### Overview of the MPP3 Gene

**Gene Symbol:** MPP3  
**Location:** Chromosome 21 (human)

**Function and Structure:**  
The MPP3 gene encodes a protein that is part of the MAGUK (membrane-associated guanylate kinase homologs) family of proteins. These proteins are known for their role in linking cell surface proteins with the cytoskeleton and are integral to various cellular processes including cell signaling, cell adhesion, and the maintenance of cellular structures. MPP3 contains an SH3 (src homology 3) domain, which is involved in protein-protein interactions and signal transduction pathways.

### 1. Associated Genes
While the NCBI and UniProt summaries primarily mention CADM1 and DLG1 as partners in specific pathways, MPP3's interactions generally extend to various proteins in the MAGUK family such as:
- **DLG1** (Disks-Large Homolog 1)
- **PSD-95** (Postsynaptic Density Protein 95)
- **CSV (CASK)**, which is part of the complex at synapses.
- Interactions with other cytoskeletal and signaling proteins may include:

  - **Rho GTPases** (known to be important in cytoskeletal dynamics).
  - **PIK3R1** (regulatory subunit of PI3K).

### 2. Aging and Age-Related Diseases
Although there are no direct records specifically linking MPP3 to aging or well-defined age-related diseases in the literature, disruptions in MAGUK proteins are often associated with:
- **Neurodegenerative Disorders:** Potentially, through mechanisms affecting synaptic function and plasticity.
- **Age-related diseases such as Alzheimer's Disease:** Given that MAGUKs are involved in maintaining synaptic integrity, there could be indirect implications.

### 3. Drug Interactions
While specific drugs are not regularly characterized for direct interaction with MPP3, proteins involved in similar pathways, such as those targeting PI3K signaling (e.g., **PI3K inhibitors** or agonists) may indirectly affect functions related to MPP3. It is important to consider:
- **Phosphoinositide 3-kinase inhibitors**, which may modulate pathways that MPP3 participates in.
- Potential research into **psychoactive drugs** affecting serotonin receptor activity, since MPP3 stabilizes HTR2C receptors.

### 4. Pathways and Biological Processes
MPP3 has been implicated in several key biological processes:
- **Cell adhesion and junction maintenance:** It plays a crucial role in stabilizing adherens junctions critical for cellular morphology.
- **Cell spreading and migration:** Involvement through the PI3K signaling pathway highlights its role in cytoskeletal reorganization.
- **Neuronal signaling:** Given its interaction with synaptic proteins, it likely contributes to synaptic transmission and plasticity.
- **Signal transduction:** Through its interactions with other signaling molecules, MPP3 is involved in pathways that manage cellular responses to stimuli.

### Conclusion
The MPP3 gene plays a multifaceted role in cellular function, particularly through its involvement in cell signaling, adhesion, and synaptic integrity. Further research may elucidate more specific relationships with aging and disease, while the exploration of pharmacological interactions remains an intriguing area for potential therapies.