### GMPPA Gene Overview

**Gene Symbol**: GMPPA  
**Description**: The GMPPA gene encodes GDP-mannose pyrophosphorylase, an enzyme critical for the biosynthesis of GDP-mannose from mannose-1-phosphate and GTP. GDP-mannose is pivotal for the production of N-linked oligosaccharides, which play essential roles in glycosylation processes within cells.

### 1. Associated Genes
The GMPPA gene may have associations with several other genes involved in glycosylation and carbohydrate metabolism. These may include:
- **GMPPB**: This gene encodes another GDP-mannose pyrophosphorylase and appears to function in parallel with GMPPA. It has been noted that GMPPA may serve as a regulatory subunit for GMPPB.
- **GMPPC**: Another related gene encoding a similar protein that is thought to function in GDP-mannose synthesis but was less studied.
- **Mannose-6-phosphate isomerase (MPI)**: Involved in the metabolic pathway that includes mannose conversion.
- **Genes involved in N-linked glycosylation processes**: Such as the OGGT (O-linked β-N-acetylglucosamine transferase) and other glycosyltransferases involved in oligosaccharide biosynthesis.

### 2. Aging and Age-Related Diseases
While direct associations between GMPPA and aging or age-related diseases may not be extensively characterized, glycosylation processes, where GDP-mannose is crucial, have been implicated in various age-related conditions:
- **Altered Glycosylation**: Changes in glycosylation patterns are often observed in aging and can affect immune function, cell signaling, and the progress of age-related diseases.
- **Potential Associations with Metabolic Disorders**: Impairments in mannose metabolism may contribute to disorders such as diabetes, which are prevalent in older populations.

### 3. Drug Interactions
Currently, there may not be specific drugs directly interacting with the GMPPA gene product noted in literature; however, there may be implications in:
- **Glycosylation-inhibiting drugs**: Such as tunicamycin, which affect processes of glycosylation and may indirectly relate to GMPPA function.
- **Regulatory compounds affecting carbohydrate metabolism**: Any drugs affecting pathways involving GDP-mannose, possibly affecting cellular glycosylation mechanisms.

### 4. Pathways and Biological Processes
**Pathways**:  
- **N-glycan biosynthesis**: This pathway highlights the importance of GDP-mannose in synthesizing N-linked glycoproteins.
- **Glycosaminoglycan biosynthesis**: For the synthesis of essential extracellular matrix components.
- **Mannose metabolism**: Associated with various metabolic pathways centered on monosaccharides.

**Biological Processes**:
- **Glycoprotein biosynthesis**: The product of GMPPA is vital for the synthesis of glycoproteins, affecting cell surface properties, signaling, and immune recognition.
- **Cellular signaling**: Through contributions to glycosylation of proteins and lipids, influencing numerous signaling pathways.
- **Metabolic processes**: Involvement in the carbohydrate metabolic pathways linking to energy storage and utilization mechanisms.

### Conclusion
The GMPPA gene plays a key role in the synthesis of GDP-mannose, which is fundamental in glycosylation. Its relationship with other genes and pathways highlights its importance in cellular functions and potential links to aging and various diseases, although more research may be needed to uncover specific roles in pathologies and drug interactions.