### ATP7B Gene Overview

**Gene Symbol:** ATP7B  
**Location:** Chromosome 13 (13q14.3)  
**Gene Type:** Protein-coding

**Function:**  
The ATP7B gene encodes a copper-transporting ATPase that plays a crucial role in maintaining copper homeostasis within the liver. It primarily functions by exporting excess copper from the hepatocytes into the bile, which helps to prevent copper accumulation in tissues. This process is vital for preventing toxicity associated with copper overload.

### Additional Gene Associations
ATP7B has been associated with several other genes, particularly in relation to copper metabolism and related disorders. Some notable associations include:

- **ATP7A:** Another P-type cation transport ATPase involved in copper transport, primarily in the intestine.
- **COMMD1:** A gene that may influence the expression and function of copper transporters, including ATP7B.
- **MURR1 (COMMD9):** Interacts with ATP7B and may affect its function relating to copper homeostasis.
- **SLC31A1 (CTR1):** A copper transporter that, although primarily responsible for copper uptake, functions in conjunction with ATP7B in maintaining copper balance.

### Age-Related Details
Although ATP7B is directly involved in the pathology of Wilson disease, there are implications of copper metabolism in aging and age-related diseases:

- **Neurodegenerative Diseases:** Copper imbalance has been suggested to play a role in neurodegenerative conditions, such as Alzheimer's disease, where copper accumulation may result in oxidative stress and neurodegeneration.
- **Liver Disorders:** Accumulation of copper due to impaired ATP7B function can contribute to liver dysfunction, potentially exacerbating age-related liver diseases.
- **Oxidative Stress:** Increased copper levels may lead to heightened oxidative stress, which has been associated with the aging process and age-related diseases.

### Drug Interactions
Several drugs and drug classes interact indirectly or are used to manage conditions related to ATP7B mutations, especially in Wilson disease:

- **Penicillamine:** A chelating agent used to treat Wilson disease by binding free copper for excretion.
- **Trientine:** Another chelating agent that serves as an alternative treatment for Wilson disease.
- **Zinc Acetate:** Used to reduce copper absorption in the gastrointestinal tract, thereby decreasing overall copper levels in individuals with Wilson disease.
- **Antioxidants:** Some antioxidants may be investigated for their potential benefit in mitigating copper-induced oxidative stress.

### Pathways and Biological Processes
ATP7B is involved in various biological pathways and processes, including:

- **Copper Ion Transport:** Essential for the transmembrane movement of copper ions, actively transporting it out of cells.
- **Copper Homeostasis:** Plays a critical role in maintaining cellular and systemic copper levels, preventing toxicity.
- **Metallostasis:** Part of the broader processes of maintaining metal ion balance in the body.
- **Endosomal Transport:** Involved in the regulation of copper levels within intracellular compartments.

In terms of biological pathways, ATP7B is part of pathways associated with disease mechanisms such as Wilson disease and other disorders of metal metabolism.

### Summary
ATP7B is essential for copper transport and homeostasis, particularly in hepatocytes, playing an important role in preventing copper accumulation and associated toxicity. Its interactions with other genes and implications in age-related diseases emphasize the significance of maintaining copper balance for healthy aging.