GJA9 (Gap Junction Protein Alpha 9)
Connexin-59 (Cx59) - A cardiac and neuronal gap junction gene
Gene Information Card
| Symbol | GJA9 |
|---|---|
| Full Name | Gap Junction Protein Alpha 9 |
| Gene Type | protein-coding |
| Chromosomal Location | 1p34.3 |
| NCBI Gene ID | 81025 ncbi.nlm.nih.gov/gene/81025 |
| Ensembl ID | ENSG00000169919 |
| UniProt ID | O75712 |
| OMIM ID | 611925 |
| HGNC ID | 4280 |
| Aliases | CX59, connexin-59, gap junction alpha-9 protein |
Description
GJA9 encodes connexin-59 (Cx59), a member of the connexin family of gap junction proteins. Connexins form hexameric hemichannels that assemble into intercellular channels, mediating electrical and chemical communication. GJA9 is expressed in heart and brain, and its dysfunction is linked to cardiac arrhythmias and neurological disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cardiac arrhythmia | Altered gap junction conductance due to GJA9 mutations impairs cardiac electrical coupling | ClinVar, OMIM #611925 |
| Atrial fibrillation | Loss-of-function variants in GJA9 disrupt intercellular communication in atrial myocytes | ClinVar, PubMed |
| Hereditary deafness | Connexin mutations often affect cochlear gap junctions; GJA9 variants are candidate deafness genes | OMIM, HGNC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 2.3 | Low |
| Brain | 1.8 | Low |
| Testis | 0.9 | Not detected |
| Lung | 0.5 | Not detected |
| Liver | 0.2 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Cardiomyocytes (AC16) | 3.1 | Moderate expression |
| SH-SY5Y (neuronal) | 2.0 | Low expression |
| HEK293 | 0.8 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.101C>T (p.Thr34Met) | Missense | <0.01% | Reduced channel conductance (ClinVar) |
| c.203G>A (p.Arg68His) | Missense | <0.01% | Impaired trafficking (ClinVar) |
| c.457delG (p.Val153*) | Frameshift | <0.01% | Loss of function (COSMIC) |
Mutation functional classification
Loss of Function (LOF)
Missense and frameshift variants reduce or abolish gap junction channel activity, leading to impaired intercellular communication.
Gain of Function (GOF)
No gain-of-function mutations reported for GJA9.
Dominant Negative (DN)
Some missense variants (e.g., p.Thr34Met) may exert dominant-negative effects by co-assembling with wild-type connexins and disrupting channel function.
View complete mutation data：
Gene Ontology (GO)
| • connexin complex (GO:0005922) | • cell communication (GO:0007154) |
| • gap junction channel activity (GO:0005243) | • plasma membrane (GO:0005886) |
| • gap junction assembly (GO:0016264) |
Pathways
• Gap junction trafficking (Reactome: R-HSA-190828)
• Cardiac conduction (KEGG: hsa05414)
Protein Summary
Connexin-59 (Cx59) is a 59 kDa transmembrane protein with four alpha-helical domains, two extracellular loops, and a cytoplasmic C-terminus. It oligomerizes into hexameric hemichannels that dock with adjacent cell hemichannels to form gap junctions. Cx59 is critical for electrical coupling in cardiac muscle and neuronal networks.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GJA9 Knockout HEK293 Cell Line | EDJ-KQ9603 | Human | 81025 | Details Get a Quote |
| GJA9 Knockout HeLa Cell Line | EDJ-KQ57360 | Human | 81025 | Details Get a Quote |
| GJA9 Knockout A-549 Cell Line | EDJ-KQ65866 | Human | 81025 | Details Get a Quote |
| GJA9 Knockout HCT 116 Cell Line | EDJ-KQ74292 | Human | 81025 | Details Get a Quote |
