Hirsch Christian, Gauss Robert, Sommer Thomas
Max-Delbrück Center for Molecular Medicine, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
Trends Cell Biol. 2006 Dec;16(12):657-63. doi: 10.1016/j.tcb.2006.10.006. Epub 2006 Nov 3.
Proteins damaged by stressors such as heat, oxidizing conditions or toxic agents are deleterious to cells and must be properly taken care of. Accordingly, misfolded proteins trigger a cellular stress response that aims to either repair defective polypeptides or eliminate faulty elements when salvage is not possible. This stress response provides time for additional stressor-specific pathways that adapt the cell to the changed environment if necessary. Recent studies have investigated how proteins that frustrate the folding machinery are recognized and cleared from the cell. Surprisingly, these clearance mechanisms are not restricted to the protein level. The stress response can also eliminate the mRNA of polypeptides that are refractory to folding.
受热、氧化环境或有毒物质等应激源损伤的蛋白质对细胞有害，必须得到妥善处理。因此，错误折叠的蛋白质会引发细胞应激反应，其目的要么是修复有缺陷的多肽，要么在无法挽救时清除错误成分。这种应激反应为其他应激源特异性途径提供了时间，以便在必要时使细胞适应变化的环境。最近的研究调查了那些阻碍折叠机制的蛋白质是如何被识别并从细胞中清除的。令人惊讶的是，这些清除机制并不局限于蛋白质水平。应激反应还可以清除难以折叠的多肽的信使核糖核酸。
