Current Genetics

, Volume 30, Issue 6, pp 476–484

A genetic analysis of the role of calcineurin and calmodulin in Ca++-dependent improvement of NaCl tolerance of Saccharomyces cerevisiae

  • Agneta Danielsson
  • Christer Larsson
  • Katrin Larsson
  • Lena Gustafsson
  • L. Adler
ORIGINAL PAPER

Abstract

Mutants of Saccharomyces cerevisiae lacking activity of the Ca2+/calmodulin-dependent protein phosphatase calcineurin, show sensitivity to high concentrations of sodium that is partly reversed by the external supply of Ca2+. On long-time exposure to NaCl stress the mutants display an increased intracellular Na+/K+ ratio which is partially corrected by the addition of Ca2+, improving the sodium efflux of not only calcineurin-defective cells but also wild-type cells. We also demonstrate that the NaCl sensitivity of cmd mutants, expressing modified forms of calmodulin that do not bind Ca2+, is strongly reversed by the addition of Ca2+. This effect is highly dependent on calcineurin, since the NaCl tolerance of a cmd1-3 strain, carrying an additional mutation in calcineurin, is only slightly assisted by Ca2+. A striking characteristic of the loss of function of calcineurin is a several-fold increased content of intracellular Ca2+, localized mainly in subcellular compartment(s). If the compartmentalized Ca2+ pool is brought back to normal levels by an additional inactivating mutation of the vacuolar Ca2+-transporting ATPase, such double mutants do not significantly improve their tolerance to NaCl.

Key words Calcineurin   Calmodulin   Saccharomyces cerevisiae   Salt tolerance 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • Agneta Danielsson
    • 1
  • Christer Larsson
    • 1
  • Katrin Larsson
    • 1
  • Lena Gustafsson
    • 1
  • L. Adler
    • 1
  1. 1.Department of General and Marine Microbiology, University of Göteborg, Lundberg Laboratory, Medicinaregatan 9C, S-431 90 Göteborg, SwedenSE

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