Characterization of DhKHA1, a gene coding for a putative Na(+) transporter from Debaryomyces hansenii.
The KHA1 gene from Debaryomyces hansenii has been identified and characterized by heterologous expression in Saccharomyces cerevisiae. The gene is orthologous to ScKHA1, previously reported in S. cerevisiae, and on the basis of the deduced amino acid sequence, DhKha1p can be classified as an Na(+)/H(+) transporter. Reverse transcriptase (RT)-PCR experiments indicated that the expression level of DhKHA1 was not dependent on high pH or on the presence of a high salt level in the growth medium. Overexpression of DhKHA1 in a salt-sensitive S. cerevisiae mutant (ena1-4 nha1 kha1) rendered cells specifically more tolerant to Na(+). In addition, internal K(+) and Na(+) measurements and experiments performed with green fluorescence protein (GFP)-tagged DhKha1p indicated the intracellular localization of this protein when expressed in S. cerevisiae.
Carcía-Salcedo
Raúl
R
Laboratorio de Microbiología Agrícola, Departamento de Microbiología, Universidad de Córdoba, Córdoba, Spain.
Montiel
Vera
V
Calero
Fernando
F
Ramos
José
J
D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D004718:Saccharomycetales / Q000235:genetics / Q000378:metabolism*; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
D027682:Cation Transport Proteins; D017923:Sodium-Hydrogen Exchangers