### GPX3 Gene Overview

**Gene Name:** GPX3  
**Gene Symbol:** GPX3 (Glutathione Peroxidase 3)  
**Chromosomal Location:** Human Chromosome 5q33.1

**Protein Function:**  
The GPX3 gene encodes the enzyme glutathione peroxidase 3, which plays a pivotal role in cellular antioxidant defense by catalyzing the reduction of hydrogen peroxide, organic hydroperoxides, and lipid peroxides using glutathione as a substrate. This protein is secreted and abundant in the plasma, reflecting its significant role in protecting extracellular spaces from oxidative stress.

**Key Features:**
- **Selenoprotein:** GPX3 contains selenocysteine (Sec) at its active site, which is crucial for its enzymatic activity. The incorporation of selenocysteine is facilitated by a conserved SECIS element in the mRNA.
- **Isoforms:** Multiple alternatively spliced transcript variants of GPX3 have been identified, which may exhibit variations in their functionality and regulation.

### 1. Associated Genes

While the provided summaries mention GPX3's involvement in several malignancies, potential associations with other oxidative stress-related genes may include:
- **GPX1 (Glutathione Peroxidase 1)**: Involved in intracellular antioxidant defense.
- **SOD (Superoxide Dismutase) Genes**: Including SOD1 and SOD2, which are important for converting superoxide radicals to hydrogen peroxide.
- **CAT (Catalase)**: Enzyme that catalyzes the decomposition of hydrogen peroxide.
- **GSR (Glutathione Reductase)**: Helps maintain the antioxidant function of glutathione.

### 2. Aging and Age-Related Diseases

Research has indicated that GPX3 may play a role in aging and the development of age-related diseases:
- **Oxidative Stress:** As GPX3 is involved in neutralizing reactive oxygen species, its downregulation may contribute to increased oxidative stress, which has been implicated in aging processes.
- **Chronic Diseases:** Reduced levels of GPX3 have been associated with various age-related diseases, including neurodegenerative diseases, cardiovascular diseases, and forms of cancer.
- **Longevity:** Some studies suggest that the activity of antioxidant enzymes like GPX3 may correlate with lifespan and healthier aging.

### 3. Drug/Drug Classes Interacting with GPX3

There is limited specific information about drugs that directly interact with GPX3. However, the following categories may have influences:
- **Antioxidants:** Nutraceuticals such as selenium supplements, which are vital for the function of many selenoproteins, including GPX3.
- **Chemotherapeutic Agents:** Certain chemotherapy drugs can affect cellular oxidative stress and might influence the expression of antioxidant enzymes, including GPX3.
- **Inflammation Modulators:** Drugs that modulate inflammation may indirectly affect GPX3 expression due to their impact on oxidative stress levels.

### 4. Pathways and Biological Processes

GPX3 is involved in several critical biological processes and pathways:
- **Oxidative Stress Response:** Catalyzes the reduction of hydrogen peroxide and organic peroxides, mitigating oxidative damage and maintaining redox balance.
- **Detoxification of Reactive Oxygen Species (ROS):** Plays a direct role in neutralizing harmful ROS.
- **Selenium Metabolism:** GCCP3 interacts with metabolic processes that involve selenium, influencing various selenoproteins' biosynthesis.
- **Cell Signaling:** It may indirectly affect signaling pathways related to cell proliferation, apoptosis, and inflammation through its modulation of oxidative stress.

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This comprehensive overview synthesizes the information about GPX3, highlighting its functional significance, associations with other genes, relevance in aging and disease processes, drug interactions, and biological pathways.