Hoerter J, Eisenstark A
Department of Natural Sciences, Stephens College, Columbia, MO 65215.
J Photochem Photobiol B. 1990 Jul;6(3):283-9. doi: 10.1016/1011-1344(90)85098-h.
When Escherichia coli cells are stressed by hydrogen peroxide (H2O2), synthesis of a large number of proteins is repressed, while several other proteins are induced. Since there is evidence that some lethal effects of near-UV (NUV) radiation may be directly or indirectly due to hydrogen peroxide generated by NUV light, treatment of cells with NUV radiation or H2O2 might be expected to repress and induce the same set of proteins. In this study, we compared the effects of H2O2 and NUV irradiation on patterns of protein induction and/or repression which were separate from the 4-thiouridine-dependent response using growth delay mutants (nuv). Concentrating initially on the proteins that ceased synthesis following NUV irradiation in an nuv mutant, we observed that these were not the same as those that ceased synthesis following H2O2 treatment. Inspection of two-dimensional polyacrylamide gel electrophoresis proteins indicated that NUV irradiation repressed synthesis of a different set of proteins, although there was some overlap between the two (45%). It was also observed that the new proteins which appeared after each of the two treatments were different. This suggests that the induction and/or repression of new proteins following NUV irradiation is not triggered solely via oxidative stress, although there is some overlap between the proteins that are induced or repressed following the two treatments.
当大肠杆菌细胞受到过氧化氢（H₂O₂）胁迫时，大量蛋白质的合成受到抑制，而其他几种蛋白质则被诱导合成。由于有证据表明近紫外（NUV）辐射的某些致死效应可能直接或间接归因于NUV光产生的过氧化氢，因此用NUV辐射或H₂O₂处理细胞可能会抑制和诱导同一组蛋白质。在本研究中，我们比较了H₂O₂和NUV辐射对蛋白质诱导和/或抑制模式的影响，这些模式与使用生长延迟突变体（nuv）的4-硫尿苷依赖性反应不同。最初聚焦于nuv突变体中经NUV辐射后停止合成的蛋白质，我们观察到这些蛋白质与经H₂O₂处理后停止合成的蛋白质不同。对二维聚丙烯酰胺凝胶电泳蛋白质的检查表明，NUV辐射抑制了另一组不同蛋白质的合成，尽管两者之间存在一些重叠（45%）。还观察到两种处理后出现的新蛋白质是不同的。这表明，NUV辐射后新蛋白质的诱导和/或抑制并非仅通过氧化应激触发，尽管两种处理后诱导或抑制的蛋白质之间存在一些重叠。
