TMEM218: Transmembrane Protein 218
A gene encoding a transmembrane protein with potential roles in ciliary function and associated with retinal and renal disorders.
Gene Information Card
| Symbol | TMEM218 |
|---|---|
| Full Name | Transmembrane Protein 218 |
| Gene Type | Protein coding |
| Chromosomal Location | 11q24.2 |
| NCBI Gene ID | 219854 ncbi.nlm.nih.gov/gene/219854 |
| Ensembl ID | ENSG00000180209 |
| UniProt ID | Q8N8L9 |
| OMIM ID | 620067 |
| HGNC ID | 28497 |
| Aliases | MGC35130, FLJ23577 |
Description
TMEM218 encodes a transmembrane protein of unknown function. It is predicted to be a component of the ciliary membrane and is implicated in ciliopathies. Mutations in TMEM218 have been associated with Joubert syndrome and related disorders, including nephronophthisis and retinal dystrophy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Joubert syndrome | Loss of TMEM218 function disrupts ciliary signaling, leading to cerebellar and retinal defects. | OMIM #620067; PMID: 32502799 |
| Nephronophthisis | TMEM218 mutations impair renal cilia function, causing cystic kidney disease. | ClinVar; PMID: 32502799 |
| Retinal dystrophy | Defective TMEM218 in photoreceptor cilia leads to progressive vision loss. | OMIM #620067; PMID: 32502799 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 8.2 | Medium |
| Kidney | 5.1 | Low |
| Retina | 4.3 | Low |
| Brain | 3.0 | Low |
| Lung | 2.5 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 6.0 | Moderate expression in kidney-derived cells |
| ARPE-19 | 4.5 | Retinal pigment epithelium cell line |
| HepG2 | 2.0 | Low expression in liver cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon, likely loss of function |
| c.325C>T (p.Arg109*) | Nonsense | Rare | Premature stop, loss of function |
| c.494G>A (p.Trp165*) | Nonsense | Rare | Premature stop, loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense and start-loss mutations lead to truncated or absent protein, causing ciliary dysfunction.
Gain of Function (GOF)
No evidence of gain-of-function mutations.
Dominant Negative (DN)
No evidence of dominant-negative effects.
View complete mutation data：
Gene Ontology (GO)
| • protein binding (GO:0005515) | • integral component of membrane (GO:0016021) |
| • ciliary basal body (GO:0036064) | • cilium assembly (GO:0060271) |
Pathways
• Cilium assembly and maintenance (Reactome: R-HSA-5617833)
• Signaling by Hedgehog (Reactome: R-HSA-5358351)
Protein Summary
TMEM218 is a 218-amino acid transmembrane protein with two predicted transmembrane domains. It localizes to the ciliary membrane and is essential for proper ciliary function. Loss of TMEM218 disrupts ciliary signaling, leading to ciliopathy phenotypes such as Joubert syndrome, nephronophthisis, and retinal dystrophy.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TMEM218 Knockout HEK293 Cell Line | EDJ-KQ8388 | Human | 219854 | Details Get a Quote |
| TMEM218 Knockout HCT 116 Cell Line | EDJ-KQ33115 | Human | 219854 | Details Get a Quote |
| TMEM218 Knockout A-549 Cell Line | EDJ-KQ34449 | Human | 219854 | Details Get a Quote |
| TMEM218 Knockout HeLa Cell Line | EDJ-KQ34451 | Human | 219854 | Details Get a Quote |
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