Vesicular transport between different membrane compartments is a key process in cell biology required for the exchange of material and information. The complex machinery that executes the formation and delivery of transport vesicles has been intensively studied and yielded a comprehensive view of the molecular principles that underlie the budding and fusion process. Tethering also represents an essential step in each trafficking pathway. It is mediated by Rab GTPases in concert with so-called tethering factors, which constitute a structurally diverse family of proteins that share a similar role in promoting vesicular transport. By simultaneously binding to proteins and/or lipids on incoming vesicles and the target compartment, tethers are thought to bridge donor and acceptor membrane. They thus provide specificity while also promoting fusion. However, how tethering works at a mechanistic level is still elusive. We here discuss the recent advances in the structural and biochemical characterization of tethering complexes that provide novel insight on how these factors might contribute the efficiency of fusion.

中文翻译：

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膜系链的结构及其在融合中的作用。

不同膜区室之间的囊泡运输是细胞生物学中交换材料和信息所需的关键过程。已经深入研究了执行运输小泡的形成和传递的复杂机制，并全面了解了萌芽和融合过程的分子原理。系留也是每个贩运途径中必不可少的步骤。它是由Rab GTPases与所谓的束缚因子介导的，后者构成了结构上多样的蛋白质家族，在促进水泡运输方面起着相似的作用。通过同时与进入的囊泡和靶标区室上的蛋白质和/或脂质结合，系链被认为桥接了供体和受体膜。因此，它们在提供特异性的同时还促进了融合。但是，如何在机制级别上进行网络绑定仍然难以捉摸。我们在这里讨论了束缚复合物的结构和生物化学表征的最新进展，这些进展为这些因素如何促进融合效率提供了新的见解。