Research in my laboratory is focused on the identification and characterization of rod and cone photoreceptor cells and elucidation of their role in 1) phototransduction; 2) outer segment structure and renewal; 3) protein trafficking; and 4) retinal degenerative diseases. This information is being used to understand the visual system and develop novel gene and drug based therapeutic treatments to slow or eliminate vision loss resulting from inherited retinal degenerative diseases including macular degeneration, retinitis pigmentosa, Leber Congenital Amaurosis, and X-linked retinoschisis.
To accomplish these goals, we are developing and applying a broad range of current and emerging biochemical, molecular, cellular and physiological techniques. These include the generation and characterization of monoclonal antibodies, novel affinity based protein purification methods, DNA cloning, sequencing and mutagenesis, protein expression in mammalian, insect and bacterial cells, mass spectrometric-based proteomics, generation and characterization of knockout and transgenic mice, HPLC, PCR, confocal scanning microscopy, electron microscopy, electrophoretic and chromatographic separations, immunofluorescence and immunoelectron microscopic labeling techniques, gene therapy, tissue culture, and chemical synthesis and characterization.
Some current projects include: 1) biochemical characterization of the photoreceptor ABC transporter, ABCA4, and elucidation of its role in Stargardt macular degeneration; 2) molecular characterization of RD3 and its role in Leber Congenital Amaurosis Type 12; 3) analysis of binding of RS1 to photoreceptor Na/K ATPase and its role in X-linked retinoschisis; 4) application of gene therapy as a possible treatment for Stargardt macular degeneration, X-linked retinoschisis, and Leber Congenital Amaurosis Type 12; 5) functional characterization and regulation of P4-ATPases; 6) proteomic analysis of photoreceptors and other sensory neurons; 7) identification of proteins involved in outer segment structure and morphogenesis; 8) molecular basis for protein trafficking in rod and cone photoreceptors; and 8) characterization of novel calcium binding proteins in the retina.
As part of our research program, we are collaborating with several laboratories in Canada, U.S. and Europe on various projections.
Current Research and Infrastructure Funding:
National Institutes of Health (NEI)
Canadian Institutes for Health Research (CIHR)
Foundation Fighting Blindness (FFB)
Canada Foundation for Innovation (CFI)
Sharon Steward Foundation
Selected Recent Publications
Min, S.H., Molday, L.L., Seeliger, M.W., Dinculescu, A., Timmers, A.M., Janssen, A., Tonagel, F., Tanimoto, N., Weber, B.H.F., Molday, R.S. and Hauswirth, W.W. Prolonged recovery of retinal structure and function after gene therapy in a Rs1h-deficient mouse model of human X-linked juvenile retinoschisis. Mol. Ther . 12:644-51 (2005).
Molday LL, Wu WW, MoldayRS Retinoschisin (RS1), the protein encoded by the X-linked retinoschisis gene, is anchored to the surface of retinal photoreceptor and bipolar cells through its interactions with a Na/K ATPase-SARM1 complex . J. Biol. Chem 282:32780-32801 (2007).
Dyka FM, Wu WW, Pfeifer TA, Molday LL, Grigliatti TA, Molday RS. Characterization and Purification of the Discoidin Domain-Containing Protein Retinoschisin and Its Interaction with Galactose . Biochemistry .47:9098-106 (2008).
Kwok, M.C.M, Holopainen, J.M., Molday, L.L., Foster, L.J., and Molday, R.S. Proteomics of Photoreceptor Outer Segments Identifies a Subset of SNARE and Rab Proteins Implicated in Membrane Vesicle Trafficking and Fusion Mol. Cell Proteomics 7 : 1053-66 (2008) .
Janssen A, Min SH, Molday LL, Tanimoto N, Seeliger MW, Hauswirth WW, Molday RS, and Weber BH. Effect of late-stage therapy on disease progression in AAV-mediated rescue of photoreceptor cells in the retinoschisin-deficient mouse . MolTher .16:1010-7 (2008).
Zhong M, Molday LL, Molday RS Role of the C-terminus of the photoreceptor ABCA4 transporter in protein folding, function and retinal degenerative diseases . J.Biol. Chem . 284: 3640-9 (2009).
Molday, R.S., Zhong, M. and Quazi, F. The Role of the Photoreceptor ABC Transporter ABCA4 in Lipid Transport and Stargardt Macular Degeneration Biochim.Biophys.Acta . 1791:573-583 (2009).
Coleman JA, Kwok MC, Molday RS . Localization, purification, and functional reconstitution of the P4-ATPase Atp8a2, a phosphatidylserineflippase in photoreceptor disc membranes . J Biol Chem . 284:32670-9 (2009).
Holopainen, J.M., Cheng, C.L., Molday, L.L., Johal, G., Coleman, J., Dyka, F., Hii, T., Ahn, J., Molday, R.S. Interaction and localization of the Retinitis Pigmentosa Protein RP2 and NSF in Retinal Photoreceptor Cells . Biochemistry 49:7439-47 (2010).
Molday RS, Zhang K. Defective lipid transport and biosynthesis in recessive and dominant Stargardt macular degeneration . Prog Lipid Res . 49:476-92. (2010).
Azadi, S., Molday, L.L., Molday, R.S. RD3, the protein associated with Leber Congenital Amaurosis is Required for GuanylateCyclase Trafficking in Photoreceptor Cells . ProcNatlAcad Sci. U.S.A . 107:21158-63 (2010).
Coleman, J.A. and Molday, R.S. Critical Role of the ß-subunit CDC50A in the Stable Expression, Assembly, Subcellular localization, and Lipid Transport Activity of the P4-ATPASE ATP8A2 J. Biol. Chem .286:17205-17216 (2011).