An Unexpected Connection: Potassium Limitation and Ammonium Toxicity in Yeast
2006
Potassium Limitation and Ammonium Toxicity in Yeast
publication
Evidence: moderate
Author Information
Author(s): David C. Hess, David Botstein
Hypothesis
Ammonium ions leak into yeast cells through potassium channels when potassium is limited.
Conclusion
Yeast experiences ammonium toxicity when potassium is deprived, using amino acids to detoxify.
Supporting Evidence
- In potassium-limited environments, yeast cells showed decreased numbers as ammonium concentration increased.
- High levels of amino acids were found in the medium of ammonium-stressed yeast cells, indicating a detoxification response.
- Engineered yeast strains that allowed more ammonium influx showed greater mortality, supporting the hypothesis of ammonium toxicity.
Takeaway
When yeast doesn't have enough potassium, too much ammonium can be harmful, and the yeast tries to fix this by making amino acids.
Methodology
The study used DNA microarray analysis and liquid chromatography tandem mass spectrometry to investigate gene activity and biochemical contents.
Digital Object Identifier (DOI)
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