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Larvae of the small white butterfly, Pieris rapae , express a novel serotonin receptor
Author(s) -
Qi YiXiang,
Xia RenYing,
Wu YaSu,
Stanley David,
Huang Jia,
Ye GongYin
Publication year - 2014
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/jnc.12940
Subject(s) - octopamine (neurotransmitter) , biology , 5 ht receptor , receptor , serotonin , receptor antagonist , pieris rapae , g protein coupled receptor , serotonin antagonists , neurotransmitter , pharmacology , antagonist , biochemistry , botany , larva
The biogenic amine serotonin ( 5‐hydroxytryptamine, 5‐HT) is a neurotransmitter in vertebrates and invertebrates. It acts in regulation and modulation of many physiological and behavioral processes through G‐protein‐coupled receptors. Five 5‐HT receptor subtypes have been reported in Drosophila that share high similarity with mammalian 5‐HT 1A , 5‐HT 1B , 5‐HT 2A , 5‐HT 2B , and 5‐HT 7 receptors. We isolated a cDNA ( Pr5‐HT 8 ) from larval Pieris rapae , which shares relatively low similarity to the known 5‐HT receptor classes. After heterologous expression in HEK293 cells, Pr5‐HT 8 mediated increased [Ca 2+ ] i in response to low concentrations (< 10 nM) of 5‐HT. The receptor did not affect [ cAMP ] i even at high concentrations (> 10 μM) of 5‐HT. Dopamine, octopamine, and tyramine did not influence receptor signaling. Pr5‐HT 8 was also activated by various 5‐HT receptor agonists including 5‐methoxytryptamine, (±)‐8‐Hydroxy‐2‐(dipropylamino) tetralin, and 5‐carboxamidotryptamine. Methiothepin, a non‐selective 5‐HT receptor antagonist, activated Pr5‐HT 8 . WAY 10635, a 5‐HT 1A antagonist, but not SB‐269970, SB‐216641, or RS‐127445, inhibited 5‐HT‐induced [Ca 2+ ] i increases. We infer that Pr5‐HT 8 represents the first recognized member of a novel 5‐HT receptor class with a unique pharmacological profile. We found orthologs of Pr5‐HT 8 in some insect pests and vectors such as beetles and mosquitoes, but not in the genomes of honeybee or parasitoid wasps. This is likely to be an invertebrate‐specific receptor because there were no similar receptors in mammals.We isolated a cDNA ( Pr5‐HT 8 ) from larval Pieris rapae , which shares relatively low similarity to the known GPCRs. After heterologous expression in HEK293 cells, Pr5‐HT 8 mediated increased [Ca 2+ ] i in response to low concentrations (< 10 nM) of 5‐HT and various 5‐HT receptor agonists. We found orthologs of Pr5‐HT 8 in some insect pests and vectors such as beetles and mosquitoes, but not in the genomes of honeybee, parasitoid wasps, or mammals.