Solute carrier family 15 member A4 (SLC15A4) is a lysosome-resident amino acid/oligopeptide transporter preferentially expressed in immune cells, and plays critical roles in the pathogenesis of lupus and colitis in murine model. SLC15A4 is required for TLR7/9- or NOD1-mediated inflammatory responses through mTORC1 regulation or transporting NOD1 ligand, TriDAP, respectively. To further understand the mechanisms of SLC15A4’s action in inflammatory responses, we applied proximity-dependent biotin identification experiment (BioID) to SLC15A4, and identified a panel of proteins including mTORC1 and its regulator that associate with and/or are proximate to SLC15A4 in vivo.