Metabolic and physiological perturbations of Escherichia coli W3100 by bacterial small RNA RyhB
Metabolic and physiological perturbations of Escherichia coli W3100 by bacterial small RNA RyhB
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DOI：
10.1016/j.biochi.2019.04.016
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发表时间：
2019-07-01
期刊：
影响因子：
3.9
通讯作者：
Shi, Yunyu
中科院分区：
文献类型：
--
作者：
Lyu, Yu;Wu, Jihui;Shi, Yunyu
RyhB是大肠杆菌（E. coli）中铁水平的关键调节剂，当细胞质中铁的亚铁形式水平有限时，它有助于保存铁以维持生命的细胞功能。RyhB影响葡萄糖代谢。70%受RyhB调控的基因与代谢有关。我们首次使用基于C-13稳定同位素的METAFoR（代谢通量比分析）技术证明了戊糖磷酸途径的活性在ryhB激活后增加。基于U-C-13葡萄糖的研究表明，通量重新分配增强了丝氨酸和甘氨酸的可逆交换活性，进一步促进了NADPH的形成。此外，在ryhb缺陷细胞中，enner - doudoroff （ED）通路活性被抑制。基于定量生理学的实验强调了ryhb诱导的W3100大肠杆菌细胞在批量培养中活性氧（ROS）水平的显著增加。NADH/NAD（+）和NADPH/NADP（+）比值的同时降低概述了NADH和NADPH在拮抗ryhB活化后形成的过量ROS中的潜在直接作用。我们的观察结果为RyhB的作用提供了一个新的视角，并强调这种小RNA除了作为基因表达的调节剂外，还可以显著影响细胞代谢。(C) 2019 Elsevier B.V.和Societe Francaise de Biochimie et Biologie molecular （SFBBM）。版权所有。
RyhB is a key regulator of iron level in Escherichia coli (E. coli), which assists in conserving iron for life-sustaining cellular functions when cytoplasmic levels of the ferrous form of iron is limited. RyhB affects glucose metabolism. Seventy percent of the genes that are regulated by RyhB are related to metabolism. We demonstrated for the first time that the activity of the pentose phosphate pathway increased upon ryhB activation using a C-13 stable isotope-based technique called METAFoR (Metabolic flux ratio analysis). U-C-13 glucose-based studies showed that the reversible exchange activity of serine and glycine was enhanced by flux redistribution, which further favors NADPH formation. In addition, Entner-Doudoroff (ED) pathway activity was inhibited in the ryhB-defective cells. Quantitative physiology-based experiments highlighted a significant increase in the levels of reactive oxygen species (ROS) in ryhB-induced W3100 E. coli cells in batch culture. A simultaneous decrease in NADH/NAD(+) and NADPH/NADP(+) ratios outlined the potentially direct roles of NADH and NADPH in antagonizing the excess ROS formed after ryhB activation. Our observations offer a new perspective regarding the roles of RyhB and highlight that this small RNA can significantly affect cell metabolism in addition to its role as a regulator of gene expression. (C) 2019 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.