Tamai Y, Toh-e A, Oshima Y
J Bacteriol. 1985 Nov;164(2):964-8. doi: 10.1128/jb.164.2.964-968.1985.
A kinetic study of Pi transport with 32Pi revealed that Saccharomyces cerevisiae has two systems of Pi transport, one with a low Km value (8.2 microM) for external Pi and the other with a high Km value (770 microM). The low-Km system was derepressed by Pi starvation, and the activity was expressed under the control of a genetic system which regulates the repressible acid and alkaline phosphatases. The function of the PHO2 gene, which is essential for the derepression of repressible acid phosphatase but not for the derepression of repressible alkaline phosphatase, was also indispensable for the derepression of the low-Km system.
用³²P对磷酸转运进行的动力学研究表明,酿酒酵母有两个磷酸转运系统,一个对胞外磷酸的Km值较低(8.2微摩尔),另一个对胞外磷酸的Km值较高(770微摩尔)。低Km系统在磷酸盐饥饿时被去阻遏,其活性在一个调控可阻遏酸性和碱性磷酸酶的遗传系统控制下表达。PHO2基因的功能对于可阻遏酸性磷酸酶的去阻遏必不可少,但对于可阻遏碱性磷酸酶的去阻遏并非必需,它对于低Km系统的去阻遏同样不可或缺。