The regulatory subunit of PDE6 interacts with PACSIN in photoreceptors.

Purpose: In photoreceptors, phosphodiesterase 6 (PDE6) is regulated in response to light, due to the shuttling of a regulatory subunit (PDE6gamma) between the catalytic subunits of PDE6 and the activated form of transducin. We showed previously that PDE6gamma is able to interact with the Src-homology type 3 (SH3) domain of formin-binding protein 17 (FBP17), a protein involved in membrane receptor endocytosis. FBP17 was not detected in rat retina.

A proline-rich domain in the gamma subunit of phosphodiesterase 6 mediates interaction with SH3-containing proteins.

Purpose: Phosphodiesterase 6 (PDE6) is the primary effector of phototransduction in vertebrate photoreceptors. Previous studies described the expression of the regulatory subunit of rod PDE6 (Pgamma-rod) in non-photosensitive tissues of the adult rat and the effects of this protein on MAP kinase pathways. Upon examination of the Pgamma-rod sequence, we detected a proline-rich domain that might reveal its ability to interact with SH3-containing proteins.