Iron in Mitochondrial Physiology and Disease

描述（由申请人提供）：细胞铁代谢的重要部分发生在线粒体中，包括铁输入、铁-硫簇组装和血红素生物合成。一些血红素和铁硫簇被安装到呼吸复合物中，而另一些则被输出到细胞溶质和其他细胞隔室。整个系统受到严格监管。在本项目中，将从系统生物学的角度研究线粒体中的铁组分和铁相关过程，以获得健康和疾病状态代谢的新见解。从酵母和人细胞中分离和完整的线粒体将进行穆斯堡尔谱、电子顺磁共振、电子吸收光谱和电感耦合等离子体发射质谱，以评估细胞器的“铁组”。这种生物物理方法将用于研究从不同条件下生长的野生型酵母细胞（发酵与呼吸;铁缺乏与铁充足）和不同遗传菌株中分离的线粒体。已知待研究的酵母菌株（Yah 1 p、Atm 1 p、Mrs 3 p/4p和Mtm 1 p缺失）通常通过引起铁在线粒体中积累来影响铁代谢。在人类中也有类似的情况，其中同源蛋白质的缺陷导致铁的积累。积累的铁将被表征并研究其反应性。用于在线粒体中“运输”铁的低分子量单核非血红素复合物将通过色谱法分离，然后通过质谱法和NMR光谱法鉴定。这些配合物的代谢功能也将进行研究。将来自人HL 60细胞的线粒体的铁组与酵母线粒体的铁组进行比较，并且将从铁线粒体生物化学和生理学方面解释差异。该项目意义重大，因为将探索线粒体中疾病相关的铁积累机制，并分离和鉴定用于细胞运输的铁复合物。这样的知识可以更好地控制铁贩运进出细胞器。这些铁络合物也可能在产生活性氧（ROS）中发挥作用，活性氧被认为是细胞损伤和衰老的某些方面的原因。

DESCRIPTION (provided by applicant): A significant portion of cellular iron metabolism occurs in the mitochondria, including iron import, iron-sulfur cluster assembly and heme biosynthesis. Some heme and iron-sulfur clusters are installed into respiratory complexes, while others are exported to the cytosol and other cellular compartments. The entire system is tightly regulated. In this project, iron components and iron-related processes in mitochondria will be investigated from a systems-biology perspective to gain new insights into the metabolism of healthy and diseased states. Isolated and intact mitochondria from yeast and human cells will be subjected to M"ssbauer spectroscopy, electron paramagnetic resonance, electronic absorption spectroscopy and inductively coupled plasma emission mass spectrometry to evaluate the "iron-ome" of the organelle. This biophysical approach will be used to study mitochondria isolated from wild-type yeast cells grown under different conditions (fermenting vs. respiring; Fe deficient vs. Fe replete) and from different genetic strains. The yeast strains to be investigated (depleted in Yah1p, Atm1p, Mrs3p/4p, and Mtm1p) are known to affect iron metabolism, generally by causing iron to accumulate in the mitochondria. There are analogous situations in humans, in which defects in homologous proteins result in iron accumulation. The accumulated iron will be characterized and its reactivity investigated. Low molecular weight mononuclear nonheme complexes that are used in "trafficking" iron in the mitochondria will be isolated by chromatography, and then identified by mass spectrometry and NMR spectroscopy. The metabolic function of these complexes will also be investigated. The iron-ome of mitochondria from human HL60 cells will be compared to that of yeast mitochondria and differences will be interpreted in terms of iron mitochondrial biochemistry and physiology. The project is significant because the mechanism of disease-related Fe accumulation in mitochondria will be explored and iron complexes that are used in cellular trafficking will be isolated and identified. Such knowledge may allow better control of iron trafficking into and out of the organelle. These iron complexes may also play a role in generating reactive oxygen species (ROS) which are thought to be responsible for some aspects of cellular damage and aging.