Plakophilin 1 suppresses keratinocyte innate immune responses through DExD/H helicases.

Plakophilin 1 (PKP1) suppresses keratinocyte innate immune responses by sequestering RNA helicases, preventing excessive inflammation in healthy skin cells.

• Why it matters: Understanding how keratinocytes regulate inflammation is crucial because dysregulation leads to skin fragility, chronic inflammation, and recurrent infections, as seen in EDSFS caused by PKP1 mutations.
• What they did: The study examined PKP1's role in immune regulation by analyzing its interaction with dsRNA-sensing helicases DDX1, DDX3X, DDX21, and DHX15, and its effect on the MDA5-MAVS signaling pathway.
• The result: PKP1 acts as a gatekeeper by sequestering helicases to prevent overactivation of inflammatory genes, and its degradation during immune responses enables rapid inflammation, highlighting its dual role in skin immune homeostasis.