Phosphodiesterase 6H, cGMP Specific (PDE6H)

PDE6H encodes the inhibitory (or gamma) subunit of the cone-specific cGMP phosphodiesterase, which is a tetramer composed of two catalytic chains (alpha and beta), and two inhibitory chains (gamma). It is specifically expressed in the retina, and is involved in the transmission and amplification of the visual signal. Mutations in this gene are associated with retinal cone dystrophy type 3A (RCD3A).Shimizu-Matsumoto et al. (1996) reported the isolation of a cDNA, which they designated PDE6H, from a human retinal library. The sequence predicted an 83-amino acid protein with near identity to the bovine blue cone cGMP phosphodiesterase gamma subunit (Hamilton and Hurley, 1990). Northern blot analysis confirmed retinal expression, and in situ hybridization showed specificity of the mRNA to the cones.