Seroatlas · Human Serome Atlas

GPC3

Glypican-3

Also known as: DGSX, GPC3_HUMAN, OCI-5, SDYS, SGB, SGBS, SGBS1

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

Protein identityUniProt · HPA

UniProt accession
P51654
Gene
GPC3
Ensembl
ENSG00000147257
Chromosome
X
Canonical length
580 aa
Protein class
Cancer-related genes, Disease related genes, Human disease related genes, Predicted membrane proteins
Subcellular location
Plasma membrane

OverviewNCBI Gene

Cell surface heparan sulfate proteoglycans are composed of a membrane-associated protein core substituted with a variable number of heparan sulfate chains. Members of the glypican-related integral membrane proteoglycan family (GRIPS) contain a core protein anchored to the cytoplasmic membrane via a glycosyl phosphatidylinositol linkage. These proteins may play a role in the control of cell division and growth regulation. The protein encoded by this gene can bind to and inhibit the dipeptidyl peptidase activity of CD26, and it can induce apoptosis in certain cell types. Deletion mutations in this gene are associated with Simpson-Golabi-Behmel syndrome, also known as Simpson dysmorphia syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2009]

Canonical amino-acid sequenceUniProt

580 residues, UniProt reviewed canonical sequence.

>P51654|GPC3
     1  MAGTVRTACL VVAMLLSLDF PGQAQPPPPP PDATCHQVRS FFQRLQPGLK WVPETPVPGS
    61  DLQVCLPKGP TCCSRKMEEK YQLTARLNME QLLQSASMEL KFLIIQNAAV FQEAFEIVVR
   121  HAKNYTNAMF KNNYPSLTPQ AFEFVGEFFT DVSLYILGSD INVDDMVNEL FDSLFPVIYT
   181  QLMNPGLPDS ALDINECLRG ARRDLKVFGN FPKLIMTQVS KSLQVTRIFL QALNLGIEVI
   241  NTTDHLKFSK DCGRMLTRMW YCSYCQGLMM VKPCGGYCNV VMQGCMAGVV EIDKYWREYI
   301  LSLEELVNGM YRIYDMENVL LGLFSTIHDS IQYVQKNAGK LTTTIGKLCA HSQQRQYRSA
   361  YYPEDLFIDK KVLKVAHVEH EETLSSRRRE LIQKLKSFIS FYSALPGYIC SHSPVAENDT
   421  LCWNGQELVE RYSQKAARNG MKNQFNLHEL KMKGPEPVVS QIIDKLKHIN QLLRTMSMPK
   481  GRVLDKNLDE EGFESGDCGD DEDECIGGSG DGMIKVKNQL RFLAELAYDL DVDDAPGNSQ
   541  QATPKDNEIS TFHNLGNVHS PLKLLTSMAI SVVCFFFLVH

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against GPC3 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)
0.38
Highest tissue expression
670 nTPM

Expression across tissuesHPA

Tissue

  • placenta: 670 nTPM
  • lung: 141 nTPM
  • adipose tissue: 111 nTPM
  • kidney: 109 nTPM
  • breast: 68 nTPM
  • epididymis: 68 nTPM

Single-cell type

  • pituitary stem cells: 799 nCPM
  • fibroblasts: 327 nCPM
  • syncytiotrophoblasts: 230 nCPM
  • pituicytes/fscs: 225 nCPM
  • respiratory ciliated cells: 196 nCPM
  • fibro-adipogenic progenitors: 163 nCPM

Immune cell

  • naive CD4 T-cell: 1.9 nTPM
  • naive CD8 T-cell: 1.2 nTPM
  • NK-cell: 0.8 nTPM
  • memory CD4 T-cell: 0.2 nTPM
  • total PBMC: 0.2 nTPM
  • basophil: 0.1 nTPM

Brain region

  • hypothalamus: 9.1 nTPM
  • midbrain: 7.9 nTPM
  • pons: 7.3 nTPM
  • medulla oblongata: 5.6 nTPM
  • spinal cord: 4.7 nTPM
  • white matter: 4.1 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about GPC3.

Disease | AllUniProt

Conditions GPC3 is implicated in, by any mechanism.

  • Simpson-Golabi-Behmel syndrome 1 (SGBS1) MIM:312870

Disease | GeneticClinVar

70 pathogenic / likely-pathogenic of 1,086 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Disease | ImmuneIEDB

Conditions an epitope on GPC3 was assayed in.

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)
0.16
gnomAD pLI
1
gnomAD missense Z
1.45
DepMap mean gene effect
0.17
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

  • peptidyl-dipeptidase inhibitor activity

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of GPC3 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 GPC3 as an antibody target. Whether an autoantibody or antibody against GPC3 could matter depends on whether native GPC3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

GPC3 is annotated at the cell surface, where native GPC3 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 GPC3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/GPC3. 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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