Human PDE6D was initially identified as a fourth subunit of rod-specific cGMP phosphodiesterase, PDE6. PDE6D is an Oligomer composed of two catalytic chains (alpha and beta), an inhibitory chain (gamma) and the delta chain. PDE6D interacts with RPGR, ARL2 and ARL3. The catalytically active PDE6 is a heterodimer (alphabeta) that is controlled by two inhibitory gamma subunits. Since PDE6D does not change the catalytic properties of PDEalphabeta, its function is still unanswered. PDE6D is expressed specifically in the retina Synonyms: Retinal rod rhodopsin-sensitive cGMP 3,5-cyclic phosphodiesterase subunit delta, Phosphodiesterase 6D cGMP-Specific Rod Delta, GMP-PDE delta, Protein p17, PDE6D, PDED