Signaling snapshots of a serotonin receptor activated by the prototypical psychedelic LSD.
Cao, C., Barros-Alvarez, X., Zhang, S., Kim, K., Damgen, M.A., Panova, O., Suomivuori, C.M., Fay, J.F., Zhong, X., Krumm, B.E., Gumpper, R.H., Seven, A.B., Robertson, M.J., Krogan, N.J., Huttenhain, R., Nichols, D.E., Dror, R.O., Skiniotis, G., Roth, B.L.(2022) Neuron 110: 3154
- PubMed: 36087581 
- DOI: https://doi.org/10.1016/j.neuron.2022.08.006
- Primary Citation of Related Structures:  
7SRQ, 7SRR, 7SRS - PubMed Abstract: 
Serotonin (5-hydroxytryptamine [5-HT]) 5-HT2-family receptors represent essential targets for lysergic acid diethylamide (LSD) and all other psychedelic drugs. Although the primary psychedelic drug effects are mediated by the 5-HT 2A serotonin receptor (HTR2A), the 5-HT 2B serotonin receptor (HTR2B) has been used as a model receptor to study the activation mechanisms of psychedelic drugs due to its high expression and similarity to HTR2A. In this study, we determined the cryo-EM structures of LSD-bound HTR2B in the transducer-free, Gq-protein-coupled, and β-arrestin-1-coupled states. These structures provide distinct signaling snapshots of LSD's action, ranging from the transducer-free, partially active state to the transducer-coupled, fully active states. Insights from this study will both provide comprehensive molecular insights into the signaling mechanisms of the prototypical psychedelic LSD and accelerate the discovery of novel psychedelic drugs.
Organizational Affiliation: 
Department of Pharmacology, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC 27599-7365, USA.