 While the intricate functions of the Ragulator-Rag Complex are not fully understood, it is known that the Ragulator-Rag Complex associates with the lysosome and plays a key role in mTOR (mammalian target of rapamycin) signaling regulation.mTOR signaling is sensitive to amino acid concentrations in the cytoplasm of the cell, and the Ragulator complex works to detect amino acid concentration and transmit signals that activate, or inhibit, mTORC1.The Ragulator, along with the Rag GTPases and v-ATPases, are part of an amino acid identifying pathway, and are necessary for the localization of the mTORC1 to the lysosome surface.