Klausner R D, Dancis A
Cell Biology and Metabolism Branch, NICHD, NIH, Bethesda, MD 20892.
FEBS Lett. 1994 Nov 28;355(2):109-13. doi: 10.1016/0014-5793(94)01111-7.
Studies of mutants of the yeast Saccharomyces cerevisiae have led to the identification of genes required for high affinity iron uptake. Reduction of iron (III) outside the cell is accomplished by means of reductases encoded by FRE1 and FRE2, homologues of the gp91-phox component of the oxygen reductase of human granulocytes. High affinity iron (II) transport from the exterior to the interior of the cell occurs by means of a transport system that has not been molecularly characterized. However, the transport process requires the activity of a copper-containing oxidase encoded by FET3. The amino acid sequence of this protein resembles other multi-copper oxidases, including mammalian ceruloplasmin. High affinity copper uptake mediated by the copper transport protein encoded by CTR1 is required to provide the FET3 protein with copper, and thus copper uptake is indirectly required for ferrous iron uptake. These genetic elements of yeast and their relationships may be conserved in complex eukaryotic organisms.
对酿酒酵母突变体的研究已导致鉴定出高亲和力铁摄取所需的基因。细胞外铁（III）的还原是通过由FRE1和FRE2编码的还原酶完成的，FRE1和FRE2是人类粒细胞氧还原酶的gp91-phox成分的同源物。细胞外高亲和力铁（II）从细胞外转运到细胞内是通过一个尚未进行分子特征描述的转运系统实现的。然而，转运过程需要由FET3编码的含铜氧化酶的活性。该蛋白质的氨基酸序列类似于其他多铜氧化酶，包括哺乳动物的铜蓝蛋白。由CTR1编码的铜转运蛋白介导的高亲和力铜摄取是为FET3蛋白提供铜所必需的，因此亚铁摄取间接需要铜摄取。酵母的这些遗传元件及其关系可能在复杂的真核生物中保守。
