Mitochondria vary in morphology and function in different tissues; however, little is known about their molecular diversity among cell types. Here we engineered MitoTag mice, which express a Cre recombinase-dependent green fluorescent protein targeted to the outer mitochondrial membrane, and developed an isolation approach to profile tagged mitochondria from defined cell types. We determined the mitochondrial proteome of the three major cerebellar cell types (Purkinje cells, granule cells and astrocytes) and identified hundreds of mitochondrial proteins that are differentially regulated. Thus, we provide markers of cell-type-specific mitochondria for the healthy and diseased mouse and human central nervous systems, including in amyotrophic lateral sclerosis and Alzheimer's disease. Based on proteomic predictions, we demonstrate that astrocytic mitochondria metabolize long-chain fatty acids more efficiently than neuronal mitochondria. We also characterize cell-type differences in mitochondrial calcium buffering via the mitochondrial calcium uniporter (Mcu) and identify regulator of microtubule dynamics protein 3 (Rmdn3) as a determinant of endoplasmic reticulum-mitochondria proximity in Purkinje cells. Our approach enables exploring mitochondrial diversity in many in vivo contexts.

中文翻译：

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脑线粒体的细胞类型特异性分析揭示了功能和分子多样性。

线粒体在不同组织中的形态和功能各不相同；然而，关于它们在细胞类型之间的分子多样性知之甚少。在这里，我们设计了MitoTag小鼠，该小鼠表达靶向线粒体外膜的Cre重组酶依赖性绿色荧光蛋白，并开发了一种从定义的细胞类型中分析标记的线粒体的分离方法。我们确定了三种主要小脑细胞类型（Purkinje细胞，颗粒细胞和星形胶质细胞）的线粒体蛋白质组，并鉴定了数百种差异调节的线粒体蛋白质。因此，我们为健康和患病的小鼠和人类中枢神经系统（包括肌萎缩性侧索硬化症和阿尔茨海默氏病）提供了细胞类型特异性线粒体的标记。根据蛋白质组学预测，我们证明星形细胞线粒体比神经元线粒体更有效地代谢长链脂肪酸。我们还通过线粒体钙单向转运蛋白（Mcu）表征线粒体钙缓冲中的细胞类型差异，并确定微管动力学蛋白3（Rmdn3）的调节剂作为Purkinje细胞内质网-线粒体接近性的决定因素。我们的方法能够在许多体内环境中探索线粒体多样性。