Seroatlas · Human Serome Atlas

PI3

Elafin

Also known as: cementoin, ELAF_HUMAN, ELAFIN, ESI, SKALP, WAP3, WFDC14

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

Protein identityUniProt · HPA

UniProt accession
P19957
Gene
PI3
Ensembl
ENSG00000124102
Chromosome
20
Canonical length
117 aa
Protein class
Plasma proteins, Predicted secreted proteins
Subcellular location
Plasma membrane
Secretome location
Secreted to blood

OverviewNCBI Gene

This gene encodes an elastase-specific inhibitor that functions as an antimicrobial peptide against Gram-positive and Gram-negative bacteria, and fungal pathogens. The protein contains a WAP-type four-disulfide core (WFDC) domain, and is thus a member of the WFDC domain family. Most WFDC gene members are localized to chromosome 20q12-q13 in two clusters: centromeric and telomeric. This gene belongs to the centromeric cluster. Expression of this gene is upgulated by bacterial lipopolysaccharides and cytokines. [provided by RefSeq, Oct 2014]

Canonical amino-acid sequenceUniProt

117 residues, UniProt reviewed canonical sequence.

>P19957|PI3
     1  MRASSFLIVV VFLIAGTLVL EAAVTGVPVK GQDTVKGRVP FNGQDPVKGQ VSVKGQDKVK
    61  AQEPVKGPVS TKPGSCPIIL IRCAMLNPPN RCLKDTDCPG IKKCCEGSCG MACFVPQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PI3 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)
0.57
Highest tissue expression
2,188 nTPM

Expression across tissuesHPA

Tissue

  • esophagus: 2,188 nTPM
  • tonsil: 1,968 nTPM
  • vagina: 1,669 nTPM
  • cervix: 1,451 nTPM
  • salivary gland: 529 nTPM
  • colon: 119 nTPM

Single-cell type

  • esophageal apical cells: 14,978 nCPM
  • gastric progenitor cells: 2,757 nCPM
  • esophageal suprabasal cells: 1,656 nCPM
  • endometrial secretory cells: 696 nCPM
  • suprabasal keratinocytes: 361 nCPM
  • colonocytes: 187 nCPM

Immune cell

  • neutrophil: 1,775 nTPM
  • eosinophil: 1.7 nTPM
  • total PBMC: 0.6 nTPM
  • classical monocyte: 0.4 nTPM
  • basophil: 0.3 nTPM
  • intermediate monocyte: 0.3 nTPM

Brain region

  • thalamus: 40 nTPM
  • cerebral cortex: 25 nTPM
  • pons: 15 nTPM
  • choroid plexus: 2.1 nTPM
  • basal ganglia: 0.7 nTPM
  • hypothalamus: 0.3 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)
1.66
gnomAD pLI
0.17
gnomAD missense Z
0.1
DepMap mean gene effect
0.13
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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PI3 as an antibody target. Whether an autoantibody or antibody against PI3 could matter depends on whether native PI3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PI3 is annotated as secreted, so native PI3 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.

Annotation status

The present source text does not explicitly label PI3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PI3. 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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