Abstract
The potassium conductance of the squid giant axon is considered the classical example of the delayed rectifier-type of voltage dependent potassium permeability (Hodgkin and Huxley, 1952). In this preparation a large number of experiments have been done on K ionic currents using intact axons and under conditions of internal perfusion to study the selectivity and voltage dependence of the conductance. It has also been possible to record single channel events (Conti and Neher, 1980; Llano and Bezanilla, 1985; Llano, Webb and Bezanilla, 1987) and gating currents related to the movement of the charge responsible for the opening and closing of the K conductance (White and Bezanilla, 1985). The squid giant axon is then an ideal preparation for a detailed analysis of K channel gating because all types of electrophysiological recordings can be made in the same preparation, an important prerequisite for formulating a complete model of channel gating. We review here evidence that the K conductance in the squid axon is modulated by ATP-dependent phosphorylation. The changes induced by ATP in the macroscopic currents appear to be the result of a combined effect on more than one type of K channel. We also provide evidence for a Ca-activated component of the K conductance.
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References
Almers, W., and Armstrong, C. M., 1980, Survival of K+ permeability and gating currents in squid axons perfused with K+-free media, J. Gen. Physiol., 75:61.
Bezanilla, F., Caputo, C., Dipolo, R., and Rojas, H., 1986, Potassium conductance of squid giant axon is modulated by ATP, Proc. Nat. Acad. Sci. U.S.A., 83(8):2743.
Bezanilla, F., Vergara, J., and Taylor, R. E., 1982, Voltage clamping of excitable membranes, in: “Methods of Experimental Physics: Biophysics,” vol. 20, G. Ehrenstein and H. Lecar, eds., Academic Press Inc., London.
Brinley, F. J., and Mullins, L.M., 1967, Sodium extrusion by internally dialyzed squid axons, J. Gen. Physiol., 50:2303.
Conti, F., and Neher, E., 1980, Single channel recordings of K+ currents in squid axons, Nature (Lond), 285:140.
Dipolo, R., Bezanilla, F., Caputo, C., and Rojas, H., 1985, Voltage dependence of the Na/Ca exchange in voltage-clamped, dialyzed squid axons, J. Gen. Physiol., 86:457.
Ewald, D. A., Williams, A., and Levitan, I. B., 1985, Modulation of single Ca2+-dependent K channel activity by protein phosphorylation, Nature, 315:503.
Findlay, I., Dunne, M. J., and Petersen, O. H., 1985, ATP-sensitive inward rectifier and voltage and Calcium-activated K channels in cultured pancreatic islet cells, J. Memb. Biol., 88:165.
Hidaka, H., Inagaki, M., Kawamoto, S., and Sasaki, Y., 1984, Isoquinolinesulfonamides, novel and potent inhibitors of cyclic nucleotide dependent protein kinase and protein kinase C, Biochemistry, 23:5036.
Hodgkin, A. L., and Huxley, A.F., 1952, A quantitative description of membrane current and its application to conduction and excitation in nerve, J. Physiol. (Lond), 117:500.
Kakei, M., Noma, A., and Shibasaki, T., 1985, Properties of adenosinetriphosphate-regulated potassium channels in guinea-pig ventricular cells, J. Physiol., 363:441.
Latorre, R., 1986, The large Ca-activated potassium channel, in: “Ion channel reconstitution,” C. Miller, ed., Plenum, New York.
Llano, I., and Bezanilla, F., 1985, Two types of potassium channels in the cut-open squid giant axon, Biophys. J., 47:221a.
Llano, I., Webb, C. K., and Bezanilla, F., 1987, Two types of unitary potassium channel currents in the squid giant axon, In preparation.
Miller, C., Moczydlowski, E., Latorre, R., and Phillips, M., 1985, Charybdotoxin, a protein inhibitor of single Ca2+-activated K+ channels from mammalian skeletal muscle, Nature, 313:316.
Perozo, E., and Bezanilla, F., 1987a, Intracellular calcium modulates the potassium conductance in dialyzed squid axons, Biophys. J., 51:547a.
Perozo, E., and Bezanilla, F., 1987b, The modulation of K channels in dialyzed squid axons: Effect of intracellular calcium, In preparation.
Perozo, E., Bezanilla, F., Caputo, C., and Dipolo, R., 1987, The modulation of K channels in dialyzed squid axons: ATP mediated phosphorylation, In preparation.
Perozo, E., Dipolo, R., Caputo, C., Rojas, H., and Bezanilla, F., 1986, ATP modification of K currents in dialyzed squid axons, Biophys. J., 49: 215a.
Sherry, S., Goreka, A., Kosoy, M., Debrouska, R., and Hartshore, D., 1978, Roles of calcium and phosphorylation in the regulation of the activity of Gizzard myosin, Biochemistry 17:4411.
Webb, C. K., and Bezanilla, F., 1986, K currents in perfused axons are modified by ATP, Biophys. J., 49:215a.
Webb, C. K., and Bezanilla, F., 1987, Potassium gating currents in the perfused axon are modified by ATP, Biophys. J., 51:547a.
White, M. M., and Bezanilla, F., 1985, Activation of squid axon K channels: Ionic and gating current studies, J. Gen. Physiol., 85:539.
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© 1988 Plenum Press, New York
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Perozo, E., Webb, C.K., Bezanilla, F. (1988). Modulation of the Potassium Conductance in the Squid Giant Axon. In: Grinnell, A.D., Armstrong, D., Jackson, M.B. (eds) Calcium and Ion Channel Modulation. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-0975-8_18
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DOI: https://doi.org/10.1007/978-1-4613-0975-8_18
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