Wangsun Choi,1 Bipul R. Acharya,4,* Gregoire Peyret,5,* Marc-Antoine Fardin,5,* Rene-Marc Mege,5 Benoit Ladoux,5,6 Alpha S. Yap,4 Alan S. Fanning,2,3 and Mark Peifer1,2
1Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
2Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
3Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
4Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia 4072
5Institut Jacques Monod, Centre National de la Recherche Scientifique UMR 7592 and Universite Paris Diderot, 75013 Paris, France
6Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
Correspondence to Mark Peifer: Alan Fanning: Wangsun Choi
*B.R. Acharya, G. Peyret, and M.-A. Fardin contributed equally to this paper.
W. Choi’s present address is Dept. of Pathology and Dept. of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115.
Morphogenesis requires dynamic coordination between cell-cell adhesion and the cytoskeleton to allow cells to change shape and move without losing tissue integrity. We used genetic tools and superresolution microscopy in a simple model epithelial cell line to define how the molecular architecture of cell-cell zonula adherens (ZA) is modified in response to elevated contractility, and how these cells maintain tissue integrity. We previously found that depleting zonula occludens 1 (ZO-1) family proteins in MDCK cells induces a highly organized contractile actomyosin array at the ZA. We find that ZO knockdown elevates contractility via a Shroom3/Rho-associated, coiled-coil containing protein kinase (ROCK) pathway. Our data suggest that each bicellular border is an independent contractile unit, with actin cables anchored end-on to cadherin complexes at tricellular junctions. Cells respond to elevated contractility by increasing junctional afadin. Although ZO/afadin knockdown did not prevent contractile array assembly, it dramatically altered cell shape and barrier function in response to elevated contractility. We propose that afadin acts as a robust protein scaffold that maintains ZA architecture at tricellular junctions.