Light-dependent compartmentalization of transducin in rod photoreceptors.

Three major visual signaling proteins, transducin, arrestin, and recoverin undergo bidirectional translocations between the outer segment and inner compartments of rod photoreceptors in a light-dependent manner. The light-dependent translocation of proteins is believed to contribute to adaptation and neuroprotection of photoreceptor cells. The potential physiological significance and mechanisms of light-controlled protein translocations are at the center of current discussion. In this paper, I outline the latest advances in understanding the mechanisms of bidirectional translocation of transducin and determinants of its steady-state distribution in dark- and light-adapted photoreceptor cells.