This well-conserved family of animal EF-hand-containing serine/threonine protein phosphatases functions in diverse sensory neurons. The protein comprises an IQ calmodulin-binding region, a metallo-phosphoesterase domain () of the serine/threonine-specific protein phosphatase and bis(5-nucleosyl)-tetraphosphatase type, and a C-terminal extension with three calcium-binding EF-hand motifs.The prototype protein is the product of the fruit fly rdgC gene, which is required to prevent light-induced retinal degeneration []. There are two homologous mammalian genes, PPEF1 and PPEF2. Although no essential role has been identified, PPEF2 is expressed in retinal rod photoreceptors, where it assumes several splice forms, and in the pineal gland. PPEF1 is expressed in photosensory neurons and inner ear cells in the developing mouse [].
