### FFAR3 Gene Overview

**Gene Symbol:** FFAR3  
**Gene Type:** Protein-coding  
**Location:** Plasma membrane  
**Function:** G protein-coupled receptor (GPCR) activity  

#### Summary of Functions
The FFAR3 gene encodes a G protein-coupled receptor that is activated by short-chain fatty acids (SCFAs) produced primarily from the fermentation of dietary fibers by the gut microbiome. The key short-chain fatty acids that activate FFAR3 include acetate, propionate, and butyrate. Activation of this receptor is involved in several physiological processes, including:

- Regulation of energy homeostasis
- Modulation of intestinal immunity
- Signal transduction pathways involving inositol trisphosphate and calcium mobilization
- Control of hormonal secretion related to energy balance (e.g., PYY and potentially leptin)
- Regulation of gut motility and intestinal transit

### Additional Information

1. **Associated Genes:**
   - **GPR41 (FFAR2):** Another GPCR involved in SCFA signaling.
   - **LEP (Leptin):** Regulates energy balance and fat storage.
   - **PYY:** A hormone produced by enteroendocrine cells, involved in appetite suppression and gut physiology.

2. **Aging and Age-Related Diseases:**
   - The role of FFAR3 in energy metabolism suggests potential implications in obesity and metabolic syndrome, which are more prevalent in aging populations.
   - SCFAs and their signaling through FFAR3 may influence inflammation and immune responses, which could correlate with age-related inflammatory diseases (e.g., senescence-associated secretory phenotype).
   - Some studies have linked the microbiome and SCFAs in the context of neurodegenerative diseases, highlighting a potential role for FFAR3 in cognitive decline associated with aging.

3. **Drug Interactions:**
   - Currently, there are no well-established drugs that specifically target FFAR3, but understanding its role in SCFA signaling may lead to the development of therapeutics aimed at modulating metabolic and inflammatory pathways.
   - Class of compounds being researched: fiber-related dietary supplements and microbial metabolites (SCFAs), which could have indirect effects on FFAR3 activation.

4. **Pathways and Biological Processes:**
   - **Adenylate Cyclase-Inhibiting G Protein-Coupled Receptor Signaling Pathway:** FFAR3 is part of this signaling cascade which regulates various downstream effects in the cell, primarily inhibiting cAMP accumulation.
   - **Calcium Signaling:** Involvement in the mobilization of intracellular calcium levels upon activation.
   - **MAPK Signaling Pathway:** FFAR3 activation leads to the phosphorylation of MAPKs (MAPK1/ERK2 and MAPK3/ERK1), linking to various cellular responses such as growth, differentiation, and inflammation.
   - **Immune Response Regulation:** Potential mediator of SCFA-induced immune response, aiding in the regulation of chemokine and cytokine production.
   - **Metabolic Regulation:** Influences processes such as glucose homeostasis, energy expenditure, and hormonal (e.g., leptin and PYY) regulation.

### Summary
The FFAR3 gene is crucial for mediating the physiological effects of short-chain fatty acids on energy metabolism and immune responses. Its implications in aging and metabolic health make it a potential target for further research and therapeutic developments, especially concerning age-related diseases and obesity management.