Quantitative Structure-Activity Relationships (QSARs) of Monoterpenoids at an Expressed American Cockroach Octopamine Receptor

Abstract

Monoterpenoids are found in essential oils from numerous plant families. Octopamine is a biogenic monoamine found within various invertebrates, including insects. Octopamine exerts its physiological effects through the activation of G-protein-coupled receptors (GPCRs). GPCRs are an under-utilized receptor target in the agrochemical industry. Here we report the expression of an octopamine receptor from the brain of the American cockroach (Periplaneta americana) inSaccharomyces cerevisiae, creating a ligand-independent histidine-auxotrophic assay. The majority of monoterpenoids acted as an inverse agonist in this system. Three QSAR models show that electronic properties are most important for monoterpenoid interaction with this octopamine receptor in this yeast assay.

Interaction of plant essential oil terpenoids with the southern cattle tick tyramine receptor: A potential biopesticide target

“…These results indicate that once tyramine activates its receptor (RmTAR1), it results in a conformation change of the receptor protein that allows these terpenoids to stabilize and enhance the signaling activity of RmTAR1. We have previously described this effect with an American cockroach octopamine receptor when this receptor is constitutively active and expressed in yeast cells [17]. Additionally, a similar modulatory response was also reported with this tyramine receptor (RmTAR1) and the amitraz metabolite (BTS 27271) [15].…”

“…While toxicity and repellency of plant essential oils and their terpenoid constituents have been recognized for some time, the precise biochemical mechanism of action has yet to be fully understood, especially in ticks. In fact, several mechanisms of toxic action have been proposed, which include the inhibition of acetylcholinesterase [14,25,31,32,35,47], activity at the g-aminobutyric acid (GABA A ) receptor [38,50,51], the nicotinic acetylcholine receptor [52], inhibition of the transient receptor potential (TRP) channels [34], octopamine receptors [9,11,17,21], and tyramine receptors [10]. While essential oils are less toxic than conventional synthetic acaricides, they can still be effective at controlling the southern cattle tick.…”

Terpenes: Natural Products for Controlling Insects of Importance to Human Health—A Structure-Activity Relationship Study

“…Gross et al [110], in a ligand-independent system, evaluated aliphatic and aromatic terpenes that acted as inverse agonists. One of the compounds tested, carvacrol, interacted with the octopamine receptor and altered the conformation and increased the affinity for the endogenous G-protein.…”

Enhanced Salmonella virulence instigated by bactivorous protozoa and investigation of putative protozoan G protein-coupled receptors associated with bacterial engulfment

“…In these particular yeast strains, Fus1 controls the expression of His3 that confers the ability to synthesize histidine de novo. Therefore, activation of a heterologously expressed GPCR results in Fus1 activation, subsequent His3 expression, and the ability to grown in histidine-deficient media [48][49][50].…”

“…Yeast heterologous expression was used to deorphanize the human β 2 adrenergic receptor as well as other mammalian GPCRs. More recently, the yeast expression system has been used to study the pharmacology of GPCRs from nematodes and arthropods [49,50]. A goal of the studies presented in this work was to utilize the yeast expression system as a tool to deorphanize putative GPCRs from protozoa.…”