Targeting of 5-aza-2′-deoxycytidine residues by chromatin-associated DNMT1 induces proteasomal degradation of the free enzyme
Open Access
- 25 March 2010
- journal article
- research article
- Published by Oxford University Press (OUP) in Nucleic Acids Research
- Vol. 38 (13), 4313-4324
- https://doi.org/10.1093/nar/gkq187
Abstract
5-Aza-2′-deoxycytidine (5-aza-dC) is a nucleoside analogue with cytotoxic and DNA demethylating effects. Here we show that 5-aza-dC induces the proteasomal degradation of free (non-chromatin bound) DNMT1 through a mechanism which is dependent on DNA synthesis and the targeting of incorporated 5-aza-dC residues by DNMT1 itself. Thus, 5-aza-dC induces Dnmt1 degradation in wild-type mouse ES cells, but not in Dnmt [3a –/– , 3b –/– ] mouse ES cells which express Dnmt1 but lack DNA methylation (<0.7% of CpG methylated) and contain few hemi-methylated CpG sites, these being the preferred substrates for Dnmt1. We suggest that adducts formed between DNMT1 and 5-aza-dC molecules in DNA induce a ubiquitin-E3 ligase activity which preferentially targets free DNMT1 molecules for degradation by the proteasome. The proteasome inhibitor MG132 prevents DNMT1 degradation and reduces hypomethylation induced by 5-aza-dC.Keywords
This publication has 22 references indexed in Scilit:
- MBD4 and MLH1 are required for apoptotic induction in xDNMT1-depleted embryosDevelopment, 2009
- RETRACTED: A New Class of Quinoline-Based DNA Hypomethylating Agents Reactivates Tumor Suppressor Genes by Blocking DNA Methyltransferase 1 Activity and Inducing Its DegradationCancer Research, 2009
- A versatile non-radioactive assay for DNA methyltransferase activity and DNA bindingNucleic Acids Research, 2009
- DNA Methylation Inhibitor 5-Aza-2′-Deoxycytidine Induces Reversible Genome-Wide DNA Damage That Is Distinctly Influenced by DNA Methyltransferases 1 and 3BMolecular and Cellular Biology, 2008
- Complete inactivation of DNMT1 leads to mitotic catastrophe in human cancer cellsNature Genetics, 2007
- Identification of DNMT1 (DNA methyltransferase 1) hypomorphs in somatic knockouts suggests an essential role for DNMT1 in cell survivalProceedings of the National Academy of Sciences of the United States of America, 2006
- 5-Aza-Deoxycytidine Induces Selective Degradation of DNA Methyltransferase 1 by a Proteasomal Pathway That Requires the KEN Box, Bromo-Adjacent Homology Domain, and Nuclear Localization SignalMolecular and Cellular Biology, 2005
- Severe Global DNA Hypomethylation Blocks Differentiation and Induces Histone Hyperacetylation in Embryonic Stem CellsMolecular and Cellular Biology, 2004
- Human DNA-(Cytosine-5) Methyltransferase-PCNA Complex as a Target for p21 WAF1Science, 1997
- Mechanism of action of eukaryotic DNA methyltransferase: Use of 5-azacytosine-containing DNAJournal of Molecular Biology, 1982