Gabriel H. Travis

310-267-2673

Office: 

100 Stein Plaza
UCLA School of Medicine
Los Angeles, CA 90095
UNITED STATES

Gabriel H. Travis

Position Titles: 

Professor, Ophthalmology
Professor, Biological Chemistry

Biography: 

Gabriel H. Travis is a biochemist and molecular biologist who has been on the faculty at UCLA in Ophthalmology and Biological Chemistry since 2001. Dr. Travis earned his BS degree in chemistry at UCLA, and his MD at UCLA School of Medicine. After completing a residency in neurology, Dr. Travis left clinical medicine and devote himself full-time to basic research. He completed a postdoctoral fellowship at the UCLA Molecular Biology Institute in 1984 and a second postdoctoral fellowship at Scripps Research Institute in 1989.  He then took a faculty position in Neuroscience at UT Southwestern Medical Center in Dallas, where he remained until moving to UCLA. Dr. Travis currently directs a research group that studies retinoid metabolism in photoreceptor cells, and the mechanisms of inherited blinding diseases. 

Research interest: 

Visual perception begins when a photon is captured by an opsin pigment in a rod or cone cell.  This causes photoisomerization of the retinaldehyde chromophore from 11cRAL to atRAL, converting opsin to its signaling state.  Shortly after, the active opsin decays, releasing free atRAL.  Sensitivity is only restored to the resulting apo-opsin when it combines with another 11cRAL to form a new pigment.  Our laboratory is interested in the biochemical processes that convert atRAL back to 11cRAL.  The genes for several proteins of the visual cycle are affected in human inherited retinal and macular degenerations.  We are working to understand what these proteins normally do for a living, and how loss of function causes blindness in people with disease-causing mutations.  We are also interested in how the visual opsins maintain light sensitivity under daylight conditions where the photon fluxes and hence chromophore-consumption rates are millions-fold higher than at night.  We have discovered several processes that are hugely stimulated by visible light.  The action spectra for these light-induced molecular events provides interesting clues.  We have several exciting projects open to study how natural light exposure affects the dynamics of visual retinoids.  Our lab employs a wide range of methodologies and makes extensive use of genetically modified mice. 

Publications

Kaylor JJ, et al. (2015) Diacylglycerol O-acyltransferase type-1 synthesizes retinyl esters in the retina and retinal pigment epithelium. PloS one 10(5):e0125921.

Kaylor JJ, et al. (2014) Identification of the 11-cis-specific retinyl-ester synthase in retinal Muller cells as multifunctional O-acyltransferase (MFAT). Proc Natl Acad Sci U S A 111(20):7302-7307.

Sato K, et al. (2013) Receptor interacting protein kinase-mediated necrosis contributes to cone and rod photoreceptor degeneration in the retina lacking interphotoreceptor retinoid-binding protein. J Neurosci 33(44):17458-17468.

Kaylor JJ, et al. (2013) Identification of DES1 as a vitamin A isomerase in Muller glial cells of the retina. Nature chemical biology 9(1):30-36.

Mullins RF, et al. (2012) Autosomal recessive retinitis pigmentosa due to ABCA4 mutations: clinical, pathologic, and molecular characterization. Invest Ophthalmol Vis Sci 53(4):1883-1894.

Radu RA, et al. (2011) Complement system dysregulation and inflammation in the retinal pigment epithelium of a mouse model for Stargardt macular degeneration. J Biol Chem 286(21):18593-18601.

Kawaguchi R, et al. (2011) Receptor-mediated cellular uptake mechanism that couples to intracellular storage. ACS chemical biology 6(10):1041-1051.

Blakeley LR, et al. (2011) Rod outer segment retinol formation is independent of Abca4, arrestin, rhodopsin kinase, and rhodopsin palmitylation. Invest Ophthalmol Vis Sci 52(6):3483-3491.

Yuan Q, et al. (2010) Rpe65 isomerase associates with membranes through an electrostatic interaction with acidic phospholipid headgroups. J Biol Chem 285(2):988-999.

Travis GH, Kaylor J, & Yuan Q (2010) Analysis of the retinoid isomerase activities in the retinal pigment epithelium and retina. Methods Mol Biol 652:329-339.

Sun H & Travis GH eds (2010) Retinoids - Methods and Protocols (Humana Press, Hatfield, Hertfordshire, UK), Vol 652.

Linton JD, et al. (2010) Flow of energy in the outer retina in darkness and in light. Proc Natl Acad Sci U S A 107(19):8599-8604.

Liao JL, et al. (2010) Molecular signature of primary retinal pigment epithelium and stem-cell-derived RPE cells. Human molecular genetics 19(21):4229-4238.

Philp AR, et al. (2009) Predicting the pathogenicity of RPE65 mutations. Human mutation 30(8):1183-1188.

Jin M, et al. (2009) The role of interphotoreceptor retinoid-binding protein on the translocation of visual retinoids and function of cone photoreceptors. J Neurosci 29(5):1486-1495.

Radu RA, et al. (2008) Accelerated accumulation of lipofuscin pigments in the RPE of a mouse model for ABCA4-mediated retinal dystrophies following Vitamin A supplementation. Invest Ophthalmol Vis Sci 49(9):3821-3829.

Radu RA, et al. (2008) 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. J Biol Chem 283(28):19730-19738.

Travis GH, Golczak M, Moise AR, & Palczewski K (2007) Diseases Caused by Defects in the Visual Cycle: Retinoids as Potential Therapeutic Agents. Annual review of pharmacology and toxicology 47:469-512.

Jin M, Yuan Q, Li S, & Travis GH (2007) Role of LRAT on the retinoid isomerase activity and membrane association of Rpe65. J Biol Chem 282(29):20915-20924.

Franze K, et al. (2007) Muller cells are living optical fibers in the vertebrate retina. Proc Natl Acad Sci U S A 104(20):8287-8292.

Brill E, et al. (2007) A novel form of transducin-dependent retinal degeneration: accelerated retinal degeneration in the absence of rod transducin. Invest Ophthalmol Vis Sci 48(12):5445-5453.

Bakall B, et al. (2007) Enhanced accumulation of A2E in individuals homozygous or heterozygous for mutations in BEST1 (VMD2). Exp Eye Res 85(1):34-43.

Kaschula CH, Jin MH, Desmond-Smith NS, & Travis GH (2006) Acyl CoA:retinol acyltransferase (ARAT) activity is present in bovine retinal pigment epithelium. Exp Eye Res 82(1):111-121.

Bui TV, Han Y, Radu RA, Travis GH, & Mata NL (2006) Characterization of native retinal fluorophores involved in biosynthesis of A2E and lipofuscin-associated retinopathies. J Biol Chem 281:18112–18119.

Radu RA, et al. (2005) 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 46(12):4393-4401.

Mata NL, Ruiz A, Radu RA, Bui TV, & Travis GH (2005) Chicken retinas contain a retinoid isomerase activity that catalyzes the direct conversion of all-trans-retinol to 11-cis-retinol. Biochemistry 44(35):11715-11721.

Jin M, Li S, Moghrabi WN, Sun H, & Travis GH (2005) Rpe65 is the retinoid isomerase in bovine retinal pigment epithelium. Cell 122(3):449-459.

Radu RA, Mata NL, Nusinowitz S, Liu X, & Travis GH (2004) Isotretinoin treatment inhibits lipofuscin accumulation in a mouse model of recessive Stargardt's macular degeneration. Novartis Found Symp 255:51-63; discussion 63-57, 177-178.

Radu RA, Mata NL, Bagla A, & Travis GH (2004) Light exposure stimulates formation of A2E oxiranes in a mouse model of Stargardt's macular degeneration. Proc. Natl. Acad. Sci. USA 101(16):5928-5933.

Mata NL, et al. (2004) Rpe65 is a retinyl ester binding protein that presents insoluble substrate to the isomerase in retinal pigment epithelial cells. J Biol Chem 279(1):635-643.

Radu RA, et al. (2003) Treatment with isotretinoin inhibits lipofuscin accumulation in a mouse model of recessive Stargardt's macular degeneration. Proc Natl Acad Sci U S A 100(8):4742-4747.

Mata NL, Radu RA, Clemmons R, & Travis GH (2002) Isomerization and oxidation of vitamin a in cone-dominant retinas. A novel pathway for visual-pigment regeneration in daylight. Neuron 36(1):69-80.

Mata NL, et al. (2001) Delayed dark-adaptation and lipofuscin accumulation in abcr+/- mice: implications for involvement of ABCR in age-related macular degeneration. Invest Ophthalmol Vis Sci 42(8):1685-1690.

Kedzierski W, et al. (2001) Deficiency of rds/peripherin causes photoreceptor death in mouse models of digenic and dominant retinitis pigmentosa. Proc Natl Acad Sci U S A 98(14):7718-7723.

Birch DG, et al. (2001) Visual function in patients with cone-rod dystrophy (CRD) associated with mutations in the ABCA4 (ABCR) gene. Exp Eye Res 73(6):877-886.

Nir I, Kedzierski W, Chen J, & Travis GH (2000) Expression of Bcl-2 protects against photoreceptor degeneration in retinal degeneration slow (rds) mice. Journal of Neuroscience 20(6):2150-2154.

Mata NL, Weng J, & Travis GH (2000) Biosynthesis of a major lipofuscin fluorophore in mice and humans with ABCR-mediated retinal and macular degeneration. Proc Natl Acad Sci U S A 97(13):7154-7159.

Weng J, et al. (1999) Insights into the function of Rim protein in photoreceptors and etiology of Stargardt's disease from the phenotype in abcr knockout mice. Cell 98(1):13-23.

Kedzierski W, Weng J, & Travis GH (1999) Analysis of the rds/peripherin.rom1 complex in transgenic photoreceptors that express a chimeric protein. J Biol Chem 274(41):29181-29187.

Kedzierski W, Bok D, & Travis GH (1999) Transgenic analysis of rds/peripherin N-glycosylation: Effect on dimerization, interaction with rom1, and rescue of the rds null phenotype. Journal of neurochemistry 72(1):430-438.

Weng J, Belecky-Adams T, Adler R, & Travis GH (1998) Identification of two rds/peripherin homologs in the chick retina. Invest Ophthalmol Vis Sci 39(2):440-443.

Travis GH (1998) Mechanisms of cell death in the inherited retinal degenerations. American journal of human genetics 62(3):503-508.

Kedzierski W, Bok D, & Travis GH (1998) Non-Cell-Autonomous Photoreceptor Degeneration in Rds Mutant Mice Mosaic For Expression of a Rescue Transgene. Journal of Neuroscience 18(11):4076-4082.

Azarian SM, Megarity CF, Weng J, Horvath DH, & Travis GH (1998) The human photoreceptor rim protein gene (ABCR): genomic structure and primer set information for mutation analysis. Human genetics 102(6):699-705.

Travis GH & Bennett J (1997) The ABCs of AMD. Nature medicine 3(11):1196-1197.

Travis GH (1997) Insights from a lost visual pigment. Nat Genet 15(2):115-117.

Kedzierski W, Lloyd M, Birch DG, Bok D, & Travis GH (1997) Generation and analysis of transgenic mice expressing P216L-substituted rds/peripherin in rod photoreceptors. Invest Ophthalmol Vis Sci 38(2):498-509.

Ferreira PA, Nakayama TA, & Travis GH (1997) Interconversion of red opsin isoforms by the cyclophilin-related chaperone protein Ran-binding protein 2. Proc Natl Acad Sci U S A 94(4):1556-1561.

Azarian SM & Travis GH (1997) The photoreceptor rim protein is an ABC transporter encoded by the gene for recessive Stargardt's disease (ABCR). FEBS Lett 409(2):247-252.

Kedzierski W, et al. (1996) Three homologs of rds/peripherin in Xenopus laevis photoreceptors that exhibit covalent and non-covalent interactions. J Cell Sci 109 ( Pt 10):2551-2560.

Horvath DH, Watson JB, & Travis GH (1996) Probable exclusion of the cortexin-encoding gene as a candidate for mouse neurological mutants: nervous, tottering and motor neuron degeneration. Gene 171(2):305-306.

Ferreira PA, Nakayama TA, Pak WL, & Travis GH (1996) Cyclophilin-related protein RanBP2 acts as chaperone for red/green opsin. Nature 383(6601):637-640.

Moghrabi WN, Kedzierski W, & Travis GH (1995) Canine homolog and exclusion of retinal degeneration slow (rds) as the gene for early retinal degeneration (erd) in the dog. Exp Eye Res 61(5):641-643.

Ma J, et al. (1995) Retinal degeneration slow (rds) in mouse results from simple insertion of a t haplotype-specific element into protein-coding exon II. Genomics 28(2):212-219.

Chowdhury D, Travis GH, Sutcliffe JG, & Burton FH (1995) Synaptotagmin I and 1B4 are identical: implications for synaptotagmin distribution in the primate brain. Neuroscience letters 190(1):9-12.

Carson MR, Travis SM, & Welsh MJ (1995) The two nucleotide-binding domains of cystic fibrosis transmembrane conductance regulator (CFTR) have distinct functions in controlling channel activity. Journal of Biological Chemistry 270(4):1711-1717.

Geiger K, et al. (1994) Transgenic mice expressing IFN-gamma in the retina develop inflammation of the eye and photoreceptor loss. Invest Ophthalmol Vis Sci 35(6):2667-2681.

Travis GH & Hepler JE (1993) A medley of retinal dystrophies. Nat Genet 3(3):191-192.

Groshan KR, Norton JC, Craft CM, & Travis GH (1993) Isolation and characterization of a cDNA for mouse retinal phosducin. Exp Eye Res 57(2):253-255.

Travis GH, Groshan KR, Lloyd M, & Bok D (1992) Complete rescue of photoreceptor dysplasia and degeneration in transgenic retinal degeneration slow (rds) mice. Neuron 9(1):113-119.

Travis GH, Sutcliffe JG, & Bok D (1991) The retinal degeneration slow (rds) gene product is a photoreceptor disc membrane-associated glycoprotein. Neuron 6(1):61-70.

Travis GH, et al. (1991) The human retinal degeneration slow (RDS) gene: chromosome assignment and structure of the mRNA. Genomics 10(3):733-739.

Travis GH (1991) Molecular characterization of the retinal degeneration slow (rds) mutation in mouse. Progress in clinical and biological research 362:87-114.

Sutcliffe JG, et al. (1991) Molecular approaches to genes of the CNS. Epilepsy research. Supplement 4:213-223.

Sutcliffe JG & Travis GH (1991) Molecular-biology approaches to genetic defects of the mammalian nervous system. Progress in nucleic acid research and molecular biology 41:241-258.

Kojis TL, Heinzmann C, Travis GH, Bateman JB, & Sparkes RS (1991) Three polymorphisms detected by a retinal degeneration slow (rds) probe (RDS). Nucleic acids research 19(19):5446.

Kajiwara K, et al. (1991) Mutations in the human retinal degeneration slow gene in autosomal dominant retinitis pigmentosa. Nature 354(6353):480-483.

Lipkin WI, Travis GH, Carbone KM, & Wilson MC (1990) Isolation and characterization of Borna disease agent cDNA clones. Proc Natl Acad Sci U S A 87(11):4184-4188.

Bernal J, Godbout M, Hasel KW, Travis GH, & Sutcliffe JG (1990) Patterns of cerebral cortex mRNA expression. Journal of neuroscience research 27(2):153-158.

Travis GH, Brennan MB, Danielson PE, Kozak CA, & Sutcliffe JG (1989) Identification of a photoreceptor-specific mRNA encoded by the gene responsible for retinal degeneration slow (rds). Nature 338(6210):70-73.

Travis GH & Sutcliffe JG (1988) Phenol emulsion-enhanced DNA-driven subtractive cDNA cloning: isolation of low-abundance monkey cortex-specific mRNAs. Proc Natl Acad Sci U S A 85(5):1696-1700.

Travis GH, Naus CG, Morrison JH, Bloom FE, & Sutcliffe JG (1987) Subtractive cloning of complementary DNAs and analysis of messenger RNAs with regional heterogeneous distributions in primate cortex. Neuropharmacology 26(7B):845-854.

Travis GH, Colavito-Shepanski M, & Grunstein M (1984) Extensive purification and characterization of chromatin-bound histone acetyltransferase from Saccharomyces cerevisiae. J Biol Chem 259(23):14406-14412.