Seroatlas · Human Serome Atlas

GPC4

Glypican-4

Also known as: GPC4_HUMAN, K-glypican

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

Protein identityUniProt · HPA

UniProt accession
O75487
Gene
GPC4
Ensembl
ENSG00000076716
Chromosome
X
Canonical length
556 aa
Protein class
Disease related genes, Human disease related genes, Plasma proteins, Predicted membrane proteins
Subcellular location
Nucleoplasm,Plasma membrane
Secretome location
Intracellular and 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 GPC4 gene is adjacent to the 3' end of GPC3 and may also play a role in Simpson-Golabi-Behmel syndrome. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

556 residues, UniProt reviewed canonical sequence.

>O75487|GPC4
     1  MARFGLPALL CTLAVLSAAL LAAELKSKSC SEVRRLYVSK GFNKNDAPLH EINGDHLKIC
    61  PQGSTCCSQE MEEKYSLQSK DDFKSVVSEQ CNHLQAVFAS RYKKFDEFFK ELLENAEKSL
   121  NDMFVKTYGH LYMQNSELFK DLFVELKRYY VVGNVNLEEM LNDFWARLLE RMFRLVNSQY
   181  HFTDEYLECV SKYTEQLKPF GDVPRKLKLQ VTRAFVAART FAQGLAVAGD VVSKVSVVNP
   241  TAQCTHALLK MIYCSHCRGL VTVKPCYNYC SNIMRGCLAN QGDLDFEWNN FIDAMLMVAE
   301  RLEGPFNIES VMDPIDVKIS DAIMNMQDNS VQVSQKVFQG CGPPKPLPAG RISRSISESA
   361  FSARFRPHHP EERPTTAAGT SLDRLVTDVK EKLKQAKKFW SSLPSNVCND ERMAAGNGNE
   421  DDCWNGKGKS RYLFAVTGNG LANQGNNPEV QVDTSKPDIL ILRQIMALRV MTSKMKNAYN
   481  GNDVDFFDIS DESSGEGSGS GCEYQQCPSE FDYNATDHAG KSANEKADSA GVRPGAQAYL
   541  LTVFCILFLV MQREWR

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against GPC4 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)
0.34
Highest tissue expression
27 nTPM

Expression across tissuesHPA

Tissue

  • placenta: 27 nTPM
  • blood vessel: 27 nTPM
  • skeletal muscle: 23 nTPM
  • colon: 21 nTPM
  • kidney: 19 nTPM
  • tongue: 19 nTPM

Single-cell type

  • gonadotrophs: 349 nCPM
  • proximal tubule cells: 156 nCPM
  • pituitary stem cells: 137 nCPM
  • ependymal cells: 103 nCPM
  • alveolar cells type 2: 90 nCPM
  • loop of henle epithelial cells: 84 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

  • white matter: 15 nTPM
  • hypothalamus: 13 nTPM
  • medulla oblongata: 13 nTPM
  • midbrain: 12 nTPM
  • spinal cord: 11 nTPM
  • basal ganglia: 11 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about GPC4.

Disease | AllUniProt

Conditions GPC4 is implicated in, by any mechanism.

Disease | GeneticClinVar

16 pathogenic / likely-pathogenic of 241 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.37
gnomAD pLI
0.93
gnomAD missense Z
1.66
DepMap mean gene effect
0.19
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

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of GPC4 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 GPC4 as an antibody target. Whether an autoantibody or antibody against GPC4 could matter depends on whether native GPC4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

GPC4 is annotated at the cell surface, where native GPC4 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 GPC4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/GPC4. 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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