Zentrum für Molekulare Biologie Heidelberg, DKFZ-ZMBH Alliance, Universität Heidelberg, Heidelberg, Germany.
Cold Spring Harb Perspect Biol. 2011 Apr 1;3(4):a004366. doi: 10.1101/cshperspect.a004366.
Bacterial cells are frequently exposed to dramatic fluctuations in their environment, which cause perturbation in protein homeostasis and lead to protein misfolding. Bacteria have therefore evolved powerful quality control networks consisting of chaperones and proteases that cooperate to monitor the folding states of proteins and to remove misfolded conformers through either refolding or degradation. The levels of the quality control components are adjusted to the folding state of the cellular proteome through the induction of compartment specific stress responses. In addition, the activities of several quality control components are directly controlled by these stresses, allowing for fast activation. Severe stress can, however, overcome the protective function of the proteostasis network leading to the formation of protein aggregates, which are sequestered at the cell poles. Protein aggregates are either solubilized by AAA+ chaperones or eliminated through cell division, allowing for the generation of damage-free daughter cells.
细菌细胞经常面临其环境的剧烈波动，这会导致蛋白质平衡失调，导致蛋白质错误折叠。因此，细菌进化出了强大的质量控制网络，由伴侣蛋白和蛋白酶组成，共同监测蛋白质的折叠状态，并通过重折叠或降解去除错误折叠的构象。通过诱导特定隔室的应激反应，质量控制组件的水平可以根据细胞蛋白质组的折叠状态进行调整。此外，几种质量控制组件的活性直接受到这些应激的控制，从而可以快速激活。然而，严重的应激可以克服质平衡网络的保护功能，导致蛋白质聚集体的形成，这些聚集体被隔离在细胞的两极。蛋白质聚集体要么被 AAA+伴侣蛋白溶解，要么通过细胞分裂消除，从而产生无损伤的子细胞。
