Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India.
Department of Biochemistry, Indian Institute of Science, Bangalore, India.
FASEB J. 2021 Apr;35(4):e21475. doi: 10.1096/fj.202002537RR.
Cell signaling relies on second messengers to transduce signals from the sensory apparatus to downstream signaling pathway components. In bacteria, one of the most important and ubiquitous second messenger is the small molecule cyclic diguanosine monophosphate (c-di-GMP). While the biosynthesis, degradation, and regulatory pathways controlled by c-di-GMP are well characterized, the mechanisms through which c-di-GMP controls these processes are not entirely understood. Herein we present the report of a c-di-GMP sensing sensor histidine kinase PdtaS (Rv3220c), which binds to c-di-GMP at submicromolar concentrations, subsequently perturbing signaling of the PdtaS-PdtaR (Rv1626) two-component system. Aided by biochemical analysis, genetics, molecular docking, FRET microscopy, and structural modelling, we have characterized the binding of c-di-GMP in the GAF domain of PdtaS. We show that a pdtaS knockout in Mycobacterium smegmatis is severely compromised in growth on amino acid deficient media and exhibits global transcriptional dysregulation. The perturbation of the c-di-GMP-PdtaS-PdtaR axis results in a cascade of cellular changes recorded by a multiparametric systems' approach of transcriptomics, unbiased metabolomics, and lipid analyses.
细胞信号依赖于第二信使，将信号从感觉器官传递到下游信号通路成分。在细菌中，最重要和最普遍的第二信使之一是小分子环二鸟苷酸（c-di-GMP）。虽然 c-di-GMP 的生物合成、降解和调控途径已经得到很好的描述，但 c-di-GMP 控制这些过程的机制还不完全清楚。在此，我们报告了一种 c-di-GMP 感应传感器组氨酸激酶 PdtaS（Rv3220c），它以亚毫摩尔浓度结合 c-di-GMP，随后干扰 PdtaS-PdtaR（Rv1626）双组分系统的信号。通过生化分析、遗传学、分子对接、FRET 显微镜和结构建模，我们对 PdtaS 的 GAF 结构域中 c-di-GMP 的结合进行了表征。我们表明，分枝杆菌中的 pdtaS 敲除在氨基酸缺乏的培养基上的生长严重受损，并表现出全局转录失调。c-di-GMP-PdtaS-PdtaR 轴的扰动导致细胞变化的级联，这是通过转录组学、无偏代谢组学和脂质分析的多参数系统方法记录的。
