The yeast proprotein convertase encoded by YAP3 is a glycophosphatidylinositol-anchored protein that localizes to the plasma membrane

NRC publication: Ye

The yeast proprotein convertase encoded by YAP3 is a glycophosphatidylinositol-anchored protein that localizes to the plasma membrane

NRC publication: Ye

Virulence and hyphal formation of Candida albicans require the Ste20p-like protein kinase CaCla4p

UI - 97411146NRC publication: Ye

Genetic analysis of the interface between Cdc-42p and the CRIB domain of Ste20p

Mutagenesis was used to probe the interface between the small GTPase Cdc42p and the CRIB domain motif of Ste20p. Members of a cluster of hydrophobic residues of Cdc42p were changed to alanine and/or arginine. The interaction of the wild-type and mutant proteins was measured using the two-hybrid assay; many, but not all, changes reduced interaction between Cdc42p and the target CRIB domain. Mutations in conserved residues in the CRIB domain were also tested for their importance in the association with Cdc42p. Two conserved CRIB domain histidines were changed to aspartic acid. These mutants reduced mating, as well as responsiveness to pheromone-induced gene expression and cell cycle arrest, but did not reduce in vitro the kinase activity of Ste20p. GFP-tagged mutant proteins were unable to localize to sites of polarized growth. In addition, these point mutants were synthetically lethal with disruption of CLA4 and blocked the Ste20p-Cdc42p two-hybrid interaction. Compensatory mutations in Cdc42p that reestablished the two-hybrid association with the mutant Ste20p CRIB domain baits were identified. These mutations improved the pheromone responsiveness of cells containing the CRIB mutations, but did not rescue the lethality associated with the CRIB mutant CLA4 deletion interaction. These results suggest that the Ste20p-Cdc42p interaction plays a direct role in Ste20p kinase function and that this interaction is required for efficient activity of the pheromone response pathway.NRC publication: Ye