Format

Send to:

Choose Destination
See comment in PubMed Commons below
Nucleic Acids Res. 2007;35(13):4301-12. Epub 2007 Jun 18.

Dynamics of Dnmt1 interaction with the replication machinery and its role in postreplicative maintenance of DNA methylation.

Author information

  • 1Ludwig Maximilians University Munich, Department of Biology II, 82152 Martinsried, Germany.

Abstract

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.

PMID:
17576694
[PubMed - indexed for MEDLINE]
PMCID:
PMC1934996
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk