email: gfain@ucla.edu
phone: (310) 206-4281
office: 3836 LSB
research interests: Physiology of mammalian photoreceptors
Education
B.A., Biology, Stanford University 1968
Ph.D., Biophysics, Johns Hopkins University 1973
Research Interests
A vertebrate photoreceptor uses a G-protein receptor (rhodopsin) and a G-protein cascade to produce the electrical response that signals a change in light intensity. Powerful new techniques have made it possible to understand the working of this cascade in extraordinary detail. The reason for this is that practically every protein involved in the cascade in a photoreceptor, from the pigment molecule rhodopsin to the G-protein and channels, but including also a large number of control proteins, are expressed only in the photoreceptors and nowhere else in the body. This makes it possible with genetic techniques to create mice in which these proteins have been knocked out, over or under expressed, or replaced with proteins of modified structure. We use electrical recording to study the effects of such genetic alterations on the light responses of mouse rods, in order to understand the role of these proteins in the visual cascade. We are especially interested in modulatory enzymes and their function in light and dark adaptation. We also have a long-standing interest in mechanisms of photoreceptor degeneration in genetically inherited disease. We are presently the only laboratory in the world making measurements of changes in Ca from mouse rods with fluorescent dyes, and our experiments have implicated both increases and decreases in Ca concentration as contributing factors in the triggering of apoptosis.
Selected Publications
Woodruff, M.L., Janisch, K.M., Peshenko, I.V., Dizhoor, A.M., Tsang, S.H., Fain, G.L.. 2008. Modulation of PDE turnoff during background illumination in mouse rod photoreceptors Journal Neuroscience 28 2064-2074 .
Dizhoor, A.M., Woodruff, M.L., Olshevskaya, E.V., Cilluffo, M.C., Cornwall, M.C., Sieving, P.A. and Fain, G.L.. 2008. Night blindness and the mechanism of constitutive signaling of mutant G90D Rhodosin Journal of Neuroscience 28 11662-11672 .
Okawa, H., Sampath, A.P., Laughlin, S.B. and Fain, G.F.. 2008. ATP consumption by mammmalian rod photoreceptors in darkness and in light Current Biology 18 1917-1921 .
Tsang, S.H., Woodruff, M.L., Janisch, K.M., Farber, D.B., Fain, G.L.. 2007. Removal of Phosphorylation Sites of Gamma Subunit of Phosphodiesterase6 Alters Rod Light Response J. Physiol 579 303-312 .
Leung, Y.-T., Fain, G.L., Matthews, H.R.. 2007. Simultaneous measurement of current and calcium in the UV-sensitive cones of zebrafish J. Physiol 579 15-27 .
Woodruff, M.L., Savchenko, A.B., Peshenko, I.V., Olshevskaya, E.V., Barrett, R, Bush, R.A., Sieving, P,A, Fain, G.L., Diazoor, A.M.. 2007. Constitutive excitation by Gly90Asp rhodopsin rescues rods from degeneration caused by elevated production of cyclic GMP in the dark J. Neurosci 27 8805-8815 .
Fain, G.L.. 2006. Why photoreceptors die (and why they don't) Bioessays 28 344-354 .
Tsang, S.H., Woodruff, M.L., Chen, C.K., Yamashita, C.Y., Cilluffo, M.C., Rao, A.L., Farber, D.B., Fain, G.L.. 2006. GAP-Independent termination of photoreceptor light response by excess gamma subunit of the c-GMP-phosphodiesterase J. Neurosci 26 4472-4480 .
Fain, J., Woodruff, M.L., Cilluffo, M.C., Crouch, R.K., Fain G.L.. 2005. Opsin activation of transduction in the rods of dark-reared Rpe65 knockout mice J. Physiol 568 83-95 .
Olshevskaya, E.V., Calvert, P.D., Woodruff, M.L., Peshenko, I.V., Savchenko, A.B., Makino, C.L., Ho, Y.-S., Fain, G.L. & Dizhoor, A.M.. 2004. The Y99C mutation in guanylyl cyclase activating protein 1 increases intracellular free Ca2+ concentration and causes photoreceptor degeneration in transgenic mice Journal of Neuroscience 24 6078-6085 .