Understanding of gene regulation in halophilic Archaea: Characterization of the transcriptome, DNA protein interactions, and posttranslational control

古生代的复制、转录和翻译等信息蛋白与真核蛋白具有同源性。相比之下，古生菌的许多代谢蛋白与细菌蛋白关系更密切。在具有“类真核”转录装置的生物体中，对“类细菌”基因的调控尚不清楚。盐生盐生杆菌是研究古生菌基因调控的一个很好的模式系统，因为它在代谢上具有很强的通用性，能够以好氧、微需氧、光营养、发酵和厌氧呼吸方式生长。它能够感知各种化学和物理环境信号。此外，基因组序列已经可用，功能基因组研究已经启动，分子和生化技术也得到了长足的发展。在拟议的项目中，DNA微阵列将用于表征野生型细胞和特定构建的突变体的所有基因的差异表达，以响应不同的环境变化和细胞密度产生的信号。这将允许识别监管层级和电路。选定的基因特异性和全局调节剂的结合部位将在体外和体内进行表征。选定的调控蛋白与基础转录因子以及与DNA的相互作用将在分子水平上进行定量表征。

Informational proteins of Archaea in e.g. replication, transcription and translation, are homologous to eukaryotic proteins. In contrast, many metabolic proteins of Archaea are closer related to bacterial proteins. The regulation of "bacterial-like" genes in organisms with an "eukaryotic-like" transcriptional apparatus is not understood. Halobacterium salinarum is an excellent model system to study archaeal gene regulation, because it is metabolically very versatile and can grow aerobically, microaerobically, phototrophically, fermentatively and by anaerobic respiration. It is able to perceive a variety of chemical and physical environmental signals. Furthermore, the genome sequence is available, functional genomic studies have been initiated and molecular and biochemical techniques are far developed. In the proposed project DNA microarrays will be used to characterize differential expression of all genes of wildtype cells and of specifically constructed mutants in response to different environmental changes and to cell density-generated signals. This will allow to identify regulatory hierachies and circuits. The binding sites of selected gene-specific and of global regulators will be characterized in vitro and in vivo. The interaction of selected regulatory proteins with basal transcription factors and with DNA will be quantitavely characterized on the molecular level.