Filamentous morphology in GroE-depleted Escherichia coli induced by impaired folding of FtsE
Filamentous morphology in GroE-depleted Escherichia coli induced by impaired folding of FtsE
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DOI：
10.1128/jb.00493-07
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发表时间：
2007-08-01
影响因子：
3.2
通讯作者：
Taguchi, Hideki
中科院分区：
文献类型：
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作者：
Fujiwara, Kei;Taguchi, Hideki
伴侣蛋白GroE（GroEL和辅伴侣蛋白GroES）是唯一对大肠杆菌的生存力至关重要的伴侣蛋白系统。已知GroE耗尽的细胞表现出丝状形态，表明GroE是参与细胞分裂的蛋白质折叠所必需的。虽然以前的研究，包括蛋白质组范围内的分析GroE基板，提出了几个目标的GroE在细胞分裂，有没有直接的体内证据，以确定哪些基板表现出专性依赖GroE折叠。在候选底物中，我们发现先前过量产生的FtsE（一种参与细胞分裂的蛋白质）完全抑制了GroE缺失的E.杆菌GroE耗竭导致FtsE急剧减少，并且细胞表现出与受损的FtsE功能相关的已知表型。在GroE耗尽的丝状细胞中，FtsA和ZipA的定位是正常的，这两者都在FtsE之前与FtsZ隔环组装，而FtsX，FtsE的相互作用伴侣，和FtsQ，FtsE之后招募，没有定位到环，这表明FtsE的减少是丝状形态的原因。最后，重建的无细胞翻译系统显示，新翻译的FtsE的折叠严格依赖于GroEL/GroES。基于这些发现，我们认为FtsE是大肠杆菌GroE系统的靶底物。coli细胞分裂。
The chaperonin GroE (GroEL and the cochaperonin GroES) is the only chaperone system that is essential for the viability of Escherichia coli. It is known that GroE-depleted cells exhibit a filamentous morphology, suggesting that GroE is required for the folding of proteins involved in cell division. Although previous studies, including proteome-wide analyses of GroE substrates, have suggested several targets of GroE in cell division, there is no direct in vivo evidence to identify which substrates exhibit obligate dependence on GroE for folding. Among the candidate substrates, we found that prior excess production of FtsE, a protein engaged in cell division, completely suppressed the filamentation of GroE-depleted E. coli. The GroE depletion led to a drastic decrease in FtsE, and the cells exhibited a known phenotype associated with impaired FtsE function. In the GroE-depleted filamentous cells, the localizations of FtsA and ZipA, both of which assemble with the FtsZ septal ring before FtsE, were normal, whereas FtsX, the interaction partner of FtsE, and FtsQ, which is recruited after FtsE, did not localize to the ring, suggesting that the decrease in FtsE is a cause of the filamentous morphology. Finally, a reconstituted cell-free translation system revealed that the folding of newly translated FtsE was stringently dependent on GroEL/GroES. Based on these findings, we concluded that FtsE is a target substrate of the GroE system in E. coli cell division.