Jana Molitor

Embryonic stem cells (ESCs) are characterized by their unlimited self-renewal potential and their ability to differentiate into all cells of the three germ layers. These properties make them a promising tool for medical research in various areas as for example transplantation therapies, treatment of Parkinson’s diseases and heart failure. The plastic chromatin structure in ESCs is one of the key determinants of their self-renewal and pluripotency potential. Another characteristic feature is the high expression of ATP-dependent chromatin remodeling complexes (Efroni et al., 2008; Gaspar-Maia et al., 2009; Kurisaki et al., 2005). Such complexes use hydrolysis of ATP to control nucleosome positioning and the composition of nucleosomes. In this manner they regulate the access to associated DNA during transcription, DNA-replication and DNA-repair. The chromatin-associated signals that direct this process are largely unknown. However, several lines of evidence point to an important role of histone modification by methylation and acetylation as well as the presence of histone variants that can replace canonical core histones in nucleosomes. We are interested in mechanisms by which chromatin structure is established, maintained and modified during differentiation. Therefore the targeting of chromatin remodeling complexes by histone modifications and histone variants is investigated by a combination of cell culture experiments and in vitro studies.