Seroatlas · Human Serome Atlas

PIGK

GPI-anchor transamidase

Also known as: GPI8, GPI8_HUMAN, hGPI8

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

Protein identityUniProt · HPA

UniProt accession
Q92643
Gene
PIGK
Ensembl
ENSG00000142892
Chromosome
1
Canonical length
395 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Potential drug targets, Predicted intracellular proteins, Predicted membrane proteins
Secretome location
Intracellular and membrane

OverviewNCBI Gene

This gene encodes a member of the cysteine protease family C13 that is involved in glycosylphosphatidylinositol (GPI)-anchor biosynthesis. The GPI-anchor is a glycolipid found on many blood cells and serves to anchor proteins to the cell surface. This protein is a member of the multisubunit enzyme, GPI transamidase and is thought to be its enzymatic component. GPI transamidase mediates GPI anchoring in the endoplasmic reticulum, by catalyzing the transfer of fully assembled GPI units to proteins. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

395 residues, UniProt reviewed canonical sequence.

>Q92643|PIGK
     1  MAVTDSLSRA ATVLATVLLL SFGSVAASHI EDQAEQFFRS GHTNNWAVLV CTSRFWFNYR
    61  HVANTLSVYR SVKRLGIPDS HIVLMLADDM ACNPRNPKPA TVFSHKNMEL NVYGDDVEVD
   121  YRSYEVTVEN FLRVLTGRIP PSTPRSKRLL SDDRSNILIY MTGHGGNGFL KFQDSEEITN
   181  IELADAFEQM WQKRRYNELL FIIDTCQGAS MYERFYSPNI MALASSQVGE DSLSHQPDPA
   241  IGVHLMDRYT FYVLEFLEEI NPASQTNMND LFQVCPKSLC VSTPGHRTDL FQRDPKNVLI
   301  TDFFGSVRKV EITTETIKLQ QDSEIMESSY KEDQMDEKLM EPLKYAEQLP VAQIIHQKPK
   361  LKDWHPPGGF ILGLWALIIM VFFKTYGIKH MKFIF

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PIGK 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)
0.33
Highest tissue expression
17 nTPM

Expression across tissuesHPA

Tissue

  • kidney: 17 nTPM
  • parathyroid gland: 15 nTPM
  • thyroid gland: 15 nTPM
  • heart muscle: 13 nTPM
  • liver: 12 nTPM
  • adrenal gland: 12 nTPM

Single-cell type

  • early primary spermatocytes: 119 nCPM
  • pituicytes/fscs: 90 nCPM
  • oligodendrocytes: 86 nCPM
  • retinal pigment epithelial cells: 85 nCPM
  • neutrophil progenitors: 67 nCPM
  • parietal cells: 60 nCPM

Immune cell

  • T-reg: 9.8 nTPM
  • naive CD4 T-cell: 7.5 nTPM
  • NK-cell: 7.4 nTPM
  • basophil: 7.2 nTPM
  • naive CD8 T-cell: 6.8 nTPM
  • memory CD4 T-cell: 6.1 nTPM

Brain region

  • white matter: 21 nTPM
  • cerebral cortex: 16 nTPM
  • spinal cord: 15 nTPM
  • basal ganglia: 15 nTPM
  • hypothalamus: 15 nTPM
  • cerebellum: 14 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PIGK.

Disease | AllUniProt

Conditions PIGK is implicated in, by any mechanism.

  • Neurodevelopmental disorder with hypotonia and cerebellar atrophy, with or without seizures (NEDHCAS) MIM:618879

Disease | GeneticClinVar

11 pathogenic / likely-pathogenic of 98 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Neurodevelopmental disorder with hypotonia and cerebellar atrophy, with or without seizures

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)
0.77
gnomAD pLI
0
gnomAD missense Z
0.55
DepMap mean gene effect
-0.03
DepMap dependency class
selective

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

  • GPI-anchor transamidase activity

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

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

PIGK 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 PIGK as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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