BACKGROUND: The virulence of Candida species depends on many environmental conditions. Extracellular pH and concentration of alkali metal cations belong among important factors. Nevertheless, the contribution of transporters mediating the exchange of alkali metal cations for protons across the plasma membrane to the cell salt tolerance and other physiological properties of various Candida species has not been studied so far. RESULTS: The tolerance/sensitivity of four pathogenic Candida species to alkali metal cations was tested and the role of one of the cation transporters in that tolerance (presumed to be the plasma-membrane Na+/H+ antiporter) was studied. The genes encoding these antiporters in the most and least salt sensitive species, C. dubliniensis and C. parapsilosis respectively, were identified, cloned and functionally expressed in the plasma membranes of Saccharomyces cerevisiae cells lacking their own cation exporters. Both CpCnh1 and CdCnh1 antiporters had broad substrate specificity and transported Na+, K+, Li+, and Rb+. Their activity in S. cerevisiae cells differed; CpCnh1p provided cells with a much higher salt tolerance than the CdCnh1 antiporter. The observed difference in activity was confirmed by direct measurements of sodium and potassium efflux mediated by these antiporters. CONCLUSION: We have cloned two genes encoding putative Na+/H+ antiporters in C. parapsilosis and C. dubliniensis, and characterized the transport properties of encoded proteins. Our results show that the activity of plasma-membrane Na+/H+ antiporters is one of the factors determining the tolerance of pathogenic Candida species to high external concentrations of alkali metal cations.

• MeSH
• alkalické kovy metabolismus   MeSH
• Candida genetika   růst a vývoj   metabolismus   patogenita   MeSH
• draslík metabolismus   MeSH
• fluorescenční mikroskopie MeSH
• fungální proteiny genetika   metabolismus   MeSH
• kationty metabolismus   MeSH
• lithium metabolismus   MeSH
• membránové proteiny genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• Na(+)-H(+) antiport genetika   metabolismus   MeSH
• proteiny přenášející kationty genetika   metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny genetika   metabolismus   MeSH
• Saccharomyces cerevisiae genetika   růst a vývoj   metabolismus   MeSH
• sekundární struktura proteinů MeSH
• sekvence nukleotidů MeSH
• soli metabolismus   MeSH
• substrátová specifita MeSH
• superoxiddismutasa 1 MeSH
• superoxiddismutasa metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• alkalické kovy MeSH
• CNH1 protein, Candida albicans MeSH Prohlížeč
• draslík MeSH
• fungální proteiny MeSH
• kationty MeSH
• lithium MeSH
• membránové proteiny MeSH
• Na(+)-H(+) antiport MeSH
• NHA1 protein, S cerevisiae MeSH Prohlížeč
• proteiny přenášející kationty MeSH
• Saccharomyces cerevisiae - proteiny MeSH
• soli MeSH
• superoxiddismutasa 1 MeSH
• superoxiddismutasa MeSH