Massive light-driven translocation of transducin between the two major compartments of rod cells: A novel mechanism of light adaptation

Maxim Sokolov, Arkady L. Lyubarsky, Katherine J. Strissel, Andrey B. Savchenko, Viktor I. Govardovskii, Edward N Pugh Jr, Vadim Y. Arshavsky

Research output: Contribution to journalArticle

277 Scopus citations


We report a new cellular mechanism of rod photoreceptor adaptation in vivo, which is triggered by daylight levels of illumination. The mechanism involves a massive light-dependent translocation of the photoreceptor-specific G protein, transducin, between the functional compartments of rods. To characterize the mechanism, we developed a novel technique that combines serial tangential cryodissection of the rat retina with Western blot analysis of protein distribution in the sections. Up to 90% of transducin translocates from rod outer segments to other cellular compartments on the time scale of tens of minutes. The reduction in the transducin content of the rod outer segments is accompanied by a corresponding reduction in the amplification of the rod photoresponse, allowing rods to operate in illumination up to 10-fold higher than would otherwise be possible.

Original languageEnglish (US)
Pages (from-to)95-106
Number of pages12
Issue number1
StatePublished - Mar 28 2002
Externally publishedYes


ASJC Scopus subject areas

  • Neuroscience(all)

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