Transducin

Function

Transducin (TDN) is a heterotrimeric G protein containing 3 chains: α, β and γ which are organized in two subunits: α and βγ. TDN is involved in phototransduction. The absorption of a photon by retinal causes a change in the conformation of rhodopsin into metarhodopsin II. The latter causes activation of TDN. Upon TDN activation the GDP bound to its α subunit is exchanged for the GTP from the cytoplasm. Deactivation of TDN occurs when the GTP bound to the α subunit is hydrolyzed to GDP. Phosducin binds to the βγ subunit of TND preventing its reassociation with the α subunit.

Disease

Relevance

Structural highlights