B96Bom encodes a Bombyx mori tyramine receptor negatively coupled to adenylate cyclase

Abstract

A cDNA encoding a biogenic amine receptor (B96Bom) was isolated from silkworm (Bombyx mori) larvae, and the ligand response of the receptor stably expressed in HEK-293 cells was examined. Tyramine (TA) at 0.1-100 micro m reduced forskolin (10 micro m)-stimulated intracellular cAMP levels by approximately 40%. The inhibitory effect of TA at 1 micro m was abolished by yohimbine and chlorpromazine (each 10 micro m). Although octopamine (OA) also reduced the cAMP levels, the potency was at least two orders of magnitude lower than that of TA. Furthermore, unlabelled TA (IC50 = 5.2 nm) inhibited specific [3H]TA binding to the membranes of B96Bom-transfected HEK-293 cells more potently than did OA (IC50 = 1.4 micro m) and dopamine (IC50 = 1.7 micro m). Taken together with the result of phylogenetic analysis, these findings indicate that the B96Bom receptor is a B. mori TA receptor, which is negatively coupled to adenylate cyclase. The use of this expression system should facilitate physiological studies of TA receptors as well as structure-activity studies of TA receptor ligands.

Trace amine-associated receptor 1—Family archetype or iconoclast?

“…In addition to providing the means by which to further characterize Drosophila OCT/TYR GPCRs these clones served as nucleic acid hybridization probes that were used to identify and isolate homologous receptor sequences from several invertebrate species (Vanden Broeck et al, 1995;von Nickisch-Rosenegk et al, 1996;Gerhardt et al, 1997a;Gerhardt et al, 1997b;Reale et al, 1997;Baxter & Barker, 1999;Blenau et al 2000;Chang et al, 2000;Poels et al, 2001;Rex & Komuniecki, 2002;Ohta et al, 2003;Farooqui et al, 2003;Farooqui et al, 2004;Grohmann et al, 2003;Bischof & Enan, 2004;Balfanz, 2005;Molaei et al, 2005;Mustard et al 2005;Rex et al, 2005;Dacks et al, 2006). These clones have also been instrumental in identifying the important structural features that particpate in the binding of ligand and coupling of the the receptor to its effectors (Chatwin et al, 2003;Huang, 2003;Ohta et al, 2004).…”

The cloning of one putative octopamine receptor and two putative serotonin receptors from the tobacco hawkmoth, Manduca sexta

“…3B). Several recent studies and reviews have suggested that the two putative lepidopteran OA/tyramine receptors (von Nickisch-Rosenegk et al, 1996) are most likely tyramine receptors (Roeder, 2005;Ohta et al, 2003). Indeed, the B96Bom protein was recently isolated and functionally expressed demonstrating its ligand specificity to tyramine (Ohta et al, 2003).…”

Are Caenorhabditis elegans receptors useful targets for drug discovery: Pharmacological comparison of tyramine receptors with high identity from C. elegans (TYRA-2) and Brugia malayi (Bm4)

“…TYRA-2 and Bm4 differ by only 14 amino acids in the transmembrane regions forming the ligand-binding pocket (TM III, V, VI and VII) and both receptors also share the S1xxxxS5 motif in TM V thought to be responsible for TA binding [46]. The pharmacological profile of TYRA-2 expressed in HEK-292 cells mimicked that of TYRA-2 expressed in COS-7 cells published previously [9].…”