Carrier proteins

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).

Enhancer sequences increase gene transcription with the help of a co-activator complex, the Mediator. Another protein complex — cohesin — seems to work with Mediator to bring together enhancers and promoters. See Article p. 430

The signaling intermediates that activate inflammasomes are elusive. New data now show that reactive oxygen species causes TXNIP to associate with NLRP3 and activate the inflammasome.