Two classes of plant cDNA clones differentially complement yeast calcineurin mutants and increase salt tolerance of wild-type yeast

• Published in: The Journal of biological chemistry Vol. 271; no. 22; pp. 12859 - 12866
• Main Authors: Lippuner, V. (Swiss Federal Institute of Technology Zuerich, Zuerich, Switzerland.), Cyert, M.S, Gasser, C.S
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 31.05.1996
• Subjects: Adaptation, Physiological - genetics; ADN; Amino Acid Sequence; Arabidopsis - genetics; Arabidopsis Proteins; ARABIDOPSIS THALIANA; Base Sequence; Blotting, Southern; Calcineurin; Calmodulin-Binding Proteins - genetics; Cloning, Molecular; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; DNA, Complementary; ESTERASAS; ESTERASE; Genetic Complementation Test; Molecular Sequence Data; Mutation; Phosphoprotein Phosphatases - genetics; Plant Proteins - genetics; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - physiology; Salts; SECUENCIA NUCLEOTIDICA; Sequence Homology, Amino Acid; SEQUENCE NUCLEOTIDIQUE; TRANSFORMACION GENETICA; TRANSFORMATION GENETIQUE
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.271.22.12859

The salt-sensitive phenotype of yeast cells deficient in the phosphoprotein phosphatase, calcineurin, was used to identify genes from the higher plant Arabidopsis thaliana that complement this phenotype. cDNA clones corresponding to two different sequences, designated STO (salt tolerance) and STZ (salt tolerance zinc finger), were found to increased tolerance of calcineurin mutants and of wild-type yeast to both Li+ and Na+ ions. STZ is related to Cys2/His2-type zinc-finger proteins found in higher plants, and STO is similar to the Arabidopsis CONSTANS protein in regions that may also be zinc fingers. Although neither protein has sequence similarity to any protein phosphatase, STO was able to at least partially compensate for all tested additional phenotypic effects of calcineurin deficiency, and STZ compensated for a subset of these effects. Salt tolerance produced by STZ appeared to be partially dependent on ENA1/PMR2, a P-type ATPase required for Li+ and Na+ efflux in yeast, whereas the effect of STO on salt tolerance was independent of ENA1/PMR2. STZ and STO were found to be expressed in Arabidopsis roots and leaves, whereas only STO message was detectable in flowers. An apparent increase in the level of STZ mRNA was observed in response NaCl exposure in Arabidopsis seedlings, but the level of STO mRNA was not altered by this treatment