αE-catenin actin-binding domain alters actin filament conformation and regulates binding of nucleation and disassembly factors.
The actin-binding protein αE-catenin may contribute to transitions between cell migration and cell-cell adhesion that depend on remodeling the actin cytoskeleton, but the underlying mechanisms are unknown. We show that the αE-catenin actin-binding domain (ABD) binds cooperatively to individual actin filaments and that binding is accompanied by a conformational change in the actin protomer that affects filament structure. αE-catenin ABD binding limits barbed-end growth, especially in actin filament bundles. αE-catenin ABD inhibits actin filament branching by the Arp2/3 complex and severing by cofilin, both of which contact regions of the actin protomer that are structurally altered by αE-catenin ABD binding. In epithelial cells, there is little correlation between the distribution of αE-catenin and the Arp2/3 complex at developing cell-cell contacts. Our results indicate that αE-catenin binding to filamentous actin favors assembly of unbranched filament bundles that are protected from severing over more dynamic, branched filament arrays.
Department of Cellular and Molecular Pharmacology, University of California, San Francisco, School of Medicine, San Francisco, CA 94158 Department of Biology, Stanford University, Stanford, CA 94305 Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 Bioinformatics and Systems Biology Program, Sanford Burnham Medical Research Institute, La Jolla, CA 92037 Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305 Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305.
Scott D
SD
Hansen
Adam V
AV
Kwiatkowski
Chung-Yueh
CY
Ouyang
Hongjun
H
Liu
Sabine
S
Pokutta
Simon C
SC
Watkins
Niels
N
Volkmann
Dorit
D
Hanein
William I
WI
Weis
R Dyche
RD
Mullins
W James
WJ
Nelson
D008841:Actin Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D051339:Actin Depolymerizing Factors / Q000378:metabolism; D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000818:Animals; D020285:Cryoelectron Microscopy; D004285:Dogs; D007091:Image Processing, Computer-Assisted; D061985:Madin Darby Canine Kidney Cells; D051379:Mice; D008958:Models, Molecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D051178:alpha Catenin / Q000737:chemistry* / Q000378:metabolism*
D051339:Actin Depolymerizing Factors; D051376:Actin-Related Protein 2-3 Complex; D000199:Actins; D051178:alpha Catenin