May play a role in the regulation of tight junction formation. Binds phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2). Interacts (via the PDZ 2 domain) with CTNND2 (via the extreme C-terminus). Interacts (via the PDZ 2 domain) with PKP4 (via the extreme C-terminus); this interaction directed FRMPD2 to the basolateral membranes. Interacts (via the PDZ 2 domain) with ARVCF (via the extreme C-terminus). Colocalizes with CTNNB1, CDH1 and PKP4 at the basolateral membrane. Colocalizes with TJP1 at tight junctions. Its recruitment to cell-cell contacts requires CDH1. Expressed in epithelial cells. The FERM and PDZ 2 domains are necessary for localization to the basolateral cell membrane. The FERM domain binds to phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2) and is sufficient for membrane localization.