Abstract
IN many cell types an increase in cytosolic calcium is the main signal for the exocytotic release of stored secretory components such as hormones and neurotransmitters. The site of action of calcium in exocytosis is not known, neither are the participating molecules1,2. In the case of the intracellular membrane fusions that occur during transport through early stages of the secretory pathway, several cytosolic and peripheral membrane proteins are necessary3–6. Permeabilized cells have been useful in understanding the requirements for calcium and nucleotides in regulated exocytosis7,8 and under certain conditions there is leakage of soluble protein components and run-down of the exocytotic response9–14. This system can be used to identify the soluble proteins involved in exocytosis, one candidate in chromaffin cells being annexin II (calpactin)9. Here we use this assay to identify two other cytosolic protein factors that regulate exocytosis in permeabilized adrenal chromaffin cells, which we term Exol and Exo2. Exol from brain cytosol resolves on electrophoresis in SDS–polyacrylamide gels as a group of polypeptides of relative molecular mass ˜30,000 and shares sequence homology with the 14–3–3 family of proteins. The ability of Exol to reactivate exocytosis is potentiated by protein kinase C activation and there-fore Exol may influence the protein kinase C-mediated control of Ca2+-dependent exocytosis.
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References
Almers, W. A. Rev. Physiol. 52, 607–624 (1990).
Burgoyne, R. D. Biochim. biophys. Acta. 1071, 174–202 (1991).
Balch, W. E. J. biol. Chem. 264, 16965–16968 (1989).
Clary, D. O., Griff, I. C. & Rothman, J. E. Cell 61, 709–721 (1990).
Wattenberg, B. W., Hiebsch, R. R., LeCureux, L. W. & White, M. P. J. Cell Biol. 110, 947–954 (1990).
Wilson, D. W. et al. Nature 339, 355–359 (1989).
Gomperts, B. D. A. Rev. Physiol 52, 591–606 (1990).
Knight, D. E., von Grafenstein, H. & Athayde, C. M. Trends Neurosci. 12, 451–458 (1989).
Ali, S. M., Geisow, M. J. & Burgoyne, R. D. Nature 340, 313–315 (1989).
Holz, R. W., Bittner, M. A., Peppers, S. C., Senter, R. A. & Eberhard, D. A. J. biol. Chem. 264, 5412–5419 (1989).
Howell, T. W., Kramer, I. M. & Gomperts, B. D. Cell Signal. 1, 157–163 (1989).
Koffer, A. & Gomperts, B. D. J. Cell Sci. 94, 585–591 (1989).
Martin, T. F. J. & Walent, J. H. J. biol. Chem. 264, 10299–10308 (1989).
Sarafian, T., Aunis, D. & Bader, M.-F. J. biol. Chem. 262, 16671–16676 (1987).
Dunn, L. A. & Holz, R. W. J. biol. Chem. 258, 4989–4993 (1983).
Schafer, T., Karli, U. O., Gratwohl, E. K.-M., Schweizer, F. E. & Burger, M. M. J. Neurochem 49, 1696–1707 (1987).
Drust, D. S. & Creutz, C. E. Nature 331, 88–91 (1988).
Nakata, T., Sobue, K. & Hirokawa, N. J. Cell Biol. 110, 13–25 (1990).
Ali, S. M., Geisow, M. J. & Burgoyne, R. D. Cell Signal. 2, 265–276 (1990).
Burgoyne, R. D. & Morgan, A. Biochem. Soc. Trans. 18, 1111–1114 (1990).
Wu, Y. N. & Wagner, P. D. FEBS Lett. 282, 197–199 (1991).
Glenney, J. R., Tack, B. & Powell, M. A. J. Cell Biol. 104, 503–511 (1987).
Burgoyne, R. D., Morgan, A. & O'Sullivan, A. J. FEBS Lett. 238, 151–155 (1988).
Knight, D. E. & Baker, P. F. FEBS Lett. 160, 98–100 (1983).
Pocotte, S. L. et al. Proc. natn. Acad. Sci. U.S.A 82, 930–934 (1985).
Terbush, D. R. & Holz, R. W. J. biol. Chem. 261, 17099–17106 (1986).
Schweizer, F. E. et al. Nature 339, 709–712 (1989).
Block, M. R., Glick, B. S., Wilcox, C. A., Wieland, F. T. & Rothman, J. E. Proc. natn. Acad. Sci. U.S.A. 85, 7852–7856 (1988).
Boston, P. F., Jackson, P. & Thompson, R. J. J. Neurochem. 38, 1475–1482 (1982).
Ichimura, T. et al. Proc. natn. Acad. Sci. U.S.A. 85, 7084–7088 (1988).
Yamanuchi, T., Nakata, H. & Fujisawa, H. J. biol. Chem 256, 5404–5409 (1981).
Toker, A., Ellis, C. A., Sellers, L. A. & Aitken, A. Eur. J. Biochem. 191, 421–429 (1990).
Aitken, A., Ellis, C. A., Harris, A., Sellars, L. A. & Toker, A. Nature 344, 594 (1990).
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Morgan, A., Burgoyne, R. Exol and Exo2 proteins stimulate calcium-dependent exocytosis in permeabilized adrenal chromaff in cells. Nature 355, 833–836 (1992). https://doi.org/10.1038/355833a0
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DOI: https://doi.org/10.1038/355833a0
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