Common junctional plaque protein. The membrane-associated plaques are architectural elements in an important strategic position to influence the arrangement and function of both the cytoskeleton and the cells within the tissue. The presence of plakoglobin in both the desmosomes and in the intermediate junctions suggests that it plays a central role in the structure and function of submembranous plaques. Acts as a substrate for VE-PTP and is required by it to stimulate VE-cadherin function in endothelial cells. Can replace beta-catenin in E-cadherin/catenin adhesion complexes which are proposed to couple cadherins to the actin cytoskeleton. Homodimer. Component of an E-cadherin/catenin adhesion complex composed of at least E-cadherin/CDH1 and gamma-catenin/JUP, and possibly alpha-catenin/CTNNA1; the complex is located to adherens junctions. The stable association of CTNNA1 is controversial as CTNNA1 was shown not to bind to F-actin when assembled in the complex. Interacts with MUC1. Interacts with CAV1. Interacts with PTPRJ. Interacts with DSG1. Interacts with DSC1 and DSC2. Interacts with PKP2 (By similarity). Cytoplasmic in a soluble and membrane-associated form. The entire ARM repeats region mediates binding to CDH1/E-cadherin. The N-terminus and first three ARM repeats are sufficient for binding to DSG1. The N-terminus and first ARM repeat are sufficient for association with CTNNA1. DSC1 association requires both ends of the ARM repeat region (By similarity). May be phosphorylated by FER. Belongs to the beta-catenin family.