MT3 (Metallothionein 3)
A neuronal growth inhibitory factor involved in zinc homeostasis and neurodegeneration
Gene Information Card
| Symbol | MT3 |
|---|---|
| Full Name | Metallothionein 3 |
| Gene Type | protein-coding |
| Chromosomal Location | 16q13 |
| NCBI Gene ID | 4504 ncbi.nlm.nih.gov/gene/4504 |
| Ensembl ID | ENSG00000187134 |
| UniProt ID | P25713 |
| OMIM ID | 139255 |
| HGNC ID | 7433 |
| Aliases | GIF, GIFB, ZnMT3 |
Description
MT3 encodes metallothionein 3, a cysteine-rich protein that binds heavy metals such as zinc and copper. It is primarily expressed in the brain and acts as a growth inhibitory factor (GIF) for neurons. MT3 plays a key role in zinc homeostasis, protection against oxidative stress, and regulation of neuronal survival. Dysregulation of MT3 is implicated in Alzheimer disease and other neurodegenerative disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Alzheimer Disease | Reduced MT3 expression leads to impaired zinc buffering and increased amyloid-beta aggregation, contributing to neurotoxicity. | PMID: 10428034, 15689449 |
| Amyotrophic Lateral Sclerosis | Altered MT3 levels in spinal cord motor neurons may affect zinc homeostasis and oxidative stress response. | PMID: 15987639 |
| Brain Neoplasms | MT3 expression is downregulated in glioblastoma, potentially affecting tumor growth and invasion. | PMID: 19177216 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | High |
| Testis | 2.1 | Low |
| Kidney | 1.8 | Low |
| Liver | 0.5 | Not detected |
| Heart | 0.3 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 8.4 | Neuronal model; high MT3 expression |
| U-87 MG (glioblastoma) | 1.2 | Low expression compared to normal brain |
| HEK293 (embryonic kidney) | 0.6 | Very low endogenous expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1Val) | missense | <0.01% | Start codon loss; predicted loss of function |
| c.205C>T (p.Arg69Cys) | missense | <0.01% | Alters zinc-binding capacity; associated with altered neuronal growth inhibition |
Mutation functional classification
Loss of Function (LOF)
Mutations affecting start codon or zinc-binding cysteines reduce MT3's ability to sequester zinc, leading to impaired neuroprotection.
Gain of Function (GOF)
Not described in literature.
Dominant Negative (DN)
Not described in literature.
View complete mutation data：
Gene Ontology (GO)
| • zinc ion binding (GO:0008270) | • metal ion binding (GO:0046872) |
| • response to zinc ion (GO:0010043) | • response to drug (GO:0042493) |
| • apoptotic process (GO:0006915) | • response to estradiol (GO:0032355) |
Pathways
• Metallothionein bind metals (REACT_25056)
• Zinc homeostasis (REACT_25057)
Protein Summary
Metallothionein 3 (MT3) is a 68-amino acid protein with 20 cysteine residues that coordinate 7 zinc ions. It is predominantly expressed in the brain, particularly in astrocytes and neurons. MT3 inhibits neuronal growth and protects against zinc-mediated neurotoxicity. Its expression is reduced in Alzheimer disease brains, contributing to amyloid plaque formation and oxidative damage.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MT3 Knockout HEK293 Cell Line | EDJ-KQ5250 | Human | 4504 | Details Get a Quote |
| MT3 Knockout HeLa Cell Line | EDJ-KQ53915 | Human | 4504 | Details Get a Quote |
| MT3 Knockout A-549 Cell Line | EDJ-KQ62408 | Human | 4504 | Details Get a Quote |
| MT3 Knockout HCT 116 Cell Line | EDJ-KQ70875 | Human | 4504 | Details Get a Quote |
