Seroatlas · Human Serome Atlas

FCGR2B

Low affinity immunoglobulin gamma Fc region receptor II-b

Also known as: CD32, CD32B, FCG2, FCG2B_HUMAN, FcgammaRIIb, FCGR2, FcGRIIB

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

Protein identityUniProt · HPA

UniProt accession
P31994
Gene
FCGR2B
Ensembl
ENSG00000072694
Chromosome
1
Canonical length
310 aa
Protein class
Cancer-related genes, CD markers, Disease related genes, FDA approved drug targets, Human disease related genes, Predicted membrane proteins

OverviewNCBI Gene

The protein encoded by this gene is a low affinity receptor for the Fc region of immunoglobulin gamma complexes. The encoded protein is involved in the phagocytosis of immune complexes and in the regulation of antibody production by B-cells. Variations in this gene may increase susceptibilty to systemic lupus erythematosus (SLE). Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2010]

Canonical amino-acid sequenceUniProt

310 residues, UniProt reviewed canonical sequence.

>P31994|FCGR2B
     1  MGILSFLPVL ATESDWADCK SPQPWGHMLL WTAVLFLAPV AGTPAAPPKA VLKLEPQWIN
    61  VLQEDSVTLT CRGTHSPESD SIQWFHNGNL IPTHTQPSYR FKANNNDSGE YTCQTGQTSL
   121  SDPVHLTVLS EWLVLQTPHL EFQEGETIVL RCHSWKDKPL VKVTFFQNGK SKKFSRSDPN
   181  FSIPQANHSH SGDYHCTGNI GYTLYSSKPV TITVQAPSSS PMGIIVAVVT GIAVAAIVAA
   241  VVALIYCRKK RISALPGYPE CREMGETLPE KPANPTNPDE ADKVGAENTI TYSLLMHPDA
   301  LEEPDDQNRI

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against FCGR2B 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)
0.45
Highest tissue expression
378 nTPM

Expression across tissuesHPA

Tissue

  • placenta: 378 nTPM
  • liver: 40 nTPM
  • adipose tissue: 29 nTPM
  • tonsil: 28 nTPM
  • spleen: 25 nTPM
  • lung: 21 nTPM

Single-cell type

  • cdc: 237 nCPM
  • macrophages: 117 nCPM
  • plasma cells: 72 nCPM
  • b-cells: 56 nCPM
  • vascular endothelial cells: 49 nCPM
  • monocytes: 40 nCPM

Immune cell

  • basophil: 329 nTPM
  • memory B-cell: 204 nTPM
  • naive B-cell: 161 nTPM
  • myeloid DC: 73 nTPM
  • neutrophil: 54 nTPM
  • eosinophil: 27 nTPM

Brain region

  • white matter: 12 nTPM
  • medulla oblongata: 9.1 nTPM
  • choroid plexus: 8.5 nTPM
  • spinal cord: 4.2 nTPM
  • pons: 3.1 nTPM
  • thalamus: 2.6 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about FCGR2B.

Disease | AllUniProt

Conditions FCGR2B is implicated in, by any mechanism.

Disease | AutoantibodyPubMed

Conditions in which antibodies against FCGR2B are reported. Each links to that disease's full target list.

ReferencesPubMed · IEDB

Publications for FCGR2B 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

6 publications

Show 1 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. 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)
0.63
gnomAD pLI
0.46
gnomAD missense Z
0.11
DepMap mean gene effect
-0.21
DepMap dependency class
selective

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 FCGR2B 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 FCGR2B as an antibody target. Whether an autoantibody or antibody against FCGR2B could matter depends on whether native FCGR2B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

FCGR2B is annotated at the cell surface, where native FCGR2B 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.

  • The encoded protein is involved in the phagocytosis of immune complexes and in the regulation of antibody production by B-cells.

Canonical record: https://seroatlas.com/gene/FCGR2B. 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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