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Luchicchi A, Muñoz‐Gonzalez G, Halperin ST, Strijbis E, van Dijk LHM, Foutiadou C, Uriac F, Bouman PM, Schouten MAN, Plemel J, 't Hart BA, Geurts JJG, Schenk GJ. Micro-diffusely abnormal white matter: An early multiple sclerosis lesion phase with intensified myelin blistering. Ann Clin Transl Neurol 2024; 11:973-988. [PMID: 38425098 PMCID: PMC11021636 DOI: 10.1002/acn3.52015] [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: 11/20/2023] [Revised: 01/03/2024] [Accepted: 01/25/2024] [Indexed: 03/02/2024] Open
Abstract
OBJECTIVE Multiple sclerosis (MS) is a chronic central nervous system disease whose white matter lesion origin remains debated. Recently, we reported subtle changes in the MS normal appearing white matter (NAWM), presenting with an increase in myelin blisters and myelin protein citrullination, which may recapitulate some of the prodromal degenerative processes involved in MS pathogenesis. Here, to clarify the relevance of these changes for subsequent MS myelin degeneration we explored their prevalence in WM regions characterized by subtly reduced myelination (dubbed as micro-diffusely abnormal white matter, mDAWM). METHODS We used an in-depth (immuno)histochemistry approach in 27 MS donors with histological presence of mDAWM and 5 controls. An antibody panel against degenerative markers was combined and the presence of myelin/axonal aberrations was analyzed and compared with the NAWM from the same cases/slices/regions. RESULTS mDAWM-defined areas exhibit ill-defined borders, no signs of Wallerian degeneration, and they associate with visible veins. Remarkably, such areas present with augmented myelin blister frequency, enhanced prevalence of polar myelin phospholipids, citrullination, and degradation of myelin basic protein (MBP) when compared with the NAWM. Furthermore, enhanced reactivity of microglia/macrophages against citrullinated MBP was also observed in this tissue. INTERPRETATION We report a new histologically defined early phase in MS lesion formation, namely mDAWM, which lacks signs of Wallerian pathology. These results support the prelesional nature of the mDAWM. We conceptualize that evolution to pathologically evident lesions comprises the previously documented imbalance of axo-myelinic units (myelin blistering) leading to their degeneration and immune system activation by released myelin components.
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Affiliation(s)
- Antonio Luchicchi
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Gema Muñoz‐Gonzalez
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Saar T. Halperin
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Eva Strijbis
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
- Department of NeurologyAmsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Laura H. M. van Dijk
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
| | - Chrisa Foutiadou
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
| | - Florence Uriac
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
| | - Piet M. Bouman
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Maxime A. N. Schouten
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Jason Plemel
- Department of NeuroscienceUniversity of AlbertaEdmontonAlbertaCanada
| | - Bert A. 't Hart
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Jeroen J. G. Geurts
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
| | - Geert J. Schenk
- Department of Anatomy and NeurosciencesAmsterdam University Medical Centers, location VU Medical Center, Amsterdam NeuroscienceAmsterdamthe Netherlands
- MS Centrum Amsterdam, Amsterdam University Medical Centers, location VU Medical CenterAmsterdamthe Netherlands
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Roy A, Trigun SK. The restoration of hippocampal nerve de-myelination by methylcobalamin relates with the enzymatic regulation of homocysteine level in a rat model of moderate grade hepatic encephalopathy. J Biochem Mol Toxicol 2024; 38:e23695. [PMID: 38511258 DOI: 10.1002/jbt.23695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 02/08/2024] [Accepted: 03/12/2024] [Indexed: 03/22/2024]
Abstract
This article describes how methylcobalamin (MeCbl) restores nerve myelination in a moderate- grade hepatic encephalopathy (MoHE) model of ammonia neurotoxicity. The comparative profiles of myelin basic protein (MBP), homocysteine (Hcy) and methionine synthase (MS: a MeCbl- dependent enzyme) activity versus nerve myelination status were studied in the hippocampus of the control, the MoHE (developed by administering 100 mg/kg bw thioacetamide i.p. for 10 days) and the MoHE rats treated with MeCbl (500 µg/kg BW i.p.) for 7 days. Compared to those of control rats, the hippocampal CA1 and CA3 regions of the MoHE rats showed significantly lower myelinated areas and MBP immunostaining. This coincided with the deranged myelin layering in TEM images, decreased MBP protein and its transcript levels in hippocampus of MoHE rats. However, all these parameters recovered to normal levels after MeCbl treatment. MeCbl is a cofactor of MS that catalyzes the conversion of Hcy to methionine as a feeder step of methylation reactions. We observed significantly increased serum and hippocampal Hcy levels in MoHE rats, however, these levels were restored to control values with a concordant activation of MS due to MeCbl treatment. A significant recovery in neurobehavioral impairments in the MoHE rats due to MeCbl treatment was also observed. These findings suggest that MoHE pathogenesis is associated with deranged nerve myelination in the hippocampus and that MeCbl treatment is able to restore it mainly by activating MS, a MeCbl-dependent Hcy-metabolizing enzyme.
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Affiliation(s)
- Anima Roy
- Biochemistry Section, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Surendra Kumar Trigun
- Biochemistry Section, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India
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Mamulashvili N, Chikviladze M, Shanshiashvili L, Mikeladze D. Myelin basic proteins charge isomers interact differently with the peptidyl arginine deiminase-2. Neuroreport 2024; 35:185-190. [PMID: 38305106 DOI: 10.1097/wnr.0000000000002001] [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: 02/03/2024]
Abstract
The deamination of arginine and its conversion to citrulline is a modification observed in positively charged proteins such as histones or myelin basic protein (MBP). This reaction is catalyzed by peptidyl arginine deiminase (PAD), whose abnormal activation is associated with autoimmune diseases like rheumatoid arthritis and multiple sclerosis. However, the mechanisms that trigger PAD activation and the pathophysiological processes involved in hypercitrullination remain unknown. In this study, we investigated the interaction between PAD and various charged isomers of MBP, each differing in the degree of post-translational modification. Immunoprecipitation experiments were conducted to examine the binding between PAD and the different charge isomers of MBP. Our findings revealed that the phosphorylated forms of MBP (C3 and C4) exhibited a higher affinity for PAD compared to the unmodified (C1) and fully citrullinated forms (C8). Additionally, we observed that only in the presence of the unmodified C1 isomer did PAD undergo autocitrullination, which was inhibited by the endogenous guanidine-containing component, creatine. In the presence of other isomers, PAD did not undergo autocitrullination. Furthermore, we found that the unmodified isomer of MBP-C1 contains methylated arginines, which were not affected by the pre-treatment with PAD. Based on our findings, we propose that the increased phosphorylation of central threonines in the original MBP may trigger PAD activation, leading to increased citrullination of the protein and subsequent disorganization of the myelin sheath. These insights contribute to a better understanding of the underlying mechanisms in autoimmune diseases associated with hypercitrullination, potentially opening new avenues for therapeutic interventions.
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Affiliation(s)
| | | | - Lali Shanshiashvili
- Institute of Chemical Biology, Ilia State University
- Department of Biochemistry, I.Beritashvili Center of Experimental Biomedicine, Tbilisi, Georgia
| | - David Mikeladze
- Institute of Chemical Biology, Ilia State University
- Department of Biochemistry, I.Beritashvili Center of Experimental Biomedicine, Tbilisi, Georgia
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Matsoukas JM, Ligielli I, Chasapis CT, Kelaidonis K, Apostolopoulos V, Mavromoustakos T. Novel Approaches in the Immunotherapy of Multiple Sclerosis: Cyclization of Myelin Epitope Peptides and Conjugation with Mannan. Brain Sci 2021; 11:1583. [PMID: 34942885 PMCID: PMC8699547 DOI: 10.3390/brainsci11121583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 01/07/2023] Open
Abstract
Multiple Sclerosis (MS) is a serious autoimmune disease. The patient in an advanced state of the disease has restrained mobility and remains handicapped. It is therefore understandable that there is a great need for novel drugs and vaccines for the treatment of MS. Herein we summarise two major approaches applied for the treatment of the disease using peptide molecules alone or conjugated with mannan. The first approach focuses on selective myelin epitope peptide or peptide mimetic therapy alone or conjugated with mannan, and the second on immune-therapy by preventing or controlling disease through the release of appropriate cytokines. In both approaches the use of cyclic peptides offers the advantage of increased stability from proteolytic enzymes. In these approaches, the synthesis of myelin epitope peptides conjugated to mannan is of particular interest as this was found to protect mice against experimental autoimmune encephalomyelitis, an animal model of MS, in prophylactic and therapeutic protocols. Protection was peptide-specific and associated with reduced antigen-specific T cell proliferation. The aim of the studies of these peptide epitope analogs is to understand their molecular basis of interactions with human autoimmune T-cell receptor and a MS-associated human leucocyte antigen (HLA)-DR2b. This knowledge will lead the rational design to new beneficial non-peptide mimetic analogs for the treatment of MS. Some issues of the use of nanotechnology will also be addressed as a future trend to tackle the disease. We highlight novel immunomodulation and vaccine-based research against MS based on myelin epitope peptides and strategies developed in our laboratories.
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Affiliation(s)
- John M Matsoukas
- NewDrug PC, Patras Science Park, 265 04 Platani, Greece
- Institute for Health and Sport, Victoria University, Melbourne, VIC 3030, Australia
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Irene Ligielli
- Department of Chemistry, University of Athens, 157 72 Athens, Greece
| | - Christos T Chasapis
- NMR Facility, Instrumental Analysis Laboratory, Institute of Chemical, School of Natural Sciences, University of Patras, 265 04 Patras, Greece
- Engineering Sciences, Foundation for Research and Technology, Hellas (FORTH/ICE-HT), 265 04 Patra, Greece
| | | | - Vasso Apostolopoulos
- Institute for Health and Sport, Victoria University, Melbourne, VIC 3030, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Immunology Program, Melbourne, VIC 3021, Australia
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Celarain N, Tomas-Roig J. Aberrant DNA methylation profile exacerbates inflammation and neurodegeneration in multiple sclerosis patients. J Neuroinflammation 2020; 17:21. [PMID: 31937331 PMCID: PMC6961290 DOI: 10.1186/s12974-019-1667-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 11/27/2019] [Indexed: 12/12/2022] Open
Abstract
Multiple sclerosis (MS) is an autoimmune and demyelinating disease of the central nervous system characterised by incoordination, sensory loss, weakness, changes in bladder capacity and bowel function, fatigue and cognitive impairment, creating a significant socioeconomic burden. The pathogenesis of MS involves both genetic susceptibility and exposure to distinct environmental risk factors. The gene x environment interaction is regulated by epigenetic mechanisms. Epigenetics refers to a complex system that modifies gene expression without altering the DNA sequence. The most studied epigenetic mechanism is DNA methylation. This epigenetic mark participates in distinct MS pathophysiological processes, including blood-brain barrier breakdown, inflammatory response, demyelination, remyelination failure and neurodegeneration. In this study, we also accurately summarised a list of environmental factors involved in the MS pathogenesis and its clinical course. A literature search was conducted using MEDLINE through PubMED and Scopus. In conclusion, an exhaustive study of DNA methylation might contribute towards new pharmacological interventions in MS by use of epigenetic drugs.
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Affiliation(s)
- Naiara Celarain
- Girona Neuroimmunology and Multiple Sclerosis Unit (UNIEM), Dr. Josep Trueta University Hospital and Girona Biomedical Research Institute (IDIBGI), Girona, Spain.
| | - Jordi Tomas-Roig
- Girona Neuroimmunology and Multiple Sclerosis Unit (UNIEM), Dr. Josep Trueta University Hospital and Girona Biomedical Research Institute (IDIBGI), Girona, Spain.
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Bollenbach A, Tsikas D, Lenzen S, Jörns A. Asymmetric dimethylation and citrullination in the LEW.1AR1-iddm rat, an animal model of human type 1 diabetes, and effects of anti-TCR/anti-TNF-α antibody-based therapy. Amino Acids 2019; 52:103-110. [PMID: 31832896 DOI: 10.1007/s00726-019-02811-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 12/03/2019] [Indexed: 12/01/2022]
Abstract
The LEW.1AR1-iddm rat is an animal model of human type 1 diabetes (T1D). We determined by GC-MS the extent of asymmetric dimethylation (prADMA) and citrullination (prCit) of L-arginine residues in organ proteins (pr) of normoglycaemic control (ngCo, n = 6), acutely diabetic (acT1D, n = 6), chronically diabetic (chT1D, n = 4), and cured (cuT1D, n = 4) rats after anti-TCR/anti-TNF-α therapy. Pancreatic prCit and prADMA did not differ between the groups but were correlated (r = 0.728, P = 0.0003, n = 20). acT1D rats had lower prCit levels in spleen and kidney than ngCo rats. cuT1D rats had higher prADMA levels than chT1D rats only in the spleen. Combination therapy re-established normoglycaemia and increased prADMA in the spleen without altering pancreatic prADMA and prCit. Western blotting demonstrated the presence of different prADMA pattern, especially an ≈ 50-kDa prADMA in spleen and pancreas, and an ≈ 25-kDa prADMA in the pancreas only, with the kidney showing only a very faint and small prADMA. Besides the changes in the pancreas during different metabolic states, the spleen may play a stronger role for the recognition of metabolic changes in T1D than thought thus far.
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MESH Headings
- Animals
- Antibodies/immunology
- Antibodies/pharmacology
- Arginine/genetics
- Blood Glucose/genetics
- Citrullination/drug effects
- Citrullination/genetics
- DNA Methylation/genetics
- DNA Methylation/immunology
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Disease Models, Animal
- Humans
- Male
- Pancreas/drug effects
- Pancreas/metabolism
- Rats
- Rats, Inbred Lew
- Receptors, Antigen, T-Cell, alpha-beta/antagonists & inhibitors
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Spleen/drug effects
- Spleen/pathology
- Tumor Necrosis Factor-alpha/antagonists & inhibitors
- Tumor Necrosis Factor-alpha/genetics
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Affiliation(s)
- Alexander Bollenbach
- Institute of Toxicology, Core Unit Proteomics, Hannover Medical School, Carl-Neuberg Str. 1, 30625, Hannover, Germany
| | - Dimitrios Tsikas
- Institute of Toxicology, Core Unit Proteomics, Hannover Medical School, Carl-Neuberg Str. 1, 30625, Hannover, Germany.
| | - Sigurd Lenzen
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
- Institute of Experimental Diabetes Research, Hannover Medical School, Hannover, Germany
| | - Anne Jörns
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
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7
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An Overview of the Intrinsic Role of Citrullination in Autoimmune Disorders. J Immunol Res 2019; 2019:7592851. [PMID: 31886309 PMCID: PMC6899306 DOI: 10.1155/2019/7592851] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 04/03/2019] [Accepted: 09/28/2019] [Indexed: 02/07/2023] Open
Abstract
A protein undergoes many types of posttranslation modification. Citrullination is one of these modifications, where an arginine amino acid is converted to a citrulline amino acid. This process depends on catalytic enzymes such as peptidylarginine deiminase enzymes (PADs). This modification leads to a charge shift, which affects the protein structure, protein-protein interactions, and hydrogen bond formation, and it may cause protein denaturation. The irreversible citrullination reaction is not limited to a specific protein, cell, or tissue. It can target a wide range of proteins in the cell membrane, cytoplasm, nucleus, and mitochondria. Citrullination is a normal reaction during cell death. Apoptosis is normally accompanied with a clearance process via scavenger cells. A defect in the clearance system either in terms of efficiency or capacity may occur due to massive cell death, which may result in the accumulation and leakage of PAD enzymes and the citrullinated peptide from the necrotized cell which could be recognized by the immune system, where the immunological tolerance will be avoided and the autoimmune disorders will be subsequently triggered. The induction of autoimmune responses, autoantibody production, and cytokines involved in the major autoimmune diseases will be discussed.
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Sharma S, Young RJ, Chen J, Chen X, Oh EC, Schiller MR. Minimotifs dysfunction is pervasive in neurodegenerative disorders. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2018; 4:414-432. [PMID: 30225339 PMCID: PMC6139474 DOI: 10.1016/j.trci.2018.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Minimotifs are modular contiguous peptide sequences in proteins that are important for posttranslational modifications, binding to other molecules, and trafficking to specific subcellular compartments. Some molecular functions of proteins in cellular pathways can be predicted from minimotif consensus sequences identified through experimentation. While a role for minimotifs in regulating signal transduction and gene regulation during disease pathogenesis (such as infectious diseases and cancer) is established, the therapeutic use of minimotif mimetic drugs is limited. In this review, we discuss a general theme identifying a pervasive role of minimotifs in the pathomechanism of neurodegenerative diseases. Beyond their longstanding history in the genetics of familial neurodegeneration, minimotifs are also major players in neurotoxic protein aggregation, aberrant protein trafficking, and epigenetic regulation. Generalizing the importance of minimotifs in neurodegenerative diseases offers a new perspective for the future study of neurodegenerative mechanisms and the investigation of new therapeutics.
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Affiliation(s)
- Surbhi Sharma
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- School of Life Sciences, Las Vegas, NV, USA
| | - Richard J. Young
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- School of Life Sciences, Las Vegas, NV, USA
| | - Jingchun Chen
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
| | - Xiangning Chen
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- Department of Psychology, Las Vegas, NV, USA
| | - Edwin C. Oh
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- School of Medicine, Las Vegas, NV, USA
| | - Martin R. Schiller
- Nevada Institute of Personalized Medicine, Las Vegas, NV, USA
- School of Life Sciences, Las Vegas, NV, USA
- School of Medicine, Las Vegas, NV, USA
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Plymire DA, Wing CE, Robinson DE, Patrie SM. Continuous Elution Proteoform Identification of Myelin Basic Protein by Superficially Porous Reversed-Phase Liquid Chromatography and Fourier Transform Mass Spectrometry. Anal Chem 2017; 89:12030-12038. [PMID: 29016107 DOI: 10.1021/acs.analchem.7b02426] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Myelin basic protein (MBP) plays an important structural and functional role in the neuronal myelin sheath. Translated MBP exhibits extreme microheterogeneity with numerous alternative splice variants (ASVs) and post-translational modifications (PTMs) reportedly tied to central nervous system maturation, myelin stability, and the pathobiology of various de- and dys-myelinating disorders. Conventional bioanalytical tools cannot efficiently examine ASV and PTM events simultaneously, which limits understanding of the role of MBP microheterogeneity in human physiology and disease. To address this need, we report on a top-down proteomics pipeline that combines superficially porous reversed-phase liquid chromatography (SPLC), Fourier transform mass spectrometry (FTMS), data-independent acquisition (DIA) with nozzle-skimmer dissociation (NSD), and aligned data processing resources to rapidly characterize abundant MBP proteoforms within murine tissue. The three-tier proteoform identification and characterization workflow resolved four known MBP ASVs and hundreds of differentially modified states from a single 90 min SPLC-FTMS run on ∼0.5 μg of material. This included 323 proteoforms for the 14.1 kDa ASV alone. We also identified two novel ASVs from an alternative transcriptional start site (ATSS) of the MBP gene as well as a never before characterized S-acylation event linking palmitic acid, oleic acid, and stearic acid at C78 of the 17.125 kDa ASV.
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Affiliation(s)
- Daniel A Plymire
- Department of Pathology, UT Southwestern Medical Center , 5323 Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Casey E Wing
- Department of Pathology, UT Southwestern Medical Center , 5323 Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Dana E Robinson
- Department of Pathology, UT Southwestern Medical Center , 5323 Harry Hines Boulevard, Dallas, Texas 75390, United States
| | - Steven M Patrie
- Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Department of Pathology, UT Southwestern Medical Center , 5323 Harry Hines Boulevard, Dallas, Texas 75390, United States
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Sarg B, Faserl K, Lindner HH. Identification of Novel Site-Specific Alterations in the Modification Level of Myelin Basic Protein Isolated from Mouse Brain at Different Ages Using Capillary Electrophoresis-Mass Spectrometry. Proteomics 2017; 17. [DOI: 10.1002/pmic.201700269] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 07/07/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Bettina Sarg
- Division of Clinical Biochemistry, Biocenter; Medical University of Innsbruck; Innsbruck Austria
| | - Klaus Faserl
- Division of Clinical Biochemistry, Biocenter; Medical University of Innsbruck; Innsbruck Austria
| | - Herbert H. Lindner
- Division of Clinical Biochemistry, Biocenter; Medical University of Innsbruck; Innsbruck Austria
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Koushik S, Joshi N, Nagaraju S, Mahmood S, Mudeenahally K, Padmavathy R, Jegatheesan SK, Mullangi R, Rajagopal S. PAD4: pathophysiology, current therapeutics and future perspective in rheumatoid arthritis. Expert Opin Ther Targets 2017; 21:433-447. [PMID: 28281906 DOI: 10.1080/14728222.2017.1294160] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Peptidyl arginine deiminase 4 (PAD4) is an enzyme that plays an important role in gene expression, turning out genetic code into functional products in the body. It is involved in a key post translational modification, which involves the conversion of arginine to citrulline. It regulates various processes such as apoptosis, innate immunity and pluripotency, while its dysregulation has a great impact on the genesis of various diseases. Over the last few years PAD4 has emerged as a potential therapeutic target for the treatment of rheumatoid arthritis (RA). Areas covered: In this review, we discuss the basic structure and function of PAD4, along with the role of altered PAD4 activity in the onset of RA and other maladies. We also elucidate the role of PAD4 variants in etiology of RA among several ethnic groups and the current pre-clinical inhibitors to regulate PAD4. Expert opinion: Citrullination has a crucial role in RA and several other disorders. Since PAD4 is an initiator of the citrullination, it is an important therapeutic target for inflammatory diseases. Therefore, an in depth knowledge of the roles and activity of PAD4 is required to explore more effective ways to conquer PAD4 related ailments, especially RA.
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Affiliation(s)
- Sindhu Koushik
- a Bioinformatics , Jubilant Biosys Ltd ., Bangalore , India
| | - Nivedita Joshi
- a Bioinformatics , Jubilant Biosys Ltd ., Bangalore , India
| | | | - Sameer Mahmood
- a Bioinformatics , Jubilant Biosys Ltd ., Bangalore , India
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12
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Cyclic citrullinated MBP 87-99 peptide stimulates T cell responses: Implications in triggering disease. Bioorg Med Chem 2016; 25:528-538. [PMID: 27908754 DOI: 10.1016/j.bmc.2016.11.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 11/11/2016] [Indexed: 11/20/2022]
Abstract
Amino acid mutations to agonist peptide epitopes of myelin proteins have been used to modulate immune responses and experimental autoimmune encephalomyelitis (EAE, animal model of multiple sclerosis). Such amino acid alteration are termed, altered peptide ligands (APL). We have shown that the agonist myelin basic protein (MBP) 87-99 epitope (MBP87-99) with crucial T cell receptor (TCR) substitutions at positions 91 and 96 (K91,P96 (TCR contact residues) to R91,A96; [R91,A96]MBP87-99) results in altered T cell responses and inhibits EAE symptoms. In this study, the role of citrullination of arginines in [R91,A96]MBP87-99 peptide analog was determined using in vivo experiments in combination with computational studies. The immunogenicity of linear [Cit91,A96,Cit97]MBP87-99 and its cyclic analog - cyclo(87-99)[Cit91,A96,Cit97]MBP87-99 when conjugated to the carrier mannan (polysaccharide) were studied in SJL/J mice. It was found that mannosylated cyclo(87-99)[Cit91,A96,Cit97]MBP87-99 peptide induced strong T cell proliferative responses and IFN-gamma cytokine secretion compared with the linear one. Moreover, the interaction of linear and cyclic peptide analogs with the major histocompatibility complex (MHC II, H2-IAs) and TCR was analyzed using molecular dynamics simulations at the receptor level, in order to gain a better understanding of the molecular recognition mechanisms that underly the different immunological profiles of citrullinated peptides compared to its agonist native counterpart MBP87-99 epitope. The results demonstrate that the citrullination of arginine in combination with the backbone conformation of mutated linear and cyclic analogs are significant elements for the immune response triggering the induction of pro-inflammatory cytokines.
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Metzemaekers M, Van Damme J, Mortier A, Proost P. Regulation of Chemokine Activity - A Focus on the Role of Dipeptidyl Peptidase IV/CD26. Front Immunol 2016; 7:483. [PMID: 27891127 PMCID: PMC5104965 DOI: 10.3389/fimmu.2016.00483] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 10/21/2016] [Indexed: 12/15/2022] Open
Abstract
Chemokines are small, chemotactic proteins that play a crucial role in leukocyte migration and are, therefore, essential for proper functioning of the immune system. Chemokines exert their chemotactic effect by activation of chemokine receptors, which are G protein-coupled receptors (GPCRs), and interaction with glycosaminoglycans (GAGs). Furthermore, the exact chemokine function is modulated at the level of posttranslational modifications. Among the different types of posttranslational modifications that were found to occur in vitro and in vivo, i.e., proteolysis, citrullination, glycosylation, and nitration, NH2-terminal proteolysis of chemokines has been described most intensively. Since the NH2-terminal chemokine domain mediates receptor interaction, NH2-terminal modification by limited proteolysis or amino acid side chain modification can drastically affect their biological activity. An enzyme that has been shown to provoke NH2-terminal proteolysis of various chemokines is dipeptidyl peptidase IV or CD26. This multifunctional protein is a serine protease that preferably cleaves dipeptides from the NH2-terminal region of peptides and proteins with a proline or alanine residue in the penultimate position. Various chemokines possess such a proline or alanine residue, and CD26-truncated forms of these chemokines have been identified in cell culture supernatant as well as in body fluids. The effects of CD26-mediated proteolysis in the context of chemokines turned out to be highly complex. Depending on the chemokine ligand, loss of these two NH2-terminal amino acids can result in either an increased or a decreased biological activity, enhanced receptor specificity, inactivation of the chemokine ligand, or generation of receptor antagonists. Since chemokines direct leukocyte migration in homeostatic as well as pathophysiologic conditions, CD26-mediated proteolytic processing of these chemotactic proteins may have significant consequences for appropriate functioning of the immune system. After introducing the chemokine family together with the GPCRs and GAGs, as main interaction partners of chemokines, and discussing the different forms of posttranslational modifications, this review will focus on the intriguing relationship of chemokines with the serine protease CD26.
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Affiliation(s)
- Mieke Metzemaekers
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven , Leuven , Belgium
| | - Jo Van Damme
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven , Leuven , Belgium
| | - Anneleen Mortier
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven , Leuven , Belgium
| | - Paul Proost
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven , Leuven , Belgium
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DNA Methylation: a New Player in Multiple Sclerosis. Mol Neurobiol 2016; 54:4049-4059. [PMID: 27314687 DOI: 10.1007/s12035-016-9966-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 06/08/2016] [Indexed: 12/11/2022]
Abstract
Multiple sclerosis (MS) is a neurological and chronic inflammatory disease that is mediated by demyelination and axonal degeneration in the central nervous system (CNS). Studies have shown that immune system components such as CD4+, CD8+, CD44+ T cells, B lymphatic cells, and inflammatory cytokines play a critical role in inflammatory processes and myelin damage associated with MS. Nevertheless, the pathogenesis of MS remains poorly defined. DNA methylation, a significant epigenetic modification, is reported to be extensively involved in MS pathogenesis through the regulation of gene expression. This review focuses on DNA methylation involved in MS pathogenesis. Evidence showed the hypermethylation of human leukocyte antigen-DRB1 (HLA-DRB1) in CD4+ T cells, the genome-wide DNA methylation in CD8+ T cells, the hypermethylation of interleukin-4 (IL-4)/forkhead winged helix transcription factor 3 (Foxp3), and the demethylation of interferon-γ (IFN-γ)/IL-17a in CD44+ encephalitogenic T cells. Studies also showed the hypermethylation of SH2-containing protein tyrosine phosphatase-1 (SHP-1) in peripheral blood mononuclear cells (PBMCs) and methylated changes of genes regulating oligodendrocyte and neuronal function in normal-appearing white matter. Clarifying the mechanism of aberrant methylation on MS may explain part of the pathology and will lead to the development of a new therapeutic target for the treatment of MS in the future.
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Substitutions mimicking deimination and phosphorylation of 18.5-kDa myelin basic protein exert local structural effects that subtly influence its global folding. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1262-77. [DOI: 10.1016/j.bbamem.2016.02.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/30/2016] [Accepted: 02/17/2016] [Indexed: 11/20/2022]
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Myelin Basic Protein Citrullination in Multiple Sclerosis: A Potential Therapeutic Target for the Pathology. Neurochem Res 2016; 41:1845-56. [PMID: 27097548 DOI: 10.1007/s11064-016-1920-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/02/2016] [Accepted: 04/13/2016] [Indexed: 10/21/2022]
Abstract
Multiple sclerosis (MS) is a multifactorial demyelinating disease characterized by neurodegenerative events and autoimmune response against myelin component. Citrullination or deimination, a post-translational modification of protein-bound arginine into citrulline, catalyzed by Ca(2+) dependent peptidylarginine deiminase enzyme (PAD), plays an essential role in physiological processes include gene expression regulation, apoptosis and the plasticity of the central nervous system, while aberrant citrullination can generate new epitopes, thus involving in the initiation and/or progression of autoimmune disorder like MS. Myelin basic protein (MBP) is the major myelin protein and is generally considered to maintain the stability of the myelin sheath. This review describes the MBP citrullination and its consequence, as well as offering further support for the "inside-out" hypothesis that MS is primarily a neurodegenerative disease with secondary inflammatory demyelination. In addition, it discusses the role of MBP citrullination in the immune inflammation and explores the potential of inhibition of PAD enzymes as a therapeutic strategy for the disease.
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Chicooree N, Unwin RD, Griffiths JR. The application of targeted mass spectrometry-based strategies to the detection and localization of post-translational modifications. MASS SPECTROMETRY REVIEWS 2015; 34:595-626. [PMID: 24737647 DOI: 10.1002/mas.21421] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 12/10/2013] [Indexed: 06/03/2023]
Abstract
This review describes some of the more interesting and imaginative ways in which mass spectrometry has been utilized to study a number of important post-translational modifications over the past two decades; from circa 1990 to 2013. A diverse range of modifications is covered, including citrullination, sulfation, hydroxylation and sumoylation. A summary of the biological role of each modification described, along with some brief mechanistic detail, is also included. Emphasis has been placed on strategies specifically aimed at detecting target modifications, as opposed to more serendipitous modification discovery approaches, which rely upon straightforward product ion scanning methods. The authors have intentionally excluded from this review both phosphorylation and glycosylation since these major modifications have been extensively reviewed elsewhere.
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Affiliation(s)
- Navin Chicooree
- CRUK Manchester Institute, University of Manchester, Wilmslow Road, Manchester, M20 4BX, UK
- School of Chemistry, University of Manchester, Brunswick Street, Manchester, M13 9SU, UK
| | - Richard D Unwin
- Centre for Advanced Discovery and Experimental Therapeutics (CADET), Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, M13 9WL, UK
- Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
| | - John R Griffiths
- CRUK Manchester Institute, University of Manchester, Wilmslow Road, Manchester, M20 4BX, UK
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MyelStones: the executive roles of myelin basic protein in myelin assembly and destabilization in multiple sclerosis. Biochem J 2015; 472:17-32. [DOI: 10.1042/bj20150710] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The classic isoforms of myelin basic protein (MBP, 14–21.5 kDa) are essential to formation of the multilamellar myelin sheath of the mammalian central nervous system (CNS). The predominant 18.5-kDa isoform links together the cytosolic surfaces of oligodendrocytes, but additionally participates in cytoskeletal turnover and membrane extension, Fyn-mediated signalling pathways, sequestration of phosphoinositides and maintenance of calcium homoeostasis. All MBP isoforms are intrinsically disordered proteins (IDPs) that interact via molecular recognition fragments (MoRFs), which thereby undergo local disorder-to-order transitions. Their conformations and associations are modulated by environment and by a dynamic barcode of post-translational modifications, particularly phosphorylation by mitogen-activated and other protein kinases and deimination [a hallmark of demyelination in multiple sclerosis (MS)]. The MBPs are thus to myelin what basic histones are to chromatin. Originally thought to be merely structural proteins forming an inert spool, histones are now known to be dynamic entities involved in epigenetic regulation and diseases such as cancer. Analogously, the MBPs are not mere adhesives of compact myelin, but active participants in oligodendrocyte proliferation and in membrane process extension and stabilization during myelinogenesis. A central segment of these proteins is pivotal in membrane-anchoring and SH3 domain (Src homology 3) interaction. We discuss in the present review advances in our understanding of conformational conversions of this classic basic protein upon membrane association, including new thermodynamic analyses of transitions into different structural ensembles and how a shift in the pattern of its post-translational modifications is associated with the pathogenesis and potentially onset of demyelination in MS.
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Kholia S, Jorfi S, Thompson PR, Causey CP, Nicholas AP, Inal JM, Lange S. A novel role for peptidylarginine deiminases in microvesicle release reveals therapeutic potential of PAD inhibition in sensitizing prostate cancer cells to chemotherapy. J Extracell Vesicles 2015; 4:26192. [PMID: 26095379 PMCID: PMC4475687 DOI: 10.3402/jev.v4.26192] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 04/30/2015] [Accepted: 05/06/2015] [Indexed: 12/18/2022] Open
Abstract
INTRODUCTION Protein deimination, defined as the post-translational conversion of protein-bound arginine to citrulline, is carried out by a family of 5 calcium-dependent enzymes, the peptidylarginine deiminases (PADs) and has been linked to various cancers. Cellular microvesicle (MV) release, which is involved in cancer progression, and deimination have not been associated before. We hypothesize that elevated PAD expression, observed in cancers, causes increased MV release in cancer cells and contributes to cancer progression. BACKGROUND We have previously reported that inhibition of MV release sensitizes cancer cells to chemotherapeutic drugs. PAD2 and PAD4, the isozymes expressed in patients with malignant tumours, can be inhibited with the pan-PAD-inhibitor chloramidine (Cl-am). We sought to investigate whether Cl-am can inhibit MV release and whether this pathway could be utilized to further increase the sensitivity of cancer cells to drug-directed treatment. METHODS Prostate cancer cells (PC3) were induced to release high levels of MVs upon BzATP stimulation of P2X7 receptors. Western blotting with the pan-protein deimination antibody F95 was used to detect a range of deiminated proteins in cells stimulated to microvesiculate. Changes in deiminated proteins during microvesiculation were revealed by immunoprecipitation and immunoblotting, and mass spectrometry identified deiminated target proteins with putative roles in microvesiculation. CONCLUSION We report for the first time a novel function of PADs in the biogenesis of MVs in cancer cells. Our results reveal that during the stimulation of prostate cancer cells (PC3) to microvesiculate, PAD2 and PAD4 expression levels and the deimination of cytoskeletal actin are increased. Pharmacological inhibition of PAD enzyme activity using Cl-am significantly reduced MV release and abrogated the deimination of cytoskeletal actin. We demonstrated that combined Cl-am and methotrexate (MTX) treatment of prostate cancer cells increased the cytotoxic effect of MTX synergistically. Refined PAD inhibitors may form part of a novel combination therapy in cancer treatment.
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Affiliation(s)
- Sharad Kholia
- Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK
| | - Samireh Jorfi
- Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK
| | - Paul R Thompson
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, USA
| | - Corey P Causey
- Department of Chemistry, University of North Florida, Jacksonville, FL, USA
| | - Anthony P Nicholas
- Department of Neurology, University of Alabama at Birmingham, Birmingham, VA, USA
- Birmingham VA Medical Center, Birmingham, AL, USA
| | - Jameel M Inal
- Cellular and Molecular Immunology Research Centre, School of Human Sciences, London Metropolitan University, London, UK;
| | - Sigrun Lange
- School of Pharmacy, University College London, London, UK;
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Dror Y, Hopp M. Hair for brain trade-off, a metabolic bypass for encephalization. SPRINGERPLUS 2014; 3:562. [PMID: 25332862 PMCID: PMC4190188 DOI: 10.1186/2193-1801-3-562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 09/15/2014] [Indexed: 02/03/2023]
Abstract
Hair loss in humans is perplexing and raises many hypothetical explanations. This paper suggests that hair loss in humans is metabolically related to encephalization; and that hair covered hominids would have been unable to evolve large brains because of a dietary restriction of several amino acids which are essential for hair and brain development. We use simulations to imply that hair loss must have preceded increase in brain size & volume. In this respect we see hair loss as a major force in human evolution. We assume that hair reduction required favorable climatic conditions and must have been quick. Using evolutionary and ecological time scales, we pinpoint hair loss to a period around 2.2-2.4 million years ago. The dating is further supported by a rapid selection at that time of the sialic acid deletion mutation which may have protected growing human brains against calcium ion flux. In summary we view encephalization, in part, as a metabolic trade-off between hair and brain. Other biochemical changes may have intervened in the process too; and the deletion mutation of sialic acid hydroxylation may have been involved as well.
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Affiliation(s)
- Yosef Dror
- Biochemistry and Human Nutrition, Faculty of Agriculture, The Hebrew University, 76100 Rehovot, Israel
| | - Michael Hopp
- Department of Geography, Tel Aviv University, Tel Aviv, Israel
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Whiteley CG. Arginine metabolising enzymes as targets against Alzheimers’ disease. Neurochem Int 2014; 67:23-31. [DOI: 10.1016/j.neuint.2014.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 01/26/2014] [Accepted: 01/28/2014] [Indexed: 01/26/2023]
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Collado JA, Guitart C, Ciudad MT, Alvarez I, Jaraquemada D. The Repertoires of Peptides Presented by MHC-II in the Thymus and in Peripheral Tissue: A Clue for Autoimmunity? Front Immunol 2013; 4:442. [PMID: 24381570 PMCID: PMC3865459 DOI: 10.3389/fimmu.2013.00442] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 11/26/2013] [Indexed: 11/13/2022] Open
Abstract
T-cell tolerance to self-antigens is established in the thymus through the recognition by developing thymocytes of self-peptide-MHC complexes and induced and maintained in the periphery. Efficient negative selection of auto-reactive T cells in the thymus is dependent on the in situ expression of both ubiquitous and tissue-restricted self-antigens and on the presentation of derived peptides. Weak or inadequate intrathymic expression of self-antigens increases the risk to generate an autoimmune-prone T-cell repertoire. Indeed, even small changes of self-antigen expression in the thymus affect negative selection and increase the predisposition to autoimmunity. Together with other mechanisms, tolerance is maintained in the peripheral lymphoid organs via the recognition by mature T cells of a similar set of self-peptides in homeostatic conditions. However, non-lymphoid peripheral tissue, where organ-specific autoimmunity takes place, often have differential functional processes that may lead to the generation of epitopes that are absent or non-presented in the thymus. These putative differences between peptides presented by MHC molecules in the thymus and in peripheral tissues might be a major key to the initiation and maintenance of autoimmune conditions.
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Affiliation(s)
- Javier A Collado
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Carolina Guitart
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - M Teresa Ciudad
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Iñaki Alvarez
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
| | - Dolores Jaraquemada
- Department of Cell Biology, Physiology and Immunology, Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , Barcelona , Spain
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Moelants EA, Mortier A, Van Damme J, Proost P, Loos T. Peptidylarginine deiminases: physiological function, interaction with chemokines and role in pathology. DRUG DISCOVERY TODAY. TECHNOLOGIES 2013; 9:e227-314. [PMID: 24063741 DOI: 10.1016/j.ddtec.2012.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Jin Z, Fu Z, Yang J, Troncosco J, Everett AD, Van Eyk JE. Identification and characterization of citrulline-modified brain proteins by combining HCD and CID fragmentation. Proteomics 2013; 13:2682-91. [PMID: 23828821 PMCID: PMC4864592 DOI: 10.1002/pmic.201300064] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 05/01/2013] [Accepted: 06/26/2013] [Indexed: 11/09/2022]
Abstract
Citrullination is a protein PTM of arginine residues catalyzed by peptidylarginine deiminase. Protein citrullination has been detected in the CNS and associated with a number of neurological diseases. However, identifying citrullinated proteins from complex mixtures and pinpointing citrullinated residues have been limited. Using RP LC and high-resolution MS, this study determined in vitro citrullination sites of glial fibrillary acid protein (GFAP), neurogranin (NRGN/RC3), and myelin basic protein (MBP) and in vivo sites in brain protein extract. Human GFAP has five endogenous citrullination sites, R30, R36, R270, R406, and R416, and MBP has 14 in vivo citrullination sites. Human NRGN/RC3 was found citrullinated at residue R68. The sequence of citrullinated peptides and citrullination sites were confirmed from peptides identified in trypsin, Lys-C, and Glu-C digests. The relative ratio of citrullination was estimated by simultaneous identification of citrullinated and unmodified peptides from Alzheimer's and control brain samples. The site occupancy of citrullination at the residue R68 of NRGN ranged from 1.6 to 9.5%. Compared to CID, higher-energy collisional dissociation (HCD) mainly produced protein backbone fragmentation for citrullinated peptides. CID-triggered HCD fragmentation is an optimal approach for the identification of citrullinated peptides in complex protein digests.
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Affiliation(s)
- Zhicheng Jin
- Department of Medicine, Cardiology, Johns Hopkins University, Baltimore, MD
| | - Zongming Fu
- Department of Pediatrics, Hematology, Johns Hopkins University, Baltimore, MD
| | - Jun Yang
- Department of Pediatrics, Cardiology, Johns Hopkins University, Baltimore, MD
| | - Juan Troncosco
- Department of Pathology, Neuropathology, Johns Hopkins University, Baltimore, MD
| | - Allen D. Everett
- Department of Pediatrics, Cardiology, Johns Hopkins University, Baltimore, MD
| | - Jennifer E. Van Eyk
- Department of Medicine, Cardiology, Johns Hopkins University, Baltimore, MD
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, MD
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Verhey LH, Sled JG. Advanced magnetic resonance imaging in pediatric multiple sclerosis. Neuroimaging Clin N Am 2013; 23:337-54. [PMID: 23608694 DOI: 10.1016/j.nic.2012.12.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This review summarizes results from studies that have applied advanced magnetic resonance (MR) imaging techniques to patients with pediatric-onset multiple sclerosis (MS), and includes a discussion of cortical imaging techniques, volumetry, magnetization transfer and diffusion tensor imaging, proton magnetic resonance spectroscopy, and functional MR imaging. Multicenter studies on the sensitivity of these techniques to natural history of disease and treatment response are required before their implementation into clinical practice.
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Karsdal MA, Nielsen MJ, Sand JM, Henriksen K, Genovese F, Bay-Jensen AC, Smith V, Adamkewicz JI, Christiansen C, Leeming DJ. Extracellular matrix remodeling: the common denominator in connective tissue diseases. Possibilities for evaluation and current understanding of the matrix as more than a passive architecture, but a key player in tissue failure. Assay Drug Dev Technol 2012; 11:70-92. [PMID: 23046407 DOI: 10.1089/adt.2012.474] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Increased attention is paid to the structural components of tissues. These components are mostly collagens and various proteoglycans. Emerging evidence suggests that altered components and noncoded modifications of the matrix may be both initiators and drivers of disease, exemplified by excessive tissue remodeling leading to tissue stiffness, as well as by changes in the signaling potential of both intact matrix and fragments thereof. Although tissue structure until recently was viewed as a simple architecture anchoring cells and proteins, this complex grid may contain essential information enabling the maintenance of the structure and normal functioning of tissue. The aims of this review are to (1) discuss the structural components of the matrix and the relevance of their mutations to the pathology of diseases such as fibrosis and cancer, (2) introduce the possibility that post-translational modifications (PTMs), such as protease cleavage, citrullination, cross-linking, nitrosylation, glycosylation, and isomerization, generated during pathology, may be unique, disease-specific biochemical markers, (3) list and review the range of simple enzyme-linked immunosorbent assays (ELISAs) that have been developed for assessing the extracellular matrix (ECM) and detecting abnormal ECM remodeling, and (4) discuss whether some PTMs are the cause or consequence of disease. New evidence clearly suggests that the ECM at some point in the pathogenesis becomes a driver of disease. These pathological modified ECM proteins may allow insights into complicated pathologies in which the end stage is excessive tissue remodeling, and provide unique and more pathology-specific biochemical markers.
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Zhang C, Walker AK, Zand R, Moscarello MA, Yan JM, Andrews PC. Myelin basic protein undergoes a broader range of modifications in mammals than in lower vertebrates. J Proteome Res 2012; 11:4791-802. [PMID: 22420465 PMCID: PMC3612544 DOI: 10.1021/pr201196e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Myelin basic protein (MBP) is an important component of the myelin sheath surrounding neurons, and it is directly affected in demyelinating diseases. MBP contains a relatively large number of post-translational modifications (PTMs), which have been reported to play a role in multiple sclerosis, while MBPs from lower vertebrates have been reported to be incapable of inducing multiple sclerosis or allergic encephalitis. This study reveals the extent of differences in PTM patterns for mammalian and nonmammalian MBPs. This included intact mass and de novo sequence analysis of approximately 85% of rattlesnake MBP, the first reptile MBP to be characterized, and of bovine MBP. We identified 12 PTMs at 11 sites in the five bovine MBP charge components, which include both previously reported and novel modifications. The most notable modification is an acetylation of lysine 121. Other modifications found in bovine MBP include N-terminal acetylation in components C1, C2, and C3; oxidation of methionine 19 in all five components; all charge isomers having both a mono- and dimethylated (symmetric) arginine at position 106; deimination in arginines 23 and 47 found only in component C8b; deimination of arginine 96 and deamidation in glutamine 102 found in components C2, C3, C8a, and C8b; phosphorylation in threonine 97 restricted to charge components C2 and C3; deimination in arginine 161 only found in component C3; deamidation of glutamine 120 was only observed in C3. All four deiminated arginines and one acetylated lysine were first experimentally revealed in this study for bovine MBP. Mascot database searching combined with de novo sequence analysis of rattlesnake MBP provided more than 85% sequence coverage. A few PTMs were also revealed in rattlesnake MBP: mono- and dimethylated Arg, protein N-terminal acetylation, and deiminated Arg. Overall, snake MBP was found to undergo less modification than bovine MBP on the basis of the mass heterogeneity of the intact protein, the bottom-up structure analysis, and the limited complexity of rattlesnake MBP chromatography. The combined data from this study and information from previous studies extend the known MBP PTMs, and PTMs unique to higher vertebrates are proposed.
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Affiliation(s)
- Chunchao Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109
| | - Angela K. Walker
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109
| | - Robert Zand
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109
- Department of Macromolecular Science and Engineering, University of Michigan, Ann Arbor, MI 48109
| | - Mario A Moscarello
- Department of Molecular Structure, Hospital for Sick Children, Toronto, Canada
| | - Jerry Mingtao Yan
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109
| | - Philip C Andrews
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109
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Potential role of peptidylarginine deiminase enzymes and protein citrullination in cancer pathogenesis. Biochem Res Int 2012; 2012:895343. [PMID: 23019525 PMCID: PMC3457611 DOI: 10.1155/2012/895343] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 07/31/2012] [Accepted: 08/09/2012] [Indexed: 11/18/2022] Open
Abstract
The peptidylarginine deiminases (PADs) are a family of posttranslational modification enzymes that catalyze the conversion of positively charged protein-bound arginine and methylarginine residues to the uncharged, nonstandard amino acid citrulline. This enzymatic activity is referred to as citrullination or, alternatively, deimination. Citrullination can significantly affect biochemical pathways by altering the structure and function of target proteins. Five mammalian PAD family members (PADs 1–4 and 6) have been described and show tissue-specific distribution. Recent reviews on PADs have focused on their role in autoimmune diseases. Here, we will discuss the potential role of PADs in tumor progression and tumor-associated inflammation. In the context of cancer, increasing clinical evidence suggests that PAD4 (and possibly PAD2) has important roles in tumor progression. The link between PADs and cancer is strengthened by recent findings showing that treatment of cell lines and mice with PAD inhibitors significantly suppresses tumor growth and, interestingly, inflammatory symptoms. At the molecular level, transcription factors, coregulators, and histones are functional targets for citrullination by PADs, and citrullination of these targets can affect gene expression in multiple tumor cell lines. Next generation isozyme-specific PAD inhibitors may have therapeutic potential to regulate both the inflammatory tumor microenvironment and tumor cell growth.
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Stoeckle C, Tolosa E. Antigen processing and presentation in multiple sclerosis. Results Probl Cell Differ 2010; 51:149-72. [PMID: 19582405 DOI: 10.1007/400_2009_22] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
CD4(+) T cells play a central role in the pathogenesis of multiple sclerosis (MS). Generation, activation and effector function of these cells crucially depends on their interaction with MHC II-peptide complexes displayed by antigen presenting cells (APC). Processing and presentation of self antigens by different APC therefore influences the disease course at all stages. Selection by thymic APC leads to the generation of autoreactive T cells, which can be activated by peripheral APC. Reactivation by central nervous system APC leads to the initiation of the inflammatory response resulting in demyelination. In this review we will focus on how MHC class II antigenic epitopes are created by different APC from the thymus, the periphery and from the brain, and will discuss the relevance of the balance between creation and destruction of such epitopes in the context of MS. A solid understanding of these processes offers the possibility for designing future therapeutic strategies.
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Affiliation(s)
- Christina Stoeckle
- Department of General Neurology, Hertie Institute for Clinical Brain Research, Otfried-Mueller-Str. 27, 72076, Tuebingen, Germany.
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Karsdal MA, Henriksen K, Leeming DJ, Woodworth T, Vassiliadis E, Bay-Jensen AC. Novel combinations of Post-Translational Modification (PTM) neo-epitopes provide tissue-specific biochemical markers—are they the cause or the consequence of the disease? Clin Biochem 2010; 43:793-804. [DOI: 10.1016/j.clinbiochem.2010.03.015] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 03/22/2010] [Accepted: 03/28/2010] [Indexed: 12/31/2022]
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Méchin MC, Sebbag M, Arnaud J, Nachat R, Foulquier C, Adoue V, Coudane F, Duplan H, Schmitt AM, Chavanas S, Guerrin M, Serre G, Simon M. Update on peptidylarginine deiminases and deimination in skin physiology and severe human diseases. Int J Cosmet Sci 2010; 29:147-68. [PMID: 18489346 DOI: 10.1111/j.1467-2494.2007.00377.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Deimination (or citrullination) is a recently described post-translational modification, but its consequences are not yet well understood. It is catalysed by peptidylarginine deiminases (PADs). These enzymes transform arginyl residues involved in a peptidyl link into citrullyl residues in a calcium-dependent manner. Several PAD substrates have already been identified like filaggrin and keratins K1 and K10 in the epidermis, trichohyalin in hair follicles, but also ubiquitous proteins like histones. PADs act in a large panel of physiological functions as cellular differentiation or gene regulation. It has been suggested that deimination plays a role in many major diseases such as rheumatoid arthritis, multiple sclerosis, Alzheimer's disease and psoriasis. Five human genes (PADIs), encoding five highly conserved paralogous enzymes (PAD1-4 and 6), have been characterized. These genes are clustered in a single locus, at 1p35-36 in man. Only PAD1-3 are expressed in human epidermis. PADs seem to be controlled at transcriptional, translational and activity levels and they present particular substrate specificities. In this review, we shall discuss these main biochemical, genetic and functional aspects of PADs together with their pathophysiological implications.
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Affiliation(s)
- M-C Méchin
- University of Toulouse III, UMR5165, Institut Fédératif de Recherche Claude de Préval, Toulouse, France.
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Uysal H, Nandakumar KS, Kessel C, Haag S, Carlsen S, Burkhardt H, Holmdahl R. Antibodies to citrullinated proteins: molecular interactions and arthritogenicity. Immunol Rev 2010; 233:9-33. [DOI: 10.1111/j.0105-2896.2009.00853.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Deraos G, Chatzantoni K, Matsoukas MT, Tselios T, Deraos S, Katsara M, Papathanasopoulos P, Vynios D, Apostolopoulos V, Mouzaki A, Matsoukas J. Citrullination of Linear and Cyclic Altered Peptide Ligands from Myelin Basic Protein (MBP87−99) Epitope Elicits a Th1 Polarized Response by T Cells Isolated from Multiple Sclerosis Patients: Implications in Triggering Disease. J Med Chem 2008; 51:7834-42. [DOI: 10.1021/jm800891n] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- George Deraos
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Kokona Chatzantoni
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Minos-Timotheos Matsoukas
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Theodore Tselios
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Spyros Deraos
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Maria Katsara
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Panagiotis Papathanasopoulos
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Demitrios Vynios
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Vasso Apostolopoulos
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - Athanasia Mouzaki
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
| | - John Matsoukas
- Department of Chemistry, University of Patras, Patras 26500, Greece, Division of Hematology, Department of Internal Medicine, Medical School, University of Patras, Patras 26110, Greece, Neurology Clinic, Medical School and University Hospital, University of Patras, Patras 26500, Greece, and Immunology and Vaccine Laboratory, Burnet Institute (Austin Campus), Heidelberg, Victoria 3084, Australia
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Myelin localization of peptidylarginine deiminases 2 and 4: comparison of PAD2 and PAD4 activities. J Transl Med 2008; 88:354-64. [PMID: 18227806 DOI: 10.1038/labinvest.3700748] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
An understanding of the structure and composition of the myelin sheath is essential to understand the pathogenesis of demyelinating diseases such as multiple sclerosis (MS). The presence of citrulline in myelin proteins in particular myelin basic protein (MBP) causes an important change in myelin structure, which destabilizes myelin. The peptidylarginine deiminases (PADs) are responsible for converting arginine in proteins to citrulline. Two of these, PAD2 and PAD4, were localized to the myelin sheath by immunogold electron microscopy. Deimination of MBP by the recombinant forms of these enzymes showed that it was extensive, that is, PAD2 deiminated 18 of 19 arginyl residues in MBP, whereas PAD4 deiminated 14 of 19 residues. In the absence of PAD2 (the PAD2-knockout mouse) PAD4 remained active with limited deimination of arginyl residues. In myelin isolated from patients with MS, the amounts of both PAD2 and PAD4 enzymes were increased compared with that in normals, and the citrullinated proteins were also increased. These data support the view that an increase in citrullinated proteins resulting from increased PAD2 and 4 is an important change in the pathogenesis of MS.
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Musse AA, Harauz G. Molecular "negativity" may underlie multiple sclerosis: role of the myelin basic protein family in the pathogenesis of MS. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2007; 79:149-72. [PMID: 17531841 DOI: 10.1016/s0074-7742(07)79007-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Myelin basic protein (MBP) binds to negatively charged lipids on the cytosolic surface of oligodendrocyte membranes and is responsible for adhesion of these surfaces in the multilayered myelin sheath. The pattern of extensive posttranslational modifications of MBP is dynamic during normal central nervous system development and during myelin degeneration in multiple sclerosis (MS), affecting its interactions with the myelin membranes and other proteins. In particular, the degree of deimination (or citrullination) of MBP is correlated with the severity of MS, and may represent a primary defect that precedes neurodegeneration due to autoimmune attack. That MBP deimination also affects topological accessibility of an otherwise partially buried immunodominant epitope of the protein indicates that this modification may play a major role in the autoimmune pathogenesis of the disease. In this chapter, we describe the structural and functional consequences of MBP deimination in healthy and diseased myelin.
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Affiliation(s)
- Abdiwahab A Musse
- Department of Molecular and Cellular Biology, Biophysics Interdepartmental Group, University of Guelph, Ontario N1G 2W1, Canada
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DeBruin LS, Haines JD, Bienzle D, Harauz G. Partitioning of myelin basic protein into membrane microdomains in a spontaneously demyelinating mouse model for multiple sclerosisThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease. Biochem Cell Biol 2006; 84:993-1005. [PMID: 17215885 DOI: 10.1139/o06-180] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We have characterized the lipid rafts in myelin from a spontaneously demyelinating mouse line (ND4), and from control mice (CD1 background), as a function of age and severity of disease. Myelin was isolated from the brains of CD1 and ND4 mice at various ages, and cold lysed with 1.5% CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulphonate). The lysate was separated by low-speed centrifugation into supernatant and pellet fractions, which were characterized by Western blotting for myelin basic protein (MBP) isoforms and their post-translationally modified variants. We found that, with maturation and with disease progression, there was a specific redistribution of the 14–21.5 kDa MBP isoforms (classic exon-II-containing vs exon-II-lacking) and phosphorylated forms into the supernatant and pellet. Further fractionation of the supernatant to yield detergent-resistant membranes (DRMs), representing coalesced lipid rafts, showed these to be highly enriched in exon-II-lacking MBP isoforms, and deficient in methylated MBP variants, in mice of both genotypes. The DRMs from the ND4 mice appeared to be enriched in MBP phosphorylated by MAP kinase at Thr95 (murine 18.5 kDa numbering). These studies indicate that different splice isoforms and post-translationally modified charge variants of MBP are targeted to different microdomains in the myelin membrane, implying multifunctionality of this protein family in myelin maintenance.
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Affiliation(s)
- Lillian S DeBruin
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
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Harauz G, Musse AA. A Tale of Two Citrullines—Structural and Functional Aspects of Myelin Basic Protein Deimination in Health and Disease. Neurochem Res 2006; 32:137-58. [PMID: 16900293 DOI: 10.1007/s11064-006-9108-9] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2006] [Indexed: 02/03/2023]
Abstract
Myelin basic protein (MBP) binds to negatively charged lipids on the cytosolic surface of oligodendrocyte membranes and is responsible for adhesion of these surfaces in the multilayered myelin sheath. The pattern of extensive post-translational modifications of MBP is dynamic during normal central nervous system (CNS) development and during myelin degeneration in multiple sclerosis (MS), affecting its interactions with the myelin membranes and with other molecules. In particular, the degree of deimination (or citrullination) of MBP is correlated with the severity of MS, and may represent a primary defect that precedes neurodegeneration due to autoimmune attack. That the degree of MBP deimination is also high in early CNS development indicates that this modification plays major physiological roles in myelin assembly. In this review, we describe the structural and functional consequences of MBP deimination in healthy and diseased myelin.
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Affiliation(s)
- George Harauz
- Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, ON, Canada, N1G 2W1.
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Knipp M. How to Control NO Production in Cells: Nω,Nω-Dimethyl-L-Arginine Dimethylaminohydrolase as a Novel Drug Target. Chembiochem 2006; 7:879-89. [PMID: 16680784 DOI: 10.1002/cbic.200500527] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Markus Knipp
- Department of Chemistry, University of Arizona, 1306 East University Boulevard, Tucson, AZ 85721-0041, USA.
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György B, Tóth E, Tarcsa E, Falus A, Buzás EI. Citrullination: a posttranslational modification in health and disease. Int J Biochem Cell Biol 2006; 38:1662-77. [PMID: 16730216 DOI: 10.1016/j.biocel.2006.03.008] [Citation(s) in RCA: 338] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 03/13/2006] [Accepted: 03/14/2006] [Indexed: 11/29/2022]
Abstract
Posttranslational modifications are chemical changes to proteins that take place after synthesis. One such modification, peptidylarginine to peptidylcitrulline conversion, catalysed by peptidylarginine deiminases, has recently received significant interest in biomedicine. Introduction of citrulline dramatically changes the structure and function of proteins. It has been implicated in several physiological and pathological processes. Physiological processes include epithelial terminal differentiation, gene expression regulation, and apoptosis. Rheumatoid arthritis, multiple sclerosis, and Alzheimer's disease are examples of human diseases where protein citrullination involvement has been demonstrated. In this review, we discuss our current understanding on the importance of protein deimination in these processes. We describe the enzymes catalyzing the reaction, as well as their known protein substrates. We review the citrullinated peptide epitopes that are proposed as disease markers, specifically recognized in certain human autoimmune disorders. The potential autopathogenic role of citrullinated epitopes is also discussed.
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Affiliation(s)
- Bence György
- Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, Hungary
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Musse AA, Boggs JM, Harauz G. Deimination of membrane-bound myelin basic protein in multiple sclerosis exposes an immunodominant epitope. Proc Natl Acad Sci U S A 2006; 103:4422-7. [PMID: 16537438 PMCID: PMC1450187 DOI: 10.1073/pnas.0509158103] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The degradation of myelin in the CNS is the hallmark of multiple sclerosis. Reduction in the net positive charge of myelin basic protein (MBP), through deimination, correlates strongly with disease severity and may mediate myelin instability and loss of compaction. Using Cys scanning, spin labeling, EPR spectroscopy, and site-specific proteolysis, we show that in the membrane-bound state the primary immunodominant epitope, V83-T92, of the less cationic recombinant murine MBP C8 mimic (rmC8) forms a more highly surface-exposed and shorter amphipathic alpha-helix than in the unmodified form, recombinant murine MBP C1 mimic (rmC1), analogous to the most cationic and abundant isomer of MBP in normal myelin. Moreover, cathepsin D digested lipid-associated rmC8 3-fold faster than rmC1, and cleavage at F86-F87 occurred more readily in rmC8 than rmC1. These findings suggest a mechanism for initial loss of myelin stability and the autoimmune pathogenesis of multiple sclerosis.
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Affiliation(s)
- Abdiwahab A. Musse
- *Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, Guelph, ON, Canada N1G 2W1
| | - Joan M. Boggs
- Department of Structural Biology and Biochemistry, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8; and
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada M5G 1L5
| | - George Harauz
- *Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, Guelph, ON, Canada N1G 2W1
- To whom correspondence should be addressed. E-mail:
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3 Diverse roles of protein arginine methyltransferases. PROTEIN METHYLTRANSFERASES 2006; 24:51-103. [DOI: 10.1016/s1874-6047(06)80005-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Abstract
Multiple sclerosis (MS) is an autoimmune disease associated with chronic inflammatory demyelination of the central nervous system in genetically susceptible individuals. Because of the disease complexity and heterogeneity, its pathogenesis remains unknown despite extensive research efforts, and specific effective treatments have not yet been developed. Peptide-based research has been important in attempts to unravel particular aspects of this complex disease, including the characterization of the different molecular mechanisms of MS, with the goal of providing useful products for immune-mediated therapies. In fact, in the past decade, peptide-based research has been predominant in research aimed to identify and/or develop target antigens as synthetic probes for specific biomarkers as well as innovative immunomodulating therapies. This review presents an overview of the contributions of peptide science to MS research and discusses future directions of peptide-based investigations.
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Affiliation(s)
- Maria Claudia Alcaro
- Laboratory of Peptide and Protein Chemistry and Biology, Dipartimento di Chimica Organica, University of Firenze, Polo Scientifico, via della Lastruccia 13, I-50019 Sesto Fiorentino (FI), Italy
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McBride AE, Cook JT, Stemmler EA, Rutledge KL, McGrath KA, Rubens JA. Arginine Methylation of Yeast mRNA-binding Protein Npl3 Directly Affects Its Function, Nuclear Export, and Intranuclear Protein Interactions. J Biol Chem 2005; 280:30888-98. [PMID: 15998636 DOI: 10.1074/jbc.m505831200] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Arginine methylation can affect both nucleocytoplasmic transport and protein-protein interactions of RNA-binding proteins. These effects are seen in cells that lack the yeast hnRNP methyltransferase (HMT1), raising the question of whether effects on specific proteins are direct or indirect. The presence of multiple arginines in individual methylated proteins also raises the question of whether overall methylation or methylation of a subset of arginines affects protein function. We have used the yeast mRNA-binding protein Npl3 to address these questions in vivo. Matrix-assisted laser desorption/ionization Fourier transform mass spectrometry was used to identify 17 methylated arginines in Npl3 purified from yeast: whereas 10 Arg-Gly-Gly (RGG) tripeptides were exclusively dimethylated, variable levels of methylation were found for 5 RGG and 2 RG motif arginines. We constructed a set of Npl3 proteins in which subsets of the RGG arginines were mutated to lysine. Expression of these mutant proteins as the sole form of Npl3 specifically affected growth of a strain that requires Hmt1. Although decreased growth generally correlated with increased numbers of Arg-to-Lys mutations, lysine substitutions in the N terminus of the RGG domain showed more severe effects. Npl3 with all 15 RGG arginines mutated to lysine exited the nucleus independent of Hmt1, indicating a direct effect of methylation on Npl3 transport. These mutations also resulted in a decreased, methylation-independent interaction of Npl3 with transcription elongation factor Tho2 and inhibited Npl3 self-association. These results support a model in which arginine methylation facilitates Npl3 export directly by weakening contacts with nuclear proteins.
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Affiliation(s)
- Anne E McBride
- Department of Biology, Bowdoin College, Brunswick, Maine 04011, USA.
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Abstract
Alterations in amino acid sequence can generate neo-epitopes from self proteins, causing autoaggressive immune attack. There is a range of possible post-translational modifications (PTMs) of mammalian proteins that can allow immune recognition of neo-self epitopes. These effects can vary from overt increase in affinity of MHC or T-cell receptor binding, to more subtle effects on the activity of proteolytic enzymes involved in antigen processing. Furthermore, intriguing insights into how the complex interactions between inflammation, enzyme activity and protein modification can direct self recognition are beginning to be unearthed.
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Affiliation(s)
- Stephen M Anderton
- University of Edinburgh, Institute of Immunology and Infection Research, School of Biological Sciences, Kings Buildings, West Mains Road, Edinburgh, EH9 3JT, UK.
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Kubota K, Yoneyama-Takazawa T, Ichikawa K. Determination of sites citrullinated by peptidylarginine deiminase using 18O stable isotope labeling and mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2005; 19:683-688. [PMID: 15700232 DOI: 10.1002/rcm.1842] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Peptidylarginine deiminase (PADI) is an enzyme which catalyzes conversion of arginine residues into citrulline residues in proteins. Citrullination is known to be related to autoimmune diseases including rheumatoid arthritis. Previous work in this laboratory succeeded in identifying citrullinated sites of human fibrinogen by mass spectrometry, but discrimination between citrullination and deamidation of asparagines and glutamine required time-consuming and labor-intensive inspection of tandem mass spectra. In this work a stable isotope is utilized to improve on a previous method for the determination of citrullinated sites by mass spectrometry. Since an oxygen atom is incorporated into the citrulline residue from H(2)O in citrullination by PADI, peptides citrullinated in 50% H(2)(18)O would show a characteristic isotope distribution different from natural abundance, and thus determination of citrullinated sites is expected to be much easier. To verify the utility of this new method, the sites of citrullination of human fibrinogen by human PADI4 were investigated using 50% H(2)(18)O. Compared with the previous method, this new method identified citrullinated sites more easily and effectively, while both the determined citrullinated sites and protein sequence coverage were unaltered.
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Affiliation(s)
- Kazuishi Kubota
- Biomedical Research Laboratories, Sankyo Co., Ltd., Shinagawa-ku, Tokyo 140-8710, Japan.
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Harauz G, Ishiyama N, Hill CMD, Bates IR, Libich DS, Farès C. Myelin basic protein-diverse conformational states of an intrinsically unstructured protein and its roles in myelin assembly and multiple sclerosis. Micron 2004; 35:503-42. [PMID: 15219899 DOI: 10.1016/j.micron.2004.04.005] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The 18.5 kDa isoform of myelin basic protein (MBP) is a major component of the myelin sheath in the central nervous system of higher vertebrates, and a member of a larger family of proteins with a multiplicity of forms and post-translational modifications (PTMs). The 18.5 kDa protein is the exemplar of the family, being most abundant in adult myelin, and thus the most-studied. It is peripherally membrane-associated, but has generally been investigated in isolated form. MBP is an 'intrinsically unstructured' protein with a high proportion (approximately 75%) of random coil, but postulated to have core elements of beta-sheet and alpha-helix. We review here the properties of the MBP family, especially of the 18.5 kDa isoform, and discuss how its three-dimensional (3D) structure may be resolved by direct techniques available to us, viz., X-ray and electron crystallography, and solution and solid-state NMR spectrometry. In particular, we emphasise that creating an appropriate environment in which the protein can adopt a physiologically relevant fold is crucial to such endeavours. By solving the 3D structure of 18.5 kDa MBP and the effects of PTMs, we will attain a better understanding of myelin architecture, and of the molecular mechanisms that transpire in demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- George Harauz
- Department of Molecular Biology and Genetics, Biophysics Interdepartmental Group, University of Guelph, Room 230, Axelrod Building, 50 Stone Road East, Guelph, Ont., Canada N1G 2W1.
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Shanshiashvili LV, Suknidze NC, Machaidze GG, Mikeladze DG, Ramsden JJ. Adhesion and clustering of charge isomers of myelin basic protein at model myelin membranes. Arch Biochem Biophys 2003; 419:170-7. [PMID: 14592460 DOI: 10.1016/j.abb.2003.09.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The association of myelin basic protein charge isomers with the lipid part of the myelin membrane was investigated at the microscopic (molecular) level in a model membrane system, using optical waveguide lightmode spectrometry to determine with high precision the kinetics of association and dissociation to planar phospholipid membranes under controlled hydrodynamic conditions and over a range of protein concentrations. Detailed analysis of the data revealed a rich and intricate behaviour and clearly showed that the membrane protein affinity is characterized by at least four independent parameters: (i) the association rate coefficient characterizing the protein-membrane interaction energy as the protein approaches the fluid-membrane interface; (ii) the protein-membrane adhesion, i.e., the probability that it will remain at the membrane after arrival; (iii) the protein conformation at the membrane; and (iv) the protein's tendency to cluster at the membrane. Some of these parameters varied in characteristic ways as the bulk solution concentration of the protein was varied, giving further clues to the detailed molecular comportment of the protein. The parameters and their characteristic variations with bulk concentration were markedly different for the different isomers. Implications of these results for neurological disorders involving demyelination, such as multiple sclerosis, are discussed.
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Affiliation(s)
- L V Shanshiashvili
- I.S. Beritashvili Institute of Physiology, Georgian Academy of Sciences, Tbilisi, Georgia
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Libich DS, Hill CM, Bates IR, Hallett FR, Armstrong S, Siemiarczuk A, Harauz G. Interaction of the 18.5-kD isoform of myelin basic protein with Ca2+ -calmodulin: effects of deimination assessed by intrinsic Trp fluorescence spectroscopy, dynamic light scattering, and circular dichroism. Protein Sci 2003; 12:1507-21. [PMID: 12824496 PMCID: PMC2323942 DOI: 10.1110/ps.0303603] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The effects of deimination (conversion of arginyl to citrullinyl residues) of myelin basic protein (MBP) on its binding to calmodulin (CaM) have been examined. Four species of MBP were investigated: unmodified recombinant murine MBP (rmMBP-Cit(0)), an engineered protein with six quasi-citrullinyl (i.e., glutaminyl) residues per molecule (rmMBP-qCit(6)), human component C1 (hMBP-Cit(0)), and human component C8 (hMBP-Cit(6)), both obtained from a patient with multiple sclerosis (MS). Both rmMBP-Cit(0) and hMBP-Cit(0) bound CaM in a Ca(2+)-dependent manner and primarily in a 1:1 stoichiometry, which was verified by dynamic light scattering. Circular dichroic spectroscopy was unable to detect any changes in secondary structure in MBP upon CaM-binding. Inherent Trp fluorescence spectroscopy and a single-site binding model were used to determine the dissociation constants: K(d) = 144 +/- 76 nM for rmMBP-Cit(0), and K(d) = 42 +/- 15 nM for hMBP-Cit(0). For rmMBP-qCit(6) and hMBP-Cit(6), the changes in fluorescence were suggestive of a two-site interaction, although the dissociation constants could not be accurately determined. These results can be explained by a local conformational change induced in MBP by deimination, exposing a second binding site with a weaker association with CaM, or by the existence of several conformers of deiminated MBP. Titration with the collisional quencher acrylamide, and steady-state and lifetime measurements of the fluorescence at 340 nm, showed both dynamic and static components to the quenching, and differences between the unmodified and deiminated proteins that were also consistent with a local conformational change due to deimination.
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Affiliation(s)
- David S. Libich
- Department of Molecular Biology and Genetics, and Biophysics Interdepartmental Group, and
| | - Christopher M.D. Hill
- Department of Molecular Biology and Genetics, and Biophysics Interdepartmental Group, and
| | - Ian R. Bates
- Department of Molecular Biology and Genetics, and Biophysics Interdepartmental Group, and
| | - F. Ross Hallett
- Department of Physics, and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Souzan Armstrong
- Photon Technology International, London, Ontario N6E 2S8, Canada
| | | | - George Harauz
- Department of Molecular Biology and Genetics, and Biophysics Interdepartmental Group, and
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50
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Kim JK, Mastronardi FG, Wood DD, Lubman DM, Zand R, Moscarello MA. Multiple sclerosis: an important role for post-translational modifications of myelin basic protein in pathogenesis. Mol Cell Proteomics 2003; 2:453-62. [PMID: 12832457 DOI: 10.1074/mcp.m200050-mcp200] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myelin basic protein (MBP) represents a candidate autoantigen in multiple sclerosis (MS). We isolated MBP from normal and MS human white matter and purified six components (charge isomers) to compare the post-translational modifications on each. The sites and extent of methylation, deimination, and phosphorylation were documented for all tryptic peptides by mass spectrometry. We found that mono and dimethylated arginine 107 was increased in MS samples; deimination of arginine occurred at a number of sites and was elevated in MS; phosphorylation was observed in 10 peptides in normal samples but was greatly reduced or absent in most peptides from MS samples. Data obtained with MBP isolated from fresh brain obtained from a spontaneously demyelinating mouse model supported the view that the changes observed in human brain were probably related to pathogenesis of demyelination, i.e. we found decreased phosphorylation and decreased amounts of glycogen synthesis kinase in brain homogenates using specific antibodies. This study represents the first to define post-translational modifications in demyelinating disease and suggest an important role in pathogenesis.
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Affiliation(s)
- J K Kim
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
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