Identification of the Phr-dependent heat shock regulon in the hyperthermophilic archaeon, Thermococcus kodakaraensis
Identification of the Phr-dependent heat shock regulon in the hyperthermophilic archaeon, Thermococcus kodakaraensis
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DOI：
10.1093/jb/mvp177
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发表时间：
2010-03-01
影响因子：
2.7
通讯作者：
Imanaka, Tadayuki
中科院分区：
文献类型：
--
作者：
Kanai, Tamotsu;Takedomi, Shogo;Imanaka, Tadayuki
超嗜热古菌Thermococcus kodakaraensis具有一个与Pyrococcus furiosus Phr（Pf-Phr）同源的转录调节因子（Tk-Phr）。Pf-Phr是一种转录调节因子，在正常生长温度下抑制编码小热休克蛋白（sHSP）、AAA（+）ATP酶和Pf-Phr本身的基因。在此，我们构建了Tk-Phr的基因破坏菌株（菌株KHR 1）。KHR 1细胞在不同温度下表现出与野生型菌株相似的比生长速率。在80 ℃下生长的KHR 1和野生型细胞之间进行全基因组微阵列分析。超过20个基因的转录水平在KHR 1细胞中显著更高。大多数基因在其5 '侧翼区含有与Pf-Phr几乎相同的序列基序。Tk-Phr调节子包括编码sHSP、AAA（+）ATP酶、前折叠蛋白、RecA超家族ATP酶和Tip 49的基因。另一方面，超过一半的成员在调节子编码保守/假设的蛋白质，提高了这些蛋白质参与未知的过程中的热休克反应的可能性。与此相反，Tk-Phr缺失并没有导致先前显示对热休克有反应的伴侣蛋白（CpkB）的转录和蛋白水平的显著增加，这表明T.科达卡拉
The hyperthermophilic archaeon Thermococcus kodakaraensis harbors a putative transcriptional regulator (Tk-Phr) that is orthologous to the Pyrococcus furiosus Phr (Pf-Phr). Pf-Phr, a transcriptional regulator, represses genes encoding the small heat shock protein (sHSP), AAA(+) ATPase and Pf-Phr itself under normal growth temperatures. Here we constructed a gene disruption strain of Tk-Phr (strain KHR1). KHR1 cells showed similar specific growth rates with those of the wild-type strain under various temperatures. A whole genome microarray analysis was performed between KHR1 and wild-type cells grown at 80 degrees C. Transcript levels of more than 20 genes were significantly higher in KHR1 cells. Most genes contained a sequence motif virtually identical to that of Pf-Phr in their 5'-flanking regions. The Tk-Phr regulon included genes encoding sHSP, AAA(+) ATPase, prefoldin, RecA superfamily ATPase and Tip49. On the other hand, more than half of the members in the regulon encoded conserved/hypothetical proteins, raising the possibility that these proteins participate in unidentified processes of the heat shock response. In contrast, Tk-Phr deletion did not lead to dramatic increase in transcript and protein levels of a chaperonin (CpkB) previously shown to respond to heat shock, suggesting the presence of a second, Phr-independent heat shock response mechanism in T. kodakaraensis.