1
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Fuladi S, McGuinness S, Khalili-Araghi F. Role of TM3 in claudin-15 strand flexibility: A molecular dynamics study. Front Mol Biosci 2022; 9:964877. [PMID: 36250014 PMCID: PMC9557151 DOI: 10.3389/fmolb.2022.964877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
Claudins are cell-cell adhesion proteins within tight junctions that connect epithelial cells together. Claudins polymerize into a network of strand-like structures within the membrane of adjoining cells and create ion channels that control paracellular permeability to water and small molecules. Tight junction morphology and barrier function is tissue specific and regulated by claudin subtypes. Here, we present a molecular dynamics study of claudin-15 strands within lipid membranes and the role of a single-point mutation (A134P) on the third transmembrane helix (TM3) of claudin-15 in determining the morphology of the strand. Our results indicate that the A134P mutation significantly affects the lateral flexibility of the strands, increasing the persistence length of claudin-15 strands by a factor of three. Analyses of claudin-claudin contact in our μsecond-long trajectories show that the mutation does not alter the intermolecular contacts (interfaces) between claudins. However, the dynamics and frequency of interfacial contacts are significantly affected. The A134P mutation introduces a kink in TM3 of claudin-15 similar to the one observed in claudin-3 crystal structure. The kink on TM3 skews the rotational flexibility of the claudins in the strands and limits their fluctuation in one direction. This asymmetric movement in the context of the double rows reduces the lateral flexibility of the strand and leads to higher persistence lengths of the mutant.
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Affiliation(s)
- Shadi Fuladi
- Department of Physics, University of Illinois at Chicago, Chicago, IL, United States
| | - Sarah McGuinness
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Fatemeh Khalili-Araghi
- Department of Physics, University of Illinois at Chicago, Chicago, IL, United States
- *Correspondence: Fatemeh Khalili-Araghi,
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2
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Piontek J, Krug SM, Protze J, Krause G, Fromm M. Molecular architecture and assembly of the tight junction backbone. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183279. [PMID: 32224152 DOI: 10.1016/j.bbamem.2020.183279] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 12/18/2022]
Abstract
The functional and structural concept of tight junctions has developed after discovery of claudin and TAMP proteins. Many of these proteins contribute to epi- and endothelial barrier but some, in contrast, form paracellular channels. Claudins form the backbone of tight junction (TJ) strands whereas other proteins regulate TJ dynamics. The current joined double-row model of TJ strands and channels is crucially based on the linear alignment of claudin-15 in the crystal. Molecular dynamics simulations, protein docking, mutagenesis, cellular TJ reconstitution, and electron microscopy studies largely support stability and functionality of the model. Here, we summarize in silico and in vitro data about TJ strand assembly including comparison of claudin crystal structures and alternative models. Sequence comparisons, experimental and structural data substantiate differentiation of classic and non-classic claudins differing in motifs related to strand assembly. Classic claudins seem to share a similar mechanism of strand formation. Interface variations likely contribute to TJ strand flexibility. Combined in vitro/in silico studies are expected to elucidate mechanistic keys determining TJ regulation.
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Affiliation(s)
- Jörg Piontek
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany
| | - Susanne M Krug
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany
| | - Jonas Protze
- Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Gerd Krause
- Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany.
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3
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Assembly of Tight Junction Strands: Claudin-10b and Claudin-3 Form Homo-Tetrameric Building Blocks that Polymerise in a Channel-Independent Manner. J Mol Biol 2020; 432:2405-2427. [DOI: 10.1016/j.jmb.2020.02.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/12/2020] [Accepted: 02/28/2020] [Indexed: 02/03/2023]
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4
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Nakamura S, Irie K, Tanaka H, Nishikawa K, Suzuki H, Saitoh Y, Tamura A, Tsukita S, Fujiyoshi Y. Morphologic determinant of tight junctions revealed by claudin-3 structures. Nat Commun 2019; 10:816. [PMID: 30778075 PMCID: PMC6379431 DOI: 10.1038/s41467-019-08760-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 01/28/2019] [Indexed: 01/07/2023] Open
Abstract
Tight junction is a cell adhesion apparatus functioning as barrier and/or channel in the paracellular spaces of epithelia. Claudin is the major component of tight junction and polymerizes to form tight junction strands with various morphologies that may correlate with their functions. Here we present the crystal structure of mammalian claudin-3 at 3.6 Å resolution. The third transmembrane helix of claudin-3 is clearly bent compared with that of other subtypes. Structural analysis of additional two mutants with a single mutation representing other subtypes in the third helix indicates that this helix takes a bent or straight structure depending on the residue. The presence or absence of the helix bending changes the positions of residues related to claudin-claudin interactions and affects the morphology and adhesiveness of the tight junction strands. These results evoke a model for tight junction strand formation with different morphologies – straight or curvy strands – observed in native epithelia. The main components of tight junctions (TJ) are claudins that polymerize and form meshwork architectures called TJ strands. Here the authors present the 3.6 Å crystal structure of murine claudin-3 and show that residue P134 causes a bending of the third transmembrane helix which affects the morphology and adhesiveness of the TJ strands.
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Affiliation(s)
- Shun Nakamura
- Cellular and Structural Physiology Institute, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8601, Japan.,Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8601, Japan
| | - Katsumasa Irie
- Cellular and Structural Physiology Institute, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8601, Japan.,Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8601, Japan
| | - Hiroo Tanaka
- Laboratory of Biological Science, Graduate School of Frontier Biosciences and Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Kouki Nishikawa
- Cellular and Structural Physiology Institute, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8601, Japan
| | - Hiroshi Suzuki
- Cellular and Structural Physiology Institute, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8601, Japan.,Laboratory of Molecular Electron Microscopy, The Rockefeller University, New York, 10065, USA
| | - Yasunori Saitoh
- Cellular and Structural Physiology Institute, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8601, Japan.,Research Institute for Interdisciplinary Science, Okayama University, Tsushima Naka 3-1-1, Kita, Okayama, 700-8530, Japan
| | - Atsushi Tamura
- Laboratory of Biological Science, Graduate School of Frontier Biosciences and Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Sachiko Tsukita
- Laboratory of Biological Science, Graduate School of Frontier Biosciences and Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yoshinori Fujiyoshi
- Cellular and Structural Physiology Institute, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8601, Japan. .,CeSPIA Inc., 2-1-1 Otemachi, Chiyoda, Tokyo, 100-0004, Japan.
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5
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Claudin-1-Dependent Destabilization of the Blood-Brain Barrier in Chronic Stroke. J Neurosci 2018; 39:743-757. [PMID: 30504279 DOI: 10.1523/jneurosci.1432-18.2018] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 10/16/2018] [Accepted: 11/09/2018] [Indexed: 11/21/2022] Open
Abstract
Recent evidence suggests that blood-brain barrier (BBB) recovery and reestablishment of BBB impermeability after stroke is incomplete. This could influence stroke recovery, increase the risk of repeat stroke, and be a solid substrate for developing vascular dementia. Although accumulating evidence has defined morphological alterations and underlying mechanisms of tight junction (TJ) changes during BBB breakdown in acute stroke, very little is known about the type of alterations and mechanisms in BBB "leakage" found subacutely or chronically. The current study examined BBB structural alterations during the "BBB leakage" associated with the chronic phase of stroke in male mice and both genders of humans. We found significant upregulation of claudin-1 mRNA and protein, a nonspecific claudin for blood vessels, and downregulation in claudin-5 expression. Morphological and biochemical as well as fluorescence resonance energy transfer and fluorescence recovery after photobleaching analysis of postischemic brain endothelial cells and cells overexpressing claudin-1 indicated that newly synthesized claudin-1 was present on the cell membrane (∼45%), was incorporated into the TJ complex with established interaction with zonula occludens-1 (ZO-1), and was building homophilic cis- and trans-interactions. The appearance of claudin-1 in the TJ complex reduced claudin-5 strands (homophilic claudin-5 cis- and trans-interactions) and claudin-5/ZO-1 interaction affecting claudin-5 incorporation into the TJ complex. Moreover, claudin-1 induction was associated with an endothelial proinflammatory phenotype. Targeting claudin-1 with a specific C1C2 peptide improved brain endothelial barrier permeability and functional recovery in chronic stroke condition. This study highlights a potential "defect" in postischemic barrier formation that may underlie prolonged vessel leakiness.SIGNIFICANCE STATEMENT Although rarely expressed at the normal blood-brain barrier (BBB), claudin-1 is expressed in pathological conditions. Analyzing poststroke human and mouse blood microvessels we have identified that claudin-1 is highly expressed in leaky brain microvessels. Our results reveal that claudin-1 is incorporated in BBB tight junction complex, impeding BBB recovery and causing BBB leakiness during poststroke recovery. Targeting claudin-1 with a claudin-1 peptide improves brain endothelial barrier permeability and consequently functional neurological recovery after stroke.
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6
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Irudayanathan FJ, Wang X, Wang N, Willsey SR, Seddon IA, Nangia S. Self-Assembly Simulations of Classic Claudins—Insights into the Pore Structure, Selectivity, and Higher Order Complexes. J Phys Chem B 2018; 122:7463-7474. [DOI: 10.1021/acs.jpcb.8b03842] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Xiaoyi Wang
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Nan Wang
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Sarah R. Willsey
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Ian A. Seddon
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
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7
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Milatz S, Piontek J, Hempel C, Meoli L, Grohe C, Fromm A, Lee IFM, El-Athman R, Günzel D. Tight junction strand formation by claudin-10 isoforms and claudin-10a/-10b chimeras. Ann N Y Acad Sci 2017. [DOI: 10.1111/nyas.13393] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Susanne Milatz
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
- Institute of Physiology; Christian-Albrechts-University Kiel; Kiel Germany
| | - Jörg Piontek
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Caroline Hempel
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Luca Meoli
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Christoph Grohe
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Anja Fromm
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - In-Fah M. Lee
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Rukeia El-Athman
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
- Institute of Physiology; Christian-Albrechts-University Kiel; Kiel Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
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8
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Tight junctions of the proximal tubule and their channel proteins. Pflugers Arch 2017; 469:877-887. [DOI: 10.1007/s00424-017-2001-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 05/13/2017] [Accepted: 05/16/2017] [Indexed: 12/20/2022]
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9
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Piontek A, Rossa J, Protze J, Wolburg H, Hempel C, Günzel D, Krause G, Piontek J. Polar and charged extracellular residues conserved among barrier-forming claudins contribute to tight junction strand formation. Ann N Y Acad Sci 2017; 1397:143-156. [DOI: 10.1111/nyas.13341] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 02/26/2017] [Accepted: 03/01/2017] [Indexed: 01/09/2023]
Affiliation(s)
- Anna Piontek
- Leibniz-Institut für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Jan Rossa
- Leibniz-Institut für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Jonas Protze
- Leibniz-Institut für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Hartwig Wolburg
- Institute of Pathology and Neuropathology; University of Tübingen; Tübingen Germany
| | - Caroline Hempel
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Gerd Krause
- Leibniz-Institut für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Jörg Piontek
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
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10
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Luo H, Zhou DJ, Chen Z, Zhou QQ, Wu K, Tian K, Li ZW, Xiao ZL. Establishment and evaluation of an experimental rat model for high-altitude intestinal barrier injury. Exp Ther Med 2016; 13:475-482. [PMID: 28352318 PMCID: PMC5348649 DOI: 10.3892/etm.2016.4012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 10/28/2016] [Indexed: 01/19/2023] Open
Abstract
In the present study an experimental high-altitude intestinal barrier injury rat model was established by simulating an acute hypoxia environment, to provide an experimental basis to assess the pathogenesis, prevention and treatment of altitude sickness. A total of 70 healthy male Sprague-Dawley rats were divided into two groups: Control group (group C) and a high-altitude hypoxia group (group H). Following 2 days adaptation, the rats in group H were exposed to a simulated 4,000-m, high-altitude hypoxia environment for 3 days to establish the experimental model. To evaluate the model, bacterial translocation, serum lipopolysaccharide level, pathomorphology, ultrastructure and protein expression in rats were assessed. The results indicate that, compared with group C, the rate of bacterial translocation and the apoptotic index of intestinal epithelial cells were significantly higher in group H (P<0.01). Using a light microscope it was determined that the intestinal mucosa was thinner in group H, there were fewer epithelial cells present and the morphology was irregular. Observations with an electron microscope indicated that the intestinal epithelial cells in group H were injured, the spaces among intestinal villi were wider, the tight junctions among cells were open and lanthanum nitrate granules (from the fixing solution) had diffused into the intestinal mesenchyme. The expression of the tight junction protein occludin was also decreased in group H. Therefore, the methods applied in the present study enabled the establishment of a stable, high-altitude intestinal barrier injury model in rats.
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Affiliation(s)
- Han Luo
- Respiratory Department, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Dai-Jun Zhou
- The Fourth Institute of Field Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
| | - Zhang Chen
- Respiratory Department, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Qi-Quan Zhou
- High Altitude Military Medical Science Academy, Third Military Medical University, Chongqing 400038, P.R. China
| | - Kui Wu
- Respiratory Department, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Kun Tian
- Respiratory Department, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Zhi-Wei Li
- Respiratory Department, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
| | - Zhen-Liang Xiao
- Respiratory Department, Chengdu Military General Hospital, Chengdu, Sichuan 610083, P.R. China
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11
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Liu F, Koval M, Ranganathan S, Fanayan S, Hancock WS, Lundberg EK, Beavis RC, Lane L, Duek P, McQuade L, Kelleher NL, Baker MS. Systems Proteomics View of the Endogenous Human Claudin Protein Family. J Proteome Res 2016; 15:339-59. [PMID: 26680015 DOI: 10.1021/acs.jproteome.5b00769] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Claudins are the major transmembrane protein components of tight junctions in human endothelia and epithelia. Tissue-specific expression of claudin members suggests that this protein family is not only essential for sustaining the role of tight junctions in cell permeability control but also vital in organizing cell contact signaling by protein-protein interactions. How this protein family is collectively processed and regulated is key to understanding the role of junctional proteins in preserving cell identity and tissue integrity. The focus of this review is to first provide a brief overview of the functional context, on the basis of the extensive body of claudin biology research that has been thoroughly reviewed, for endogenous human claudin members and then ascertain existing and future proteomics techniques that may be applicable to systematically characterizing the chemical forms and interacting protein partners of this protein family in human. The ability to elucidate claudin-based signaling networks may provide new insight into cell development and differentiation programs that are crucial to tissue stability and manipulation.
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Affiliation(s)
| | - Michael Koval
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, and Department of Cell Biology, Emory University School of Medicine , 205 Whitehead Biomedical Research Building, 615 Michael Street, Atlanta, Georgia 30322, United States
| | | | | | - William S Hancock
- Barnett Institute and Department of Chemistry and Chemical Biology, Northeastern University , Boston, Massachusetts 02115, United States
| | - Emma K Lundberg
- SciLifeLab, School of Biotechnology, Royal Institute of Technology (KTH) , SE-171 21 Solna, Stockholm, Sweden
| | - Ronald C Beavis
- Department of Biochemistry and Medical Genetics, University of Manitoba , 744 Bannatyne Avenue, Winnipeg, Manitoba R3E 0W3, Canada
| | - Lydie Lane
- SIB-Swiss Institute of Bioinformatics , CMU - Rue Michel-Servet 1, 1211 Geneva, Switzerland
| | - Paula Duek
- SIB-Swiss Institute of Bioinformatics , CMU - Rue Michel-Servet 1, 1211 Geneva, Switzerland
| | | | - Neil L Kelleher
- Department of Chemistry, Department of Molecular Biosciences, and Proteomics Center of Excellence, Northwestern University , 2145 North Sheridan Road, Evanston, Illinois 60208, United States
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12
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Conrad MP, Piontek J, Günzel D, Fromm M, Krug SM. Molecular basis of claudin-17 anion selectivity. Cell Mol Life Sci 2016; 73:185-200. [PMID: 26194246 PMCID: PMC11108356 DOI: 10.1007/s00018-015-1987-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/23/2015] [Accepted: 07/09/2015] [Indexed: 01/09/2023]
Abstract
Claudin-17 is a paracellular channel-forming tight junction protein. Unlike the cation channels claudin-2 and -15, claudin-17 forms a distinct anion-selective channel. Aim of this study was to determine the molecular basis of channel formation and charge selectivity of this protein. To achieve this, residues located in the extracellular loops (ECL) 1 and 2 of claudin-17 were substituted, preferably those whose charges differed in claudin-17 and in claudin-2 or -15. The respective mutants were stably expressed in MDCK C7 cells and their ability to form charge-selective channels was analyzed by measuring ion permeabilities and transepithelial electrical resistance. The functional data were combined with homology modeling of the claudin-17 protomer using the structure of claudin-15 as template. In ECL1, K65, R31, E48, and E44 were found to be stronger involved in Cldn17 channel function than the clustered R45, R56, R59, and R61. For K65, not only charge but also stereochemical properties were crucial for formation of the anion-selective channel. In ECL2, both Y149 and H154 were found to contribute to constitution of the anion channel in a distinct manner. In conclusion, we provide insight into the molecular mechanism of the formation of charge- and size-selective paracellular ion channels. In detail, we propose a hydrophilic furrow in the claudin-17 protomer spanning from a gap between the ends of TM2 and TM3 along R31, E48, and Y67 to a gap between K65 and S68 lining the anion channel.
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Affiliation(s)
- Marcel P Conrad
- Institute of Clinical Physiology, Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Jörg Piontek
- Institute of Clinical Physiology, Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology, Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology, Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Susanne M Krug
- Institute of Clinical Physiology, Charité, Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203, Berlin, Germany.
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13
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Irudayanathan FJ, Trasatti JP, Karande P, Nangia S. Molecular Architecture of the Blood Brain Barrier Tight Junction Proteins–A Synergistic Computational and In Vitro Approach. J Phys Chem B 2015; 120:77-88. [DOI: 10.1021/acs.jpcb.5b09977] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
| | - John P. Trasatti
- Department
of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Pankaj Karande
- Department
of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Shikha Nangia
- Department
of Biomedical and Chemical Engineering, Syracuse University, Syracuse New York 13244, United States
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14
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Probing the cis-arrangement of prototype tight junction proteins claudin-1 and claudin-3. Biochem J 2015; 468:449-58. [DOI: 10.1042/bj20150148] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 04/07/2015] [Indexed: 11/17/2022]
Abstract
Claudins, tetraspan transmembrane proteins forming tight junction strands, regulate the paracellular pathway of epithelia. FRET experiments were carried out on claudin-1 and claudin-3 to determine strand architecture. Results are consistent with an antiparallel double-row arrangement within each membrane.
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15
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Assembly and function of claudins: Structure–function relationships based on homology models and crystal structures. Semin Cell Dev Biol 2015; 42:3-12. [DOI: 10.1016/j.semcdb.2015.04.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 01/12/2023]
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16
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Conceptual barriers to understanding physical barriers. Semin Cell Dev Biol 2015; 42:13-21. [PMID: 26003050 DOI: 10.1016/j.semcdb.2015.04.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 04/26/2015] [Indexed: 01/18/2023]
Abstract
The members of the large family of claudin proteins regulate ion and water flux across the tight junction. Many claudins, e.g. claudins 2 and 15, accomplish this by forming size- and charge-selective paracellular channels. Claudins also appear to be essential for genesis of tight junction strands and recruitment of other proteins to these sites. What is less clear is whether claudins form the paracellular seal. While this seal is defective when claudins are disrupted, some results, including ultrastructural and biochemical data, suggest that lipid structures are an important component of tight junction strands and may be responsible for the paracellular seal. This review highlights current understanding of claudin contributions to barrier function and tight junction structure and suggests a model by which claudins and other tight junction proteins can drive assembly and stabilization of a lipid-based strand structure.
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17
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Schlingmann B, Molina SA, Koval M. Claudins: Gatekeepers of lung epithelial function. Semin Cell Dev Biol 2015; 42:47-57. [PMID: 25951797 DOI: 10.1016/j.semcdb.2015.04.009] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 04/24/2015] [Indexed: 12/25/2022]
Abstract
The lung must maintain a proper barrier between airspaces and fluid filled tissues in order to maintain lung fluid balance. Central to maintaining lung fluid balance are epithelial cells which create a barrier to water and solutes. The barrier function of these cells is mainly provided by tight junction proteins known as claudins. Epithelial barrier function varies depending on the different needs within the segments of the respiratory tree. In the lower airways, fluid is required to maintain mucociliary clearance, whereas in the terminal alveolar airspaces a thin layer of surfactant enriched fluid lowers surface tension to prevent airspace collapse and is critical for gas exchange. As the epithelial cells within the segments of the respiratory tree differ, the composition of claudins found in these epithelial cells is also different. Among these differences is claudin-18 which is uniquely expressed by the alveolar epithelial cells. Other claudins, notably claudin-4 and claudin-7, are more ubiquitously expressed throughout the respiratory epithelium. Claudin-5 is expressed by both pulmonary epithelial and endothelial cells. Based on in vitro and in vivo model systems and histologic analysis of lungs from human patients, roles for specific claudins in maintaining barrier function and protecting the lung from the effects of acute injury and disease are being identified. One surprising finding is that claudin-18 and claudin-4 control lung cell phenotype and inflammation beyond simply maintaining a selective paracellular permeability barrier. This suggests claudins have more nuanced roles for the control of airway and alveolar physiology in the healthy and diseased lung.
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Affiliation(s)
- Barbara Schlingmann
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Samuel A Molina
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Michael Koval
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, United States.
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