Peptidoglycan recognition proteins (PGRPs) are a key part of the innate immune system's defense against bacteria. PGRPs are now shown to act through a conserved secretion stress–sensing two-component system, which leads to membrane depolarization and the release of cytotoxic hydroxyl radicals. Thus, PGRPs exploit an ancient bacterial stress response to elicit cell death, and this pathway may be targeted to produce improved antimicrobial drugs (pages 676–683).
- Colin Kietzman
- Elaine Tuomanen