Protein Aggregation Caused by Aminoglycoside Action Is Prevented by a Hydrogen Peroxide Scavenger

SummaryProtein mistranslation causes growth arrest in bacteria, mitochondrial dysfunction in yeast, and neurodegeneration in mammals. It remains poorly understood how mistranslated proteins cause such cellular defects. Here we demonstrate that streptomycin, a bactericidal aminoglycoside that increases ribosomal mistranslation, induces transient protein aggregation in wild-type Escherichia coli. We further determined the aggregated proteome using label-free quantitative mass spectrometry. To identify genes that reduce cellular mistranslation toxicity, we selected from an overexpression library protein products that increased resistance against streptomycin and kanamycin. The selected proteins were significantly enriched in members of the oxidation-reduction pathway. Overexpressing one of these proteins, alkyl hydroperoxide reductase subunit F (a protein defending bacteria against hydrogen peroxide), but not its inactive mutant suppressed aggregated protein formation upon streptomycin treatment and increased aminoglycoside resistance. This work provides in-depth analyses of an aggregated proteome caused by streptomycin and suggests that cellular defense against hydrogen peroxide lowers the toxicity of mistranslation.

Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (250 K)Download as PowerPoint slideHighlights► In-depth coverage of the aggregated proteome induced by streptomycin in E. coli ► Identified proteins are susceptible to oxidation and streptomycin-induced aggregation ► Alkyl hydroperoxide reductase suppresses protein aggregation caused by streptomycin ► Oxidation-reduction proteins increase bacterial resistance against aminoglycosides