A mathematical model of alpha-catenin dimerization at adherens junctions in polarized epithelial cells.
The protein alpha-catenin is found as a monomer or homodimer. As a monomer, alpha-catenin can bind to beta-catenin, which localizes to the plasma membrane at the site of adherens junctions (AJs) in polarized epithelial cells. As a dimer, alpha-catenin can bind to actin filaments, affecting the organization of the actin cytoskeleton. At usual cytoplasmic concentrations, alpha-catenin is found predominantly in monomeric form. It is currently thought that alpha-catenin cannot simultaneously bind beta-catenin and homodimerize, and that the dynamics of binding and unbinding from beta-catenin, possibly coupled with lower diffusion near an AJ, are sufficient to locally accumulate alpha-catenin monomers and homodimers. Using a mathematical model of alpha-catenin dynamics, I show that alpha-catenin must transiently homodimerize while bound to beta-catenin in order for homodimers to form, even in the presence of a spatial diffusion gradient.
Dawes
Adriana T
AT
Center for Cell Dynamics, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA. atdawes@math.ualberta.ca
D022005:Adherens Junctions / Q000378:metabolism*; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D004058:Diffusion; D004847:Epithelial Cells / Q000378:metabolism*; D008954:Models, Biological; D055503:Protein Multimerization / Q000502:physiology; D051178:alpha Catenin / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism
D051178:alpha Catenin; D051176:beta Catenin