Abstract
G-protein-coupled receptors (GPCRs) are known to play central roles in the physiology of many organisms. Members of this seven α-helical transmembrane protein family transduce the extracellular signals and regulate intracellular second messengers through coupling to heterotrimeric G-proteins, adenylate cyclase, cAMPs, and protein kinases. As a result of the critical function of GPCRs in cell physiology and biochemistry, they not only play important roles in cell biology and the medicines used to treat a wide range of human diseases but also in insects’ physiological functions. Recent studies have revealed the expression and function of GPCRs in insecticide resistance, improving our understanding of the molecular complexes governing the development of insecticide resistance. This article focuses on the review of G-protein coupled receptor (GPCR) signaling pathways in insect physiology, including insects’ reproduction, growth and development, stress responses, feeding, behaviors, and other physiological processes. Hormones and polypeptides that are involved in insect GPCR regulatory pathways are reviewed. The review also gives a brief introduction of GPCR pathways in organisms in general. At the end of the review, it provides the recent studies on the function of GPCRs in the development of insecticide resistance, focusing in particular on our current knowledge of the expression and function of GPCRs and their downstream regulation pathways and their roles in insecticide resistance and the regulation of resistance P450 gene expression. The latest insights into the exciting technological advances and new techniques for gene expression and functional characterization of the GPCRs in insects are provided.
Highlights
G-protein-coupled receptors (GPCRs) pathways, such as type C allatostatin peptide, which activates AST-C receptorGαi to protein and turn to activate β-arrestin2, and stimulate the activity of ERK [129]; activate human Gαi protein and turn to activate β-arrestin2, and stimulate the activity of adipokinetic hormone can bind with GPCR and activate Gα subunits to activate the ERK [129]; adipokinetic hormone can bind with GPCR and activate Gα subunits to glycogen phosphorylase and DAG [83,130]; and others can bind with GPCR to process activate the glycogen phosphorylase and DAG [83,130]; and others can bind with their physiological function through the cyclic adenosine monophosphate (cAMP) or Ca2+ channel activation [67,83,126,131,132,133,134,135]
A4 receptor gene amplified from cells taken from a B. mori brain and transfected into a human embryonic kidney cell line (HEK93) and an insect Spodoptera frugiperda cell line (Sf9) increased the cAMP concentration, calcium flux, extracellular signal-regulated kinase activity, receptor location, and ligand-binding efficiency, revealing a GPCR-regulation pathway led by neuropeptide F that involved several intracellular factors, including Gαi, adenylyl cyclase, and Ca2+ flux [143]
Scientists and researchers worldwide have been working diligently to elucidate the functions in cell biology, physiology, biochemistry, and molecular biology in both
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Many exceptional studies have revealed how GPCR genes and their potential biological functions can impact insect physiology [21,22], including reproduction [23,24,25,26,27,28], regulating growth and development [27,29,30,31,32,33,34,35,36,37,38,39], the stress response [40,41,42,43,44,45,46,47,48,49,50,51], feeding [27,32,52,53,54,55,56,57,58,59,60], behaviors [23,61,62,63,64,65,66], and other physiological processes [46,67,68,69,70,71,72,73,74]. The latest insights into the exciting technological advances and new techniques for gene expression and functional characterization of the GPCRs in insects are provided
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