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Molecular determinants of Ca2+ selectivity and ion permeation in L-type Ca2+ channels

Naturevolume 366pages158161 (1993) | Download Citation

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Abstract

VOLTAGE-GATED Ca2+ channels link changes in membrane potential to the delivery of Ca2+, a key second messenger for many cellular responses1. Ca2+ channels show selectivity for Ca2+ over more plentiful ions such as Na+ or K+ by virtue of their high-affinity binding of Ca2+ within the pore2& ndash;6. It has been suggested that this binding involves four conserved glutamate residues7& ndash;10 in equivalent positions in the putative pore-lining regions of repeats I& ndash;IV in the Ca2+ channel & alpha;1 subunit. We have carried out a systematic series of single amino-acid substitutions in each of these positions and find that all four glutamates participate in high-affinity binding of Ca2+ or Cdd2+. Each glutamate carboxylate makes a distinct contribution to ion binding, with the carboxylate in repeat III having the strongest effect. Some single glutamate-to-lysine mutations completely abolish micromolar Ca2+ block, indicating that the pore does not possess any high-affinity binding site that acts independently of the four glutamate residues. The prevailing model of Ca2+permeation2,3 must thus be modified to allow binding of two Ca2+ ions in close proximity11,12, within the sphere of influence of the four glutamates. The functional inequality of the glutamates may be advantageous in allowing simultaneous interactions with multiple Ca2+ ions moving single-file within the pore. Competition among Ca2+ ions for individual glutamates11,12, together with repulsive ion-ion electrostatic interaction2,3, may help achieve rapid flux rates through the channel2& ndash;5.

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References

  1. 1

    Hille, B. Ionic Channels of Excitable Membranes (Sinauer, Sutherland, Massachusetts, 1992).

  2. 2

    Almers, W. & McCleskey, E. W. J. Physiol., Lond. 353, 585–608 (1984).

  3. 3

    Hess, P. & Tsien, R. W. Nature 309, 453–456 (1984).

  4. 4

    Hess, P., Lansman, J. B. & Tsien, R. W. J. gen. Physiol. 88, 293–319 (1986).

  5. 5

    Lansman, J. B., Hess, P. & Tsien, R. W. J. gen. Physiol. 88, 321–347 (1986).

  6. 6

    Rosenberg, R. L. & Chen, X.-H. J. gen. Physiol. 97, 1207–1225 (1991).

  7. 7

    Miller, C. Curr. Biol. 2, 573–575 (1992).

  8. 8

    Tomaselli, G. F., Backx, P. H. & Marban, E. Circulation Res. 72, 491–496 (1993).

  9. 9

    Heinemann, S. H., Terlau, H., Stühmer, W., Imoto, K. & Numa, S. Nature 356, 441–443 (1992).

  10. 10

    Kim, M.-K., Morii, T., Sun, L.-X., Imoto, K. & Mori, Y. FEBS Lett. 318, 145–148 (1993).

  11. 11

    Kuo, C.-C. & Hess, P. J. Physiol., Lond. 466, 629–655 (1993).

  12. 12

    Armstrong, C. M. & Neyton, J. Ann. N.Y. Acad. Sci. 635, 18–25 (1992).

  13. 13

    Mikami, A. et al. Nature 340, 230–233 (1989).

  14. 14

    Kostyuk, P. G., Mironov, S. L. & Shuba, Y. J. Membrane Biol. 76, 83–93 (1983).

  15. 15

    Fukushima, Y. & Hagiwara, S. J. Physiol., Lond. 358, 255–284 (1985).

  16. 16

    Heginbotham, L. & MacKinnon, R. Neuron 8, 483–491 (1992).

  17. 17

    Chow, R. H. J. gen. Physiol. 98, 483–491 (1992).

  18. 18

    Fraústo da Silva, J. J. R. & Williams, R. J. P. The Biological Chemistry of the Elements (Clarendon, Oxford, 1991).

  19. 19

    Zheng, W., Rampe, D. & Triggle, D. J. Molec. Pharmacol. 40, 734–741 (1991).

  20. 20

    Tang, S. et al. J. biol. Chem. 268, 13026–13029 (1993).

  21. 21

    Yool, A. J. & Schwarz, T. L. Nature 349, 700–704 (1991).

  22. 22

    Yellen, G., Jurman, M. E., Abramson, T. & MacKinnon, R. Science 251, 939–942 (1991).

  23. 23

    Hartmann, H. A. et al. Science 251, 942–944 (1991).

  24. 24

    Clarke, D. M., Loo, T. W., Inesi, G. & MacLennan, D. H. Nature 339, 476–478 (1989).

  25. 25

    Kretsinger, R. H. Crit. Rev. Biochem. 8, 119–174 (1980).

  26. 26

    Revah, F. et al. Nature 353, 846–849 (1991).

  27. 27

    Ellis, S. B. et al. Science 241, 1661–1664 (1988).

  28. 28

    Hullin, R. et al. EMBO. J. 11, 885–890 (1992).

  29. 29

    Sather, et al. Neuron 11, 291–303 (1993).

  30. 30

    Meyer, T., Wensel, T. & Stryer, L. Biochemistry 29, 32–37 (1990).

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  1. Department of Molecular and Cellular Physiology, Beckman Center, Stanford University Medical Center, Stanford, California, 94305, USA

    • Jian Yang
    • , Patrick T. Elllnor
    • , William A. Sather
    • , JI-Fang Zhang
    •  & Richard W. Tsien

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https://doi.org/10.1038/366158a0

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