May play a role in junctional plaques. Nuclear and associated with desmosomes. Isoform PKP3a is found in desmosomes of most simple and stratified epithelia. Not found in foreskin fibroblasts and various sarcoma-derived cell lines. Beside dendritic reticular cells of lymphatic follicles not found in non-epithelial desmosome-bearing tissues. Isoform PKP3b is abundant in the desmosomes of stratified epithelial cell but absent in simple epithelial cells, it is also expressed in the colon and its tumors. Belongs to the beta-catenin family.