The S-HT3B subunit is a major determinant of serotonin-receptor function

Paul A. Davies, Marco Pistis, Michael C. Hanna, John A. Peters, Jeremy J. Lambert, Tim G. Hales, Ewen F. Kirkness

Research output: Contribution to journalArticlepeer-review

495 Citations (Scopus)


The neurotransmitter serotonin (5-hydroxytryptamine or 5-HT) mediates rapid excitatory responses through ligand-gated channels (5-HT3 receptors). Recombinant expression of the only identified receptor subunit (5-HT3A) yields functional 5-HT3 receptors1. However, the conductance of these homomeric receptors (sub-picosiemens) is too small to be resolved directly, and contrasts with a robust channel conductance displayed by neuronal 5-HT3 receptors (9-17 pS)2-7. Neuronal 5-HT3 receptors also display a permeability to calcium ions and a current-voltage relationship that differ from those of homomeric receptors3-5,8. Here we describe a new class of 5-HT3-receptor subunit (5-HT3B). Transcripts of this subunit are co-expressed with the 5-HT3A subunit in the amygdala, caudate and hippocampus. Heteromeric assemblies of 5-HT3A and 5-HT3B subunits display a large single-channel conductance (16 pS), low permeability to calcium ions, and a current-voltage relationship which resembles that of characterized neuronal 5-HT3 channels. The heteromeric receptors also display distinctive pharmacological properties. Surprisingly, the M2 region of the 5-HT3B subunit lacks any of the structural features that are known to promote the conductance of related receptors. In addition to providing a new target for therapeutic agents, the 5-HT3B subunit will be a valuable resource for defining the molecular mechanisms of ion-channel function.

Original languageEnglish
Pages (from-to)359-363
Number of pages5
Issue number6717
Publication statusPublished - 28 Jan 1999

ASJC Scopus subject areas

  • Medicine(all)
  • General


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