Seroatlas · Human Serome Atlas

NAPSA

Napsin-A

Also known as: KAP, Kdap, NAP1, NAPA, NAPSA_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: O96009
Gene: NAPSA
Ensembl: ENSG00000131400
Chromosome: 19
Canonical length: 420 aa
Protein class: Enzymes, Plasma proteins, Predicted secreted proteins
Secretome location: Secreted in other tissues

OverviewNCBI Gene

This gene encodes a member of the peptidase A1 family of aspartic proteases. The encoded preproprotein is proteolytically processed to generate an activation peptide and the mature protease. The activation peptides of aspartic proteinases function as inhibitors of the protease 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 encoded protease may play a role in the proteolytic processing of pulmonary surfactant protein B in the lung and may function in protein catabolism in the renal proximal tubules. This gene has been described as a marker for lung adenocarcinoma and renal cell carcinoma. [provided by RefSeq, Feb 2016]

Canonical amino-acid sequenceUniProt

420 residues, UniProt reviewed canonical sequence.

>O96009|NAPSA
     1  MSPPPLLQPL LLLLPLLNVE PSGATLIRIP LHRVQPGRRI LNLLRGWREP AELPKLGAPS
    61  PGDKPIFVPL SNYRDVQYFG EIGLGTPPQN FTVAFDTGSS NLWVPSRRCH FFSVPCWLHH
   121  RFDPKASSSF QANGTKFAIQ YGTGRVDGIL SEDKLTIGGI KGASVIFGEA LWEPSLVFAF
   181  AHFDGILGLG FPILSVEGVR PPMDVLVEQG LLDKPVFSFY LNRDPEEPDG GELVLGGSDP
   241  AHYIPPLTFV PVTVPAYWQI HMERVKVGPG LTLCAKGCAA ILDTGTSLIT GPTEEIRALH
   301  AAIGGIPLLA GEYIILCSEI PKLPAVSFLL GGVWFNLTAH DYVIQTTRNG VRLCLSGFQA
   361  LDVPPPAGPF WILGDVFLGT YVAVFDRGDM KSSARVGLAR ARTRGADLGW GETAQAQFPG

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against NAPSA 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): 0.3
Highest tissue expression: 984 nTPM

Expression across tissuesHPA

Tissue

lung: 984 nTPM
kidney: 92 nTPM
ovary: 2.1 nTPM
testis: 2.1 nTPM
epididymis: 1.8 nTPM
thyroid gland: 1.7 nTPM

Single-cell type

alveolar cells type 2: 5,089 nCPM
alveolar cells type 1: 1,829 nCPM
transitional alveolar cells: 1,534 nCPM
epididymal efferent duct absorptive cells: 381 nCPM
early spermatids: 50 nCPM
proximal tubule cells: 45 nCPM

Immune cell

plasmacytoid DC: 4.9 nTPM
memory B-cell: 2.8 nTPM
naive B-cell: 0.7 nTPM
myeloid DC: 0.5 nTPM
total PBMC: 0.5 nTPM
naive CD4 T-cell: 0.4 nTPM

Brain region

thalamus: 0.6 nTPM
white matter: 0.6 nTPM
medulla oblongata: 0.5 nTPM
basal ganglia: 0.4 nTPM
cerebellum: 0.4 nTPM
cerebral cortex: 0.4 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): 1.63
gnomAD pLI: 0
gnomAD missense Z: 0.16
DepMap mean gene effect: 0.07
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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 NAPSA as an antibody target. Whether an autoantibody or antibody against NAPSA could matter depends on whether native NAPSA is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

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

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