### PKP4 Gene Overview

**Gene Symbol**: PKP4  
**Gene Type**: Protein-coding  
**Location**: Human chromosome 8

### Protein Structure and Function
PKP4 is a member of the plakophilins family of proteins which are characterized by the presence of armadillo repeats, a structural motif that facilitates protein-protein interactions. Plakophilins are known to play a crucial role in cell-cell adhesion, particularly in desmosomes, as well as in regulating the cytoskeleton, which is critical during cell migration and division (cytokinesis). 

PKP4 is believed to modulate junctional plaque organization and influence cadherin function, thereby contributing to the structural integrity of tissues, particularly in epithelial cells.

### Additional Associated Genes
While the summaries mention several key members of the same gene family (e.g., PKP1, PKP2, and others), PKP4 may also be associated with genes involved in similar pathways or complexes, such as:
- **CTNND1**: Catenin delta (plakophilin-associated)
- **ARVCF**: Armadillo repeat containing, X-linked
- **DSG1, DSG2, DSG3, and DSG4**: Desmogleins that are crucial for desmosomal adhesion.

### Aging and Age-related Disease Associations
Currently, there are limited specific studies directly implicating PKP4 in aging or age-related diseases. However, its role in cell adhesion and integrity connects it to processes such as tissue remodeling and cancer progression:
- **Cardiac Integrity**: Alterations in desmosomal proteins have been associated with cardiomyopathies which are more prevalent in aging populations.
- **Skin Aging and Epithelial Integrity**: PKP4's involvement in desmosomal structures could suggest a role in age-related changes in skin and epithelial tissue integrity.

### Drug Interactions
As of the latest updates, there are no specific drugs directly targeting PKP4. However, it may interact indirectly through signaling pathways or processes regulated by:
- **Rho GTPase inhibitors**: Since PKP4 is known to regulate Rho activity, drugs affecting the Rho signaling pathway may have implications on how PKP4 functions during cytokinesis and cell adhesion.

### Pathways and Biological Processes
PKP4 is involved in several crucial biological processes, including:
- **Cell adhesion**: Contributing to desmosome and junction formation.
- **Cytokinesis**: Regulation of Rho GTPase signaling during cell division.
- **Signal transduction**: Interacting with cadherins and potentially influencing cellular responses to external cues.

**Key Pathways**:
- **Cadherin signaling pathway**
- **Rho GTPase signaling pathway**
- **Cell junction organization**

### Conclusion
PKP4 plays a significant role in maintaining cellular architecture and function through its interactions in desmosomes and junctional plaques. While there may be emerging studies in the context of age-related conditions or specific drug interactions, direct connections remain an ongoing area of research.