### MT3 Gene Overview

**Gene Symbol:** MT3  
**HGNC ID:** 7136  

#### 1. Associated Genes
The MT3 gene is often studied in relation to other genes involved in metal ion homeostasis and neurodegeneration. Some of these include:

- **MT1, MT2:** Other members of the metallothionein gene family.
- **SOD1:** Encodes superoxide dismutase, an antioxidant enzyme that protects against oxidative stress, which may be influenced by metal ion levels.
- **APP:** Amyloid precursor protein; associated with Alzheimer's disease and may interact with copper and zinc ion regulation.
- **PRNP:** The prion protein gene, which is involved in neurodegenerative diseases and metal ion interaction.

#### 2. Aging and Age-Related Diseases
Research indicates that MT3 plays a significant role in the brain's response to oxidative stress and metal ion balance. Changes or reductions in MT3 levels have been observed in neurodegenerative disorders, particularly related to aging:

- **Alzheimer's Disease:** Reduced levels of MT3 in the brains of Alzheimer’s patients suggest a role in neuroprotective mechanisms and possibly in the regulation of amyloid plaques.
- **Age-Related Macular Degeneration (AMD):** While direct associations may not be as well characterized, altered metal homeostasis is a common theme in AMD.
- **General Aging:** Dysregulation of metallothioneins has been implicated in cellular stress responses that are characteristic of aging processes.

#### 3. Drug Interactions
While direct drug interactions specifically targeting MT3 are limited, certain classes of drugs affecting metal ion homeostasis or neuroprotection may indirectly influence the activity of this gene:

- **Zinc supplements:** Can influence MT3 expression and metal ion balance.
- **Antioxidants:** Drugs or compounds that reduce oxidative stress may impact the expression or function of metallothioneins.
- **Cholinergic drugs:** Related to neuroprotective strategies in Alzheimer's that may indirectly involve metal regulation.

#### 4. Pathways and Biological Processes
The MT3 gene is involved in various critical biological pathways and processes, including:

- **Metal Ion Binding:** Particularly with zinc and copper, which is significant for neuronal health.
- **Cellular Response to Hypoxia:** MT3 expression is induced under low oxygen conditions, suggesting a role in cellular adaptation and survival.
- **Neuroprotection:** Inhibitory effects on neuronal survival and neurite outgrowth highlight its potential role in neuronal health and development.
- **Cellular Stress Response:** Involvement in responses to oxidative and metallic stress, crucial for maintaining cellular integrity during aging and disease pathology.

### Summary
The MT3 gene is a unique member of the metallothionein family engaged in heavy metal ion binding and is implicated in neuroprotection, particularly concerning aging and neurodegenerative diseases such as Alzheimer's. Its interactions with other genes related to metal homeostasis and cellular stress responses underscore its biological significance.