Synapses are the regions of the neuron that enable the transmission and propagation of action potentials on the cost of high energy consumption and elevated demand for mitochondrial ATP production. The rapid changes in local energetic requirements at dendritic spines imply the role of mitochondria in the maintenance of their homeostasis. Using global proteomic analysis supported with complementary experimental approaches, we show that an essential pool of mitochondrial proteins is locally produced at the synapse indicating that mitochondrial protein biogenesis takes place locally to maintain functional mitochondria in axons and dendrites. Furthermore, we show that stimulation of synaptoneurosomes induces the local synthesis of mitochondrial proteins that are transported to the mitochondria and incorporated into the protein supercomplexes of the respiratory chain. Importantly, in a mouse model of fragile X syndrome, Fmr1 KO mice, a common disease associated with dysregulation of synaptic protein synthesis, we observed altered morphology and respiration rates of synaptic mitochondria. That indicates that the local production of mitochondrial proteins plays an essential role in synaptic functions.

中文翻译：

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突触中线粒体蛋白的生物合成由局部翻译支持。

突触是神经元中能够传递和传播动作电位的区域，但代价是高能量消耗和对线粒体 ATP 生产的需求增加。树突棘局部能量需求的快速变化意味着线粒体在维持其稳态中的作用。使用补充实验方法支持的全局蛋白质组分析，我们表明，突触局部产生了重要的线粒体蛋白库，这表明线粒体蛋白生物发生发生在局部，以维持轴突和树突中的功能性线粒体。此外，我们发现，刺激突触神经小体会诱导线粒体蛋白的局部合成，这些蛋白被转运到线粒体并掺入呼吸链的蛋白超复合物中。重要的是，在脆性 X 综合征小鼠模型（Fmr1 KO 小鼠）（一种与突触蛋白合成失调相关的常见疾病）中，我们观察到突触线粒体的形态和呼吸速率发生改变。这表明线粒体蛋白的局部产生在突触功能中发挥着重要作用。