Two genes isolated from Schwanniomyces occidentalis, ENA1 and ENA2, encode P-type ATPases highly homologous to the Na-ATPases of Saccharomyces cerevisiae and complement the Na+ sensitivity of an S. cerevisiae mutant strain lacking its own Na-ATPases. The expression of both ENA1 and ENA2 was highly dependent on a high external pH, but whereas a high pH was sufficient for the expression of ENA2, the expression of ENA1 required a high pH and the presence of Na+. Disruption of ENA1 rendered the cells less tolerant to Na+ than the wild-type strain and decreased their capacity for Na+ extrusion. Disruption of ENA2 did not affect Na+ tolerance, but decreased both the growth at high pH and K+ efflux. We discuss these results and propose that fungal Na-ATPases should be considered alkali cation ATPases. By sequence comparison, we found that fungal Na-ATPases form a homogeneous group that can be distinguished from other cation-pumping P-type ATPases, except from the cta3 Ca-ATPase of Schizosaccharomyces pombe.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|