KCNMB3
Potassium Calcium-Activated Channel Subfamily M Regulatory Beta Subunit 3
Gene Information Card
| Symbol | KCNMB3 |
|---|---|
| Full Name | Potassium Calcium-Activated Channel Subfamily M Regulatory Beta Subunit 3 |
| Gene Type | Protein coding |
| Chromosomal Location | 3q26.32 |
| NCBI Gene ID | 27094 ncbi.nlm.nih.gov/gene/27094 |
| Ensembl ID | ENSG00000171049 |
| UniProt ID | Q9NPA1 |
| OMIM ID | 605222 |
| HGNC ID | 6286 |
| Aliases | KCNMB3, BKbeta3, KCa1.1 beta3, hbeta3 |
Description
KCNMB3 (Potassium Calcium-Activated Channel Subfamily M Regulatory Beta Subunit 3) is a protein-coding gene located on chromosome 3q26.32. It encodes a regulatory beta subunit of the large-conductance calcium-activated potassium (BK) channel, also known as KCa1.1. This subunit modulates channel gating properties, including calcium sensitivity and voltage dependence. Alternative splicing generates multiple isoforms with distinct functional effects. KCNMB3 is expressed in various tissues, including brain, smooth muscle, and testis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Epilepsy | Altered BK channel function due to KCNMB3 variants may affect neuronal excitability and seizure susceptibility. | Limited evidence from case-control studies and functional assays. |
| Hypertension | Modulation of BK channel activity in vascular smooth muscle may influence blood pressure regulation. | Association studies with conflicting results; further validation needed. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Testis | 8.3 | Low |
| Smooth muscle | 6.7 | Low |
| Heart | 4.2 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 5.1 | Low expression |
| SH-SY5Y | 8.9 | Moderate expression |
| A549 | 3.4 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.434C>T (p.Pro145Leu) | Missense | Rare | Reduced calcium sensitivity of BK channel |
| c.622G>A (p.Gly208Ser) | Missense | Rare | Altered voltage dependence |
Mutation functional classification
Loss of Function (LOF)
p.Pro145Leu reduces BK channel calcium sensitivity, leading to decreased channel activity.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported.
Dominant Negative (DN)
Not established for KCNMB3.
View complete mutation data：
Gene Ontology (GO)
| • GO:0005250 – voltage-gated potassium channel activity | • GO:0005267 – potassium channel activity |
| • GO:0005515 – protein binding | • GO:0015459 – potassium channel regulator activity |
| • GO:0034705 – potassium channel complex | • GO:0071805 – potassium ion transmembrane transport |
Pathways
• REAC:R-HSA-1296072 – Voltage gated Potassium channels
• REAC:R-HSA-5576893 – Phase 0 – rapid depolarisation
• KEGG:hsa04742 – Taste transduction
Protein Summary
The KCNMB3 protein (UniProt Q9NPA1) is a 279-amino acid regulatory beta subunit of the large-conductance calcium-activated potassium (BK) channel. It contains two transmembrane domains and a large extracellular loop. KCNMB3 modulates BK channel gating by altering calcium and voltage sensitivity. Multiple splice variants exist, with tissue-specific expression patterns. The protein is involved in neuronal excitability, smooth muscle contraction, and hormone secretion.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KCNMB3 Knockout HEK293 Cell Line | EDJ-KQ1845 | Human | 27094 | Details Get a Quote |
| KCNMB3 Knockout A-549 Cell Line | EDJ-KQ21701 | Human | 27094 | Details Get a Quote |
| KCNMB3 Knockout HeLa Cell Line | EDJ-KQ21702 | Human | 27094 | Details Get a Quote |
| KCNMB3 Knockout HCT 116 Cell Line | EDJ-KQ72943 | Human | 27094 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
