Proteome Composition of Lysosomes and Autophagosomes after Proteasome Inhibition

Lysosomes are a major site of intracellular acidic hydrolase-mediated proteolysis and cellular degradation in a membrane-enclosed organelle. Alternatively, soluble, ubiquitin-bound proteins are degraded via the proteasome, a megadalton protein complex within the cytoplasm. The interplay between both degradation pathways has been of increasing interest in recent years. To determine the effects of proteasome inhibition on the lysosomal compartment, we investigated enriched lysosomal fractions, autophagosomal fractions and immunoprecipitated proteasomes from HEK293 cells after proteasome inibition by MG132 or bortezomib in comparison to the respective fractions from control cells.

溶酶体（Lysosomes）作为一种膜包被细胞器，是细胞内酸性水解酶介导的蛋白水解与细胞降解的核心场所。与之相对，可溶性泛素结合蛋白可通过蛋白酶体（proteasome）进行降解——该复合物是细胞质内的兆道尔顿级蛋白复合体。近年来，这两条降解通路之间的相互作用愈发受到学界关注。为明确蛋白酶体抑制对溶酶体区室的影响，我们以经MG132或硼替佐米（bortezomib）处理的HEK293细胞为研究对象，分析其富集得到的溶酶体组分、自噬体组分以及免疫沉淀纯化的蛋白酶体，并与对照组细胞的对应组分进行对照分析。