title: Role of the general stress response during strong overexpression of a heterologous gene in Escherichia coli.
abstract: The strong overexpression of heterologous genes in Escherichia coli often leads to inhibition of cell growth, ribosome destruction, loss of culturability, and induction of stress responses, such as a heat shock-like response. Here we demonstrate that the general stress response, which is connected to the stress response regulator sigmas (sigma38, rpoS gene product), is suppressed during strong overproduction of a heterologous alpha-glucosidase. The mRNA levels of the rpoS and osmY stress genes drastically decrease after induction of the strong overexpression system. It is shown that an rpoS mutation causes a significant loss of cell viability after induction of the expression system. Furthermore, it is demonstrated that an E. coli c/pP mutant, which could be suggested to improve heterologous protein production, is not a good production host if a tac-promoter is used to control the expression of the recombinant gene. Data from this study suggest that the overexpression of the alpha-glucosidase was greatly decreased by sigma factor competition in the clpP mutant, due to the increased sigmas level in this mutant background.
authors.affiliation: Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Schweder
authors.forename: H Y
authors.initials: HY
authors.lastname: Lin
authors.forename: B
authors.initials: B
authors.lastname: Jürgen
authors.forename: A
authors.initials: A
authors.lastname: Breitenstein
authors.forename: S
authors.initials: S
authors.lastname: Riemschneider
authors.forename: V
authors.initials: V
authors.lastname: Khalameyzer
authors.forename: A
authors.initials: A
authors.lastname: Gupta
authors.forename: K
authors.initials: K
authors.lastname: Büttner
authors.forename: P
authors.initials: P
authors.lastname: Neubauer
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D000520:alpha-Glucosidases / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D011994:Recombinant Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D000520:alpha-Glucosidases; C063842:dnaK protein, E coli