XPNPEP1 Gene

HGNC Family	Aminopeptidases
Name	X-prolyl aminopeptidase (aminopeptidase P) 1, soluble
Description	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]
Summary	{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nXPNPEP1 is implicated in the metabolism of inflammatory mediators, as illustrated by a genome‐wide association study in biliary atresia where the strongest disease association was found at a variant located downstream of XPNPEP1. This finding suggests that the gene’s product may modulate the degradation of peptides that are critical for managing the inflammatory process in the liver. Moreover, genetic predisposition affecting peptide metabolism has also been proposed to contribute to adverse drug reactions, such as the persistent cough observed in patients on angiotensin‐converting enzyme inhibitors, thereby linking XPNPEP1 to a broader inflammatory context."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n \n"}, {"type": "p", "children": [{"type": "t", "text": "\nAs a member of the enzyme system involved in the renin–angiotensin and kinin hormonal pathways, XPNPEP1—or its enzymatically similar counterparts—plays a key role in the degradation of the potent vasodilator bradykinin. This function is critical in controlling blood pressure and vascular tone, hinting at its possible involvement in conditions such as oral contraceptive pill–induced hypertension. By modulating levels of inflammatory and vasoactive peptides, XPNPEP1 represents an important checkpoint in maintaining cardiovascular homeostasis."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n \n"}, {"type": "p", "children": [{"type": "t", "text": "\nDetailed biochemical analyses have shed light on the catalytic mechanism of aminopeptidase P enzymes, underscoring their specificity for Xaa-Pro dipeptides. In particular, studies have demonstrated that certain residues—for example, arginine 535—are essential not only for the catalytic turnover of substrates like bradykinin but also for stabilizing the enzyme’s dimeric, functionally active form. These insights reinforce the concept that XPNPEP1’s enzymatic activity is finely tuned to control inflammatory and vasoactive peptide levels, further validating its importance in both liver pathology and systemic vascular regulation."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}]}, {"type": "t", "text": ""}]}]}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Maria-Mercè Garcia-Barceló, Ming-Yiu Yeung, Xiao-Ping Miao, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Genome-wide association study identifies a susceptibility locus for biliary atresia on 10q24.2."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Hum Mol Genet (2010)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1093/hmg/ddq196"}], "href": "https://doi.org/10.1093/hmg/ddq196"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "20460270"}], "href": "https://pubmed.ncbi.nlm.nih.gov/20460270"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Antonio Grilo, María P Sáez-Rosas, Juan Santos-Morano, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Identification of genetic factors associated with susceptibility to angiotensin-converting enzyme inhibitors-induced cough."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Pharmacogenet Genomics (2011)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1097/FPC.0b013e328341041c"}], "href": "https://doi.org/10.1097/FPC.0b013e328341041c"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "21052031"}], "href": "https://pubmed.ncbi.nlm.nih.gov/21052031"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Amy L Cilia La Corte, Angela M Carter, Anthony J Turner, et al. "}, {"type": "b", "children": [{"type": "t", "text": "The bradykinin-degrading aminopeptidase P is increased in women taking the oral contraceptive pill."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Renin Angiotensin Aldosterone Syst (2008)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1177/1470320308096405"}], "href": "https://doi.org/10.1177/1470320308096405"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19126663"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19126663"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Hui-Chuan Chang, Camy C-H Kung, Tzu-Ting Chang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Investigation of the proton relay system operative in human cystosolic aminopeptidase P."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2018)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0190816"}], "href": "https://doi.org/10.1371/journal.pone.0190816"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "29351301"}], "href": "https://pubmed.ncbi.nlm.nih.gov/29351301"}]}]}]}
Synonyms	XPNPEPL, SAMP, XPNPEP, XPNPEPL1, APP1
Proteins	XPP1_HUMAN
NCBI Gene ID	7511
API
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Predicted Functions
Co-expressed Genes
Expression in Tissues and Cell Lines

Functional Associations

XPNPEP1 has 6,982 functional associations with biological entities spanning 8 categories (molecular profile, organism, chemical, functional term, phrase or reference, disease, phenotype or trait, structural feature, cell line, cell type or tissue, gene, protein or microRNA) extracted from 113 datasets.

Click the + buttons to view associations for XPNPEP1 from the datasets below.

If available, associations are ranked by standardized value

Harmonizome 3.0

XPNPEP1 Gene

Functional Associations

Please acknowledge the Harmonizome in your publications by citing the following reference(s):

	Dataset	Summary
	Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles	tissues with high or low expression of XPNPEP1 gene relative to other tissues from the Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles dataset.
	Allen Brain Atlas Adult Mouse Brain Tissue Gene Expression Profiles	tissues with high or low expression of XPNPEP1 gene relative to other tissues from the Allen Brain Atlas Adult Mouse Brain Tissue Gene Expression Profiles dataset.
	Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles	tissue samples with high or low expression of XPNPEP1 gene relative to other tissue samples from the Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles dataset.
	Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by Microarray	tissue samples with high or low expression of XPNPEP1 gene relative to other tissue samples from the Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by Microarray dataset.
	Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by RNA-seq	tissue samples with high or low expression of XPNPEP1 gene relative to other tissue samples from the Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by RNA-seq dataset.
	Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles	tissues with high or low expression of XPNPEP1 gene relative to other tissues from the Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles dataset.
	BioGPS Cell Line Gene Expression Profiles	cell lines with high or low expression of XPNPEP1 gene relative to other cell lines from the BioGPS Cell Line Gene Expression Profiles dataset.
	BioGPS Human Cell Type and Tissue Gene Expression Profiles	cell types and tissues with high or low expression of XPNPEP1 gene relative to other cell types and tissues from the BioGPS Human Cell Type and Tissue Gene Expression Profiles dataset.
	BioGPS Mouse Cell Type and Tissue Gene Expression Profiles	cell types and tissues with high or low expression of XPNPEP1 gene relative to other cell types and tissues from the BioGPS Mouse Cell Type and Tissue Gene Expression Profiles dataset.
	Carcinogenome Chemical Perturbation Carcinogenicity Signatures	small molecule perturbations changing expression of XPNPEP1 gene from the Carcinogenome Chemical Perturbation Carcinogenicity Signatures dataset.
	CCLE Cell Line Gene CNV Profiles	cell lines with high or low copy number of XPNPEP1 gene relative to other cell lines from the CCLE Cell Line Gene CNV Profiles dataset.
	CCLE Cell Line Gene Expression Profiles	cell lines with high or low expression of XPNPEP1 gene relative to other cell lines from the CCLE Cell Line Gene Expression Profiles dataset.
	CCLE Cell Line Proteomics	Cell lines associated with XPNPEP1 protein from the CCLE Cell Line Proteomics dataset.
	CellMarker Gene-Cell Type Associations	cell types associated with XPNPEP1 gene from the CellMarker Gene-Cell Type Associations dataset.
	ChEA Transcription Factor Binding Site Profiles	transcription factor binding site profiles with transcription factor binding evidence at the promoter of XPNPEP1 gene from the CHEA Transcription Factor Binding Site Profiles dataset.
	ChEA Transcription Factor Targets	transcription factors binding the promoter of XPNPEP1 gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets dataset.
	ChEA Transcription Factor Targets 2022	transcription factors binding the promoter of XPNPEP1 gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets 2022 dataset.
	CM4AI U2OS Cell Map Protein Localization Assemblies	assemblies containing XPNPEP1 protein from integrated AP-MS and IF data from the CM4AI U2OS Cell Map Protein Localization Assemblies dataset.
	CMAP Signatures of Differentially Expressed Genes for Small Molecules	small molecule perturbations changing expression of XPNPEP1 gene from the CMAP Signatures of Differentially Expressed Genes for Small Molecules dataset.
	COMPARTMENTS Curated Protein Localization Evidence Scores	cellular components containing XPNPEP1 protein from the COMPARTMENTS Curated Protein Localization Evidence Scores dataset.
	COMPARTMENTS Curated Protein Localization Evidence Scores 2025	cellular components containing XPNPEP1 protein from the COMPARTMENTS Curated Protein Localization Evidence Scores 2025 dataset.
	COMPARTMENTS Experimental Protein Localization Evidence Scores	cellular components containing XPNPEP1 protein in low- or high-throughput protein localization assays from the COMPARTMENTS Experimental Protein Localization Evidence Scores dataset.
	COMPARTMENTS Experimental Protein Localization Evidence Scores 2025	cellular components containing XPNPEP1 protein in low- or high-throughput protein localization assays from the COMPARTMENTS Experimental Protein Localization Evidence Scores 2025 dataset.
	COMPARTMENTS Text-mining Protein Localization Evidence Scores	cellular components co-occuring with XPNPEP1 protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores dataset.
	COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025	cellular components co-occuring with XPNPEP1 protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 dataset.
	COSMIC Cell Line Gene CNV Profiles	cell lines with high or low copy number of XPNPEP1 gene relative to other cell lines from the COSMIC Cell Line Gene CNV Profiles dataset.
	COSMIC Cell Line Gene Mutation Profiles	cell lines with XPNPEP1 gene mutations from the COSMIC Cell Line Gene Mutation Profiles dataset.
	CTD Gene-Chemical Interactions	chemicals interacting with XPNPEP1 gene/protein from the curated CTD Gene-Chemical Interactions dataset.
	CTD Gene-Disease Associations	diseases associated with XPNPEP1 gene/protein from the curated CTD Gene-Disease Associations dataset.
	DepMap CRISPR Gene Dependency	cell lines with fitness changed by XPNPEP1 gene knockdown relative to other cell lines from the DepMap CRISPR Gene Dependency dataset.
	DISEASES Text-mining Gene-Disease Association Evidence Scores	diseases co-occuring with XPNPEP1 gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores dataset.
	DISEASES Text-mining Gene-Disease Association Evidence Scores 2025	diseases co-occuring with XPNPEP1 gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores 2025 dataset.
	DisGeNET Gene-Disease Associations	diseases associated with XPNPEP1 gene in GWAS and other genetic association datasets from the DisGeNET Gene-Disease Associations dataset.
	DisGeNET Gene-Phenotype Associations	phenotypes associated with XPNPEP1 gene in GWAS and other genetic association datasets from the DisGeNET Gene-Phenoptype Associations dataset.
	ENCODE Histone Modification Site Profiles	histone modification site profiles with high histone modification abundance at XPNPEP1 gene from the ENCODE Histone Modification Site Profiles dataset.
	ENCODE Transcription Factor Binding Site Profiles	transcription factor binding site profiles with transcription factor binding evidence at the promoter of XPNPEP1 gene from the ENCODE Transcription Factor Binding Site Profiles dataset.
	ENCODE Transcription Factor Targets	transcription factors binding the promoter of XPNPEP1 gene in ChIP-seq datasets from the ENCODE Transcription Factor Targets dataset.
	ESCAPE Omics Signatures of Genes and Proteins for Stem Cells	PubMedIDs of publications reporting gene signatures containing XPNPEP1 from the ESCAPE Omics Signatures of Genes and Proteins for Stem Cells dataset.
	GAD Gene-Disease Associations	diseases associated with XPNPEP1 gene in GWAS and other genetic association datasets from the GAD Gene-Disease Associations dataset.
	GAD High Level Gene-Disease Associations	diseases associated with XPNPEP1 gene in GWAS and other genetic association datasets from the GAD High Level Gene-Disease Associations dataset.