### PRPSAP2 Gene Overview
**Gene Symbol:** **PRPSAP2**  
**Function:** The PRPSAP2 gene encodes a non-catalytic associated subunit of phosphoribosylpyrophosphate synthetase (PRS). PRS plays a crucial role in the de novo synthesis of purine and pyrimidine nucleotides, as well as in histidine, tryptophan, and NAD biosynthesis. The PRPSAP2 protein acts as a negative regulator of 5-phosphoribose 1-diphosphate synthesis, thereby potentially influencing metabolic pathways associated with nucleotide synthesis.

### 1. Related Genes
PRPSAP2 is associated with:
- **PRPS1 (Phosphoribosylpyrophosphate synthetase 1):** The primary catalytic subunit of PRS, directly involved in the synthesis of phosphoribosylpyrophosphate.
- **PRPS2 (Phosphoribosylpyrophosphate synthetase 2):** A second PRS isoform which also contributes to nucleotide metabolism.
- **Other related metabolic genes:** These may include genes involved in the purine and pyrimidine metabolism pathways, such as those coding for enzymes downstream of PRS.

### 2. Aging and Age-Related Diseases
Research on PRPSAP2 specifically in the context of aging or age-related diseases is limited, but its role in nucleotide synthesis could suggest potential implications:
- **Cellular Aging:** The energetic and molecular requirements for cell maintenance during aging provoke a significant demand for nucleotide metabolism. Disruption of PRS activity could lead to altered cellular processes, contributing to aging.
- **Implications in Cancer:** Altered purine metabolism is a hallmark of various cancers, possibly linking PRPSAP2 to tumorigenesis due to its regulation of nucleotide synthesis.
- **Neurodegenerative Diseases:** Some studies suggest a connection between nucleotide metabolism and neurodegeneration, opening avenues for further investigation into PRPSAP2’s role in these conditions.

### 3. Drug Interactions
While specific drugs directly targeting PRPSAP2 are not well-documented, it is essential to consider:
- **Nucleotide Synthesis Modulators:** Drugs impacting PRS activity indirectly might affect PRPSAP2 function. For example, agents such as nucleotide analogs or inhibitors affecting purine metabolism may demonstrate interactions.
- **Antimetabolites:** As PRPSAP2 influences metabolic pathways integral for cell proliferation, class of drugs like methotrexate (which targets folate metabolism) could be relevant.

### 4. Pathways and Biological Processes
**Biological Processes:**
- **Purine Metabolism:** PRPSAP2 is critical in the purine biosynthesis pathway, playing a regulatory role in nucleotide levels.
- **Nucleotide Metabolic Process:** It is involved in the overall nucleotide metabolism and related metabolic pathways, influencing various biosynthetic pathways essential for cell viability and proliferation.
  
**Pathways:**
- **De Novo Purine Biosynthesis:** PRPSAP2's function in regulating PRS directly impacts this pathway, crucial for synthesizing ATP and GTP.
- **Nucleotide Salvage Pathways:** Though less directly involved, its association with PRS indicates a supporting role in recycling nucleotides.
  
In summary, the PRPSAP2 gene serves a key regulatory function in nucleotide metabolism by modulating the activity of PRS, with potential implications for aging and diseases characterized by disrupted nucleotide synthesis. Further research could elucidate its role in health and disease, especially regarding its associations with aging and various therapeutic avenues.