KCNU1
Potassium Calcium-Activated Channel Subfamily U Member 1
Gene Information Card
| Symbol | KCNU1 |
|---|---|
| Full Name | Potassium Calcium-Activated Channel Subfamily U Member 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 8p11.23 |
| NCBI Gene ID | 157855 ncbi.nlm.nih.gov/gene/157855 |
| Ensembl ID | ENSG00000186185 |
| UniProt ID | A8MYU2 |
| OMIM ID | 615215 |
| HGNC ID | 26463 |
| Aliases | SLO3, KCNMC1, MGC138499 |
Description
KCNU1 (Potassium Calcium-Activated Channel Subfamily U Member 1) encodes a pore-forming subunit of the sperm-specific potassium channel KSper (also known as SLO3). This channel is activated by intracellular alkalinization and plays a critical role in sperm capacitation, hyperpolarization of the sperm membrane potential, and male fertility. Mutations in KCNU1 are associated with asthenozoospermia and male infertility.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Male infertility due to asthenozoospermia | Loss-of-function mutations in KCNU1 impair KSper channel activity, preventing sperm hyperpolarization and motility | ClinVar, OMIM |
| Spermatogenic failure 19 | Homozygous or compound heterozygous mutations in KCNU1 disrupt sperm function | OMIM #618433 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 0.0 | Not detected (specific to sperm cells, not bulk tissue) |
| Fallopian tube | 0.0 | Not detected |
| Prostate | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Spermatozoa | N/A | High expression in mature sperm; KSper channel functional |
| HEK293 | N/A | Not expressed endogenously; used for heterologous expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1270C>T (p.Arg424*) | Nonsense | Rare | Loss of function; truncated protein |
| c.1682G>A (p.Arg561His) | Missense | Rare | Impaired channel activation |
| c.2113C>T (p.Arg705Cys) | Missense | Rare | Reduced current amplitude |
Mutation functional classification
Loss of Function (LOF)
Most reported KCNU1 mutations result in loss of KSper channel function, leading to failure of sperm membrane hyperpolarization and impaired motility.
Gain of Function (GOF)
No gain-of-function mutations have been reported for KCNU1.
Dominant Negative (DN)
No dominant-negative effects have been described; mutations are typically recessive.
View complete mutation data：
Gene Ontology (GO)
| • potassium channel activity (GO:0005267) | • potassium ion transport (GO:0006813) |
| • integral component of membrane (GO:0016021) | • potassium ion transmembrane transport (GO:0071805) |
| • single fertilization (GO:0007338) | • sperm capacitation (GO:0048240) |
Pathways
• Sperm capacitation (Reactome: R-HSA-2534343)
• Potassium channels (KEGG: hsa04740)
Protein Summary
The KCNU1 protein (SLO3) is a 1,113-amino acid voltage- and calcium-activated potassium channel subunit expressed exclusively in sperm. It forms a homotetrameric channel that is activated by intracellular alkalinization and membrane depolarization. KSper is essential for the hyperpolarization of the sperm membrane potential during capacitation, a prerequisite for acrosome reaction and fertilization.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KCNU1 Knockout HEK293 Cell Line | EDJ-KQ1843 | Human | 157855 | Details Get a Quote |
| KCNU1 Knockout HeLa Cell Line | EDJ-KQ58771 | Human | 157855 | Details Get a Quote |
| KCNU1 Knockout A-549 Cell Line | EDJ-KQ67252 | Human | 157855 | Details Get a Quote |
| KCNU1 Knockout HCT 116 Cell Line | EDJ-KQ75651 | Human | 157855 | Details Get a Quote |
