Abstact

The upregulation of transmembrane protein 175 (TMEM175) has the potential to improve Parkinson's disease (PD) by aiding in the removal of α-synuclein aggregates. Understanding the structural basis of TMEM175 agonisms is crucial for uncovering its therapeutic potential for PD. Here, we have identified the first cryo-electron microscopy (cryo-EM) structure of human TMEM175 complexes with three agonists: DCY1020, DCY1040, and TUG-891. An open state of TMEM175 is unequivocally captured, laying the groundwork for designing more effective agonists. Further investigations using surface plasmon resonance, systematic mutagenesis, whole-endolysosome patch-clamp techniques, and molecular dynamics simulations consistently revealed that DCY1020/1040 binds at the interface between two subunits, inducing an open conformation further augmented by the synergistic agonist TUG-891. Notably, these agonists facilitate the removal of pathological α-synuclein and restore functions of PD-related TMEM175 variants in neurons. Our findings provide proof of concept that drug discovery targeting TMEM175 can develop agonists capable of effectively reducing pathological α-synuclein levels in PD.