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Relationships among visual cycle retinoids, rhodopsin phosphorylation, and phototransduction in mouse eyes during light and dark adaptation.
- Source :
-
Biochemistry [Biochemistry] 2010 Mar 23; Vol. 49 (11), pp. 2454-63. - Publication Year :
- 2010
-
Abstract
- Phosphorylation and regeneration of rhodopsin, the prototypical G-protein-coupled receptor, each can influence light and dark adaptation. To evaluate their relative contributions, we quantified rhodopsin, retinoids, phosphorylation, and photosensitivity in mice during a 90 min illumination followed by dark adaptation. During illumination, all-trans-retinyl esters and, to a lesser extent, all-trans-retinal accumulate and reach the steady state in <1 h. Each major phosphorylation site on rhodopsin reaches a steady state level of phosphorylation at a different time during illumination. The dominant factor that limits dark adaptation is isomerization of retinal. During dark adaptation, dephosphorylation of rhodopsin occurs in two phases. The faster phase corresponds to rapid dephosphorylation of regenerated rhodopsin present at the end of the illumination period. The slower phase corresponds to dephosphorylation of rhodopsin as it forms by regeneration. We conclude that rhodopsin phosphorylation has three physiological functions: it quenches phototransduction, reduces sensitivity during light adaptation, and suppresses bleached rhodopsin activity during dark adaptation.
- Subjects :
- Animals
Esters chemistry
Esters metabolism
Eye cytology
Mice
Mice, Inbred BALB C
Ocular Physiological Phenomena radiation effects
Phosphorylation
Retinal Rod Photoreceptor Cells metabolism
Retinal Rod Photoreceptor Cells radiation effects
Time Factors
cis-trans-Isomerases metabolism
Dark Adaptation radiation effects
Darkness
Eye metabolism
Eye radiation effects
Retinoids metabolism
Rhodopsin metabolism
Vision, Ocular radiation effects
Subjects
Details
- Language :
- English
- ISSN :
- 1520-4995
- Volume :
- 49
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 20155952
- Full Text :
- https://doi.org/10.1021/bi1001085