MITOCHONDRIAL IRON STORAGE

线粒体铁储存

• 批准号: 7370500
• 负责人: HELEN NICHOL
• 金额: $ 0.41万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7370500
• 关键词: MITOCHONDRIAL; IRON; STORAGE

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Metals can accumulate in cellular compartments during the normal aging process, through excessive dietary or environmental exposure and from genetic errors in proteins that regulate metal flux within cells. Mitochondrial iron overload is a common feature of several neurological and metabolic diseases. We have shown that in yeast with various errors in iron-sulfur cluster biosynthesis, the form of iron that accumulates differs. In particular, ferrihydrite of the type sequestered by frataxin in vitro is found only in yeast that express frataxin. We now propose to expand this work to compare mitochondrial iron in two human diseases, Friedreich's ataxia (FRDA) and sideroblastic anemia (SA) and to begin to address the chemistry of treatment strategies. The following questions will be addressed using XAS 1. How does frataxin's ferroxidase activity contribute to iron core assembly? Iron K-edge spectra will be collected for XANES and EXAFS analysis of iron cores assembled after amino acid substitutions to frataxin's ferroxidation site. 2. Does frataxin assemble an iron core in vivo that is structurally similar to that assembled in vivo? Frataxin assembled in vivo will be separated on a non-denaturing gel and K-edge spectra collected in situ. 3. Is mitochondrial iron that accumulates in yeast FRDA models and human FRDA the same? Mitochondria will be isolated from FRDA fibroblast cultures and K-edge spectra collected for XANES analysis. 4. Can selenium form a complex with iron in frataxin deficient mitochondria? Mitochondria will be isolated from frataxin-deficient yeast grown on selenium-supplemented media and spectra collected at the iron and selenium K-edges for EXAFS analysis. 5. Do iron deposits differ between SA and FRDA? Mitochondria will be isolated from an SA model and iron K-edge spectra collected for XANES analysis. This work will contribute to the development of better treatment strategies for these mitochondrial iron overload disorders.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。在正常的衰老过程中，通过过度的饮食或环境暴露以及调节细胞内金属通量的蛋白质中的遗传错误，金属可以在细胞隔室中积累。线粒体铁超载是几种神经和代谢疾病的共同特征。我们已经表明，在铁硫簇生物合成中具有各种错误的酵母中，积累的铁的形式不同。特别地，在体外被共济蛋白螯合的类型的水铁矿仅在表达共济蛋白的酵母中发现。我们现在建议扩展这项工作，以比较两种人类疾病（弗里德赖希共济失调（FRDA）和铁粒幼细胞贫血（SA））中的线粒体铁，并开始解决治疗策略的化学问题。以下问题将使用XAS 1解决。frataxin的铁氧化酶活性如何促进铁核心组装？将收集铁K边光谱，用于在氨基酸取代至frataxin的铁氧化位点后组装的铁核心的XANES和EXAFS分析。2. Frataxin在体内组装的铁芯是否与体内组装的铁芯结构相似？将在非变性凝胶上分离体内组装的Frataxin，并原位收集K边光谱。3.在酵母FRDA模型和人类FRDA中积累的线粒体铁是相同的吗？将从FRDA成纤维细胞培养物中分离线粒体，并收集K边光谱用于XANES分析。4.硒能在共济失调蛋白缺乏的线粒体中与铁形成复合物吗？将从在补硒培养基上生长的缺乏共济失调蛋白的酵母中分离线粒体，并在铁和硒K边缘收集光谱用于EXAFS分析。5. SA和FRDA之间的铁矿床是否不同？将从SA模型中分离线粒体，并收集铁K边缘光谱用于XANES分析。这项工作将有助于为这些线粒体铁超载疾病制定更好的治疗策略。