Download MendeleySubstrate and inhibitor binding of human GABA transporter 3.
Xu, H., Zhang, Y., Bai, Q., He, L., Chen, Q., Qiu, Y., Li, R., Yu, J., Zhao, J., Zhao, Y.(2025) Structure 33: 2049-2057.e5
- PubMed: 40914153
- DOI: https://doi.org/10.1016/j.str.2025.08.012
- Primary Citation of Related Structures:
9LK7, 9LK8, 9LK9 - PubMed Abstract:
GABA (g-aminobutyric acid) transporter 3 (GAT3) is primarily found in glial cells and is essential for regulating GABA homeostasis in the central nervous system by mediating GABA uptake. Consequently, GAT3 has emerged as a significant therapeutic target for the treatment of epilepsy. In this study, we present the cryoelectron microscopy (cryo-EM) structures of GAT3 bound to its substrate GABA, the selective inhibitor SNAP-5114, and in the substrate-free state. GAT3 binds to GABA in an inward-facing conformation, while SNAP-5114 occupies the GABA-binding pocket and is stabilized by extensive interactions with surrounding residues. Functional studies reveal that E66 plays a pivotal role in determining the substrate-binding mode and specificity of SNAP-5114 binding. Taken together, our study clarifies the GABA binding mechanism of GAT3 and reveals the molecular basis for the specific inhibition of SNAP-5114, offering valuable insights for developing GAT3 subtypes selective inhibitors, which hold potential as a treatment for epilepsy.
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China; Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
Organizational Affiliation:
