Jones P G, Inouye M
Department of Biochemistry, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854.
Mol Microbiol. 1994 Mar;11(5):811-8. doi: 10.1111/j.1365-2958.1994.tb00359.x.
The cold-shock response of Escherichia coli describes a specific pattern of gene expression in response to abrupt shifts to lower temperatures. This pattern includes the induction of cold-shock proteins, synthesis of proteins involved in transcription and translation, and repression of heat-shock proteins. The identified cold-shock proteins are involved in various cellular functions from supercoiling of DNA to initiation of translation. The major cold-shock protein, CspA, has high sequence similarity with three other E. coli proteins--CspB, CspC, and CspD. Using translational lacZ fusions, cspB was found to be cold-shock inducible at the level of transcription like cspA, while cspC and cspD were not. The Csp proteins, which share sequence similarity with other prokaryotic proteins and with the 'cold-shock domain' of eukaryotic Y-box proteins, may have a function in activating transcription or unwinding or masking RNA molecules. Because the cold-shock response can also be induced by the addition of certain inhibitors of translation, it has been proposed that the state of the ribosome is the physiological sensor for the induction. In addition to E. coli, cold-shock proteins have also been found in other prokaryotic and eukaryotic organisms.
大肠杆菌的冷休克反应描述了一种特定的基因表达模式，该模式是对温度突然降至较低水平的响应。这种模式包括冷休克蛋白的诱导、参与转录和翻译的蛋白质的合成以及热休克蛋白的抑制。已鉴定出的冷休克蛋白参与从DNA超螺旋到翻译起始的各种细胞功能。主要的冷休克蛋白CspA与其他三种大肠杆菌蛋白CspB、CspC和CspD具有高度的序列相似性。利用翻译型lacZ融合体，发现cspB在转录水平上与cspA一样可被冷休克诱导，而cspC和cspD则不能。Csp蛋白与其他原核生物蛋白以及真核生物Y盒蛋白的“冷休克结构域”具有序列相似性，可能在激活转录或解开或掩盖RNA分子方面具有功能。由于添加某些翻译抑制剂也可诱导冷休克反应，因此有人提出核糖体的状态是诱导反应的生理传感器。除了大肠杆菌外，在其他原核生物和真核生物中也发现了冷休克蛋白。
