Osmolarity-dependent control of cellular c-di-AMP levels and characterization of osmolyte transporters in Listeria monocytogenes

单核细胞增生李斯特菌中细胞 c-di-AMP 水平的渗透压依赖性控制和渗透剂转运蛋白的表征

• 批准号: 314704276
• 负责人: Professor Dr. Fabian M. Commichau
• 金额: --
• 依托单位: Fachgebiet Molekulare Mikrobiologie (190 h)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/314704276?language=en
• 关键词: Osmolarity; dependent; control; cellular; di

Cyclic di-AMP is a signalling nucleotide that is produced by many Gram-positive bacteria, including the human pathogen Listeria monocytogenes. C-di-AMP is synthesized and degraded by specific diadenylate cyclases and phosphodiesterases, respectively. For L. monocytogenes and phylogenetically related bacteria it has been shown that c-di-AMP is essential for growth. Several targets have been identified in the past years that bind to c-di-AMP. As yet, none of the known targets of c-di-AMP is essential in the bacteria whose viability, however depends on the signalling nucleotide. Recently, we have shown that the CdaR protein negatively regulates the activity of the L. monocytogenes diadenylate cyclase CdaA. The observation that both proteins are located at the cell envelope, suggests that c-di-AMP metabolism is linked to cell wall homeostasis. Indeed, for many bacteria it has been reported that alterations of the cellular c-di-AMP levels affect integrity of the protective cell envelope. However, the role of c-di-AMP in cell wall metabolism is unknown. In the proposed project we want to identify the signals that are received by CdaR and how c-di-AMP produced by CdaA affects the integrity of the bacterial cell envelope. By applying genetic as well as biochemical approaches we aim to elucidate the interaction network of CdaA and its regulator CdaR. Moreover, we want to perform structural analyses to investigate the molecular details of the protein complexes. We also want to identify substances that inhibit CdaA because the essential diadenylate cyclase is an excellent target for novel antibiotics.

环二-AMP 是一种信号核苷酸，由许多革兰氏阳性细菌产生，包括人类病原体单核细胞增生李斯特菌。 C-di-AMP 分别由特定的二腺苷酸环化酶和磷酸二酯酶合成和降解。对于单核细胞增生李斯特氏菌和系统发育相关细菌来说，c-di-AMP 对于生长至关重要。在过去的几年里，已经确定了几个与 c-di-AMP 结合的靶标。迄今为止，c-di-AMP 的已知靶标都不是细菌所必需的，但细菌的生存能力却取决于信号核苷酸。最近，我们发现 CdaR 蛋白负向调节单核细胞增生李斯特菌二腺苷酸环化酶 CdaA 的活性。这两种蛋白质都位于细胞被膜上，这表明 c-di-AMP 代谢与细胞壁稳态有关。事实上，据报道，对于许多细菌来说，细胞 c-di-AMP 水平的改变会影响保护性细胞膜的完整性。然而，c-di-AMP 在细胞壁代谢中的作用尚不清楚。在拟议的项目中，我们希望确定 CdaR 接收的信号以及 CdaA 产生的 c-di-AMP 如何影响细菌细胞包膜的完整性。通过应用遗传和生化方法，我们的目标是阐明 CdaA 及其调节剂 CdaR 的相互作用网络。此外，我们想要进行结构分析以研究蛋白质复合物的分子细节。我们还想鉴定抑制 CdaA 的物质，因为必需的二腺苷酸环化酶是新型抗生素的绝佳靶标。