Enhanced Mutant Compensates for Defects in Rhodopsin Phosphorylation in the Presence of Endogenous Arrestin-1
We determined the effects of different expression levels of arrestin-1-3A mutant with enhanced binding to light-activated rhodopsin that is independent of phosphorylation. To this end, transgenic mice that express mutant rhodopsin with zero, one, or two phosphorylation sites, instead of six in the W...
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Frontiers Media S.A.
2018-06-01
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| Series: | Frontiers in Molecular Neuroscience |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fnmol.2018.00203/full |
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| author | Srimal Samaranayake Xiufeng Song Sergey A. Vishnivetskiy Jeannie Chen Eugenia V. Gurevich Vsevolod V. Gurevich |
| author_facet | Srimal Samaranayake Xiufeng Song Sergey A. Vishnivetskiy Jeannie Chen Eugenia V. Gurevich Vsevolod V. Gurevich |
| author_sort | Srimal Samaranayake |
| collection | DOAJ |
| description | We determined the effects of different expression levels of arrestin-1-3A mutant with enhanced binding to light-activated rhodopsin that is independent of phosphorylation. To this end, transgenic mice that express mutant rhodopsin with zero, one, or two phosphorylation sites, instead of six in the WT mouse rhodopsin, and normal complement of WT arrestin-1, were bred with mice expressing enhanced phosphorylation-independent arrestin-1-3A mutant. The resulting lines were characterized by retinal histology (thickness of the outer nuclear layer, reflecting the number of rod photoreceptors, and the length of the outer segments, which reflects rod health), as well as single- and double-flash ERG to determine the functionality of rods and the rate of photoresponse recovery. The effect of co-expression of enhanced arrestin-1-3A mutant with WT arrestin-1 in these lines depended on its level: higher (240% of WT) expression reduced the thickness of ONL and the length of OS, whereas lower (50% of WT) expression was harmless in the retinas expressing rhodopsin with zero or one phosphorylation site, and improved photoreceptor morphology in animals expressing rhodopsin with two phosphorylation sites. Neither expression level increased the amplitude of the a- and b-wave of the photoresponse in any of the lines. However, high expression of enhanced arrestin-1-3A mutant facilitated photoresponse recovery 2-3-fold, whereas lower level was ineffective. Thus, in the presence of normal complement of WT arrestin-1 only supra-physiological expression of enhanced mutant is sufficient to compensate for the defects of rhodopsin phosphorylation. |
| first_indexed | 2024-12-10T14:44:41Z |
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| id | doaj.art-836f3cb066a44190a2a22baa5dfb1828 |
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| issn | 1662-5099 |
| language | English |
| last_indexed | 2024-12-10T14:44:41Z |
| publishDate | 2018-06-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Molecular Neuroscience |
| spelling | doaj.art-836f3cb066a44190a2a22baa5dfb18282022-12-22T01:44:35ZengFrontiers Media S.A.Frontiers in Molecular Neuroscience1662-50992018-06-011110.3389/fnmol.2018.00203383412Enhanced Mutant Compensates for Defects in Rhodopsin Phosphorylation in the Presence of Endogenous Arrestin-1Srimal Samaranayake0Xiufeng Song1Sergey A. Vishnivetskiy2Jeannie Chen3Eugenia V. Gurevich4Vsevolod V. Gurevich5Department of Pharmacology, Vanderbilt University, Nashville, TN, United StatesDepartment of Pharmacology, Vanderbilt University, Nashville, TN, United StatesDepartment of Pharmacology, Vanderbilt University, Nashville, TN, United StatesZilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United StatesDepartment of Pharmacology, Vanderbilt University, Nashville, TN, United StatesDepartment of Pharmacology, Vanderbilt University, Nashville, TN, United StatesWe determined the effects of different expression levels of arrestin-1-3A mutant with enhanced binding to light-activated rhodopsin that is independent of phosphorylation. To this end, transgenic mice that express mutant rhodopsin with zero, one, or two phosphorylation sites, instead of six in the WT mouse rhodopsin, and normal complement of WT arrestin-1, were bred with mice expressing enhanced phosphorylation-independent arrestin-1-3A mutant. The resulting lines were characterized by retinal histology (thickness of the outer nuclear layer, reflecting the number of rod photoreceptors, and the length of the outer segments, which reflects rod health), as well as single- and double-flash ERG to determine the functionality of rods and the rate of photoresponse recovery. The effect of co-expression of enhanced arrestin-1-3A mutant with WT arrestin-1 in these lines depended on its level: higher (240% of WT) expression reduced the thickness of ONL and the length of OS, whereas lower (50% of WT) expression was harmless in the retinas expressing rhodopsin with zero or one phosphorylation site, and improved photoreceptor morphology in animals expressing rhodopsin with two phosphorylation sites. Neither expression level increased the amplitude of the a- and b-wave of the photoresponse in any of the lines. However, high expression of enhanced arrestin-1-3A mutant facilitated photoresponse recovery 2-3-fold, whereas lower level was ineffective. Thus, in the presence of normal complement of WT arrestin-1 only supra-physiological expression of enhanced mutant is sufficient to compensate for the defects of rhodopsin phosphorylation.https://www.frontiersin.org/article/10.3389/fnmol.2018.00203/fullrodphotoreceptorarrestin-1rhodopsinphosphorylationcompensation |
| spellingShingle | Srimal Samaranayake Xiufeng Song Sergey A. Vishnivetskiy Jeannie Chen Eugenia V. Gurevich Vsevolod V. Gurevich Enhanced Mutant Compensates for Defects in Rhodopsin Phosphorylation in the Presence of Endogenous Arrestin-1 Frontiers in Molecular Neuroscience rod photoreceptor arrestin-1 rhodopsin phosphorylation compensation |
| title | Enhanced Mutant Compensates for Defects in Rhodopsin Phosphorylation in the Presence of Endogenous Arrestin-1 |
| title_full | Enhanced Mutant Compensates for Defects in Rhodopsin Phosphorylation in the Presence of Endogenous Arrestin-1 |
| title_fullStr | Enhanced Mutant Compensates for Defects in Rhodopsin Phosphorylation in the Presence of Endogenous Arrestin-1 |
| title_full_unstemmed | Enhanced Mutant Compensates for Defects in Rhodopsin Phosphorylation in the Presence of Endogenous Arrestin-1 |
| title_short | Enhanced Mutant Compensates for Defects in Rhodopsin Phosphorylation in the Presence of Endogenous Arrestin-1 |
| title_sort | enhanced mutant compensates for defects in rhodopsin phosphorylation in the presence of endogenous arrestin 1 |
| topic | rod photoreceptor arrestin-1 rhodopsin phosphorylation compensation |
| url | https://www.frontiersin.org/article/10.3389/fnmol.2018.00203/full |
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