Cloning and Functional Characterization of Octβ2-Receptor and Tyr1-Receptor in the Chagas Disease Vector, Rhodnius prolixus

Abstract

Octopamine and tyramine, both biogenic amines, are bioactive chemicals important in diverse physiological processes in invertebrates. In insects, octopamine and tyramine operate analogously to epinephrine and norepinephrine in the vertebrates. Octopamine and tyramine bind to G-protein coupled receptors (GPCRs) leading to changes in second messenger levels and thereby modifying the function in target tissues and insect behavior. In this paper, we report the cDNA sequences of two GPCRs, RhoprOctβ2-R, and RhoprTyr1-R, have been cloned and functionally characterized from Rhodnius prolixus. Octopamine and tyramine each activate RhoprOctβ2-R and RhoprTyr1-R in a dose-dependent manner. Octopamine is one order of magnitude more potent than tyramine in activating RhoprOctβ2-R. Tyramine is two orders of magnitude more potent than octopamine in activating RhoprTyr1-R. Phentolamine and gramine significantly antagonize RhoprOctβ2-R, whereas yohimbine and phenoxybenzamine are effective blockers of RhoprTyr1-R. The transcripts of both receptors are enriched in the central nervous system (CNS) and are expressed throughout the adult female reproductive system. It has been shown in other insects that Octβ2-R is essential for processes such as ovulation and fertilization. We previously reported that octopamine and tyramine modulate oviducts and bursa contractions in R. prolixus. Our data confirm the importance of octopamine and tyramine signaling in the reproductive system of R. prolixus.

Tyramine receptor drives olfactory response to (E)-2-decenal in the stink bug Halyomorpha halys

“…The HhTAR1 coding region was cloned and expressed into HEK 293 cells and the recombinant receptor tested for its ability to respond to known TAR1 ligands. In the calcium mobilization assay TA was significantly more potent than OA, as observed for other TAR1s (Gross et al, 2015;Hana & Lange, 2017a;Finetti et al, 2020). Furthermore, the effect of TA was sensitive to the antagonist yohimbine, as observed in other orthologous TAR1s (Saudou et al, 1990;Gross et al, 2015;Hana & Lange, 2017a;Finetti et al, 2020).…”

“…In the calcium mobilization assay TA was significantly more potent than OA, as observed for other TAR1s (Gross et al, 2015;Hana & Lange, 2017a;Finetti et al, 2020). Furthermore, the effect of TA was sensitive to the antagonist yohimbine, as observed in other orthologous TAR1s (Saudou et al, 1990;Gross et al, 2015;Hana & Lange, 2017a;Finetti et al, 2020). Other biogenic amines, such as dopamine and adrenaline, were not able to activate HhTAR1, also shown also in R. microplus TAR1 (Gross et al, 2015).…”

“…The receptor, called Tyr-dro, showed higher affinity (12-fold) for TA than for OA and was mainly expressed in heads. Since then the same receptor has been characterized in several orders of insects: Hymenoptera (Blenau et al, 2000), Orthoptera (Poels et al, 2001), Lepidoptera (Ohta et al, 2003), Hemiptera (Hana & Lange, 2017a) and Diptera (Finetti et al, 2020). Several physiological and behavioral functions are controlled by TAR1, including olfaction.…”

PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana

“…A comparison of the PeaTAR1B amino-acid sequence with NCBI databases identified several orthologous type 1 tyramine receptors. The highest amino acid identity (ID) and similarity (S) was found with the RpTAR1 receptor of the blood-sucking bug Rhodnius prolixus ([ 78 ]; ID 65.6%, S 74.9%) and the LmTAR1 receptor of the migratory locust Locusta migratoria ([ 60 ]; ID 64.5%, S 74.1%). Homology was also pronounced to tyramine receptors of the lepidopterans Agrotis ipsolon ([ 79 ]; ID 59.0%, S 72.7%), Heliothis virescens ([ 80 ]; ID 60.0%, S 72.3%), Bombyx mori ([ 62 , 63 ]; ID 58.6%, S 71.3%) and Papilio xuthus ([ 81 ]; ID 57,0%, S 70.7%), the PeaTAR1A receptor from P. americana ([ 70 ]; ID 58.4%, S 71.3%), and type 1 tyramine receptors of the honeybee Apis mellifera ([ 61 , 64 ]; ID 54.1%, S 65.9%) and Drosophila melanogaster ([ 59 ]; ID 47.1%, S 59.0%).…”

Modulation of neuromuscular synapses and contraction inDrosophila3rd instar larvae

“…In insects, OA plays key roles in desensitizing sensory inputs, initiating and maintaining rhythmic behaviors such as flight, and regulating complex social behaviors such as fighting, courtship and reproduction (e.g. Brembs, Christiansen, Pfl€ uger, & Duch, 2007;Certel, Savella, Schlegel, & Kravitz, 2007;Dierick, 2008;Giurfa, 2006;Hana & Lange, 2017a, 2017bHoyer et al, 2008;Rezaval, Nojima, Neville, Lin, & Goodwin, 2014;Suver, Mamiya, & Dickinson, 2012;Wasserman et al, 2015). Most or all of these functions involve effects of OA within the CNS.…”