Seroatlas · Human Serome Atlas

XPNPEP1

Xaa-Pro aminopeptidase 1

Also known as: XPNPEP, XPNPEPL, XPNPEPL1, XPP1_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q9NQW7
Gene
XPNPEP1
Ensembl
ENSG00000108039
Chromosome
10
Canonical length
623 aa
Protein class
Enzymes, Predicted intracellular proteins
Subcellular location
Cytosol
Quaternary structure
Homodimer

OverviewNCBI Gene

This gene encodes the cytosolic form of a metalloaminopeptidase that catalyzes the cleavage of the N-terminal amino acid adjacent to a proline residue. The gene product may play a role in degradation and maturation of tachykinins, neuropeptides, and peptide hormones. Alternative splicing results in multiple transcript variants.[provided by RefSeq, Nov 2009]

Canonical amino-acid sequenceUniProt

623 residues, UniProt reviewed canonical sequence.

>Q9NQW7|XPNPEP1
     1  MPPKVTSELL RQLRQAMRNS EYVTEPIQAY IIPSGDAHQS EYIAPCDCRR AFVSGFDGSA
    61  GTAIITEEHA AMWTDGRYFL QAAKQMDSNW TLMKMGLKDT PTQEDWLVSV LPEGSRVGVD
   121  PLIIPTDYWK KMAKVLRSAG HHLIPVKENL VDKIWTDRPE RPCKPLLTLG LDYTGISWKD
   181  KVADLRLKMA ERNVMWFVVT ALDEIAWLFN LRGSDVEHNP VFFSYAIIGL ETIMLFIDGD
   241  RIDAPSVKEH LLLDLGLEAE YRIQVHPYKS ILSELKALCA DLSPREKVWV SDKASYAVSE
   301  TIPKDHRCCM PYTPICIAKA VKNSAESEGM RRAHIKDAVA LCELFNWLEK EVPKGGVTEI
   361  SAADKAEEFR RQQADFVDLS FPTISSTGPN GAIIHYAPVP ETNRTLSLDE VYLIDSGAQY
   421  KDGTTDVTRT MHFGTPTAYE KECFTYVLKG HIAVSAAVFP TGTKGHLLDS FARSALWDSG
   481  LDYLHGTGHG VGSFLNVHEG PCGISYKTFS DEPLEAGMIV TDEPGYYEDG AFGIRIENVV
   541  LVVPVKTKYN FNNRGSLTFE PLTLVPIQTK MIDVDSLTDK ECDWLNNYHL TCRDVIGKEL
   601  QKQGRQEALE WLIRETQPIS KQH

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against XPNPEP1 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
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.22
Highest tissue expression
60 nTPM

Expression across tissuesHPA

Tissue

  • pancreas: 60 nTPM
  • small intestine: 58 nTPM
  • duodenum: 49 nTPM
  • rectum: 38 nTPM
  • colon: 30 nTPM
  • salivary gland: 29 nTPM

Single-cell type

  • platelets: 448 nCPM
  • pancreatic acinar cells: 135 nCPM
  • megakaryocytes: 111 nCPM
  • enterocytes: 100 nCPM
  • goblet cells: 81 nCPM
  • foveolar cells: 62 nCPM

Immune cell

  • myeloid DC: 46 nTPM
  • intermediate monocyte: 42 nTPM
  • non-classical monocyte: 37 nTPM
  • plasmacytoid DC: 36 nTPM
  • NK-cell: 31 nTPM
  • total PBMC: 30 nTPM

Brain region

  • choroid plexus: 22 nTPM
  • hippocampal formation: 17 nTPM
  • white matter: 14 nTPM
  • cerebral cortex: 14 nTPM
  • thalamus: 14 nTPM
  • hypothalamus: 14 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)
0.4
gnomAD pLI
0.33
gnomAD missense Z
2.42
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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads XPNPEP1 as an antibody target. Whether an autoantibody or antibody against XPNPEP1 could matter depends on whether native XPNPEP1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

XPNPEP1 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 XPNPEP1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/XPNPEP1. 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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