### Overview of FBXL18 Gene

**Gene Symbol:** FBXL18

**Function:** The FBXL18 gene encodes a member of the F-box protein family, characterized by a conserved F-box motif of approximately 40 amino acids. F-box proteins play critical roles in the ubiquitin-proteasome system, primarily acting as substrate-recognition components of the SCF (SKP1-CUL1-F-box protein) E3 ubiquitin ligase complex. FBXL18 specifically targets proteins like FBXL7 for polyubiquitylation and subsequent proteasomal degradation, thereby regulating cellular processes such as the cell cycle and cellular response to stress.

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### 1. Associated Genes

While the provided summaries focus on FBXL18's interaction with FBXL7, additional genes and proteins that may be indirectly associated with FBXL18 include:

- **FBXL7:** Direct substrate of FBXL18 and involved in mitotic arrest.
- **SKP1:** A key interaction partner as part of the SCF ubiquitin ligase complex.
- **CUL1:** Another component of the SCF complex.
- **UBQLN2:** Ubiquilin 2, a protein involved in the regulation of proteasomal degradation, might have functional overlaps with FBXL18.
- **Various Cyclins and CDKs:** Involved in cell cycle regulation.

### 2. Aging and Age-Related Diseases

The role of FBXL18 in the regulation of cell cycle proteins can be linked to cellular aging and age-related diseases. Some known aspects include:

- **Cell Cycle Regulation:** As FBXL18 can influence proteins that modulate the cell cycle, dysregulation may contribute to senescence, a hallmark of aging, and age-related cancers.
- **Protein Homeostasis:** Impaired protein degradation pathways are known contributors to age-related pathologies, including neurodegenerative diseases. The potential regulation of proteins that are involved in these pathways by FBXL18 could have implications in these conditions.

### 3. Drug Interactions

Currently, specific drugs or drug classes directly interacting with FBXL18 are not well-established. However, drugs that target the ubiquitin-proteasome pathway broadly—such as proteasome inhibitors (e.g., Bortezomib)—might indirectly influence FBXL18 function through their effects on protein degradation mechanisms.

### 4. Pathways and Biological Processes

FBXL18 is involved in several critical biological processes, including:

- **Ubiquitin-Protein Ligase Activity:** As part of the SCF complex, it helps attach ubiquitin moieties to target proteins for degradation.
- **Cell Cycle Regulation:** By targeting mitotic regulators like FBXL7, it plays a significant role in managing the progression of the cell cycle.
- **Protein Ubiquitination:** General role in tagging proteins for degradation, important for maintaining protein homeostasis.
- **Response to Stress:** Associated with the cellular response to various stressors via modulation of critical regulatory proteins.

FBXL18's roles significantly influence both normal cellular function and disease processes, highlighting its importance in cellular regulation and potential relevance in therapeutic contexts.