1887

Abstract

The calcium requirement for optimal growth of is between 0·05 and 2·5 m. Media without Ca will not support growth though Ca-chelating agents, such as EDTA and EGTA, do not have any marked effect on Ca availability at the low pH used to culture this organism. The intracellular Ca concentration varies approximately 10-fold when the external Ca concentration is varied between 0·05 and 25 m. Ca is concentrated in the mitochondrial and microsomal fractions, but the high concentration found in the cytosol suggests that considerable redistribution of Ca occurs during disruption and fractionation of the plasmodia. Ca uptake by intact microplasmodia occurs at rates which are comparable to those required for Ca uptake during growth and generation of new cell mass. This uptake process has two components: one non-saturable with Ca, and the other saturable with an apparent maximum velocity of 67 nmol Ca h (mg protein) and an apparent of 1·9 m-Ca. As judged by [H]inulin uptake, part of the Ca uptake may be endocytotic.

Ionophores A23187 and Br-X537A stimulate Ca uptake. Uptake is inhibited by KCl, Mn and Sr at high concentrations, but is not sensitive to La at concentrations similar to Ca in the uptake medium. KCN and iodoacetic acid inhibit the transport, while cyto-chalasin B, verapamil, tetracaine and procaine have little or no effect.

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1979-08-01
2024-12-07
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References

  1. Balk S.D., Whitfield J.F., Youdale Y., Braun A.C. 1973; Roles of calcium, serum, plasma and folic acid in the control of proliferation of normal and Rous sarcoma virus-infected chicken fibroblasts. Proceedings of the National Academy of Sciences of the United States of Americala 70:675–679
    [Google Scholar]
  2. Berridge M.J. 1975; The interaction of cyclic nucleotides and calcium in the control of cellular activity. Advances in Cyclic Nucleotide Research 6:1–98
    [Google Scholar]
  3. Borle A.B. 1973; Calcium metabolism at the cellular level. Federation Proceedings 32:1944–1950
    [Google Scholar]
  4. Bowers B., Olszewski T.E. 1972; Pinocytosis in Acanthamoeba castellanii.Kinetics and morphology. Journal of Cell Biology 53:681–694
    [Google Scholar]
  5. Camp W.G. 1936; A method of cultivating myxomycete plasmodia. Bulletin of the Torrey Botanical Club 63:206–210
    [Google Scholar]
  6. Carlile M.J. 1971; Myxomycetes and other slime moulds. Methods in Microbiology 4:237–265
    [Google Scholar]
  7. Daniel J.W., Rusch H.P. 1961; The pure culture of Physarum polycephalum on a partially defined soluble medium. Journal of General Microbiology 25:47–59
    [Google Scholar]
  8. Daniel J.W., Baldwin H.H. 1964; Methods of culture for plasmodial myxomycetes. Methods in Cell Physiology 1:9–41
    [Google Scholar]
  9. Daniel J.W., Jarlfors U. 1972; Plasmodial ultrastructure of the myxomycete Physarum polycephalum. Tissue and Cell 4:15–36
    [Google Scholar]
  10. Dee J., Wheals A.E., Holt C.E. 1973; Inheritance of plasmodial valine requirement in Physarum polycephalum. Genetical Research 21:87–101
    [Google Scholar]
  11. Duffus J.H., Patterson L.J. 1974; Control of celt division in yeast using the ionophore A23187 with calcium and magnesium. Nature; London: 251626–627
    [Google Scholar]
  12. Flaschka H.A. 1964 EDTA Titrations. Oxford: Pergamon Press.;
    [Google Scholar]
  13. Guttes E., Guttes S. 1964; Mitotic synchrony in the plasmodia of Physarum polycephalum and mitotic synchronization by coalescence of microplasmodia. Methods in Cell Physiology 1:43–54
    [Google Scholar]
  14. Hatano S. 1970; Specific effect of Ca2+ on movement of plasmodial fragments obtained by caffeine treatment. Experimental Cell Research 61:199–203
    [Google Scholar]
  15. Holmes R.P., Stewart P.R. 1977; Calcium uptake during mitosis in the myxomycete Physarum polycephalum. Nature; London: 269592–594
    [Google Scholar]
  16. Holmes R.P., Stewart P.R. 1979; The isolation of coupled mitochondria from Physarum polycephalum and their response to Ca2+. Biochimica et biophysica acta 545:94–105
    [Google Scholar]
  17. Jafferji S.S., Mitchell R.H. 1976; Effects of calcium-antagonistic drugs on the stimulation by carbamoylcholine and histamine of phosphatidylinositol turnover in longitudinal smooth muscle of guinea-pig ileum. Biochemical Journal 160:163–169
    [Google Scholar]
  18. Kato T., Tonomura Y. 1977; Uptake of calcium ions into microsomes isolated from Physarum polycephalum. Journal of Biochemistry 81:207–213
    [Google Scholar]
  19. Nagai R., Ishima Y., Kikita F., Takenaka T. 1975; Calcium and magnesium contents of ectoplasm and endoplasm of Physarum polycephalum plasmodium. Protoplasma 86:169–174
    [Google Scholar]
  20. Pfeiffer D.R., Lardy H.A. 1976; Ionophore A23187: the effect of H+ concentration on complex formation with divalent and monovalent cations and the demonstration of K+ transport in mitochondria mediated by A23187. Biochemistry 15:935–943
    [Google Scholar]
  21. Rasmussen H. 1975; Ions as “second messengers”. In Cell Membranes in Biochemistry, Cell Biology and Pathology pp. 203–212 Weismann G., Clairborne R. Edited by New York: H.P. Publishing.;
    [Google Scholar]
  22. Ridgway E.B., Durham A.C.H. 1976; Oscillations of calcium ion concentrations in Physarum polycephalum. Journal of Cell Biology 69:223–226
    [Google Scholar]
  23. Truter M.R. 1976; Chemistry of the calcium ionophores. Symposia of the Society for Experimental Biology 30:19–40
    [Google Scholar]
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