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Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions
13:55

Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions

Published on: April 19, 2013

Polyamines improve Ca2+ transport system of the yeast mitochondria

T V Votyakova1, E N Bazhenova, R A Zvjagilskaya

  • 1A.N. Bach Institute of Biochemistry, Academy of Sciences of the USSR, Moscow.

FEBS Letters
|February 12, 1990
PubMed

Insights

Spermine significantly enhances yeast mitochondrial calcium (Ca2+) transport, enabling mitochondria to regulate cellular Ca2+ levels. This polyamine boosts Ca2+ uptake rates, suggesting a key role in cytoplasmic and matrix Ca2+ homeostasis.

Area of Science:

  • Cell Biology
  • Biochemistry
  • Mitochondrial Function

Background:

  • Mitochondria play crucial roles in cellular calcium homeostasis.
  • The regulation of intracellular calcium (Ca2+) levels is vital for various cellular processes.
  • Polyamines are known to influence cellular functions, but their specific impact on mitochondrial Ca2+ transport requires further elucidation.

Purpose of the Study:

  • To investigate the effect of spermine and spermidine on the calcium (Ca2+) transport system in Endomyces magnusii yeast mitochondria.
  • To determine the role of polyamines in regulating extramitochondrial and matrix Ca2+ concentrations.
  • To assess the impact of these polyamines on mitochondrial energy coupling parameters.

Main Methods:

  • Mitochondrial Ca2+ uptake assays were performed using isolated Endomyces magnusii mitochondria.
  • The influence of varying concentrations of spermine and spermidine on Ca2+ transport rates was measured.
  • Parameters of energy coupling in mitochondria were analyzed in the presence of polyamines.

Main Results:

  • Spermine, at concentrations of 12-100 microM, significantly activated the Ca2+ transport system in yeast mitochondria.
  • Spermine enhanced the initial rate of Ca2+ uptake, reducing the Ca2+ concentration required for half-maximal uptake.
  • Spermidine was less effective than spermine in activating Ca2+ transport, and polyamines did not alter mitochondrial energy coupling.

Conclusions:

  • Yeast mitochondria, particularly in the presence of spermine, can effectively regulate extramitochondrial calcium (Ca2+) to physiological levels.
  • Spermine significantly enhances mitochondrial Ca2+ uptake, indicating its importance in managing cellular Ca2+ dynamics.
  • These findings suggest that yeast mitochondria actively participate in the regulation of both cytoplasmic and matrix Ca2+ concentrations.

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