Seroatlas · Human Serome Atlas

PPP3CA

Protein phosphatase 3 catalytic subunit alpha

Also known as: CALN, CALNA, CNA1, PP2BA_HUMAN, PPP2B

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

Protein identityUniProt · HPA

UniProt accession
Q08209
Gene
PPP3CA
Ensembl
ENSG00000138814
Chromosome
4
Canonical length
521 aa
Protein class
Disease related genes, Enzymes, Human disease related genes, Plasma proteins, Potential drug targets, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Cytosol,Calyx

OverviewNCBI Gene

Enables several functions, including ATPase binding activity; calmodulin binding activity; and calmodulin-dependent protein phosphatase activity. Involved in several processes, including calcineurin-NFAT signaling cascade; negative regulation of angiotensin-activated signaling pathway; and peptidyl-serine dephosphorylation. Located in cytoplasm; cytoplasmic side of plasma membrane; and dendritic spine. Part of calcineurin complex. Implicated in developmental and epileptic encephalopathy 91. Biomarker of cholangiocarcinoma; focal segmental glomerulosclerosis; and schizophrenia. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

521 residues, UniProt reviewed canonical sequence.

>Q08209|PPP3CA
     1  MSEPKAIDPK LSTTDRVVKA VPFPPSHRLT AKEVFDNDGK PRVDILKAHL MKEGRLEESV
    61  ALRIITEGAS ILRQEKNLLD IDAPVTVCGD IHGQFFDLMK LFEVGGSPAN TRYLFLGDYV
   121  DRGYFSIECV LYLWALKILY PKTLFLLRGN HECRHLTEYF TFKQECKIKY SERVYDACMD
   181  AFDCLPLAAL MNQQFLCVHG GLSPEINTLD DIRKLDRFKE PPAYGPMCDI LWSDPLEDFG
   241  NEKTQEHFTH NTVRGCSYFY SYPAVCEFLQ HNNLLSILRA HEAQDAGYRM YRKSQTTGFP
   301  SLITIFSAPN YLDVYNNKAA VLKYENNVMN IRQFNCSPHP YWLPNFMDVF TWSLPFVGEK
   361  VTEMLVNVLN ICSDDELGSE EDGFDGATAA ARKEVIRNKI RAIGKMARVF SVLREESESV
   421  LTLKGLTPTG MLPSGVLSGG KQTLQSATVE AIEADEAIKG FSPQHKITSF EEAKGLDRIN
   481  ERMPPRRDAM PSDANLNSIN KALTSETNGT DSNGSNSSNI Q

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PPP3CA 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)
0.29
Highest tissue expression
145 nTPM

Expression across tissuesHPA

Tissue

  • basal ganglia: 145 nTPM
  • cerebral cortex: 114 nTPM
  • cerebellum: 95 nTPM
  • hippocampal formation: 84 nTPM
  • prostate: 62 nTPM
  • skeletal muscle: 48 nTPM

Single-cell type

  • prostatic glandular cells: 2,545 nCPM
  • neutrophils: 2,460 nCPM
  • brain inhibitory neurons: 1,381 nCPM
  • brain excitatory neurons: 1,220 nCPM
  • neutrophil progenitors: 1,177 nCPM
  • sertoli cells: 640 nCPM

Immune cell

  • neutrophil: 124 nTPM
  • basophil: 83 nTPM
  • memory B-cell: 74 nTPM
  • eosinophil: 74 nTPM
  • NK-cell: 65 nTPM
  • naive B-cell: 63 nTPM

Brain region

  • basal ganglia: 349 nTPM
  • hippocampal formation: 253 nTPM
  • cerebral cortex: 249 nTPM
  • cerebellum: 182 nTPM
  • white matter: 158 nTPM
  • amygdala: 108 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about PPP3CA.

Disease | AllUniProt

Conditions PPP3CA is implicated in, by any mechanism.

  • Epileptic encephalopathy, infantile or early childhood, 1 (IECEE1) MIM:617711
  • Arthrogryposis, cleft palate, craniosynostosis, and impaired intellectual development (ACCIID) MIM:618265

Disease | GeneticClinVar

50 pathogenic / likely-pathogenic of 615 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.16
gnomAD pLI
1
gnomAD missense Z
3.63
DepMap mean gene effect
0.01
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

InteractionsUniProt · HPA

Protein binding partners of PPP3CA 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 PPP3CA as an antibody target. Whether an autoantibody or antibody against PPP3CA could matter depends on whether native PPP3CA is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PPP3CA is annotated at the cell surface, where native PPP3CA 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 PPP3CA as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/PPP3CA. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...