Large volumes of liquid and other materials from the extracellular environment are internalised by eukaryotic cells via an endocytic process called macropinocytosis. It is now recognised that this fundamental and evolutionarily conserved pathway is hijacked by numerous intracellular pathogens as an entry portal to the host cell interior. Yet, an increasing number of additional cellular functions of macropinosomes in pathologic processes have been reported beyond this role for fluid internalisation. It emerges that the identity of macropinosomes can vary hugely and change rapidly during their lifetime. A deeper understanding of this important multi-faceted compartment is based on novel methods for their investigation. These methods are either imaging-based for the tracking of macropinosome dynamics, or they provide the means to extract macropinosomes at high purity for comprehensive proteomic analyses. Here, we portray these new approaches for the investigation of macropinosomes. We document how these method developments have provided insights for a new understanding of the intracellular lifestyle of the bacterial pathogens Shigella and Salmonella. We suggest that a systematic complete characterisation of macropinosome subversion with these approaches during other infection processes and pathologies will be highly beneficial for our understanding of the underlying cellular and molecular processes.

中文翻译：

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在宿主-病原体串扰期间解密新出现的巨蛋白体功能的新方法

来自细胞外环境的大量液体和其他物质通过称为巨胞饮作用的内吞过程被真核细胞内化。现在认识到，这种基本的和进化上保守的途径被许多细胞内病原体劫持，作为宿主细胞内部的入口。然而，除了液体内化的这一作用之外，已经报道了越来越多的大蛋白体在病理过程中的额外细胞功能。研究表明，巨松质体的身份在它们的一生中变化很大并且变化很快。对这个重要的多面隔间的更深入理解是基于他们调查的新方法。这些方法要么是基于成像的，用于跟踪巨松质体动力学，或者它们提供了以高纯度提取巨蛋白体以进行全面蛋白质组学分析的方法。在这里，我们描绘了这些用于研究巨松质体的新方法。我们记录了这些方法的发展如何为重新理解细菌病原体的细胞内生活方式提供了见解志贺氏菌和沙门氏菌。我们建议在其他感染过程和病理过程中使用这些方法对巨松质体颠覆进行系统的完整表征，这对我们理解潜在的细胞和分子过程非常有益。