Gabriel H Travis
Professor, Ophthalmology, University of California Los Angeles
Professor, Biological Chemistry, University of California Los Angeles
100 Stein Plaza
UCLA School of Medicine
Los Angeles, CA 90095
Stein Eye Institute
UCLA School of Medicine
Los Angeles, CA 90095
Office Phone Number:
Member, Biochemistry, Biophysics & Structural Biology GPB Home Area, Molecular, Cellular & Integrative Physiology GPB Home Area
Visual perception begins with absorption of a photon by a light-sensitive opsin in photoreceptor cells of the retina. Opsins are members of the G protein-coupled receptor (GCPR) superfamily. The visual opsins contain an 11‑cis‑retinaldehyde (11cRAL) chromophore, which is isomerized to all‑trans‑retinaldehyde (atRAL) by photon absorption. This bleaches the opsin pigment, rendering it insensitive to light. Light sensitivity is restored through the energetically uphill conversion of atRAL back to 11cRAL. Our laboratory studies the biochemical and photochemical processes that carry out this conversion. The genes for several retinoid-processing proteins are affected in human inherited retinal and macular degenerations. We are working to understand the function of several visual-cycle proteins, and how loss of function causes blindness in people with disease-causing mutations in visual-cycle genes. We are particularly interested in mechanisms that permit sustained vision under daylight conditions. Our laboratory employs a broad range of approaches to address these questions. Several exciting projects are currently available. These projects are especially suitable for students or fellows with interest in biochemistry who wish to work on problems in vision science with relevance to human inherited blindness.
Gabriel Travis is a biochemist and molecular biologist who has been on the faculty at UCLA in Ophthalmology and Biological Chemistry since 2001. Professor Travis earned his BS degree in chemistry at UCLA, and his MD at UCLA School of Medicine. After completing a residency in neurology, Professor Travis left clinical medicine and devote himself full-time to basic research. He did a postdoctoral fellowship at the UCLA with Professor Michael Grunstein, and a second postdoctoral fellowship at Scripps Research Institute with Professor J. Gregor Sutcliffe. He then took his first faculty position in Neuroscience at UT Southwestern Medical Center in Dallas, where he remained until moving to UCLA. Professor Travis currently directs a research group that studies retinoid metabolism in photoreceptor cells and the mechanisms of inherited blinding diseases.
- Frederiksen R, Morshedian A, Tripathy SA, Xu T, Travis GH, Fain GL, Sampath AP. Rod Photoreceptors Avoid Saturation in Bright Light by the Movement of the G Protein Transducin.. The Journal of neuroscience : the official journal of the Society for Neuroscience, 2021.
- Ward R, Kaylor JJ, Cobice DF, Pepe DA, McGarrigle EM, Brockerhoff SE, Hurley JB, Travis GH, Kennedy BN. Non-photopic and photopic visual cycles differentially regulate immediate, early, and late phases of cone photoreceptor-mediated vision.. The Journal of biological chemistry, 2020.
- Morshedian A, Kaylor JJ, Ng SY, Tsan A, Frederiksen R, Xu T, Yuan L, Sampath AP, Radu RA, Fain GL, Travis GH. Light-Driven Regeneration of Cone Visual Pigments through a Mechanism Involving RGR Opsin in Müller Glial Cells.. Neuron, 2019.
- Lenis TL, Hu J, Ng SY, Jiang Z, Sarfare S, Lloyd MB, Esposito NJ, Samuel W, Jaworski C, Bok D, Finnemann SC, Radeke MJ, Redmond TM, Travis GH, Radu RA. Expression of ABCA4 in the retinal pigment epithelium and its implications for Stargardt macular degeneration.. Proceedings of the National Academy of Sciences of the United States of America, 2018.
- Cook JD, Ng SY, Lloyd M, Eddington S, Sun H, Nathans J, Bok D, Radu RA, Travis GH. Peropsin modulates transit of vitamin A from retina to retinal pigment epithelium.. The Journal of biological chemistry, 2017.
- Kaylor JJ, Xu T, Ingram NT, Tsan A, Hakobyan H, Fain GL, Travis GH. Blue light regenerates functional visual pigments in mammals through a retinyl-phospholipid intermediate.. Nature communications, 2017.
- Kaylor JJ, Radu RA, Bischoff N, Makshanoff J, Hu J, Lloyd M, Eddington S, Bianconi T, Bok D, Travis GH. Diacylglycerol O-acyltransferase type-1 synthesizes retinyl esters in the retina and retinal pigment epithelium.. PloS one, 2015.
- Kaylor JJ, Cook JD, Makshanoff J, Bischoff N, Yong J, Travis GH. Identification of the 11-cis-specific retinyl-ester synthase in retinal Müller cells as multifunctional O-acyltransferase (MFAT).. Proceedings of the National Academy of Sciences of the United States of America, 2014.
- Sato K, Li S, Gordon WC, He J, Liou GI, Hill JM, Travis GH, Bazan NG, Jin M. Receptor interacting protein kinase-mediated necrosis contributes to cone and rod photoreceptor degeneration in the retina lacking interphotoreceptor retinoid-binding protein.. The Journal of neuroscience : the official journal of the Society for Neuroscience, 2013.
- Kaylor JJ, Yuan Q, Cook J, Sarfare S, Makshanoff J, Miu A, Kim A, Kim P, Habib S, Roybal CN, Xu T, Nusinowitz S, Travis GH. Identification of DES1 as a vitamin A isomerase in Müller glial cells of the retina.. Nature chemical biology, 2012.
- Mullins RF, Kuehn MH, Radu RA, Enriquez GS, East JS, Schindler EI, Travis GH, Stone EM. Autosomal recessive retinitis pigmentosa due to ABCA4 mutations: clinical, pathologic, and molecular characterization.. Investigative ophthalmology & visual science, 2012.
- Kawaguchi R, Yu J, Ter-Stepanian M, Zhong M, Cheng G, Yuan Q, Jin M, Travis GH, Ong D, Sun H. Receptor-mediated cellular uptake mechanism that couples to intracellular storage.. ACS chemical biology, 2011.
- Blakeley LR, Chen C, Chen CK, Chen J, Crouch RK, Travis GH, Koutalos Y. Rod outer segment retinol formation is independent of Abca4, arrestin, rhodopsin kinase, and rhodopsin palmitylation.. Investigative ophthalmology & visual science, 2011.
- Radu RA, Hu J, Yuan Q, Welch DL, Makshanoff J, Lloyd M, McMullen S, Travis GH, Bok D. Complement system dysregulation and inflammation in the retinal pigment epithelium of a mouse model for Stargardt macular degeneration.. The Journal of biological chemistry, 2011.
- Liao JL, Yu J, Huang K, Hu J, Diemer T, Ma Z, Dvash T, Yang XJ, Travis GH, Williams DS, Bok D, Fan G. Molecular signature of primary retinal pigment epithelium and stem-cell-derived RPE cells.. Human molecular genetics, 2010.
- Linton JD, Holzhausen LC, Babai N, Song H, Miyagishima KJ, Stearns GW, Lindsay K, Wei J, Chertov AO, Peters TA, Caffe R, Pluk H, Seeliger MW, Tanimoto N, Fong K, Bolton L, Kuok DL, Sweet IR, Bartoletti TM, Radu RA, Travis GH, Zagotta WN, Townes-Anderson E, Parker E, Van der Zee CE, Sampath AP, Sokolov M, Thoreson WB, Hurley JB. Flow of energy in the outer retina in darkness and in light.. Proceedings of the National Academy of Sciences of the United States of America, 2010.
- Travis GH, Kaylor J, Yuan Q. Analysis of the retinoid isomerase activities in the retinal pigment epithelium and retina.. Methods in molecular biology (Clifton, N.J.), 2010.
- Yuan Q, Kaylor JJ, Miu A, Bassilian S, Whitelegge JP, Travis GH. Rpe65 isomerase associates with membranes through an electrostatic interaction with acidic phospholipid headgroups.. The Journal of biological chemistry, 2009.
- Philp AR, Jin M, Li S, Schindler EI, Iannaccone A, Lam BL, Weleber RG, Fishman GA, Jacobson SG, Mullins RF, Travis GH, Stone EM. Predicting the pathogenicity of RPE65 mutations.. Human mutation, 2009.
- Jin M, Li S, Nusinowitz S, Lloyd M, Hu J, Radu RA, Bok D, Travis GH. The role of interphotoreceptor retinoid-binding protein on the translocation of visual retinoids and function of cone photoreceptors.. The Journal of neuroscience : the official journal of the Society for Neuroscience, 2009.
- Radu RA, Yuan Q, Hu J, Peng JH, Lloyd M, Nusinowitz S, Bok D, Travis GH. Accelerated accumulation of lipofuscin pigments in the RPE of a mouse model for ABCA4-mediated retinal dystrophies following Vitamin A supplementation.. Investigative ophthalmology & visual science, 2008.
- Radu RA, Hu J, Peng J, Bok D, Mata NL, Travis GH. Retinal pigment epithelium-retinal G protein receptor-opsin mediates light-dependent translocation of all-trans-retinyl esters for synthesis of visual chromophore in retinal pigment epithelial cells.. The Journal of biological chemistry, 2008.
- Brill E, Malanson KM, Radu RA, Boukharov NV, Wang Z, Chung HY, Lloyd MB, Bok D, Travis GH, Obin M, Lem J. A novel form of transducin-dependent retinal degeneration: accelerated retinal degeneration in the absence of rod transducin.. Investigative ophthalmology & visual science, 2007.
- Jin M, Yuan Q, Li S, Travis GH. Role of LRAT on the retinoid isomerase activity and membrane association of Rpe65.. The Journal of biological chemistry, 2007.
- Travis GH, Golczak M, Moise AR, Palczewski K. Diseases caused by defects in the visual cycle: retinoids as potential therapeutic agents.. Annual review of pharmacology and toxicology, 2007.
- Bui TV, Han Y, Radu RA, Travis GH, Mata NL. Characterization of native retinal fluorophores involved in biosynthesis of A2E and lipofuscin-associated retinopathies.. The Journal of biological chemistry, 2006.
- 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.. Investigative ophthalmology & visual science, 2005.
- 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.. Biochemistry, 2005.
- Jin M, Li S, Moghrabi WN, Sun H, Travis GH. Rpe65 is the retinoid isomerase in bovine retinal pigment epithelium.. Cell, 2005.
- Kaschula CH, Jin MH, Desmond-Smith NS, Travis GH. Acyl CoA:retinol acyltransferase (ARAT) activity is present in bovine retinal pigment epithelium.. Experimental eye research, 2005.
- Travis GH. DISCO! Dissociation of cone opsins: the fast and noisy life of cones explained.. Neuron, 2005.
- Radu RA, Mata NL, Bagla A, Travis GH. Light exposure stimulates formation of A2E oxiranes in a mouse model of Stargardt's macular degeneration.. Proceedings of the National Academy of Sciences of the United States of America, 2004.
- Radu RA, Mata NL, Nusinowitz S, Liu X, Travis GH. Isotretinoin treatment inhibits lipofuscin accumulation in a mouse model of recessive Stargardt's macular degeneration.. Novartis Foundation symposium, 2004.
- Mata NL, Moghrabi WN, Lee JS, Bui TV, Radu RA, Horwitz J, Travis GH. Rpe65 is a retinyl ester binding protein that presents insoluble substrate to the isomerase in retinal pigment epithelial cells.. The Journal of biological chemistry, 2003.
- Radu RA, Mata NL, Nusinowitz S, Liu X, Sieving PA, Travis GH. Treatment with isotretinoin inhibits lipofuscin accumulation in a mouse model of recessive Stargardt's macular degeneration.. Proceedings of the National Academy of Sciences of the United States of America, 2003.
- Mata NL, Radu RA, Clemmons RC, Travis GH. Isomerization and oxidation of vitamin a in cone-dominant retinas: a novel pathway for visual-pigment regeneration in daylight.. Neuron, 2002.