线粒体一碳代谢适应酵母、植物和哺乳动物的特殊需要

Mitochondrial one-carbon metabolism is adapted to the specific needs of yeast, plants and mammals.

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|核心内容：

在真核生物中，叶酸代谢被划分在细胞质和细胞器之间。

线粒体的叶酸途径被调整为服务于生物体的新陈代谢。

在酵母中，线粒体通过生成甲酸盐来支持胞质嘌呤的合成。

这一途径对于生存是重要的，但不是必需的，这与酵母代谢的灵活性是一致的。

在植物中，线粒体途径通过甘氨酸产生丝氨酸来支持光呼吸。

这条途径在光合作用条件下是必不可少的，酶的表达随着光合作用活性的不同而不同。

在哺乳动物中，线粒体酶在组织和发育过程中的表达是不同的。

在胚胎中，线粒体为嘌呤的合成提供甲酸盐和甘氨酸，这是生存所必需的过程；在成年组织中，通过线粒体的通量有利于丝氨酸的产生。

线粒体叶酸途径的不同取决于物种、组织和发育阶段，深刻地改变了其代谢贡献的性质。

Composite scheme of one-carbon metabolism in plants

Composite scheme of one-carbon folate metabolism in mammals

原文摘要：

In eukaryotes, folate metabolism is compartmentalized between the cytoplasm and organelles. The folate pathways of mitochondria are adapted to serve the metabolism of the organism. In yeast, mitochondria support cytoplasmic purine synthesis through the generation of formate. This pathway is important but not essential for survival, consistent with the flexibility of yeast metabolism. In plants, the mitochondrial pathways support photorespiration by generating serine from glycine. This pathway is essential under photosynthetic conditions and the enzyme expression varies with photosynthetic activity. In mammals, the expression of the mitochondrial enzymes varies in tissues and during development. In embryos, mitochondria supply formate and glycine for purine synthesis, a process essential for survival; in adult tissues, flux through mitochondria can favor serine production. The differences in the folate pathways of mitochondria depending on species, tissues and developmental stages, profoundly alter the nature of their metabolic contribution.

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参考文献：https://sci-hub.ren/10.1002/bies.20420

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