The **PRKAR2A** gene encodes the regulatory subunit type II-alpha of cAMP-dependent protein kinase (PKA), which plays a critical role in cellular signaling mechanisms through its regulation of cAMP levels. Below are detailed insights regarding the gene along with the requested specific information:

### 1. Associated Genes
- **PRKCA** (Protein Kinase C Alpha): Since cAMP can influence the PKC pathway, PRKAR2A may interact indirectly with many pathways involving PRKCA.
- **AKAPs (A-kinase anchoring proteins)**: PRKAR2A specifically associates with various AKAPs, which anchor PKA to specific subcellular sites. Noteworthy AKAPs include **AKAP6**, **AKAP13**, and **AKAP150**.
- **Other genes involved in cAMP signaling**, like **ADCY (Adenylyl cyclases)** and **PDE (Phosphodiesterases)**, may also directly or indirectly relate to PRKAR2A functionality by modulating cAMP levels.

### 2. Aging and Age-Related Diseases
Research has indicated that dysregulation of cAMP signaling, including the roles of regulatory proteins like PRKAR2A, can have implications for several age-related diseases such as:
- **Cardiovascular Diseases**: Changes in cAMP signaling are associated with aging-related cardiac hypertrophy and heart failure.
- **Neurodegenerative Diseases**: Impaired cAMP signaling due to altered PKA activity can contribute to diseases such as Alzheimer’s and Parkinson’s by affecting neuron signaling and survival.
- **Metabolic Disorders**: Age-associated insulin resistance and type 2 diabetes have been linked to alterations in cAMP pathways.
- **Cancer**: Abnormal PRKAR2A expression may have associations with certain tumors, specifically endocrine tumors as it plays a role in the regulation of cell proliferation.

### 3. Drug Interactions
While PRKAR2A itself may not be a direct drug target, it interacts with pathways influenced by various pharmaceutical agents:
- **Cyclic AMP phosphodiesterase inhibitors**: These drugs (e.g., caffeine, rolipram) increase cellular cAMP levels, indirectly affecting PKA activity.
- **Adrenergic Agonists**: Drugs that stimulate adenylate cyclase (e.g., beta-adrenergic agonists) will ultimately affect cAMP levels and thus impact PRKAR2A functions.
- **Anti-cancer agents**: Certain inhibitors targeting signaling pathways may also affect cAMP signaling indirectly, leading to modulation of the functions of proteins governed by PRKAR2A.

### 4. Pathways and Biological Processes
PRKAR2A is involved in various signaling pathways and biological processes, including:
- **cAMP signaling pathway**: Fundamental to the transmission of hormonal signals and modulation of various physiological responses.
- **Regulation of Gene Expression**: PKA signaling can influence transcription factors involved in gene expression.
- **Endocytic Recycling**: Regulates the transport of proteins from endosomes to the Golgi apparatus and ER, crucial for maintaining cellular homeostasis.
- **Cell Growth and Differentiation**: Through modulation of PKA activity, PRKAR2A participates in controlling aspects of cell proliferation and differentiation.
- **Cardiovascular function**: Influences cardiac muscle contractility and function through modulation of calcium channels and other relevant substrates in cardiac tissues.

In summary, PRKAR2A gene plays a multifaceted role in cellular signaling with implications in various diseases, interactions with other kinases, and potential relevance in pharmacological interventions. Its dysregulation might be linked to age-related dysfunctions, making it an essential target for further research in understanding these complexities.