Regulation of gene expression during environmental adaptation in hyperthermophiles

极端嗜热古菌能够适应环境条件的变化，尽管它们的基因组很小。本研究主要探讨极端嗜热古菌Thermococcus kodakarensis在环境适应过程中的基因表达调控。我们鉴定出了可能在Ni^2+转运中起作用的NiR依赖性调节子和可能在热休克反应中起作用的Phr依赖性调节子。我们还发现一对PIN结构域蛋白和假想蛋白参与几丁质降解基因的阻遏，它们在整个基因组中作为一个全局因子参与各种基因的表达调控，并且这些蛋白相互作用形成一个复合物。此外，在超嗜热菌中可能的蛋白激酶基因的破坏导致许多蛋白质的细胞内量的变化，这表明通过蛋白质磷酸化的调节系统的存在。

Hyperthermophilic archaea are capable of adapting to changes in environmental conditions in spite of their small set of genes. This study focused on regulation of gene expression during environmental adaptation in the hyperthermophilic archaeon Thermococcus kodakarensis. We identified the NikR-dependent regulon probably functional in Ni^<2+>-transport, and Phr-dependent regulon for heat-shock responses. We also found that a pair of PIN domain protein and hypothetical protein, involved in repression of chitin-degradation genes, acted as a global factor for expression regulation of various gene in the overall genome, and the proteins interacted to each other to form a complex. Moreover, disruption of probable protein kinase gene(s) in the hyperthermophile resulted in changes of intracellular amount of many proteins, suggesting the presence of regulation systems through protein phosphorylation.