Photoreceptor Biochemistry

Gabriel Travis, MD, Director

Contact Information
Phone: (310) 267-2673
Fax: (310) 794-2144
Email: [email protected]

Location Address
UCLA Stein Eye Institute
100 Stein Plaza, Room BH-667
Los Angeles, CA 90095

Research Areas

Biochemistry of Vertebrate Photoreceptors and Mechanisms of Retinal Degeneration

Description

Dr. Travis is using biochemical and mouse-genetic approaches to study three aspects of photoreceptor function in vertebrate retinas. First, he is investigating the role of rds in the formation of photoreceptor outer-segments. Mutations in the RDS gene are responsible for a subset of retinitis pigmentosa. Studies to date have provided information about the function of rds and the cause of this disease. Second, he is exploring the mechanism of photoreceptor death in recessive Stargardt's macular degeneration, which results from mutations in the ABCR gene. Biochemical analysis of abcr-knockout mice suggests a pharmacologic strategy for treating patients with Stargardt's. Dr. Travis and collaborators are currently testing this promising strategy in abcr-/- mice. Finally, evidence from several sources suggests that rods and cones employ different mechanisms to regenerate visual pigments. Recent findings from Dr. Travis' laboratory point to the existence of an entirely new pathway for the recycling of visual retinoids, which appears to be specific to cones.

Research Areas

Biochemistry of Vertebrate Photoreceptors and Mechanisms of Retinal Degeneration

Description

Dr. Travis is using biochemical and mouse-genetic approaches to study three aspects of photoreceptor function in vertebrate retinas. First, he is investigating the role of rds in the formation of photoreceptor outer-segments. Mutations in the RDS gene are responsible for a subset of retinitis pigmentosa. Studies to date have provided information about the function of rds and the cause of this disease. Second, he is exploring the mechanism of photoreceptor death in recessive Stargardt's macular degeneration, which results from mutations in the ABCR gene. Biochemical analysis of abcr-knockout mice suggests a pharmacologic strategy for treating patients with Stargardt's. Dr. Travis and collaborators are currently testing this promising strategy in abcr-/- mice. Finally, evidence from several sources suggests that rods and cones employ different mechanisms to regenerate visual pigments. Recent findings from Dr. Travis' laboratory point to the existence of an entirely new pathway for the recycling of visual retinoids, which appears to be specific to cones.

Representative Publications

Radu RA, Mata NL, Bagla A, Travis GH. Light exposure stimulates formation of A2E oxiranes in a mouse model of Stargardt's macular degeneration. Proc Natl Acad Sci 2004;101:5928-33.

Jin M, Li S, Moghrabi WN, Sun H, Travis GH. Rpe65 is the retinoid isomerase in bovine retinal pigment epithelium. Cell 2005;122:449-59.

Mata NL, Ruiz A, Radu RA, Bui TV, Travis GH. Chicken retinas contain a retinoid isomerase activity that catalyzes the direct conversion of all-trans-retinol to 11-cis-retinol. Biochem 2005;44:11715-21.

Radu RA, Han Y, Bui TV, Nusinowitz S, Bok D, Lichter J, Widder K, Travis GH, Mata NL. Reductions in serum vitamin A arrest accumulation of toxic retinal fluorophores: A potential therapy for treatment of lipofuscin-based retinal diseases. Invest Ophthalmol Vis Sci 2005;46:4393-401.

Kaschula CH, Jin M, Desmond-Smith NS, Travis GH. Acyl CoA:retinol acyltransferase (ARAT) activity is present in bovine retinal pigment epithelium. Exp Eye Res 2006;82:111-21.

Grants

National Eye Institute: Regeneration of Cone Pigments & Treatment of Stargardt's, 3/02-2/07

National Eye Institute: Genetic Analysis of the Visual Cycle, 8/05-2/07

The Foundation Fighting Blindness Grant, UCLA Stein Eye Institute Research Center: Module II, Mechanisms if Lipofuscin Accumulation and Pharmacologic Intervention in a Mouse Model of Stargardt Macular Degeneration (with other Investigators), 7/05-6/10
 

Investigator/s

Joanna Kaylor, PhD