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Arrestin-1 expression level in rods: balancing functional performance and photoreceptor health.
- Source :
-
Neuroscience [Neuroscience] 2011 Feb 03; Vol. 174, pp. 37-49. Date of Electronic Publication: 2010 Nov 12. - Publication Year :
- 2011
-
Abstract
- In rod photoreceptors, signaling persists as long as rhodopsin remains catalytically active. Phosphorylation by rhodopsin kinase followed by arrestin-1 binding completely deactivates rhodopsin. Timely termination prevents excessive signaling and ensures rapid recovery. Mouse rods express arrestin-1 and rhodopsin at ∼0.8:1 ratio, making arrestin-1 the second most abundant protein in the rod. The biological significance of wild type arrestin-1 expression level remains unclear. Here we investigated the effects of varying arrestin-1 expression on its intracellular distribution in dark-adapted photoreceptors, rod functional performance, recovery kinetics, and morphology. We found that rod outer segments isolated from dark-adapted animals expressing arrestin-1 at wild type or higher level contain much greater fraction of arrestin-1 than previously estimated, 15-25% of the total. The fraction of arrestin-1 residing in the outer segments (OS) in animals with low expression (4-12% of wild type) is much lower, 5-7% of the total. Only 4% of wild type arrestin-1 level in the outer segments was sufficient to maintain near-normal retinal morphology, whereas rapid recovery required at least ∼12%. Supra-physiological arrestin-1 expression improved light sensitivity and facilitated photoresponse recovery, but was detrimental for photoreceptor health, particularly in the peripheral retina. Thus, physiological level of arrestin-1 expression in rods reflects the balance between short-term functional performance of photoreceptors and their long-term health.<br /> (Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.)
- Subjects :
- Animals
Arrestins genetics
Darkness
Electroretinography
Mice
Mice, Transgenic
Photoreceptor Cells, Vertebrate cytology
Retinal Rod Photoreceptor Cells cytology
Rod Cell Outer Segment metabolism
Rod Cell Outer Segment ultrastructure
Arrestins biosynthesis
Photoreceptor Cells, Vertebrate physiology
Retinal Rod Photoreceptor Cells metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1873-7544
- Volume :
- 174
- Database :
- MEDLINE
- Journal :
- Neuroscience
- Publication Type :
- Academic Journal
- Accession number :
- 21075174
- Full Text :
- https://doi.org/10.1016/j.neuroscience.2010.11.009