Cellular and Molecular Life Sciences CMLS

, Volume 53, Issue 1, pp 69–72

Extracellular Mg2+ regulates intracellular Mg2+ and its subcellular compartmentation in fission yeast, Schizosaccharomyces pombe

Authors

  • A. Zhang
    • Department of Physiology, State University of New York, Health Science Center at Brooklyn, Brooklyn (New York 11203, USA)
  • T. P.-O. Cheng
    • Department of Anatomy and Cell Biology, State University of New York, Health Science Center at Brooklyn, Brooklyn (New York 11203, USA)
  • X. Y. Wu
    • Department of Microbiology and Immunology, State University of New York, Health Science Center at Brooklyn, Brooklyn (New York 11203, USA)
  • B. T. Altura
    • Department of Physiology, State University of New York, Health Science Center at Brooklyn, Brooklyn (New York 11203, USA)
  • B. M. Altura
    • Department of Physiology, State University of New York, Health Science Center at Brooklyn, Brooklyn (New York 11203, USA)

DOI: 10.1007/PL00000581

Cite this article as:
Zhang, A., Cheng, T., Wu, X. et al. CMLS, Cell. mol. life sci. (1997) 53: 69. doi:10.1007/PL00000581

Abstract.

Effects of extracellular magnesium ions ([Mg2+]o ) on intracellular free Mg2+ ([Mg2+]i ) and its subcellular distribution in single fission yeast cells, Schizosaccharomyces pombe, were studied with digital-imaging microscopy and an Mg2+ fluorescent probe (mag-fura-2). Using 0.44 mM [Mg2+]o , [Mg2+]i in yeast cells was 0.91±0.08 mM. Elevation of [Mg2+]o to 1.97 mM induced rapid (within 5 min) increments in [Mg2+]i (2.18±0.11 mM). Lowering [Mg2+]o to 0.06 mM, however, exerted no significant effects on [Mg2+]i (0.93±0.14 mM), at least for periods of up to 30 min. Irrespective of the [Mg2+]o used, the subcellular distribution of [Mg2+]i remained hetero geneous, i.e. where the sub-plasma membrane region >cytoplasm >nucleus. [Mg2+] in all three subcellular compartments increased significantly, two- to threefold, concomitant with [Mg2+]i when placed in 1.97 mM [Mg2+]o . We conclude that [Mg2+]i in fission yeast is maintained at a physiologic level when [Mg2+]o is low, but intracellular free Mg2+ rapidly rises when [Mg2+]o is elevated. Like most eukaryotic cells, yeast may have a Mg2+ transport system(s) which functions to maintain gradients of Mg2+ from the outside to inside the cell and among its subcellular compartments.

Key words. Magnesium; Schizosaccharomyces pombe; mag-fura-2.
Download to read the full article text

Copyright information

© Birkhäuser Verlag Basel, 1997