Tremerogen A-10 is an S-polyisoprenyl peptide mating pheromone secreted by the AB cells of the heterobasidiomycetous yeast Tremella mesenterica. We investigated the feasibility of the use of compactin (ML236-B), a potent inhibitor of mevalonate synthesis in mammalian cells, for the study of the mating pheromone production. Compactin specifically inhibited mevalonate synthesis of the yeast cells without affecting protein synthesis. The secretion of tremerogen A-10 was effectively blocked by the drug. Accumulation of a large precursor polypeptide (M.W. 28,000) for the mature pheromone (M.W. 1,480) in the membrane fraction of compactin-treated cells was demonstrated by immunoprecipitation of 35S-labeled proteins. The results suggested that the addition of the nonpolar residue to a polypeptide precursor is important for the production of tremerogen A-10, especially in the intracellular transport and processing of the precursor molecules.