Portal de Periódicos da CAPES

Characterization of a Novel Serotonin Receptor from Caenorhabditis elegans

1999; Wiley; Volume: 72; Issue: 4 Linguagem: Inglês

10.1046/j.1471-4159.1999.721372.x

1471-4159

Fadi F. Hamdan, Mark Ungrin, Mark Abramovitz, Paula Ribeiro,

Circadian rhythm and melatonin

Abstract: Serotonin [5‐hydroxytryptamine (5‐HT)] modulates feeding activity, egg‐laying, and mating behavior in the free‐living nematode, Caenorhabditis elegans . We have cloned a novel receptor cDNA from C. elegans (5‐HT 2Ce ) that has high sequence homology with 5‐HT 2 receptors from other species. When transiently expressed in COS‐7 cells, 5‐HT 2Ce exhibited 5‐HT binding activity and activated Ca 2+ ‐mediated signaling in a manner analogous to other 5‐HT 2 receptors. However, 5‐HT 2Ce displayed unusual pharmacological properties, which resembled both 5‐HT 2 and 5‐HT 1 ‐like receptors but did not correlate well with any of the known 5‐HT 2 subtypes. Two splice variants of 5‐HT 2Ce that differ by 48 N‐terminal amino acids were identified. The two isoforms were found to have virtually identical binding and signaling properties but differed in their levels of mRNA expression, with the longer variant being four times more abundant than the shorter species in all developmental stages tested. Taken together, the results describe two variants of a novel C. elegans 5‐HT receptor, which has some of the properties of the 5‐HT 2 family but whose pharmacological profile does not conform to any known class of receptor.