Component of the cornified envelope of keratinocytes. May link the cornified envelope to desmosomes and intermediate filaments. May act as a localization signal in PKB/AKT-mediated signaling. Homodimer or a heterodimer with EVPL (By similarity). Found in a complex composed of PPL (via C-terminal linker domain), BFSP1 and BFSP2 in the retinal lens (PubMed:19029034). Within the complex interacts (via C-terminal linker domain) with BFSP2 (PubMed:19029034). Interacts with VIM (PubMed:12244133, PubMed:19029034). Binds to the PH domain of AKT1 (PubMed:12244133). Interacts with FCGR1A (By similarity). May interact with PPHLN1 (By similarity). Expressed in the retinal lens (at protein level). Expressed in the upper granular cell layer of dorsal lip and tongue, palate and dorsal epidermis of newborns (PubMed:15226441). Expressed in the corneal epithelium and conjunctiva, with expression prevalent in the cytoplasm of anterior lens epithelial cells, becoming predominantly membrane expressed in epithelial cells as they elongate into fiber cells at 3 weeks of age (PubMed:19029034). Belongs to the plakin or cytolinker family.