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

PKP1 suppresses keratinocyte innate immune responses by sequestering DExD/H helicases, preventing excessive inflammation in healthy skin cells.

• Why it matters: Understanding how keratinocytes regulate inflammation is crucial because dysregulation, as seen in EDSFS, leads to skin fragility, chronic inflammation, and recurrent infections. This knowledge could inform treatments for inflammatory skin disorders.
• What they did: The study examined PKP1’s role in innate immunity by showing it sequesters dsRNAs that activate DExD/H helicases (DDX1, DDX3X, DDX21, DHX15), limiting MDA5-MAVS signaling and cytokine production, with PKP1 degradation during immune activation.
• The result: Findings suggest PKP1 acts as a gatekeeper preventing excessive inflammation in keratinocytes, and its rapid degradation during immune responses enables a swift inflammatory reaction, highlighting its dual role in barrier integrity and immune regulation.