21406243
not annotated - annotated - LINNAEUS only
Potassium and sodium uptake systems in fungi. The transporter diversity of Magnaporthe oryzae.
In this study, we report an inventory of the K(+) uptake systems in 62 fungal species for which the complete genome sequences are available. This inventory reveals that three types of K(+) uptake systems, TRK and HAK transporters and ACU ATPases, are widely present in several combinations across fungal species. PAT ATPases are less frequently present and are exceptional in Ascomycota. The genome of Magnaporthe oryzae contains four TRK, one HAK, and two ACU genes. The study of the expression of these genes at high K(+), K(+) starvation, and in infected rice leaves revealed that the expression of four genes, ACU1, ACU2, HAK1, and TRK1 is much lower than that of TRK2, TRK3, and TRK4, except under K(+) starvation. The two ACU ATPases were cloned and functionally identified as high-affinity K(+) or Na(+) uptake systems. These two ATPases endow Saccharomyces cerevisiae with the capacity to grow for several generations in low Na(+) concentrations when K(+) was absent, which produces a dramatic increase of cellular Na(+)/K(+) ratio.
Ann file
T1 Species 75 93 Magnaporthe oryzae
N1 Reference T1 Taxonomy:318829
T2 Species 499 517 Magnaporthe oryzae
N2 Reference T2 Taxonomy:318829
T3 Species 655 659 rice
N3 Reference T3 Taxonomy:4530
T4 Species 948 972 Saccharomyces cerevisiae
N4 Reference T4 Taxonomy:4932