Tracking DOT1L methyltransferase activity by stable isotope labelling using a selective synthetic co-factor

• Published in: Communications chemistry Vol. 7; no. 1; pp. 145 - 7
• Main Authors: Trainor, Nicole, Whitwell, Harry J., Jiménez, Beatriz, Addison, Katie, Leonidou, Emily, DiMaggio, Peter A., Fuchter, Matthew J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 27.06.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/92/475; 631/92/96; 639/638/11/296; 639/638/92; 82/58; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Deoxyribonucleic acid; DNA; Epigenetics; Gene expression; Gene sequencing; Histones; Labels; Lysine; Mass spectrometry; Methionine; Methylation; Proteins; Proteomics; Redundancy; Substrates; Tracking
• ISSN: 2399-3669; 2399-3669
• DOI: 10.1038/s42004-024-01227-x

Epigenetic processes influence health and disease through mechanisms which alter gene expression. In contrast to genetic changes which affect DNA sequences, epigenetic marks include DNA base modifications or post-translational modification (PTM) of proteins. Histone methylation is a prominent and versatile example of an epigenetic marker: gene expression or silencing is dependent on the location and extent of the methylation. Protein methyltransferases exhibit functional redundancy and broad preferences for multiple histone residues, which presents a challenge for the study of their individual activities. We developed an isotopically labelled analogue of co-factor S-adenosyl-L-methionine ( 13 CD 3 -BrSAM), with selectivity for the histone lysine methyltransferase DOT1L, permitting tracking of methylation activity by mass spectrometry (MS). This concept could be applied to other methyltransferases, linking PTM discovery to enzymatic mediators. Histone methylation by histone lysine methyltransferases (HKMTs) is a vital post-translational modification regulating gene expression, however, selective mapping of methylation by proteomics analysis remains challenging. Here, the authors develop a heavy co-factor analogue 13 CD 3 -BrSAM for HKMT DOT1L that can selectively heavy label target substrates, and map their methylation by proteomics.