Novel Saccharomyces Cerevisiae mutant strains are provided for producing human parathyroid hormone. The novel strains acre genetically disrupted in at least one of the genes encoding the yapsin family of proteases Yapsin 1, Yapsin 2 and Yapsin 3 and harbor a human parathyroid hormone gene in their genomes. Culturing the novel strains results in the secretion of intact hPTH into culture media at high yield.