing prominent advantage in the treatment of pSS. The discovery of active ingredients and targets in SSMD provides valuable resources for drug research and development for pSS. Supplementary Information The online version contains supplementary material available at 10.1186/s12906-021-03257-7.
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Affiliation(s)
- Yuepeng Jiang
- College of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310058, China
| | - Xiaoxuan Zhao
- Heilongjiang University of Chinese Medicine, Harbin, 150040, China
| | - Jie Yu
- College of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310058, China
| | - Qiao Wang
- College of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310058, China
| | - Chengping Wen
- College of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310058, China.
| | - Lin Huang
- College of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310058, China.
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7
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How Does Protein Zero Assemble Compact Myelin? Cells 2020; 9:cells9081832. [PMID: 32759708 PMCID: PMC7465998 DOI: 10.3390/cells9081832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/21/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023] Open
Abstract
Myelin protein zero (P0), a type I transmembrane protein, is the most abundant protein in peripheral nervous system (PNS) myelin—the lipid-rich, periodic structure of membrane pairs that concentrically encloses long axonal segments. Schwann cells, the myelinating glia of the PNS, express P0 throughout their development until the formation of mature myelin. In the intramyelinic compartment, the immunoglobulin-like domain of P0 bridges apposing membranes via homophilic adhesion, forming, as revealed by electron microscopy, the electron-dense, double “intraperiod line” that is split by a narrow, electron-lucent space corresponding to the extracellular space between membrane pairs. The C-terminal tail of P0 adheres apposing membranes together in the narrow cytoplasmic compartment of compact myelin, much like myelin basic protein (MBP). In mouse models, the absence of P0, unlike that of MBP or P2, severely disturbs myelination. Therefore, P0 is the executive molecule of PNS myelin maturation. How and when P0 is trafficked and modified to enable myelin compaction, and how mutations that give rise to incurable peripheral neuropathies alter the function of P0, are currently open questions. The potential mechanisms of P0 function in myelination are discussed, providing a foundation for the understanding of mature myelin development and how it derails in peripheral neuropathies.
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8
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Ruskamo S, Krokengen OC, Kowal J, Nieminen T, Lehtimäki M, Raasakka A, Dandey VP, Vattulainen I, Stahlberg H, Kursula P. Cryo-EM, X-ray diffraction, and atomistic simulations reveal determinants for the formation of a supramolecular myelin-like proteolipid lattice. J Biol Chem 2020; 295:8692-8705. [PMID: 32265298 DOI: 10.1074/jbc.ra120.013087] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/31/2020] [Indexed: 12/15/2022] Open
Abstract
Myelin protein P2 is a peripheral membrane protein of the fatty acid-binding protein family that functions in the formation and maintenance of the peripheral nerve myelin sheath. Several P2 gene mutations cause human Charcot-Marie-Tooth neuropathy, but the mature myelin sheath assembly mechanism is unclear. Here, cryo-EM of myelin-like proteolipid multilayers revealed an ordered three-dimensional (3D) lattice of P2 molecules between stacked lipid bilayers, visualizing supramolecular assembly at the myelin major dense line. The data disclosed that a single P2 layer is inserted between two bilayers in a tight intermembrane space of ∼3 nm, implying direct interactions between P2 and two membrane surfaces. X-ray diffraction from P2-stacked bicelle multilayers revealed lateral protein organization, and surface mutagenesis of P2 coupled with structure-function experiments revealed a role for both the portal region of P2 and its opposite face in membrane interactions. Atomistic molecular dynamics simulations of P2 on model membrane surfaces suggested that Arg-88 is critical for P2-membrane interactions, in addition to the helical lid domain. Negatively charged lipid headgroups stably anchored P2 on the myelin-like bilayer surface. Membrane binding may be accompanied by opening of the P2 β-barrel structure and ligand exchange with the apposing bilayer. Our results provide an unprecedented view into an ordered, multilayered biomolecular membrane system induced by the presence of a peripheral membrane protein from human myelin. This is an important step toward deciphering the 3D assembly of a mature myelin sheath at the molecular level.
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Affiliation(s)
- Salla Ruskamo
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90014 Oulu, Finland; Biocenter Oulu, University of Oulu, 90014 Oulu, Finland
| | - Oda C Krokengen
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway
| | - Julia Kowal
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, 4058 Basel, Switzerland
| | - Tuomo Nieminen
- Computational Physics Laboratory, Tampere University, 33014 Tampere, Finland
| | - Mari Lehtimäki
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90014 Oulu, Finland
| | - Arne Raasakka
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway
| | - Venkata P Dandey
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, 4058 Basel, Switzerland
| | - Ilpo Vattulainen
- Computational Physics Laboratory, Tampere University, 33014 Tampere, Finland; Department of Physics, University of Helsinki, 00014 Helsinki, Finland
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, 4058 Basel, Switzerland
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90014 Oulu, Finland; Biocenter Oulu, University of Oulu, 90014 Oulu, Finland; Department of Biomedicine, University of Bergen, 5020 Bergen, Norway.
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9
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Poitelon Y, Kopec AM, Belin S. Myelin Fat Facts: An Overview of Lipids and Fatty Acid Metabolism. Cells 2020; 9:cells9040812. [PMID: 32230947 PMCID: PMC7226731 DOI: 10.3390/cells9040812] [Citation(s) in RCA: 141] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 12/11/2022] Open
Abstract
Myelin is critical for the proper function of the nervous system and one of the most complex cell–cell interactions of the body. Myelination allows for the rapid conduction of action potentials along axonal fibers and provides physical and trophic support to neurons. Myelin contains a high content of lipids, and the formation of the myelin sheath requires high levels of fatty acid and lipid synthesis, together with uptake of extracellular fatty acids. Recent studies have further advanced our understanding of the metabolism and functions of myelin fatty acids and lipids. In this review, we present an overview of the basic biology of myelin lipids and recent insights on the regulation of fatty acid metabolism and functions in myelinating cells. In addition, this review may serve to provide a foundation for future research characterizing the role of fatty acids and lipids in myelin biology and metabolic disorders affecting the central and peripheral nervous system.
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10
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Scapin C, Ferri C, Pettinato E, Zambroni D, Bianchi F, Del Carro U, Belin S, Caruso D, Mitro N, Pellegatta M, Taveggia C, Schwab MH, Nave KA, Feltri ML, Wrabetz L, D'Antonio M. Enhanced axonal neuregulin-1 type-III signaling ameliorates neurophysiology and hypomyelination in a Charcot-Marie-Tooth type 1B mouse model. Hum Mol Genet 2020; 28:992-1006. [PMID: 30481294 DOI: 10.1093/hmg/ddy411] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/30/2018] [Accepted: 11/22/2018] [Indexed: 12/11/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) neuropathies are a group of genetic disorders that affect the peripheral nervous system with heterogeneous pathogenesis and no available treatment. Axonal neuregulin 1 type III (Nrg1TIII) drives peripheral nerve myelination by activating downstream signaling pathways such as PI3K/Akt and MAPK/Erk that converge on master transcriptional regulators of myelin genes, such as Krox20. We reasoned that modulating Nrg1TIII activity may constitute a general therapeutic strategy to treat CMTs that are characterized by reduced levels of myelination. Here we show that genetic overexpression of Nrg1TIII ameliorates neurophysiological and morphological parameters in a mouse model of demyelinating CMT1B, without exacerbating the toxic gain-of-function that underlies the neuropathy. Intriguingly, the mechanism appears not to be related to Krox20 or myelin gene upregulation, but rather to a beneficial rebalancing in the stoichiometry of myelin lipids and proteins. Finally, we provide proof of principle that stimulating Nrg1TIII signaling, by pharmacological suppression of the Nrg1TIII inhibitor tumor necrosis factor-alpha-converting enzyme (TACE/ADAM17), also ameliorates the neuropathy. Thus, modulation of Nrg1TIII by TACE/ADAM17 inhibition may represent a general treatment for hypomyelinating neuropathies.
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Affiliation(s)
| | | | | | | | - Francesca Bianchi
- INSPE, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Ubaldo Del Carro
- INSPE, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | | | - Donatella Caruso
- DiSFeB-Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Nico Mitro
- DiSFeB-Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Marta Pellegatta
- INSPE, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Carla Taveggia
- INSPE, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Markus H Schwab
- Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany.,Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Klaus-Armin Nave
- Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
| | - M Laura Feltri
- DIBIT, Divisions of Genetics and Cell Biology.,Hunter James Kelly Research Institute.,Department of Neurology.,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Lawrence Wrabetz
- DIBIT, Divisions of Genetics and Cell Biology.,Hunter James Kelly Research Institute.,Department of Neurology.,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
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11
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Di Gioacchino M, Bianconi A, Burghammer M, Ciasca G, Bruni F, Campi G. Myelin basic protein dynamics from out-of-equilibrium functional state to degraded state in myelin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183256. [PMID: 32145283 DOI: 10.1016/j.bbamem.2020.183256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 01/15/2023]
Abstract
Living matter is a quasi-stationary out-of-equilibrium system; in this physical condition, structural fluctuations at nano- and meso-scales are needed to understand the physics behind its biological functionality. Myelin has a simple ultrastructure whose fluctuations show correlated disorder in its functional out-of-equilibrium state. However, there is no information on the relationship between this correlated disorder and the dynamics of the intrinsically disordered Myelin Basic Protein (MBP) which is expected to influence the membrane structure and overall functionality. In this work, we have investigated the role of this protein structural dynamics in the myelin ultrastructure fluctuations in various conditions, by using synchrotron Scanning micro X Ray Diffraction and Small Angle X ray Scattering. We have induced the crossover from out-of-equilibrium functional state to in-equilibrium degeneration changing the pH to values far from physiological condition. The observed compression of the cytosolic layer thickness probes that the intrinsic large MBP fluctuations preserve the cytosol structure also in the degraded state. Thus, the transition of myelin ultrastructure from correlated to uncorrelated disordered state, is principally affected by the deformation of the membrane and extracellular domain.
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Affiliation(s)
- Michael Di Gioacchino
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy; Institute of Crystallography, CNR, via Salaria, Km 29.300, 00015 Monterotondo, Roma, Italy; Rome International Center for Materials Science Superstripes (RICMASS), Via dei Sabelli 119A, 00185 Roma, Italy.
| | - Antonio Bianconi
- Institute of Crystallography, CNR, via Salaria, Km 29.300, 00015 Monterotondo, Roma, Italy; Rome International Center for Materials Science Superstripes (RICMASS), Via dei Sabelli 119A, 00185 Roma, Italy; National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow, Russia
| | - Manfred Burghammer
- European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP220, 38043 Grenoble Cedex, France
| | - Gabriele Ciasca
- Physics Institute, Catholic University of Sacred Heart, Largo F. Vito 1, 00168 Rome, Italy
| | - Fabio Bruni
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
| | - Gaetano Campi
- Institute of Crystallography, CNR, via Salaria, Km 29.300, 00015 Monterotondo, Roma, Italy
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12
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Laulumaa S, Koza MM, Seydel T, Kursula P, Natali F. A Quasielastic Neutron Scattering Investigation on the Molecular Self-Dynamics of Human Myelin Protein P2. J Phys Chem B 2019; 123:8178-8185. [PMID: 31483648 DOI: 10.1021/acs.jpcb.9b05320] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human myelin protein P2 is a membrane binding protein believed to maintain correct lipid composition and organization in peripheral nerve myelin. Its function is related to its ability to stack membranes, and this function can be enhanced by the P38G mutation, whereby the overall protein structure does not change but the molecular dynamics increase. Mutations in P2 are linked to human peripheral neuropathy. Here, the dynamics of wild-type P2 and the P38G variant were studied using quasielastic neutron scattering on time scales from 10 ps to 1 ns at 300 K. The results suggest that the mutant protein dynamics are increased on both the fastest and the slowest measured time scales, by increasing the dynamics amplitude and/or the portion of atoms participating in the movement.
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Affiliation(s)
- Saara Laulumaa
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu , University of Oulu , Oulu , Finland.,European Spallation Source , Lund , Sweden
| | | | | | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu , University of Oulu , Oulu , Finland.,Department of Biomedicine , University of Bergen , Bergen , Norway
| | - Francesca Natali
- Institut Laue-Langevin , Grenoble , France.,CNR-IOM, OGG , Grenoble , France
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13
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Laulumaa S, Kursula P. Sub-Atomic Resolution Crystal Structures Reveal Conserved Geometric Outliers at Functional Sites. Molecules 2019; 24:molecules24173044. [PMID: 31443388 PMCID: PMC6749445 DOI: 10.3390/molecules24173044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 01/28/2023] Open
Abstract
Myelin protein 2 (P2) is a peripheral membrane protein of the vertebrate nervous system myelin sheath, having possible roles in both lipid transport and 3D molecular organization of the multilayered myelin membrane. We extended our earlier crystallographic studies on human P2 and refined its crystal structure at an ultrahigh resolution of 0.72 Å in perdeuterated form and 0.86 Å in hydrogenated form. Characteristic differences in C–H…O hydrogen bond patterns were observed between extended β strands, kinked or ending strands, and helices. Often, side-chain C–H groups engage in hydrogen bonding with backbone carbonyl moieties. The data highlight several amino acid residues with unconventional conformations, including both bent aromatic rings and twisted guanidinium groups on arginine side chains, as well as non-planar peptide bonds. In two locations, such non-ideal conformations cluster, providing proof of local functional strain. Other ultrahigh-resolution protein structures similarly contain chemical groups, which break planarity rules. For example, in Src homology 3 (SH3) domains, a conserved bent aromatic residue is observed near the ligand binding site. Fatty acid binding protein (FABP) 3, belonging to the same family as P2, has several side chains and peptide bonds bent exactly as those in P2. We provide a high-resolution snapshot on non-ideal conformations of amino acid residues under local strain, possibly relevant to biological function. Geometric outliers observed in ultrahigh-resolution protein structures are real and likely relevant for ligand binding and conformational changes. Furthermore, the deuteration of protein and/or solvent are promising variables in protein crystal optimization.
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Affiliation(s)
- Saara Laulumaa
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, 90014 Oulu, Finland
- European Spallation Source, 22100 Lund, Sweden
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, 90014 Oulu, Finland.
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway.
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14
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Peripheral myelin protein 2 - a novel cluster of mutations causing Charcot-Marie-Tooth neuropathy. Orphanet J Rare Dis 2019; 14:197. [PMID: 31412900 PMCID: PMC6692960 DOI: 10.1186/s13023-019-1162-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/22/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disorder characterized by wide clinical, genetic and pathomechanistic heterogeneity. Recently, the gene encoding peripheral myelin protein 2 (PMP2) was identified as a novel cause for CMT neuropathy with three mutations that structurally cluster together (p.Ile43Asn, p.Thr51Pro, p.Ile52Thr) reported in five families. RESULTS Using whole exome sequencing and cohort screening we identified two novel missense substitutions in PMP2 in Bulgarian (p.Met114Thr, c.341C > T) and German (p.Val115Ala, c.344 T > C) families. The mutations affect adjacent and highly conserved amino acid residues outside of the known mutation-rich region in the protein. Crystal structure analysis positions the affected residues within a cluster of highly conserved fatty acid coordinating residues implying their functional significance. The clinical, electrophysiological and imaging features in both families were consistent with a childhood onset polyneuropathy with variable patterns of demyelination, slow to very slow progression, and most severe involvement of the peroneal muscles. CONCLUSIONS We expand the genetic and phenotypic spectrum of PMP2-related peripheral neuropathy. Our findings reveal a second mutational cluster in the protein.
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15
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McKillop IH, Girardi CA, Thompson KJ. Role of fatty acid binding proteins (FABPs) in cancer development and progression. Cell Signal 2019; 62:109336. [PMID: 31170472 DOI: 10.1016/j.cellsig.2019.06.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/31/2019] [Accepted: 06/01/2019] [Indexed: 01/06/2023]
Abstract
Fatty acid binding proteins (FABPs) are small, water soluble proteins that bind long chain fatty acids and other biologically active ligands to facilitate intracellular localization. Twelve FABP family members have been identified to date, with 10 isoforms expressed in humans. Functionally, FABPs are important in fatty acid metabolism and transport, with distinct family members having the capacity to influence gene transcription. Expression of FABPs is usually cell/tissue specific to one predominant FABP family member. Dysregulation of FABP expression can occur through genetic mutation and/or environmental-lifestyle influences. In addition to intracellular function, exogenous, circulating FABP expression can occur and is associated with specific disease states such as insulin resistance. A role for FABPs is increasingly being reported in tumor biology with elevated exogenous FABP expression being associated with tumor progression and invasiveness. However, a less clear role has been appreciated for dysregulated FABP expression during cell transformation and early expansion.
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Affiliation(s)
- Iain H McKillop
- Department of Surgery, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Cara A Girardi
- Department of Surgery, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA
| | - Kyle J Thompson
- Department of Surgery, Carolinas Medical Center, Atrium Health, Charlotte, NC 28203, USA.
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16
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Belin S, Ornaghi F, Shackleford G, Wang J, Scapin C, Lopez-Anido C, Silvestri N, Robertson N, Williamson C, Ishii A, Taveggia C, Svaren J, Bansal R, Schwab MH, Nave K, Fratta P, D’Antonio M, Poitelon Y, Feltri ML, Wrabetz L. Neuregulin 1 type III improves peripheral nerve myelination in a mouse model of congenital hypomyelinating neuropathy. Hum Mol Genet 2019; 28:1260-1273. [PMID: 30535360 PMCID: PMC6452193 DOI: 10.1093/hmg/ddy420] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/06/2018] [Accepted: 12/02/2018] [Indexed: 12/13/2022] Open
Abstract
Myelin sheath thickness is precisely regulated and essential for rapid propagation of action potentials along myelinated axons. In the peripheral nervous system, extrinsic signals from the axonal protein neuregulin 1 (NRG1) type III regulate Schwann cell fate and myelination. Here we ask if modulating NRG1 type III levels in neurons would restore myelination in a model of congenital hypomyelinating neuropathy (CHN). Using a mouse model of CHN, we improved the myelination defects by early overexpression of NRG1 type III. Surprisingly, the improvement was independent from the upregulation of Egr2 or essential myelin genes. Rather, we observed the activation of MAPK/ERK and other myelin genes such as peripheral myelin protein 2 and oligodendrocyte myelin glycoprotein. We also confirmed that the permanent activation of MAPK/ERK in Schwann cells has detrimental effects on myelination. Our findings demonstrate that the modulation of axon-to-glial NRG1 type III signaling has beneficial effects and improves myelination defects during development in a model of CHN.
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Affiliation(s)
- Sophie Belin
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Francesca Ornaghi
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
- SR-TIGET, IRCCS, San Raffaele Scientific Institute, Milan, Italy
| | - Ghjuvan’Ghjacumu Shackleford
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jie Wang
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Cristina Scapin
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | | | - Nicholas Silvestri
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Neil Robertson
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Courtney Williamson
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
| | - Akihiro Ishii
- Department of Neuroscience, University of Connecticut Medical School, Farmington, CT, USA
| | - Carla Taveggia
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - John Svaren
- Waisman Center, University of Wisconsin–Madison, Madison, WI, USA
| | - Rashmi Bansal
- Department of Neuroscience, University of Connecticut Medical School, Farmington, CT, USA
| | - Markus H Schwab
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Klaus Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Pietro Fratta
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK
| | - Maurizio D’Antonio
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Yannick Poitelon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - M Laura Feltri
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Lawrence Wrabetz
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
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17
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Neagu AN. Proteome Imaging: From Classic to Modern Mass Spectrometry-Based Molecular Histology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1140:55-98. [PMID: 31347042 DOI: 10.1007/978-3-030-15950-4_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In order to overcome the limitations of classic imaging in Histology during the actually era of multiomics, the multi-color "molecular microscope" by its emerging "molecular pictures" offers quantitative and spatial information about thousands of molecular profiles without labeling of potential targets. Healthy and diseased human tissues, as well as those of diverse invertebrate and vertebrate animal models, including genetically engineered species and cultured cells, can be easily analyzed by histology-directed MALDI imaging mass spectrometry. The aims of this review are to discuss a range of proteomic information emerging from MALDI mass spectrometry imaging comparative to classic histology, histochemistry and immunohistochemistry, with applications in biology and medicine, concerning the detection and distribution of structural proteins and biological active molecules, such as antimicrobial peptides and proteins, allergens, neurotransmitters and hormones, enzymes, growth factors, toxins and others. The molecular imaging is very well suited for discovery and validation of candidate protein biomarkers in neuroproteomics, oncoproteomics, aging and age-related diseases, parasitoproteomics, forensic, and ecotoxicology. Additionally, in situ proteome imaging may help to elucidate the physiological and pathological mechanisms involved in developmental biology, reproductive research, amyloidogenesis, tumorigenesis, wound healing, neural network regeneration, matrix mineralization, apoptosis and oxidative stress, pain tolerance, cell cycle and transformation under oncogenic stress, tumor heterogeneity, behavior and aggressiveness, drugs bioaccumulation and biotransformation, organism's reaction against environmental penetrating xenobiotics, immune signaling, assessment of integrity and functionality of tissue barriers, behavioral biology, and molecular origins of diseases. MALDI MSI is certainly a valuable tool for personalized medicine and "Eco-Evo-Devo" integrative biology in the current context of global environmental challenges.
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Affiliation(s)
- Anca-Narcisa Neagu
- Laboratory of Animal Histology, Faculty of Biology, "Alexandru Ioan Cuza" University of Iasi, Iasi, Romania.
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18
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Graf SA, Heppt MV, Wessely A, Krebs S, Kammerbauer C, Hornig E, Strieder A, Blum H, Bosserhoff AK, Berking C. The myelin protein PMP2 is regulated by SOX10 and drives melanoma cell invasion. Pigment Cell Melanoma Res 2018; 32:424-434. [PMID: 30506895 DOI: 10.1111/pcmr.12760] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 10/05/2018] [Accepted: 11/20/2018] [Indexed: 12/22/2022]
Abstract
The transcription factor sex determining region Y-box 10 (SOX10) plays a key role in the development of melanocytes and glial cells from neural crest precursors. SOX10 is involved in melanoma initiation, proliferation, invasion, and survival. However, specific mediators which impart its oncogenic properties remain widely unknown. To identify target genes of SOX10, we performed RNA sequencing after ectopic expression of SOX10 in human melanoma cells. Among nine differentially regulated genes, peripheral myelin protein 2 (PMP2) was consistently upregulated in several cell lines. Direct regulation of PMP2 by SOX10 was shown by chromatin immunoprecipitation, electrophoretic mobility shift, and luciferase reporter assays. Moreover, a coregulation of PMP2 by SOX10 and early growth response 2 in melanoma cells was found. Phenotypical investigation demonstrated that PMP2 expression can increase melanoma cell invasion. As PMP2 protein was detected only in a subset of melanoma cell lines, it might contribute to melanoma heterogeneity.
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Affiliation(s)
- Saskia Anna Graf
- Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany
| | - Markus Vincent Heppt
- Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany
| | - Anja Wessely
- Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany
| | - Stefan Krebs
- Gene Center, Ludwig-Maximilian University of Munich, Munich, Germany
| | - Claudia Kammerbauer
- Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany
| | - Eva Hornig
- Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany
| | - Annamarie Strieder
- Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany
| | - Helmut Blum
- Gene Center, Ludwig-Maximilian University of Munich, Munich, Germany
| | - Anja-Katrin Bosserhoff
- Department of Biochemistry and Molecular Medicine, Institute of Biochemistry, Emil Fischer Center, University of Erlangen-Nürnberg, Erlangen, Germany.,Comprehensive Cancer Center (CCC) Erlangen-EMN, Erlangen, Germany
| | - Carola Berking
- Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany
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19
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Punetha J, Mackay-Loder L, Harel T, Coban-Akdemir Z, Jhangiani SN, Gibbs RA, Lee I, Terespolsky D, Lupski JR, Posey JE. Identification of a pathogenic PMP2 variant in a multi-generational family with CMT type 1: Clinical gene panels versus genome-wide approaches to molecular diagnosis. Mol Genet Metab 2018; 125:302-304. [PMID: 30249361 PMCID: PMC6326168 DOI: 10.1016/j.ymgme.2018.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 08/15/2018] [Accepted: 08/15/2018] [Indexed: 01/07/2023]
Abstract
Charcot-Marie-Tooth (CMT) disease type 1 is an inherited peripheral neuropathy characterized by demyelination and reduced nerve conduction velocities. We present a multi-generational family with peripheral neuropathy in whom clinical CMT panel testing failed to conclude a molecular diagnosis. We found a PMP2 pathogenic variant c.155T > C, p.(Ile52Thr) that segregates with disease suggesting that PMP2 variants should be considered in patients with neuropathy and that it may be prudent to include in clinical CMT gene panels.
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Affiliation(s)
- Jaya Punetha
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Loren Mackay-Loder
- Department of Laboratory Medicine - Genetics Program, Trillium Health Partners, Mississauga, ON L5M 2N1, Canada
| | - Tamar Harel
- Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem 9112001, Israel
| | - Zeynep Coban-Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ian Lee
- Department of Laboratory Medicine - Genetics Program, Trillium Health Partners, Mississauga, ON L5M 2N1, Canada
| | - Deborah Terespolsky
- Department of Laboratory Medicine - Genetics Program, Trillium Health Partners, Mississauga, ON L5M 2N1, Canada
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
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20
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Amiri M, Yousefnia S, Seyed Forootan F, Peymani M, Ghaedi K, Nasr Esfahani MH. Diverse roles of fatty acid binding proteins (FABPs) in development and pathogenesis of cancers. Gene 2018; 676:171-183. [PMID: 30021130 DOI: 10.1016/j.gene.2018.07.035] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 07/04/2018] [Accepted: 07/12/2018] [Indexed: 12/27/2022]
Abstract
One of the most importantly involved pathways in cancer development is fatty-acid signaling pathway. Synthesized lipids as energetic sources are consumed by cancer cells for proliferation, growth, survival, invasion and angiogenesis. Fatty acids as signaling compounds regulate metabolic and transcriptional networks, survival pathways and inflammatory responses. Aggregation of fatty acids with fatty acid binding proteins (FABPs) facilitates their transportation to different cell organelles. FABPs, a group of lipid binding proteins modulate fatty acid metabolism, cell growth and proliferation and cancer development. They may be used as tumor marker in some cancers. FABPs are expressed in most malignancies such as prostate, breast, liver, bladder and lung cancer which are associated with the incidence, proliferation, metastasis, invasion of tumors. This review introduces several isoforms of FABPs (FABP1-12) and summarizes their function and their possible roles in cancer development through some proposed mechanisms.
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Affiliation(s)
- Mina Amiri
- Department of Modern Biology, ACECR Institute of Higher Education (Isfahan Branch), Isfahan, Iran
| | - Saghar Yousefnia
- Division of Cellular and Molecular Biology, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
| | - Farzad Seyed Forootan
- Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran; Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran.
| | - Maryam Peymani
- Department of Biology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran; Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Kamran Ghaedi
- Division of Cellular and Molecular Biology, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran; Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran.
| | - Mohammad Hossein Nasr Esfahani
- Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
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21
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Jasim SB, Li Z, Guest EE, Hirst JD. DichroCalc: Improvements in Computing Protein Circular Dichroism Spectroscopy in the Near-Ultraviolet. J Mol Biol 2018; 430:2196-2202. [DOI: 10.1016/j.jmb.2017.12.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 11/24/2017] [Accepted: 12/10/2017] [Indexed: 12/13/2022]
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22
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Laulumaa S, Nieminen T, Raasakka A, Krokengen OC, Safaryan A, Hallin EI, Brysbaert G, Lensink MF, Ruskamo S, Vattulainen I, Kursula P. Structure and dynamics of a human myelin protein P2 portal region mutant indicate opening of the β barrel in fatty acid binding proteins. BMC STRUCTURAL BIOLOGY 2018; 18:8. [PMID: 29940944 PMCID: PMC6020228 DOI: 10.1186/s12900-018-0087-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/13/2018] [Indexed: 02/04/2023]
Abstract
Background Myelin is a multilayered proteolipid sheath wrapped around selected axons in the nervous system. Its constituent proteins play major roles in forming of the highly regular membrane structure. P2 is a myelin-specific protein of the fatty acid binding protein (FABP) superfamily, which is able to stack lipid bilayers together, and it is a target for mutations in the human inherited neuropathy Charcot-Marie-Tooth disease. A conserved residue that has been proposed to participate in membrane and fatty acid binding and conformational changes in FABPs is Phe57. This residue is thought to be a gatekeeper for the opening of the portal region upon ligand entry and egress. Results We performed a structural characterization of the F57A mutant of human P2. The mutant protein was crystallized in three crystal forms, all of which showed changes in the portal region and helix α2. In addition, the behaviour of the mutant protein upon lipid bilayer binding suggested more unfolding than previously observed for wild-type P2. On the other hand, membrane binding rendered F57A heat-stable, similarly to wild-type P2. Atomistic molecular dynamics simulations showed opening of the side of the discontinuous β barrel, giving important indications on the mechanism of portal region opening and ligand entry into FABPs. The results suggest a central role for Phe57 in regulating the opening of the portal region in human P2 and other FABPs, and the F57A mutation disturbs dynamic cross-correlation networks in the portal region of P2. Conclusions Overall, the F57A variant presents similar properties to the P2 patient mutations recently linked to Charcot-Marie-Tooth disease. Our results identify Phe57 as a residue regulating conformational changes that may accompany membrane surface binding and ligand exchange in P2 and other FABPs. Electronic supplementary material The online version of this article (10.1186/s12900-018-0087-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Saara Laulumaa
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.,European Spallation Source (ESS), Lund, Sweden
| | - Tuomo Nieminen
- Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Arne Raasakka
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Oda C Krokengen
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Erik I Hallin
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Guillaume Brysbaert
- Unité de Glycobiologie Structurale et Fonctionnelle, University of Lille, CNRS UMR8576 UGSF, F-59000, Lille, France
| | - Marc F Lensink
- Unité de Glycobiologie Structurale et Fonctionnelle, University of Lille, CNRS UMR8576 UGSF, F-59000, Lille, France
| | - Salla Ruskamo
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology, Tampere, Finland.,Department of Physics, University of Helsinki, Helsinki, Finland
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland. .,Department of Biomedicine, University of Bergen, Bergen, Norway.
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23
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Ruskamo S, Nieminen T, Kristiansen CK, Vatne GH, Baumann A, Hallin EI, Raasakka A, Joensuu P, Bergmann U, Vattulainen I, Kursula P. Molecular mechanisms of Charcot-Marie-Tooth neuropathy linked to mutations in human myelin protein P2. Sci Rep 2017; 7:6510. [PMID: 28747762 PMCID: PMC5529448 DOI: 10.1038/s41598-017-06781-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/16/2017] [Indexed: 02/06/2023] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is one of the most common inherited neuropathies. Recently, three CMT1-associated point mutations (I43N, T51P, and I52T) were discovered in the abundant peripheral myelin protein P2. These mutations trigger abnormal myelin structure, leading to reduced nerve conduction velocity, muscle weakness, and distal limb atrophy. P2 is a myelin-specific protein expressed by Schwann cells that binds to fatty acids and membranes, contributing to peripheral myelin lipid homeostasis. We studied the molecular basis of the P2 patient mutations. None of the CMT1-associated mutations alter the overall folding of P2 in the crystal state. P2 disease variants show increased aggregation tendency and remarkably reduced stability, T51P being most severe. In addition, P2 disease mutations affect protein dynamics. Both fatty acid binding by P2 and the kinetics of its membrane interactions are affected by the mutations. Experiments and simulations suggest opening of the β barrel in T51P, possibly representing a general mechanism in fatty acid-binding proteins. Our findings demonstrate that altered biophysical properties and functional dynamics of P2 may cause myelin defects in CMT1 patients. At the molecular level, a few malformed hydrogen bonds lead to structural instability and misregulation of conformational changes related to ligand exchange and membrane binding.
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Affiliation(s)
- Salla Ruskamo
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220, Oulu, Finland
| | - Tuomo Nieminen
- Department of Physics, Tampere University of Technology, 33720, Tampere, Finland
| | | | - Guro H Vatne
- Department of Biomedicine, University of Bergen, 5020, Bergen, Norway
| | - Anne Baumann
- Department of Biomedicine, University of Bergen, 5020, Bergen, Norway
- Division of Psychiatry, Haukeland University Hospital, 5021, Bergen, Norway
| | - Erik I Hallin
- Department of Biomedicine, University of Bergen, 5020, Bergen, Norway
| | - Arne Raasakka
- Department of Biomedicine, University of Bergen, 5020, Bergen, Norway
| | - Päivi Joensuu
- Department of Sustainable Chemistry, Technical Faculty, University of Oulu, 90570, Oulu, Finland
| | - Ulrich Bergmann
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220, Oulu, Finland
- Biocenter Oulu, University of Oulu, 90220, Oulu, Finland
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology, 33720, Tampere, Finland
- Department of Physics, University of Helsinki, 00560, Helsinki, Finland
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220, Oulu, Finland.
- Department of Biomedicine, University of Bergen, 5020, Bergen, Norway.
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The Role of Peripheral Myelin Protein 2 in Remyelination. Cell Mol Neurobiol 2017; 38:487-496. [DOI: 10.1007/s10571-017-0494-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/19/2017] [Indexed: 10/19/2022]
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Tuusa J, Raasakka A, Ruskamo S, Kursula P. Myelin-derived and putative molecular mimic peptides share structural properties in aqueous and membrane-like environments. ACTA ACUST UNITED AC 2017. [DOI: 10.1186/s40893-017-0021-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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26
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Motley WW, Palaima P, Yum SW, Gonzalez MA, Tao F, Wanschitz JV, Strickland AV, Löscher WN, De Vriendt E, Koppi S, Medne L, Janecke AR, Jordanova A, Zuchner S, Scherer SS. De novo PMP2 mutations in families with type 1 Charcot-Marie-Tooth disease. Brain 2016; 139:1649-56. [PMID: 27009151 DOI: 10.1093/brain/aww055] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/25/2016] [Indexed: 11/12/2022] Open
Abstract
We performed whole exome sequencing on a patient with Charcot-Marie-Tooth disease type 1 and identified a de novo mutation in PMP2, the gene that encodes the myelin P2 protein. This mutation (p.Ile52Thr) was passed from the proband to his one affected son, and segregates with clinical and electrophysiological evidence of demyelinating neuropathy. We then screened a cohort of 136 European probands with uncharacterized genetic cause of Charcot-Marie-Tooth disease and identified another family with Charcot-Marie-Tooth disease type 1 that has a mutation affecting an adjacent amino acid (p.Thr51Pro), which segregates with disease. Our genetic and clinical findings in these kindred demonstrate that dominant PMP2 mutations cause Charcot-Marie-Tooth disease type 1.
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Affiliation(s)
- William W Motley
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA Department of Medicine, Pennsylvania Hospital, University of Pennsylvania, Philadelphia, Pennsylvania 19107, USA
| | - Paulius Palaima
- Molecular Neurogenomics Group, VIB Department of Molecular Genetics, University of Antwerp, Universiteitsplein 1, 2650-Antwerpen, Belgium Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Universiteitsplein 1, 2650-Antwerpen, Belgium
| | - Sabrina W Yum
- Department of Pediatrics, Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | - Michael A Gonzalez
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami, Miami, Florida 33136, USA
| | - Feifei Tao
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami, Miami, Florida 33136, USA
| | | | - Alleene V Strickland
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami, Miami, Florida 33136, USA
| | | | - Els De Vriendt
- Molecular Neurogenomics Group, VIB Department of Molecular Genetics, University of Antwerp, Universiteitsplein 1, 2650-Antwerpen, Belgium Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Universiteitsplein 1, 2650-Antwerpen, Belgium
| | - Stefan Koppi
- Department of Neurology, State Hospital of Rankweil, Rankweil, Austria
| | - Livija Medne
- Individualized Medical Genetics Center, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | - Andreas R Janecke
- Division of Human Genetics, Department of Pediatrics, Medical University of Innsbruck, Innsbruck, Austria
| | - Albena Jordanova
- Molecular Neurogenomics Group, VIB Department of Molecular Genetics, University of Antwerp, Universiteitsplein 1, 2650-Antwerpen, Belgium Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Universiteitsplein 1, 2650-Antwerpen, Belgium
| | - Stephan Zuchner
- Department of Human Genetics and Hussman Institute for Human Genomics, University of Miami, Miami, Florida 33136, USA
| | - Steven S Scherer
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Hong YB, Joo J, Hyun YS, Kwak G, Choi YR, Yeo HK, Jwa DH, Kim EJ, Mo WM, Nam SH, Kim SM, Yoo JH, Koo H, Park HT, Chung KW, Choi BO. A Mutation in PMP2 Causes Dominant Demyelinating Charcot-Marie-Tooth Neuropathy. PLoS Genet 2016; 12:e1005829. [PMID: 26828946 PMCID: PMC4735456 DOI: 10.1371/journal.pgen.1005829] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/05/2016] [Indexed: 01/05/2023] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is a heterogeneous group of peripheral neuropathies with diverse genetic causes. In this study, we identified p.I43N mutation in PMP2 from a family exhibiting autosomal dominant demyelinating CMT neuropathy by whole exome sequencing and characterized the clinical features. The age at onset was the first to second decades and muscle atrophy started in the distal portion of the leg. Predominant fatty replacement in the anterior and lateral compartment was similar to that in CMT1A caused by PMP22 duplication. Sural nerve biopsy showed onion bulbs and degenerating fibers with various myelin abnormalities. The relevance of PMP2 mutation as a genetic cause of dominant CMT1 was assessed using transgenic mouse models. Transgenic mice expressing wild type or mutant (p.I43N) PMP2 exhibited abnormal motor function. Electrophysiological data revealed that both mice had reduced motor nerve conduction velocities (MNCV). Electron microscopy revealed that demyelinating fibers and internodal lengths were shortened in both transgenic mice. These data imply that overexpression of wild type as well as mutant PMP2 also causes the CMT1 phenotype, which has been documented in the PMP22. This report might expand the genetic and clinical features of CMT and a further mechanism study will enhance our understanding of PMP2-associated peripheral neuropathy. Isolation of causative mutation is still challenging in genetic diseases with a variety of genetic causes. We discovered a mutation in a novel gene from a family exhibiting a peripheral neuropathy by virtue of next-generation sequencing. Although the family shows characteristic clinical features of hereditary motor and sensory neuropathy, we could not find a mutation from well-known genes. To demonstrate the clinical relevance of the novel gene, we generated transgenic mice, which carry the patients’ mutation within their chromosome. The transgenic mice exhibited the same phenotype as the patients including peripheral neuropathic symptoms and reduced locomotor function. We also observed the affected peripheral nervous system through electron microscopy. It seems that the expression of the mutant protein impairs the myelin of peripheral nervous system. These data might expand the genetic, clinical, and pathophysiological features of the peripheral neuropathy and a further investigation will enhance our understanding of disease in the peripheral nervous system.
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Affiliation(s)
- Young Bin Hong
- Stem Cell and Regenerative Medicine Center, Samsung Medical Center, Seoul, Korea
| | - Jaesoon Joo
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Science and Technology, Sungkyunkwan University, Seoul, Korea
| | - Young Se Hyun
- Department of Biological Science, Kongju National University, Gongju, Korea
| | - Geon Kwak
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Science and Technology, Sungkyunkwan University, Seoul, Korea
| | - Yu-Ri Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Ha Kyung Yeo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Dong Hwan Jwa
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Eun Ja Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
- Neuroscience Center, Samsung Medical Center, Seoul, Korea
| | - Won Min Mo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Soo Hyun Nam
- Department of Biological Science, Kongju National University, Gongju, Korea
| | - Sung Min Kim
- Department of Biological Science, Kongju National University, Gongju, Korea
| | - Jeong Hyun Yoo
- Department of Radiology, Ewha Womans University, School of Medicine, Seoul, Korea
| | - Heasoo Koo
- Department of Pathology, Ewha Womans University, School of Medicine, Seoul, Korea
| | - Hwan Tae Park
- Department of Physiology, College of Medicine, Dong-A University, Busan, Korea
| | - Ki Wha Chung
- Department of Biological Science, Kongju National University, Gongju, Korea
- * E-mail: (KWC); (BOC)
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
- Neuroscience Center, Samsung Medical Center, Seoul, Korea
- * E-mail: (KWC); (BOC)
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28
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Knoll W, Peters J, Kursula P, Gerelli Y, Natali F. Influence of myelin proteins on the structure and dynamics of a model membrane with emphasis on the low temperature regime. J Chem Phys 2015; 141:205101. [PMID: 25429962 DOI: 10.1063/1.4901738] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Myelin is an insulating, multi-lamellar membrane structure wrapped around selected nerve axons. Increasing the speed of nerve impulses, it is crucial for the proper functioning of the vertebrate nervous system. Human neurodegenerative diseases, such as multiple sclerosis, are linked to damage to the myelin sheath through demyelination. Myelin exhibits a well defined subset of myelin-specific proteins, whose influence on membrane dynamics, i.e., myelin flexibility and stability, has not yet been explored in detail. In a first paper [W. Knoll, J. Peters, P. Kursula, Y. Gerelli, J. Ollivier, B. Demé, M. Telling, E. Kemner, and F. Natali, Soft Matter 10, 519 (2014)] we were able to spotlight, through neutron scattering experiments, the role of peripheral nervous system myelin proteins on membrane stability at room temperature. In particular, the myelin basic protein and peripheral myelin protein 2 were found to synergistically influence the membrane structure while keeping almost unchanged the membrane mobility. Further insight is provided by this work, in which we particularly address the investigation of the membrane flexibility in the low temperature regime. We evidence a different behavior suggesting that the proton dynamics is reduced by the addition of the myelin basic protein accompanied by negligible membrane structural changes. Moreover, we address the importance of correct sample preparation and characterization for the success of the experiment and for the reliability of the obtained results.
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Affiliation(s)
- W Knoll
- University Joseph Fourier, UFR PhiTEM, Grenoble, France
| | - J Peters
- University Joseph Fourier, UFR PhiTEM, Grenoble, France
| | | | - Y Gerelli
- Institut Laue-Langevin, Grenoble, France
| | - F Natali
- Institut Laue-Langevin, Grenoble, France
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Laulumaa S, Blakeley MP, Raasakka A, Moulin M, Härtlein M, Kursula P. Production, crystallization and neutron diffraction of fully deuterated human myelin peripheral membrane protein P2. Acta Crystallogr F Struct Biol Commun 2015; 71:1391-5. [PMID: 26527266 PMCID: PMC4631588 DOI: 10.1107/s2053230x15017902] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 09/24/2015] [Indexed: 11/11/2022] Open
Abstract
The molecular details of the formation of the myelin sheath, a multilayered membrane in the nervous system, are to a large extent unknown. P2 is a peripheral membrane protein from peripheral nervous system myelin, which is believed to play a role in this process. X-ray crystallographic studies and complementary experiments have provided information on the structure-function relationships in P2. In this study, a fully deuterated sample of human P2 was produced. Crystals that were large enough for neutron diffraction were grown by a ten-month procedure of feeding, and neutron diffraction data were collected to a resolution of 2.4 Å from a crystal of 0.09 mm(3) in volume. The neutron crystal structure will allow the positions of H atoms in P2 and its fatty-acid ligand to be visualized, as well as shedding light on the fine details of the hydrogen-bonding networks within the P2 ligand-binding cavity.
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Affiliation(s)
- Saara Laulumaa
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 5400, 90014 Oulu, Finland
- European Spallation Source, Lund, Sweden
| | - Matthew P. Blakeley
- Large-Scale Structures Group, Institut Laue–Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Arne Raasakka
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 5400, 90014 Oulu, Finland
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
| | - Martine Moulin
- Life Sciences Group, Institut Laue–Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Michael Härtlein
- Life Sciences Group, Institut Laue–Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, PO Box 5400, 90014 Oulu, Finland
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
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30
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Exome Sequence Analysis Suggests that Genetic Burden Contributes to Phenotypic Variability and Complex Neuropathy. Cell Rep 2015; 12:1169-83. [PMID: 26257172 DOI: 10.1016/j.celrep.2015.07.023] [Citation(s) in RCA: 187] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 05/27/2015] [Accepted: 07/09/2015] [Indexed: 02/08/2023] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is a clinically and genetically heterogeneous distal symmetric polyneuropathy. Whole-exome sequencing (WES) of 40 individuals from 37 unrelated families with CMT-like peripheral neuropathy refractory to molecular diagnosis identified apparent causal mutations in ∼ 45% (17/37) of families. Three candidate disease genes are proposed, supported by a combination of genetic and in vivo studies. Aggregate analysis of mutation data revealed a significantly increased number of rare variants across 58 neuropathy-associated genes in subjects versus controls, confirmed in a second ethnically discrete neuropathy cohort, suggesting that mutation burden potentially contributes to phenotypic variability. Neuropathy genes shown to have highly penetrant Mendelizing variants (HPMVs) and implicated by burden in families were shown to interact genetically in a zebrafish assay exacerbating the phenotype established by the suppression of single genes. Our findings suggest that the combinatorial effect of rare variants contributes to disease burden and variable expressivity.
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31
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Laulumaa S, Nieminen T, Lehtimäki M, Aggarwal S, Simons M, Koza MM, Vattulainen I, Kursula P, Natali F. Dynamics of the Peripheral Membrane Protein P2 from Human Myelin Measured by Neutron Scattering--A Comparison between Wild-Type Protein and a Hinge Mutant. PLoS One 2015; 10:e0128954. [PMID: 26068118 PMCID: PMC4466134 DOI: 10.1371/journal.pone.0128954] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 05/01/2015] [Indexed: 12/01/2022] Open
Abstract
Myelin protein P2 is a fatty acid-binding structural component of the myelin sheath in the peripheral nervous system, and its function is related to its membrane binding capacity. Here, the link between P2 protein dynamics and structure and function was studied using elastic incoherent neutron scattering (EINS). The P38G mutation, at the hinge between the β barrel and the α-helical lid, increased the lipid stacking capacity of human P2 in vitro, and the mutated protein was also functional in cultured cells. The P38G mutation did not change the overall structure of the protein. For a deeper insight into P2 structure-function relationships, information on protein dynamics in the 10 ps to 1 ns time scale was obtained using EINS. Values of mean square displacements mainly from protein H atoms were extracted for wild-type P2 and the P38G mutant and compared. Our results show that at physiological temperatures, the P38G mutant is more dynamic than the wild-type P2 protein, especially on a slow 1-ns time scale. Molecular dynamics simulations confirmed the enhanced dynamics of the mutant variant, especially within the portal region in the presence of bound fatty acid. The increased softness of the hinge mutant of human myelin P2 protein is likely related to an enhanced flexibility of the portal region of this fatty acid-binding protein, as well as to its interactions with the lipid bilayer surface requiring conformational adaptations.
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Affiliation(s)
- Saara Laulumaa
- Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
- German Electron Synchrotron (DESY), Hamburg, Germany
- European Spallation Source (ESS), Lund, Sweden
| | - Tuomo Nieminen
- Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Mari Lehtimäki
- Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Shweta Aggarwal
- Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Mikael Simons
- Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | | | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Petri Kursula
- Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
- German Electron Synchrotron (DESY), Hamburg, Germany
- Department of Biomedicine, University of Bergen, Bergen, Norway
- * E-mail: (PK); (FN)
| | - Francesca Natali
- Institut Laue-Langevin (ILL), Grenoble, France
- CNR-IOM, OGG, Grenoble, France
- * E-mail: (PK); (FN)
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Laulumaa S, Kursula P, Natali F. Neutron scattering studies on protein dynamics using the human myelin peripheral membrane protein P2. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20158302010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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33
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, McGrath JC, Catterall WA, Spedding M, Peters JA, Harmar AJ, Abul-Hasn N, Anderson CM, Anderson CMH, Araiksinen MS, Arita M, Arthofer E, Barker EL, Barratt C, Barnes NM, Bathgate R, Beart PM, Belelli D, Bennett AJ, Birdsall NJM, Boison D, Bonner TI, Brailsford L, Bröer S, Brown P, Calo G, Carter WG, Catterall WA, Chan SLF, Chao MV, Chiang N, Christopoulos A, Chun JJ, Cidlowski J, Clapham DE, Cockcroft S, Connor MA, Cox HM, Cuthbert A, Dautzenberg FM, Davenport AP, Dawson PA, Dent G, Dijksterhuis JP, Dollery CT, Dolphin AC, Donowitz M, Dubocovich ML, Eiden L, Eidne K, Evans BA, Fabbro D, Fahlke C, Farndale R, Fitzgerald GA, Fong TM, Fowler CJ, Fry JR, Funk CD, Futerman AH, Ganapathy V, Gaisnier B, Gershengorn MA, Goldin A, Goldman ID, Gundlach AL, Hagenbuch B, Hales TG, Hammond JR, Hamon M, Hancox JC, Hauger RL, Hay DL, Hobbs AJ, Hollenberg MD, Holliday ND, Hoyer D, Hynes NA, Inui KI, Ishii S, Jacobson KA, Jarvis GE, Jarvis MF, Jensen R, Jones CE, Jones RL, Kaibuchi K, Kanai Y, Kennedy C, Kerr ID, Khan AA, Klienz MJ, Kukkonen JP, Lapoint JY, Leurs R, Lingueglia E, Lippiat J, Lolait SJ, Lummis SCR, Lynch JW, MacEwan D, Maguire JJ, Marshall IL, May JM, McArdle CA, McGrath JC, Michel MC, Millar NS, Miller LJ, Mitolo V, Monk PN, Moore PK, Moorhouse AJ, Mouillac B, Murphy PM, Neubig RR, Neumaier J, Niesler B, Obaidat A, Offermanns S, Ohlstein E, Panaro MA, Parsons S, Pwrtwee RG, Petersen J, Pin JP, Poyner DR, Prigent S, Prossnitz ER, Pyne NJ, Pyne S, Quigley JG, Ramachandran R, Richelson EL, Roberts RE, Roskoski R, Ross RA, Roth M, Rudnick G, Ryan RM, Said SI, Schild L, Sanger GJ, Scholich K, Schousboe A, Schulte G, Schulz S, Serhan CN, Sexton PM, Sibley DR, Siegel JM, Singh G, Sitsapesan R, Smart TG, Smith DM, Soga T, Stahl A, Stewart G, Stoddart LA, Summers RJ, Thorens B, Thwaites DT, Toll L, Traynor JR, Usdin TB, Vandenberg RJ, Villalon C, Vore M, Waldman SA, Ward DT, Willars GB, Wonnacott SJ, Wright E, Ye RD, Yonezawa A, Zimmermann M. The Concise Guide to PHARMACOLOGY 2013/14: overview. Br J Pharmacol 2014; 170:1449-58. [PMID: 24528237 DOI: 10.1111/bph.12444] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties from the IUPHAR database. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. This compilation of the major pharmacological targets is divided into seven areas of focus: G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors & Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and GRAC and provides a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen P H Alexander
- School of Life Sciences, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
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Zenker J, Stettner M, Ruskamo S, Domènech-Estévez E, Baloui H, Médard JJ, Verheijen MHG, Brouwers JF, Kursula P, Kieseier BC, Chrast R. A role of peripheral myelin protein 2 in lipid homeostasis of myelinating Schwann cells. Glia 2014; 62:1502-12. [PMID: 24849898 DOI: 10.1002/glia.22696] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 05/06/2014] [Accepted: 05/07/2014] [Indexed: 01/28/2023]
Abstract
Peripheral myelin protein 2 (Pmp2, P2 or Fabp8), a member of the fatty acid binding protein family, was originally described together with myelin basic protein (Mbp or P1) and myelin protein zero (Mpz or P0) as one of the most abundant myelin proteins in the peripheral nervous system (PNS). Although Pmp2 is predominantly expressed in myelinated Schwann cells, its role in glia is currently unknown. To study its function in PNS biology, we have generated a complete Pmp2 knockout mouse (Pmp2(-/-) ). Comprehensive characterization of Pmp2(-/-) mice revealed a temporary reduction in their motor nerve conduction velocity (MNCV). While this change was not accompanied by any defects in general myelin structure, we detected transitory alterations in the myelin lipid profile of Pmp2(-/-) mice. It was previously proposed that Pmp2 and Mbp have comparable functions in the PNS suggesting that the presence of Mbp can partially mask the Pmp2(-/-) phenotype. Indeed, we found that Mbp lacking Shi(-/-) mice, similar to Pmp2(-/-) animals, have preserved myelin structure and reduced MNCV, but this phenotype was not aggravated in Pmp2(-/-) /Shi(-/-) mutants indicating that Pmp2 and Mbp do not substitute each other's functions in the PNS. These data, together with our observation that Pmp2 binds and transports fatty acids to membranes, uncover a role for Pmp2 in lipid homeostasis of myelinating Schwann cells.
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Affiliation(s)
- Jennifer Zenker
- Department of Medical Genetics, University of Lausanne, Switzerland; Graduate Program in Neurosciences, University of Lausanne, Switzerland
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Knoll W, Peters J, Kursula P, Gerelli Y, Ollivier J, Demé B, Telling M, Kemner E, Natali F. Structural and dynamical properties of reconstituted myelin sheaths in the presence of myelin proteins MBP and P2 studied by neutron scattering. SOFT MATTER 2014; 10:519-529. [PMID: 24651633 DOI: 10.1039/c3sm51393a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The myelin sheath is a tightly packed, multilayered membrane structure wrapped around selected nerve axons in the central and the peripheral nervous system. Because of its electrical insulation of the axons, which allows fast, saltatory nerve impulse conduction, myelin is crucial for the proper functioning of the vertebrate nervous system. A subset of myelin-specific proteins is well-defined, but their influence on membrane dynamics, i.e. myelin stability, has not yet been explored in detail. We investigated the structure and the dynamics of reconstituted myelin membranes on a pico- to nanosecond timescale, influenced by myelin basic protein (MBP) and myelin protein 2 (P2), using neutron diffraction and quasi-elastic neutron scattering. A model for the scattering function describing molecular lipid motions is suggested. Although dynamical properties are not affected significantly by MBP and P2 proteins, they act in a highly synergistic manner influencing the membrane structure.
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Affiliation(s)
- Wiebke Knoll
- University Joseph Fourier UFR PhITEM, Grenoble, France
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36
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Ruskamo S, Yadav RP, Sharma S, Lehtimäki M, Laulumaa S, Aggarwal S, Simons M, Bürck J, Ulrich AS, Juffer AH, Kursula I, Kursula P. Atomic resolution view into the structure-function relationships of the human myelin peripheral membrane protein P2. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:165-76. [PMID: 24419389 PMCID: PMC3919267 DOI: 10.1107/s1399004713027910] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 10/11/2013] [Indexed: 01/03/2023]
Abstract
P2 is a fatty acid-binding protein expressed in vertebrate peripheral nerve myelin, where it may function in bilayer stacking and lipid transport. P2 binds to phospholipid membranes through its positively charged surface and a hydrophobic tip, and accommodates fatty acids inside its barrel structure. The structure of human P2 refined at the ultrahigh resolution of 0.93 Å allows detailed structural analyses, including the full organization of an internal hydrogen-bonding network. The orientation of the bound fatty-acid carboxyl group is linked to the protonation states of two coordinating arginine residues. An anion-binding site in the portal region is suggested to be relevant for membrane interactions and conformational changes. When bound to membrane multilayers, P2 has a preferred orientation and is stabilized, and the repeat distance indicates a single layer of P2 between membranes. Simulations show the formation of a double bilayer in the presence of P2, and in cultured cells wild-type P2 induces membrane-domain formation. Here, the most accurate structural and functional view to date on P2, a major component of peripheral nerve myelin, is presented, showing how it can interact with two membranes simultaneously while going through conformational changes at its portal region enabling ligand transfer.
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Affiliation(s)
- Salla Ruskamo
- Department of Biochemistry, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Ravi P. Yadav
- Molecular Biology Unit, Institute of Medical Sciences (IMS), Banaras Hindu University, Varanasi, India
- Centre for Structural Systems Biology, Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg, Germany
| | - Satyan Sharma
- Department of Biochemistry, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Mari Lehtimäki
- Department of Biochemistry, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Saara Laulumaa
- Department of Biochemistry, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
- Centre for Structural Systems Biology, Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg, Germany
| | - Shweta Aggarwal
- Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Mikael Simons
- Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Jochen Bürck
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute for Technology (KIT), Karlsruhe, Germany
| | - Anne S. Ulrich
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute for Technology (KIT), Karlsruhe, Germany
| | - André H. Juffer
- Department of Biochemistry, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Inari Kursula
- Department of Biochemistry, University of Oulu, Oulu, Finland
- Centre for Structural Systems Biology, Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg, Germany
| | - Petri Kursula
- Department of Biochemistry, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
- Centre for Structural Systems Biology, Helmholtz Centre for Infection Research (CSSB-HZI), German Electron Synchrotron (DESY), Hamburg, Germany
- Department of Chemistry, University of Hamburg, Hamburg, Germany
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Muruganandam G, Bürck J, Ulrich AS, Kursula I, Kursula P. Lipid membrane association of myelin proteins and peptide segments studied by oriented and synchrotron radiation circular dichroism spectroscopy. J Phys Chem B 2013; 117:14983-93. [PMID: 24236572 DOI: 10.1021/jp4098588] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Myelin-specific proteins are either integral or peripheral membrane proteins that, in complex with lipids, constitute a multilayered proteolipid membrane system, the myelin sheath. The myelin sheath surrounds the axons of nerves and enables rapid conduction of axonal impulses. Myelin proteins interact intimately with the lipid bilayer and play crucial roles in the assembly, function, and stability of the myelin sheath. Although myelin proteins have been investigated for decades, their structural properties upon membrane surface binding are still largely unknown. In this study, we have used simplified model systems consisting of synthetic peptides and membrane mimics, such as detergent micelles and/or lipid vesicles, to probe the conformation of peptides using synchrotron radiation circular dichroism spectroscopy (SRCD). Additionally, oriented circular dichroism spectroscopy (OCD) was employed to examine the orientation of myelin peptides in macroscopically aligned lipid bilayers. Various representative peptides from the myelin basic protein (MBP), P0, myelin/oligodencrocyte glycoprotein, and connexin32 (cx32) were studied. A helical peptide from the central immunodominant epitope of MBP showed a highly tilted orientation with respect to the membrane surface, whereas the N-terminal cytoplasmic segment of cx32 folded into a helical structure that was only slightly tilted. The folding of full-length myelin basic protein was, furthermore, studied in a bicelle environment. Our results provide information on the conformation and membrane alignment of important membrane-binding peptides in a membrane-mimicking environment, giving novel insights into the mechanisms of membrane binding and stacking by myelin proteins.
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Affiliation(s)
- Gopinath Muruganandam
- Centre for Structural Systems Biology, Helmholtz Centre for Infection Research (CSSB-HZI) , German Electron Synchrotron (DESY), Hamburg 22607, Germany
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38
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Islamov RR, Lannik NI, Shaimardanova GF, Rezvyakov PN, Tyapkina OV, Rizvanov AA, Chelyshev YA, Kozlovskaya IB, Nikolskii EE. Effect of hindlimb unloading on myelinated fibers in the mouse lumbar spinal cord. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2013; 452:266-8. [PMID: 24150643 DOI: 10.1134/s0012496613050086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Indexed: 11/23/2022]
Affiliation(s)
- R R Islamov
- Kazan State Medical University, ul. Butlerova 49, Kazan, 420012, Tatarstan, Russia
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39
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Elsherbiny ME, Emara M, Godbout R. Interaction of brain fatty acid-binding protein with the polyunsaturated fatty acid environment as a potential determinant of poor prognosis in malignant glioma. Prog Lipid Res 2013; 52:562-70. [PMID: 23981365 DOI: 10.1016/j.plipres.2013.08.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 07/29/2013] [Accepted: 08/13/2013] [Indexed: 11/29/2022]
Abstract
Malignant gliomas are the most common adult brain cancers. In spite of aggressive treatment, recurrence occurs in the great majority of patients and is invariably fatal. Polyunsaturated fatty acids are abundant in brain, particularly ω-6 arachidonic acid (AA) and ω-3 docosahexaenoic acid (DHA). Although the levels of ω-6 and ω-3 polyunsaturated fatty acids are tightly regulated in brain, the ω-6:ω-3 ratio is dramatically increased in malignant glioma, suggesting deregulation of fundamental lipid homeostasis in brain tumor tissue. The migratory properties of malignant glioma cells can be modified by altering the ratio of AA:DHA in growth medium, with increased migration observed in AA-rich medium. This fatty acid-dependent effect on cell migration is dependent on expression of the brain fatty acid binding protein (FABP7) previously shown to bind DHA and AA. Increased levels of enzymes involved in eicosanoid production in FABP7-positive malignant glioma cells suggest that FABP7 is an important modulator of AA metabolism. We provide evidence that increased production of eicosanoids in FABP7-positive malignant glioma growing in an AA-rich environment contributes to tumor infiltration in the brain. We discuss pathways and molecules that may underlie FABP7/AA-mediated promotion of cell migration and FABP7/DHA-mediated inhibition of cell migration in malignant glioma.
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Affiliation(s)
- Marwa E Elsherbiny
- Department of Oncology, University of Alberta, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
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40
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Han H, Myllykoski M, Ruskamo S, Wang C, Kursula P. Myelin-specific proteins: a structurally diverse group of membrane-interacting molecules. Biofactors 2013; 39:233-41. [PMID: 23780694 DOI: 10.1002/biof.1076] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 11/15/2012] [Indexed: 12/15/2022]
Abstract
The myelin sheath is a multilayered membrane in the nervous system, which has unique biochemical properties. Myelin carries a set of specific high-abundance proteins, the structure and function of which are still poorly understood. The proteins of the myelin sheath are involved in a number of neurological diseases, including autoimmune diseases and inherited neuropathies. In this review, we briefly discuss the structural properties and functions of selected myelin-specific proteins (P0, myelin oligodendrocyte glycoprotein, myelin-associated glycoprotein, myelin basic protein, myelin-associated oligodendrocytic basic protein, P2, proteolipid protein, peripheral myelin protein of 22 kDa, 2',3'-cyclic nucleotide 3'-phosphodiesterase, and periaxin); such properties include, for example, interactions with lipid bilayers and the presence of large intrinsically disordered regions in some myelin proteins. A detailed understanding of myelin protein structure and function at the molecular level will be required to fully grasp their physiological roles in the myelin sheath.
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Affiliation(s)
- Huijong Han
- Department of Biochemistry and Biocenter Oulu, University of Oulu, Oulu, Finland
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41
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Abstract
Given the unprecedented tools that are now available for rapidly comparing genomes, the identification and study of genetic and genomic changes that are unique to our species have accelerated, and we are entering a golden age of human evolutionary genomics. Here we provide an overview of these efforts, highlighting important recent discoveries, examples of the different types of human-specific genomic and genetic changes identified, and salient trends, such as the localization of evolutionary adaptive changes to complex loci that are highly enriched for disease associations. Finally, we discuss the remaining challenges, such as the incomplete nature of current genome sequence assemblies and difficulties in linking human-specific genomic changes to human-specific phenotypic traits.
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42
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Lehtimäki M, Laulumaa S, Ruskamo S, Kursula P. Production and crystallization of a panel of structure-based mutants of the human myelin peripheral membrane protein P2. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:1359-62. [PMID: 23143249 PMCID: PMC3515381 DOI: 10.1107/s1744309112039036] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 09/12/2012] [Indexed: 11/10/2022]
Abstract
The myelin sheath is a multilayered membrane that surrounds and insulates axons in the nervous system. One of the proteins specific to the peripheral nerve myelin is P2, a protein that is able to stack lipid bilayers. With the goal of obtaining detailed information on the structure-function relationship of P2, 14 structure-based mutated variants of human P2 were generated and produced. The mutants were designed to potentially affect the binding of lipid bilayers by P2. All mutated variants were also crystallized and preliminary crystallographic data are presented. The structural data from the mutants will be combined with diverse functional assays in order to elucidate the fine details of P2 function at the molecular level.
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Affiliation(s)
- Mari Lehtimäki
- Department of Biochemistry and Biocenter Oulu, Universtity of Oulu, PO Box 3000, 90014 Oulu, Finland
| | - Saara Laulumaa
- Department of Biochemistry and Biocenter Oulu, Universtity of Oulu, PO Box 3000, 90014 Oulu, Finland
- CSSB–HZI, DESY, Notkestrasse 85, 22603 Hamburg, Germany
| | - Salla Ruskamo
- Department of Biochemistry and Biocenter Oulu, Universtity of Oulu, PO Box 3000, 90014 Oulu, Finland
| | - Petri Kursula
- Department of Biochemistry and Biocenter Oulu, Universtity of Oulu, PO Box 3000, 90014 Oulu, Finland
- CSSB–HZI, DESY, Notkestrasse 85, 22603 Hamburg, Germany
- Department of Chemistry, University of Hamburg, Hamburg, Germany
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43
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Smathers RL, Petersen DR. The human fatty acid-binding protein family: evolutionary divergences and functions. Hum Genomics 2011; 5:170-91. [PMID: 21504868 PMCID: PMC3500171 DOI: 10.1186/1479-7364-5-3-170] [Citation(s) in RCA: 310] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Fatty acid-binding proteins (FABPs) are members of the intracellular lipid-binding protein (iLBP) family and are involved in reversibly binding intracellular hydrophobic ligands and trafficking them throughout cellular compartments, including the peroxisomes, mitochondria, endoplasmic reticulum and nucleus. FABPs are small, structurally conserved cytosolic proteins consisting of a water-filled, interior-binding pocket surrounded by ten anti-parallel beta sheets, forming a beta barrel. At the superior surface, two alpha-helices cap the pocket and are thought to regulate binding. FABPs have broad specificity, including the ability to bind long-chain (C16-C20) fatty acids, eicosanoids, bile salts and peroxisome proliferators. FABPs demonstrate strong evolutionary conservation and are present in a spectrum of species including Drosophila melanogaster, Caenorhabditis elegans, mouse and human. The human genome consists of nine putatively functional protein-coding FABP genes. The most recently identified family member, FABP12, has been less studied.
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Affiliation(s)
- Rebecca L Smathers
- Molecular Toxicology and Environmental Health Sciences Program, Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO 80045, USA
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44
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Wang C, Neugebauer U, Bürck J, Myllykoski M, Baumgärtel P, Popp J, Kursula P. Charge isomers of myelin basic protein: structure and interactions with membranes, nucleotide analogues, and calmodulin. PLoS One 2011; 6:e19915. [PMID: 21647440 PMCID: PMC3102069 DOI: 10.1371/journal.pone.0019915] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 04/14/2011] [Indexed: 12/30/2022] Open
Abstract
As an essential structural protein required for tight compaction of the central nervous system myelin sheath, myelin basic protein (MBP) is one of the candidate autoantigens of the human inflammatory demyelinating disease multiple sclerosis, which is characterized by the active degradation of the myelin sheath. In this work, recombinant murine analogues of the natural C1 and C8 charge components (rmC1 and rmC8), two isoforms of the classic 18.5-kDa MBP, were used as model proteins to get insights into the structure and function of the charge isomers. Various biochemical and biophysical methods such as size exclusion chromatography, calorimetry, surface plasmon resonance, small angle X-ray and neutron scattering, Raman and fluorescence spectroscopy, and conventional as well as synchrotron radiation circular dichroism were used to investigate differences between these two isoforms, both from the structural point of view, and regarding interactions with ligands, including calmodulin (CaM), various detergents, nucleotide analogues, and lipids. Overall, our results provide further proof that rmC8 is deficient both in structure and especially in function, when compared to rmC1. While the CaM binding properties of the two forms are very similar, their interactions with membrane mimics are different. CaM can be used to remove MBP from immobilized lipid monolayers made of synthetic lipids--a phenomenon, which may be of relevance for MBP function and its regulation. Furthermore, using fluorescently labelled nucleotides, we observed binding of ATP and GTP, but not AMP, by MBP; the binding of nucleoside triphosphates was inhibited by the presence of CaM. Together, our results provide important further data on the interactions between MBP and its ligands, and on the differences in the structure and function between MBP charge isomers.
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Affiliation(s)
- Chaozhan Wang
- Department of Biochemistry, University of Oulu, Oulu, Finland
| | | | - Jochen Bürck
- Institute for Biological Interfaces 2, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | | | - Peter Baumgärtel
- Berlin Electron Storage Ring Company for Synchrotron Radiation, Helmholtz-Zentrum Berlin, Germany
| | - Jürgen Popp
- Institute of Photonic Technology, Jena, Germany
- Institute for Physical Chemistry, Friedrich-Schiller-University Jena, Jena, Germany
| | - Petri Kursula
- Department of Biochemistry, University of Oulu, Oulu, Finland
- Centre for Structural Systems Biology, German Electron Synchrotron, Hamburg, Germany
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Myllykoski M, Baumgärtel P, Kursula P. Conformations of peptides derived from myelin-specific proteins in membrane-mimetic conditions probed by synchrotron radiation CD spectroscopy. Amino Acids 2011; 42:1467-74. [PMID: 21505824 DOI: 10.1007/s00726-011-0911-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 04/02/2011] [Indexed: 12/22/2022]
Abstract
Myelin is a tightly packed membrane multilayer in the nervous system, which harbours a specific set of quantitatively major proteins. All these proteins interact with the lipid bilayer, being either peripheral or integral membrane proteins. In this study, we examined the conformational properties of peptides from the myelin proteins P0, CNPase, MOBP, P2 and MOG, using trifluoroethanol and micelles of different detergents as membrane-like mimics. The peptides showed significant differences in their folding under the employed conditions, as evidenced by synchrotron radiation circular dichroism spectroscopy. Our experiments provide new structural information on the interactions between myelin proteins and membranes, using a simplified model system of synthetic peptides and micelles.
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Patel AK, Yadav RP, Majava V, Kursula I, Kursula P. Structure of the dimeric autoinhibited conformation of DAPK2, a pro-apoptotic protein kinase. J Mol Biol 2011; 409:369-83. [PMID: 21497605 DOI: 10.1016/j.jmb.2011.03.065] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 03/24/2011] [Accepted: 03/28/2011] [Indexed: 11/27/2022]
Abstract
The death-associated protein kinase (DAPK) family has been characterized as a group of pro-apoptotic serine/threonine kinases that share specific structural features in their catalytic kinase domain. Two of the DAPK family members, DAPK1 and DAPK2, are calmodulin-dependent protein kinases that are regulated by oligomerization, calmodulin binding, and autophosphorylation. In this study, we have determined the crystal and solution structures of murine DAPK2 in the presence of the autoinhibitory domain, with and without bound nucleotides in the active site. The crystal structure shows dimers of DAPK2 in a conformation that is not permissible for protein substrate binding. Two different conformations were seen in the active site upon the introduction of nucleotide ligands. The monomeric and dimeric forms of DAPK2 were further analyzed for solution structure, and the results indicate that the dimers of DAPK2 are indeed formed through the association of two apposed catalytic domains, as seen in the crystal structure. The structures can be further used to build a model for DAPK2 autophosphorylation and to compare with closely related kinases, of which especially DAPK1 is an actively studied drug target. Our structures also provide a model for both homodimerization and heterodimerization of the catalytic domain between members of the DAPK family. The fingerprint of the DAPK family, the basic loop, plays a central role in the dimerization of the kinase domain.
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Affiliation(s)
- Ashok K Patel
- Department of Biochemistry, University of Oulu, Finland
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47
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Sedzik J, Jastrzebski JP. High-resolution structural model of porcine P2 myelin membrane protein with associated fatty acid ligand: fact or artifact? J Neurosci Res 2011; 89:909-20. [PMID: 21425316 DOI: 10.1002/jnr.22612] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 01/06/2011] [Accepted: 01/09/2011] [Indexed: 11/07/2022]
Abstract
Myelin membrane is a biological complex of glial cells origin; it is composed of 25% (w/w) proteins and 75% lipids, and more than 300 proteins are associated with central nervous system myelin (for peripheral nervous system myelin, such data are lacking). Myelin plays an important role in maintaining propagation of nerve signals. To uncover the nature of propagation phenomena, it is essential to study biochemistry of myelin proteins and lipids, myelin composition, and myelin structure. Nearly all myelin proteins are like antigens, causing clinically well-defined devastating diseases; multiple sclerosis and Guillain-Barré syndrome are two of them. In this article, a high-resolution study (1.8 Å) of porcine myelin P2 protein is presented. Myelin was purified from porcine intradural spinal roots, which were stored at -80°C for 10 years before myelin and P2 protein were purified (spinal roots were a gift of Prof. Kunio Kitamura, Saitama Medical School). The three-dimensional structural analysis uncovered embedded 18-carbons-long fatty acid. Some speculative interpretation is presented, to uncover how this ligand of fatty acid may form cholesterol ester and stabilize the myelin structure or form simple raft microdomain. Protein crystallography indicates that the ligand may be 18-carbons-long fatty acid. This is unlike previous work with mass spectrometry, in which three ligands were determined. In other protein crystallography-based studies of P2 (bovine), an oleic fatty acid was suggested, but, for recombinant (human) protein, palmitic acid was found. There is no fatty acid ligand in equine P2 protein.
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Affiliation(s)
- Jan Sedzik
- Department of Chemical Engineering and Technology, Protein Crystallization Facility KTH, Royal Institute of Technology, Stockholm, Sweden.
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