Membrane Protein, Palmitoylated 4 (MPP4)

MPP4 encodes a member of the membrane-associated guanylate kinase (MAGUK) protein family, with an N-terminal PDZ domain, a central src homology 3 region (SH3), and a C-terminal guanylate kinase-like (GUK) domain. The protein is localized to the outer limiting membrane in the retina, and is thought to function in photoreceptor polarity and the organization of specialized intercellular junctions. Alternatively spliced transcript variants have been described, but their biological validity has not been determined.The predicted 637-amino acid MPP4 protein, which is 36% identical to MPP3 and 75% identical to its rat homolog, contains an N-terminal PDZ domain, a central SH3 motif, and a C-terminal guanylate kinase (GUK)-like domain typical of MAGUK (membrane-associated GUK) proteins.