Hostname: page-component-857557d7f7-8wkb5 Total loading time: 0 Render date: 2025-11-21T01:11:15.831Z Has data issue: false hasContentIssue false
  • English
  • Français

A molecular basis for Weber's law

Published online by Cambridge University Press:  02 June 2009

Stevan M. Dawis
Stevan M. Dawis
Affiliation:
Laboratory of Biophysics, The Rockefeller University, New York
Get access Rights & Permissions [Opens in a new window]

Abstract

A mathematical model is presented that obeys a strong form of Weber's law – over a range of adapting and stimulus intensities, equal contrast stimuli evoke identical responses. To account for the strong Weber's law, the adaptive stage in the proposed model employs a “delayed” reverse reaction along with a power-law input. It is suggested that this Weber's law mechanism is responsible for a slow, voltage-uncorrelated component of adaptation in the vertebrate photoreceptor. A plausible biochemical mechanism is the G-protein cycle with phosphorylation of photoactivated photopigment (and binding of arrestin to the phosphorylated photopigment) as the adaptive process. In an Appendix, features of the general model and implications of a specific biochemical model are examined by computer simulation.

Keywords

Weber's lawTransductionAdaptationGuanine nucleotide binding protein (G-protein)Photoreceptor

Information

Type
Research Articles
Information
Visual Neuroscience , Volume 7 , Issue 4 , October 1991 , pp. 285 - 320
Copyright
Copyright © Cambridge University Press 1991

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

Arshavsky, V.Yu, Antoch, M.P. & Philippov, P.P. (1987). On the role of transducin GTPase in the quenching of a phosphodiesterase cascade of vision. FEBS Letters 224, 19–22.CrossRefGoogle Scholar
Bäckström, A.-C. & Hemilä, S.O. (1979). Dark-adaptation in frog rods: changes in the stimulus-response function. Journal of Physiology (London) 287, 107–125.Google Scholar
Baehr, W., Morita, E.A., Swanson, R.J. & Applebury, M.L. (1982). Characterization of bovine rod outer segment G-protein. Journal of Biological Chemistry 257, 6452–6460.CrossRefGoogle ScholarPubMed
Baron, W.S. & Boynton, R.M. (1974). The primate foveal local electroretinogram: an indicator of photoreceptor activity. Vision Research 14, 495–501.CrossRefGoogle ScholarPubMed
Bastian, B.L. & Fain, G.L. (1979). Light adaptation in toad rods: requirement for an internal messenger which is not calcium. Journal of Physiology (London) 297, 493–520.Google Scholar
Bastian, B.L. & Fain, G.L. (1982). The effects of low calcium and background light on the sensitivity of toad rods. Journal of Physiology (London) 330, 307–329.Google Scholar
Baumgold, J., Cooperman, B.B. & White, T.M. (1989). Relationship between desensitization and sequestration of muscarinic cholinergic receptors in two neuronal cell lines. Neuropharmacology 28, 1253–1261.CrossRefGoogle ScholarPubMed
Baylor, D.A. & Fuortes, M.G.F. (1970). Electrical responses of single cones in the retina of the turtle. Journal of Physiology (London) 207, 77–92.Google Scholar
Baylor, D.A. & Hodgkin, A.L. (1974). Changes in time scale and sensitivity in turtle photoreceptors. Journal of Physiology (London) 242, 729–758.Google Scholar
Baylor, D.A., Hodgkin, A.L. & Lamb, T.D. (1974a). The electrical response of turtle cones to flashes and steps of light. Journal of Physiology (London) 242, 685–727.Google Scholar
Baylor, D.A., Hodgkin, A.L. & Lamb, T.D. (1974b). Reconstruction of the electrical responses of turtle cones to flashes and steps of light. Journal of Physiology (London) 242, 759–791.Google Scholar
Bennett, N. (1982). Light-induced interactions between rhodopsin and the GTP-binding protein. Relation with phosphodiesterase activation. European Journal of Biochemistry 123, 133–139.CrossRefGoogle ScholarPubMed
Bennett, N., Michel-Villaz, M. & Kühn, H. (1982). Light-induced interaction between rhodopsin and the GTP-binding protein. Meta-rhodopsin II is the major photoproduct involved. European Journal of Biochemistry 127, 97–103.CrossRefGoogle Scholar
Bennett, N. & Sitaramayya, A. (1988). Inactivation of photoexcited rhodopsin in retinal rods: the roles of rhodopsin kinase and 48-k Da protein (arrestin). Biochemistry 27, 1710–1715.CrossRefGoogle Scholar
Benovic, J.L., Kühn, H., Weyand, I., Codina, J., Caron, M.G. & Lefkowitz, R.J. (1987). Functional desensitization of the isolated β-adrenergic receptor by the β-adrenergic receptor kinase: potential role of an analog of the retinal protein arrestin (48-k Da protein). Proceedings of the National Academy of Sciences of the U.S.A. 84, 8879–8882.CrossRefGoogle Scholar
Binder, B.M., Biernbaum, M.S. & Bownds, M.D. (1990). Light activation of one rhodopsin molecule causes the phosphorylation of hundreds of others. A reaction observed in electropermeabilized frog rod outer segments exposed to dim illumination. Journal of Biological Chemistry 265, 15333–15340.CrossRefGoogle ScholarPubMed
Bownds, D., Dawes, J., Miller, J. & Stahlman, M. (1972). Phosphorylation of frog photoreceptor membranes induced by light. Nature New Biology 237, 125–127.CrossRefGoogle ScholarPubMed
Bownds, D. & Thomson, D. (1988). Control of the sensitivity and kinetics of the vertebrate photoresponse during light adaptation — calculations from simple molecular models. In Molecular Physiology of Retinal Proteins. Proceedings of the Yamada Conference XXI, ed. Hara, T., pp. 241–246. Osaka, Japan: Japan Scientific Societies Press.Google Scholar
Boynton, R.M. & Whitten, D.N. (1970). Visual adaptation in monkey cones: recordings of late receptor potentials. Science (Washington, DC) 170, 1423–1426.Google Scholar
Broekhuyse, R.M., Tolhuizen, E.F.J., Janssen, A.P.M. & Winkens, H.J. (1985). Light induced shift and binding of S-antigen in retinal rods. Current Eye Research 4, 613–618.CrossRefGoogle ScholarPubMed
Burkhardt, D.A. & Gottesman, J. (1987). Light adaptation and responses to contrast flashes in cones of the walleye retina. Vision Research 27, 1409–1420.CrossRefGoogle ScholarPubMed
Byzov, A.L. & Kusnezova, L.P. (1971). On the mechanisms of visual adaptation. Vision Research (Suppl.) 3, 51–63.CrossRefGoogle Scholar
Chabre, M. (1987). Receptor-G protein precoupling: neither proven nor needed. Trends in Neurosciences 10, 355–356.CrossRefGoogle Scholar
Daly, S.J. & Normann, R.A. (1985). Temporal information processing in cones: effects of light adaptation on temporal summation and modulation. Vision Research 25, 1197–1206.CrossRefGoogle ScholarPubMed
Dawis, S.M. (1978). A model for light adaptation: producing Weber's law with bleaching-type kinetics. Biological Cybernetics 30, 187–193.CrossRefGoogle Scholar
Dawis, S.M. (1979). Light adaptation in cone photoreceptors: the occurrence and significance of unitary adaptive strength. Biological Cybernetics 34, 35–41.CrossRefGoogle ScholarPubMed
Dawis, S.M. (1981). The compression model: a re-examination. Vision Research 21, 1511–1515.CrossRefGoogle Scholar
Dawis, S.M., Graeff, R.M., Heyman, R.A., Walseth, T.F. & Goldberg, N.D. (1988). Regulation of cyclic GMP metabolism in toad photoreceptors: definition of the metabolic events subserving photoexcited and attenuated states. Journal of Biological Chemistry 263, 8771–8785.CrossRefGoogle ScholarPubMed
Dawis, S.M. & Purple, R.L. (1981). Steady state adaptation in the ground squirrel retina: PIII and b-wave intensity-response functions. Vision Research 21, 1169–1180.CrossRefGoogle ScholarPubMed
Dawis, S.M. & Purple, R.L. (1982). Adaptation in cones. A general model. Biophysical Journal 39, 151–155.CrossRefGoogle Scholar
Dawis, S.M., Walseth, T.F., Deeg, M.A., Heyman, R.A., Graeff, R.M. & Goldberg, N.D. (1989). Adenosine triphosphate utilization rates and metabolic pool sizes in intact cells measured by transfer of 18O from water. Biophysical Journal 55, 79–99.CrossRefGoogle ScholarPubMed
Devoe, R.D. (1963). Linear relations between stimulus amplitudes and amplitudes of retinal action potentials from the eye of the wolf spider. Journal of General Physiology 47, 13–32.CrossRefGoogle ScholarPubMed
Dowling, J.E. (1963). Neural and photochemical mechanisms of visual adaptation in the rat. Journal of General Physiology 46, 1287–1301.CrossRefGoogle ScholarPubMed
Dowling, J.E. & Ripps, H. (1972). Adaptation in skate photoreceptors. Journal of General Physiology 60, 698–719.CrossRefGoogle ScholarPubMed
Dratz, E.A., Lewis, J.W., Schaechter, L.E., Parker, K.R. & Kliger, D.S. (1987). Retinal rod GTPase turnover rate increases with concentration: a key to the control of visual excitation? Biochemical and Biophysical Research Communications 146, 379–386.CrossRefGoogle Scholar
Fain, G.L. (1976). Sensitivity of toad rods: dependence on wave-length and background illumination. Journal of Physiology (London) 261, 71–101.Google Scholar
Forti, S., Menini, A., Rispoli, G. & Torre, V. (1989). Kinetics of phototransduction in retinal rods of the newt (Triturus cristatus). Journal of Physiology 419, 265–295.CrossRefGoogle ScholarPubMed
Frank, R.N. (1971). Properties of “neural” adaptation in components of the frog electroretinogram. Vision Research 11, 1113–1123.CrossRefGoogle ScholarPubMed
Frank, R.N., Cavanaugh, H.D., & Kenyon, K.R. (1973). Light-stimulated phosphorylation of bovine visual pigments by adenosine triphosphate. Journal of Biological Chemistry 248, 596–609.CrossRefGoogle ScholarPubMed
Fung, B.K.-K. & Stryer, L. (1980). Photolyzed rhodopsin catalyzes the exchange of GTP for bound GDP in retinal rod outer segments. Proceedings of the National Academy of Sciences of the U.S.A, 77, 2500–2504.CrossRefGoogle Scholar
Fung, B.K.-K., Hurley, J.B. & Stryer, L. (1981). Flow of information in the light-triggered cyclic nucleotide cascade of vision. Proceedings of the National Academy of Sciences of the U.S.A. 78, 152–156.CrossRefGoogle ScholarPubMed
Fuortes, M.G.F. & Hodgkin, A.L. (1964). Changes in time scale and sensitivity in the ommatidia of Limulus. Journal of Physiology (London) 172, 239–263.Google Scholar
GodchauxW., III W., III & Zimmerman, W.F. (1979). Membrane-dependent guanine nucleotide binding and GTPase activities of soluble protein from bovine rod cell outer segments. Journal of Biological Chemistry 254, 7874–7884.CrossRefGoogle ScholarPubMed
Gold, G.H. (1986). Plasma membrane calcium fluxes in intact rods are inconsistent with the “calcium hypothesis.” Proceedings of the National Academy of Sciences of the U.S.A. 83, 1150–1154.CrossRefGoogle ScholarPubMed
Grabowski, S.R., Pinto, L.H. & Pak, W.L. (1972). Adaptation in retinal rods of axolotl: intracellular recordings. Science (Washington, DC) 176, 1240–1243.Google Scholar
Gray-Keller, M.P., Biernbaum, M.S. & Bownds, M.D. (1990). Transducin activation in electropermeabilized frog rod outer segments is highly amplified, and a portion equivalent to phosphodiesterase remains membrane-bound. Journal of Biological Chemistry 265, 15323–15332.CrossRefGoogle Scholar
Green, D.G. (1986). The search for the site of visual adaptation. Vision Research 26, 1417–1429.CrossRefGoogle ScholarPubMed
Greenblatt, R.E. (1983). Adapting lights and lowered extracellular free calcium desensitize toad photoreceptors by differing mechanisms. Journal of Physiology (London) 336, 579–605.Google Scholar
Hagins, W.A. (1972). The visual process: excitatory mechanism in the primary receptor cells. Annual Review of Biophysics and Bioengineering 1, 131–158.CrossRefGoogle ScholarPubMed
Harden, T.K. (1983). Agonist-induced desensitization of the β-adrenergic receptor-linked adenylate cyclase. Pharmacological Reviews 35, 5–32.Google ScholarPubMed
Hecht, S. (1937). Rods, cones, and the chemical basis of vision. Physiological Reviews 17, 239–290.CrossRefGoogle Scholar
Hemilä, S. (1977). Background adaptation in the rods of the frog's retina. Journal of Physiology (London) 265, 721–741.Google Scholar
Hood, D.C. & Hock, P.A. (1975). Light adaptation of the receptors: increment threshold functions for the frog's rods and cones. Vision Research 15, 545–553.CrossRefGoogle ScholarPubMed
Hood, D.C., Hock, P.A. & Grover, B.G. (1973). Dark adaptation of the frog's rods. Vision Research 13, 1953–1963.CrossRefGoogle ScholarPubMed
Huppertz, B., Weyand, I. & Bauer, P.J. (1990). Ca2+-binding capacity of cytoplasmic proteins from rod photoreceptors is mainly due to arrestin. Journal of Biological Chemistry 265, 9470–9475.CrossRefGoogle ScholarPubMed
Kawamura, S. & Murakami, M. (1986). Characterization of the light-induced increase in the Michaelis constant of the cGMP phosphodiesterase in frog rod outer segments. Biochimica et Biophysica Acta 870, 256–266.CrossRefGoogle ScholarPubMed
Kleinschmidt, J. & Dowling, J.E. (1975). Intracellular recordings from gecko photoreceptors during light and dark adaptation. Journal of General Physiology 66, 617–648.CrossRefGoogle ScholarPubMed
Koch, K.-W. & Stryer, L. (1988). Highly cooperative feedback control of retinal rod guanylate cyclase by calcium ions. Nature 334, 64–66.CrossRefGoogle ScholarPubMed
Kondo, H. & Miller, W.H. (1988). Rod light adaptation may be mediated by acceleration of the phosphodiesterase-guanylate cyclase cycle. Proceedings of the National Academy of Sciences of the U.S.A. 85, 1322–1326.CrossRefGoogle ScholarPubMed
Krapivinsky, G.B., Filatov, G.N., Filatova, E.A., Lyubarsky, A.L. & Fesenko, E.E. (1989). Regulation of cGMP-dependent conductance in cytoplasmic membrane of rod outer segments by transducin. FEBS Letters 247, 435–437.CrossRefGoogle ScholarPubMed
Kühn, H. (1974). Light-dependent phosphorylation of rhodopsin in living frogs. Nature 250, 588–590.CrossRefGoogle ScholarPubMed
Kühn, H., Bennett, N., Michel-Villaz, M. & Chabre, M. (1981). Interactions between photoexcited rhodopsin and GTP-binding protein: kinetic and stoichiometric analyses from light-scattering changes. Proceedings of the National Academy of Sciences of the U.S.A. 78, 6873–6877.CrossRefGoogle ScholarPubMed
Kühn, H., Cook, J.H. & Dreyer, W.J. (1973). Phosphorylation of rhodopsin in bovine photoreceptor membranes. A dark reaction after illumination. Biochemistry 12, 2495–2502.CrossRefGoogle ScholarPubMed
Kühn, H. & Dreyer, W.J. (1972). Light dependent phosphorylation of rhodopsin by ATP. FEBS Letters 20, 1–6.CrossRefGoogle ScholarPubMed
Kühn, H., Hall, S.W. & Wilden, U. (1984). Light-induced binding of 48-k Da protein to photoreceptor membranes is highly enhanced by phosphorylation of rhodopsin. FEBS Letters 176, 473–478.CrossRefGoogle Scholar
Kühn, H. & Wilden, U. (1987). Deactivation of photoactivated rhodopsin by rhodopsin-kinase and arrestin. Journal of Receptor Research 7, 283–298.CrossRefGoogle ScholarPubMed
Lamb, T.D., McNaughton, P.A. & Yau, K.-W. (1981). Spatial spread of activation and background desensitization in toad rod outer segments. Journal of Physiology (London) 319, 463–496.Google Scholar
Laughlin, S.B. & Hardie, R.C. (1978). Common strategies for light adaptation in the peripheral visual systems of fly and dragonfly. Journal of Comparative Physiology A 128, 319–340.CrossRefGoogle Scholar
Lefkowitz, R.J., Hausdorff, W.P. & Caron, M.G. (1990). Role of phosphorylation in desensitization of the β-adrenoceptor. Trends in Pharmacological Sciences 11, 190–194.CrossRefGoogle ScholarPubMed
Leibovic, K.N. (1983). Phototransduction in vertebrate rods: an example of the interaction of theory and experiment in neuroscience. IEEE Transactions on Systems, Man, and Cybernetics SMC-13, 732–741.CrossRefGoogle Scholar
Leibovic, K.N., Dowling, J.E. & Kim, Y.Y. (1987). Background and bleaching equivalence in steady-state adaptation of vertebrate rods. Journal of Neuroscience 7, 1056–1063.CrossRefGoogle ScholarPubMed
Liebman, P.A. & PughE.N., Jr. E.N., Jr., (1979). The control of phosphodiesterase in rod disk membranes: kinetics, possible mechanisms, and significance for vision. Vision Research 19, 375–380.CrossRefGoogle ScholarPubMed
Liebman, P.A. & Pugh, E.N. Jr (1980). ATP mediates rapid reversal of cyclic GMP phosphodiesterase activation in visual receptor membranes. Nature 287, 734–736.CrossRefGoogle ScholarPubMed
Liebman, P.A. & Pugh, E.N. Jr (1982). Gain, speed, and sensitivity of GTP binding vs. PDE activation in visual excitation. Vision Research 22, 1475–1480.CrossRefGoogle ScholarPubMed
Lohse, M.J., Benovic, J.L., Codina, J., Caron, M.G. & Lefkowitz, R.J. (1990). β-arrestin: a protein that regulates β-adrenergic receptor function. Science (Washington, DC) 248, 1547–1550.Google Scholar
Macleod, D.I.A. (1978). Visual sensitivity. Annual Review of Psychology 29, 613–645.CrossRefGoogle ScholarPubMed
Maffei, L. & Poppele, R.E. (1967). Frequency analysis of the late receptor potential. Journal of Neurophysiology 30, 993–999.CrossRefGoogle ScholarPubMed
Mangini, N.J. & Pepperberg, D.R. (1988). Immunolocalization of 48K in rod photoreceptors. Light and ATP increase OS labeling. Investigative Ophthalmology & Visual Science 29, 1221–1234.Google ScholarPubMed
Matthews, G. (1985). Spatial spread of light-induced sensitization in rod photoreceptors exposed to low external calcium. Vision Research 25, 733–740.CrossRefGoogle ScholarPubMed
Matthews, H.R., Fain, G.L., Murphy, R.L.W. & Lamb, T.D. (1990). Light adaptation in cone photoreceptors of the salamander: a role for cytoplasmic calcium. Journal of Physiology (London) 420, 447–469.Google Scholar
Matthews, H.R., Murphy, R.L.W., Fain, G.L. & Lamb, T.D. (1988). Photoreceptor light adaptation is mediated by cytoplasmic calcium concentration. Nature 334, 67–69.CrossRefGoogle ScholarPubMed
Matthews, H.R., Torre, V. & Lamb, T.D. (1985). Effects on the photoresponse of calcium buffers and cyclic GMP incorporated into the cytoplasm of retinal rods. Nature 313, 582–585.CrossRefGoogle ScholarPubMed
Meier, K. & Klein, C. (1988). An unusual protein kinase phosphorylates the chemotactic receptor of Dictyostelium discoideum. Proceedings of the National Academy of Sciences of the U.S.A. 85, 2181–2185.CrossRefGoogle ScholarPubMed
Miller, D.L. & Korenbrot, J.I. (1987). Kinetics of light-dependent Cafluxes across the plasma membrane of rod outer segments. A dynamic model of the regulation of the cytoplasmic Ca concentration. Journal of General Physiology 90, 397–425.CrossRefGoogle Scholar
Miller, J.L., Fox, D.A. & Litman, B.J. (1986). Amplification of phosphodiesterase activation is greatly reduced by rhodopsin phosphorylation. Biochemistry 25, 4983–4988.CrossRefGoogle ScholarPubMed
Naka, K.-I., Itoh, M.-A. & Chappell, R.L. (1987). Dynamics of turtle cones. Journal of General Physiology 89, 321–337.CrossRefGoogle ScholarPubMed
Naka, K.I. & Rushton, W.A.H. (1966a). S-potentials from colour units in the retina of fish (Cyprinidae). Journal of Physiology (London) 185, 536–555.Google Scholar
Naka, K.I. & Rushton, W.A.H. (1966b). S-potentials from luminosity units in the retina of fish (Cyprinidae). Journal of Physiology (London) 185, 587–599.Google Scholar
Nakatani, K. & Yau, K.-W. (1988). Calcium and light adaptation in retinal rods and cones. Nature 334, 69–71.CrossRefGoogle ScholarPubMed
Nicol, G.D. & Bownds, M.D. (1989). Calcium regulates some, but not all, aspects of light adaptation in rod photoreceptors. Journal of General Physiology 94, 233–259.CrossRefGoogle Scholar
Normann, R.A. & Anderton, P.J. (1983). The incremental sensitivity curve of turtle cone photoreceptors. Vision Research 23, 1731–1733.CrossRefGoogle ScholarPubMed
Normann, R.A. & Perlman, I. (1979a). The effects of background illumination on the photoresponses of red and green cones. Journal of Physiology (London) 286, 491–507.Google Scholar
Normann, R.A. & Perlman, I. (1979b). Evaluating sensitivity changing mechanisms in light-adapted photoreceptors. Vision Research 19, 391–394.CrossRefGoogle ScholarPubMed
Normann, R.A. & Werblin, F.S. (1974). Control of retinal sensitivity I: Light and dark adaptation of vertebrate rods and cones. Journal of General Physiology 63, 37–61.CrossRefGoogle ScholarPubMed
Palczewski, K., McDowell, J.H., Jakes, S., Ingebritsen, T.S. & Hargrave, P.A. (1989). Regulation of rhodopsin dephosphorylation by arrestin. Journal of Biological Chemistry 264, 15770–15773.CrossRefGoogle ScholarPubMed
Pasino, E. & Marchiafava, P.L. (1976). Transfer properties of rod and cone cells in the retina of the tiger salamander. Vision Research 16, 381–386.CrossRefGoogle ScholarPubMed
Pepperberg, D.R., Kahlert, M., Krause, A. & Hofmann, K.P. (1988). Photic modulation of a highly sensitive, near-infrared light-scattering signal recorded from intact retinal photoreceptors. Proceedings of the National Academy of Sciences of the U.S.A. 85, 5531–5535.CrossRefGoogle ScholarPubMed
Pfister, C., Kühn, H. & Chabre, M. (1983). Interaction between photoexcited rhodopsin and peripheral enzymes in frog retinal rods. Influence on the postmetarhodopsin II decay and phosphorylation rate of rhodopsin. European Journal of Biochemistry 136, 489–499.CrossRefGoogle ScholarPubMed
Ratto, G.M., Payne, R., Owen, W.G. & Tsien, R.Y. (1988). The concentration of cytosolic free calcium in vertebrate rod outer segments measured with fura-2. Journal of Neuroscience 8, 3240–3246.CrossRefGoogle ScholarPubMed
Reneke, J.E., Blumer, K.J., Courchesne, W.E. & Thorner, J. (1988). The carboxy-terminal segment of the yeast α-factor receptor is a regulatory domain. Cell 55, 221–234.CrossRefGoogle ScholarPubMed
Schnapf, J.L., Nunn, B.J., Meister, M. & Baylor, D.A. (1990). Visual transduction in cones of the monkey (Macaca fascicularis). Journal of Physiology 427, 681–713.CrossRefGoogle ScholarPubMed
Shapley, R. & Enroth-Cugell, C. (1984). Visual adaptation and retinal gain controls. Progress in Retinal Research 3, 263–346.CrossRefGoogle Scholar
Shichi, H., Yamamoto, K. & Somers, R.L. (1984). GTP binding protein: properties and lack of activation by phosphorylated rhodopsin. Vision Research 24, 1523–1531.CrossRefGoogle ScholarPubMed
Shinohara, T., Dietzschold, B., Craft, C.M., Wistow, G., Early, J.J., Donoso, L.A., Horwitz, J. & Tao, R. (1987). Primary and secondary structure of bovine retinal S antigen (48-k Da protein). Proceedings of the National Academy of Sciences of the U.S.A. 84, 6975–6979.CrossRefGoogle Scholar
Sitaramayya, A. & Liebman, P.A. (1983). Phosphorylation of rhodopsin and quenching of cyclic GMP phosphodiesterase activation by ATP at weak bleaches. Journal of Biological Chemistry 258, 12106–12109.CrossRefGoogle ScholarPubMed
Sneyd, J. & Tranchina, D. (1989). Phototransduction in cones: an inverse problem in enzyme kinetics. Bulletin of Mathematical Biology 51, 749–784.CrossRefGoogle ScholarPubMed
Strong, J. & Lisman, J. (1978). Initiation of light adaptation in barnacle photoreceptors. Science (Washington, DC) 200, 1485–1487.Google Scholar
Stryer, L. (1988). Molecular basis of visual excitation. Cold Spring Harbor Symposia on Quantitative Biology 53, 283–294.CrossRefGoogle ScholarPubMed
Tamura, T., Nakatani, K. & Yau, K.-W. (1989). Light adaptation in cat retinal rods. Science (Washington, DC) 245, 755–758.Google Scholar
Ting, T.D. & Ho, Y.-K. (1989). Molecular mechanism of GTP hydrolysis by transducin. Investigative Ophthalmology & Visual Science (ARVO Suppl.) 30, 172.Google Scholar
Torre, V., Matthews, H.R. & Lamb, T.D. (1986). Role of calcium in regulating the cyclic GMP cascade of phototransduction in retinal rods. Proceedings of the National Academy of Sciences of the U.S.A. 83, 7109–7113.CrossRefGoogle ScholarPubMed
Toyoda, J.-I. (1974). Frequency characteristics of retinal neurons in the carp. Journal of General Physiology 63, 214–234.CrossRefGoogle ScholarPubMed
Tranchina, D., Gordon, J. & Shapley, R.M. (1984). Retinal light adaptation—evidence for a feedback mechanism. Nature 310, 314–316.CrossRefGoogle ScholarPubMed
Tranchina, D. & Peskin, C.S. (1988). Light adaptation in the turtle retina: embedding a parametric family of linear models in a single nonlinear model. Visual Neuroscience 1, 339–348.CrossRefGoogle Scholar
Valeton, J.M. (1983). Photoreceptor light adaptation models: an evaluation. Vision Research 23, 1549–1554.CrossRefGoogle ScholarPubMed
Valeton, J.M. & van, Norren D. (1983). Light adaptation of primate cones: an analysis based on extracellular data. Vision Research 23, 1539–1547.CrossRefGoogle ScholarPubMed
Van, Haastert P.J.M. & Van der Heijden, P.R. (1983). Excitation, adaptation, and deadaptation of the cAMP-mediated cGMP response in Dictyostelium discoideum. Journal of Cell Biology 96, 347–353.Google Scholar
Vaughan, R.A. & Devreotes, P.N. (1988). Ligand-induced phosphorylation of the cAMP receptor from Dictyostelium discoideum. Journal of Biological Chemistry 263, 14538–14543.CrossRefGoogle ScholarPubMed
Vuong, T.M. & Chabre, M. (1990). Subsecond deactivation of transducin by endogenous GTP hydrolysis. Nature 346, 71–74.CrossRefGoogle ScholarPubMed
Wagner, R., Ryba, N. & Uhl, R. (1988). Sub-second turnover of transducin GTPase in bovine rod outer segments. A light scattering study. FEBS Letters 234, 44–48.CrossRefGoogle ScholarPubMed
Weller, M., Goridis, C., Virmaux, N. & Mandel, P. (1975). A hypothetical model for the possible involvement of rhodopsin phosphorylation in light and dark adaptation in the retina. Experimental Eye Research 21, 405–408.CrossRefGoogle ScholarPubMed
Wessling-Resnick, M. & Johnson, G.L. (1987a). Allosteric behavior in transducin activation mediated by rhodopsin. Initial rate analysis of guanine nucleotide exchange. Journal of Biological Chemistry 262, 3697–3705.CrossRefGoogle ScholarPubMed
Wessling-Resnick, M. & Johnson, G.L. (1987b). Transducin interactions with rhodopsin. Evidence for positive cooperative behavior. Journal of Biological Chemistry 262, 12444–12447.CrossRefGoogle ScholarPubMed
Wheeler, G.L. & Bitensky, M.W. (1977). A light-activated GTPase in vertebrate photoreceptors: regulation of light-activated cyclic GMP phosphodiesterase. Proceedings of the National Academy of Sciences of the U.S.A. 74, 4238–4242.CrossRefGoogle ScholarPubMed
Wilden, U., Hall, S.W. & Kühn, H. (1986). Phosphodiesterase activation by photoexcited rhodopsin is quenched when rhodopsin is phosphorylated and binds the intrinsic 48-k Da protein of rod outer segments. Proceedings of the National Academy of Sciences of the U.S.A. 83, 1174–1178.CrossRefGoogle Scholar
Williams, T.P. & Gale, J.G. (1977). A critique of an incremental threshold function. Vision Research 17, 881–882.CrossRefGoogle ScholarPubMed
Witkovsky, P., Nelson, J. & Ripps, H. (1973). Action spectra and adaptation properties of carp photoreceptors. Journal of General Physiology 61, 401–423.CrossRefGoogle ScholarPubMed
Yamada, T., Takeuchi, Y., Komori, N., Kobayashi, H., Sakai, Y., Hotta, Y. & Matsumoto, H. (1990). A 49-kilodalton phospho-protein in the Drosophila photoreceptor is an arrestin homolog. Science (Washington, DC) 248, 483–486.Google ScholarPubMed
Yamaki, K., Takahashi, Y., Sakuragi, S. & Matsubara, K. (1987). Molecular cloning of the S-antigen cDNA from bovine retina. Biochemical and Biophysical Research Communications 142, 904–910.CrossRefGoogle ScholarPubMed
Yamaki, K., Tsuda, M. & Shinohara, T. (1988). The sequence of human retinal S-antigen reveals similarities with α-transducin. FEBS Letters 234, 39–43.CrossRefGoogle ScholarPubMed
Yau, K.-W. & Nakatani, K. (1985). Light-induced reduction of cytoplasmic free calcium in retinal rod outer segment. Nature 313, 579–582.CrossRefGoogle ScholarPubMed
Yoshikami, S. & Hagins, W.A. (1971). Light, calcium, and the photocurrent of rods and cones. Biophysical Society Abstracts 11, 47a.Google Scholar
Zuckerman, R. & Cheasty, J.E. (1986). A 48-k Da protein arrests cGMP phosphodiesterase activation in retinal rod disk membranes. FEBS Letters 207, 35–41.CrossRefGoogle Scholar