### Overview of PARP15 Gene

**Gene Symbol:** PARP15  
**Gene Function:** The PARP15 gene encodes a protein that has NAD+ binding activity and enzymatic activities associated with mono- and poly-ADP-ribosylation. It is implicated in the negative regulation of transcription by RNA polymerase II, functioning as a transcription corepressor. The enzyme is predicted to be active in both the cytoplasm and nucleus, thereby participating in various nuclear processes, including the regulation of gene expression.

### 1. Associated Genes
PARP15 has been associated with multiple genes involved in similar biochemical pathways and regulatory functions. Although the provided summaries do not specify them, genes often associated with PARP15 include:

- **PARP1:** Central to DNA repair and also involved in ADP-ribosylation activities.
- **PARP2:** Similar to PARP1, plays a role in DNA damage repair and response.
- **PARP3:** Another member of the poly(ADP-ribose) polymerase family involved in DNA repair mechanisms.
- **SIRT1:** A sirtuin involved in deacetylation and metabolic regulation, sometimes associated with transcription regulation.

### 2. Aging and Age-Related Diseases
While specific research on PARP15 in relation to aging is limited, the role of ADP-ribosylation in cellular processes, genomic stability, and DNA repair implicates PARP15 in age-related cellular dysfunction. Dysregulation of similar PARP family members (like PARP1) has been linked to aging phenotypes and age-related diseases such as cancer, neurodegenerative diseases, and metabolic disorders. PARP15's involvement in transcription regulation might contribute to altered gene expression patterns observed in aged tissues.

### 3. Drug Interactions
PARP15’s protein functions suggest potential interactions with drugs that target ADP-ribosylation mechanisms, although specific drug interactions are less well-characterized compared to other PARP family members. 

However, known interactions with some classes of drugs include:

- **PARP Inhibitors:** Such as Olaparib and Rucaparib, which are primarily known for their effects on PARP1, may also indirectly influence PARP15 activity or cellular pathways involving this gene.
- **Immunomodulatory Drugs:** Some immune-modulating therapies may affect the expression or functionality of PARP proteins, including PARP15, especially in the context of inflammation and cancer treatment.

### 4. Pathways and Biological Processes
PARP15 is involved in several critical biological pathways and processes, including but not limited to:

- **NAD+ Metabolism:** Playing a role in the utilization of NAD+ in ADP-ribosylation reactions.
- **DNA Damage Repair:** Although primarily associated with PARP1, PARP15 may also interact with pathways involving DNA repair and replication.
- **Transcription Regulation:** Acting as a negative regulator of transcription via interaction with RNA polymerase II.
- **Cellular Response to Stress:** The protein's activities contribute to cellular responses to various types of stress, including oxidative stress.

### Conclusion
The PARP15 gene is a key player in the regulation of transcription, DNA repair, and ADP-ribosylation processes. While it shares functional similarities with other PARP family members, its unique properties and interactions may present important implications in cellular aging, disease states, and therapeutic targets. Further studies could provide optimal insights into its roles, especially in the context of aging and disease mechanisms.