Unfolded protein response in Drosophila: why another model can make it fly

The unfolded protein response (UPR) is an intracellular signaling pathway that is activated in response to stress in the endoplasmic reticulum (ER). UPR can effectively cope with stress by reducing the amount of misfolded protein overload in this subcellular organelle. Significantly, ER-stress is associated with various neurodegenerative disorders, diabetes and cancer, where UPR affects the course of disease manifestation in many cases. While significant progress has been made in various experimental systems over the years, suitable models for in vivo analyses of UPR and disease remain scarce. In this regard, recent developments of Drosophila markers and genetic tools for UPR studies provide powerful means to investigate the connection between UPR and disease in vivo. Here, we review the molecular components of the Drosophila UPR as well as the disease models that may be affected by this signaling pathway.