Seroatlas · Human Serome Atlas

PPP3CB

Serine/threonine-protein phosphatase 2B catalytic subunit beta isoform

Also known as: CALNA2, CALNB, CNA2, PP2BB_HUMAN, PP2Bbeta

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

Protein identityUniProt · HPA

UniProt accession: P16298
Gene: PPP3CB
Ensembl: ENSG00000107758
Chromosome: 10
Canonical length: 524 aa
Protein class: Enzymes, Predicted intracellular proteins
Subcellular location: Nucleoplasm,Cytosol,Calyx

OverviewNCBI Gene

Enables several functions, including calmodulin binding activity; calmodulin-dependent protein phosphatase activity; and protein phosphatase 2B binding activity. Involved in several processes, including calcineurin-NFAT signaling cascade; positive regulation of lysosome organization; and positive regulation of protein localization to nucleus. Located in cytoplasm. Part of calcineurin complex. Implicated in aortic valve stenosis. Biomarker of focal segmental glomerulosclerosis and schizophrenia. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

524 residues, UniProt reviewed canonical sequence.

>P16298|PPP3CB
     1  MAAPEPARAA PPPPPPPPPP PGADRVVKAV PFPPTHRLTS EEVFDLDGIP RVDVLKNHLV
    61  KEGRVDEEIA LRIINEGAAI LRREKTMIEV EAPITVCGDI HGQFFDLMKL FEVGGSPANT
   121  RYLFLGDYVD RGYFSIECVL YLWVLKILYP STLFLLRGNH ECRHLTEYFT FKQECKIKYS
   181  ERVYEACMEA FDSLPLAALL NQQFLCVHGG LSPEIHTLDD IRRLDRFKEP PAFGPMCDLL
   241  WSDPSEDFGN EKSQEHFSHN TVRGCSYFYN YPAVCEFLQN NNLLSIIRAH EAQDAGYRMY
   301  RKSQTTGFPS LITIFSAPNY LDVYNNKAAV LKYENNVMNI RQFNCSPHPY WLPNFMDVFT
   361  WSLPFVGEKV TEMLVNVLSI CSDDELMTEG EDQFDGSAAA RKEIIRNKIR AIGKMARVFS
   421  VLREESESVL TLKGLTPTGM LPSGVLAGGR QTLQSATVEA IEAEKAIRGF SPPHRICSFE
   481  EAKGLDRINE RMPPRKDAVQ QDGFNSLNTA HATENHGTGN HTAQ

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PPP3CB 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): 0.31
Highest tissue expression: 356 nTPM

Expression across tissuesHPA

Tissue

skeletal muscle: 356 nTPM
tongue: 168 nTPM
cerebral cortex: 87 nTPM
cerebellum: 86 nTPM
retina: 53 nTPM
hippocampal formation: 50 nTPM

Single-cell type

myonuclei: 417 nCPM
retinal ganglion cells: 205 nCPM
fibro-adipogenic progenitors: 186 nCPM
choroid plexus epithelial cells: 183 nCPM
brain excitatory neurons: 178 nCPM
lactotrophs: 175 nCPM

Immune cell

T-reg: 7.8 nTPM
naive CD8 T-cell: 5.2 nTPM
MAIT T-cell: 4.8 nTPM
memory CD4 T-cell: 4.4 nTPM
memory CD8 T-cell: 4.4 nTPM
gdT-cell: 4.1 nTPM

Brain region

cerebral cortex: 136 nTPM
cerebellum: 122 nTPM
basal ganglia: 122 nTPM
hippocampal formation: 118 nTPM
white matter: 109 nTPM
hypothalamus: 82 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): 0.1
gnomAD pLI: 1
gnomAD missense Z: 3.79
DepMap mean gene effect: -0.08
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 PPP3CB 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 PPP3CB as an antibody target. Whether an autoantibody or antibody against PPP3CB could matter depends on whether native PPP3CB is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PPP3CB 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 PPP3CB as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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