PRY/SPRY domain in tripartite motif-binding protein 21 (TRIM21) also known as 52kD Ribonucleoprotein Autoantigen (Ro52)
This domain, consisting of the distinct N-terminal PRY subdomain followed by the SPRY subdomain, is found at the C-terminus of TRIM21, which is also known as Sjogren Syndrome Antigen A (SSA), SSA1, 52kD Ribonucleoprotein Autoantigen (Ro52, Ro/SSA, SS-A/Ro) or RING finger protein 81 (RNF81). TRIM21 domains are composed of RING/B-box/coiled-coil core and also known as RBCC proteins. As an E3 ligase, TRIM21 mediates target specificity in ubiquitination; it regulates type 1 interferon and proinflammatory cytokines via ubiquitination of interferon regulatory factors (IRFs). It is up-regulated at the site of autoimmune inflammation, such as cutaneous lupus lesions, indicating a central role in the tissue destructive inflammatory process. It interacts with auto-antigens in patients with Sjogren syndrome and systemic lupus erythematosus, a chronic systemic autoimmune disease characterized by the presence of autoantibodies against the protein component of the human intracellular ribonucleoprotein-RNA complexes and more specifically TRIM21, Ro60/TROVE2 and La/SSB proteins. It binds the Fc part of IgG molecules via its PRY-SPRY domain with unexpectedly high affinity.
Jiyao W et al.(2023). "The conserved domain database in 2023.",