DOCSLIB.ORG

Molecular Heterogeneity of Adherens Junctions

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Molecular Heterogeneity of Adherens Junctions Published October 1, 1985 Molecular Heterogeneity of Adherens Junctions BENJAMIN GEIGER, TALILA VOLK, and TOVA VOLBERG Department of Chemical Immunology, The Weizmann Institute of Science, Rehovot 76100, Israel ABSTRACT We describe here the subcellular distributions of three junctional proteins in different adherens-type contacts. The proteins examined include vinculin, talin, and a recently described 135-kD protein (Volk, T., and B. Geiger, 1984, EMBO (Eur. Mol. Biol. Organ.) J., 10:2249-2260). Immunofluorescent localization of the three proteins indicated that while vinculin was ubiquitously present in all adherens junctions, the other two showed selective Downloaded from and mutually exclusive association with either cell-substrate or cell-cell adhesions. Talin was abundant in focal contacts and in dense plaques of smooth muscle, but was essentially absent from intercellular junctions such as intercalated disks or adherens junctions of lens fibers. The 135-kD protein, on the other hand, was present in the latter two loci and was apparently absent from membrane-bound plaques of gizzard or from focal contacts. Radioimmunoassay of tissue extracts and immunolabeling of cultured chick lens cells indicated that the selective jcb.rupress.org presence of talin and of the 135-kD protein in different cell contacts is spatially regulated within individual cells. On the basis of these findings it was concluded that adherens junctions are molecularly heterogeneous and consist of at least two major subgroups. Contacts with noncellular sub- on June 15, 2009 strates contain talin and vinculin but not the 135-kD protein, whereas their intercellular counterparts contain the latter two proteins and are devoid of talin. The significance of these results and their possible relationships to contact-induced regulation of cell behavior are discussed. Adherens junctions consist of a family of stable cell contacts Recently two relevant proteins were described which are in which actin is characteristically associated with the endo- specifically bound to adherens junctions, including talin (9, facial surfaces of the plasma membrane (16, 20, 23, 40). 34) and a 135-kD protein (45). The former is a 215-kD protein Typical examples of adherens junctions are the zonula and isolated initially from chicken smooth muscle. Immunoflu- fascia adherentes of polarized epithelia and cardiac myocytes orescent labeling of cultured chick cells with talin-specific (32, 42), small adhesions of fibroblasts (29), focal contacts in antibodies yielded patchy patterns along the ventral cell sur- cell cultures (3, 18), dense plaque of smooth muscle (19), etc. faces which were nearly identical to those of vinculin. The The major justification for the reference to all these morpho- requirement for cell permeabilization as well as the relative logically diverse structures as a closely related group of cell resistance of talin towards treatment with actin-severing pro- contacts was the apparent molecular homology between them. teins such as fragmin (22) suggested that talin, like vincuhn, Studies in several laboratories indicated that all adherens is a component of the junctional plaque. junctions contain vinculin at their cytoplasmic aspects, and it The 135-kD protein was identified with a monoclonal was thus postulated that vinculin is involved in the linkage of antibody (mAb) ~ raised against integral membrane proteins actin to the membrane in these sites. The presence of a of chick cardiac intercalated disks (45). Immunofluorescent ubiquitous "plaque" component in all adherens junctions and localization indicated that these mAb's, designated ID 7-2.3, their apparent association with actin filaments have raised the react specifically with the intercalated disks of chick cardiac possibility that, in spite of considerable morphological varia- muscle as well as with intercellular contacts of cultured my- bility, the molecular homology between all adherensjunctions ocytes or lens cells. may be quite extensive. To study this aspect directly we have In the present study, we compared the distributions oftalin, tried to identify additional components of adherens junctions and study their spatial distributions in cells and tissues. Abbreviations used in this paper: mAb, monoclonal antibody. THE JOURNAL OF CELL BIOLOGY • VOLUME 101 OCTOBER 1985 1523-1531 1523 © The Rockefeller University Press • 0021-9525/85/10/1523/09 $1.00 Published October 1, 1985 vinculin, and the 135-kD protein in various cells and tissues. droplets and indirectly immunofluorescently labeled as described earlier (17). We show here that while vinculin is ubiquitously present in Lens cell cultures were prepared from 6-8-d-old chick embryos and subcultured on 18-ram coverslips. Most of the cultured cells exhibited an epithelioid all adherens junctions, the 135-kD protein is associated only morphology and formed dense sheets. For immunofluorescent labeling, cells with intercellular contacts and talin with attachments to non- were permeabilized by a 2-rain exposure to 0.5% Triton X-100 in 50 mM cellular matrices exclusively. This molecular heterogeneity of morpholinoethane sulfonate buffer, 3 mM EGTA, 5 mM MgCI2, pH 6.0, and adherensjunctions appears to be spatially regulated since both fixed for 30 rain with 3% paraformaldehyde. Double-immunofluoreseent la- types of junctions may co-exist within the same individual beling was carried out, largely as described (18) using, in conjunction, mouse and rabbit antibodies. It was routinely verified that the secondary goat antibod- cells. ies were exclusively reactive with their respective antigens. Immunoelectron Microscopy: Chicken gizzard was dissected into MATERIALS AND METHODS square, l-mm blocks in 3% paraformaldehyde containing 0.1% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.2). After a l-h fixation, the tissue blocks were tmmunochemicat Reagents: Anti-vinculin was prepared in rabbits rinsed and incubated for at least 1 h in 0.9 M sucrose. Ultrathin frozen sections (polyclonal) or in mice (monoclonal), and affinity purified on Sepharose-bound of 600 ,g, thickness were then cut in the Sorvall ultracryomicrotome as described chicken gizzard vinculin (18). Rabbit antibodies to talin were kindly provided above. The sections were recovered on 300 mesh grids and immunolabeled by K. Burridge from the University of North Carolina at Chapel Hill. In some indirectly with talin antibodies and gold-conjugated (10 nm) goat anti-rabbit experiments we used mAb's raised by us against chicken talin. The specificity IgG (Janssen Pharmaceuticals, Beerse, Belgium). of these mAb's was determined by immunofluorescent labeling and immuno- Quantitative Immunochemical Determination of Vinculin blotting analyses (unpublished data). As secondary antibody reagents we used 135-kD Protein and Talin in Chicken Tissues: Chicken heart, goat anti-rabbit Ig or goat anti-mouse F(ab)2, both affinity purified. These lens, and gizzard were homogenized in 10, 15, and 30 volumes, respectively, of antibodies were coupled to rhodamine-lissamine sulfonyl chloride or to di- RIPA buffer (50 mM Tris-HCl, 150 mM NaCI, 0.1% SDS, 1% deoxycholate, chlorotriazinyl amino fluoreseein as previously described (4, 8). Fluorescent 1% Triton X-100, pH 7.2) and the non-extractable residue removed by a 30- labeling of actin was performed using rhodamine-phalloidine kindly supplied min centrifugation in an Eppendorff microcentrifuge. The supernatant was by Dr. H. Faulstich, from the Max-Planck Institute, Heidelberg, FRG (47). applied in threefold dilutions to V-shaped multiwell plates (Dynatech Labora- ImmunohistochemicalLabeling: Thinfrozensections(0.5-1 ~m) tories, Inc., Alexandria, VA) for 30 rain at 4"C. After extensive rinsing in PBS of chicken gizzard, heart, and lens were prepared according to Tokuyasu (41 containing 1% bovine serum albumin, monoclonal mouse antibodies (hybri- [see also reference 27]) in the Sorvall MT2B ultramicrotome with a cryoattach- doma supernatant used at various dilution between 1:20 and 1:2,000) were merit. The sections were retrieved with a platinum loop in 2.3 M sucrose added in 50 ul for 1 h to the wells. The wells were then rinsed, incubated with Downloaded from jcb.rupress.org on June 15, 2009 FIGURE 1 Immunofluorescent localization of vinculin (A), talin (B), the 135-kD protein (C), and actin (D) in thin frozen sections of chicken cardiac muscle. The arrows point to intercalated disk-containing areas, identified by phase-contrast microscopy. The arrowhead in C points to contact sites along the lateral cell membranes. Notice the extensive labeling of intercalated disks for vinculin and for the 135-kD protein and the apparent absence of labeling of these sites with talin antibodies. Bar, 10/~m. 1524 THE JOURNAL OF CELL BIOLOGY - VOLUME 101, 1985 Published October 1, 1985 ~2~l-labeled goat anti-mouse Ig (70,000 cpm/well), rinsed again, and counted in vascular smooth muscle, as shown in Fig. 1 B. Staining with a gamma counter (Kontron AG Analytical Export, Zurich, Switzerland). mAb ID 7-2.3 (anti-135-kD protein) showed a restricted labeling confined mostly to the intercalated disks (Fig. 1 C). RESULTS Comparison of the labeling pattern to the phase-contrast Localization of Microfilament-associated Proteins: image of the section was shown in reference 45. Actin, visu- Actin, Vinculin, Talin, and the 135-kD Protein in alized with rhodamine-phalloidin, exhibited a typical striated pattern corresponding to the sarcomeric periodicity in the Cardiac Muscle, Smooth Muscle, and Eye Lens myocytes
Load more

Recommended publications
  • Cadherin-Mediated Adhesion Is Essential for Myofibril Continuity Across the Plasma Membrane but Not for Assembly of the Contract
    Research Article 1471 Cadherin-mediated adhesion is essential for myofibril continuity across the plasma membrane but not for assembly of the contractile apparatus Yang Luo and Glenn L. Radice* Center for Research on Reproduction and Women’s Health, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA *Author for correspondence (e-mail: [email protected]) Accepted 23 December 2002 Journal of Cell Science 116, 1471-1479 © 2003 The Company of Biologists Ltd doi:10.1242/jcs.00339 Summary The strong coordinated contraction of heart muscle is however, alignment of the myofibrils through regions of dependent on the correct alignment and connection of the cell-cell contact was lost, resulting in their random myofibrils across the plasma membrane. Previous studies orientation. Gap junctions were perturbed in the N- indicate that N-cadherin is involved in cardiac myocyte cadherin-null myocytes. By contrast, focal contacts adhesion and myofibrillogenesis. To investigate whether N- appeared normal in the mutant cells. Furthermore, E- cadherin is specifically required for normal myocyte cadherin restored normal cell morphology and behavior structure and function, we cultured myocytes from wild- to the N-cadherin-deficient myocytes, including proper type, N-cadherin-null and mutant embryos expressing the alignment of the myofibrils. We conclude that a different epithelial cadherin E-cadherin. In contrast to previous adhesive system, most probably integrin, is responsible for studies in chicken using N-cadherin-perturbing antibodies, myofibrillogenesis in the N-cadherin-null myocytes. our in vitro studies with mouse cells demonstrate that N- cadherin is not required for myofibrillogenesis, but is critical for myofibril organization.
    [Show full text]
  • Adherens Junctions on the Move—Membrane Trafficking of E-Cadherin
    Downloaded from http://cshperspectives.cshlp.org/ on September 26, 2021 - Published by Cold Spring Harbor Laboratory Press Adherens Junctions on the Move—Membrane Trafficking of E-Cadherin Lena Bru¨ser1 and Sven Bogdan1,2 1Institut fu¨r Neurobiologie, Universita¨tMu¨nster, Badestraße 9, 48149 Mu¨nster, Germany 2Institut fu¨r Physiologie und Pathophysiologie, Abteilung Molekulare Zellphysiologie, Phillips-Universita¨t Marburg, Emil-Mannkopff-Straße 2, 35037 Marburg, Germany Correspondence: [email protected] Cadherin-based adherens junctions are conserved structuresthat mediate epithelial cell–cell adhesion in invertebrates andvertebrates. Despite their pivotal function in epithelial integrity, adherens junctions show a remarkable plasticity that is a prerequisite for tissue architecture and morphogenesis. Epithelial cadherin (E-cadherin) is continuously turned over and under- goes cycles of endocytosis, sorting and recycling back to the plasma membrane. Mammalian cell culture and genetically tractable model systems such as Drosophila have revealed con- served, but also distinct, mechanisms in the regulation of E-cadherin membrane trafficking. Here, we discuss our current knowledge about molecules and mechanisms controlling endocytosis, sorting and recycling of E-cadherin during junctional remodeling. he ability of epithelial cells to organize into Classical cadherins such as E-cadherin are Tmonolayered sheets is a prerequisite for single-pass membrane proteins with character- multicellularity, thereby providing tissue in- istic extracellular cadherin (EC) repeat do- tegrity, barrier function, and tissue polarity in mains that mediate trans-homophilic interac- metazoan organisms. Adherens junctions (AJs) tions between neighboring cells. While the are conserved key structures that mediate cell– numbers of ECs vary between different species, cell adhesion in invertebrates and vertebrates.
    [Show full text]
  • Regulated Assembly of Tight Junctions by Protein Kinase C ROBERT 0
    Proc. Natl. Acad. Sci. USA Vol. 92, pp. 6072-6076, June 1995 Cell Biology Regulated assembly of tight junctions by protein kinase C ROBERT 0. STUART AND SANJAY K. NIGAM* Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 Communicated by Carl W. Gottschalk, University of North Carolina, Chapel Hill, NC, March 14, 1995 (received for review December 7, 1994) ABSTRACT We have previously shown that protein phos- We have previously observed localized changes in intracel- phorylation plays an important role in the sorting and assembly lular calcium at sites of cell-cell contact as MDCK cells of tight junctions. We have now examined in detail the role of establish intercellular junctions and hypothesized a role for this protein kinases in intercellular junction biogenesis by using a ion in signaling relevant to intercellular-junction formation (4, combination of highly specific and broad-spectrum inhibitors 6). In addition, previous studies have suggested a role for that act by independent mechanisms. Our data indicate that phosphorylation in the assembly of tight junctions and sorting protein kinase C (PKC) is required for the proper assembly of of tight-junction proteins, zona occludens 1 (ZO-1) and cin- tight junctions. Low concentrations of the specific inhibitor of gulin, to the tight junction (3, 7). Using a combination of highly PKC, calphostin C, markedly inhibited development oftransepi- specific, as well as broad-spectrum, inhibitors of protein ki- thelial electrical resistance, a functional measure of tight- nases, we now detect apparent selective regulation of the junction biogenesis. The effect of PKC inhibitors on the devel- biogenesis oftightjunctions by protein kinase C (PKC) without opment of tight junctions, as measured by resistance, was par- immunocytochemical evidence of an effect on desmosome and alleled by a delay in the sorting ofthe tight-junction protein, zona adherens junction biogenesis.
    [Show full text]
  • University of London Thesis
    REFERENCE ONLY UNIVERSITY OF LONDON THESIS Degree fV \D Year "L ooS Name of Author C\A.OO^i COPYRIGHT This is a thesis accepted for a Higher Degree of the University of London. It is an unpublished typescript and the copyright is held by the author. All persons consulting the thesis must read and abide by the Copyright Declaration below. COPYRIGHT DECLARATION I recognise that the copyright of the above-described thesis rests with the author and that no quotation from it or information derived from it may be published without the prior written consent of the author. LOAN Theses may not be lent to individuals, but the University Library may lend a copy to approved libraries within the United Kingdom, for consultation solely on the premises of those libraries. Application should be made to: The Theses Section, University of London Library, Senate House, Malet Street, London WC1E 7HU. REPRODUCTION University of London theses may not be reproduced without explicit written permission from the University of London Library. Enquiries should be addressed to the Theses Section of the Library. Regulations concerning reproduction vary according to the date of acceptance of the thesis and are listed below as guidelines. A. Before 1962. Permission granted only upon the prior written consent of the author. (The University Library will provide addresses where possible). B. 1962 - 1974. In many cases the author has agreed to permit copying upon completion of a Copyright Declaration. C. 1975 - 1988. Most theses may be copied upon completion of a Copyright Declaration. D. 1989 onwards. Most theses may be copied.
    [Show full text]
  • The Cadherins: Cell-Cell Adhesion Molecules Controlling Animal Morphogenesis
    Development 102. 639-655 (1988) Review Article 639 Printed in Great Britain © The Company of Biologists Limited 1988 The cadherins: cell-cell adhesion molecules controlling animal morphogenesis MASATOSHI TAKEICHI Department of Biophysics, Faculty of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606, Japan Summary Cadherins are a family of glycoproteins involved in the compact type, providing direct evidence for a key role Ca2+-dependent cell-cell adhesion mechanism which of cadherins in cell-cell adhesion. It has been sugges- is detected in most kinds of tissues. Inhibition of the ted that cadherins bind cells by their homophilic cadherin activity with antibodies induces dissociation interactions at the extracellular domain and are as- of cell layers, indicating a fundamental importance of sociated with actin bundles at the cytoplasmic domain. these molecules in maintaining the multicellular struc- It appears that each cadherin subclass has binding ture. Cadherins are divided into subclasses, including specificity and this molecular family is involved in E-, N- and P-cadherins. While all subclasses are selective cell-cell adhesion. In development, the ex- similar in molecular weight, Ca2+- and protease- pression of each cadherin subclass is spatiotemporally sensitivity, each subclass is characterized by a unique regulated and associated with a variety of morphogen- tissue distribution pattern and immunological speci- etic events; e.g. the termination or initiation of ex- ficity. Analysis of amino acid sequences deduced from pression of a cadherin subclass in a given cell collective cDNA encoding these molecules showed that they are is correlated with its segregation from or connection integral membrane proteins of 723-748 amino acids with other cell collectives.
    [Show full text]
  • Cell Culture Models of Oral Mucosal Barriers: a Review with a Focus on Applications, Culture Conditions and Barrier Properties
    TISSUE BARRIERS 2018, VOL. 6, NO. 3, e1479568 (42 pages) https://doi.org/10.1080/21688370.2018.1479568 Cell culture models of oral mucosal barriers: A review with a focus on applications, culture conditions and barrier properties Lisa Bierbaumera*, Uwe Yacine Schwarze b,c, Reinhard Gruber b,c,d, and Winfried Neuhaus a aCompetence Unit Molecular Diagnostics, Center Health and Bioresources, Austrian Institute of Technology (AIT) GmbH, Vienna, Austria; bDepartment of Oral Biology, School of Dentistry, Medical University of Vienna, Vienna, Austria; cAustrian Cluster for Tissue Regeneration, Vienna, Austria; dDepartment of Periodontology, School of Dental Medicine, University of Bern, Bern, Switzerland ABSTRACT ARTICLE HISTORY Understanding the function of oral mucosal epithelial barriers is essential for a plethora of Received 15 May 2018 research fields such as tumor biology, inflammation and infection diseases, microbiomics, phar- Accepted 17 May 2018 macology, drug delivery, dental and biomarker research. The barrier properties are comprised by a KEYWORDS physical, a transport and a metabolic barrier, and all these barrier components play pivotal roles in saliva; tight junctions; the communication between saliva and blood. The sum of all epithelia of the oral cavity and desmosomes; ABC- salivary glands is defined as the blood-saliva barrier. The functionality of the barrier is regulated by transporters; SLC- its microenvironment and often altered during diseases. A huge array of cell culture models have transporter; been developed to mimic specific parts of the blood-saliva barrier, but no ultimate standard in craniomaxillofacial surgery; vitro models have been established. This review provides a comprehensive overview about salivary gland; tongue; developed in vitro models of oral mucosal barriers, their applications, various cultivation protocols gingivitis; periodontitis and corresponding barrier properties.
    [Show full text]
  • Chapter 7 Cell Adhesion and the Extracellular Matrix
    Chapter 7 Cell Adhesion and the Extracellular Matrix © 2020 Elsevier Inc. All rights reserved. Figure 7–1. Types of cell adhesion molecules. © 2020 Elsevier Inc. All rights reserved. 2 Figure 7–2. Structural features of selectins and PSGL-1. (Adapted from Kappelmayer, Nagy. Biomed Res Int 2017, https://doi.org/10.1155/2017/6138145, by permission with added colors.) © 2020 Elsevier Inc. All rights reserved. 3 Figure 7–3. Integrin activation and clustering. (A) Domain structure of integrin subunits, (B) activation and clustering of integrins. © 2020 Elsevier Inc. All rights reserved. 4 Figure 7–4. Hierarchical organization of integrin clusters in migrating cell. Image of a mouse embryonic fibroblast spread on fibronectin-coated substrate for 30 min. dSTORM imaging of endogenous paxillin conjugated (labeled with paxillin antibody, BD biosciences) to antibody tagged with AlexaFlour-647 (antimouse secondary antibody conjugated to AlexaFlour-647). Gray scale shows the TIRF image, whereas false color image shows the reconstructed superresolution image. Color code (top left corner, from left to right) indicates increasing intensity of molecules. Encircled in dotted lines from left- to right-cell edge, nascent adhesions, maturing adhesions, mature adhesions. Scale bar 2 μm. (Adapted from Changede, Sheetz. BioEssays 2016;39:1, 1600123, by permission.) © 2020 Elsevier Inc. All rights reserved. 5 Figure 7–5. Intercellular junctions and the junctional complex. Simple epithelial cells have a junctional complex at their apicolateral borders. The components are the tight junction, the adherens junction, and the desmosome. The tight and adherens junctions are zonular, extending right around the cells, whereas desmosomes are punctate. Desmosomes are also present beneath the junctional complex, as is another punctate junction, the gap junction.
    [Show full text]
  • The Adherens Junction Interactome and the Role of Vinculin in Cytoskeletal Integration at the Cardiomyocyte ICD
    Title P age The Adherens Junction Interactome and the Role of Vinculin in Cytoskeletal Integration at the Cardiomyocyte ICD by Chelsea DeAnn Merkel B.S., Eastern University, 2013 Submitted to the Graduate Faculty of the School of Medicine in partial fulfillment of the requirements for the degree of Doctor of Philosophy University of Pittsburgh 2019 Committee M emb er ship P ag e UNIVERSITY OF PITTSBURGH SCHOOL OF MEDICINE This dissertation was presented by Chelsea DeAnn Merkel It was defended on June 21, 2019 and approved by Ora A. Weisz, Professor, Dept. of Medicine, Renal-Electrolyte Division; Department of Cell Biology Bernhard Kühn, Associate Professor, Department of Pediatrics Simon C. Watkins, Distinguished Professor, Department of Cell Biology Gerald R. Hammond, Assistant Professor, Department of Cell Biology Dissertation Director: Adam V. Kwiatkowski, Assistant Professor, Department of Cell Biology ii Copyright © by Chelsea DeAnn Merkel 2019 iii Ab stract The Adherens Junction Interactome and the Role of Vinculin in Cytoskeletal Integration at the Cardiomyocyte ICD Chelsea DeAnn Merkel, PhD University of Pittsburgh, 2019 The primary function of the heart is to contract and pump oxygenated blood throughout the body. Coordinated contraction between individual cardiomyocytes requires mechanical and electrical coupling through a specialized adhesive structure called the intercalated disc (ICD). The ICD joins cardiomyocytes and is comprised of adherens junctions (AJ), desmosomes, and gap junctions. The core of the AJ is the cadherin-catenin complex and it links the myofibrils of neighboring cells. Much work has been performed in epithelial cells to study the role of force in regulating complex formation and ligand recruitment.
    [Show full text]
  • Cell Junctions : Structure & Role
    Cell Junctions : structure & role Dr. R. Debnath Assoc. Professor Deptt. of Zoology M.B.B. College 22-02-2019 Contents 1. Plasma membrane its structure & components 2. Extracellular matrix & its role 3. Types of cell junctions 4. Tight junctions, molecular structure & role - Blood brain barrier 5. Adherens junctions structure & role 6. Desmosomes structure & role 7. Hemidesmosomes 8. Focal adhesions 9. Gap junctions structure & function Conclusion References Plasma Membrane Definition: The Plasma membrane is a thin bi- layered structure which surrounds each cell, consists of lipids (phospholipids 75%, cholesterol 20%,glycolipids 5%), proteins (partially or completely embedded), carbohydrates etc., It is usually 6-10 nm thick. It is always asymmetrical. Plasma membrane structure Plasma Membrane: composition Proteins of Plasma Membrane cholesterol oligosaccharide groups phospholipids EXTRACELLULAR ENVIRONMENT (cytoskeletal proteins beneath the open gated gated active RECEPTOR LIPID plasma membrane) ADHESION channel channel channel transport PROTEIN BILAYER PROTEIN protein proten proten protein (open) (closed) RECOGNITION (area of PROTEIN enlargment) TRANSPORT PROTEINS CYTOPLASM PLASMA MEMBRANE Extracellular matrix (ECM) Many animal cells are intrinsically linked to other cells and to the extracellular matrix (ECM). The ECM fills the spaces between cells and tissues together. Bone and cartilage are mostly ECM plus a very few cells. ECM is most abundant in Connective tissue, that surrounds glands and blood vessels, is a gelatinous
    [Show full text]
  • Signaling in Adherens and Gap Junction Assembly in Corneal Epithelium
    Rho and Rho-Kinase (ROCK) Signaling in Adherens and Gap Junction Assembly in Corneal Epithelium Susan C. Anderson, Cynthia Stone, Lisa Tkach, and Nirmala SundarRaj PURPOSE. To examine whether Rho and its downstream target, tion of the transmembrane connexon from one cell with the a Rho-associated kinase (ROCK), are involved in the regulation connexon of the adjoining cell. The turnover time of Cx has of the assembly of cadherin-mediated cell adhesion and con- been reported to be very short, with a half-life of only 1.3–2 nexin 43 (Cx43) gap junctions in corneal epithelium. hours.6–8 The mechanisms of the transport of connexins to the METHODS. Rho and ROCK activities in rabbit corneal epithelial cell membranes from the Golgi and the alignment of opposing cells in culture were inhibited by microinjection of a Clostrid- connexons to form the gap junction channels are poorly un- ium botulinum ADP-ribosyltransferase (C3) and treatment derstood, and the possible interacting molecules involved in with a ROCK specific inhibitor (Y-27632), respectively. Immu- the assembly of gap junctions have not yet been identified. nocytochemical and Western blot techniques were used to Several reported findings suggest that the formation of cad- study the distribution and relative concentrations of E-cadherin herin-based adherens junctions precedes and facilitates the and Cx43. Intercellular communication via gap junctions was assembly of connexons at the cell–cell contact regions.9–14 For measured by a dye transfer assay. example, the inhibition of E-cadherin– or N-cadherin–based cell–cell adhesion, using antibodies to these proteins, has been RESULTS.
    [Show full text]
  • E-Cadherin Mediates Adherens Junction Organization Through Protein Kinase C
    SUNY Geneseo KnightScholar Biology Faculty/Staff Works Department of Biology 1994 E-cadherin mediates adherens junction organization through protein kinase C Jani E. Lewis SUNY Geneseo Pamela J. Jensen Keith R. Johnson Margaret J. Wheelock Follow this and additional works at: https://knightscholar.geneseo.edu/biology Recommended Citation Lewis J.E., Jensen P.J., Johnson K.R., Wheelock M.J. (1994) E-cadherin mediates adherens junction organization through protein kinase C. Journal of Cell Science 107: 3615-3621. doi: This Article is brought to you for free and open access by the Department of Biology at KnightScholar. It has been accepted for inclusion in Biology Faculty/Staff Works by an authorized administrator of KnightScholar. For more information, please contact [email protected]. Journal of Cell Science 108, 3615-3621 (1995) 3615 Printed in Great Britain © The Company of Biologists Limited 1995 E-cadherin mediates adherens junction organization through protein kinase C Jani E. Lewis1, Pamela J. Jensen2,*, Keith R. Johnson1 and Margaret J. Wheelock1,*,† 1Department of Biology, University of Toledo, Toledo, OH 43606, USA 2Department of Dermatology, University of Pennsylvania, Philadelphia, PA 19104, USA *Drs Jensen and Wheelock contributed equally to this research †Author for correspondence SUMMARY Cultured human keratinocytes maintained in 30 µM Ca2+ mediate this coordinate organization. In this report we do not form adherens junctions; however, when the extra- show that E-cadherin organizes the various junctional cellular Ca2+ concentration is raised to 1 mM, adherens components by signalling through protein kinase C. junctions form very rapidly. The formation of a junction involves the coordinate organization of intracellular and extracellular components.
    [Show full text]
  • PICK-1: a Scaffold Protein That Interacts with Nectins and Jams at Cell Junctions
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector FEBS 29430 FEBS Letters 579 (2005) 2243–2249 PICK-1: A scaffold protein that interacts with Nectins and JAMs at cell junctions Nicolas Reymond, Sarah Garrido-Urbani, Jean-Paul Borg, Patrice Dubreuil, Marc Lopez* INSERM UMR.599, Institut de Cance´rologie de Marseille, IFR 137, 27 Bvd. Leı¨-roure, 13009 Marseille, France Received 25 February 2005; revised 28 February 2005; accepted 2 March 2005 Available online 17 March 2005 Edited by Beat Imhof acterised by specific combinations of Nectin ectodomains: Abstract Nectin adhesion molecules are involved in the early steps of cell junction formation. Later during the polarisation Nectin-3 trans-interacts with poliovirus receptor (PVR), Nec- process, Nectins are components of epithelial adherens junctions tin-2 and Nectin-1, the latter is in turn able to trans-interact where they are indirectly associated with the E-cadherin/Cate- with Nectin-4 [1,9]. Some of these interactions have been de- nins complex via the adaptator AF-6. To have a better under- scribed in vivo at the pre- and post-synaptic junctions of neu- standing of Nectin-based cell junctions, we looked for some rons (Nectin-1/Nectin-3), as well as at the junctions between new NectinsÕ partners. We demonstrate that the scaffold mole- Sertoli cells and spermatids during spermiogenesis (Nectin-2/ cule PICK-1, involved in the clustering of junctional receptors Nectin-3) [1]. Moreover, Nectin-2 and PVR have been de- in synaptic junctions, interacts directly with Nectins in a PSD- scribed to interact with the NK triggering molecule, DNAM- 95/Dlg/ZO-1 domain-dependent manner and is localised at 1 (CD226), to induce the NK-mediated lysis of tumour cells adherens junctions in epithelial cells.
    [Show full text]