Metülatsioon

Metülatsioon is a biochemical process in which a methyl group (CH3) is added to a molecule, typically a DNA molecule or a protein. This process is catalyzed by enzymes known as methyltransferases. Metülatsioon plays a crucial role in various biological functions, including gene regulation, DNA repair, and protein modification.

In the context of DNA, metülatsioon occurs primarily on cytosine bases, forming 5-methylcytosine (5mC). This modification can occur in both CpG dinucleotides (where cytosine is followed by guanine) and non-CpG contexts. DNA metülatsioon is dynamic, meaning it can be added and removed by specific enzymes. It is involved in gene silencing, X chromosome inactivation, and genomic imprinting.

Protein metülatsioon, on the other hand, can occur on various amino acid residues, such as lysine, arginine, and histidine. This modification can influence protein stability, localization, and activity. For example, histone metülatsioon is a key regulator of chromatin structure and gene expression.

Metülatsioon is tightly regulated and deregulation can lead to various diseases, including cancer. For instance, global hypo- or hypermetülation of DNA is associated with cancer development. Similarly, altered protein metülation has been linked to neurodegenerative diseases and metabolic disorders.

Metülatsioon is a fundamental epigenetic modification that contributes to the regulation of gene expression and protein function. Understanding the mechanisms and functions of metülatsioon is essential for advancing our knowledge of biological processes and developing therapeutic strategies for related diseases.