Role of a cell wall assembly factor in enterococcal antimicrobial resistance

项目摘要 几乎所有的革兰氏阳性细菌都合成一种跨膜的Ser/Thr激酶，其含有3-5 细胞外PASTA结构域（“PASTA激酶”），控制关键过程，包括抗生素 抗性、毒素产生、毒力或细胞分裂;在某些细菌中，这种激酶对于 生存能力。因此，这些激酶代表了新疗法的有吸引力的靶标。然而，一个基本的 了解该家族中激酶的功能机制，以感知环境 缺乏体内刺激并处理信息以协调适应性生物反应。 这些信息对于开发新的治疗方法至关重要。研究 这里提出的旨在帮助解决这一差距，阐明基本方面的功能， 该家族中的代表性激酶，即粪肠球菌中的IreK激酶，我们已经证明， E的固有电阻所需。粪便中存在的细胞壁活性抗生素和洗涤剂 胆汁，如胆酸盐。这项研究旨在阐明IreK功能的新见解 激酶与其他细胞壁组装因子的物理和功能关系。 粪便特别是，我们将定义一种蛋白质复合物的组成，这种蛋白质复合物被认为参与了 细胞壁组装，评估其在内在抗菌素耐药性中的作用，并检查其相互作用， 了解IreK如何履行其职责。这项工作有 建立细菌中PASTA激酶跨膜信号转导新模型的潜力， 为抗菌素耐药性、细胞壁完整性的协调、毒力和 革兰氏阳性菌的其他过程。

PROJECT SUMMARY Nearly all Gram-positive bacteria synthesize a transmembrane, Ser/Thr kinase containing 3-5 extracellular PASTA-domains (‘PASTA kinase’) that controls critical processes including antibiotic resistance, toxin production, virulence, or cell division; in some bacteria this kinase is essential for viability. As such, these kinases represent attractive targets for new therapeutics. However, a basic understanding of the mechanisms by which kinases in this family function to perceive environmental stimuli in vivo and process that information to coordinate adaptive biological responses is lacking. Such information is critical to inform development of new therapeutic approaches. The research proposed here seeks to help address this gap by elucidating fundamental aspects of function for a representative kinase in this family, the IreK kinase in Enterococcus faecalis, which we have shown is required for intrinsic resistance of E. faecalis to cell-wall-active antibiotics and to detergents present in bile, such as cholate. This research is designed to elucidate new insights into the function of the IreK kinase by exploring its physical and functional relationships with other cell wall assembly factors in E. faecalis. In particular, we will define the composition of a protein complex thought to be involved in cell wall assembly, assess its role in intrinsic antimicrobial resistance, and examine its interactions both physical and functional with IreK to understand how IreK carries out its duties. This work has the potential to establish a new model for transmembrane signaling by PASTA kinases in bacteria and provide new insights into antimicrobial resistance, coordination of cell wall integrity, virulence and other processes in Gram-positive bacteria.