Seroatlas · Human Serome Atlas

CNTN3

Contactin-3

Also known as: BIG-1, CNTN3_HUMAN, PANG

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

Protein identityUniProt · HPA

UniProt accession: Q9P232
Gene: CNTN3
Ensembl: ENSG00000113805
Chromosome: 3
Canonical length: 1028 aa
Protein class: Plasma proteins, Predicted intracellular proteins
Secretome location: Intracellular and membrane

OverviewNCBI Gene

Predicted to be involved in cell adhesion. Predicted to be located in extracellular region and plasma membrane. Predicted to be active in neuron projection. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

1028 residues, UniProt reviewed canonical sequence.

>Q9P232|CNTN3
     1  MMFPWKQLIL LSFIGCLGGE LLLQGPVFIK EPSNSIFPVG SEDKKITLHC EARGNPSPHY
    61  RWQLNGSDID MSMEHRYKLN GGNLVVINPN RNWDTGTYQC FATNSLGTIV SREAKLQFAY
   121  LENFKTKMRS TVSVREGQGV VLLCGPPPHS GELSYAWIFN EYPSFVEEDS RRFVSQETGH
   181  LYISKVEPSD VGNYTCVVTS MVTNARVLGS PTPLVLRSDG VMGEYEPKIE VQFPETLPAA
   241  KGSTVKLECF ALGNPIPQIN WRRSDGLPFS SKIKLRKFSG VLEIPNFQQE DAGSYECIAE
   301  NSRGKNVARG RLTYYAKPHW VQLIKDVEIA VEDSLYWECR ASGKPKPSYR WLKNGAALVL
   361  EERTQIENGA LTISNLSVTD SGMFQCIAEN KHGLVYSSAE LKVVASAPDF SKNPMKKLVQ
   421  VQVGSLVSLD CKPRASPRAL SSWKKGDVSV QEHERISLLN DGGLKIANVT KADAGTYTCM
   481  AENQFGKANG TTHLVVTEPT RITLAPSNMD VSVGESVILP CQVQHDPLLD IIFTWYFNGA
   541  LADFKKDGSH FEKVGGSSSG DLMIRNIQLK HSGKYVCMVQ TGVDSVSSAA DLIVRGSPGP
   601  PENVKVDEIT DTTAQLSWKE GKDNHSPVIS YSIQARTPFS VGWQTVTTVP EVIDGKTHTA
   661  TVVELNPWVE YEFRVVASNK IGGGEPSLPS EKVRTEEAVP EVPPSEVNGG GGSRSELVIT
   721  WDPVPEELQN GEGFGYVVAF RPLGVTTWIQ TVVTSPDTPR YVFRNESIVP YSPYEVKVGV
   781  YNNKGEGPFS PVTTVFSAEE EPTVAPSQVS ANSLSSSEIE VSWNTIPWKL SNGHLLGYEV
   841  RYWNGGGKEE SSSKMKVAGN ETSARLRGLK SNLAYYTAVR AYNSAGAGPF SATVNVTTKK
   901  TPPSQPPGNV VWNATDTKVL LNWEQVKAME NESEVTGYKV FYRTSSQNNV QVLNTNKTSA
   961  ELVLPIKEDY IIEVKATTDG GDGTSSEQIR IPRITSMDAR GSTSAISNVH PMSSYMPIVL
  1021  FLIVYVLW

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CNTN3 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: 0
Mean surface accessibility (rSASA): 0.31
Highest tissue expression: 7 nTPM

Expression across tissuesHPA

Tissue

cerebral cortex: 7 nTPM
fallopian tube: 6.7 nTPM
blood vessel: 5.2 nTPM
prostate: 5.2 nTPM
amygdala: 3.8 nTPM
seminal vesicle: 3.7 nTPM

Single-cell type

pituitary stem cells: 892 nCPM
retinal pigment epithelial cells: 550 nCPM
ependymal cells: 482 nCPM
adrenal medulla cells: 394 nCPM
corticotrophs: 326 nCPM
gonadotrophs: 318 nCPM

Immune cell

basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM
intermediate monocyte: 0 nTPM
MAIT T-cell: 0 nTPM

Brain region

cerebral cortex: 1,682 nTPM
pons: 60 nTPM
medulla oblongata: 40 nTPM
white matter: 36 nTPM
hippocampal formation: 36 nTPM
basal ganglia: 27 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): 0.51
gnomAD pLI: 0
gnomAD missense Z: 1.32
DepMap mean gene effect: -0.02
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

cell adhesion

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of CNTN3 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

PTPRG

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CNTN3 as an antibody target. Whether an autoantibody or antibody against CNTN3 could matter depends on whether native CNTN3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CNTN3 is annotated at the cell surface, where native CNTN3 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 CNTN3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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