REGULATION OF NRAMP1 MEDIATED IRON TRANSPORT

NRAMP1 介导的铁转运的调节

• 批准号: 6087965
• 负责人: BRUCE S ZWILLING
• 金额: $ 26.97万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6087965
• 关键词: cytokine; genetic regulation; genetic susceptibility; glycosylation; ion transport; iron metabolism; macrophage; membrane proteins; molecular site; phosphorylation; posttranslational modifications; protein kinase C; protein structure function; radiotracer; site directed mutagenesis; tissue /cell culture; transfection

DESCRIPTION (adapted from the application) Macrophages are central to maintenance of iron homeostasis, acting as a major iron storage site in the body (1-3). Iron is also a major factor in macrophage anti-microbial defense, acting as a catalyst in the generation of reactive hydroxyl radicals (4-6). The Nramp1 gene in mice (9-11) controls natural resistance to infection by a number of intracellular pathogens. The gene exists as two allelic forms that determine resistance or susceptibility to growth of these pathogens within macrophages during the early stages of infection. The protein is expressed in endocytic vesicles of macrophages that traffic to the phagosome. The susceptible allele differs from the resistant allele by a single glycine to aspartic acid substitution in the fourth transmembrane domain. Our laboratory has investigated the role of Nramp1 in macrophage antimicrobial activity and in iron metabolism. We have shown that Nramp1 transports iron into phagosomes where the iron serves to catalyze the Haber-Weiss reaction. The resulting production of reactive hydroxyl radical then inhibits the growth of the phagocytized bacteria. Our observations that Nramp serves as a regulator of antimicrobial activity by transporting iron into phagosomes serves as the basis of this application to determine the factors that regulate Nramp1 mediated iron transport. Our specific aims are: 1. To determine regulation of Nramp1 mediated iron transport; 2. To determine if iron transport by Nramp1 requires protein phosphorylation and 3. To determine, by site directed mutagenesis, the domains within the Nramp1 protein that affect iron transport.

描述（改编自应用程序） 巨噬细胞是维持铁稳态的核心，作为一个主要的 体内铁的储存部位（1 - 3）。铁也是巨噬细胞中的一个主要因素 抗微生物防御，作为一种催化剂，在产生反应， 羟基自由基（4 - 6）。小鼠中的Nramp1基因（9 - 11）控制自然 对许多细胞内病原体感染的抵抗力。基因存在 作为两种等位基因形式，决定了对生长的抗性或易感性， 这些病原体在感染的早期阶段在巨噬细胞内。的 蛋白质在巨噬细胞的内吞囊泡中表达， 吞噬体易感等位基因与耐药等位基因的差异仅为一个 第四跨膜结构域中的甘氨酸取代为天冬氨酸。我们 实验室研究了Nramp1在巨噬细胞抗菌中的作用， 活性和铁代谢。我们已经证明，Nramp1将铁转运到 在吞噬体中，铁用于催化Haber-Weiss反应。的 由此产生的反应性羟基自由基随后抑制了 被吞噬的细菌。我们的观察表明，Nramp作为一个监管机构， 通过将铁转运到吞噬体中的抗微生物活性作为基础 以确定调节Nramp1介导的铁的因子 运输我们的具体目标是：1.为了确定Nramp1介导的 铁运输; 2.为了确定Nramp1的铁转运是否需要蛋白质 磷酸化和3.为了通过定点诱变确定结构域， 影响铁转运的Nramp1蛋白。