Structural biochemistry of c-di-AMP degrading phosphodiesterases and their regulation

c-di-AMP降解磷酸二酯酶的结构生物化学及其调控

• 批准号: 302305705
• 负责人: Privatdozent Dr. Gregor Witte
• 金额: --
• 依托单位: Genzentrum - Laboratorium für molekulare Biologie
• 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 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/302305705?language=en
• 关键词: Structural; biochemistry; di; AMP; degrading

Nucleotide second messengers are key components of signal transduction events that link external/internal signals to the cellular response of the cell. The discovery of c-di-AMP as a new and also essential bacterial second messenger opened up a new field in bacterial signaling. Whereas a set of proteins in the c-di-AMP pathway has been already been characterized, the interplay of proteins and connectivity in the c-di-AMP regulatory processes is yet still unclear. Due to the fact that c-di-AMP is essential (for the bacteria synthesizing it) and the fact that changes in the c-di-AMP level have dramatic effect on the cells, altering the concentration of c-di-AMP might be a potential target in antimicrobial therapy. We aim to analyze the degradation of c-di-AMP by specific phosphodiesterases (PDE) carrying a DHH-DHHA1-domain that is responsible for the hydrolysis of the cyclic dinucleotide. Interestingly, two subfamilies of these DHH-type PDE have been described, one membrane protein-type (GdpP) possessing also additional regulatory domains (GGDEF and PAS) and one cytosolic PDE only comprising the DHH-DHHA1-domain. Whereas the first group degrades c-di-AMP to 5-pApA, the latter is able to degrade both c-di-AMP but also 5-pApA to AMP. We aim to use biochemical, biophysical and structural methods (supported by in vivo methods) to elucidate the structure function relationship of these two types of PDEs. We will try to identify the structural differences between the two DHH-type PDEs leading to different products and also try to shed light on the regulation of GdpP-type PDEs by its accessory domains (GGDEF and PAS).

核苷酸第二信使是信号转导事件的关键组成部分，它将外部/内部信号与细胞的细胞反应联系起来。C-di-AMP作为一种新的、也是必不可少的细菌第二信使的发现，开辟了细菌信号转导的新领域。虽然c-di-AMP途径中的一系列蛋白质已经被鉴定，但c-di-AMP调控过程中蛋白质和连接性之间的相互作用仍然不清楚。由于c-di-AMP对于合成c-di-AMP的细菌来说是必不可少的，而且c-di-AMP水平的变化对细胞有很大的影响，因此改变c-di-AMP的浓度可能成为抗菌治疗的一个潜在靶点。我们的目标是分析携带DHH-DHHA1结构域的特定磷酸二酯酶(PDE)对c-diAMP的降解，该结构域负责降解环二核苷酸。有趣的是，这些DHH型PDE的两个亚家族已被描述，一个膜蛋白类型(GdpP)也具有额外的调节域(GGDEF和PAS)和一个细胞质PDE只包含DHH-DHHA1-结构域。前者能将c-di-AMP降解为5-PAPA，后者既能降解c-di-AMP，又能将5-PapA降解为AMP。我们的目标是利用生化、生物物理和结构方法(以体内方法为支撑)来阐明这两类PDE的结构和功能关系。我们将试图确定导致不同产物的两个DHH型PDE之间的结构差异，并试图阐明其附属结构域(GGDEF和PAS)对GdpP型PDE的调控。