Nuclear Structure in Budding yeast: Impacts of Chromatin Organization and Gene Expression

Abstract

The genome of a eukaryotic cell tightly packed within the nucleus with a high degree of structural organization. Two mechanisms accounting for nuclear structure and the dynamics of subnucler organization in S. cerevisiae are presented within. First, two powerful genetic screens identify requirements for the RSC chromatin-remodeling complex in maintaining nuclear morphology. The major NE-malformations observed in rsc mutants likely result from aberrant transcription and lipid homeostasis. Second, nuclear organization of transcriptional events in response to osmotic stress in S. cerevisiae involves the relocalization of the Hot1 transcription factor to foci that overlap with corresponding target genes. Casein Kinase II negatively regulates Hot1 localization to foci, and also leads to a reduced transcriptional response. These results suggest that the nuclear organization of transcription events impact the stochastic activity of environmentally induced genes. In conclusion, both chromatin organization and transcription events result in dynamic alterations in nuclear structure impacting the output of the genome.