Seroatlas · Human Serome Atlas

CHP1

Calcineurin B homologous protein 1

Also known as: CHP, CHP1_HUMAN, p22, p24, Sid470p, SLC9A1BP

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

Protein identityUniProt · HPA

UniProt accession
Q99653
Gene
CHP1
Ensembl
ENSG00000187446
Chromosome
15
Canonical length
195 aa
Protein class
Disease related genes, Human disease related genes, Plasma proteins, Potential drug targets, Predicted intracellular proteins, Transporters
Subcellular location
Vesicles

OverviewNCBI Gene

This gene encodes a phosphoprotein that binds to the Na+/H+ exchanger NHE1. This protein serves as an essential cofactor which supports the physiological activity of NHE family members and may play a role in the mitogenic regulation of NHE1. The protein shares similarity with calcineurin B and calmodulin and it is also known to be an endogenous inhibitor of calcineurin activity. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

195 residues, UniProt reviewed canonical sequence.

>Q99653|CHP1
     1  MGSRASTLLR DEELEEIKKE TGFSHSQITR LYSRFTSLDK GENGTLSRED FQRIPELAIN
    61  PLGDRIINAF FPEGEDQVNF RGFMRTLAHF RPIEDNEKSK DVNGPEPLNS RSNKLHFAFR
   121  LYDLDKDEKI SRDELLQVLR MMVGVNISDE QLGSIADRTI QEADQDGDSA ISFTEFVKVL
   181  EKVDVEQKMS IRFLH

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CHP1 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)
0.32
Highest tissue expression
173 nTPM

Expression across tissuesHPA

Tissue

  • liver: 173 nTPM
  • colon: 107 nTPM
  • stomach: 106 nTPM
  • tongue: 81 nTPM
  • duodenum: 80 nTPM
  • skeletal muscle: 79 nTPM

Single-cell type

  • esophageal apical cells: 923 nCPM
  • parietal cells: 824 nCPM
  • enterocytes: 494 nCPM
  • colonocytes: 443 nCPM
  • hepatocytes: 418 nCPM
  • gastric chief cells: 320 nCPM

Immune cell

  • eosinophil: 275 nTPM
  • basophil: 256 nTPM
  • classical monocyte: 227 nTPM
  • non-classical monocyte: 208 nTPM
  • intermediate monocyte: 204 nTPM
  • neutrophil: 173 nTPM

Brain region

  • pons: 89 nTPM
  • hypothalamus: 82 nTPM
  • medulla oblongata: 82 nTPM
  • midbrain: 78 nTPM
  • hippocampal formation: 75 nTPM
  • white matter: 72 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about CHP1.

Disease | AllUniProt

Conditions CHP1 is implicated in, by any mechanism.

  • Spastic ataxia 9, autosomal recessive (SPAX9) MIM:618438

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 11 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Spastic ataxia 9, autosomal recessive

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)
0.54
gnomAD pLI
0.63
gnomAD missense Z
2.26
DepMap mean gene effect
-0.18
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 CHP1 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 CHP1 as an antibody target. Whether an autoantibody or antibody against CHP1 could matter depends on whether native CHP1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CHP1 is annotated at the cell surface, where native CHP1 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 CHP1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CHP1. 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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