THE DNAK CHAPERONE MODULATES THE HEAT-SHOCK RESPONSE OF ESCHERICHIA-COLI BY BINDING TO THE SIGMA-32 TRANSCRIPTION FACTOR
THE DNAK CHAPERONE MODULATES THE HEAT-SHOCK RESPONSE OF ESCHERICHIA-COLI BY BINDING TO THE SIGMA-32 TRANSCRIPTION FACTOR
复制标题
DOI：
10.1073/pnas.89.8.3516
复制
发表时间：
1992-04-15
影响因子：
11.1
通讯作者：
GEORGOPOULOS, C
中科院分区：
文献类型：
--
作者：
LIBEREK, K;GALITSKI, TP;GEORGOPOULOS, C
热休克反应和热休克蛋白在进化过程中一直是保守的。在大肠杆菌中，热休克反应由sigma-32转录因子正调控，并由热休克蛋白本身的子集负调控。为了理解热休克反应的调节，我们将σ-32多肽纯化至均一。在纯化过程中，我们发现大部分过表达的sigma-32多肽与普遍保守的DnaK热休克蛋白（70 kDa热休克蛋白，HSP 70的原核等价物）共纯化。进一步的实验证实，纯化的σ-32与DnaK结合，并且该复合物在ATP存在下被破坏。与dnaK 756突变体细菌在所有温度下过表达热休克蛋白的事实一致，纯化的DnaK 756突变体蛋白不明显结合σ-32。
The heat shock response and the heat shock proteins have been conserved across evolution. In Escherichia coli, the heat shock response is positively regulated by the sigma-32 transcriptional factor and negatively regulated by a subset of the heat shock proteins themselves. In an effort to understand the regulation of the heat shock response, we have purified the sigma-32 polypeptide to homogeneity. During the purification procedure, we found that a large fraction of the overexpressed sigma-32 polypeptide copurified with the universally conserved DnaK heat shock protein (the prokaryotic equivalent of the 70-kDa heat shock protein, HSP70). Further experiments established that purified sigma-32 bound to DnaK and that this complex was disrupted in the presence of ATP. Consistent with the fact that dnaK756 mutant bacteria overexpress heat shock proteins at all temperatures, purified DnaK756 mutant protein did not appreciably bind to sigma-32.