The Arabidopsis thaliana proton transporters, AtNhx1 and Avp1, can function in cation detoxification in yeast

• DOI: 10.1073/pnas.96.4.1480
• Publication Date: 2002-07-26T14:42:40Z
• Authors: Roberto A. Gaxiola; Rajini Rao; Amir Sherman; Paula Grisafi; Seth L. Alper; Gerald R. Fink
• Keywords: 0301 basic medicine; Saccharomyces cerevisiae Proteins; Sodium-Hydrogen Exchangers; Sequence Homology, Amino Acid; Transcription, Genetic; Arabidopsis Proteins; Molecular Sequence Data; Arabidopsis; Saccharomyces cerevisiae; Sodium Chloride; Recombinant Proteins; 03 medical and health sciences; Inactivation, Metabolic; Vacuoles; Humans; Amino Acid Sequence; RNA, Messenger; Cloning, Molecular; Pyrophosphatases; Carrier Proteins; Cation Transport Proteins; Sequence Alignment

Overexpression of the Arabidopsis thaliana vacuolar H + -pyrophosphatase ( AVP1 ) confers salt tolerance to the salt-sensitive ena1 mutant of Saccharomyces cerevisiae . Suppression of salt sensitivity requires two ion transporters, the Gef1 Cl − channel and the Nhx1 Na + /H + exchanger. These two proteins colocalize to the prevacuolar compartment of yeast and are thought to be required for optimal acidification of this compartment. Overexpression of AtNHX1 , the plant homologue of the yeast Na + /H + exchanger, suppresses some of the mutant phenotypes of the yeast nhx1 mutant. Moreover, the level of AtNHX1 mRNA in Arabidopsis is increased in the presence of NaCl. The regulation of AtNHX1 by NaCl and the ability of the plant gene to suppress the yeast nhx1 mutant suggest that the mechanism by which cations are detoxified in yeast and plants may be similar.