Cortactin scaffolds Arp2/3 and WAVE2 at the epithelial zonula adherens.
Cadherin junctions arise from the integrated action of cell adhesion, signaling, and the cytoskeleton. At the zonula adherens (ZA), a WAVE2-Arp2/3 actin nucleation apparatus is necessary for junctional tension and integrity. But how this is coordinated with cadherin adhesion is not known. We now identify cortactin as a key scaffold for actin regulation at the ZA, which localizes to the ZA through influences from both E-cadherin and N-WASP. Using cell-free protein expression and fluorescent single molecule coincidence assays, we demonstrate that cortactin binds directly to the cadherin cytoplasmic tail. However, its concentration with cadherin at the apical ZA also requires N-WASP. Cortactin is known to bind Arp2/3 directly (Weed, S. A., Karginov, A. V., Schafer, D. A., Weaver, A. M., Kinley, A. W., Cooper, J. A., and Parsons, J. T. (2000) J. Cell Biol. 151, 29-40). We further show that cortactin can directly bind WAVE2, as well as Arp2/3, and both these interactions are necessary for actin assembly at the ZA. We propose that cortactin serves as a platform that integrates regulators of junctional actin assembly at the ZA.
From the Division of Molecular Cell Biology, Institute for Molecular Bioscience, University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia.
Siew Ping
SP
Han
Yann
Y
Gambin
Guillermo A
GA
Gomez
Suzie
S
Verma
Nichole
N
Giles
Magdalene
M
Michael
Selwin K
SK
Wu
Zhong
Z
Guo
Wayne
W
Johnston
Emma
E
Sierecki
Robert G
RG
Parton
Kirill
K
Alexandrov
Alpha S
AS
Yap
D051377:Actin-Related Protein 2 / Q000378:metabolism*; D051378:Actin-Related Protein 3 / Q000378:metabolism*; D000199:Actins / Q000378:metabolism; D022005:Adherens Junctions / Q000378:metabolism*; D015703:Antigens, CD; D018938:Caco-2 Cells; D015820:Cadherins / Q000378:metabolism; D002448:Cell Adhesion; D002474:Cell-Free System; D051356:Cortactin / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D013050:Spectrometry, Fluorescence; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000378:metabolism*; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000378:metabolism
C495926:ACTR2 protein, human; C495928:ACTR3 protein, human; D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins; D015703:Antigens, CD; C513384:CDH1 protein, human; C495868:CTTN protein, human; D015820:Cadherins; D051356:Cortactin; C120152:WASF2 protein, human; C495771:WASL protein, human; D051300:Wiskott-Aldrich Syndrome Protein Family; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D049452:Green Fluorescent Proteins
Actin; Arp2/3; Cell Adhesion; Cell Junctions; Cortactin; Cytoskeleton; E-cadherin; WAVE2