A diterpene synthase from the sandfly Lutzomyia longipalpis produces the pheromone sobralene

Abstract

The phlebotomine sandfly, Lutzomyia longipalpis , a major vector of the Leishmania parasite, uses terpene pheromones to attract conspecifics for mating. Examination of the L. longipalpis genome revealed a putative terpene synthase (TPS), which—upon heterologous expression in, and purification from, Escherichia coli —yielded a functional enzyme. The TPS, termed Ll TPS, converted geranyl diphosphate (GPP) into a mixture of monoterpenes with low efficiency, of which β-ocimene was the major product. ( E,E )-farnesyl diphosphate (FPP) principally produced small amounts of ( E )-β-farnesene, while ( Z,E )- and ( Z,Z )-FPP yielded a mixture of bisabolene isomers. None of these mono- and sesquiterpenes are known volatiles of L. longipalpis . Notably, however, when provided with ( E,E,E )-geranylgeranyl diphosphate (GGPP), Ll TPS gave sobralene as its major product. This diterpene pheromone is released by certain chemotypes of L. longipalpis , in particular those found in the Ceará state of Brazil. Minor diterpene components were also seen as products of the enzyme that matched those seen in a sandfly pheromone extract.