Open AccessSqualene epoxidase as a target for manipulation of squalene levels in the yeast S accharomyces cerevisiae
Author(s) -
Garaiová Martina,
Zambojová Veronika,
Šimová Zuzana,
Griač Peter,
Hapala Ivan
Publication year - 2014
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/1567-1364.12107
Subject(s) - squalene monooxygenase , squalene , ergosterol , terbinafine , saccharomyces cerevisiae , yeast , biology , biochemistry , biosynthesis , enzyme , microbiology and biotechnology , antifungal , itraconazole
Squalene is a valuable natural substance with several biotechnological applications. In the yeast Saccharomyces cerevisiae , it is produced in the isoprenoid pathway as the first precursor dedicated to ergosterol biosynthesis. The aim of this study was to explore the potential of squalene epoxidase encoded by the ERG1 gene as the target for manipulating squalene levels in yeast. Highest squalene levels (over 1000 μg squalene per 10 9 cells) were induced by specific point mutations in ERG1 gene that reduced activity of squalene epoxidase and caused hypersensitivity to terbinafine. This accumulation of squalene in erg1 mutants did not significantly disturb their growth. Treatment with squalene epoxidase inhibitor terbinafine revealed a limit in squalene accumulation at 700 μg squalene per 10 9 cells which was associated with pronounced growth defects. Inhibition of squalene epoxidase activity by anaerobiosis or heme deficiency resulted in relatively low squalene levels. These levels were significantly increased by ergosterol depletion in anaerobic cells which indicated feedback inhibition of squalene production by ergosterol. Accumulation of squalene in erg1 mutants and terbinafine‐treated cells were associated with increased cellular content and aggregation of lipid droplets. Our results prove that targeted genetic manipulation of the ERG1 gene is a promising tool for increasing squalene production in yeast.