Hostname: page-component-7f64f4797f-vhqbp Total loading time: 0 Render date: 2025-11-04T12:08:22.900Z Has data issue: false hasContentIssue false
  • English
  • Français

Dim background light and Cerenkov radiation from 32P block reversal of rhodopsin phosphorylation in intact frog retinal rods

Published online by Cambridge University Press:  02 June 2009

Michael S. Biernbaum ,
Brad M. Binder  and
M. Deric Bownds
Michael S. Biernbaum
Affiliation:
Laboratory of Molecular Biology, University of Wisconsin, Madison
Brad M. Binder
Affiliation:
Laboratory of Molecular Biology, University of Wisconsin, Madison
M. Deric Bownds
Affiliation:
Laboratory of Molecular Biology and Department of Zoology, University of Wisconsin, Madison
Get access Rights & Permissions [Opens in a new window]

Abstract

The phosphorylation of photoexcited rhodopsin (Rho*) is thought to inactivate this receptor by inhibiting its interaction with the GTP-binding protein transducin (Gt). Here we report that the time course of phosphorylation-dephosphorylation after bright illumination of intact rod outer and inner segments (ROS-RIS) incubated in 33Pi can be altered if the ROS-RIS are first exposed to levels of dim illumination that cause light adaptation in these ROS-RIS. The dephosphorylation of >107 phosphorylated rhodopsin molecules/ROS following a bright flash can be blocked by prior dim continuous illumination (generating 103 Rho*/ROS/s) that cumulatively bleaches ≍ 105 rhodopsin molecules/ROS. The phenomenon has not been previously noted because these low levels of light are emitted as a result of Cerenkov radiation from the 32P isotope that is usually employed to monitor rhodopsin phosphorylation. The inhibition of rhodopsin dephosphorylation by dim conditioning illumination is observed in intact ROS-RIS but is lost when ROS-RIS are electropermeabilized or fragmented.

Keywords

Vertebrate rodsRhodopsin phosphorylationRhodopsin dephosphorylationCerenkov radiationPhosphatase

Information

Type
Short Communications
Information
Visual Neuroscience , Volume 7 , Issue 5 , November 1991 , pp. 499 - 503
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

Baylor, D.A. & Hodgkin, A.L. (1974). Changes in time scale and sensitivity in turtle photoreceptors. Journal of Physiology 242, 729–758.CrossRefGoogle ScholarPubMed
Baylor, D.A., Matthews, G. & Yau, K.-W. (1980). Two components of electrical dark noise in toad retinal rod outer segments. Journal of Physiology 309, 591–621.Google Scholar
Bennett, N. & Sitaramayya, A. (1988). Inactivation of photoexcited rhodopsin in retinal rods: the roles of rhodopsin kinase and 48-kDa protein (arrestin). Biochemistry 27, 1710–1715.CrossRefGoogle ScholarPubMed
Biernbaum, M.S. & Bownds, M.D. (1985a). Frog rod outer segments with attached inner segment ellipsoids as an in vitro model for photoreceptors on the retina. Journal of General Physiology 85, 83–105.CrossRefGoogle Scholar
Biernbaum, M.S. & Bownds, M.D. (1985b). Light-induced changes in GTP and ATP in frog rod photoreceptors: comparison with recovery of dark current and light sensitivity during dark adaptation. Journal of General Physiology 85, 107–121.CrossRefGoogle ScholarPubMed
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, M.D. & Brewer, E. (1986). Changes in protein phosphorylation and nucleoside triphosphates during phototransduction: physiological correlates. In The Molecular Mechanism of Photoreception, ed. Stieve, H., pp. 159–169. Berlin: Springer-Verlag.CrossRefGoogle Scholar
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
Brodie, A.E. & Bownds, D. (1976). Biochemical correlates of adaptation processes in isolated frog photoreceptor membranes. Journal of General Physiology 68, 1–11.CrossRefGoogle ScholarPubMed
Fain, G.L. (1976). Sensitivity of toad rods: dependence on wavelength and background illumination. Journal of Physiology 261, 71–101.Google Scholar
Fowles, C., Akhtar, M. & Cohen, P. (1989). The interplay of phosphorylation and dephosphorylation in vision: protein phosphatases of bovine rod outer segments. Biochemistry 28, 9385–9391.Google Scholar
Fowles, C., Sharma, R. & Akhtar, M. (1988). Mechanistic studies on the phosphorylation of photoexcited rhodopsin. FEBS Letters 238, 56–60.CrossRefGoogle ScholarPubMed
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
Jelley, J.V. (1958). Cerenkov Radiation and Its Applications. New York: Pergamon Press.Google Scholar
Kleinschmidt, J. (1973). Adaptation properties of intracellularly recorded Gekko photoreceptor potentials. In Biochemistry and Physiology of Visual Pigments, ed. Langer, H., pp. 219–224. Berlin: Springer-Verlag.Google Scholar
Kuhn, H. (1974). Light-dependent phosphorylation of rhodopsin in living frogs. Nature 230, 588–590.CrossRefGoogle Scholar
Kuhn, H. & Bader, S. (1976). The rate of rhodopsin phosphorylation in isolated retinas of frog and cattle. Biochimica et Biophysica Acta 428, 13–18.Google Scholar
Kuhn, H., McDowell, J.H., Leser, K.-H., & Bader, S. (1977). Phosphorylation of rhodopsin as a possible mechanism of adaptation. Biophysics of Structure and Mechanism 3, 175–180.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.Google Scholar
Mangini, N.J. & Pepperberg, D.R. (1988). Immunolocalization of 48K in rod photoreceptors. Investigative Ophthalmology and Visual Science 29, 1221–1234.Google ScholarPubMed
Miller, J.A. & Paulsen, R. (1975). Phosphorylation and dephosphorylation of frog rod outer segment membranes as part of the visual process. Journal of Biological Chemistry 250, 4427–4432.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
Palczewski, K., Hargrave, P.A., McDowell, J.H. & Ingebritsen, T.S. (1989a). The catalytic subunit of phosphatase 2A dephosphorylates phosphoopsin. Biochemistry 28, 415–419.CrossRefGoogle ScholarPubMed
Palczewski, K., McDowell, J.H., Jakes, S., Ingebritsen, T.S. & Hargrave, P.A. (1989b). Regulation of rhodopsin dephosphorylation by arrestin. Journal of Biological Chemistry 264, 15770–15773.Google Scholar
Sibley, D.R., Benovic, J.L., Caron, M.G. & Lefkowitz, R.J. (1987). Regulation of transmembrane signaling by receptor phosphorylation. Cell 48, 913–922.Google Scholar
Steidley, K.D., Eastman, R.M. & Stabile, R.J. (1989). Observations of visual sensations produced by Cerenkov radiation from high-energy electrons. International Journal of Radiation Oncology, Biology, and Physics 17, 685–690.CrossRefGoogle Scholar
Weller, M., Virmaux, N. & Mandel, P. (1975). Light stimulates phosphorylation of rhodopsin in the retina: the presence of a protein kinase that is specific for photobleached rhodopsin. Proceedings of the National Academy of Sciences of the U.S.A. 72, 381–385.Google Scholar
Wilden, U., Hall, S.W. & Kuhn, H. (1986). Phosphodiesterase activation by photoexcited rhodopsin is quenched when rhodopsin is phosphorylated and binds the 48 kDa protein of rod outer segments. Proceedings of the National Academy of Sciences of the U.S.A. 83, 1174–1178.Google Scholar