TY - JOUR
T1 - α-catenin is a molecular switch that binds E-cadherin-β-catenin and regulates actin-filament assembly
AU - Drees, Frauke
AU - Pokutta, Sabine
AU - Yamada, Soichiro
AU - Nelson, W. James
AU - Weis, William I.
PY - 2005/12/2
Y1 - 2005/12/2
N2 - Epithelial cell-cell junctions, organized by adhesion proteins and the underlying actin cytoskeleton, are considered to be stable structures maintaining the structural integrity of tissues. Contrary to the idea that α-catenin links the adhesion protein E-cadherin through β-catenin to the actin cytoskeleton, in the accompanying paper we report that α-catenin does not bind simultaneously to both E-cadherin-β-catenin and actin filaments. Here we demonstrate that α-catenin exists as a monomer or a homodimer with different binding properties. Monomeric α-catenin binds more strongly to E-cadherin-β-catenin, whereas the dimer preferentially binds actin filaments. Different molecular conformations are associated with these different binding states, indicating that α-catenin is an allosteric protein. Significantly, α-catenin directly regulates actin-filament organization by suppressing Arp2/3-mediated actin polymerization, likely by competing with the Arp2/3 complex for binding to actin filaments. These results indicate a new role for α-catenin in local regulation of actin assembly and organization at sites of cadherin-mediated cell-cell adhesion.
AB - Epithelial cell-cell junctions, organized by adhesion proteins and the underlying actin cytoskeleton, are considered to be stable structures maintaining the structural integrity of tissues. Contrary to the idea that α-catenin links the adhesion protein E-cadherin through β-catenin to the actin cytoskeleton, in the accompanying paper we report that α-catenin does not bind simultaneously to both E-cadherin-β-catenin and actin filaments. Here we demonstrate that α-catenin exists as a monomer or a homodimer with different binding properties. Monomeric α-catenin binds more strongly to E-cadherin-β-catenin, whereas the dimer preferentially binds actin filaments. Different molecular conformations are associated with these different binding states, indicating that α-catenin is an allosteric protein. Significantly, α-catenin directly regulates actin-filament organization by suppressing Arp2/3-mediated actin polymerization, likely by competing with the Arp2/3 complex for binding to actin filaments. These results indicate a new role for α-catenin in local regulation of actin assembly and organization at sites of cadherin-mediated cell-cell adhesion.
UR - http://www.scopus.com/inward/record.url?scp=28344439885&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=28344439885&partnerID=8YFLogxK
U2 - 10.1016/j.cell.2005.09.021
DO - 10.1016/j.cell.2005.09.021
M3 - Article
C2 - 16325583
AN - SCOPUS:28344439885
VL - 123
SP - 903
EP - 915
JO - Cell
JF - Cell
SN - 0092-8674
IS - 5
ER -