TY - JOUR T1 - Edem1 activity in the fat body regulates insulin signalling and metabolic homeostasis in Drosophila JF - bioRxiv DO - 10.1101/671305 SP - 671305 AU - Himani Pathak AU - Jishy Varghese Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/01/28/671305.abstract N2 - In Drosophila nutrient status is sensed by the fat body, a functional homolog of mammalian liver and white adipocytes. The fat body conveys nutrient information to insulin-producing cells (IPCs) through humoral factors and controls systemic insulin signalling. Insulin signalling has pleiotropic functions which include the regulation of key growth and metabolic pathways. Here, we report that Edem1 (endoplasmic reticulum degradation enhancing α-mannosidase-like protein1), an endoplasmic reticulum-resident protein involved in protein quality control, acts in the fat body to regulate insulin signalling, metabolic status and starvation responses in Drosophila. Edem1 limits Drosophila TNFα Eiger activity, a fat body derived humoral factor that acts on IPCs, and maintains systemic insulin signalling in normal fed conditions. During food deprivation, Edem1 expression levels drop which aids in surviving the effects of nutrient starvation. Overall we demonstrate that Edem1 plays a crucial role in helping the organism to endure a fluctuating nutrient environment by managing insulin signalling and metabolic homeostasis. ER -