### MUS81 Gene Overview

**Gene Symbol:** MUS81

**Function:** The MUS81 gene encodes a structure-specific endonuclease that plays a critical role in DNA repair, particularly in resolving recombination intermediates following inter-strand cross-links, replication fork collapse, and DNA double-strand breaks. The protein formed from this gene is a part of the XPF/MUS81 endonuclease family.

### Additional Genes Associated with MUS81
While the NCBI and UniProt summaries mention **EME1** and **EME2** as direct interaction partners that form a complex with MUS81, there are other genes and gene families often studied in relation to MUS81:

1. **XRCC3** - Critical for homologous recombination repair.
2. **RAD51** - Necessary for DNA strand exchange during recombination.
3. **BRCA1/BRCA2** - Mutations in these genes are associated with breast cancer and their products interact with repair pathways involving MUS81.
4. **FANCM** - Associated with the Fanconi anemia pathway which is involved in repairing interstrand crosslinks.

### Aging and Age-Related Diseases
While research directly linking MUS81 to aging or specific age-related diseases is limited, several considerations are noteworthy:

- **DNA Repair Capacity**: Defective DNA repair is associated with aging and the onset of age-related diseases. As MUS81 is essential for the repair of DNA, its dysfunction could contribute to genomic instability, a hallmark of aging.
- **Cancer Susceptibility**: Given its role in DNA repair, any mutations or dysregulation of MUS81 may increase the risk of cancers, which are more prevalent with increasing age.

### Known Drug Interactions
Currently, there are no specific drugs or drug classes that are widely documented to directly target MUS81. However, drugs targeting DNA repair pathways in general (e.g., PARP inhibitors) might indirectly influence its function, especially considering its role in homologous recombination repair.

### Pathways and Biological Processes
MUS81 is involved in several critical pathways and biological processes, including:

1. **DNA Repair**: Functions prominently in the processing of DNA structures during repair.
2. **Meiotic Recombination**: Plays a role in meiotic processes, particularly during the formation and resolution of Holliday junctions.
3. **Cell Cycle Regulation**: Crucial for the maintenance of genomic stability during cell division.
4. **Response to DNA Damage**: Contributes to the cellular response to various forms of DNA damage, including double-strand breaks and stalled replication forks.

### Summary
The MUS81 gene is integral to DNA repair mechanisms, especially in the context of meiotic recombination and replication fork processing. While there is a need for further studies to establish strong links to aging and therapeutic targets, its association with other DNA repair genes underlines its importance in genomic stability and cancer susceptibility.