Seroatlas · Human Serome Atlas

CR2

Complement receptor type 2

Also known as: C3DR, CD21, CR2_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P20023
Gene
CR2
Ensembl
ENSG00000117322
Chromosome
1
Canonical length
1033 aa
Protein class
CD markers, Disease related genes, Human disease related genes, Plasma proteins, Predicted intracellular proteins, Predicted membrane proteins

OverviewNCBI Gene

This gene encodes a membrane protein, which functions as a receptor for Epstein-Barr virus (EBV) binding on B and T lymphocytes. Genetic variations in this gene are associated with susceptibility to systemic lupus erythematosus type 9 (SLEB9). Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Sep 2009]

Canonical amino-acid sequenceUniProt

1033 residues, UniProt reviewed canonical sequence.

>P20023|CR2
     1  MGAAGLLGVF LALVAPGVLG ISCGSPPPIL NGRISYYSTP IAVGTVIRYS CSGTFRLIGE
    61  KSLLCITKDK VDGTWDKPAP KCEYFNKYSS CPEPIVPGGY KIRGSTPYRH GDSVTFACKT
   121  NFSMNGNKSV WCQANNMWGP TRLPTCVSVF PLECPALPMI HNGHHTSENV GSIAPGLSVT
   181  YSCESGYLLV GEKIINCLSS GKWSAVPPTC EEARCKSLGR FPNGKVKEPP ILRVGVTANF
   241  FCDEGYRLQG PPSSRCVIAG QGVAWTKMPV CEEIFCPSPP PILNGRHIGN SLANVSYGSI
   301  VTYTCDPDPE EGVNFILIGE STLRCTVDSQ KTGTWSGPAP RCELSTSAVQ CPHPQILRGR
   361  MVSGQKDRYT YNDTVIFACM FGFTLKGSKQ IRCNAQGTWE PSAPVCEKEC QAPPNILNGQ
   421  KEDRHMVRFD PGTSIKYSCN PGYVLVGEES IQCTSEGVWT PPVPQCKVAA CEATGRQLLT
   481  KPQHQFVRPD VNSSCGEGYK LSGSVYQECQ GTIPWFMEIR LCKEITCPPP PVIYNGAHTG
   541  SSLEDFPYGT TVTYTCNPGP ERGVEFSLIG ESTIRCTSND QERGTWSGPA PLCKLSLLAV
   601  QCSHVHIANG YKISGKEAPY FYNDTVTFKC YSGFTLKGSS QIRCKADNTW DPEIPVCEKE
   661  TCQHVRQSLQ ELPAGSRVEL VNTSCQDGYQ LTGHAYQMCQ DAENGIWFKK IPLCKVIHCH
   721  PPPVIVNGKH TGMMAENFLY GNEVSYECDQ GFYLLGEKKL QCRSDSKGHG SWSGPSPQCL
   781  RSPPVTRCPN PEVKHGYKLN KTHSAYSHND IVYVDCNPGF IMNGSRVIRC HTDNTWVPGV
   841  PTCIKKAFIG CPPPPKTPNG NHTGGNIARF SPGMSILYSC DQGYLLVGEA LLLCTHEGTW
   901  SQPAPHCKEV NCSSPADMDG IQKGLEPRKM YQYGAVVTLE CEDGYMLEGS PQSQCQSDHQ
   961  WNPPLAVCRS RSLAPVLCGI AAGLILLTFL IVITLYVISK HRARNYYTDT SQKEAFHLEA
  1021  REVYSVDPYN PAS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CR2 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
1
Mean surface accessibility (rSASA)
0.39
Highest tissue expression
164 nTPM

Expression across tissuesHPA

Tissue

  • lymph node: 164 nTPM
  • tonsil: 161 nTPM
  • spleen: 69 nTPM
  • appendix: 50 nTPM
  • small intestine: 16 nTPM
  • thymus: 14 nTPM

Single-cell type

  • b-cells: 57 nCPM
  • thymocytes: 14 nCPM
  • plasma cells: 9.3 nCPM
  • oocytes: 4.6 nCPM
  • early spermatids: 3.4 nCPM
  • foveolar cells: 3 nCPM

Immune cell

  • naive B-cell: 21 nTPM
  • memory B-cell: 18 nTPM
  • naive CD4 T-cell: 2.4 nTPM
  • naive CD8 T-cell: 2.2 nTPM
  • total PBMC: 1.4 nTPM
  • memory CD4 T-cell: 1 nTPM

Brain region

  • white matter: 0.7 nTPM
  • cerebral cortex: 0.6 nTPM
  • midbrain: 0.6 nTPM
  • pons: 0.4 nTPM
  • thalamus: 0.4 nTPM
  • basal ganglia: 0.3 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about CR2.

Disease | AllUniProt

Conditions CR2 is implicated in, by any mechanism.

  • Systemic lupus erythematosus 9 (SLEB9) MIM:610927
  • Immunodeficiency, common variable, 7 (CVID7) MIM:614699

Disease | GeneticClinVar

63 pathogenic / likely-pathogenic of 881 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Immunodeficiency, common variable, 7
  • CR2-related disorder
  • Systemic lupus erythematosus, susceptibility to, 9
  • Immunodeficiency, common variable, 2
  • Autosomal recessive CR2-related disorders

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)
0.88
gnomAD pLI
0
gnomAD missense Z
0.79
DepMap mean gene effect
-0.01
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% 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 CR2 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 CR2 as an antibody target. Whether an autoantibody or antibody against CR2 could matter depends on whether native CR2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CR2 is annotated at the cell surface, where native CR2 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label CR2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CR2. 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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