Stankevičius V, Gibas P, Masiulionytė B, Gasiulė L, Masevičius V, Klimašauskas S, Vilkaitis G. Selective chemical tracking of Dnmt1 catalytic activity in live cells.
Mol Cell 2022;
82:1053-1065.e8. [PMID:
35245449 PMCID:
PMC8901439 DOI:
10.1016/j.molcel.2022.02.008]
[Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/04/2021] [Accepted: 02/01/2022] [Indexed: 12/24/2022]
Abstract
Enzymatic methylation of cytosine to 5-methylcytosine in DNA is a fundamental epigenetic mechanism involved in mammalian development and disease. DNA methylation is brought about by collective action of three AdoMet-dependent DNA methyltransferases, whose catalytic interactions and temporal interplay are poorly understood. We used structure-guided engineering of the Dnmt1 methyltransferase to enable catalytic transfer of azide tags onto DNA from a synthetic cofactor analog, Ado-6-azide, in vitro. We then CRISPR-edited the Dnmt1 locus in mouse embryonic stem cells to install the engineered codon, which, following pulse internalization of the Ado-6-azide cofactor by electroporation, permitted selective azide tagging of Dnmt1-specific genomic targets in cellulo. The deposited covalent tags were exploited as “click” handles for reading adjoining sequences and precise genomic mapping of the methylation sites. The proposed approach, Dnmt-TOP-seq, enables high-resolution temporal tracking of the Dnmt1 catalysis in mammalian cells, paving the way to selective studies of other methylation pathways in eukaryotic systems.
A single alanine substitution in Dnmt1 confers catalytic transfer of extended groups
Electroporation permits facile delivery of AdoMet analogs into live mammalian cells
Engineered Dnmt1 adds trackable azide tags at its native target sites in cellulo
Dnmt-TOP-seq enables genome-wide tracking of Dnmt1 activity in live mammalian cells
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