Control of Drosophila Growth and Survival by the Lipid Droplet-Associated Protein CG9186/Sturkopf

Abstract

Summary: Lipid droplets (LDs) are the universal cellular storage organelles for esterified neutral lipids. The increasing number of characterized LD-associated proteins attained LDs with hitherto unexpected functions on top of their classical role as energy depot. Here, we characterize the LD-associated protein CG9186 of Drosophila by a CRISPR/Cas9-derived mutant fly line. While the mutant flies only showed a mild triacylglycerol storage phenotype, they were highly protected from desiccation stress, likely linked to a reduced locomotor activity and altered cuticular hydrocarbons. Both parameters depend on juvenile hormone (JH) signaling. Together with an observed interaction between CG9186 and JH-degrading enzymes, our results suggest that CG9186 participates in endocrine physiology regulation. In support of this hypothesis, CG9186 mutant flies show an altered expression of JH target genes and fail to adjust their developmental rate to dietary yeast-to-sugar ratio changes. Our results thus link LDs to organismic physiology regulation. : Werthebach et al. introduce the lipid droplet-associated protein CG9186/sturkopf as a component of organismic physiology regulation, which affects insulin and juvenile hormone signaling activity. Keywords: lipid droplets, physiology, Drosophila, larval developmental rate, nutrient sensing, juvenile hormone, LDAH, c2orf43, desiccation, insulin signaling