101
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Shabardina V, Kramer C, Gerdes B, Braunger J, Cordes A, Schäfer J, Mey I, Grill D, Gerke V, Steinem C. Mode of Ezrin-Membrane Interaction as a Function of PIP2 Binding and Pseudophosphorylation. Biophys J 2017; 110:2710-2719. [PMID: 27332129 DOI: 10.1016/j.bpj.2016.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 04/14/2016] [Accepted: 05/05/2016] [Indexed: 12/28/2022] Open
Abstract
Ezrin, a protein of the ezrin, radixin, moesin (ERM) family, provides a regulated linkage between the plasma membrane and the cytoskeleton. The hallmark of this linkage is the activation of ezrin by phosphatidylinositol-4,5-bisphosphate (PIP2) binding and a threonine phosphorylation at position 567. To analyze the influence of these activating factors on the organization of ezrin on lipid membranes and the proposed concomitant oligomer-monomer transition, we made use of supported lipid bilayers in conjunction with atomic force microscopy and fluorescence microscopy. Bilayers doped with either PIP2 as the natural receptor lipid of ezrin or a Ni-nitrilotriacetic acid-equipped lipid to bind the proteins via their His6-tags to the lipid membrane were used to bind two different ezrin variants: ezrin wild-type and ezrin T567D mimicking the phosphorylated state. Using a combination of reflectometric interference spectroscopy, atomic force microscopy, and Förster resonance energy transfer experiments, we show that only the ezrin T567D mutant, upon binding to PIP2-containing bilayers, undergoes a remarkable conformational change, which we attribute to an opening of the conformation resulting in monomeric protein on the lipid bilayer.
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Affiliation(s)
- Victoria Shabardina
- Institute of Medical Biochemistry and Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Corinna Kramer
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Benjamin Gerdes
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Julia Braunger
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Andrea Cordes
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Jonas Schäfer
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Ingo Mey
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - David Grill
- Institute of Medical Biochemistry and Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry and Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany.
| | - Claudia Steinem
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; Göttingen Center for Molecular Biosciences, Göttingen, Germany.
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102
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Structure of Myo7b/USH1C complex suggests a general PDZ domain binding mode by MyTH4-FERM myosins. Proc Natl Acad Sci U S A 2017; 114:E3776-E3785. [PMID: 28439001 DOI: 10.1073/pnas.1702251114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Unconventional myosin 7a (Myo7a), myosin 7b (Myo7b), and myosin 15a (Myo15a) all contain MyTH4-FERM domains (myosin tail homology 4-band 4.1, ezrin, radixin, moesin; MF) in their cargo binding tails and are essential for the growth and function of microvilli and stereocilia. Numerous mutations have been identified in the MyTH4-FERM tandems of these myosins in patients suffering visual and hearing impairment. Although a number of MF domain binding partners have been identified, the molecular basis of interactions with the C-terminal MF domain (CMF) of these myosins remains poorly understood. Here we report the high-resolution crystal structure of Myo7b CMF in complex with the extended PDZ3 domain of USH1C (a.k.a., Harmonin), revealing a previously uncharacterized interaction mode both for MyTH4-FERM tandems and for PDZ domains. We predicted, based on the structure of the Myo7b CMF/USH1C PDZ3 complex, and verified that Myo7a CMF also binds to USH1C PDZ3 using a similar mode. The structure of the Myo7b CMF/USH1C PDZ complex provides mechanistic explanations for >20 deafness-causing mutations in Myo7a CMF. Taken together, these findings suggest that binding to PDZ domains, such as those from USH1C, PDZD7, and Whirlin, is a common property of CMFs of Myo7a, Myo7b, and Myo15a.
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103
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Pelaseyed T, Viswanatha R, Sauvanet C, Filter JJ, Goldberg ML, Bretscher A. Ezrin activation by LOK phosphorylation involves a PIP 2-dependent wedge mechanism. eLife 2017; 6. [PMID: 28430576 PMCID: PMC5400502 DOI: 10.7554/elife.22759] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/27/2017] [Indexed: 12/15/2022] Open
Abstract
How cells specify morphologically distinct plasma membrane domains is poorly understood. Prior work has shown that restriction of microvilli to the apical aspect of epithelial cells requires the localized activation of the membrane-F-actin linking protein ezrin. Using an in vitro system, we now define a multi-step process whereby the kinase LOK specifically phosphorylates ezrin to activate it. Binding of PIP2 to ezrin induces a conformational change permitting the insertion of the LOK C-terminal domain to wedge apart the membrane and F-actin-binding domains of ezrin. The N-terminal LOK kinase domain can then access a site 40 residues distal from the consensus sequence that collectively direct phosphorylation of the appropriate threonine residue. We suggest that this elaborate mechanism ensures that ezrin is only phosphorylated at the plasma membrane, and with high specificity by the apically localized kinase LOK. DOI:http://dx.doi.org/10.7554/eLife.22759.001
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Affiliation(s)
- Thaher Pelaseyed
- Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, United States.,Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Raghuvir Viswanatha
- Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, United States.,Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States.,Department of Genetics, Harvard Medical School, Boston, United States
| | - Cécile Sauvanet
- Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, United States.,Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Joshua J Filter
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Michael L Goldberg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Anthony Bretscher
- Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, United States.,Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
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104
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Li T, Niu X, Zhang X, Wang S, Liu Z. Recombinant Human IFNα-2b Response Promotes Vaginal Epithelial Cells Defense against Candida albicans. Front Microbiol 2017; 8:697. [PMID: 28473823 PMCID: PMC5397410 DOI: 10.3389/fmicb.2017.00697] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 04/05/2017] [Indexed: 12/17/2022] Open
Abstract
Classical antifungal drugs have been subjected to restrictions due to drug toxicity, drug resistance, bioavailability, and detrimental drug interactions. Type I interferon (IFN) exerts direct distinct immunostimulatory or immunomodulatory actions; however, little is known regarding the anti-fungal reactions of vaginal epithelial cells (VECs) induced by the type I IFN response. Therefore, in the present study, we evaluated the cytotoxic activity, immunocompetent cytokine responses, and non-B IgG production of the VK2/E6E7 VEC line following recombinant human IFN α-2b (rhIFNα-2b) treatment in response to Candida albicans. When treated with rhIFNα-2b, the production of IL-2, IL-4, and IL-17 were significantly up-regulated compared to the infected control cells (P < 0.05). Our scanning electron microscopy results revealed that C. albicans can invade VECs by inducing both endocytosis and active penetration. RhIFNα-2b was able to transform the VECs into a thallus and stretched pattern, promoting the fusion of filopodia to form a lamellipodium and enhancing the mobility and the repair capacity of the VECs. In addition, rhIFNα-2b could effectively inhibit the adhesion, hyphal formation, and proliferation of C. albicans. Collectively, these responses restored the immune function of the infected VECs against C. albicans in vitro, providing a theoretical basis for this novel treatment strategy.
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Affiliation(s)
- Ting Li
- Department of Obstetrics and Gynecology, Peking University First HospitalBeijing, China
| | - Xiaoxi Niu
- Department of Obstetrics and Gynecology, Peking University First HospitalBeijing, China
| | - Xu Zhang
- Laboratory of Electron Microscopy, Ultrastructural Pathology Center, Peking University First HospitalBeijing, China
| | - Suxia Wang
- Laboratory of Electron Microscopy, Ultrastructural Pathology Center, Peking University First HospitalBeijing, China
| | - Zhaohui Liu
- Department of Obstetrics and Gynecology, Peking University First HospitalBeijing, China
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105
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Jorgens DM, Inman JL, Wojcik M, Robertson C, Palsdottir H, Tsai WT, Huang H, Bruni-Cardoso A, López CS, Bissell MJ, Xu K, Auer M. Deep nuclear invaginations are linked to cytoskeletal filaments - integrated bioimaging of epithelial cells in 3D culture. J Cell Sci 2017; 130:177-189. [PMID: 27505896 PMCID: PMC5394780 DOI: 10.1242/jcs.190967] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 07/28/2016] [Indexed: 02/04/2023] Open
Abstract
The importance of context in regulation of gene expression is now an accepted principle; yet the mechanism by which the microenvironment communicates with the nucleus and chromatin in healthy tissues is poorly understood. A functional role for nuclear and cytoskeletal architecture is suggested by the phenotypic differences observed between epithelial and mesenchymal cells. Capitalizing on recent advances in cryogenic techniques, volume electron microscopy and super-resolution light microscopy, we studied human mammary epithelial cells in three-dimensional (3D) cultures forming growth-arrested acini. Intriguingly, we found deep nuclear invaginations and tunnels traversing the nucleus, encasing cytoskeletal actin and/or intermediate filaments, which connect to the outer nuclear envelope. The cytoskeleton is also connected both to other cells through desmosome adhesion complexes and to the extracellular matrix through hemidesmosomes. This finding supports a physical and/or mechanical link from the desmosomes and hemidesmosomes to the nucleus, which had previously been hypothesized but now is visualized for the first time. These unique structures, including the nuclear invaginations and the cytoskeletal connectivity to the cell nucleus, are consistent with a dynamic reciprocity between the nucleus and the outside of epithelial cells and tissues.
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Affiliation(s)
- Danielle M Jorgens
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS Donner, Berkeley, CA 94720, USA
- Department of Biomedical Engineering, Oregon Health and Science University, 3181 Sam Jackson Park Road, Portland, OR 97239, USA
| | - Jamie L Inman
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Michal Wojcik
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Claire Robertson
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Hildur Palsdottir
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS Donner, Berkeley, CA 94720, USA
| | - Wen-Ting Tsai
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS Donner, Berkeley, CA 94720, USA
| | - Haina Huang
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Alexandre Bruni-Cardoso
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry Instituto de Quimica, Universidade de Sao Paulo, Sao Paulo, 05508-000, Brazil
| | - Claudia S López
- Department of Biomedical Engineering, Oregon Health and Science University, 3181 Sam Jackson Park Road, Portland, OR 97239, USA
| | - Mina J Bissell
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ke Xu
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS Donner, Berkeley, CA 94720, USA
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Manfred Auer
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS Donner, Berkeley, CA 94720, USA
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106
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Sharma N, LaRusch J, Sosnay PR, Gottschalk LB, Lopez AP, Pellicore MJ, Evans T, Davis E, Atalar M, Na CH, Rosson GD, Belchis D, Milewski M, Pandey A, Cutting GR. A sequence upstream of canonical PDZ-binding motif within CFTR COOH-terminus enhances NHERF1 interaction. Am J Physiol Lung Cell Mol Physiol 2016; 311:L1170-L1182. [PMID: 27793802 PMCID: PMC5206395 DOI: 10.1152/ajplung.00363.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 10/18/2016] [Indexed: 01/10/2023] Open
Abstract
The development of cystic fibrosis transmembrane conductance regulator (CFTR) targeted therapy for cystic fibrosis has generated interest in maximizing membrane residence of mutant forms of CFTR by manipulating interactions with scaffold proteins, such as sodium/hydrogen exchange regulatory factor-1 (NHERF1). In this study, we explored whether COOH-terminal sequences in CFTR beyond the PDZ-binding motif influence its interaction with NHERF1. NHERF1 displayed minimal self-association in blot overlays (NHERF1, Kd = 1,382 ± 61.1 nM) at concentrations well above physiological levels, estimated at 240 nM from RNA-sequencing and 260 nM by liquid chromatography tandem mass spectrometry in sweat gland, a key site of CFTR function in vivo. However, NHERF1 oligomerized at considerably lower concentrations (10 nM) in the presence of the last 111 amino acids of CFTR (20 nM) in blot overlays and cross-linking assays and in coimmunoprecipitations using differently tagged versions of NHERF1. Deletion and alanine mutagenesis revealed that a six-amino acid sequence 1417EENKVR1422 and the terminal 1478TRL1480 (PDZ-binding motif) in the COOH-terminus were essential for the enhanced oligomerization of NHERF1. Full-length CFTR stably expressed in Madin-Darby canine kidney epithelial cells fostered NHERF1 oligomerization that was substantially reduced (∼5-fold) on alanine substitution of EEN, KVR, or EENKVR residues or deletion of the TRL motif. Confocal fluorescent microscopy revealed that the EENKVR and TRL sequences contribute to preferential localization of CFTR to the apical membrane. Together, these results indicate that COOH-terminal sequences mediate enhanced NHERF1 interaction and facilitate the localization of CFTR, a property that could be manipulated to stabilize mutant forms of CFTR at the apical surface to maximize the effect of CFTR-targeted therapeutics.
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Affiliation(s)
- Neeraj Sharma
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jessica LaRusch
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
- ARIEL Precision Medicine, Pittsburgh, Pennsylvania
| | - Patrick R Sosnay
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Laura B Gottschalk
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Andrea P Lopez
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Matthew J Pellicore
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Taylor Evans
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Emily Davis
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Melis Atalar
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chan-Hyun Na
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Gedge D Rosson
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Deborah Belchis
- Department of Surgical Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Michal Milewski
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Akhilesh Pandey
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Garry R Cutting
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland;
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107
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Freddo AM, Shoffner SK, Shao Y, Taniguchi K, Grosse AS, Guysinger MN, Wang S, Rudraraju S, Margolis B, Garikipati K, Schnell S, Gumucio DL. Coordination of signaling and tissue mechanics during morphogenesis of murine intestinal villi: a role for mitotic cell rounding. Integr Biol (Camb) 2016; 8:918-28. [PMID: 27476872 PMCID: PMC5021607 DOI: 10.1039/c6ib00046k] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Efficient digestion and absorption of nutrients by the intestine requires a very large apical surface area, a feature that is enhanced by the presence of villi, fingerlike epithelial projections that extend into the lumen. Prior to villus formation, the epithelium is a thick pseudostratified layer. In mice, villus formation begins at embryonic day (E)14.5, when clusters of mesenchymal cells form just beneath the thick epithelium. At this time, analysis of the flat lumenal surface reveals a regular pattern of short apical membrane invaginations that form in regions of the epithelium that lie in between the mesenchymal clusters. Apical invaginations begin in the proximal intestine and spread distally, deepening with time. Interestingly, mitotically rounded cells are frequently associated with these invaginations. These mitotic cells are located at the tips of the invaginating membrane (internalized within the epithelium), rather than adjacent to the apical surface. Further investigation of epithelial changes during membrane invagination reveals that epithelial cells located between mesenchymal clusters experience a circumferential compression, as epithelial cells above each cluster shorten and widen. Using a computational model, we examined whether such forces are sufficient to cause apical invaginations. Simulations and in vivo data reveal that proper apical membrane invagination involves intraepithelial compressive forces, mitotic cell rounding in the compressed regions and apico-basal contraction of the dividing cell. Together, these data establish a new model that explains how signaling events intersect with tissue forces to pattern apical membrane invaginations that define the villus boundaries.
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Affiliation(s)
- Andrew M Freddo
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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108
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Tavasoli M, Al-Momany A, Wang X, Li L, Edwards JC, Ballermann BJ. Both CLIC4 and CLIC5A activate ERM proteins in glomerular endothelium. Am J Physiol Renal Physiol 2016; 311:F945-F957. [PMID: 27582103 DOI: 10.1152/ajprenal.00353.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 08/25/2016] [Indexed: 01/17/2023] Open
Abstract
The chloride intracellular channel (CLIC) 5A is expressed at very high levels in renal glomeruli, in both endothelial cells (EC) and podocytes. CLIC5A stimulates Rac1- and phosphatidylinositol (4,5)-bisphosphate-dependent ERM (ezrin, radixin, moesin) activation. ERM proteins, in turn, function in lumen formation and in the development of actin-based cellular projections. In mice lacking CLIC5A, ERM phosphorylation is profoundly reduced in podocytes, but preserved in glomerular EC. Since glomerular EC also express CLIC4, we reasoned that, if CLIC4 activates ERM proteins like CLIC5A, then CLIC4 could compensate for the CLIC5A loss in glomerular EC. In glomeruli of CLIC5-deficient mice, CLIC4 expression was upregulated and colocalized with moesin and ezrin in glomerular EC, but not in podocytes. In cultured glomerular EC, CLIC4 silencing reduced ERM phosphorylation and cytoskeletal association, and expression of exogenous CLIC4 or CLIC5A rescued ERM de-phosphorylation due to CLIC4 silencing. In mice lacking either CLIC4 or CLIC5, ERM phosphorylation was retained in glomerular EC, but, in mice lacking both CLIC4 and CLIC5, glomerular EC ERM phosphorylation was profoundly reduced. Although glomerular EC fenestrae developed normally in dual CLIC4/CLIC5-deficient mice, the density of fenestrae declined substantially by 8 mo of age, along with the deposition of subendothelial electron-lucent material. The dual CLIC4/CLIC5-deficient mice developed spontaneous proteinuria, glomerular cell proliferation, and matrix deposition. Thus CLIC4 stimulates ERM activation and can compensate for CLIC5A in glomerular EC. The findings indicate that CLIC4/CLIC5A-mediated ERM activation is required for maintenance of the glomerular capillary architecture.
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Affiliation(s)
- Mahtab Tavasoli
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Abass Al-Momany
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; and
| | - Xin Wang
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Laiji Li
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - John C Edwards
- Department of Internal Medicine, St. Louis University, St. Louis, Missouri
| | - Barbara J Ballermann
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; .,Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; and
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109
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Chen Q, Wei T. Viral receptors of the gut: insect-borne propagative plant viruses of agricultural importance. CURRENT OPINION IN INSECT SCIENCE 2016; 16:9-13. [PMID: 27720057 DOI: 10.1016/j.cois.2016.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/25/2016] [Indexed: 06/06/2023]
Abstract
Insect-borne propagative plant viruses of agricultural importance are transmitted by sap-sucking insects. Although the infection routes of these viruses within the bodies of insect vectors are well established, cellular receptors on the microvilli, intercellular junctions, and basal lamina for mediating viral entry or spread in insect gut epithelium have not been well identified or characterized. Recent trends in the field are opening questions on how viruses exploit actin-based tubule motility to overcome insect gut epithelium barriers after viral entry in epithelium. Advances in insect cell lines, genome sequencing, reverse genetic systems and others not yet developed technologies are needed to find and characterize the counterpart receptors in vectors and to design strategies to interfere with viral transmission.
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Affiliation(s)
- Qian Chen
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China
| | - Taiyun Wei
- Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China.
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110
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Peña JF, Alié A, Richter DJ, Wang L, Funayama N, Nichols SA. Conserved expression of vertebrate microvillar gene homologs in choanocytes of freshwater sponges. EvoDevo 2016; 7:13. [PMID: 27413529 PMCID: PMC4942974 DOI: 10.1186/s13227-016-0050-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 06/28/2016] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND The microvillus is a versatile organelle that serves important functions in disparate animal cell types. However, from a molecular perspective, the microvillus has been well studied in only a few, predominantly vertebrate, contexts. Little is known about how differences in microvillar structure contribute to differences in function, and how these differences evolved. We sequenced the transcriptome of the freshwater sponge, Ephydatia muelleri, and examined the expression of vertebrate microvillar gene homologs in choanocytes-the only microvilli-bearing cell type present in sponges. Sponges offer a distant phylogenetic comparison with vertebrates, and choanocytes are central to discussions about early animal evolution due to their similarity with choanoflagellates, the single-celled sister lineage of modern animals. RESULTS We found that, from a genomic perspective, sponges have conserved homologs of most vertebrate microvillar genes, most of which are expressed in choanocytes, and many of which exhibit choanocyte-specific or choanocyte-enriched expression. Possible exceptions include the cadherins that form intermicrovillar links in the enterocyte brush border and hair cell stereocilia of vertebrates and cnidarians. No obvious orthologs of these proteins were detected in sponges, but at least four candidate cadherins were identified as choanocyte-enriched and might serve this function. In contrast to the evidence for conserved microvillar structure in sponges and vertebrates, we found that choanoflagellates and ctenophores lack homologs of many fundamental microvillar genes, suggesting that microvillar structure may diverge significantly in these lineages, warranting further study. CONCLUSIONS The available evidence suggests that microvilli evolved early in the prehistory of modern animals and have been repurposed to serve myriad functions in different cellular contexts. Detailed understanding of the sequence by which different microvilli-bearing cell/tissue types diversified will require further study of microvillar composition and development in disparate cell types and lineages. Of particular interest are the microvilli of choanoflagellates, ctenophores, and sponges, which collectively bracket the earliest events in animal evolution.
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Affiliation(s)
- Jesús F. Peña
- />Department of Biological Sciences, University of Denver, F.W. Olin Hall, Room 102, 2190 E. Iliff Ave., Denver, CO 80208 USA
| | - Alexandre Alié
- />Laboratoire de Biologie du Développement de Villefranche-sur-mer, CNRS, Sorbonne Universités, UPMC Univ Paris 06, Observatoire Océanographique, 06230 Villefranche-sur-mer, France
- />Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
| | - Daniel J. Richter
- />Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200 USA
- />UMR 7144, CNRS and Sorbonne Universités Université Pierre et Marie Curie (UPMC) Paris 06, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Lingyu Wang
- />Department of Biology, University of Miami, 208 Cox Science Center, 1301 Memorial Drive, Coral Gables, FL 33124 USA
| | - Noriko Funayama
- />Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
| | - Scott A. Nichols
- />Department of Biological Sciences, University of Denver, F.W. Olin Hall, Room 102, 2190 E. Iliff Ave., Denver, CO 80208 USA
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Abstract
The vertebrate small intestine requires an enormous surface area to effectively absorb nutrients from food. Morphological adaptations required to establish this extensive surface include generation of an extremely long tube and convolution of the absorptive surface of the tube into villi and microvilli. In this Review, we discuss recent findings regarding the morphogenetic and molecular processes required for intestinal tube elongation and surface convolution, examine shared and unique aspects of these processes in different species, relate these processes to known human maladies that compromise absorptive function and highlight important questions for future research.
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Affiliation(s)
- Katherine D Walton
- Cell and Developmental Biology Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Andrew M Freddo
- Cell and Developmental Biology Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Sha Wang
- Cell and Developmental Biology Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Deborah L Gumucio
- Cell and Developmental Biology Department, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Khanal I, Elbediwy A, Diaz de la Loza MDC, Fletcher GC, Thompson BJ. Shot and Patronin polarise microtubules to direct membrane traffic and biogenesis of microvilli in epithelia. J Cell Sci 2016; 129:2651-9. [PMID: 27231092 PMCID: PMC4958304 DOI: 10.1242/jcs.189076] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/19/2016] [Indexed: 01/08/2023] Open
Abstract
In epithelial tissues, polarisation of microtubules and actin microvilli occurs along the apical-basal axis of each cell, yet how these cytoskeletal polarisation events are coordinated remains unclear. Here, we examine the hierarchy of events during cytoskeletal polarisation in Drosophila melanogaster epithelia. Core apical-basal polarity determinants polarise the spectrin cytoskeleton to recruit the microtubule-binding proteins Patronin (CAMSAP1, CAMSAP2 and CAMSAP3 in humans) and Shortstop [Shot; MACF1 and BPAG1 (also known as DST) in humans] to the apical membrane domain. Patronin and Shot then act to polarise microtubules along the apical-basal axis to enable apical transport of Rab11 endosomes by the Nuf-Dynein microtubule motor complex. Finally, Rab11 endosomes are transferred to the MyoV (also known as Didum in Drosophila) actin motor to deliver the key microvillar determinant Cadherin 99C to the apical membrane to organise the biogenesis of actin microvilli.
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Affiliation(s)
- Ichha Khanal
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Ahmed Elbediwy
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | | | | | - Barry J Thompson
- The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
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The Densely O-Glycosylated MUC2 Mucin Protects the Intestine and Provides Food for the Commensal Bacteria. J Mol Biol 2016; 428:3221-3229. [PMID: 26880333 DOI: 10.1016/j.jmb.2016.02.010] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/22/2022]
Abstract
All mucins are highly O-glycosylated by variable glycans depending on species, histoblood group and organ. This makes the intestinal main mucin MUC2 non-degradable by the host digestive system but well by both commensal and pathogenic bacteria. The MUC2 glycans are important for selection of the commensal bacteria and act as a nutritional source for the bacteria; this also helps the host to recover some of the energy spent on constantly renewing the protective mucus layer. Glycosylation is the most diverse and common posttranslational modification of cell surfaces and secreted proteins. N-Glycosylation is most well studied and predictable, whereas O-glycosylation is more diverse and less well understood. O-Glycosylation is also often called mucin-type glycosylation as it is typical for mucins that often have more than 80% of the mass as O-glycans. This review will discuss the mucin-type O-glycosylation and especially the O-glycosylation of human and mice intestinal mucin MUC2 in relation to bacteria and disease.
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