Cloning and functional characterization of the Anopheles albimanus DMT1/NRAMP homolog:: Implications in iron metabolism in mosquitoes
Cloning and functional characterization of the Anopheles albimanus DMT1/NRAMP homolog:: Implications in iron metabolism in mosquitoes
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DOI：
10.1016/j.ibmb.2007.02.009
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发表时间：
2007-06-01
影响因子：
3.8
通讯作者：
Lanz-Mendoza, Humberto
中科院分区：
文献类型：
--
作者：
Martinez-Barnetche, Jesus;Garcia Solache, Monica;Lanz-Mendoza, Humberto
除了在新陈代谢中发挥广泛作用外，铁在昆虫体内还与卵黄形成和免疫反应有关。NRAMP家族包括后生动物中一个保守的二价阳离子转运蛋白家族。为了深入了解NRAMP在白斑按蚊中的作用，我们克隆了一个编码571个残基蛋白（AnaNRAMP）的cDNA，该蛋白具有定义NRAMP家族的结构特征。AnaNRAMP mRNA注入爪蟾卵母细胞后诱导Fe-59（2+）结合。Western blot分析显示，AnaNRAMP在未喂食雌蚊的头部、中肠和马尔比氏小管中高水平表达。在供血时，AnaNRAMP水平在中肠降低，而在马尔比氏小管中升高。通过透射电镜免疫定位，AnaNRAMP定位于马尔比氏小管主细胞的细胞内结缔组织或球体的膜上。综上所述，我们的研究结果表明AnaNRAMP在铁运输中起重要作用，并表明蚊子马尔比氏小管是铁稳态的重要器官。(c) 2007 Elsevier Ltd.版权所有。
In addition to its wide role in metabolism, iron in insects has been implicated in vitellogenesis and the immune response. The NRAMP family comprises a well-conserved family of divalent cation transporters in metazoans. To gain insight on the role of NRAMP in Anopheles albimanus, we cloned a cDNA encoding a 571-residue protein (AnaNRAMP) with the structural features defining the NRAMP family. AnaNRAMP mRNA induced Fe-59(2+) incorporation when injected into Xenopus oocytes. Western blot analysis revealed that AnaNRAMP is expressed in the head, midgut and at high levels in Malpighian tubules of unfed female mosquito. Upon blood feeding, AnaNRAMP levels were reduced in the midgut whereas they increased in the Malpighian tubules. Using immunolocalization by transmission electron microscopy, AnaNRAMP was localized in the membrane of the intra-cellular concretions or spherites of the Malpighian tubule principal cells. Taken together, our results suggest an important role of AnaNRAMP in iron transport and indicate a role of the mosquito Malpighian tubule as an important organ for iron homeostasis. (c) 2007 Elsevier Ltd. All rights reserved.