Anti-Pyrin from rabbit, purified by affinity chromatography

Pyrin (UniProt: O15553; also known as Marenostrin) is encoded by the MEFV (also known as MEF, TRIM20) gene (Gene ID: 4210) in human. Pyrin is a homotrimeric protein that is involved in the regulation of innate immunity and the inflammatory response in response to IFNG/IFN-gamma. It organizes autophagic machinery by serving as a platform for the assembly of ULK1, Beclin 1/BECN1, ATG16L1, and ATG8 family members and recognizes specific autophagy targets, thus coordinating target recognition with assembly of the autophagic apparatus and initiation of autophagy. Pyrin acts as an autophagy receptor for the degradation of several inflammasome components, including CASP1, NLRP1 and NLRP3, hence it may prevent excessive IL-1B- and IL-18-mediated inflammation. Pyrin is expressed in peripheral blood leukocytes, particularly in mature granulocytes and to a lesser extent in monocytes, but not in lymphocytes. It is also detected in spleen, lung and muscle, probably as a result of leukocyte infiltration in these tissues. Its expression is also detected in several myeloid leukemic, colon cancer, and prostate cancer cell lines. Three isoforms of Pyrin have been described that are produced by alternative splicing. Isoform 1 associates with microtubules and with the filamentous actin of perinuclear filaments and peripheral lamellar ruffles. In pre-apoptotic cells, it co-localizes with PYCARD/ASC in large specks (inflammasome). Isoform 2 is shown to be localized to the nucleus.