Unravelling archaeal signal transduction networks

可逆的蛋白质磷酸化是信号转导的主要机制，它使细胞能够通过控制蛋白质的功能特性来响应外部刺激，从而快速响应环境变化。与我们对真核生物和细菌中蛋白质磷酸化的了解相比，我们对生命的第三个领域--细胞中的蛋白质磷酸化过程知之甚少。Crenarchaeota依赖于Hanks（真核）型蛋白激酶对Ser、Thr和Tyr的蛋白磷酸化，而不存在常见的细菌型双组分系统（对His和Asp的磷酸化）。为了首次深入了解古细菌中蛋白磷酸化的作用，对硫化叶目两个成员的磷酸蛋白质组进行了分析。这些研究揭示了大量的磷蛋白，具有意想不到的高数量的酪氨酸磷酸化和响应于碳源（硫磺硫化叶菌）的蛋白磷酸化的主要变化以及蛋白磷酸酶缺失（硫磺硫化叶菌）。酸热菌）。Saci-PTP和Saci-PP 2A两种蛋白磷酸酶在S. Acidocaldarius导致Saci-PTP没有明显的表型，然而，Saci-PP 2A的缺失导致细胞增大和群集测定中的运动性增强。基于这项研究，我们确定了一些监管机构和其他因素，影响表达的古菌，古菌运动结构，在蛋白磷酸化依赖的方式。为了进一步阐明蛋白磷酸酶和蛋白激酶的生理功能，本文对S.表达酸热菌，并构建相应的缺失菌株。这种方法允许的第一个洞察古菌调节网络和中央碳水化合物代谢的信号转导的调节。在未来的研究中，我们将继续研究调节（去）磷酸化网络的不同参与者。接下来，我们将研究不同参与者之间的相互作用，以揭示这些网络的层次结构。

Reversible protein phosphorylation is the main mechanism of signal transduction that enables cells to rapidly respond to environmental changes by controlling the functional properties of proteins in response to external stimuli. Compared to our knowledge of protein phosphorylation in Eukaryotes and Bacteria, little is still known about this process in the third domain of life, the Archaea. Crenarchaeota depend on protein phosphorylation on Ser, Thr and Tyr by Hanks (eukaryotic)-type protein kinases and common bacterial-type two component systems (phosphorylation on His and Asp) are absent. To gain first insights into the role of protein phosphorylation in archaea, the phoshoproteome of two members of the Sulfolobales were analyzed. These studies revealed a high amount of phospho-proteins with an unexpected high number of tyrosine phosphorylation and major changes in protein phosphorylation in response to carbon source (Sulfolobus solfataricus) as well as protein phosphatase deletion (S. acidocaldarius). Deletion of the two identified protein phosphatases, Saci-PTP and Saci-PP2A, in S. acidocaldarius resulted in no obvious phenotype for the Saci-PTP, however, deletion of Saci-PP2A led to enlarged cells and hypermotility in swarming assays. Based on this study, we identified a number of regulators and other factors that influence the expression of the archaellum, the archaeal motility structure, in a protein phosphorylation dependent manner. To further unravel the physiological function of protein phosphatases and protein kinases the enzymes from S. acidocaldarius were expressed and the respective deletion strains were constructed. This approach allowed for first insights into the regulation of the archaellum regulatory network and central carbohydrate metabolism by signal transduction. In future studies we will continue to investigate the different players of the regulatory (de)phosphorylation network. Further on we will study the interplay of the different players in order to unravel the hierarchical structures of these networks.