This gene encodes the gamma subunit of cyclic GMP-phosphodiesterase, which is composed of alpha- and beta- catalytic subunits and two identical, inhibitory gamma subunits. This gene is expressed in rod photoreceptors and functions in the phototransduction signaling cascade. It is also expressed in a variety of other tissues, and has been shown to regulate the c-Src protein kinase and G-protein-coupled receptor kinase 2. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2009].