The light captured by rod and cone cells of the retina triggers phototransduction. This cascade of chemical reactions is similar in both types of cells and is responsible for generating a neuronal signal. The goal of our research is to understand the biochemical mechanisms underlying the restoration of dark conditioned in photo-activated photoreceptor cells. We would like to understand how photolyzed rhodopsin is inactivated by two competing reactions, phosphorylation and reduction of photolyzed chromophore, and how the activated G protein transducin, or G/t, is recycled to its quiescent form. Another important component in the transduction cascade is the restoration of intracellular cGMP concentrations to a pre-illumination level. To understand this process more clearly, we will examine the complex regulation of retinal guanylate cyclase1, the enzyme involved in cGMP production. During the next grant period, we propose to (1) study rhodopsin phosphorylation in rod outer segments under physiological conditions to understand how this reaction is regulated. In addition, we would like to explore the importance of C-terminal modifications, isoprenylation and autophosphorylation, on the enzymatic properties of rhodopsin kinase; (2) identify the Regulator of G-protein Signaling, RGS protein, that is involved in phototransduction; (3) explore the molecular mechanism of guanylate cyclase regulation; and (4) clone and molecularly characterize retinol dehydrogenase from photoreceptor cells.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY008061-14
Application #
6342604
Study Section
Visual Sciences C Study Section (VISC)
Program Officer
Mariani, Andrew P
Project Start
1990-02-01
Project End
2003-12-31
Budget Start
2001-01-01
Budget End
2001-12-31
Support Year
14
Fiscal Year
2001
Total Cost
$903,916
Indirect Cost
Name
University of Washington
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Jastrzebska, Beata; Chen, Yuanyuan; Orban, Tivadar et al. (2015) Disruption of Rhodopsin Dimerization with Synthetic Peptides Targeting an Interaction Interface. J Biol Chem 290:25728-44
Hofmann, Lukas; Palczewski, Krzysztof (2015) The G protein-coupled receptor rhodopsin: a historical perspective. Methods Mol Biol 1271:3-18
Baker, Bo Y; Gulati, Sahil; Shi, Wuxian et al. (2015) Crystallization of proteins from crude bovine rod outer segments. Methods Enzymol 557:439-58
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Orban, Tivadar; Jastrzebska, Beata; Palczewski, Krzysztof (2014) Structural approaches to understanding retinal proteins needed for vision. Curr Opin Cell Biol 27:32-43
Chen, Yuanyuan; Tang, Hong; Seibel, William et al. (2014) Identification and characterization of novel inhibitors of Mammalian aspartyl aminopeptidase. Mol Pharmacol 86:231-42
Comar, William D; Schubert, Sarah M; Jastrzebska, Beata et al. (2014) Time-resolved fluorescence spectroscopy measures clustering and mobility of a G protein-coupled receptor opsin in live cell membranes. J Am Chem Soc 136:8342-9
Palczewski, Krzysztof (2014) Chemistry and biology of the initial steps in vision: the Friedenwald lecture. Invest Ophthalmol Vis Sci 55:6651-72
Palczewska, Grazyna; Dong, Zhiqian; Golczak, Marcin et al. (2014) Noninvasive two-photon microscopy imaging of mouse retina and retinal pigment epithelium through the pupil of the eye. Nat Med 20:785-9
Chen, Yuanyuan; Jastrzebska, Beata; Cao, Pengxiu et al. (2014) Inherent instability of the retinitis pigmentosa P23H mutant opsin. J Biol Chem 289:9288-303

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