COQ1 overexpression in Saccharomyces cerevisiae results in increased levels of isoprenoids

LAURA CAMESASCA; MINTEGUIAGA M; FARIÑA L; VALENTINA SALZMAN; FRANCISCO CARRAU; PABLO S. AGUILAR; CARINA GAGGERO

Boston

Congreso; 114th General Meeting, American Society for Microbiology; 2014

ASM

Terpenes or isoprenoids are compounds synthesized from isoprene precursors, mainly produced by plants and utilized in the production of medicines, food additives, fragrances, pesticides, disinfectants and recently, additives for biofuels. In a previous work (FEMS Microbiol. Lett. 243:107), we have demonstrated that native Saccharomyces cerevisiae strains can synthesize terpenes de novo in a chemically defined medium that simulates a grape must but does not contain any plant precursor. We proposed that the hexaprenyl pyrophosphate synthetase Coq1p might be involved in isoprenoid biosynthesis although its currently known function in yeast is to catalyze the first step in ubiquinone (coenzyme Q) biosynthesis (J. Biol. Chem. 280:2676). Fig 1. Isoprenoid biosynthesis in eukaryotes In this communication, working in a BY4743 genetic context and analyzing isoprenoids by GC-MS, we show that when COQ1 is overexpressed from a high-copy number plasmid, the levels of the monoterpene linalol increase 18% and the sesquiterpenes nerolidol and farnesol increase 33% and 22%, respectively, when compared to isoprenoid levels from the same strain carrying an empty vector. The concentration of linalol reaches 14 ug/L while nerolidol and farnesol concentrations reach 300 ug/L. When COQ1 is either overexpressed from a low-copy number plasmid or when the COQ1 chromosomal promoter is exchanged by a constitutive GPD1 promoter, the levels of these isoprenoids diminish, concomitantly with lower levels of Coq1p. Isoprenoid levels in the presence of an empty vector are higher than in the absence of a plasmid, probably due to the physiological burden that a plasmid imposes on the cells. We demonstrate that it is possible to modulate the levels of isoprenoids that S. cerevisiae can produce in the absence of plant genes or precursors.