Isolation and functional expression of an animal geranyl diphosphate synthase and its role in bark beetle pheromone biosynthesis

Abstract

Geranyl diphosphate synthase (GPPS) catalyzes the condensation of dimethylallyl diphosphate and isopentenyl diphosphate to form geranyl diphosphate. Geranyl diphosphate is the precursor of monoterpenes, a large family of natural occurring C 10 compounds predominately found in plants. Similar to plants but unique to animals, some bark beetle genera (Coleoptera: Scolytidae) produce monoterpenes that function in intraspecific chemical communication as aggregation and dispersion pheromones. The release of monoterpene aggregation pheromone mediates host colonization and mating. It has been debated whether these monoterpene pheromone components are derived de novo through the mevalonate pathway or result from simple modifications of dietary precursors. The data reported here provide conclusive evidence for de novo biosynthesis of monoterpene pheromone components from bark beetles. We describe GPPS in the midgut tissue of pheromone-producing male Ips pini. GPPS expression levels are regulated by juvenile hormone III, similar to other mevalonate pathway genes involved in pheromone biosynthesis. In addition, GPPS transcript is almost exclusively expressed in the anterior midgut of male I. pini, the site of aggregation pheromone biosynthesis. The recombinant enzyme was functionally expressed and produced geranyl diphosphate as its major product. The threedimensional model structure of GPPS shows that the insect enzyme has the sequence structural motifs common to E-isoprenyl diphosphate synthases.isoprenyl diphosphate synthase ͉ monoterpene biosynthesis ͉ ipsdienol

Frontalin pheromone biosynthesis in the mountain pine beetle, Dendroctonus ponderosae , and the role of isoprenyl diphosphate synthases

“…XP_971444), C. fumiferana (20), and D. melanogaster (21), respectively. DponGPPS/FPPS and DponGGPPS shared 28% and 16% amino acid identity, respectively, with the GPPS/myrcene synthase (IpinGPPS/ MS) from I. pini (13). We found no evidence for an ortholog of this unique I. pini gene (14) in the genome or transcriptome of MPB.…”

“…In addition, an ortholog to the I. pini GPPS/MS (13) could not be found in the MPB genome (22) or in the MPB, SPB, or WPW transcriptome assemblies (NCBI TSA accession no. GAEO00000000) (25,26), reinforcing the unique role that IpinGPPS/MS plays in pheromone biosynthesis in I. pini (13,14).…”

“…These isoprenyl diphosphates are biosynthesized from the five-carbon precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) by the isoprenyl diphosphate synthases (IDSs) GPP synthase (GPPS), FPP synthase (FPPS), and GGPP synthase (GGPPS). However, it is not known which of these isoprenyl diphosphates is used as a precursor in frontalin biosynthesis.A few IDSs have been characterized in Coleoptera, including an FPPS from the cotton boll weevil (Anthonomus grandis) (11), a GPPS/FPPS from the horseradish leaf beetle (Phaedon cochleariae) (12), and a unique GPPS from the pine engraver beetle (Ips pini) that also produces myrcene (13,14). To assess their importance in pheromone biosynthesis, we identified and functionally characterized two IDSs in MPB.…”

“…A few IDSs have been characterized in Coleoptera, including an FPPS from the cotton boll weevil (Anthonomus grandis) (11), a GPPS/FPPS from the horseradish leaf beetle (Phaedon cochleariae) (12), and a unique GPPS from the pine engraver beetle (Ips pini) that also produces myrcene (13,14). To assess their importance in pheromone biosynthesis, we identified and functionally characterized two IDSs in MPB.…”

An epoxide hydrolase involved in the biosynthesis of an insect sex attractant and its use to localize the production site

“…Other approaches studied the endocrine regulation of pheromone biosynthesis (8,12) and aimed at the characterization of biosynthetic enzymes (4,5,13). The tremendous progress of molecular methods during the past years and the availability of genome sequences of various model organisms shifted the interests of researchers more and more toward the genes involved in pheromone biosynthesis (14)(15)(16)(17)(18)(19)(20). Particularly, the use of RNA interference (RNAi)-mediated gene silencing and in situ RT-PCR has demonstrated the usefulness of these cutting edge tools for insect pheromone research, because they allow both the unequivocal assignment of gene function in vivo and cell localization of biosynthetic pathways within the organism (21)(22)(23).…”