Seroatlas · Human Serome Atlas

SLPI

Antileukoproteinase

Also known as: ALK1, ALP, BLPI, HUSI, HUSI-I, SLPI_HUMAN, WAP4, WFDC4

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

Protein identityUniProt · HPA

UniProt accession
P03973
Gene
SLPI
Ensembl
ENSG00000124107
Chromosome
20
Canonical length
132 aa
Protein class
Cancer-related genes, Plasma proteins, Predicted secreted proteins
Subcellular location
Golgi apparatus
Secretome location
Secreted to blood

OverviewNCBI Gene

This gene encodes a secreted inhibitor which protects epithelial tissues from serine proteases. It is found in various secretions including seminal plasma, cervical mucus, and bronchial secretions, and has affinity for trypsin, leukocyte elastase, and cathepsin G. Its inhibitory effect contributes to the immune response by protecting epithelial surfaces from attack by endogenous proteolytic enzymes. This antimicrobial protein has antibacterial, antifungal and antiviral activity. [provided by RefSeq, Nov 2014]

Canonical amino-acid sequenceUniProt

132 residues, UniProt reviewed canonical sequence.

>P03973|SLPI
     1  MKSSGLFPFL VLLALGTLAP WAVEGSGKSF KAGVCPPKKS AQCLRYKKPE CQSDWQCPGK
    61  KRCCPDTCGI KCLDPVDTPN PTRRKPGKCP VTYGQCLMLN PPNFCEMDGQ CKRDLKCCMG
   121  MCGKSCVSPV KA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SLPI 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)
0.45
Highest tissue expression
26,260 nTPM

Expression across tissuesHPA

Tissue

  • cervix: 26,260 nTPM
  • salivary gland: 14,072 nTPM
  • seminal vesicle: 2,779 nTPM
  • esophagus: 1,355 nTPM
  • lung: 1,112 nTPM
  • vagina: 687 nTPM

Single-cell type

  • submucosal glandular cells: 31,818 nCPM
  • respiratory secretory cells: 25,615 nCPM
  • esophageal apical cells: 20,422 nCPM
  • endometrial secretory cells: 16,782 nCPM
  • conjunctival goblet cells: 12,809 nCPM
  • respiratory deuterosomal cells: 12,518 nCPM

Immune cell

  • neutrophil: 324 nTPM
  • total PBMC: 7.9 nTPM
  • non-classical monocyte: 4 nTPM
  • basophil: 3.6 nTPM
  • intermediate monocyte: 3.3 nTPM
  • classical monocyte: 0.9 nTPM

Brain region

  • choroid plexus: 50 nTPM
  • thalamus: 14 nTPM
  • cerebral cortex: 4.8 nTPM
  • medulla oblongata: 4.1 nTPM
  • midbrain: 4 nTPM
  • pons: 3.9 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SLPI.

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 27 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)
1.61
gnomAD pLI
0
gnomAD missense Z
0.04
DepMap mean gene effect
0.03
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 SLPI 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 SLPI as an antibody target. Whether an autoantibody or antibody against SLPI could matter depends on whether native SLPI is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SLPI is annotated as secreted, so native SLPI 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 SLPI as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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