TARGETING INOSITOL LIPIDS THROUGH METABOLIC LABELLING WITH INOSITOL ANALOGS

Abstract

Myo-inositol is biosynthesized from glucose-6-phosphate or transported from culture media for inositol lipid biosynthesis. Phosphatidylinositol is the parent inositol lipid from which phosphoinositides, GPI anchors and other lipids are generated ¿ a pathway that is highly conserved amongst eukaryotes. We target inositol lipids using variations in substrate preferences of enzymes in the inositol lipid biosynthesis pathway. Azide-modified myo-inositol was synthesized with the azide moiety allowing for specific labelling with alkyne-modified reporter molecules through Azide-alkyne Huisgen cycloaddition (click chemistry). Saccharomyces cerevisiae was selected as the model organism to study the effects of inositol analogs on growth and cellular environment. Incorporation of azido-inositol into lipids was confirmed and modified lipids were tagged specifically. Changes in lipid homeostasis were observed in the presence of azido-inositol when compared with myo-inositol supplementation, although gene elements were regulated in a similar manner. Azido-inositol shows potential as a tool for studying the localization and metabolism of inositol lipids.