Preparing the structural view…
The 3D view could not be loaded.
Return to the MSCA impact pageDrag to rotate · scroll or pinch to zoom
01 / 03 · The receptor
A serotonin receptor at the cell membrane
The 5-hydroxytryptamine (serotonin) receptor subtype 2A, abbreviated 5-HT2A, is a serotonin-responsive G-protein-coupled receptor embedded in the cell membrane. Psilocin binds within its orthosteric pocket, located between the receptor’s transmembrane helices. This interaction can stabilise receptor conformations that promote intracellular signalling.
This view shows an experimentally determined, psilocin-bound structure (PDB 9AS8): a static molecular arrangement, not the process of ligand binding or receptor activation. G-protein partners are omitted here and shown on slide 3; the stabilising antibody and cell membrane are omitted throughout.
Follow the bound ligand
Psilocin occupies a pocket within the receptor. Select the small ligand to focus the view.
Experimental coordinates from PDB 9AS8. Cartoon geometry is a representation of the resolved backbone; missing regions are not reconstructed.
Methods & sources
Experimental structure: PDB 9AS8, human 5-HT2A receptor bound to psilocin with an engineered mini-Gq-containing heterotrimer and stabilising scFv16; cryo-EM, 2.54 Å. Gumpper et al. (2025), The structural diversity of psychedelic drug actions revealed.
Representation: receptor chain A, engineered Gα chain B, Gβ chain C and Gγ chain D. Chain E (scFv16) is omitted. Protein cartoons are generated with Molecular Nodes from resolved backbone coordinates. Psilocin (component 91Q) retains all 15 deposited heavy atoms and 16 unique covalent connections from the PDB CONECT records. Bond order is not illustrated. Carbon is gold, nitrogen blue and oxygen red; hydrogen atoms are hidden.
Binding pocket: whole chain-A residues with a minimum heavy-atom distance of 4.0 Å or less to a psilocin heavy atom. Within-residue sticks use covalent-radius connectivity; they do not show hydrogen bonds or interaction energies. No unresolved loops, membrane lipids or molecular dynamics are reconstructed.
Signalling context: 9AS8 contains a Gi2–mini-Gq chimeric construct. Gq is not the only possible 5-HT2A coupling route: a separate psilocin–Gi complex is deposited as PDB 9LL8 (Xu et al., 2026). That separate structure is not displayed here. Structural coupling is not evidence of a complete downstream mechanism in humans.
Reuse: PDB coordinate data are CC0; cite the entry and structure authors. Prepared with Blender and Molecular Nodes; displayed with Three.js. Structural provenance · Three.js licence.