VanBogelen R A, Neidhardt F C
Department of Microbiology and Immunology, University of Michigan, Ann Arbor 48109-0620.
Proc Natl Acad Sci U S A. 1990 Aug;87(15):5589-93. doi: 10.1073/pnas.87.15.5589.
Nearly all cells respond to an increase in temperature by inducing a set of proteins, called heat shock proteins (HSPs). Because a large number of other stress conditions induce the HSPs (or at least the most abundant ones), this response is often termed the universal stress response. However, a careful study of conditions that truly mimic a temperature shift suggested that these proteins are induced in response to a change in the translational capacity of the cell. To test this directly, Escherichia coli cells were treated with antibiotics that target the prokaryotic ribosome. Two-dimensional gels were used to evaluate the ability of these drugs to alter the rate of synthesis of the HSPs. One group of antibiotics induced the HSPs, whereas a second group repressed the HSPs and induced another set of proteins normally induced in response to a cold shock. Depending on the concentration used, the induction of the heat or cold shock proteins mimicked a mild or severe temperature shift. In addition, antibiotics of the cold shock-inducing group were found to block high temperature induction of the HSPs. The results implicate the ribosome as a prokaryotic sensor for the heat and cold shock response networks, a role it may serve in eukaryotes as well.
几乎所有细胞都会通过诱导一组名为热休克蛋白（HSPs）的蛋白质来应对温度升高。由于大量其他应激条件也会诱导HSPs（或至少是最丰富的那些），这种反应通常被称为普遍应激反应。然而，对真正模拟温度变化的条件进行的仔细研究表明，这些蛋白质是在细胞翻译能力发生变化时被诱导产生的。为了直接验证这一点，用靶向原核核糖体的抗生素处理大肠杆菌细胞。二维凝胶用于评估这些药物改变HSPs合成速率的能力。一组抗生素诱导HSPs，而另一组则抑制HSPs并诱导另一组通常在冷休克反应中被诱导的蛋白质。根据所用浓度的不同，热休克蛋白或冷休克蛋白的诱导模拟了轻度或重度温度变化。此外，发现诱导冷休克的那组抗生素会阻断HSPs的高温诱导。这些结果表明核糖体是原核生物热休克和冷休克反应网络的传感器，它在真核生物中可能也发挥着同样的作用。
