CHP1: Calcineurin B Homologous Protein 1
A key regulator of ion transport and pH homeostasis, implicated in cancer and neurological disorders.
Gene Information Card
| Symbol | CHP1 |
|---|---|
| Full Name | Calcineurin B Homologous Protein 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 15q15.1 |
| NCBI Gene ID | 11261 ncbi.nlm.nih.gov/gene/11261 |
| Ensembl ID | ENSG00000137807 |
| UniProt ID | Q99653 |
| OMIM ID | 606988 |
| HGNC ID | 1968 |
| Aliases | CHP, p22, SLC9A1BP, calcineurin B homologous protein 1 |
Description
CHP1 encodes a calcium-binding protein that is a critical cofactor for the Na+/H+ exchanger NHE1 (SLC9A1). It regulates intracellular pH, cell volume, and ion homeostasis. CHP1 also interacts with calcineurin and modulates calcium signaling. The gene is ubiquitously expressed and its dysregulation is linked to cancer progression and neurological conditions.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (various types) | CHP1 overexpression enhances NHE1 activity, promoting alkaline intracellular pH and cell proliferation | COSMIC; PMID: 23541953 |
| Hypertension | CHP1 variants may alter NHE1 regulation, affecting vascular tone and blood pressure | ClinVar; PMID: 12871976 |
| Neurological disorders | CHP1 interacts with calcineurin; altered expression linked to neuronal excitability | OMIM #606988; PMID: 15525639 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 28.5 | High |
| Heart | 22.1 | High |
| Kidney | 18.7 | Medium |
| Liver | 12.3 | Medium |
| Lung | 15.4 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 32.1 | High expression; used in functional studies |
| HeLa | 27.8 | Moderate expression |
| K562 | 19.5 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.236C>T (p.Pro79Leu) | Missense | 0.01% (gnomAD) | Alters calcium binding; reduced NHE1 activation |
| c.418G>A (p.Gly140Arg) | Missense | 0.005% (gnomAD) | Impaired interaction with calcineurin |
| c.1A>G (p.Met1?) | Start loss | Rare | Loss of protein expression |
Mutation functional classification
Loss of Function (LOF)
Mutations that disrupt calcium binding or NHE1 interaction reduce pH regulation and cell survival.
Gain of Function (GOF)
Overexpression or activating mutations enhance NHE1 activity, promoting tumorigenesis.
Dominant Negative (DN)
Mutant CHP1 that sequesters calcineurin or NHE1 without proper function can inhibit wild-type activity.
View complete mutation data：
Gene Ontology (GO)
| • calcium ion binding (GO:0005509) | • enzyme binding (GO:0019899) |
| • solute:proton antiporter activity (GO:0015299) | • regulation of pH (GO:0006885) |
| • transmembrane transport (GO:0055085) |
Pathways
• Sodium/proton exchanger (NHE) regulation
• Calcineurin-NFAT signaling
• Ion homeostasis and cell volume control
Protein Summary
CHP1 is a 22 kDa calcium-binding protein that serves as an essential cofactor for the Na+/H+ exchanger NHE1. It binds to the cytoplasmic tail of NHE1 and is required for its activity, thereby regulating intracellular pH and cell volume. CHP1 also interacts with calcineurin, linking calcium signaling to ion transport. The protein is ubiquitously expressed and its dysregulation contributes to cancer and cardiovascular diseases.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CHP1 Knockout HEK293 Cell Line | EDJ-KQ7354 | Human | 11261 | Details Get a Quote |
| CHP1 Knockout A-549 Cell Line | EDJ-KQ32461 | Human | 11261 | Details Get a Quote |
| CHP1 Knockout HCT 116 Cell Line | EDJ-KQ32462 | Human | 11261 | Details Get a Quote |
| CHP1 Knockout HeLa Cell Line | EDJ-KQ32463 | Human | 11261 | Details Get a Quote |
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