Calero Fernando, Montiel Vera, Caracuel Zaira, Cabello-Hurtado Francisco, Ramos José
Departamento de Microbiologiá, Universidad de Córdoba, Campus Universitario de Rabanales Edif. Severo Ochoa, 14071 Córdoba, Spain.
FEMS Yeast Res. 2004 Mar;4(6):619-24. doi: 10.1016/j.femsyr.2003.11.003.
Trk1 and Trk2 are the major K(+) transport systems in Schizosaccharomyces pombe. Both transporters individually seem to be able to cope with K(+) requirements of the cells under normal conditions, since only the double mutant shows defective K(+) transport and defective growth at limiting K(+) concentrations. We have studied in detail the role of SpTrk1 and SpTrk2 under different ion stress conditions. Results show that the strain with only Trk1 (trk1(+)) is less sensitive to Li(+) and to hygromycin B, it grows better at low K(+) and it survives longer in a medium without K(+) than the strain expressing only Trk2 (trk2(+)). We conclude that Trk1 contributes more efficiently than Trk2 to the performance of the fission yeast under ion stress conditions. In the wild type both trk1(+) and trk2(+) genes are expressed and probably collaborate for the performance of the cells.
Trk1和Trk2是粟酒裂殖酵母中主要的钾离子转运系统。在正常条件下，这两种转运蛋白各自似乎都能够满足细胞对钾离子的需求，因为只有双突变体在钾离子浓度受限的情况下表现出钾离子转运缺陷和生长缺陷。我们已经详细研究了SpTrk1和SpTrk2在不同离子胁迫条件下的作用。结果表明，仅含有Trk1的菌株（trk1(+)）对锂离子和潮霉素B的敏感性较低，在低钾条件下生长得更好，并且在无钾培养基中的存活时间比仅表达Trk2的菌株（trk2(+)）更长。我们得出结论，在离子胁迫条件下，Trk1比Trk2更有效地促进裂殖酵母的性能。在野生型中，trk1(+)和trk2(+)基因均表达，并且可能共同作用以维持细胞的性能。
