Spontaneous activity of opsin apoprotein is a cause of Leber congenital amaurosis

Nat Genet. 2003 Oct;35(2):158-64. doi: 10.1038/ng1246. Epub 2003 Sep 21.


Mutations in Rpe65 disrupt synthesis of the opsin chromophore ligand 11-cis-retinal and cause Leber congenital amaurosis (LCA), a severe, early-onset retinal dystrophy. To test whether light-independent signaling by unliganded opsin causes the degeneration, we used Rpe65-null mice, a model of LCA. Dark-adapted Rpe65-/- mice behaved as if light adapted, exhibiting reduced circulating current, accelerated response turn-off, and diminished intracellular calcium. A genetic block of transducin signaling completely rescued degeneration irrespective of an elevated level of retinyl ester. These studies clearly show that activation of sensory transduction by unliganded opsin, and not the accumulation of retinyl esters, causes light-independent retinal degeneration in LCA. A similar mechanism may also be responsible for degeneration induced by vitamin A deprivation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Apoproteins / genetics
  • Apoproteins / metabolism
  • Calcium / physiology
  • Carrier Proteins
  • Darkness
  • Eye Proteins / genetics
  • Eye Proteins / physiology
  • Ion Channel Gating / physiology
  • Ion Channels / physiology
  • Mice
  • Mice, Knockout
  • Models, Biological
  • Optic Atrophy, Hereditary, Leber / genetics*
  • Proteins / genetics*
  • Proteins / physiology
  • RNA, Messenger / genetics
  • Rod Opsins / genetics
  • Rod Opsins / metabolism*
  • Transcription, Genetic
  • cis-trans-Isomerases


  • Apoproteins
  • Carrier Proteins
  • Eye Proteins
  • Ion Channels
  • Proteins
  • RNA, Messenger
  • Rod Opsins
  • retinoid isomerohydrolase
  • cis-trans-Isomerases
  • Calcium