Multiple phosphorylation sites confer reproducibility of the rod's single-photon responses

Science. 2006 Jul 28;313(5786):530-3. doi: 10.1126/science.1126612.


Although signals controlled by single molecules are expected to be inherently variable, rod photoreceptors generate reproducible responses to single absorbed photons. We show that this unexpected reproducibility-the consistency of amplitude and duration of rhodopsin activity-varies in a graded and systematic manner with the number but not the identity of phosphorylation sites on rhodopsin's C terminus. These results indicate that each phosphorylation site provides an independent step in rhodopsin deactivation and that collectively these steps tightly control rhodopsin's active lifetime. Other G protein cascades may exploit a similar mechanism to encode accurately the timing and number of receptor activation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arrestin / metabolism
  • Electrophysiology
  • Mice
  • Mice, Transgenic
  • Models, Biological
  • Mutation
  • Patch-Clamp Techniques
  • Phosphorylation
  • Photons*
  • Retinal Rod Photoreceptor Cells / metabolism*
  • Rhodopsin / genetics
  • Rhodopsin / metabolism*
  • Vision, Ocular


  • Arrestin
  • Rhodopsin