Molecular quantification of S accharomyces cerevisiae α‐pheromone secretion

S accharomyces cerevisiae yeast cells court each other by producing an attractive sex pheromone specific to their mating type. Cells detect the sex pheromone from potential mates using a well‐defined intracellular signalling cascade that has become a model for studying signal transduction. In contrast, the factors contributing to the production of pheromone itself are poorly characterized, despite the widespread use of the S . cerevisiae α‐pheromone secretion pathway in industrial fungal protein expression systems. Progress in understanding pheromone secretion has been hindered by a lack of a precise and quantitative pheromone production assay. Here, we present an ELISA ‐based method for the quantification of α‐pheromone secretion. In the absence of pheromone from the opposite mating type, we found that each cell secretes over 550 mature α‐pheromone peptides per second; 90% of this total was produced from MF α1. The addition of a ‐pheromone more than doubled total α‐pheromone secretion. This technique offers several improvements on current methods for measuring α‐pheromone production and will allow detailed investigation of the factors regulating pheromone production in yeast.