KCNMB1
Potassium Calcium-Activated Channel Subfamily M Regulatory Beta Subunit 1
Gene Information Card
| Symbol | KCNMB1 |
|---|---|
| Full Name | Potassium Calcium-Activated Channel Subfamily M Regulatory Beta Subunit 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 5q35.1 |
| NCBI Gene ID | 3779 ncbi.nlm.nih.gov/gene/3779 |
| Ensembl ID | ENSG00000113575 |
| UniProt ID | Q16558 |
| OMIM ID | 603951 |
| HGNC ID | 6287 |
| Aliases | BKbeta1, hbeta1, Slo-beta-1 |
Description
KCNMB1 encodes the beta-1 regulatory subunit of the large-conductance calcium-activated potassium (BK) channel. This subunit modulates channel gating by increasing calcium sensitivity and altering voltage dependence. The BK channel is critical for vascular smooth muscle relaxation, neuronal excitability, and auditory hair cell function. Variants in KCNMB1 have been associated with hypertension, asthma, and epilepsy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hypertension | Reduced BK channel calcium sensitivity due to loss-of-function variants impairs vasodilation, leading to increased vascular tone and elevated blood pressure. | ClinVar, PMID: 10903346 |
| Asthma | Altered BK channel activity in airway smooth muscle cells contributes to bronchoconstriction and airway hyperresponsiveness. | ClinVar, PMID: 12615919 |
| Epilepsy | Dysregulation of BK channel function in neurons may predispose to seizure activity. | ClinVar, PMID: 23354101 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Smooth muscle | 12.3 | Medium |
| Brain | 8.7 | Medium |
| Heart | 6.1 | Low |
| Lung | 5.4 | Low |
| Kidney | 4.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Aortic smooth muscle cells | 15.1 | High expression |
| Astrocytes | 9.8 | Medium expression |
| Cardiomyocytes | 7.3 | Medium expression |
| HEK293 | 2.1 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.352G>A (p.Glu118Lys) | Missense | 0.01% | Reduced calcium sensitivity; associated with hypertension |
| c.497C>T (p.Thr166Met) | Missense | 0.005% | Altered channel gating; linked to asthma |
| c.1A>G (p.Met1Val) | Start loss | <0.001% | Loss of protein expression; severe phenotype |
Mutation functional classification
Loss of Function (LOF)
Variants such as p.Glu118Lys reduce BK channel calcium sensitivity, impairing vasodilation and contributing to hypertension.
Gain of Function (GOF)
No confirmed gain-of-function variants reported in KCNMB1.
Dominant Negative (DN)
No dominant-negative variants described for KCNMB1.
View complete mutation data：
Gene Ontology (GO)
| • GO:0005250 – voltage-gated potassium channel activity | • GO:0005515 – protein binding |
| • GO:0015269 – calcium-activated potassium channel activity | • GO:0034705 – potassium channel complex |
| • GO:0071805 – potassium ion transmembrane transport |
Pathways
• hsa04270 – Vascular smooth muscle contraction
• hsa04724 – Glutamatergic synapse
• hsa05030 – Cocaine addiction
Protein Summary
The KCNMB1 protein (BKbeta1) is a 191-amino-acid transmembrane protein with two transmembrane domains and a large extracellular loop. It associates with the pore-forming alpha subunit (KCNMA1) to form the functional BK channel. Beta-1 increases the channel's apparent calcium sensitivity and modulates its voltage dependence, making it essential for proper BK channel function in smooth muscle and neurons.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KCNMB1 Knockout HEK293 Cell Line | EDJ-KQ1844 | Human | 3779 | Details Get a Quote |
| KCNMB1 Knockout HeLa Cell Line | EDJ-KQ53722 | Human | 3779 | Details Get a Quote |
| KCNMB1 Knockout A-549 Cell Line | EDJ-KQ62198 | Human | 3779 | Details Get a Quote |
| KCNMB1 Knockout HCT 116 Cell Line | EDJ-KQ70687 | Human | 3779 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
