Protein Phosphatase, EF-Hand Calcium Binding Domain 2 (PPEF2)

PPEF2 encodes a member of the serine/threonine protein phosphatase with EF-hand motif family. The protein contains a protein phosphatase catalytic domain, and at least two EF-hand calcium-binding motifs in its C terminus. Although its substrate(s) is unknown, the encoded protein, which is expressed specifically in photoreceptors and the pineal, has been suggested to play a role in the visual system. This gene shares high sequence similarity with the Drosophila retinal degeneration C (rdgC) gene. Northern blot analysis of rat tissues revealed a 3.7-kb PPEF2 mRNA in retina. In situ hybridization and cell fractionation experiments further revealed that the gene is expressed exclusively in the inner segments of the photoreceptor cells of the retina and in the pineal gland.