Alpha-factor-directed synthesis and secretion of mature foreign proteins in Saccharomyces cerevisiae.

Saccharomyces cerevisiae cells were transformed with plasmids containing hybrid genes in which the sequence encoding mature human epidermal growth factor was joined to sequences encoding the leader region (preprosegment) of the precursor of the yeast mating pheromone alpha-factor. These cells accurately process the hybrid protein and efficiently secrete authentic biologically active human epidermal growth factor into the medium.