An Analog-sensitive Version of the Protein Kinase Slt2 Allows Identification of Novel Targets of the Yeast Cell Wall Integrity Pathway.

The yeast cell wall integrity MAPK Slt2 mediates the transcriptional response to cell wall alterations through phosphorylation of transcription factors Rlm1 and SBF. However, the variety of cellular functions regulated by Slt2 suggests the existence of a significant number of still unknown substrates for this kinase. To identify novel Slt2 targets, we generated and characterized an analog-sensitive mutant of Slt2 (Slt2-as) that can be specifically inhibited by bulky kinase inhibitor analogs.

Differential genetic interactions of yeast stress response MAPK pathways.

Genetic interaction screens have been applied with great success in several organisms to study gene function and the genetic architecture of the cell. However, most studies have been performed under optimal growth conditions even though many functional interactions are known to occur under specific cellular conditions. In this study, we have performed a large-scale genetic interaction analysis in Saccharomyces cerevisiae involving approximately 49 × 1,200 double mutants in the presence of five different stress conditions, including osmotic, oxidative and cell wall-altering stresses.

The Salmonella Typhimurium effector SteC inhibits Cdc42-mediated signaling through binding to the exchange factor Cdc24 in Saccharomyces cerevisiae.

Intracellular survival of Salmonella relies on the activity of proteins translocated into the host cell by type III secretion systems (T3SS). The protein kinase activity of the T3SS effector SteC is required for F-actin remodeling in host cells, although no SteC target has been identified so far. Here we show that expression of the N-terminal non-kinase domain of SteC down-regulates the mating and HOG pathways in Saccharomyces cerevisiae.

A yeast-based genetic screen for identification of pathogenic Salmonella proteins.

Salmonella uses type III secretion systems (TTSS) to deliver pathogenic proteins into the host cells. These translocated effectors induce bacterial internalization and intracellular proliferation by targeting important cellular processes that are conserved among eukaryotes. Here, we assessed the feasibility of performing a genetic screen in yeast to identify novel Salmonella effectors, by searching for genes that produce toxicity when expressed in this model system.