The translation initiation factor eIF1A is an important determinant in the tolerance to NaCl stress in yeast and plants.
Protein synthesis is very sensitive to NaCl. However, the molecular targets responsible for this sensitivity have not been described. A cDNA library of the halotolerant plant sugar beet was functionally screened in a sodium-sensitive yeast strain. We obtained a cDNA clone (BveIF1A) encoding the eukaryotic translation initiation factor eIF1A. BveIF1A was able to partially complement the yeast eIF1A-deficient strain. Overexpression of the sugar beet eIF1A specifically increased the sodium and lithium salt tolerance of yeast. This phenotype was not accompanied by changes in sodium or potassium homeostasis. Under salt stress conditions, yeast cells expressing BveIF1A presented a higher rate of amino acid incorporation into proteins than control cells. In an in vitro protein synthesis system from wheat germ, the BveIF1A recombinant protein improved translation in the presence of NaCl. Finally, transgenic Arabidopsis plants expressing BveIF1A exhibited increased tolerance to NaCl. These results suggest that the translation initiation factor eIF1A is an important determinant of sodium tolerance in yeast and plants.
Rausell
Antonio
A
Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-CSIC, Spain.
Kanhonou
Rodolphe
R
Yenush
Lynne
L
Serrano
Ramon
R
Ros
Roc
R
D000222:Adaptation, Physiological / Q000187:drug effects* / Q000235:genetics; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics; D027461:Beta vulgaris / Q000187:drug effects / Q000235:genetics; D015977:Eukaryotic Initiation Factor-1 / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005816:Genetic Complementation Test; D018021:Lithium Chloride / Q000494:pharmacology; D008969:Molecular Sequence Data; D009154:Mutation; D010448:Peptide Initiation Factors / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000235:genetics*; D030821:Plants, Genetically Modified; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology*
D015977:Eukaryotic Initiation Factor-1; D010448:Peptide Initiation Factors; D010940:Plant Proteins; C026022:eukaryotic peptide initiation factor-1A; D012965:Sodium Chloride; D018021:Lithium Chloride