GPR65 (TDAG8), a Lysophospholipid/Lysosphingolipid Receptor, is a molecular target for psychosine, a toxic lipid formed by the breakdown of galactosylceramide (cerebroside). A build-up of psychosine, caused by the lack of galactosylceramidase, results in the death of the myelin-synthesizing cells, oligodendrocytes, which is associated with Krabbe disease. Recent evidence suggests that GPR65 is one of the proton-sensing GPCRs coupling to adenylyl cyclase and psychosine and its related lysosphingolipids behave as if they were antagonists against protein-sensing receptors, including TDAG8, GPR4 and OGR1 (Wang et al. 2004.) References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804