The G protein-coupled receptor kinase GRK1 (rhodopsin kinase) is expressed exclusively in retinal photoreceptors and pinealocytes. In photoreceptors, this enzyme phosphorylates rhodopsin that has been activated by light, leading to the inactivation of phototransduction. Most of what is known regarding photopigment desensitization has been revealed from studies of rod photoreceptors; comparatively little is known about the process of cone pigment phosphorylation and desensitization. We have new evidence that another member of the G protein-coupled receptor kinase family, GRK3, is also expressed in retinal photoreceptors. In contrast to GRK1, GRK3 is expressed at high levels in cones but not rods. Does GRK3 modulate photopic vision through the phosphorylation and desensitization of activated cone photopigments? Does the disruption of GRK3 expression alter the photo- transduction process? The studies outlined in this proposal will address questions and shed new light on a poorly understood aspect of the phototransduction process.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32EY006935-02
Application #
6077989
Study Section
Special Emphasis Panel (ZRG1-MDCN-7 (02))
Project Start
1999-10-01
Project End
Budget Start
1999-09-30
Budget End
2000-09-29
Support Year
2
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Washington
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195