Seroatlas · Human Serome Atlas

NPTN

Neuroplastin

Also known as: GP55, GP65, np55, np65, NPTN_HUMAN, SDFR1, SDR1

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

Protein identityUniProt · HPA

UniProt accession
Q9Y639
Gene
NPTN
Ensembl
ENSG00000156642
Chromosome
15
Canonical length
398 aa
Protein class
Predicted intracellular proteins, Predicted membrane proteins, Transporters
Subcellular location
Plasma membrane

OverviewNCBI Gene

This gene encodes a type I transmembrane protein belonging to the Ig superfamily. The protein is believed to be involved in cell-cell interactions or cell-substrate interactions. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2009]

Canonical amino-acid sequenceUniProt

398 residues, UniProt reviewed canonical sequence.

>Q9Y639|NPTN
     1  MSGSSLPSAL ALSLLLVSGS LLPGPGAAQN AGFVKSPMSE TKLTGDAFEL YCDVVGSPTP
    61  EIQWWYAEVN RAESFRQLWD GARKRRVTVN TAYGSNGVSV LRITRLTLED SGTYECRASN
   121  DPKRNDLRQN PSITWIRAQA TISVLQKPRI VTSEEVIIRD SPVLPVTLQC NLTSSSHTLT
   181  YSYWTKNGVE LSATRKNASN MEYRINKPRA EDSGEYHCVY HFVSAPKANA TIEVKAAPDI
   241  TGHKRSENKN EGQDATMYCK SVGYPHPDWI WRKKENGMPM DIVNTSGRFF IINKENYTEL
   301  NIVNLQITED PGEYECNATN AIGSASVVTV LRVRSHLAPL WPFLGILAEI IILVVIIVVY
   361  EKRKRPDEVP DDDEPAGPMK TNSTNNHKDK NLRQRNTN

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against NPTN 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
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.38
Highest tissue expression
279 nTPM

Expression across tissuesHPA

Tissue

  • smooth muscle: 279 nTPM
  • cerebral cortex: 211 nTPM
  • seminal vesicle: 192 nTPM
  • blood vessel: 192 nTPM
  • heart muscle: 184 nTPM
  • choroid plexus: 169 nTPM

Single-cell type

  • neutrophil progenitors: 443 nCPM
  • neutrophils: 438 nCPM
  • retinal bipolar cells: 342 nCPM
  • brain inhibitory neurons: 307 nCPM
  • platelets: 278 nCPM
  • brain excitatory neurons: 248 nCPM

Immune cell

  • neutrophil: 28 nTPM
  • intermediate monocyte: 19 nTPM
  • non-classical monocyte: 15 nTPM
  • eosinophil: 14 nTPM
  • classical monocyte: 14 nTPM
  • total PBMC: 14 nTPM

Brain region

  • cerebral cortex: 434 nTPM
  • basal ganglia: 300 nTPM
  • hippocampal formation: 297 nTPM
  • white matter: 274 nTPM
  • amygdala: 262 nTPM
  • choroid plexus: 254 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about NPTN.

Disease | GeneticClinVar

7 pathogenic / likely-pathogenic of 48 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • NPTN-related neurodevelopmental disorder
  • NPTN-associated neurodevelopmental disorder

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)
0.25
gnomAD pLI
0.99
gnomAD missense Z
2.68
DepMap mean gene effect
0.02
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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 NPTN 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 NPTN as an antibody target. Whether an autoantibody or antibody against NPTN could matter depends on whether native NPTN is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

NPTN is annotated at the cell surface, where native NPTN is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label NPTN as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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