Our previous study demonstrated that Boleophthalmus pectinirostris MOSPD2 (BpMOSPD2) is the receptor of BpLEAP2. In subsequent experiments, we observed that BpMOSPD2 undergoes membrane translocation in the presence of BpLEAP2. However, BpMOSPD2 contains only five amino acids in its intracellular region, which greatly limits its intracellular activity. Therefore, we employed a combined immunoprecipitation–mass spectrometry (IP-MS) approach to identify potential intracellular proteins associated with BpMOSPD2, aiming to better explain the membrane translocation process of BpMOSPD2 in the presence of BpLEAP2.