Seroatlas · Human Serome Atlas

CAPN8

Calpain-8

Also known as: CAN8_HUMAN, nCL-2

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

Protein identityUniProt · HPA

UniProt accession: A6NHC0
Gene: CAPN8
Ensembl: ENSG00000203697
Chromosome: 1
Canonical length: 703 aa
Protein class: Enzymes, Predicted intracellular proteins
Subcellular location: Nucleoplasm,Nuclear membrane,Vesicles
Quaternary structure: Homooligomer

OverviewNCBI Gene

Predicted to enable calcium-dependent cysteine-type endopeptidase activity and identical protein binding activity. Predicted to be involved in proteolysis. Predicted to act upstream of or within calcium-dependent self proteolysis. Predicted to be located in Golgi apparatus. Predicted to be active in cytoplasm. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

703 residues, UniProt reviewed canonical sequence.

>A6NHC0|CAPN8
     1  MAAQAAGVSR QRAATQGLGS NQNALKYLGQ DFKTLRQQCL DSGVLFKDPE FPACPSALGY
    61  KDLGPGSPQT QGIIWKRPTE LCPSPQFIVG GATRTDICQG GLGDCWLLAA IASLTLNEEL
   121  LYRVVPRDQD FQENYAGIFH FQFWQYGEWV EVVIDDRLPT KNGQLLFLHS EQGNEFWSAL
   181  LEKAYAKLNG CYEALAGGST VEGFEDFTGG ISEFYDLKKP PANLYQIIRK ALCAGSLLGC
   241  SIDVSSAAEA EAITSQKLVK SHAYSVTGVE EVNFQGHPEK LIRLRNPWGE VEWSGAWSDD
   301  APEWNHIDPR RKEELDKKVE DGEFWMSLSD FVRQFSRLEI CNLSPDSLSS EEVHKWNLVL
   361  FNGHWTRGST AGGCQNYPAT YWTNPQFKIR LDEVDEDQEE SIGEPCCTVL LGLMQKNRRW
   421  RKRIGQGMLS IGYAVYQVPK ELESHTDAHL GRDFFLAYQP SARTSTYVNL REVSGRARLP
   481  PGEYLVVPST FEPFKDGEFC LRVFSEKKAQ ALEIGDVVAG NPYEPHPSEV DQEDDQFRRL
   541  FEKLAGKDSE ITANALKILL NEAFSKRTDI KFDGFNINTC REMISLLDSN GTGTLGAVEF
   601  KTLWLKIQKY LEIYWETDYN HSGTIDAHEM RTALRKAGFT LNSQVQQTIA LRYACSKLGI
   661  NFDSFVACMI RLETLFKLFS LLDEDKDGMV QLSLAEWLCC VLV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CAPN8 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: Intracellular
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.25
Highest tissue expression: 275 nTPM

Expression across tissuesHPA

Tissue

stomach: 275 nTPM
rectum: 31 nTPM
colon: 22 nTPM
lung: 20 nTPM
urinary bladder: 16 nTPM
breast: 14 nTPM

Single-cell type

foveolar cells: 1,721 nCPM
alveolar cells type 2: 294 nCPM
papillary tip epithelial cells: 254 nCPM
transitional alveolar cells: 229 nCPM
prostatic club cells: 227 nCPM
renal collecting duct principal cells: 200 nCPM

Immune cell

total PBMC: 0.2 nTPM
gdT-cell: 0.1 nTPM
naive CD8 T-cell: 0.1 nTPM
neutrophil: 0.1 nTPM
basophil: 0 nTPM
classical monocyte: 0 nTPM

Brain region

amygdala: 11 nTPM
choroid plexus: 6 nTPM
hypothalamus: 5.9 nTPM
cerebral cortex: 5.7 nTPM
medulla oblongata: 5.1 nTPM
hippocampal formation: 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): 1.02
gnomAD pLI: 0
gnomAD missense Z: 0.84

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

proteolysis

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of CAPN8 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 CAPN8 as an antibody target. Whether an autoantibody or antibody against CAPN8 could matter depends on whether native CAPN8 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CAPN8 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label CAPN8 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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