Seroatlas · Human Serome Atlas

FDCSP

Follicular dendritic cell secreted peptide

Also known as: C4orf7, FDC-SP, FDSCP_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q8NFU4
Gene
FDCSP
Ensembl
ENSG00000181617
Chromosome
4
Canonical length
85 aa
Protein class
Predicted secreted proteins
Secretome location
Secreted in other tissues

OverviewNCBI Gene

This gene encodes a small secreted protein that is expressed in follicular dendritic cells. This protein specifically binds to activated B cells, and functions as a regulator of antibody responses. It is also thought to contribute to tumor metastases by promoting cancer cell migration and invasion. [provided by RefSeq, Dec 2011]

Canonical amino-acid sequenceUniProt

85 residues, UniProt reviewed canonical sequence.

>Q8NFU4|FDCSP
     1  MKKVLLLITA ILAVAVGFPV SQDQEREKRS ISDSDELASG FFVFPYPYPF RPLPPIPFPR
    61  FPWFRRNFPI PIPESAPTTP LPSEK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against FDCSP 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
Secreted
Secreted
Yes
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.65
Highest tissue expression
7,470 nTPM

Expression across tissuesHPA

Tissue

  • salivary gland: 7,470 nTPM
  • tonsil: 3,043 nTPM
  • lymph node: 979 nTPM
  • appendix: 295 nTPM
  • breast: 170 nTPM
  • small intestine: 54 nTPM

Single-cell type

  • salivary acinar cells: 12,135 nCPM
  • submucosal glandular cells: 2,794 nCPM
  • lacrimal acinar cells: 1,256 nCPM
  • salivary myoepithelial cells: 610 nCPM
  • breast secretory cells: 259 nCPM
  • salivary basal cells: 239 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • midbrain: 1.2 nTPM
  • thalamus: 0.6 nTPM
  • choroid plexus: 0.5 nTPM
  • hypothalamus: 0.3 nTPM
  • medulla oblongata: 0.2 nTPM
  • pons: 0.1 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)
1.4
gnomAD pLI
0.08
gnomAD missense Z
-0.09
DepMap mean gene effect
0.09
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

Cellular components

Protein domainsUniProt · Pfam · InterPro

  • Follicular dendritic cell secreted peptide
  • Follicular dendritic cell secreted peptide

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

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

FDCSP is annotated as secreted, so native FDCSP circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Source-annotated serology context

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

  • This protein specifically binds to activated B cells, and functions as a regulator of antibody responses.

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