A WAVE2–Arp2/3 actin nucleator apparatus supports junctional tension at the epithelial zonula adherens

Abstract

WAVE2–Arp2/3 is a major nucleator of actin assembly at the zonula adherens and likely acts in response to junctional Rac signaling. It supports myosin II recruitment to, and tension generation at, the junction.

Abstract

The epithelial zonula adherens (ZA) is a specialized adhesive junction where actin dynamics and myosin-driven contractility coincide. The junctional cytoskeleton is enriched in myosin II, which generates contractile force to support junctional tension. It is also enriched in dynamic actin filaments, which are replenished by ongoing actin assembly. In this study we sought to pursue the relationship between actin assembly and junctional contractility. We demonstrate that WAVE2–Arp2/3 is a major nucleator of actin assembly at the ZA and likely acts in response to junctional Rac signaling. Furthermore, WAVE2–Arp2/3 is necessary for junctional integrity and contractile tension at the ZA. Maneuvers that disrupt the function of either WAVE2 or Arp2/3 reduced junctional tension and compromised the ability of cells to buffer side-to-side forces acting on the ZA. WAVE2–Arp2/3 disruption depleted junctions of both myosin IIA and IIB, suggesting that dynamic actin assembly may support junctional tension by facilitating the local recruitment of myosin.

Contributors

Jeffrey D. Hardin: Role: Monitoring Editor

Journal

Journal ID (nlm-ta): Mol Biol Cell

Journal ID (iso-abbrev): Mol. Biol. Cell

Journal ID (hwp): molbiolcell

Journal ID (pmc): mbc

Journal ID (publisher-id): Mol. Bio. Cell

Title: Molecular Biology of the Cell

Publisher: The American Society for Cell Biology

ISSN (Print): 1059-1524

ISSN (Electronic): 1939-4586

Publication date (Print): 01 December 2012

Volume: 23

Issue: 23

Pages: 4601-4610

Affiliations

^aDivision of Molecular Cell Biology, Institute for Molecular Bioscience, St. Lucia, Brisbane 4072, Australia

^bSchool for Biomedical Sciences, University of Queensland, St. Lucia, Brisbane 4072, Australia

University of Wisconsin

Author notes

¹Address correspondence to: Alpha S. Yap ( a.yap@ 123456uq.edu.au ).

Article

Publisher ID: E12-08-0574

DOI: 10.1091/mbc.E12-08-0574

PMC ID: 3510021

PubMed ID: 23051739

Copyright statement: © 2012 Verma et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License ( http://creativecommons.org/licenses/by-nc-sa/3.0).

License:

“ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society of Cell Biology.

Product

Categories

Subject: Articles

Subject: Cytoskeleton