Exosomes (secreted extracellular vesicles formed in the intracellular vesicular transport system) play a crucial role in distant cell–cell communication. Exosomes transfer active forms of various biomolecules; the molecular composition of the exosomal cargo is a result of targeted selection and depends on the type of producer cells. The mechanisms underlying exosome formation and cargo selection are poorly understood. It is believed that there are several pathways for exosome biogenesis, although the questions about their independence and simultaneous coexistence in the cell still remain open. The least studied topic is the recently discovered mechanism of exosome formation associated with lipid rafts, or membrane lipid microdomains. Here, we present modern concepts and basic hypotheses on the mechanisms of exosome biogenesis and secretion and summarize current data on the involvement of lipid rafts and their constituent molecules in these processes. Special attention is paid to the analysis of possible role in the exosome formation of raft-forming proteins of the SPFH family, components of planar rafts, and caveolin, the main component of caveolae.

中文翻译：

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外泌体生物发生中的脂筏

外泌体（在细胞内囊泡运输系统中形成的分泌性细胞外囊泡）在远距离细胞间通讯中起着至关重要的作用。外泌体转移各种生物分子的活性形式；外泌体货物的分子组成是靶向选择的结果，取决于生产细胞的类型。外泌体形成和货物选择的潜在机制知之甚少。人们认为外泌体生物发生有多种途径，尽管关于它们在细胞中的独立性和同时共存的问题仍然悬而未决。研究最少的主题是最近发现的与脂筏或膜脂微区相关的外泌体形成机制。这里，我们提出了关于外泌体生物发生和分泌机制的现代概念和基本假设，并总结了有关脂筏及其组成分子参与这些过程的当前数据。特别注意分析在外泌体形成中可能的作用 SPFH 家族的筏形成蛋白、平面筏的组成部分和小窝（小窝的主要成分）。