Uppal Sheetal, Jawali Narendra
Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India,
Arch Microbiol. 2015 Apr;197(3):497-501. doi: 10.1007/s00203-015-1085-4. Epub 2015 Jan 31.
Escherichia coli K-12 contains nine paralogs of CspA, CspA-CspI, collectively known as CspA family of cold-shock proteins (CSPs). In spite of the high degree of similarity among themselves, only five (cspA, B, E, G and I) are induced during cold-stress. In the present study, we show that cspB, cspG and cspI, the members of cspA family, known to be induced in response to cold shock, are regulated by cyclic AMP receptor protein (CRP) , a global regulator involved in sugar metabolism, during growth at 37 °C as well as at 15 °C, as seen by green fluorescent protein (gfp) promoter fusions assays. Interestingly, cspA is selectively regulated by CRP during growth at 15 °C but not at 37 °C. The regulation of cspA, cspB, cspG and cspI by CRP was found to be through an indirect mechanism as determined by electrophoretic mobility shift assay (EMSA). These results substantiate our earlier study demonstrating a role for CRP during growth at low temperature.
大肠杆菌K-12含有CspA的九个旁系同源物，即CspA - CspI，统称为冷休克蛋白（CSP）的CspA家族。尽管它们之间相似度很高，但在冷应激期间只有五个（cspA、B、E、G和I）被诱导表达。在本研究中，我们发现，通过绿色荧光蛋白（gfp）启动子融合分析可知，已知在冷休克反应中被诱导表达的cspA家族成员cspB、cspG和cspI，在37°C以及15°C生长期间受环腺苷酸受体蛋白（CRP）调控，CRP是一种参与糖代谢的全局调控因子。有趣的是，cspA在15°C生长期间受CRP选择性调控，而在37°C时不受调控。通过电泳迁移率变动分析（EMSA）确定，CRP对cspA、cspB、cspG和cspI的调控是通过间接机制实现的。这些结果证实了我们早期的研究，即证明了CRP在低温生长过程中的作用。
