Seroatlas · Human Serome Atlas

CASP9

Caspase-9

Also known as: APAF-3, CASP9_HUMAN, ICE-LAP6, MCH6, PPP1R56

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

Protein identityUniProt · HPA

UniProt accession
P55211
Gene
CASP9
Ensembl
ENSG00000132906
Chromosome
1
Canonical length
416 aa
Protein class
Cancer-related genes, Enzymes, Predicted intracellular proteins
Subcellular location
Mitochondria

OverviewNCBI Gene

This gene encodes a member of the cysteine-aspartic acid protease (caspase) family. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes which undergo proteolytic processing at conserved aspartic residues to produce two subunits, large and small, that dimerize to form the active enzyme. This protein can undergo autoproteolytic processing and activation by the apoptosome, a protein complex of cytochrome c and the apoptotic peptidase activating factor 1; this step is thought to be one of the earliest in the caspase activation cascade. This protein is thought to play a central role in apoptosis and to be a tumor suppressor. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2013]

Canonical amino-acid sequenceUniProt

416 residues, UniProt reviewed canonical sequence.

>P55211|CASP9
     1  MDEADRRLLR RCRLRLVEEL QVDQLWDALL SRELFRPHMI EDIQRAGSGS RRDQARQLII
    61  DLETRGSQAL PLFISCLEDT GQDMLASFLR TNRQAAKLSK PTLENLTPVV LRPEIRKPEV
   121  LRPETPRPVD IGSGGFGDVG ALESLRGNAD LAYILSMEPC GHCLIINNVN FCRESGLRTR
   181  TGSNIDCEKL RRRFSSLHFM VEVKGDLTAK KMVLALLELA QQDHGALDCC VVVILSHGCQ
   241  ASHLQFPGAV YGTDGCPVSV EKIVNIFNGT SCPSLGGKPK LFFIQACGGE QKDHGFEVAS
   301  TSPEDESPGS NPEPDATPFQ EGLRTFDQLD AISSLPTPSD IFVSYSTFPG FVSWRDPKSG
   361  SWYVETLDDI FEQWAHSEDL QSLLLRVANA VSVKGIYKQM PGCFNFLRKK LFFKTS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CASP9 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)
0.32
Highest tissue expression
52 nTPM

Expression across tissuesHPA

Tissue

  • ovary: 52 nTPM
  • adrenal gland: 49 nTPM
  • pancreas: 36 nTPM
  • pituitary gland: 33 nTPM
  • thyroid gland: 27 nTPM
  • testis: 27 nTPM

Single-cell type

  • somatotrophs: 91 nCPM
  • neutrophils: 88 nCPM
  • monocytes: 76 nCPM
  • cdc: 70 nCPM
  • lactotrophs: 68 nCPM
  • esophageal apical cells: 64 nCPM

Immune cell

  • eosinophil: 55 nTPM
  • basophil: 55 nTPM
  • neutrophil: 37 nTPM
  • naive B-cell: 30 nTPM
  • NK-cell: 29 nTPM
  • myeloid DC: 25 nTPM

Brain region

  • white matter: 24 nTPM
  • cerebellum: 21 nTPM
  • medulla oblongata: 21 nTPM
  • thalamus: 19 nTPM
  • midbrain: 19 nTPM
  • cerebral cortex: 19 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)
0.97
gnomAD pLI
0
gnomAD missense Z
0.03
DepMap mean gene effect
-0.02
DepMap dependency class
selective

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

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of CASP9 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 CASP9 as an antibody target. Whether an autoantibody or antibody against CASP9 could matter depends on whether native CASP9 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CASP9 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 CASP9 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CASP9. 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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