Seroatlas · Human Serome Atlas

TRIM21

E3 ubiquitin-protein ligase TRIM21

Also known as: RNF81, RO52, RO52_HUMAN, SSA1

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P19474
Gene
TRIM21
Ensembl
ENSG00000132109
Chromosome
11
Canonical length
475 aa
Protein class
Enzymes, Plasma proteins, Predicted intracellular proteins
Subcellular location
Nucleoplasm
Quaternary structure
Homotrimer

OverviewNCBI Gene

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. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

475 residues, UniProt reviewed canonical sequence.

>P19474|TRIM21
     1  MASAARLTMM WEEVTCPICL DPFVEPVSIE CGHSFCQECI SQVGKGGGSV CPVCRQRFLL
    61  KNLRPNRQLA NMVNNLKEIS QEAREGTQGE RCAVHGERLH LFCEKDGKAL CWVCAQSRKH
   121  RDHAMVPLEE AAQEYQEKLQ VALGELRRKQ ELAEKLEVEI AIKRADWKKT VETQKSRIHA
   181  EFVQQKNFLV EEEQRQLQEL EKDEREQLRI LGEKEAKLAQ QSQALQELIS ELDRRCHSSA
   241  LELLQEVIIV LERSESWNLK DLDITSPELR SVCHVPGLKK MLRTCAVHIT LDPDTANPWL
   301  ILSEDRRQVR LGDTQQSIPG NEERFDSYPM VLGAQHFHSG KHYWEVDVTG KEAWDLGVCR
   361  DSVRRKGHFL LSSKSGFWTI WLWNKQKYEA GTYPQTPLHL QVPPCQVGIF LDYEAGMVSF
   421  YNITDHGSLI YSFSECAFTG PLRPFFSPGF NDGGKNTAPL TLCPLNIGSQ GSTDY

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against TRIM21 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Cell surface
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.34
Highest tissue expression
31 nTPM

Expression across tissuesHPA

Tissue

  • spleen: 31 nTPM
  • bone marrow: 26 nTPM
  • lymph node: 22 nTPM
  • lung: 22 nTPM
  • tonsil: 22 nTPM
  • ovary: 21 nTPM

Single-cell type

  • neutrophils: 36 nCPM
  • kupffer cells: 15 nCPM
  • monocyte progenitors: 15 nCPM
  • extravillous trophoblasts: 13 nCPM
  • neutrophil progenitors: 13 nCPM
  • cholangiocytes: 13 nCPM

Immune cell

  • neutrophil: 355 nTPM
  • eosinophil: 313 nTPM
  • total PBMC: 175 nTPM
  • intermediate monocyte: 140 nTPM
  • classical monocyte: 133 nTPM
  • non-classical monocyte: 131 nTPM

Brain region

  • medulla oblongata: 10 nTPM
  • thalamus: 9.6 nTPM
  • spinal cord: 9.1 nTPM
  • white matter: 8 nTPM
  • choroid plexus: 7.8 nTPM
  • pons: 7.6 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about TRIM21.

Disease | ImmuneIEDB

Conditions an epitope on TRIM21 was assayed in.

Disease | AutoantibodyPubMed

Conditions in which antibodies against TRIM21 are reported. Each links to that disease's full target list.

Showing 19 of 22 — disease pages carrying at least 10 antigens.

ReferencesPubMed · IEDB

Publications for TRIM21 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Reference: AutoantibodyPubMed

344 publications

Show 20 more of 344 total

Reference: B cellIEDB

8 publications

Show 3 more

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. IEDB — curated epitope assays from the Immune Epitope Database (Vita et al., Nucleic Acids Research 2019). Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
1.12
gnomAD pLI
0
gnomAD missense Z
-0.29
DepMap mean gene effect
0.12
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of TRIM21 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads TRIM21 as an antibody target. Whether an autoantibody or antibody against TRIM21 could matter depends on whether native TRIM21 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

TRIM21 is annotated at the cell surface, where native TRIM21 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Source-annotated serology context

The source annotations explicitly mention antibody, autoantibody, autoantigen, or autoimmune context. This is biological context, not study-specific reactivity.

  • RoSSA interacts with autoantigens in patients with Sjogren syndrome and systemic lupus erythematosus.

Canonical record: https://seroatlas.com/gene/TRIM21. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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