Redox biology: Signaling via a peroxiredoxin sensor.

The author discusses hydrogen peroxide that regulates cell signaling pathways through oxidation of specific thiol proteins, and reflects on a study which described a relay system involving peroxiredoxin 2 (Prx2) as a peroxide sensor that oxidizes the mammalian transcription factor STAT3 via a mixed disulfide intermediate. It also discusses two possible molecular mechanisms can be responsible for the transfer of oxidizing equivalents between the thiols of Prx2 and a target such as STAT3.