### HECTD3 Gene Overview

**Gene Symbol:** HECTD3  
**Location:** Human chromosome 10 (10p11.22)  
**Function:** HECTD3 encodes a protein that functions as an E3 ubiquitin ligase, transferring ubiquitin from E2 conjugating enzymes to specific substrate proteins, facilitating their degradation via the proteasome. It is specifically involved in the ubiquitination and degradation of proteins such as TRIOBP and STX8, playing a crucial role in regulating the cell cycle.

### 1. Associated Genes
The primary focus of HECTD3 is its interactions with specific substrates like **TRIOBP** (Trio Rho Guanine Nucleotide Exchange Factor Binding Protein) and **STX8** (Syntaxin 8). However, HECTD3 may interact with or be associated with other genes involved in ubiquitination, cell cycle regulation, and broader signaling pathways. Some potentially associated genes could include:

- **MDM2:** A negative regulator of the p53 tumor suppressor, known for its role in cell cycle regulation.
- **CCND1:** Cyclin D1, which plays a role in cell cycle progression and is regulated by ubiquitination.
- **p21 (CDKN1A):** A cyclin-dependent kinase inhibitor that can be regulated by E3 ubiquitin ligases.

### 2. Aging and Age-Related Diseases
While there is limited direct information on HECTD3 and its specific implications in aging or age-related diseases, the process of ubiquitination is essential for protein homeostasis, which declines with age. Dysregulation of ubiquitin-proteasome pathways has been implicated in several age-related diseases, including:

- **Neurodegenerative Diseases:** Such as Alzheimer's and Parkinson's, where protein aggregation can occur due to impaired proteasomal degradation.
- **Cancer:** As HECTD3 regulates the degradation of cell cycle proteins, its dysfunction may contribute to tumor progression or chemoresistance.

Further research may uncover more specific links between HECTD3 and the aging process or particular age-related conditions.

### 3. Drug Interactions
Currently, there is limited information on specific drugs or drug classes that directly interact with HECTD3. Since it plays a role in cellular processes like the cell cycle and apoptosis, drugs targeting these pathways (such as cyclin-dependent kinase inhibitors or proteasome inhibitors) may indirectly impact the functions of HECTD3. However, no specific drugs or drug classes are widely recognized to interact uniquely with this gene.

### 4. Pathways and Biological Processes
HECTD3 is involved in several crucial biological processes and pathways, including:

- **Ubiquitin-Proteasome Pathway:** It plays a pivotal role in protein degradation through ubiquitination, affecting various substrates implicated in different signaling cascades.
- **Cell Cycle Regulation:** By mediating the proteasomal degradation of cyclins and cell cycle regulators (e.g., TRIOBP), HECTD3 contributes to the orderly progression through the cell cycle.
- **Signal Transduction Pathways:** Functionally linked to Rho and Rac signaling pathways given its interaction with TRIOBP, impacting cellular processes like growth and migration.
- **Protein Metabolism:** Involvement in the turnover of proteins linked to metabolic activities.

### Conclusion
HECTD3 is an E3 ubiquitin ligase critical for various cellular processes, particularly in cell cycle regulation. Its role in ubiquitination highlights its potential implications in aging and age-related diseases, although this area requires further investigation. Understanding its interactions and associated genes offers insights into its broader biological functions.