Project description:Identification of the all RNA species associated with DNMT1. Using a comparative genome-scale approach we identified and correlated the RNA species physically associated with DNMT1 and proximal to the annotated genes to the methylation status of the corresponding loci and expression levels of the respective genes. This comparative approach delineated the first -DNMT1 centered- 'epitranscriptome' map, a comprehensive map cross-referencing DNMT1-interacting transcripts to (i) DNA methylation and (ii) gene expression profile. Relationship between DNMT1-RNA interactions, DNA methylation and gene expression
Project description:Identification of the all RNA species associated with DNMT1. Using a comparative genome-scale approach we identified and correlated the RNA species physically associated with DNMT1 and proximal to the annotated genes to the methylation status of the corresponding loci and expression levels of the respective genes. This comparative approach delineated the first -DNMT1 centered- 'epitranscriptome' map, a comprehensive map cross-referencing DNMT1-interacting transcripts to (i) DNA methylation and (ii) gene expression profile.
Project description:The DNA methyltransferase activity of DNMT1 is vital for genomic maintenance of DNA methylation. We report here that DNMT1 function is regulated by O-GlcNAcylation, a protein modification that is sensitive to glucose levels, and that elevated O-GlcNAcylation of DNMT1 from high glucose environment leads to alterations to the epigenome. Using mass spectrometry and complementary alanine mutation experiments, we identified S878 as the major residue that is O-GlcNAcylated on DNMT1. Functional studies further revealed that O-GlcNAcylation of DNMT1-S878 results in an inhibition of methyltransferase activity, resulting in a general loss of DNA methylation that is preferentially at partially methylated domains (PMDs). This loss of methylation corresponds with an increase in DNA damage and apoptosis. These results establish O-GlcNAcylation of DNMT1 as a mechanism through which the epigenome is regulated by glucose metabolism and implicates a role for glycosylation of DNMT1 in metabolic diseases characterized by hyperglycemia.