FERRIC IRON REDUCTION AND IRON ASSIMILATION IN SACCHAROMYCES-CEREVISIAE
FERRIC IRON REDUCTION AND IRON ASSIMILATION IN SACCHAROMYCES-CEREVISIAE
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DOI：
10.1016/0162-0134(92)84070-4
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发表时间：
1992-08-15
影响因子：
3.9
通讯作者：
KLAUSNER, RD
中科院分区：
文献类型：
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作者：
ANDERSON, GJ;LESUISSE, E;KLAUSNER, RD
我们以酿酒酵母为模式生物，研究了铁还原在真核铁吸收中的作用。酿酒酵母能够利用螯合铁作为铁源，将铁还原为亚铁形式，然后被细胞内化。已鉴定出一个基因(FRE1)，该基因编码铁还原和有效铁同化所需的蛋白质，从而将这两种活性联系在一起。预测的FRE1蛋白似乎是一种膜蛋白，并与人类呼吸爆发氧化酶的β亚基同源。这些数据表明，FRE1是铁还原酶的一个结构成分。亚细胞分级研究表明，分离的质膜中铁还原酶的活性不能反映完整细胞的活性，这意味着细胞完整性是主要的酿酒酵母铁还原酶功能所必需的。从质膜中部分纯化了依赖NADPH的质膜铁还原酶。初步证据表明，细胞表面铁还原酶除了介导细胞铁摄取外，还可能有助于调节酵母细胞的细胞内氧化还原潜力。
We have used the yeast Saccharomyces cerevisiae as a model organism to study the role of ferric iron reduction in eucaryotic iron uptake. S. cerevisiae is able to utilize ferric chelates as an iron source by reducing the ferric iron to the ferrous form, which is subsequently internalized by the cells. A gene (FRE1) was identified which encodes a protein required for both ferric iron reduction and efficient ferric iron assimilation, thus linking these two activities. The predicted FRE1 protein appears to be a membrane protein and shows homology to the beta-subunit of the human respiratory burst oxidase. These data suggest that FRE1 is a structural component of the ferric reductase. Subcellular fractionation studies showed that the ferric reductase activity of isolated plasma membranes did not reflect the activity of the intact cells, implying that cellular integrity was necessary for function of the major S. cerevisiae ferric reductase. An NADPH-dependent plasma membrane ferric reductase was partially purified from plasma membranes. Preliminary evidence suggests that the cell surface ferric reductase may, in addition to mediating cellular iron uptake, help modulate the intracellular redox potential of the yeast cell.