Into the chromatin world: Role of nuclear architecture in epigenome regulation

Epigenome modifications are established early in development and differentiation and generate distinct levels of chromatin complexity. The specific position of chromosomes and the compaction state of chromatin are both typical features that make it possible to distinguish between repressive and permissive environment for gene expression. In this review we describe the distinct levels of epigenome structures, emphasizing the role of nuclear architecture in the control of gene expression. Recent novel insights have increasingly demonstrated that the nuclear environment can influence nuclear processes such as gene expression and DNA repair. These findings have revealed a further important aspect of the chromatin modifications, suggesting that a proper crosstalk between chromatin and nuclear components, such as lamins or nuclear pores, is required to ensure the correct functioning of the nucleus and that this assumes a crucial role in many pathologies and diseases. Knowledge regarding the molecular mechanisms behind most of these developmental and diseaserelated defects remains incomplete; the influence of the nuclear architecture on chromatin function may provide a new perspective for understanding these phenotypes.