LipR functions as an intracellular pH regulator in Bacillus thuringiensis under glucose conditions  

作　　者：Xia Cai Jiaxin Qin Xuelian Li Taoxiong Yuan Bing Yan Jun Cai 

机构地区：[1]Department of Microbiology,College of Life Sciences,Nankai University,Tianjin,China [2]School of Life Science and Engineering,Lanzhou University of Technology,Lanzhou,China [3]Key Laboratory of Molecular Microbiology and Technology,Ministry of Education,Tianjin,China [4]Tianjin Key Laboratory of Microbial Functional Genomics,Tianjin,China

出　　处：《mLife》2023年第1期58-72,共15页微生物（英文）

基　　金：supported by the National Key Research and Development Program of China(2018YFA0900100);the National Natural Science Foundation of China(31670081).

摘　　要：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.Bacillus thuringiensis 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 lipR gene,encodes a LacI-family transcription factor LipR as an intracellular pH regulator when B.thuringiensis BMB171 is suddenly exposed to glucose.Under glucose conditions,lipR 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 gapN gene encoding a key enzyme in glycolysis was directly inhibited by LipR.Furthermore,Ni^(2+)is considered a possible effector for LipR.In addition to YhfH,the lipR expression was coregulated by itself,CcpA,and AbrB.Our study reveals that LipR plays a balancing role between glucose metabolism and intracellular pH in B.thuringiensis subjected to glucose stress.

关 键 词：GLUCOSE intracellular pH LacI‐type transcription factor LipR 

分 类 号：Q93[生物学—微生物学]