PRY/SPRY domain in tripartite motif-binding protein 39 (TRIM39) and TRIM39-like
This domain, consisting of the distinct N-terminal PRY subdomain followed by the SPRY subdomain, is found at the C-terminus of pyrin, several tripartite motif-containing proteins (TRIMs), including E3 ubiquitin-protein ligase (TRIM21), RET finger protein (RFP)/tripartite motif protein 27 (TRIM27), as well as butyrophilin (Btns) and butyrophilin-like (Btnl) family members, with the exception of Btnl2. Btn and Btnl family members are novel regulators of immune responses, with many of the genes located within the MHC. They are implicated in T-cell inhibition and modulation of epithelial cell-T cell interactions. TRIM21 (also known as RO52, SSA1 or RNF81) is a major autoantigen in autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and Sjorgen's syndrome. TRIM27 (also known as Ret finger protein, RFP or RNF76) negatively regulates CD4 T-cells by ubiquitinating and inhibiting the class II phosphatidylinositol 3 kinase C2beta (PI3K-C2beta), a kinase critical for KCa3.1 channel activation. The PRY/SPRY domain of Pyrin, which is mutated in familial Mediterranean fever patients, interacts with inflammasome components and inhibits proIL-1beta processing.