QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 20, Issue 10, 2549-2562, May 15, 2009

This Article Full Text Full Text (PDF) Supplemental Materials All Versions of this Article: E08-10-1030v1 20/10/2549    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Grimm-Günter, E.-M. S. Articles by Rivero, F. Search for Related Content PubMed PubMed Citation Articles by Grimm-Günter, E.-M. S. Articles by Rivero, F.

Plastin 1 Binds to Keratin and Is Required for Terminal Web Assembly in the Intestinal Epithelium

Eva-Maria S. Grimm-Günter^*,,, Céline Revenu^,,||, Sonia Ramos^*,¶, Ilse Hurbain, Neil Smyth^#, Evelyne Ferrary^@, Daniel Louvard, Sylvie Robine, and Francisco Rivero^*,

*Center for Biochemistry, Medical Faculty, University of Cologne, D-50931 Cologne, Germany; Centre for Biomedical Research, The Hull York Medical School and Department of Biological Sciences, University of Hull, Hull HU6 7RX, United Kingdom; Unité Mixte de Recherche 144, Centre National de la Recherche Scientifique/Institut Curie, F-75248 Paris, France; ^#School of Biological Sciences, University of Southampton, Southampton SO1 6PX, United Kingdom; and ^@Unité 867 Institut National de la Santé et de la Recherche Médicale/Université Paris Diderot-Paris 7, Faculté Xavier Bichat, F-75870 Paris, France

Submitted October 14, 2008; Revised February 17, 2009; Accepted March 12, 2009
Monitoring Editor: Thomas D. Pollard

Plastin 1 (I-plastin, fimbrin) along with villin and espin is a prominent actin-bundling protein of the intestinal brush border microvilli. We demonstrate here that plastin 1 accumulates in the terminal web and interacts with keratin 19, possibly contributing to anchoring the rootlets to the keratin network. This prompted us to investigate the importance of plastin 1 in brush border assembly. Although in vivo neither villin nor espin is required for brush border structure, plastin 1-deficient mice have conspicuous ultrastructural alterations: microvilli are shorter and constricted at their base, and, strikingly, their core actin bundles lack true rootlets. The composition of the microvilli themselves is apparently normal, whereas that of the terminal web is profoundly altered. Although the plastin 1 knockout mice do not show any overt gross phenotype and present a normal intestinal microanatomy, the alterations result in increased fragility of the epithelium. This is seen as an increased sensitivity of the brush border to biochemical manipulations, decreased transepithelial resistance, and increased sensitivity to dextran sodium sulfate-induced colitis. Plastin 1 thus emerges as an important regulator of brush border morphology and stability through a novel role in the organization of the terminal web, possibly by connecting actin filaments to the underlying intermediate filament network.

These authors contributed equally to this work.

Present addresses: ^|| European Molecular Biology Laboratory, Department of Cell Biology and Biophysics, Meyerhofstrasse 1, 69126 Heidelberg, Germany;

^¶ Instituto del Frío, Consejo Superior de Investigaciones Científicas, José Antonio Novais 10, Ciudad Universitaria, 28040 Madrid, Spain.

Address correspondence to: Francisco Rivero (francisco.rivero{at}hyms.ac.uk)

Abbreviations used: BB, brush border; DSS, dextran sodium sulfate; MV, microvilli; TW, terminal web.