Cryo-EM structures of rho 1 GABA A receptors with antagonist and agonist drugs.
Fan, C., Cowgill, J., Howard, R.J., Lindahl, E.(2025) Nat Commun 16: 7077-7077
- PubMed: 40750757 
- DOI: https://doi.org/10.1038/s41467-025-61932-6
- Primary Citation of Related Structures:  
9FRB, 9FRE, 9FRF, 9FRG, 9FRH, 9FRI - PubMed Abstract: 
The family of ρ-type GABA A receptors includes potential therapeutic targets in several neurological conditions, and features distinctive pharmacology compared to other subtypes. Here we report four cryo-EM structures with previously unresolved ligands, electrophysiology recordings, and molecular dynamics simulations to characterize binding and conformational impact of the drugs THIP (a non-opioid analgesic), CGP36742 (a phosphinic acid) and GABOB (an anticonvulsant) on a human ρ1 GABA A receptor. A distinctive binding pose of THIP in ρ1 versus α4β3δ GABA A receptors offers a rationale for its inverse effects on these subtypes. CGP36742 binding is similar to the canonical ρ-type inhibitor TPMPA, supporting a shared mechanism of action among phosphinic acids. Binding of GABOB is similar to GABA, but produces a mixture of partially-locked and desensitized states, likely underlying weaker agonist activity. Together, these results elucidate interactions of a ρ-type GABA A receptor with therapeutic drugs, offering mechanistic insights and a basis for further pharmaceutical development.
Organizational Affiliation: 
Department of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Solna, Sweden. chf4001@kth.se.