The long-term goal of this work is to elucidate the biophysical and biochemical mechanisms underlying visual excitation and adaptation. A deep understanding of the visual system itself is, of course, highly desirable in order to understand how it might be affected in abnormal states brought on by disease and genetic defects. In addition, the visual system is probably the most accessible of a very large family of signal transduction systems that are found in all vertebrates and invertebrates; these signal transduction systems are all based on cell surface receptors that are coupled to GTP binding proteins (G proteins). Visual pigments are examples of such G protein-coupled cell surface receptors. The findings will, therefore, have important ramifications to the understanding of odorant, hormone and neurotransmitter signaling. The approach is to use both the broad range of naturally-occurring visual systems, not only the rhodopsin/rod system, but long wavelength cone systems, mixed rod/cone systems like gecko, very short wavelength cone systems like human blue cone, and invertebrate systems such as octopus. The investigators seek to understand the similarities and differences between vision based on these distinct categories of pigments. They will focus on the events leading up to the formation of the active state of a visual pigment. They will utilize low temperature, flash-induced kinetics, FTIR (Fourier transform infrared) spectroscopies as well as light-induced photocurrents to study the transformations that a visual pigment undergoes leading up to its active state.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
7R01EY001323-28
Application #
6200794
Study Section
Visual Sciences C Study Section (VISC)
Project Start
1985-09-30
Project End
2003-09-29
Budget Start
2000-02-01
Budget End
2000-09-29
Support Year
28
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Washington
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Wang, Haiyan; Chhablani, Jay; Freeman, William R et al. (2012) Characterization of diabetic microaneurysms by simultaneous fluorescein angiography and spectral-domain optical coherence tomography. Am J Ophthalmol 153:861-867.e1
Ebrey, Thomas G; Kumauchi, Masato (2005) Does the chromophore's ring move after photoexcitation of rhodopsin? Biophys J 88:L41-2
Ashida, Akemi; Matsumoto, Kumi; Ebrey, Thomas G et al. (2004) A purified agonist-activated G-protein coupled receptor: truncated octopus Acid Metarhodopsin. Zoolog Sci 21:245-50
Takahashi, Yusuke; Ebrey, Thomas G (2003) Molecular basis of spectral tuning in the newt short wavelength sensitive visual pigment. Biochemistry 42:6025-34
Kuwata, O; Yuan, C; Misra, S et al. (2001) Kinetics and pH dependence of light-induced deprotonation of the Schiff base of rhodopsin: possible coupling to proton uptake and formation of the active form of Meta II. Biochemistry (Mosc) 66:1283-99
Ebrey, T G (2000) pKa of the protonated Schiff base of visual pigments. Methods Enzymol 315:196-207
Nakagawa, M; Iwasa, T; Kikkawa, S et al. (1999) How vertebrate and invertebrate visual pigments differ in their mechanism of photoactivation. Proc Natl Acad Sci U S A 96:6189-92
Yuan, C; Kuwata, O; Liang, J et al. (1999) Chloride binding regulates the Schiff base pK in gecko P521 cone-type visual pigment. Biochemistry 38:4649-54
Yuan, C; Chen, H; Anderson, R E et al. (1998) The unique lipid composition of gecko (Gekko Gekko) photoreceptor outer segment membranes. Comp Biochem Physiol B Biochem Mol Biol 120:785-9
Huang, L; Deng, H; Koutalos, Y et al. (1997) A resonance Raman study of the C=C stretch modes in bovine and octopus visual pigments with isotopically labeled retinal chromophores. Photochem Photobiol 66:747-54

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