HipA-mediated antibiotic persistence via phosphorylation of the glutamyl-tRNA-synthetase

Nat Commun. 2013;4:3001. doi: 10.1038/ncomms4001.

Abstract

Bacterial persistence has been shown to be an underlying factor in the failure of antibiotic treatments. Although many pathways, among them the stringent response and toxin-antitoxin modules, have been linked to antibiotic persistence, a clear molecular mechanism for the growth arrest that characterizes persistent bacteria remained elusive. Here, we screened an expression library for putative targets of HipA, the first toxin linked to persistence, and a serine/threonine kinase. We found that the expression of GltX, the glutamyl-tRNA-synthetase, reverses the toxicity of HipA and prevents persister formation. We show that upon HipA expression, GltX undergoes phosphorylation at Ser239, its ATP-binding site. This phosphorylation leads to accumulation of uncharged tRNA(Glu) in the cell, which results in the activation of the stringent response. Our findings demonstrate a mechanism for persister formation by the hipBA toxin-antitoxin module and provide an explanation for the long-observed connection between persistence and the stringent response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / metabolism
  • Binding Sites
  • Cloning, Molecular
  • Drug Resistance, Bacterial / genetics*
  • Escherichia coli / drug effects
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial*
  • Gene Library
  • Glutamate-tRNA Ligase / metabolism*
  • Phenotype
  • Phosphorylation
  • Serine / metabolism
  • Time Factors

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Escherichia coli Proteins
  • hipA protein, E coli
  • Serine
  • Adenosine Triphosphate
  • Glutamate-tRNA Ligase