Abstract
The progressive salinization of irrigated land poses a threat to the future of agriculture in arid regions. The identification of crucial metabolic steps in salt tolerance is important for the understanding of stress physiology and may provide the tools for its genetic engineering. In the yeast Saccharomyces cerevisiae we have isolated a gene, HAL2, which upon increase in gene dosage improves growth under NaCl and LiCl stresses. The HAL2 protein is homologous to inositol phosphatases, enzymes known to be inhibited by lithium salts. Complementation analysis demonstrated that HAL2 is identical to MET22, a gene involved in methionine biosynthesis. Accordingly, methionine supplementation improves the tolerance of yeast to NaCl and LiCl. These results demonstrate an unsuspected interplay between methionine biosynthesis and salt tolerance.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptation, Physiological*
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Amino Acid Sequence
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Base Sequence
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Chlorides / pharmacology*
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DNA, Fungal
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Fungal Proteins / genetics*
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Fungal Proteins / metabolism
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Genetic Complementation Test
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Lithium / pharmacology*
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Lithium Chloride
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Methionine / biosynthesis*
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Molecular Sequence Data
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Nucleotidases / genetics*
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Nucleotidases / metabolism
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Phosphoric Monoester Hydrolases / genetics*
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Phosphoric Monoester Hydrolases / metabolism
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Saccharomyces cerevisiae / drug effects
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Saccharomyces cerevisiae / metabolism
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Saccharomyces cerevisiae / physiology*
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Sequence Homology, Amino Acid
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Sodium Chloride / pharmacology*
Substances
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Chlorides
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DNA, Fungal
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Fungal Proteins
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Sodium Chloride
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Lithium
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Methionine
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Nucleotidases
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Phosphoric Monoester Hydrolases
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myo-inositol-1 (or 4)-monophosphatase
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bisphosphoadenylate 3'-nucleotidase
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Lithium Chloride