Methyltransferases catalyze the addition of methyl groups onto various types of substrates, including nucleic acids, small molecules and proteins. In proteins, this type of post translational modification (PTM) is involved in regulating protein-protein interactions, protein-DNA interactions, and protein activation. Methylation plays an important role epigenetic regulation, through which the modification of histones and DNA activate or silence the transcription of genes.
DNA methylation is important for genomic imprinting, X-chromosome inactivation, and suppression of repetitive DNA elements. Methylated DNA acts in two ways to silence transcription; by directly preventing transcription factors binding; and by recruiting additional transcriptional regulatory proteins to the modified region. On histones, lysine residues can be mono-, di- or tri-methylated, whereas arginines can only be mono- and di-methylated. Histone methylation alters the level chromatin condensation by affecting the net charge of the protein.
In cell signaling, methylation is required for activating protein phosphatases such as PP2A. PP2A is a tumor suppressor that targets many oncogenic serine/threonine kinases (STKs). PP2A methylation and demethylation is carried out by LCMT1 and PPME1 respectively.
SignalChem offers a wide range of methyltransferases to facilitate studies on this diverse group of enzymes.