Seroatlas · Human Serome Atlas

PIGA

Phosphatidylinositol N-acetylglucosaminyltransferase subunit A

Also known as: GPI3, PIG-A, PIGA_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P37287
Gene
PIGA
Ensembl
ENSG00000165195
Chromosome
X
Canonical length
484 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Potential drug targets, Predicted intracellular proteins, Predicted membrane proteins

OverviewNCBI Gene

This gene encodes a protein required for synthesis of N-acetylglucosaminyl phosphatidylinositol (GlcNAc-PI), the first intermediate in the biosynthetic pathway of GPI anchor. The GPI anchor is a glycolipid found on many blood cells and which serves to anchor proteins to the cell surface. Paroxysmal nocturnal hemoglobinuria, an acquired hematologic disorder, has been shown to result from mutations in this gene. Alternate splice variants have been characterized. A related pseudogene is located on chromosome 12. [provided by RefSeq, Jun 2010]

Canonical amino-acid sequenceUniProt

484 residues, UniProt reviewed canonical sequence.

>P37287|PIGA
     1  MACRGGAGNG HRASATLSRV SPGSLYTCRT RTHNICMVSD FFYPNMGGVE SHIYQLSQCL
    61  IERGHKVIIV THAYGNRKGI RYLTSGLKVY YLPLKVMYNQ STATTLFHSL PLLRYIFVRE
   121  RVTIIHSHSS FSAMAHDALF HAKTMGLQTV FTDHSLFGFA DVSSVLTNKL LTVSLCDTNH
   181  IICVSYTSKE NTVLRAALNP EIVSVIPNAV DPTDFTPDPF RRHDSITIVV VSRLVYRKGI
   241  DLLSGIIPEL CQKYPDLNFI IGGEGPKRII LEEVRERYQL HDRVRLLGAL EHKDVRNVLV
   301  QGHIFLNTSL TEAFCMAIVE AASCGLQVVS TRVGGIPEVL PENLIILCEP SVKSLCEGLE
   361  KAIFQLKSGT LPAPENIHNI VKTFYTWRNV AERTEKVYDR VSVEAVLPMD KRLDRLISHC
   421  GPVTGYIFAL LAVFNFLFLI FLRWMTPDSI IDVAIDATGP RGAWTNNYSH SKRGGENNEI
   481  SETR

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PIGA 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
Other membrane
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.27
Highest tissue expression
9.6 nTPM

Expression across tissuesHPA

Tissue

  • urinary bladder: 9.6 nTPM
  • bone marrow: 8.8 nTPM
  • lung: 6.3 nTPM
  • esophagus: 4.8 nTPM
  • tonsil: 4.4 nTPM
  • salivary gland: 4.3 nTPM

Single-cell type

  • alveolar cells type 2: 142 nCPM
  • urothelial cells: 121 nCPM
  • transitional alveolar cells: 114 nCPM
  • endometrial glandular cells: 100 nCPM
  • esophageal suprabasal cells: 93 nCPM
  • esophageal apical cells: 81 nCPM

Immune cell

  • basophil: 23 nTPM
  • non-classical monocyte: 9.2 nTPM
  • intermediate monocyte: 6.4 nTPM
  • neutrophil: 5.5 nTPM
  • eosinophil: 4.4 nTPM
  • memory CD4 T-cell: 4.3 nTPM

Brain region

  • white matter: 13 nTPM
  • cerebral cortex: 7.6 nTPM
  • medulla oblongata: 7.5 nTPM
  • basal ganglia: 7.1 nTPM
  • midbrain: 7 nTPM
  • thalamus: 6.6 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PIGA.

Disease | AllUniProt

Conditions PIGA is implicated in, by any mechanism.

  • Paroxysmal nocturnal hemoglobinuria 1 (PNH1) MIM:300818
  • Multiple congenital anomalies-hypotonia-seizures syndrome 2 (MCAHS2) MIM:300868
  • Neurodevelopmental disorder with epilepsy and hemochromatosis (NEDEPH) MIM:301072

Disease | GeneticClinVar

48 pathogenic / likely-pathogenic of 481 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)
0.3
gnomAD pLI
0.96
gnomAD missense Z
2.17
DepMap mean gene effect
0.03
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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 PIGA 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 PIGA as an antibody target. Whether an autoantibody or antibody against PIGA could matter depends on whether native PIGA is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PIGA is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label PIGA as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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