Atlastin regulates lipid-droplet in Drosophila melanogaster fat bodies. Han Lee¹, Diana Jin², Yi Guo². 1) Dept of Neurobiology of Disease, Mayo Graduate School, Rochester, MN; 2) Dept of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN.

   Lipid droplet (LD) is the cellular energy storage hub in most cells. Neutral lipid synthesis enzymes mainly reside in the endoplasmic reticulum (ER). The newly synthesized triglycerides and sterol esters are packed into cytosolic LDs and bud off the ER membrane leaflet as proposed in the budding model. How the ER morphology affects LD formation and expansion and in which of the specific ER domain LD forms are largely unknown. We have identified that ER tubular network regulating gene, atlastin, is important in controlling LD size in Drosophila fat bodies. Fat body specific atlastin knockdown dramatically altered ER morphology, reduced whole body fat storage. As a consequence, these flies are much more sensitive to starvation challenge. Taken together, these results show that, Drosophila atlastin has a pronounced effect on LD size and energy homeostasis of the whole organism.