Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France; GSK, Siena, Italy.
Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.
J Proteomics. 2021 Feb 10;232:104025. doi: 10.1016/j.jprot.2020.104025. Epub 2020 Nov 4.
Among diarrheagenic E. coli (DEC), enterohaemorrhagic E. coli (EHEC) are the most virulent anthropozoonotic agents. The ability of bacterial cells to functionally interact with their surrounding essentially relies on the secretion of different protein effectors. To experimentally determine the repertoire of extracytoproteins in E. coli O157:H7, a subproteomic analysis was performed not only considering the extracellular milieu but the cell surface and outer membrane vesicles. Following a secretome-based approach, the proteins trafficking from the interior to the exterior of the cell were depicted considering cognate protein transport systems and subcellular localisation. Label-free quantitative analysis of the proteosurfaceome, proteovesiculome and exoproteome from E. coli O157:H7 grown in three different nutrient media revealed differential protein expression profiles and allowed defining the core and variant subproteomes. Network analysis further revealed the higher abundance of some protein clusters in chemically defined medium over rich complex medium, especially related to some outer membrane proteins, ABC transport and Type III secretion systems. This first comprehensive study of the EHEC secretome unravels the profound influence of environmental conditions on the extracytoplasmic proteome, provides new insight in the physiology of E. coli O157:H7 and identifies potentially important molecular targets for the development of preventive strategies against EHEC/STEC. SIGNIFICANCE: Escherichia coli O157:H7 is responsible for severe diarrhoea especially in young children. Despite years of investigations, the global view of the extracytoplasmic proteins expressed in this microorganism was eluded. To provide the first comprehensive view of the secretome landscape of E. coli O157:H7, the exoproteome, proteosurfaceome and proteovesiculome were profiled using growth conditions most likely to induce changes in bacterial protein secretion. The profound influence of growth conditions on the extracytoplasmic proteome was unravelled and allowed identifying the core and variant subproteomes. Besides new insight in the physiology of enterohaemorrhagic E. coli, these proteins potentially constitute important molecular targets for the development of preventive strategies.
在致泻性大肠杆菌（DEC）中，肠出血性大肠杆菌（EHEC）是最具毒力的人兽共患病原体。细菌细胞与周围环境进行功能相互作用的能力主要依赖于不同蛋白质效应子的分泌。为了实验确定大肠杆菌 O157:H7 中的细胞外蛋白组，不仅考虑细胞外环境，还考虑细胞表面和外膜囊泡，进行了亚蛋白组分析。基于分泌组的方法，根据同源蛋白转运系统和亚细胞定位描绘了从细胞内部运输到细胞外部的蛋白质。使用无标记定量分析方法，分析了在三种不同营养培养基中生长的大肠杆菌 O157:H7 的蛋白质质表面组、蛋白质囊泡组和细胞外蛋白组，揭示了不同的蛋白质表达谱，并定义了核心和变体亚蛋白组。网络分析进一步表明，在化学成分确定的培养基中，某些蛋白质簇的丰度高于丰富的复杂培养基，尤其是与某些外膜蛋白、ABC 转运和 III 型分泌系统有关。这项对 EHEC 分泌组的首次全面研究揭示了环境条件对细胞外蛋白质组的深远影响，为大肠杆菌 O157:H7 的生理学提供了新的见解，并确定了针对 EHEC/STEC 开发预防策略的潜在重要分子靶标。意义：大肠杆菌 O157:H7 是导致尤其是幼儿严重腹泻的原因。尽管经过多年的研究，该微生物中外泌蛋白质的全局视图仍未被揭示。为了提供大肠杆菌 O157:H7 分泌组全景的首次全面视图，使用最有可能诱导细菌蛋白质分泌变化的生长条件来分析细胞外蛋白质组、质表面组和蛋白质囊泡组。揭示了生长条件对细胞外蛋白质组的深远影响，并允许鉴定核心和变体亚蛋白组。除了对肠出血性大肠杆菌生理学的新见解外，这些蛋白质可能构成预防策略开发的重要分子靶标。
