A new Alkalitolerant Yarrowia lipolytica yeast strain is a promising model for dissecting properties and regulation of Na+ -dependent phosphate transport systems.
A newly isolated osmo-, salt-, and alkalitolerant Yarrowia lipolytica yeast strain is distinguished from other yeast species by its capacity to grow vigorously at alkaline pH values (9.7), which makes it a promising model organism for studying Na+-dependent phosphate transport systems in yeasts. Phosphate uptake by Y. lipolytica cells grown at pH 9.7 was mediated by several kinetically discrete Na+-dependent systems specifically activated by Na+. One of these, a low-affinity transporter, operated at high concentrations of extracellular phosphate. The other two, high-affinity systems, maximally active in phosphate-starved cells, were repressed or derepressed depending on the prevailing extracellular phosphate concentration and pH value. The contribution of Na+/P(i)-cotransport systems to the total cellular phosphate uptake progressively increased with increasing pH, reaching its maximum at pH >/= 9.
Zvyagilskaya
R A
RA
Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow 119071, Russia. renata_z@inbi.ras.ru
Persson
B L
BL
D000468:Alkalies / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters / Q000502:physiology*; D025062:Yarrowia / Q000378:metabolism*
D000468:Alkalies; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters