### FBXL3 Gene Overview

**Gene Symbol:** FBXL3  
**Location:** Chromosome 4 (4q13.3)  
**Function:** Encodes a protein that is a part of the SCF (SKP1-Cullin-F-box) complex, involved in ubiquitination and degradation of proteins, specifically the circadian rhythm-regulating proteins CRY1 and CRY2.

### 1. Associated Genes
FBXL3 is known to interact with several other genes, particularly those involved in circadian rhythms and the ubiquitin-proteasome system. Some notable genes include:

- **CRY1 and CRY2:** Regulate circadian rhythms and are targeted for degradation by the FBXL3-mediated ubiquitination process.
- **PER1, PER2, and PER3:** Circadian clock genes involved in feedback regulation of the clock machinery.
- **FBXL21:** Acts in opposition to FBXL3, promoting stability of the CRYs, highlighting the antagonistic relationship affecting circadian clock regulation.

### 2. Aging and Age-Related Diseases
Research suggests that circadian rhythms can influence aging and age-related diseases:

- **Circadian Rhythm and Aging:** Disruption in circadian rhythms may contribute to age-related decline in health. FBXL3's role in regulating CRYs implicates it in maintaining circadian stability, which affects overall biological rhythms as one ages.
- **Cancer:** Altered expression of circadian genes, including FBXL3, has been studied for its links to tumorigenesis. Dysregulation in the ubiquitin-proteasome system may lead to the accumulation of oncoproteins in various cancers.
- **Neurodegenerative Disorders:** Emerging evidence points to circadian dysfunction in disorders like Alzheimer’s and Parkinson’s disease, with variations in FBXL3 expression correlating to risk factors.

### 3. Drug Interactions
While specific drug interactions directly targeting FBXL3 are not extensively documented, the following considerations are relevant:

- **Circadian Modulators:** Drugs influencing circadian rhythms, like melatonin, could indirectly affect FBXL3 function due to its role in circadian regulation.
- **Proteasome Inhibitors:** Compounds that inhibit the ubiquitin-proteasome system may alter FBXL3 activity and function, as FBXL3's role involves the ubiquitin-mediated degradation of proteins.

### 4. Pathways and Biological Processes
FBXL3 is involved in several critical biological processes:

- **Ubiquitin-Proteasome Pathway:** It plays a crucial role in the ubiquitination and degradation of target proteins, vital for protein homeostasis and signaling.
- **Circadian Rhythm Regulation:** FBXL3 is essential for maintaining normal circadian clock oscillations, influencing processes like sleep-wake cycles, hormone release, and metabolic functions.
- **Negative Regulation of Gene Expression:** Through the degradation of CRYs, FBXL3 modulates the feedback loops critical for circadian rhythm stability.

These details collectively underscore the significance of FBXL3 in both fundamental biological mechanisms and its potential implications in aging and disease. Its involvement in circadian rhythms offers intriguing avenues for further research, especially in understanding age-related physiological changes.