title: A small heat shock protein enables Escherichia coli to grow at a lethal temperature of 50°C conceivably by maintaining cell envelope integrity.
abstract: It is essential for organisms to adapt to fluctuating growth temperatures. Escherichia coli, a model bacterium commonly used in research and industry, has been reported to grow at a temperature lower than 46.5°C. Here we report that the heterologous expression of the 17-kDa small heat shock protein from the nematode Caenorhabditis elegans, CeHSP17, enables E. coli cells to grow at 50°C, which is their highest growth temperature ever reported. Strikingly, CeHSP17 also rescues the thermal lethality of an E. coli mutant deficient in degP, which encodes a protein quality control factor localized in the periplasmic space. Mechanistically, we show that CeHSP17 is partially localized in the periplasmic space and associated with the inner membrane of E. coli, and it helps to maintain the cell envelope integrity of the E. coli cells at the lethal temperatures. Together, our data indicate that maintaining the cell envelope integrity is crucial for the E. coli cells to grow at high temperatures and also shed new light on the development of thermophilic bacteria for industrial application.
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, and Center for Protein Science, Peking University, Beijing, China.
authors.forename: Anastasia N
authors.initials: AN
authors.lastname: Ezemaduka
authors.forename: Jiayu
authors.initials: J
authors.lastname: Yu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Shi
authors.forename: Kaiming
authors.initials: K
authors.lastname: Zhang
authors.forename: Chang-Cheng
authors.initials: CC
authors.lastname: Yin
authors.forename: Xinmiao
authors.initials: X
authors.lastname: Fu
authors.forename: Zengyi
authors.initials: Z
authors.lastname: Chang
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D017353:Gene Deletion; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D050296:Microbial Viability; D009154:Mutation; D033903:Periplasmic Proteins / Q000235:genetics / Q000378:metabolism; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
chemical_list: D029742:Caenorhabditis elegans Proteins; D006360:Heat-Shock Proteins; D033903:Periplasmic Proteins; C061682:DegP protease; D012697:Serine Endopeptidases