### METTL22 Gene Overview

#### Gene Summary:
- **Gene Symbol**: METTL22
- **Function**: METTL22 is a non-histone lysine methyltransferase that influences various cellular processes by methylating lysine residues on target proteins. It specifically interacts with Kin17, which plays a role in DNA repair, replication, and mRNA processing.
- **Protein Product**: It acts as a protein N-lysine methyltransferase, with the ability to trimethylate Lys-135 on Kin17 in vitro.
- **Alternative Splicing**: The METTL22 gene produces multiple transcript variants through alternative splicing, contributing to functional diversity.

### 1. Associated Genes:
While specific associations can be deduced based on the functions of the genes involved, the following genes are known to have potential interactions or relevance in pathways that METTL22 is involved with:
- **Kin17 (KIN)**: Direct substrate for METTL22 and involved in DNA repair and mRNA processing.
- **DNMTs (DNA Methyltransferases)**: Epigenetic modifiers that similarly influence gene expression and may interact in regulatory networks with METTL22.
- **Other RNA-binding proteins**: Given its involvement in mRNA processing, METTL22 may interact indirectly with other RNA-binding proteins.

### 2. Aging and Age-Related Diseases:
- **Potential Associations**: There is limited direct information regarding METTL22's role in aging or age-related diseases in the literature as of October 2023. However, given its involvement in DNA repair and mRNA processing, disturbances in METTL22 potentially contribute to the accumulation of cellular damage over time, which is a hallmark of aging.
- **Neurodegenerative Diseases**: Given that dysregulation in RNA-processing proteins has been associated with neurodegenerative diseases, METTL22 might be implicated indirectly in such conditions due to its function.

### 3. Drug Interactions:
While there may be no specific drugs targeting METTL22 directly identified in the literature, methyltransferase inhibitors might interact with its function. Classes of compounds that may affect functions of non-histone methyltransferases include:
- **S-Adenosyl Homocysteine (SAH) analogs**: Competitive inhibitors of methyltransferases.
- **Small-molecule inhibitors of methyltransferases**: These could broadly inhibit the class of proteins that METTL22 belongs to but may not be specific to METTL22 alone.

### 4. Pathways and Biological Processes:
METTL22 is implicated in several biological processes and pathways, including:
- **DNA Repair**: Through its interaction with Kin17.
- **Replication Fork Stability**: It plays a role in stabilizing DNA replication forks which is crucial for genome integrity.
- **mRNA Processing**: As METTL22 is involved in mRNA processing, it participates in pathways regulating gene expression.
- **Epigenetic Regulation**: It contributes to the broader field of epigenetics by methylating lysines on various proteins, potentially altering their functions and interactions.

In summary, METTL22 is a key player in various biological processes, particularly those involving DNA repair, replication, and mRNA processing. While direct implications in aging and age-related diseases are still being investigated, its functional roles in cell maintenance and gene expression might indicate a more significant impact on cellular aging and the prevention of age-related dysfunction.