Cai Xia, Qin Jiaxin, Li Xuelian, Yuan Taoxiong, Yan Bing, Cai Jun
Department of Microbiology, College of Life Sciences Nankai University Tianjin China.
School of Life Science and Engineering Lanzhou University of Technology Lanzhou China.
mLife. 2023 Feb 11;2(1):58-72. doi: 10.1002/mlf2.12055. eCollection 2023 Mar.
Intracellular pH critically affects various biological processes, and an appropriate cytoplasmic pH is essential for ensuring bacterial growth. Glucose is the preferred carbon source for most heterotrophs; however, excess glucose often causes the accumulation of acidic metabolites, lowering the intracellular pH and inhibiting bacterial growth. can effectively cope with glucose-induced stress; unfortunately, little is known about the regulators involved in this process. Here, we document that the target of the dual-function sRNA YhfH, the gene, encodes a LacI-family transcription factor LipR as an intracellular pH regulator when BMB171 is suddenly exposed to glucose. Under glucose conditions, deletion leads to early growth arrest by causing a rapid decrease in intracellular pH (~5.4). Then, the direct targets and a binding motif (GAWAWCRWTWTCAT) of LipR were identified based on the electrophoretic mobility shift assay, the DNase-I footprinting assay, and RNA sequencing, and the gene encoding a key enzyme in glycolysis was directly inhibited by LipR. Furthermore, Ni is considered a possible effector for LipR. In addition to YhfH, the expression was coregulated by itself, CcpA, and AbrB. Our study reveals that LipR plays a balancing role between glucose metabolism and intracellular pH in subjected to glucose stress.
细胞内pH值对各种生物过程有着至关重要的影响，合适的细胞质pH值对于确保细菌生长必不可少。葡萄糖是大多数异养生物的首选碳源；然而，过量的葡萄糖常常导致酸性代谢产物的积累，降低细胞内pH值并抑制细菌生长。[具体细菌名称]能够有效应对葡萄糖诱导的应激；不幸的是，对于参与这一过程的调节因子我们知之甚少。在此，我们证明，当[具体细菌名称]BMB171突然暴露于葡萄糖时，双功能小RNA YhfH的靶标[具体基因名称]编码一种LacI家族转录因子LipR作为细胞内pH调节因子。在葡萄糖条件下，[具体基因名称]缺失会导致细胞内pH值迅速下降（约5.4），从而导致早期生长停滞。然后，基于电泳迁移率变动分析、DNA酶I足迹分析和RNA测序确定了LipR的直接靶标和结合基序（GAWAWCRWTWTCAT），并且糖酵解中一种关键酶的编码基因被LipR直接抑制。此外，镍被认为是LipR的一种可能的效应物。除了YhfH之外，[具体基因名称]的表达还受到其自身、CcpA和AbrB的共同调节。我们的研究表明，在受到葡萄糖应激的[具体细菌名称]中，LipR在葡萄糖代谢和细胞内pH之间起着平衡作用。
