Experimental Systems Immunology Laboratory, Max Planck Institute of Biochemistry, Martinsried, Germany; Institute of Innate Immunity, Department of Systems Immunology and Proteomics, Medical Faculty, University of Bonn, Bonn, Germany.
Experimental Systems Immunology Laboratory, Max Planck Institute of Biochemistry, Martinsried, Germany.
Cell Rep. 2021 Mar 9;34(10):108826. doi: 10.1016/j.celrep.2021.108826.
A major pathway for proinflammatory protein release by macrophages is inflammasome-mediated pyroptotic cell death. As conventional secretion, unconventional secretion, and cell death are executed simultaneously, however, the cellular mechanisms regulating this complex paracrine program remain incompletely understood. Here, we devise a quantitative proteomics strategy to define the cellular exit route for each protein by pharmacological and genetic dissection of cellular checkpoints regulating protein release. We report the release of hundreds of proteins during pyroptosis, predominantly due to cell lysis. They comprise constitutively expressed and transcriptionally induced proteins derived from the cytoplasm and specific intracellular organelles. Many low-molecular-weight proteins including the cytokine interleukin-1β, alarmins, and lysosomal-cargo proteins exit cells in the absence of cell lysis. Cytokines and alarmins are released in an endoplasmic reticulum (ER)-Golgi-dependent manner as free proteins rather than by extracellular vesicles. Our work provides an experimental framework for the dissection of cellular exit pathways and a resource for pyroptotic protein release.
巨噬细胞中促炎蛋白释放的主要途径是炎性小体介导热激细胞死亡。然而，由于常规分泌、非常规分泌和细胞死亡同时进行，因此，调节这种复杂旁分泌程序的细胞机制仍不完全清楚。在这里，我们设计了一种定量蛋白质组学策略，通过对调节蛋白释放的细胞检查点进行药理学和遗传学剖析，来确定每种蛋白质的细胞外排途径。我们报告了在细胞焦亡过程中释放了数百种蛋白质，主要是由于细胞裂解。它们包括来自细胞质和特定细胞内细胞器的组成型表达和转录诱导的蛋白质。许多低分子量蛋白质，包括细胞因子白细胞介素-1β、警报素和溶酶体货物蛋白，在没有细胞裂解的情况下离开细胞。细胞因子和警报素以依赖内质网（ER）-高尔基体的方式作为游离蛋白释放，而不是通过细胞外囊泡释放。我们的工作为细胞外排途径的剖析提供了一个实验框架，并为细胞焦亡蛋白释放提供了一个资源。
