Kevin L Shimkus, Postdoctoral Scholar, Dept of Cellular & Molecular Physiology, College of Medicine, Penn State University, was award a PSGC Research Infrastructure minigrant for the project Establishing DEPTORs Influence on Skeletal Muscle Adaptations to Spaceflight for a period of performance that included Fall 2017 (12/21/2016 through 4/30/2018). The minigrant provided Dr. Shimkus the opportunity to characterize the role of DEPTOR (a negative regulator of mTOR, the key protein for synthesis) during various stages of mechanical load – specifically unloading, reloading, and overloading of skeletal muscle. This project studied mice under simulated spaceflight using the technique of hindlimb unloading for up to 14 days, and then followed the timecourse of recovery for an additional 14 days. Muscle samples from spaceflown mice were compared to the data generated by hindlimb unloaded animals. Overload was accomplished through synergistic ablation. The muscles of the lower leg will underwent a series of analyses to determine the role of DEPTOR in regulating muscle mass under the conditions of altered mechanical loading described.