Anti-TRIM21/SS-A Antibody Picoband® Fluoro488 Conjugated

Tripartite motif-containing protein 21 also known as E3 ubiquitin-protein ligase TRIM21 is a protein that in humans is encoded by the TRIM21 gene. It is mapped to 11p15.4. This gene encodes a member of the tripartite motif (TRIM) family. The TRIM motif includes three zinc-binding domains, a RING, a B-box type 1 and a B-box type 2, and a coiled-coil region. The encoded protein is part of the RoSSA ribonucleoprotein, which includes a single polypeptide and one of four small RNA molecules. The RoSSA particle localizes to both the cytoplasm and the nucleus. RoSSA interacts with autoantigens in patients with Sjogren syndrome and systemic lupus erythematosus. Alternatively spliced transcript variants for this gene have been described but the full-length nature of only one has been determined.

E3 ubiquitin-protein ligase TRIM21; 52 kDa Ro protein; 52 kDa ribonucleoprotein autoantigen Ro/SS-A; RING finger protein 81; RING-type E3 ubiquitin transferase TRIM21; Ro (SS-A) ; Sjoegren syndrome type A antigen; SS-A; Tripartite motif-containing protein 21; TRIM21; RNF81; RO52; SSA1

E3 ubiquitin-protein ligase whose activity is dependent on E2 enzymes, UBE2D1, UBE2D2, UBE2E1 and UBE2E2. Forms a ubiquitin ligase complex in cooperation with the E2 UBE2D2 that is used not only for the ubiquitination of USP4 and IKBKB but also for its self-ubiquitination. Component of cullin-RING-based SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complexes such as SCF (SKP2) -like complexes. A TRIM21-containing SCF (SKP2) -like complex is shown to mediate ubiquitination of CDKN1B ('Thr-187' phosphorylated-form), thereby promoting its degradation by the proteasome. Monoubiquitinates IKBKB that will negatively regulates Tax-induced NF-kappa-B signaling. Negatively regulates IFN-beta production post-pathogen recognition by polyubiquitin-mediated degradation of IRF3. Mediates the ubiquitin-mediated proteasomal degradation of IgG1 heavy chain, which is linked to the VCP-mediated ER-associated degradation (ERAD) pathway. Promotes IRF8 ubiquitination, which enhanced the ability of IRF8 to stimulate cytokine genes transcription in macrophages. Plays a role in the regulation of the cell cycle progression. Enhances the decapping activity of DCP2. Exists as a ribonucleoprotein particle present in all mammalian cells studied and composed of a single polypeptide and one of four small RNA molecules. At least two isoforms are present in nucleated and red blood cells, and tissue specific differences in RO/SSA proteins have been identified. The common feature of these proteins is their ability to bind HY RNAs.2. Involved in the regulation of innate immunity and the inflammatory response in response to IFNG/IFN-gamma. Organizes autophagic machinery by serving as a platform for the assembly of ULK1, Beclin 1/BECN1 and ATG8 family members and recognizes specific autophagy targets, thus coordinating target recognition with assembly of the autophagic apparatus and initiation of autophagy. Acts as an autophagy receptor for the degradation of IRF3, hence attenuating type I interferon (IFN) -dependent immune responses.

1. Frank, M. B. Characterization of DNA binding properties and sequence specificity of the human 52 kDa Ro/SS-A (Ro52) zinc finger protein. Biochem. Biophys. Res. Commun. 259: 665-670, 1999. 2. Frank, M. B., Itoh, K., Fujisaku, A., Pontarotti, P., Mattei, M.-G., Neas, B. R. The mapping of the human 52-kD Ro/SSA autoantigen gene to human chromosome 11, and its polymorphisms. Am. J. Hum. Genet. 52: 183-191, 1993. 3. Itoh, K., Itoh, Y., Frank, M. B. Protein heterogeneity in the human Ro/SSA ribonucleoproteins: the 52- and 60-kD Ro/SSA autoantigens are encoded by separate genes. J. Clin. Invest. 87: 177-186, 1991.