KCNJ16
Potassium Inwardly Rectifying Channel Subfamily J Member 16
Gene Information Card
| Symbol | KCNJ16 |
|---|---|
| Full Name | Potassium Inwardly Rectifying Channel Subfamily J Member 16 |
| Gene Type | protein-coding |
| Chromosomal Location | 17q24.3 |
| NCBI Gene ID | 3773 ncbi.nlm.nih.gov/gene/3773 |
| Ensembl ID | ENSG00000131089 |
| UniProt ID | Q9NPI9 |
| OMIM ID | 605722 |
| HGNC ID | 6262 |
| Aliases | Kir5.1, BIR9, KIR5.1 |
Description
KCNJ16 encodes Kir5.1, an inwardly rectifying potassium channel subunit that forms heteromeric channels with Kir4.1 (KCNJ10). These channels are critical for potassium homeostasis in renal tubules, particularly in the distal nephron, and also function in the brain and pancreas. Mutations in KCNJ16 are associated with renal tubular dysfunction, electrolyte imbalances, and acid-base disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Renal tubular acidosis with hypokalemia | Loss-of-function mutations impair Kir4.1/Kir5.1 channel activity, disrupting potassium recycling in the distal nephron and leading to urinary potassium wasting and acidosis. | ClinVar, PMID: 28341781 |
| Seizures, sensorineural deafness, ataxia, intellectual disability, and electrolyte imbalance (SESAME-like) | Heterozygous or biallelic KCNJ16 variants reduce channel conductance, mimicking Kir4.1 dysfunction and causing neurological and renal phenotypes. | ClinVar, PMID: 28341781 |
| Hypokalemic periodic paralysis | Dysfunction of Kir5.1-containing channels may alter muscle membrane excitability, though direct evidence is limited. | OMIM #605722 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Kidney | 12.5 | Medium |
| Brain | 6.8 | Low |
| Pancreas | 4.2 | Low |
| Liver | 1.1 | Not detected |
| Heart | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 0.0 | No endogenous expression |
| HK-2 (proximal tubule) | 8.3 | Moderate expression |
| SK-N-SH (neuroblastoma) | 3.1 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.512G>A (p.Arg171His) | Missense | <0.01% | Reduced channel activity; associated with renal tubular acidosis |
| c.653C>T (p.Thr218Met) | Missense | <0.01% | Impaired heteromerization with Kir4.1; loss-of-function |
| c.1A>G (p.Met1Val) | Start loss | <0.01% | Complete loss of protein expression; severe phenotype |
Mutation functional classification
Loss of Function (LOF)
Most reported KCNJ16 mutations reduce or abolish potassium conductance, leading to renal and neurological phenotypes.
Gain of Function (GOF)
No gain-of-function mutations have been reported in KCNJ16.
Dominant Negative (DN)
Some missense variants (e.g., p.Arg171His) exert dominant-negative effects on Kir4.1/Kir5.1 heteromeric channels.
View complete mutation data：
Gene Ontology (GO)
Pathways
• REACT:13685 – Potassium Channels
• WP:WP4754 – Inwardly rectifying potassium channels
• KEGG:hsa04742 – Taste transduction
Protein Summary
Kir5.1 (KCNJ16) is a 418-amino acid integral membrane protein with two transmembrane domains and a pore-forming loop. It does not form functional homomeric channels but assembles with Kir4.1 (KCNJ10) to create heteromeric Kir4.1/Kir5.1 channels that exhibit strong inward rectification and pH sensitivity. These channels are essential for potassium recycling in renal distal tubules, contributing to sodium reabsorption and acid-base balance. In the brain, Kir4.1/Kir5.1 channels regulate potassium buffering by glial cells.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KCNJ16 Knockout HEK293 Cell Line | EDJ-KQ5043 | Human | 3773 | Details Get a Quote |
| KCNJ16 Knockout A-549 Cell Line | EDJ-KQ27949 | Human | 3773 | Details Get a Quote |
| KCNJ16 Knockout HeLa Cell Line | EDJ-KQ53721 | Human | 3773 | Details Get a Quote |
| KCNJ16 Knockout HCT 116 Cell Line | EDJ-KQ70683 | Human | 3773 | Details Get a Quote |
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