KCNMB4
Potassium Calcium-Activated Channel Subfamily M Regulatory Beta Subunit 4
Gene Information Card
| Symbol | KCNMB4 |
|---|---|
| Full Name | Potassium Calcium-Activated Channel Subfamily M Regulatory Beta Subunit 4 |
| Gene Type | Protein coding |
| Chromosomal Location | 12q15 |
| NCBI Gene ID | 27345 ncbi.nlm.nih.gov/gene/27345 |
| Ensembl ID | ENSG00000135446 |
| UniProt ID | Q86W47 |
| OMIM ID | 605223 |
| HGNC ID | 6289 |
| Aliases | BKbeta4, hbeta4, KCNMB4L |
Description
KCNMB4 encodes the beta-4 subunit of the large-conductance voltage- and calcium-activated potassium (BK) channel. This subunit modulates channel gating properties, including calcium sensitivity and voltage dependence, and is predominantly expressed in neuronal tissues. It plays a critical role in regulating neuronal excitability and neurotransmitter release.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Epilepsy | Altered BK channel gating due to KCNMB4 variants may increase neuronal excitability | ClinVar |
| Essential tremor | KCNMB4 variants associated with altered channel function in cerebellar neurons | OMIM |
| Hypertension | Modulation of BK channel in vascular smooth muscle may affect blood pressure regulation | NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | High |
| Cerebellum | 15.3 | High |
| Cerebral cortex | 11.8 | High |
| Testis | 3.2 | Low |
| Heart | 1.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y | 8.7 | Neuronal cell line |
| HEK293 | 0.5 | Low expression |
| U87MG | 6.2 | Glioblastoma cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.421G>A (p.Gly141Ser) | Missense | <0.01% | Altered calcium sensitivity |
| c.538C>T (p.Arg180Trp) | Missense | <0.01% | Reduced channel activity |
| c.1A>G (p.Met1Val) | Start loss | <0.01% | Loss of protein expression |
Mutation functional classification
Loss of Function (LOF)
p.Arg180Trp reduces BK channel activity
Gain of Function (GOF)
Not reported
Dominant Negative (DN)
Not reported
View complete mutation data：
Gene Ontology (GO)
| • voltage-gated potassium channel activity | • calcium-activated potassium channel activity |
| • plasma membrane | • regulation of membrane potential |
| • neuronal action potential |
Pathways
• Potassium channels
• Calcium signaling pathway
• Neuronal system
Protein Summary
The KCNMB4 protein (beta-4 subunit) is a transmembrane auxiliary subunit of the BK channel. It modulates channel kinetics by increasing calcium sensitivity and slowing activation/deactivation. It is essential for proper neuronal firing and neurotransmitter release.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KCNMB4 Knockout HEK293 Cell Line | EDJ-KQ1846 | Human | 27345 | Details Get a Quote |
| KCNMB4 Knockout HCT 116 Cell Line | EDJ-KQ21703 | Human | 27345 | Details Get a Quote |
| KCNMB4 Knockout HeLa Cell Line | EDJ-KQ21704 | Human | 27345 | Details Get a Quote |
| KCNMB4 Knockout A-549 Cell Line | EDJ-KQ64547 | Human | 27345 | Details Get a Quote |
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