Lysosomal integral membrane protein that regulates the localization and activity of mTORC1, a signaling complex promoting cell growth in response to growth factors, energy levels, and amino acids. Interacts with Rag GTPases and increases the lysosomial localization and activity of Rag GTPases and thereby regulates mTORC1 translocation and activity in lysosome. Involved in the regulation of lysosomal morphology and autophagy (By similarity). Acts also as a negative regulator of osteoclast activity (By similarity). Acts also as a negative regulator of osteoclast activity. Belongs to the GPR137 family.