Recognizes a protein of 102kDa, identified as Catenin, alpha-1. Catenins comprise a large family of Ca2+-dependent, homotypic cell-cell adhesion molecules that play important roles in development, epithelial cell polarity and tumor progression. Alpha-catenin is a key regulator of actin dynamics in cell-cell adhesion. During cell-cell adhesion, -catenin and links the cadherins to actin associated with the cytoskeleton. Alpha-catenin also regulates the beta-catenin signaling in various cells. It displays the tumor suppressor activity and is found to be down regulated in some forms of breast cancer.'