The structure and signalling properties of 5-HT receptors: an endless diversity?

It became evident during the course of the symposium that receptor isoforms produced by alternative splicing or mRNA editing will need to be embraced by the NC-IUPHAR scheme, yet criteria by which to judge whether these isoforms are functional, or merely the result of `leaky transcription', remain to be established.

Abstract

Fourteen different receptor subtypes[ 1 Hoyer D Martin G.R Neuropharmacology. 1997; 36: 419-428 Crossref PubMed Scopus (371) Google Scholar ]might be regarded as sufficient diversity to accommodate the wide-ranging physiological roles of 5-HT. However, it is becoming abundantly clear that , for this as for other transmitters, the concept of `receptor as gatekeeper' for a specific cellular process or event is far too restrictive. This theme was the focus for a recent symposium Advances in Serotonin Receptor Research 1 Advances in Serotonin Receptor Research, 8–10 October 1997, San Francisco, USA. . While day one of the meeting examined information derived from a structural appreciation of 5-HT receptors, day two concentrated on receptor–effector signalling with an emphasis on signal modulation, ligand-induced receptor trafficking, pleiotropic behaviour of agonists and receptor cross-talk. The last half day attempted to draw this information together in highlighting emerging new therapeutic opportunities and the impact of this increasing structural and operational diversity on classification.