Methyllysine

Methyllysine is a post-translational modification of lysine, one of the 20 standard amino acids found in proteins. This modification involves the addition of a methyl group to the ε-amino group of a lysine residue. Methylation of lysine residues is a common and reversible process that plays a crucial role in various biological functions, including gene regulation, protein-protein interactions, and cellular signaling.

There are three main types of methyllysine modifications: mono-, di-, and trimethylation. Each type can occur on different lysine residues within a protein, leading to a diverse array of methyllysine modifications. These modifications are catalyzed by specific enzymes known as protein lysine methyltransferases (KMTs) and demethylases, which add or remove methyl groups, respectively.

Methyllysine modifications are often found in histone proteins, which are the structural proteins around which DNA is packaged in chromatin. These modifications can influence chromatin structure and gene expression by altering the accessibility of DNA to transcription machinery. Additionally, methyllysine modifications can regulate the activity and stability of non-histone proteins, affecting various cellular processes such as cell cycle progression, apoptosis, and signal transduction.

The study of methyllysine modifications has gained significant attention in recent years due to their potential as therapeutic targets in diseases such as cancer, neurodegenerative disorders, and metabolic diseases. Understanding the mechanisms and functions of methyllysine modifications is essential for developing new strategies to modulate these processes and treat related diseases.