Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Postreplicative maintenance of genomic methylation patterns was proposed to depend largely on the binding of DNA methyltransferase 1 (Dnmt1) to PCNA, a core component of the replication machinery. We investigated how the slow and discontinuous DNA methylation could be mechanistically linked with fast and processive DNA replication. Using photobleaching and quantitative live cell imaging we show that Dnmt1 binding to PCNA is highly dynamic. Activity measurements of a PCNA-binding-deficient mutant with an enzyme-trapping assay in living cells showed that this interaction accounts for a 2-fold increase in methylation efficiency. Expression of this mutant in mouse dnmt1-/- embryonic stem (ES) cells restored CpG island methylation. Thus association of Dnmt1 with the replication machinery enhances methylation efficiency, but is not strictly required for maintaining global methylation. The transient nature of this interaction accommodates the different kinetics of DNA replication and methylation while contributing to faithful propagation of epigenetic information.

Original publication

DOI

10.1093/nar/gkm432

Type

Journal article

Journal

Nucleic Acids Res

Publication Date

2007

Volume

35

Pages

4301 - 4312

Keywords

Amino Acid Sequence, Animals, Binding Sites, Cell Line, CpG Islands, DNA (Cytosine-5-)-Methyltransferase 1, DNA (Cytosine-5-)-Methyltransferases, DNA Methylation, DNA Replication, Embryonic Stem Cells, Fluorescence Recovery After Photobleaching, Humans, Mice, Mice, Knockout, Molecular Sequence Data, Point Mutation, Proliferating Cell Nuclear Antigen, Protein Structure, Tertiary, Sequence Alignment