DNA methylation landscapes in human cells and their chromatin determinants

Since H3K36me2 and H3K36me3 are recognized by the reader domains of the DNA methyltransferases DNMT3A and DNMT3B, and H3K36 methylation is a block to the PRC2 methyltransferases, these two types of crosstalk may explain the stable maintenance and antagonism between H3K27me3 and broad DNA methylation domains. However, methylated CpG islands are depleted of H3K36me2 and show a different relationship between DNA methylation and H3K36me2 deposition compared to non-CpG island regions. The data give insight into how DNA methylation patterns are established in human cells. We discuss these findings and their potential relevance for altered DNA methylation patterns seen in aging tissues and in cancer cells.