title: Tail-Anchored Inner Membrane Protein ElaB Increases Resistance to Stress While Reducing Persistence in Escherichia coli.
abstract: Host-associated bacteria, such asEscherichia coli, often encounter various host-related stresses, such as nutritional deprivation, oxidative stress, and temperature shifts. There is growing interest in searching for small endogenous proteins that mediate stress responses. Here, we characterized the small C-tail-anchored inner membrane protein ElaB inE. coliElaB belongs to a class of tail-anchored inner membrane proteins with a C-terminal transmembrane domain but lacking an N-terminal signal sequence for membrane targeting. Proteins from this family have been shown to play vital roles, such as in membrane trafficking and apoptosis, in eukaryotes; however, their role in prokaryotes is largely unexplored. Here, we found that the transcription ofelaBis induced in the stationary phase inE. coliand stationary-phase sigma factor RpoS regulateselaBtranscription by binding to the promoter ofelaBMoreover, ElaB protects cells against oxidative stress and heat shock stress. However, unlike membrane peptide toxins TisB and GhoT, ElaB does not lead to cell death, and the deletion ofelaBgreatly increases persister cell formation. Therefore, we demonstrate that disruption of C-tail-anchored inner membrane proteins can reduce stress resistance; it can also lead to deleterious effects, such as increased persistence, inE. coliIMPORTANCEEscherichia colisynthesizes dozens of poorly understood small membrane proteins containing a predicted transmembrane domain. In this study, we characterized the function of the C-tail-anchored inner membrane protein ElaB inE. coliElaB increases resistance to oxidative stress and heat stress, while inactivation of ElaB leads to high persister cell formation. We also demonstrated that the transcription ofelaBis under the direct regulation of stationary-phase sigma factor RpoS. Thus, our study reveals that small inner membrane proteins may have important cellular roles during the stress response.
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Yunxue
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Baiyuan
authors.initials: B
authors.lastname: Li
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Jianyun
authors.initials: J
authors.lastname: Yao
authors.affiliation: Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA.|Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA.
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Wood
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China xxwang@scsio.ac.cn.
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Wang
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D012808:Sigma Factor / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D012808:Sigma Factor; D014157:Transcription Factors
keywords: C-tail-anchored membrane protein; heat shock; oxidative stress; persistence