### RHEB Gene Overview

- **Gene Symbol**: RHEB
- **Gene Type**: Protein Coding
- **Location**: Chromosome 7 (7q34)
- **Protein Information**: The encoded protein is a small GTPase belonging to the RAS superfamily and is involved in numerous signaling pathways, particularly in the regulation of cellular growth and metabolism through its role in the mTORC1 (mechanistic target of rapamycin complex 1) signaling pathway.

### 1. Associated Genes
In addition to genes directly referenced in the summaries provided, RHEB is associated with other genes, including but not limited to:
- **mTOR (mechanistic target of rapamycin)**: RHEB activates mTORC1 by facilitating the interaction of mTOR with its substrates.
- **S6K1 (Ribosomal protein S6 kinase beta-1)**: Involved in cell growth-related signaling pathways, activated by mTORC1.
- **4EBP1 (Eukaryotic translation initiation factor 4E-binding protein 1)**: Also a substrate of mTOR, regulating translation initiation.
- **TSC1/TSC2 (Tuberous sclerosis complex proteins)**: RHEB functions downstream of the TSC complex which acts as a negative regulator of mTORC1 signaling.

### 2. Aging and Age-Related Diseases
RHEB has been implicated in several aspects of aging and age-related diseases:
- **Cellular Senescence**: Altered RHEB activity is associated with the reduction of mTORC1 signaling in cellular senescence, where diminished growth signaling can maintain cellular longevity.
- **Age-related Pathologies**: RHEB’s role in mTORC1 signaling has been linked to various age-related diseases, including cancer, neurodegeneration, and metabolic disorders. Dysregulation of mTOR signaling pathways, which RHEB actively regulates, is a well-known factor in aging and lifespan determination.
- **Caloric Restriction**: Studies suggest that reductions in the mTOR pathway can mimic the effects of caloric restriction, a known lifespan-extending intervention.

### 3. Known Drug Interactions
RHEB interacts with molecular pathways targeted by various drugs:
- **mTOR Inhibitors**: 
  - **Rapamycin (Sirolimus)**: A specific inhibitor of mTORC1 that alters growth signaling involved in aging and cancer.
  - **Everolimus**: Another mTOR inhibitor used in cancer therapy and transplant rejection.
- **Metformin**: Though not a direct interaction with RHEB, metformin has been shown to affect mTOR signaling, suggesting an indirect interaction due to RHEB’s involvement in this pathway.

### 4. Pathways and Biological Processes
RHEB is involved in several key biological processes and signaling pathways:
- **mTORC1 Signaling Pathway**: Central to cell growth and metabolism.
- **Insulin Signaling Pathway**: Integrates signals related to nutrient availability influencing growth and metabolism.
- **Cell Cycle Regulation**: Through modulation of mTOR signaling, RHEB influences cell cycle progression.
- **Cellular Apoptosis**: RHEB's activation of mTORC1 contributes to cell survival signals, thereby impacting apoptosis.

Overall, RHEB plays a critical role in growth factor signaling pathways and is integral to multiple biological processes including metabolism, cellular growth, and apoptosis, with significant implications for aging and age-associated diseases.