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Sensory Rhodopsins

  1. Takashi Tsukamoto,
  2. Yuki Sudo

Published Online: 15 JAN 2014

DOI: 10.1002/9780470015902.a0022838



How to Cite

Tsukamoto, T. and Sudo, Y. 2014. Sensory Rhodopsins. eLS. .

Author Information

  1. Nagoya University, Nagoya, Japan

Publication History

  1. Published Online: 15 JAN 2014


Motile organisms sense and respond to extracellular stimuli to survive in the various environments in which they live, by changing their movement to migrate towards more favourable habitats or to avoid more harmful habitats. Light is one of the most important signals that provide critical information to biological systems and therefore many organisms utilise light not only as an energy source but also as a signal. Sensory rhodopsin is a photochemically reactive membrane-embedded protein consisting of seven transmembrane alpha-helices, which binds the chromophore retinal (vitamin A aldehyde). Sensory rhodopsin is broadly distributed through all three biological kingdoms, eukarya, bacteria and archaea, indicating the biological significance of their light signal conversion.

Key Concepts:

  • Many organisms can sense and respond to light stimuli.

  • Photoactive retinal proteins play important roles in light signal transduction in various organisms.

  • The transcis photoisomerisation of the retinal chromophore triggers the cyclic photoreaction, leading to structural changes of the protein moiety.

  • Photoactivated sensory rhodopsins regulate the activity of the cognate transducer molecules, which control the motility and morphology of the organisms.

  • Sensory rhodopsins have become a focus of interest in part because of their importance to the general understanding of light signal conversion and because of potential application for the novel technology named ‘optogenetics’, in which retinal proteins are utilised to control biological activity with high temporal and spatial resolutions.


  • light;
  • retinal;
  • signal transduction;
  • membrane protein;
  • colour;
  • isomerisation