Seroatlas · Human Serome Atlas

CHP2

Calcineurin B homologous protein 2

Also known as: CHP2_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
O43745
Gene
CHP2
Ensembl
ENSG00000166869
Chromosome
16
Canonical length
196 aa
Protein class
Cancer-related genes, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Nucleoli,Cytosol

OverviewNCBI Gene

This gene product is a small calcium-binding protein that regulates cell pH by controlling plasma membrane-type Na+/H+ exchange activity. This protein shares sequence similarity with calcineurin B and can bind to and stimulate the protein phosphatase activity of calcineurin A (CnA) and functions in the calcineurin/NFAT (nuclear factor of activated T cells) signaling pathway. Another member of the CHP subfamily, Calcineurin B homologous protein 1, is located on Chromosome 15 and is an inhibitor of calcineurin activity and has a genetic phenotype associated with Parkinson's Disease (OMIM:606988). This gene was initially identified as a tumor-associated antigen and was previously referred to as Hepatocellular carcinoma-associated antigen 520. [provided by RefSeq, Jul 2013]

Canonical amino-acid sequenceUniProt

196 residues, UniProt reviewed canonical sequence.

>O43745|CHP2
     1  MGSRSSHAAV IPDGDSIRRE TGFSQASLLR LHHRFRALDR NKKGYLSRMD LQQIGALAVN
    61  PLGDRIIESF FPDGSQRVDF PGFVRVLAHF RPVEDEDTET QDPKKPEPLN SRRNKLHYAF
   121  QLYDLDRDGK ISRHEMLQVL RLMVGVQVTE EQLENIADRT VQEADEDGDG AVSFVEFTKS
   181  LEKMDVEQKM SIRILK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CHP2 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)
0.33
Highest tissue expression
287 nTPM

Expression across tissuesHPA

Tissue

  • duodenum: 287 nTPM
  • small intestine: 236 nTPM
  • skin: 141 nTPM
  • rectum: 139 nTPM
  • colon: 138 nTPM
  • cervix: 13 nTPM

Single-cell type

  • enterocytes: 582 nCPM
  • colonocytes: 321 nCPM
  • enteric transient amplifying cells: 235 nCPM
  • enteric stem cells: 136 nCPM
  • paneth cells: 93 nCPM
  • respiratory secretory cells: 72 nCPM

Immune cell

  • neutrophil: 0.2 nTPM
  • memory CD8 T-cell: 0.1 nTPM
  • naive B-cell: 0.1 nTPM
  • naive CD4 T-cell: 0.1 nTPM
  • plasmacytoid DC: 0.1 nTPM
  • basophil: 0 nTPM

Brain region

  • cerebellum: 18 nTPM
  • white matter: 15 nTPM
  • hypothalamus: 14 nTPM
  • cerebral cortex: 13 nTPM
  • pons: 13 nTPM
  • basal ganglia: 13 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)
1.47
gnomAD pLI
0
gnomAD missense Z
-0.68
DepMap mean gene effect
-0.05
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 CHP2 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 CHP2 as an antibody target. Whether an autoantibody or antibody against CHP2 could matter depends on whether native CHP2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CHP2 is annotated at the cell surface, where native CHP2 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 CHP2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CHP2. 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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