Active Transport of Amino-Acids and Calcium Ions in Fungal Vacuoles
Yeasts are favored model systems of eukaryote cells in investigations on the intracellular compartments of ions and inorganic metabolites. Vacuoles are the largest organelles in yeast cells and they are postulated to function as lysosomes and storage compartments (Matile, 1978; Wiemken and Nurse, 1973; Wiemken and Dürr, 1974; Huber-Wälchli and Wiemken, 1979). We have demonstrated the presence in the vacuolar membrane of the yeast Saccharomyces cerevisiae of an H+-translocating ATPase (Kakinuma et al., 1981; Ohsumi et al., 1985 b; Uchida et al., 1985) and several active transport systems, which are specific for Ca2+ (Ohsumi and Anraku, 1983), arginine (Ohsumi and Anraku, 1981), and other nine amino-acids (Sato et al., 1984 a; Sato et al., 1984 b). Using a preparation of rightside-out vacuolar membrane vesicles of high purity, we showed that the H+-ATPase generates an electrochemical potential difference of protons across the membrane of 180 mV, interior acid (Kakinuma et al., 1981), and that the electrochemical proton gradient formed drives all the above transport by a mechanism of n H+/substrate antiport (Ohsumi and Anraku, 1983; Ohsumi and Anraku, 1981; Sato et al., 1984 a).
KeywordsSaccharomyces Cerevisiae Vacuolar Membrane Active Transport System Electrochemical Proton Gradient Vacuolar Compartment
Unable to display preview. Download preview PDF.
- Cooper, T. G., 1982, Transport in Saccharomyces cerevisiae, in: “The Molecular Biology in the Yeast Saccharomyces: Metabolism and Gene Expression”, J. Strathern, E. W. Jones, and J. R. Broach, eds., Cold Spring Harbor Laboratory, New-York.Google Scholar
- Eddy, A. A., 1980, Some aspects of amino-acid transport in yeast, in: “Microorganisms and Nitrogen Sources”, J. W. Payne, ed., Wiley, Chichester, New-York, Brisbane, Toronto.Google Scholar
- Kitamoto, K., Ohsumi, Y., and Anraku, Y., 1984, Quantitative determination of vacuolar and cytosolic amino-acid pools in Saccharomyces cerevisiae, in: “Abstract of the Annual Meetings of Agricul. Chem. Soc. Japan”.Google Scholar
- Nicholls, D., and Akerman, K., 1982, Mitochondrial calcium transport, Biochim. Biophys. Acta, 683:57.Google Scholar
- Ohsumi, Y., and Anraku, Y., 1987, On the nature of changes induced by cupric ion in the permeability barrier of yeast plasma membrane, Biochim. Biophys. Acta, submitted.Google Scholar
- Ohsumi, Y., Uchida, E., and Anraku, Y., 1985 b, The H+-translocating ATPase in vacuolar membranes of Saccharomyces cerevisiae, in: “Biochemistry and Function of Vacuolar Adenosine-triphosphatase in Fungi and Plants”, B. P. Marin, ed., Springer-Verlag, Berlin, Heidelberg, New-York, and Tokyo.Google Scholar
- Silver, S., 1977, Calcium transport in microrganisms, in: “Microorganisms and Minerals”, E. D. Weinberg, ed., Dekker, New-York.Google Scholar
- Wiemken, A., and Diirr, M., 1974, Characterization of amino-acid pools in the vacuolar compartment of Saccharomyces cerevisiae, Arch. Microbiol., 101:45.Google Scholar