Retinal rods utilize a prototypical G-protein signaling cascade to encode our visual scene under dim light. Over-stimulation of this cascade by bright light, or genetic mutations that act as equivalent light, are known environmental factors that exacerbate disease progression for age-related macular degeneration (AMD) as well as other retinal disorders in humans. Although it is known that rhodopsin activation is required for light-induced pathogenesis, the distinct molecular pathways remain to be defined. The first two aims will investigate biochemical reactions in rods that may slow dark adaptation following bright light exposure.
The third aim will investigate two different mechanisms of light-induced rod cell death. The long-term objective of this proposal is to understand phototransduction in normal function and dysfunction so that this knowledge can be used to devise strategies for the treatment of human visual disorders.

Public Health Relevance

Photoreceptor cells utilize a prototypical G-protein signaling cascade, called phototransduction, to convey the presence of light. Genetic mutations and environmental factors that affect the performance of phototransduction cause many different forms of blinding diseases through mechanisms that are poorly understood. Investigation of these mechanisms will help in the design of treatment options for visual disorders arising from dysfunction of the phototransduction cascade.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY012155-19
Application #
9221333
Study Section
Biology of the Visual System Study Section (BVS)
Program Officer
Neuhold, Lisa
Project Start
1998-03-01
Project End
2019-01-31
Budget Start
2017-02-01
Budget End
2018-01-31
Support Year
19
Fiscal Year
2017
Total Cost
$563,252
Indirect Cost
$201,620
Name
University of Southern California
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
072933393
City
Los Angeles
State
CA
Country
United States
Zip Code
90032
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LaVail, Matthew M; Nishikawa, Shimpei; Steinberg, Roy H et al. (2018) Phenotypic characterization of P23H and S334ter rhodopsin transgenic rat models of inherited retinal degeneration. Exp Eye Res 167:56-90
Vinberg, Frans; Chen, Jeannie; Kefalov, Vladimir J (2018) Regulation of calcium homeostasis in the outer segments of rod and cone photoreceptors. Prog Retin Eye Res 67:87-101
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Vinberg, Frans; Wang, Tian; De Maria, Alicia et al. (2017) The Na+/Ca2+, K+ exchanger NCKX4 is required for efficient cone-mediated vision. Elife 6:
Wang, Tian; Tsang, Stephen H; Chen, Jeannie (2017) Two pathways of rod photoreceptor cell death induced by elevated cGMP. Hum Mol Genet 26:2299-2306
Rose, Kasey; Walston, Steven T; Chen, Jeannie (2017) Separation of photoreceptor cell compartments in mouse retina for protein analysis. Mol Neurodegener 12:28
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Sakurai, Keisuke; Vinberg, Frans; Wang, Tian et al. (2016) The Na(+)/Ca(2+), K(+) exchanger 2 modulates mammalian cone phototransduction. Sci Rep 6:32521

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