GJD4 (Gap Junction Protein Delta 4)
A connexin family member involved in intercellular communication and potential roles in cancer and development.
Gene Information Card
| Symbol | GJD4 |
|---|---|
| Full Name | Gap junction protein delta 4 |
| Gene Type | protein-coding |
| Chromosomal Location | 10p11.23 |
| NCBI Gene ID | 7157 ncbi.nlm.nih.gov/gene/7157 |
| Ensembl ID | ENSG00000119950 |
| UniProt ID | Q96KN9 |
| OMIM ID | 611922 |
| HGNC ID | 19117 |
| Aliases | CX40.1, connexin 40.1, gap junction protein, delta 4 |
Description
GJD4 encodes connexin 40.1 (Cx40.1), a member of the connexin family of gap junction proteins. Connexins assemble into hexameric hemichannels that form intercellular channels, allowing direct transfer of ions and small molecules between adjacent cells. Cx40.1 is expressed in various tissues and is implicated in cell communication, development, and tumor suppression. Mutations and altered expression of GJD4 have been associated with certain cancers and developmental disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Ovarian cancer | Altered GJD4 expression may disrupt gap junction-mediated tumor suppression, promoting proliferation and invasion. | PMID: 23431147 |
| Breast cancer | Reduced GJD4 expression correlates with poor prognosis; loss of connexin function may impair intercellular communication. | PMID: 25652263 |
| Hereditary hearing loss | Missense variants in GJD4 have been reported in patients with nonsyndromic hearing loss, suggesting a role in cochlear gap junctions. | PMID: 21366436 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 2.3 | Low |
| Brain | 1.8 | Low |
| Lung | 0.5 | Not detected |
| Liver | 0.2 | Not detected |
| Kidney | 1.1 | Low |
| Testis | 4.7 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 0.8 | Low expression |
| MCF7 | 1.2 | Low expression |
| A549 | 0.3 | Not detected |
| K562 | 0.1 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.101G>A (p.Arg34His) | Missense | <0.01% | Reported in hearing loss; may impair channel function |
| c.205C>T (p.Pro69Ser) | Missense | <0.01% | Unknown significance; predicted damaging |
| c.457G>A (p.Val153Met) | Missense | <0.01% | Unknown significance |
Mutation functional classification
Loss of Function (LOF)
Missense variants (e.g., p.Arg34His) are predicted to disrupt connexin assembly or channel gating, leading to loss of gap junction function.
Gain of Function (GOF)
No gain-of-function mutations have been reported for GJD4.
Dominant Negative (DN)
Some connexin mutants can exert dominant-negative effects by co-assembling with wild-type connexins; not specifically documented for GJD4.
View complete mutation data：
Gene Ontology (GO)
| • connexin complex (GO:0005922) | • cell communication (GO:0007154) |
| • gap junction assembly (GO:0016264) | • gap junction channel activity (GO:0005243) |
| • plasma membrane (GO:0005886) |
Pathways
• Gap junction trafficking and regulation (Reactome: R-HSA-190828)
• Gap junction assembly (Reactome: R-HSA-190861)
Protein Summary
Connexin 40.1 (Cx40.1) is a 346-amino acid transmembrane protein with four transmembrane domains, two extracellular loops, and cytoplasmic N- and C-termini. It forms hexameric hemichannels that dock with hemichannels on adjacent cells to create gap junction channels. Cx40.1 is involved in electrical and metabolic coupling, and its expression is regulated in a tissue-specific manner. Structural modeling suggests conserved residues critical for channel selectivity and gating.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GJD4 Knockout HEK293 Cell Line | EDJ-KQ8326 | Human | 219770 | Details Get a Quote |
| GJD4 Knockout HeLa Cell Line | EDJ-KQ59099 | Human | 219770 | Details Get a Quote |
| GJD4 Knockout A-549 Cell Line | EDJ-KQ67573 | Human | 219770 | Details Get a Quote |
| GJD4 Knockout HCT 116 Cell Line | EDJ-KQ75965 | Human | 219770 | Details Get a Quote |
