### SULT1A3 Gene Overview

**Gene Symbol:** SULT1A3  
**Location:** Chromosome 16 (p arm)  
**Type:** Sulfotransferase enzyme  

### Summary of Function
The SULT1A3 gene encodes a phenol sulfotransferase that is responsible for catalyzing the sulfate conjugation of various substrates, including phenolic monoamines (such as neurotransmitters like dopamine, norepinephrine, and serotonin) and phenolic drugs. This enzyme utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) as the sulfonate donor. Its activity is characterized as thermolabile, indicating that it may lose activity at elevated temperatures.

### 1. Associated Genes
The SULT1A3 gene is associated with several other genes located within the same genomic region on chromosome 16, particularly:
- **SULT1A1**: Another member of the sulfotransferase family with similar enzymatic function.
- **SULT1A4**: A closely related sulfotransferase that arose from segmental duplication, sharing structural and functional similarities.
- **SLX1A**: The upstream gene that can undergo read-through transcription, encoding a protein with GIY-YIG domains.

### 2. Aging and Age-Related Diseases
Current research suggests a potential involvement of SULT1A3 in age-related processes, but specific mechanisms or direct associations with age-related diseases require further exploration. Sulfation pathways are crucial in the metabolism of various hormones and neurotransmitters, which may be impacted in aging, affecting cognitive functions and hormonal regulation. Investigating how sulfotransferase activities change with age could unveil critical insights for age-related diseases, but definitive associations with specific conditions remain to be elucidated.

### 3. Drug Interactions
The SULT1A3 enzyme has been identified to interact with various drugs and substances, specifically:
- **Catecholamines**: Such as epinephrine and norepinephrine, where sulfation may influence their bioavailability and metabolism.
- **Certain Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)**: Drugs like acetaminophen (paracetamol) can undergo sulfation, and the enzymatic activity of SULT1A3 may modulate their pharmacokinetics.
- **Antidepressants**: Some selective serotonin reuptake inhibitors (SSRIs), such as sertraline, may also be substrates for this enzyme, influencing their efficacy and metabolism.

### 4. Pathways and Biological Processes
SULT1A3 is involved in several biological pathways, including:

- **Drug Metabolism**: Contributing to the phase II metabolism where drugs and xenobiotics are converted into more water-soluble forms for excretion.
- **Hormone Regulation**: Participating in the metabolic processes of steroid hormones and thyroid hormones via sulfation.
- **Neurotransmitter Regulation**: Sulfation of neurotransmitters like dopamine and serotonin has implications for mental health disorders.

### Conclusion
The SULT1A3 gene plays a pivotal role in the sulfation of various biological molecules, impacting drug metabolism and neurotransmitter regulation. Further research into its interactions and implications for aging and pharmacogenetics will enhance our understanding of this vital gene.