### PPP4R4 Gene Overview

**Gene Symbol:** PPP4R4  
**Function:** Encodes a protein that serves as a putative regulatory subunit of protein serine/threonine phosphatase 4 (PP4). Its HEAT-like repeats enable it to participate in protein-protein interactions, potentially modulating the activity of PP4 and influencing various cellular processes.

### 1. Associated Genes
The PPP4R4 gene is associated with several other genes, particularly those involved in similar cellular processes or pathways. Notably:
- **PPP4C:** This gene encodes the catalytic subunit of protein phosphatase 4 and directly interacts with PPP4R4.
- **PPP2R** family genes (like PPP2R1A and PPP2R2A): These genes encode regulatory subunits of another serine/threonine phosphatase, protein phosphatase 2A (PP2A), which share functional similarities with PP4 and may interact in various signaling pathways.
- **AKT1:** While not directly associated, AKT signaling is often regulated by phosphatases like PP4, and PPP4R4 may indirectly influence AKT-related pathways.

### 2. Aging and Age-Related Diseases
The direct role of PPP4R4 in aging or age-related diseases is not well characterized. However, because protein phosphatases are involved in many cellular processes, including those related to cell cycle regulation and stress responses:
- Alterations in serine/threonine phosphatase activities have been linked to aging processes.
- Some studies suggest that dysregulation of phosphatases, including PP4 (which PPP4R4 regulates), may play a role in age-related cognitive decline and neurodegenerative diseases.

### 3. Drug Interactions
While there are currently no specific drugs directly targeting PPP4R4, its involvement in PP4 signaling pathways suggests that:
- **Phosphatase inhibitors:** Drugs that inhibit serine/threonine phosphatases may indirectly affect the activity of PPP4R4, as it regulates PP4.
- Drug classes that may functionally relate to pathways involving PPP4R4 include oncological drugs used to target cancers where PP4 activity has been implicated.

### 4. Pathways and Biological Processes
PPP4R4 is involved in several biological processes and signaling pathways:
- **Cell Cycle Regulation:** By interacting with PP4, PPP4R4 may contribute to cell cycle control, particularly in mitosis.
- **DNA Repair:** PPP4 is known to be involved in DNA damage response, and thus PPP4R4 may contribute to cellular mechanisms that repair DNA.
- **Signal Transduction Pathways:** It is engaged in various signaling cascades where phosphorylation states are critical, including those driven by growth factors and stress responses.
- **Developmental Processes:** The regulation of phosphatases is crucial in developmental signaling, suggesting a role of PPP4R4 during embryonic development.

### Conclusion
The PPP4R4 gene encodes a protein that is part of a critical regulatory complex for protein phosphatase 4. While specific drug interactions and aging-related functions are still being elucidated, the role of PPP4R4 in cellular signaling implicated in development, the cell cycle, and DNA repair highlights its significance in biological processes. Further studies are needed to better understand its associations and impacts in aging and disease contexts.