McKie A T, Barrow D, Latunde-Dada G O, Rolfs A, Sager G, Mudaly E, Mudaly M, Richardson C, Barlow D, Bomford A, Peters T J, Raja K B, Shirali S, Hediger M A, Farzaneh F, Simpson R J
Department of Molecular Medicine, Guy's, King's and St. Thomas' School of Medicine, King's College London, Rayne Institute, Denmark Hill Campus, 123 Coldharbour Lane, London SE5 9NU, UK.
Science. 2001 Mar 2;291(5509):1755-9. doi: 10.1126/science.1057206. Epub 2001 Feb 1.
The ability of intestinal mucosa to absorb dietary ferric iron is attributed to the presence of a brush-border membrane reductase activity that displays adaptive responses to iron status. We have isolated a complementary DNA, Dcytb (for duodenal cytochrome b), which encoded a putative plasma membrane di-heme protein in mouse duodenal mucosa. Dcytb shared between 45 and 50% similarity to the cytochrome b561 family of plasma membrane reductases, was highly expressed in the brush-border membrane of duodenal enterocytes, and induced ferric reductase activity when expressed in Xenopus oocytes and cultured cells. Duodenal expression levels of Dcytb messenger RNA and protein were regulated by changes in physiological modulators of iron absorption. Thus, Dcytb provides an important element in the iron absorption pathway.
肠黏膜吸收膳食三价铁的能力归因于存在一种刷状缘膜还原酶活性，该活性对铁状态表现出适应性反应。我们分离出了一个互补DNA，即Dcytb（十二指肠细胞色素b），它在小鼠十二指肠黏膜中编码一种假定的质膜双血红素蛋白。Dcytb与质膜还原酶细胞色素b561家族有45%至50%的相似性，在十二指肠肠上皮细胞的刷状缘膜中高度表达，并且在非洲爪蟾卵母细胞和培养细胞中表达时可诱导三价铁还原酶活性。Dcytb信使核糖核酸和蛋白质的十二指肠表达水平受铁吸收生理调节因子变化的调控。因此，Dcytb是铁吸收途径中的一个重要元素。
