Lesuisse E, Casteras-Simon M, Labbe P
Laboratoire de Biochimie des Porphyrines, Institut Jacques-Monod, Université Paris, France.
FEMS Microbiol Lett. 1997 Nov 1;156(1):147-52. doi: 10.1111/j.1574-6968.1997.tb12720.x.
Cytochrome P-450 reductase (encoded by the NCP1 gene) was found to catalyse all the NADPH-dependent ferrireductase activities associated with isolated plasma membranes of the yeast Saccharomyces cerevisiae. We therefore examined the contribution of this enzyme to the ferrireductase activity of cells in vivo. Cytochrome P-450 reductase was shown to be not essential for the cell ferrireductase activity, but it influenced this activity, with different effects on the Fre1- and the Fre2-dependent reductase systems. Overexpression of FRE1 did not lead to an increased ferrireductase activity of the cells when NCP1 was repressed. In contrast, cells that overexpressed FRE2 had maximal ferrireductase activity when NCP1 was repressed. The degree of NCP1 expression also affected the amount of iron and copper accumulated by the cells during growth. The biochemical implications and the physiological significance of these observations are discussed.
细胞色素P-450还原酶（由NCP1基因编码）被发现可催化与酿酒酵母分离的质膜相关的所有依赖于NADPH的铁还原酶活性。因此，我们研究了这种酶在体内对细胞铁还原酶活性的贡献。结果表明，细胞色素P-450还原酶对于细胞铁还原酶活性并非必不可少，但它会影响这种活性，对依赖Fre1和依赖Fre2的还原酶系统有不同影响。当NCP1被抑制时，FRE1的过表达并未导致细胞铁还原酶活性增加。相反，过表达FRE2的细胞在NCP1被抑制时具有最大铁还原酶活性。NCP1的表达程度也影响细胞在生长过程中积累的铁和铜的量。本文讨论了这些观察结果的生化意义和生理重要性。
