NAPSA

Napsin-A is an aspartic proteinase that is encoded in humans by the NAPSA gene.^[5] The name napsin comes from novel aspartic proteinase of the pepsin family.^[6]

NAPSA
Identifiers
Aliases	NAPSA, KAP, Kdap, NAP1, NAPA, SNAPA, napsin A aspartic peptidase
External IDs	OMIM: 605631; MGI: 109365; HomoloGene: 68418; GeneCards: NAPSA; OMA:NAPSA - orthologs
Gene location (Human) Chr. Chromosome 19 (human)[1] Band 19q13.33 Start 50,358,477 bp[1] End 50,365,830 bp[1]
Gene location (Mouse) Chr. Chromosome 7 (mouse)[2] Band 7|7 B3 Start 44,221,804 bp[2] End 44,236,286 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in lower lobe of lung upper lobe of lung upper lobe of left lung visceral pleura right lung human kidney testicle right uterine tube mucosa of transverse colon caput epididymis Top expressed in right kidney human kidney left lung right lung left lung lobe right lung lobe proximal tubule spleen granulocyte tibiofemoral joint More reference expression data BioGPS n/a
Gene ontology Molecular function endopeptidase activity hydrolase activity aspartic-type endopeptidase activity peptidase activity Cellular component extracellular region lysosome extracellular exosome alveolar lamellar body multivesicular body lumen extracellular space Biological process surfactant homeostasis protein catabolic process proteolysis membrane protein proteolysis autophagy Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 9476 16541 Ensembl ENSG00000131400 ENSMUSG00000002204 UniProt O96009 O09043 RefSeq (mRNA) NM_004851 NM_008437 RefSeq (protein) NP_004842 NP_032463 Location (UCSC) Chr 19: 50.36 – 50.37 Mb Chr 7: 44.22 – 44.24 Mb PubMed search [3] [4]
Wikidata
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The activation peptide of an aspartic proteinase acts as an inhibitor of the active site. These peptide segments, or pro-parts, are deemed important for correct folding, targeting, and control of the activation of aspartic proteinase zymogens. The pronapsin A gene is expressed predominantly in lung and kidney. Its translation product is predicted to be a fully functional, glycosylated aspartic proteinase precursor containing an RGD motif and an additional 18 residues at its C-terminus.^[5]

Utility

Detection of NAPSA gene expression can be used to distinguish adenocarcinomas from other forms of lung cancer.^[7]