Genetic dissection of the signaling pathway required for the cell wall integrity checkpoint.

The cell wall integrity checkpoint monitors synthesis of cell wall materials during the cell cycle. Upon perturbation of cell wall synthesis, the cell wall integrity checkpoint is activated, downregulating Clb2 transcription. Here, we identified genes involved in this checkpoint by genetic screening of deletion mutants.

Systematic analysis of Ca homeostasis in based on chemical-genetic interaction profiles.

We investigated the global landscape of Ca homeostasis in budding yeast based on high-dimensional chemical-genetic interaction profiles. The morphological responses of 62 Ca-sensitive () mutants were quantitatively analyzed with the image processing program CalMorph after exposure to a high concentration of Ca After a generalized linear model was applied, an analysis of covariance model was used to detect significant Ca- interactions. We found that high-dimensional, morphological Ca- interactions were mixed with positive (86%) and negative (14%) chemical-genetic interactions, whereas one-dimensional fitness Ca- interactions were all negative in principle.

The fission yeast stress-responsive MAPK pathway promotes meiosis via the phosphorylation of Pol II CTD in response to environmental and feedback cues.

The RRM-type RNA-binding protein Mei2 is a master regulator of meiosis in fission yeast, in which it stabilizes meiosis-specific mRNAs by blocking their destruction. Artificial activation of Mei2 can provoke the entire meiotic process, and it is suspected that Mei2 may do more than the stabilization of meiosis-specific mRNAs. In our current study using a new screening system, we show that Mei2 genetically interacts with subunits of CTDK-I, which phosphorylates serine-2 residues on the C-terminal domain of RNA polymerase II (Pol II CTD).