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The ligand binding site of the synaptosomal choline transporter: A provisional model based on inhibition studies

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Abstract

A topographic model of the ligand binding site of the choline transporter was deduced from inhibition studies with the help of CPK molecular models. It is posited that there are two identical or closely similar hydrophilic anionic sites separated from each other by an hinged, essentially planar but conformationally flexible cationic hydrophobic domain. Subsequently to attachment of external choline to either one of the anionic sites, both sites cooperate in enveloping the ligand by a Venus fly-trap mechanism. This leads to rapid configurational changes by which the closed-liganded form of the transporter opens up to the interior to release the bound choline. Intracellular K+, a ligand for the choline-binding site, is proposed to be countertransported by a reversal of the above mechanism.

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References

  1. Simon, J. R., Atweh, S., and Kuhar, M. J. 1976. Sodium-dependent high affinity choline uptake: a regulatory step in the synthesis of acetylcholine. J. Neurochem. 26:909–922.

    Google Scholar 

  2. Jope, R. S. 1979. High affinity choline transport and acetylCoA production in brain and their roles in the regulation of acetylcholine synthesis. Brain Res. Rev. 1:313–344.

    Google Scholar 

  3. Lijian, Y., Nishino, H., and Iwashima, A. 1988. Stimulation of choline transport in cultured cells induced by 12-O-tetradecanoylphorbol-13-acetate: one of the earliest phenomena induced by the tumor promoter. Oncology 45:326–330.

    Google Scholar 

  4. Breer, H. 1983. Choline transport by synaptosomal membrane vesicles isolated from insect nervous tissue. FEBS Letters 153:345–348.

    Google Scholar 

  5. Meyer, E. M., and Cooper, J. R. 1982. High-affinity choline transport in proteoliposomes derived from rat cortical synaptosomes. Science 217:843–845.

    Google Scholar 

  6. O'Regan, S., and Vyas, S. 1986. Modifications in choline transport activity as a function of membrane potential and the sodium gradient. J. Physiol., Paris 81:325–331.

    Google Scholar 

  7. Vyas, S., and O'Regan, S. 1985. Reconstitution of carrier-mediated choline transport in proteoliposomes prepared from presynaptic membranes ofTorpedo electric organ, and its internal and external ionic requirements. J. Membrane Biol. 85:111–119.

    Google Scholar 

  8. Meyer, E. M., West, C. M., and Chau, V. 1986, Antibodies directed against ubiquitin inhibit high affinity [3H]choline uptake in rat cerebral cortical synaptosomes. J. Biol. Chem. 261:14365–14368.

    Google Scholar 

  9. Tamaru, M., and Roberts, E. 1988. I. Structure-activity studies on inhibition of choline uptake by a mouse brain synaptosomal preparation: basic data. Brain Res. 473:205–226.

    Google Scholar 

  10. Quiocho, F. A. 1990. Atomic structures of periplasmic binding proteins and the high-affinity active transport systems in bacteria. Phil. Trans. R. Soc. Lond. B 326:341–351.

    Google Scholar 

  11. Deves, R., Reyes, G., and Krupka, R. M. 1986. The carrier reorientation step in erythrocyte choline transport: pH effects and the involvement of a carrier ionizing group. J. Membrane Biol. 93:165–175.

    Google Scholar 

  12. Krupka, R. M., and Deves, R. 1988. The choline carrier of erythrocytes: location of the NEM-reactive thiol group in the inner gated channel. J. Membrane Biol. 101:43–47.

    Google Scholar 

  13. Deves, R., and Krupka, R. M. 1987. Effects on transport of rapidly penetrating, competing substrates: activation and inhibition of the choline carrier in erythrocytes by imidazole. J. Membrane Biol. 99:13–23.

    Google Scholar 

  14. Krupka, R. M. 1989. Testing transport models and transport data by means of kinetic rejection criteria. Biochem. J. 260:885–891.

    Google Scholar 

  15. Mao, B., Pear, M. R., McCammon, J. A., and Quiocho, F. A. 1982. Hinge-bending in L-arabinose-binding protein. J. Biol. Chem. 257:1131–1133.

    Google Scholar 

  16. Vos, J., Kuriyama, K., and Roberts, E. 1968. Electrophoretic mobilities of brain subcellular particles and binding of γ-aminobutyric acid, acetylcholine, norepinephrine, and 5-hydroxytryptamine. Brain Res. 9:224–230.

    Google Scholar 

  17. Kuriyama, K., Roberts, E., and Vos, J. 1968. Some characteristics of binding of γ-aminobutyric acid and acetylcholine to a synaptic vesicle fraction from mouse brain. Brain Res. 9:231–252.

    Google Scholar 

  18. Vos, J., Kuriyama, K., and Roberts, E. 1969. Distribution of acid mucopolysaccharides in subcellular fractions of mouse brain. Brain Res. 12:172–179.

    Google Scholar 

  19. Krupka, R. M., and Deves, R. 1980. The electrostatic contribution to binding in the choline transport system of erythrocytes. J. Biol. Chem. 255:8546–8549.

    Google Scholar 

  20. Deves, R., and Krupka, R. M. 1979. The binding and translocation steps in transport as related to substrate structure. A study of the choline carrier of erythrocytes. Biochim. Biophys. Acta 557:469–485.

    Google Scholar 

  21. Martin, K. 1969. Effects of quaternary ammonium compounds on choline transport in red cells. Br. J. Pharmacol. 36:458–469.

    Google Scholar 

  22. Irwin, M. J., Nyborg, J., Reid, B. R., and Blow, D. M. 1976. The crystal structure of tyrosyl-transfer RNA synthetase at 2.7 Å resolution. J. Mol. Biol. 105:577–586.

    Google Scholar 

  23. Fersht, A. R., Mulvey, R. S., and Koch, G. L. E. 1975. Ligand binding and enzymic catalysis coupled through subunits in tyrosyl-tRNA synthetase. Biochemistry 14:13–18.

    Google Scholar 

  24. Bosshard, H. R., Koch, G. L. E., and Hartley, B. S. 1975. Aminoacyl-tRNA synthetases fromBacillus stearothermophilus. Asymmetry of substrate binding to tyrosyl-tRNA synthetase. Eur. J. Biochem. 53:493–498.

    Google Scholar 

  25. Lindborg, B., Crona, K., and Dahlbom, R. 1984. Troxoniumlike inhibitors of the high affinity uptake of choline in mouse brain synaptosomesin vitro. Acta Pharm. Suec. 21:271–294.

    Google Scholar 

  26. Holden, J. T., Rossier, J., Beaujouan, J. C., Guyenet, P., and Glowinski, J. 1975. Inhibition of high-affinity choline transport in rat striatal synaptosomes by alkyl bisquaternary ammonium compounds. Molecular Pharmacology 11:19–27.

    Google Scholar 

  27. Barker, L. A., and Mittag, T. W. 1975. Comparative studies of substrates and inhibitors of choline transport and choline acetyltransferase. J. Pharm. Exptl. Therap. 192:86–94.

    Google Scholar 

  28. Liron, Z., Wong, E., and Roberts, E. 1988. Studies on uptake of γ-aminobutyric acid by mouse brain particles; toward the development of a model, Brain Res. 444:119–132.

    Google Scholar 

  29. Zilberstein, D., Ophir, I. J., Padan, E., and Schuldiner, S. 1982. Na+ gradient-coupled porters ofEscherichia coli share a common subunit. J. Biol. Chem. 257:3692–3696.

    Google Scholar 

  30. Thom, R. 1975.Structural Stability and Morphogenesis (translated from the French edition, as updated by the author, by D. H. Fowler; Foreword by C. H. Waddington), W. A. Benjamin, Reading, MA.

    Google Scholar 

  31. Martin, K. 1972. Extracellular cations and the movement of choline across the erythrocyte membrane. J. Physiol. 224:207–230.

    Google Scholar 

  32. Saltarelli, M. D., Lowenstein, P. R., and Coyle, J. T. 1987. Rapid in vitro modulation of [3H]hemicholinium-3 binding sites in rat striatal slices. Eur. J. Pharmacol. 135:35–40.

    Google Scholar 

  33. Antonelli, T., Beam, L., Bianchi, C., Pedata, F., and Pepeu, G. 1981. Changes in synaptosomal high affinity choline uptake following electrical stimulation of guinea-pig cortical slices: effect of atropine and physostigmine. Br. J. Pharmacol. 74:525–531

    Google Scholar 

  34. Hatch, G. M., Stevens, W. K., and Choy, P. C. 1988. Effect of amino acids on choline uptake and phosphatidylcholine biosyntehsis in the isolated hamster heart. Biochem. Cell Biol. 66:418–424.

    Google Scholar 

  35. Andresen, P. A., Kaasen, I., Styrvold, O. B., Boulnois, G., and Strom, A. R. 1988. Molecular cloning, physical mapping and expression of thebet genes governing the osmoregulatory choline-glycine betaine pathway ofEscherichia coli. J. Gen. Microbiol. 134:1737–1746.

    Google Scholar 

  36. Nikawa, J.-I., Hosaka, K., Tsukagoshi, Y., and Yamashita, S. 1990. Primary structure of the yeast choline transport gene and regulation of its expression. J. Biol. Chem. 265:15996–16003.

    Google Scholar 

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Special issue dedicated to Dr. Morris H. Aprison.

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Roberts, E., Tamaru, M. The ligand binding site of the synaptosomal choline transporter: A provisional model based on inhibition studies. Neurochem Res 17, 509–528 (1992). https://doi.org/10.1007/BF00969899

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