SLC38A2 and pulmonary hypertension, primary, 1: Consistent with these reports, in the current study mTORC1 signaling activity was reduced, Nedd4-2 protein expression increased and ubiquitination of SNAT2 and LAT1 were higher in FGR PHT cells and restoration of mTORC1 signaling by DEPTOR normalization in FGR reversed all these changes.