AMBN (Ameloblastin) Gene
Key Enamel Matrix Protein in Tooth Development and Amelogenesis Imperfecta
Gene Information Card
| Symbol | AMBN |
|---|---|
| Full Name | Ameloblastin |
| Gene Type | protein-coding |
| Chromosomal Location | 4q13.3 |
| NCBI Gene ID | 258 ncbi.nlm.nih.gov/gene/258 |
| Ensembl ID | ENSG00000138614 |
| UniProt ID | Q9NP70 |
| OMIM ID | 601259 |
| HGNC ID | 452 |
| Aliases | ALBN, AMBN_HUMAN, AI1E, AI1I, AI1J |
Description
The AMBN gene encodes ameloblastin, a non-amelogenin enamel matrix protein secreted by ameloblasts during tooth development. Ameloblastin is critical for enamel formation, mineralization, and structural integrity. Mutations in AMBN are associated with autosomal dominant and recessive forms of amelogenesis imperfecta, a disorder characterized by defective enamel.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Amelogenesis Imperfecta Type 1E (AI1E) | Loss-of-function mutations in AMBN disrupt enamel matrix assembly, leading to hypoplastic enamel. | OMIM #614832 |
| Amelogenesis Imperfecta Type 1I (AI1I) | Missense or nonsense mutations impair ameloblastin secretion or function, causing enamel defects. | OMIM #616270 |
| Amelogenesis Imperfecta Type 1J (AI1J) | Compound heterozygous or homozygous mutations result in severe enamel hypoplasia. | OMIM #617297 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Salivary gland | 0.0 | Not detected |
| Thyroid | 0.0 | Not detected |
| Testis | 0.0 | Not detected |
| Tooth (enamel organ) | High (qualitative) | High (specific to ameloblasts) |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| LS8 (mouse ameloblast-like) | N/A | Model for enamel matrix secretion |
| Hela | 0.0 | No expression |
| HEK293 | 0.0 | No expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense/start loss | Rare | Loss of translation initiation |
| c.131C>T (p.Pro44Leu) | Missense | Unknown | Reduced protein stability |
| c.208C>T (p.Arg70*) | Nonsense | Rare | Premature truncation, loss of function |
| c.334G>A (p.Gly112Arg) | Missense | Unknown | Impaired secretion |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations leading to truncated or absent ameloblastin protein, causing hypoplastic enamel.
Gain of Function (GOF)
Not reported for AMBN.
Dominant Negative (DN)
Missense mutations that disrupt protein folding or secretion, interfering with wild-type ameloblastin function in heterozygous state.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Enamel formation (Reactome: R-HSA-1474244)
• Extracellular matrix organization (Reactome: R-HSA-1474244)
Protein Summary
Ameloblastin is a 447-amino acid secreted protein (UniProt Q9NP70) that constitutes about 5% of the enamel matrix. It undergoes proteolytic processing to generate bioactive fragments that regulate ameloblast adhesion, enamel crystal growth, and mineralization. The protein contains a signal peptide (residues 1-16) and multiple phosphorylation sites. Defects in ameloblastin lead to enamel hypoplasia and are linked to several forms of amelogenesis imperfecta.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| AMBN Knockout HEK293 Cell Line | EDJ-KQ4050 | Human | 258 | Details Get a Quote |
| AMBN Knockout HeLa Cell Line | EDJ-KQ52603 | Human | 258 | Details Get a Quote |
| AMBN Knockout A-549 Cell Line | EDJ-KQ61083 | Human | 258 | Details Get a Quote |
| AMBN Knockout HCT 116 Cell Line | EDJ-KQ69565 | Human | 258 | Details Get a Quote |
