Expression levels of transdominant peptides and proteins in Saccharomyces cerevisiae

From libraries of peptides and protein fragments, several inhibitors that block pheromone response in Saccharomyces cerevisiae have been isolated previously. In many cases, the inhibitors are displayed as part of a scaffold, such as green fluorescent protein. Each of the inhibitors has a characteristic physiological strength or genetic penetrance. In this report, the roles of expression level and display scaffold on the activities of a subset of pheromone-response pathway inhibitors were examined. Special consideration was given to the relationship between expression levels of specific inhibitors, which may exceed 50 microM in some instances, and penetrance.