Regulated resource reallocation is transcriptionally hard wired into the yeast stress response.

Many organisms maintain generalized stress responses activated by adverse conditions. Although details vary, a common theme is the redirection of transcriptional and translational capacity away from growth-promoting genes and toward defense genes. Yet the precise roles of these coupled programs are difficult to dissect.

Modeling single-cell phenotypes links yeast stress acclimation to transcriptional repression and pre-stress cellular states.

Stress defense and cell growth are inversely related in bulk culture analyses; however, these studies miss substantial cell-to-cell heterogeneity, thus obscuring true phenotypic relationships. Here, we devised a microfluidics system to characterize multiple phenotypes in single yeast cells over time before, during, and after salt stress. The system measured cell and colony size, growth rate, and cell-cycle phase along with nuclear trans-localization of two transcription factors: stress-activated Msn2 that regulates defense genes and Dot6 that represses ribosome biogenesis genes during an active stress response.

Breadth and Specificity in Pleiotropic Protein Kinase A Activity and Environmental Responses.

Protein Kinase A (PKA) is an essential kinase that is conserved across eukaryotes and plays fundamental roles in a wide range of organismal processes, including growth control, learning and memory, cardiovascular health, and development. PKA mediates these responses through the direct phosphorylation of hundreds of proteins-however, which proteins are phosphorylated can vary widely across cell types and environmental cues, even within the same organism. A major question is how cells enact specificity and precision in PKA activity to mount the proper response, especially during environmental changes in which only a subset of PKA-controlled processes must respond.

Opposing functions of the Hda1 complex and histone H2B mono-ubiquitylation in regulating cryptic transcription in Saccharomyces cerevisiae.

Maintenance of chromatin structure under the disruptive force of transcription requires cooperation among numerous regulatory factors. Histone post-translational modifications can regulate nucleosome stability and influence the disassembly and reassembly of nucleosomes during transcription elongation. The Paf1 transcription elongation complex, Paf1C, is required for several transcription-coupled histone modifications, including the mono-ubiquitylation of H2B.