title: Acetylation Regulates Survival of Salmonella enterica Serovar Typhimurium under Acid Stress.
abstract: The ability to acetylate lysine residues is conserved across organisms, and acetylation of lysine residues plays important roles in various cellular functions. Maintaining intracellular pH homeostasis is crucial for the survival of enteric bacteria in the acidic gastric tract. It has been shown that eukaryotes can stabilize the intracellular pH by histone deacetylation. However, it remains unknown whether bacteria can utilize a reversible protein acetylation system to adapt to an acidic environment. Here we demonstrate that protein acetylation/deacetylation is critical for Salmonella enterica serovar Typhimurium to survive in an acidic environment. We used RNA sequencing to analyze the transcriptome patterns under acid stress and found that the transcriptional levels of genes involved in NAD(+)/NADH metabolism were significantly changed, leading to an increase in the intracellular NAD(+)/NADH ratio. Moreover, acid stress downregulated the transcriptional level of pat, encoding acetyltransferase, and genes cyaA and crp, encoding adenylate cyclase and cyclic AMP receptor protein, respectively, which are positive regulators of pat. It was found that the acid signal alerts the tricarboxylic acid cycle to promote the consumption of acetyl coenzyme A (Ac-CoA), an acetyl group donor for the acetylation reaction. A lowered acetylation level not only was the bacterial response to acid stress but also increased the survival rate of S. Typhimurium under acid stress. The pat deletion mutant had a more stable intracellular pH, which paralleled the higher survival rate after acid treatment compared with that of both the wild-type strain and the cobB (encoding deacetylase) deletion mutant. Our data indicate that bacteria can downregulate the protein acetylation level to prevent the intracellular pH from further falling under acid stress, and this work may provide a new perspective to understand the bacterial acid resistance mechanism.
authors.affiliation: Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ren
authors.affiliation: Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sang
authors.affiliation: Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jinjing
authors.initials: J
authors.lastname: Ni
authors.affiliation: Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Tao
authors.affiliation: Department of Infectious Diseases, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Lu
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Key Laboratory for Microbiological Engineering of the Agricultural Environment, Ministry of Agriculture, Nanjing, Jiangsu, China mwzhao@njau.edu.cn yfyao@sjtu.edu.cn.
authors.forename: Mingwen
authors.initials: M
authors.lastname: Zhao
authors.affiliation: Laboratory of Bacterial Pathogenesis, Department of Microbiology and Immunology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China mwzhao@njau.edu.cn yfyao@sjtu.edu.cn.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Yao
mesh_terms: D000107:Acetylation; D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism; D000143:Acids / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D050296:Microbial Viability; D012486:Salmonella typhimurium / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D000123:Acetyltransferases