Pyrin is believed to have both intranuclear and cytoplasmic actions. Within the nucleus it acts via NF-β to either down regulate pro-inflammatory cytokines or conversely, up regulate anti-inflammatory cytokines. Within the cytoplasm, pyrin most likely modulates the cytoskeletal events in neutrophils. It also attenuates the production of IL-1β by inflammasomes.
Pathology
familial mediterranean fever (FMF) (MIM.249100) is caused by mutation in the pyrin gene (MEFV) (MIM.608107)