### PEX2 Gene Overview

**Gene Symbol:** PEX2  
**Chromosomal Location:** Human chromosome 8q21.11  

**Function:** 
The PEX2 gene encodes an integral peroxisomal membrane protein that is crucial for peroxisome biogenesis. It acts as a component of the E3 ubiquitin ligase complex and is involved in the retrotranslocation of the PEX5 receptor from the peroxisome back to the cytosol, facilitating its recycling. It also promotes peroxisome organization through the ubiquitination of various peroxisomal proteins.

### 1. Associated Genes
In addition to PEX2, several other genes are known to be associated, especially those that are part of the peroxisome biogenesis pathway and functionally linked to PEX2, which include:
- **PEX5**: A receptor for peroxisomal matrix proteins that PEX2 interacts with for recycling.
- **PEX10**: Another component of the retrotranslocation channel together with PEX2.
- **PEX12**: Works in concert with PEX2 and PEX10.
- **ABCD3 (PMP70)**: Involved in the import of fatty acids into the peroxisome and serves as a substrate for PEX2-mediated ubiquitination.
- **PNPLA2 (ATGL)**: A target for ubiquitination, affecting lipid metabolism.

### 2. Aging and Age-Related Diseases
- **Zellweger Syndrome** and **Infantile Refsum Disease**: Mutations in PEX2 lead to these conditions, characterized by peroxisomal dysfunction, which can present with various neurodegenerative symptoms that relate to aging.
- **Reactive Oxygen Species (ROS)**: PEX2’s role in mediating responses to ROS suggests a connection to cellular damage and aging. Dysregulated ROS management is a contributor to age-related diseases including neurodegeneration and metabolic disorders.
- **Pexophagy**: The role of PEX2 in pexophagy (degradation of peroxisomes) is particularly relevant to aging as dysfunctional organelles accumulate with age, impacting cellular homeostasis.

### 3. Drug Interactions
Currently, no specific drugs or drug classes targeting PEX2 have been established, but research into modulators of peroxisome biogenesis and function could potentially implicate PEX2 indirectly. Given its role in ubiquitination and protein degradation, studies could explore inhibitors of the ubiquitin-proteasome system or compounds that modulate peroxisome function for therapeutic applications.

### 4. Pathways and Biological Processes
The PEX2 gene is involved in several key biological processes and pathways:
- **Peroxisome Biogenesis**: Essential for the formation and maintenance of functional peroxisomes.
- **Ubiquitin-Proteasome System**: Functions as an E3 ubiquitin ligase, mediating the ubiquitination of substrates.
- **Response to Stress**: Involvement in the cellular response to oxidative stress and starvation by regulating pexophagy and ubiquitin-mediated degradation of damaged proteins.
- **Lipolysis Regulation**: Through its action on PNPLA2, it plays a role in lipid metabolism and energy homeostasis.

### Summary
The PEX2 gene is integral to peroxisomal function and metabolism. Through its roles in ubiquitination, receptor recycling, and response to cellular stress, it is essential for maintaining cellular health, especially in the context of aging and age-related diseases. Further research is necessary to explore its potential in drug development targeting peroxisome-related disorders.