Usp7 and Uhrf1 control ubiquitination and stability of the maintenance DNA methyltransferase Dnmt1

Journal of Cellular Biochemistry, 2011, DOI: 10.1002/jcb.22998, published on 25.01.2011
Journal of Cellular Biochemistry, online article
In mammals Dnmt1 is the DNA methyltransferase chiefly responsible for maintaining genomic methylation patterns through DNA replication cycles, but how its maintenance activity is controlled is still not well understood. Interestingly, Uhrf1, a crucial cofactor for maintenance of DNA methylation by Dnmt1, is endowed with E3 ubiquitin ligase activity. Here, we show that both Dnmt1 and Uhrf1 coprecipitate with ubiquitin specific peptidase 7 (Usp7), a de-ubiquitinating enzyme. Overexpression of Uhrf1 and Usp7 resulted in opposite changes in the ubiquitination status and stability of Dnmt1. Our findings suggest that, by balancing Dnmt1 ubiquitination, Usp7 and Uhrf1 fine tune Dnmt1 stability.

TU München
Helmholtz München
MPI of Neurobiology
MPI of Biochemistry