Role of the map kinase sty1 and the transcription factor atf1 in euchromatin and heterochromatin dynamics in schizosaccharomyces pombe

Abstract

Eukaryotic DNA is condensed inside the nucleus, compacted into chromatin. The structure of chromatin is dynamic, and its accessibility to molecular machines such as the replication or transcription complexes can be altered depending on the level of chromatin compaction (euchromatin or heterochromatin) and the induction of specific transcription programs. In Schizosaccharomyces pombe, the MAP kinase Sty1 and the transcription factor Atf1 play a key role in the regulation of gene expression during diverse biological processes. These inducible transcriptional responses are essential to survive to different environmental changes, and phosphorylated Atf1 rules the chromatin remodeling needed to adapt and survive. Furthermore, the transcription factor Atf1 does not only affect euchromatic transcription, but also the formation and maintenance of heterochromatin. In this work, I describe the role of Sty1-mediated phosphorylation of Atf1 in different processes, both stress related or not, and the effects caused in the chromatin dynamics by this pathway. I also investigate the effect of DNA topology on nucleosome positioning at stress genes.