Abstract
Choline acetyltransferase (ChAT) catalyzes synthesis of acetylcholine (ACh) in cholinergic neurons. ACh synthesis is regulated by availability of precursors choline and acetyl coenzyme A or by activity of ChAT; ChAT regulates ACh synthesis under some conditions. Posttranslational phosphorylation is a common mechanism for regulating the function of proteins. Analysis of the primary sequence of 69-kD human ChAT indicates that it has putative phosphorylation consensus sequences for multiple protein kinases. ChAT is phosphorylated on serine-440 and threonine-456 by protein kinase C and CaM kinase II, respectively. These phosphorylation events regulate activity of the enzyme, as well as its binding to plasma membrane and interaction with other cellular proteins. It is relevant to investigate differences in constitutive and inducible patterns of phosphorylation of ChAT under physiological conditions and in response to challenges that cholinergic neurons may be exposed to, and to determine how changes in phosphorylation relate to changes in neurochemical transmission.
Similar content being viewed by others
REFERENCES
Misawa, H., Ishi, K., and Deguchi, T. 1992. Gene expression of mouse choline acetyltransferase: Alternative splicing and identification of a highly active promoter region. J. Biol. Chem. 267:20392–20399.
Oda, Y., Nakanishi, I., and Deguchi, T. 1992. A complementary DNA for human choline acetyltransferase induces two forms of enzyme with different molecular weights in cultured cells. Mol. Brain Res. 16:287–294.
Robert, I. and Quirin-Stricker, C. 2001. A novel untranslated 'exon H' of the human choline acetyltransferase gene in placenta. J. Neurochem. 79:9–16.
Misawa, H., Matsuura, J., Oda, Y., Takahashi, R., and Deguchi, T. 1997. Human choline acetyltransferase mRNAs with different 5′-region produce a 69-kD major translation product. Mol. Brain Res. 44:323–333.
Ohno, K., Tsujino, A., Brengman, J. M., Harper, C. M., Bajzer, Z., Udd, B., Beyring, R., Robb, S., Kirkham, F. J., and Engel, A. G. 2001. Choline acetyltransferase mutations cause myasthenic syndrome associated with apnea in humans. Proc. Nat. Acad. Sci. 98:2017–2022.
Resendes, M. C., Dobransky, T., Ferguson, S. S., and Rylett, R. J. 1999. Nuclear localization of the 82-kD form of human choline acetyltransferase. J. Biol. Chem. 274:19417–19421.
Dobransky, T., Davis, W. L., Xiao, G. H., and Rylett, R. J. 2000. Expression, purification and characterization of recombinant human choline acetyltransferase: Phosphorylation of the enzyme regulates catalytic activity. Biochem. J. 349:141–151.
Tuček, S. 1990. The synthesis of acetylcholine: Twenty years of progress. Prog. Brain Res. 84:467–477.
Hersh, L. B. 1982. Kinetic studies of the choline acetyltransferase reaction using isotope exchange at equilibrium. J. Biol. Chem. 257:12820–12834.
Tuček, S. 1985. Regulation of acetylcholine synthesis in the brain. J. Neurochem. 44:10–24.
Uney, J. B. and Marchbanks, R. M. 1987. Specificity of ethyl-choline mustard aziridinium as an irreversible inhibitor of choline transport in cholinergic and noncholinergic tissue. J. Neurochem. 48:1673–1676.
Pongrac, J. L. and Rylett, R. J. 1996. Differential effects of nerve growth factor on expression of choline acetyltransferase and sodium-coupled choline transport in basal forebrain cholinergic neurons in culture. J. Neurochem. 66:804–810.
Cooke, L. J. and Rylett, R. J. 1997. Inhibitors of serine/threonine phosphatases increase membrane-bound choline acetyltransferase activity and enhance acetylcholine synthesis. Brain Res. 751:232–238.
Rylett, R. J. and Schmidt, B. M. 1993. Regulation of the synthesis of acetylcholine. Prog. Brain Res. 98:161–166.
Collier, B., Tandon, A., Prado, M. A. M., and Bachoo, M. 1993. Storage and release of acetylcholine in a sympathetic ganglion. Prog. Brain Res. 98:183–189.
Tandon, A., Bachoo, M., Weldon, P., Polosa, C., and Collier, B. 1996. Effects of colchicine application to preganglionic axons on choline acetyltransferase activity and acetylcholine content and release in the superior cervical ganglion. J. Neurochem. 66:1033–1041.
Browning, M. D., Huganir, R., and Greengard, P. 1985. Protein phosphorylation and neuronal function. J. Neurochem. 45:11–22.
Schenk, P. W. and Snaar-Jagalska, B. E. 1999. Signal perception and transduction: The role of protein kinases. Biochim. Biophys. Acta 1449:1–24.
Graves, J. D. and Krebs, E. G. 1999. Protein phosphorylation and signal transduction. Pharmacol. Ther. 82:111–121.
Yaffe, M. B. and Cantley, L. C. 1999. Signal transduction: Grabbing phosphoproteins. Nature 402:30–31.
Kumer, S. C. and Vrana, K. E. 1996. Intricate regulation of tyrosine hydroxylase activity and gene expression. J. Neurochem. 67:443–462.
Schmidt, B. M. and Rylett, R. J. 1993. Phosphorylation of rat brain choline acetyltransferase and its relationship to enzyme activity. J. Neurochem. 61:1774–1781.
Bruce, G. and Hersh, L. B. 1989. The phosphorylation of choline acetyltransferase. Neurochem. Res. 14:613–620.
Habert, E., Birman, S., and Mallet, J. 1992. High-level synthesis and fate of acetylcholine in baculovirus-infected cells: Characterization and purification of recombinant rat choline acetyltransferase. J. Neurochem. 58:1447–1453.
Dobransky, T., Davis, W. L., and Rylett, R. J. 2001. Functional characterization of phosphorylation of 69-kD human choline acetyltransferase at serine-440 by protein kinase C. J. Biol. Chem. 276:22244–22250.
Dobransky, T., Brewer, D., Lajoie, G., and Rylett, R. J. 2003. Phosphorylation of 69-kD choline acetyltransferase at threonine-456 in response to short-term exposure to amyloid-β peptide 1–42. J. Biol. Chem. in press.
Yamauchi, T., Nakata, H., and Fujisawa, H. 1981. A new activator protein that activates tryptophan 5-monooxygenase and tyrosine 3-monooxygenase in the presence of Ca2+-, calmodulin-dependent protein kinase: Purification and characterization. J. Biol. Chem. 256:5404–5409.
Ichimura, T., Isobe, T., Okuyama, T., Takahashi, N., Araki, K., Kuwano, R., and Takahashi, Y. 1988. Molecular cloning of cDNA coding for brain-specific 14-3-3 protein, a protein kinase-dependent activator of tyrosine and tryptophan hydroxylases. Proc. Nat. Acad. Sci. 85:7084–7088.
Cozzari, C. and Hartman, B. K. 1983. Choline acetyltransferase: Purification procedure and factors affecting chromatographic properties and enzyme stability. J. Biol. Chem. 258:10013–10019.
Cozzari, C. and Hartman, B. K. 1983. An endogenous inhibitory factor for choline acetyltransferase. Brain Res. 276:109–117.
Andriamampandry, C. and Kanfer, J. N. 1993. Inhibition of cytosolic human forebrain choline acetyltransferase activity by phospho-L-serine: A phosphomonoester that accumulates during early stages of Alzheimer's disease. Neurobiol. Aging 14:367–372.
Singh, I., Xu, C., Pettegrew, J. W., and Kanfer, J. N. 1994. Endogenous inhibitors of human choline acetyltransferase present in Alzheimer's brain: Preliminary observation. Neurobiol. Aging 15:643–649.
Pahud, G., Salem, N., van de Goor, J., Medilanski, J., Pellegrinelli, N., and Eder-Colli, L. 1998. Study of subcellular localization of membrane-bound choline acetyltransferase in Drosophila central nervous system and its association with membranes. Eur. J. Neurosci. 10:1644–1653.
Carroll, P. T., Badamchian, M., Craig, P., and Lyness, W. H. 1986. Veratridine-induced breakdown of cytosolic acetylcholine in rat hippocampal minces: An intraterminal form of acetylcholinesterase or choline O-acetyltransferase? Brain Res. 383:83–99.
Carroll, P. T. 1987. Veratridine-induced activation of choline-O-acetyltransferase activity in rat hippocampal tissue: Relationship to the veratridine-induced release of acetylcholine. Brain Res. 414:401–404.
Pisano, M. R., Wang, H. Y., and Friedmann, E. 1991. Protein kinase activity changes in the aging brain. Biomed. Environ. Sci. 4:173–171.
Clark, E. A., Leach, K. L., Trojanowski, J. Q., and Lee, M. Y. 1991. Characterization and differential distribution of the three major human protein kinase C isozymes (PKC alpha, PKC beta, and PKC gamma) of the central nervous system in normal and Alzheimer's disease brains. Lab. Invest. 64:35–44.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dobransky, T., Jane Rylett, R. Functional Regulation of Choline Acetyltransferase by Phosphorylation. Neurochem Res 28, 537–542 (2003). https://doi.org/10.1023/A:1022873323561
Issue Date:
DOI: https://doi.org/10.1023/A:1022873323561