Seroatlas · Human Serome Atlas

FCMR

Immunoglobulin mu Fc receptor

Also known as: FAIM3, FCMR_HUMAN, FcmuR, TOSO

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

Protein identityUniProt · HPA

UniProt accession
O60667
Gene
FCMR
Ensembl
ENSG00000162894
Chromosome
1
Canonical length
390 aa
Protein class
Predicted intracellular proteins, Predicted membrane proteins, Predicted secreted proteins
Subcellular location
Nucleoplasm,Golgi apparatus,Plasma membrane,Centrosome
Secretome location
Secreted to blood

OverviewNCBI Gene

Fc receptors specifically bind to the Fc region of immunoglobulins (Igs) to mediate the unique functions of each Ig class. FAIM3 encodes an Fc receptor for IgM (see MIM 147020) (Kubagawa et al., 2009 [PubMed 19858324]; Shima et al., 2010 [PubMed 20042454]).[supplied by OMIM, Jul 2010]

Canonical amino-acid sequenceUniProt

390 residues, UniProt reviewed canonical sequence.

>O60667|FCMR
     1  MDFWLWPLYF LPVSGALRIL PEVKVEGELG GSVTIKCPLP EMHVRIYLCR EMAGSGTCGT
    61  VVSTTNFIKA EYKGRVTLKQ YPRKNLFLVE VTQLTESDSG VYACGAGMNT DRGKTQKVTL
   121  NVHSEYEPSW EEQPMPETPK WFHLPYLFQM PAYASSSKFV TRVTTPAQRG KVPPVHHSSP
   181  TTQITHRPRV SRASSVAGDK PRTFLPSTTA SKISALEGLL KPQTPSYNHH TRLHRQRALD
   241  YGSQSGREGQ GFHILIPTIL GLFLLALLGL VVKRAVERRK ALSRRARRLA VRMRALESSQ
   301  RPRGSPRPRS QNNIYSACPR RARGADAAGT GEAPVPGPGA PLPPAPLQVS ESPWLHAPSL
   361  KTSCEYVSLY HQPAAMMEDS DSDDYINVPA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against FCMR 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)
0.58
Highest tissue expression
169 nTPM

Expression across tissuesHPA

Tissue

  • tonsil: 169 nTPM
  • lymph node: 142 nTPM
  • spleen: 108 nTPM
  • thymus: 72 nTPM
  • appendix: 71 nTPM
  • small intestine: 56 nTPM

Single-cell type

  • b-cells: 297 nCPM
  • nk-cells: 108 nCPM
  • t-cells: 100 nCPM
  • epicardial cells: 91 nCPM
  • thymocytes: 62 nCPM
  • innate lymphoid cells: 42 nCPM

Immune cell

  • naive B-cell: 1,062 nTPM
  • memory B-cell: 886 nTPM
  • T-reg: 690 nTPM
  • naive CD4 T-cell: 485 nTPM
  • total PBMC: 417 nTPM
  • naive CD8 T-cell: 337 nTPM

Brain region

  • white matter: 2.5 nTPM
  • thalamus: 2.3 nTPM
  • choroid plexus: 2.2 nTPM
  • medulla oblongata: 2.2 nTPM
  • hypothalamus: 2.1 nTPM
  • basal ganglia: 2 nTPM

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)
1.03
gnomAD pLI
0
DepMap mean gene effect
-0.08
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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

Antibody and autoantibody relevanceSeroatlas analysis

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

FCMR is annotated at the cell surface, where native FCMR 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 FCMR as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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