Chromatin landscape: methylation beyond transcription.

The nucleus is organized and compartmentalized into a highly ordered structure that contains DNA, RNA, chromosomal and histone proteins. The dynamics associated with these various components are responsible for making sure that the DNA is properly duplicated, genes are properly transcribed, and the genome is stabilized. It is no surprise that alterations in these various components are directly associated with pathologies like cancer. This Point of View focuses on the role the chromatin modification landscape, especially histone 3 lysine 9 methylation (H3K9me), and heterochromatin proteins (HP1) play in regulating DNA-templated processes, with a particular focus on their role at non-genic regions and effects on chromatin structure. These observations will be further extended to the role that alterations in chromatin landscape will contribute to diseases. This Point of View emphasizes that alterations in histone modification landscapes are not only relevant to transcription but have broad range implications in chromatin structure, nuclear architecture, cell cycle, genome stability and disease progression.