Summary
Single channels are observed after incorporation of native vesicles from bovine rod outer segment membranes into planar lipid bilayers. The activity of a single channel in the presence of cGMP is compared to that induced by the analog 8-bromo-cGMP and by cAMP. At +80 mV, K 0.5 is about 3 μm for 8Br-cGMP, 18 μm for cGMP and 740 μm for cAMP. In cAMP, the amplitude of the current is smaller than in cGMP or 8Br-cGMP and depends on the filter cut-off frequency. The open/closed transition rates of the channel are slightly slower with 8Br-cGMP than with cGMP while they are 5 to 10 times faster with cAMP. Addition of Ni2+ ions to either cGMP or cAMP increases the open probability: the open/closed transition rates and amplitude of the current in cAMP are then comparable to those in cGMP. A dual effect of the addition of cAMP on the cGMPor 8Br-cGMP dependent activity previously reported (Furman, R.E., Tanaka, J.C. 1989. Biochemistry 28:2785–2788) is observed with a single channel: addition of subthreshold cAMP concentrations to cGMP (or to 8Br-cGMP) markedly increases P o; addition of cAMP concentrations higher than about 70 μm progressively accelerates the kinetics and reduces the amplitude to values observed in cAMP alone. The results are discussed in relation with the model previously proposed to account for the existence of four current levels (Ildefonse, M., Bennett, N. 1991. J. Membrane Biol. 123:133–147).
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Altenhofen, W., Ludwig, J., Eismann, E., Kraus, W., Bönigk, W., Kaupp, U.B. 1991. Control of ligand specificity in cyclic nucleotide-gated channels from rod photoreceptors and olfactory epithelium. Proc. Natl. Acad. Sci. USA 88:9868–9872
Cohen, A.I., Blazynski, C. 1987. Tryptamine and some related molecules block the accumulation of a light-sensitive pool of cyclic AMP in the dark-adaptated, dark-incubated mouse retina. J. Neurochem. 48:729–737
Cook, N.J., Zeilinger, C., Koch, K.-W., Kaupp, U.B. 1986. Solubilization and functional reconstitution of the cGMP-dependent cation channel from bovine rod outer segments. J. Biol. Chem. 261:17033–17039
Dhallan, R.S., Haynes, L.W., Yau, K.-W. 1990. Openings of single rod cGMP-gated channels induced by cAMP. Biophys. J. 57:367a
Fesenko, E.E., Kolesnikov, S.S., Lyubarsky, A.L. 1985. Induction by cyclic GMP of cationic conductance in plasma membrane of retinal rod outer segment. Nature 313:310–313
Filatov, G.N., Jainazarov, A.B., Kolesnikov, S.S., Lyubarsky, A.L., Fesenko, E.E. 1989. The effect of ATP, GTP and cAMP on the cGMP-dependent conductance of the fragments from frog rod plasma membrane. FEBS Lett. 245:185–188
Furman, R.E., Tanaka, J.C. 1989. Photoreceptor channel activation: Interaction between cAMP and cGMP. Biochemistry 28:2785–2788
Hanke, W., Cook, N.J., Kaupp, U.B. 1988. cGMP-dependent channel protein from photoreceptor membranes: Single channel activity of the purified and reconstituted protein. Proc. Natl. Acad. Sci. USA 85:94–98
Haynes, L.W., Kay, A.R., Yau, K.-W. 1986. Single cyclic GMPactivated channel activity in excised patches of rod outer segment membrane. Nature 321:66–70
Hurwitz, R., Holcombe, V. 1991. Affinity purification of the photoreceptor cGMP-gated cation channel. J. Biol. Chem. 266:7975–7977
Ildefonse, M., Bennett, N. 1991. Single-channel study of the cGMP-dependent conductance of retinal rods from incorporation of native vesicles into planar bilayers. J. Membrane Biol. 123:133–147
Jan, L.Y., Jan, Y.N. 1990. A superfamily of ion channels. Nature 345:672
Kaupp, U.B. 1991. The cyclic nucleotide-gated channels of vertebrate photoreceptors and olfactory epithelium. Trends Neurosci. 14:150–157
Kaupp, U.B., Niidome, T., Tanabe, T., Tereda, S., Bönigk, W., Stühmer, W., Cook, N.J., Kangawa, K., Matsuo, H., Hirose, T., Miyata, T., Numa, S. 1989. Primary structure and functional expression from complementary DNA of the rod photoreceptor cyclic GMP-gated channel. Nature 342:762–766
Kühn, H. 1984. Interactions between photoexcited rhodopsin and light-activated enzymes in rods. In: Progress in Retinal Research. Vol. 3, pp. 123–156. N. Osborne and J. Chader, editors. Pergamon, Oxford-New York
MacKinnon, R. 1991. Using mutagenesis to study potassium channel mechanisms. J. Bioenerg. Biomembr. 23:647–663
Matthews, G. 1987. Single-channel recordings demonstrate that cGMP opens the light-sensitive ion channel of the rod photoreceptor. Proc. Natl. Acad. Sci. USA 84:299–302
Matthews, G., Watanabe, S.-I. 1988. Activation of single ion channels from toad retinal rod inner segments by cyclic GMP: Concentration dependence. J. Physiol. 403:389–405
Pugh, E.N., Jr., Cobbs, W.H. 1986. Visual transduction in vertebrate rods and cones: A tale of two transmitters, calcium and cyclic GMP. Vision Res. 26:1613–1643
Pugh, E.N., Lamb, T.D. 1990. Cyclic GMP and calcium: The internal messengers of excitation and adaptation in vertebrate photoreceptors. Vision Res. 30:1923–1948
Sillen, L.G., Martell, A.E. 1964. In: Stability Constants of Metal-Ion Complexes. Section II: Organic Ligands. A.E. Martell, compiler. Spec. Pub. No. 17, pp. 697–698. Chemical Society, London
Tanaka, J.C., Eccleston, J.F., Furman, R.E. 1989. Photoreceptor channel activation by nucleotide derivatives. Biochemistry 28:2776–2784
Weber, I.T., Shabb, J.B., Corbin, J.D. 1989. Predicted structures of the cGMP binding domains of the cGMP-dependent protein kinase: A key alanine/threonine difference in evolutionary divergence of cAMP and cGMP binding sites. Biochemistry 28:6122–6127
Yau, K.-W., Baylor, D.A. 1989. Cyclic GMP-activated conductance of retinal photoreceptor cells. Annu. Rev. Neurosci. 12:289–327
Zimmerman, A.L., Baylor, D.A. 1986. Cyclic GMP-sensitive conductance of retinal rods consists of aqueous pores. Nature 321:70–72
Zimmerman, A.L., Yamanaka, G., Eckstein, F., Baylor, D.A., Stryer, L. 1985. Interaction of hydrolysis-resistant analogs of cyclic GMP with the phosphodiesterase and light-sensitive channel of retinal rod outer segments. Proc. Natl. Acad. Sci. USA 82:8813–8817
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ildefonse, M., Crouzy, S. & Bennett, N. Gating of retinal rod cation channel by different nucleotides: Comparative study of unitary currents. J. Membarin Biol. 130, 91–104 (1992). https://doi.org/10.1007/BF00233741
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00233741