Phototransduction motifs and variations

Cell. 2009 Oct 16;139(2):246-64. doi: 10.1016/j.cell.2009.09.029.


Seeing begins in the photoreceptors, where light is absorbed and signaled to the nervous system. Throughout the animal kingdom, photoreceptors are diverse in design and purpose. Nonetheless, phototransduction-the mechanism by which absorbed photons are converted into an electrical response-is highly conserved and based almost exclusively on a single class of photoproteins, the opsins. In this Review, we survey the G protein-coupled signaling cascades downstream from opsins in photoreceptors across vertebrate and invertebrate species, noting their similarities as well as differences.

Publication types

  • Review

MeSH terms

  • Animals
  • Humans
  • Light Signal Transduction*
  • Photoreceptor Cells, Invertebrate / metabolism
  • Photoreceptor Cells, Vertebrate
  • Receptors, G-Protein-Coupled / metabolism*


  • Receptors, G-Protein-Coupled