Structural basis for the interaction of diapause hormone with its receptor in the silkworm, Bombyx mori

Abstract

Diapause hormone (DH) is a 24-aa amidated neuropeptide that elicits the embryonic diapause of the silkworm, Bombyx mori ( Bommo), via sensitive and selective interaction with its receptor, Bommo DH receptor ( Bommo-DHR). Previous studies of the structure-activity relationship of Bommo-DH were all based on an in vivo diapause-induction bioassay, which has provided little information on the structure of Bommo-DHR or its iteration with DH. Here, to unveil the interaction of Bommo-DH with its receptor, N-terminally truncated analogs and alanine-scanning mutants of Bommo-DH were chemically synthesized and functionally evaluated by using a Cy5.5-labeled Bommo-DH competitive binding assay and Bommo-DHR-based functional assays, including cAMP assay and Ca mobilization assay. Our study demonstrates that the C-terminal residues of Arg23 and Leu24 of Bommo-DH are essential for the binding and activation of Bommo-DHR, and that Trp19 and Phe20 also contribute to the functional activity of Bommo-DH. In contrast, when Gly21 or Pro22 were replaced with alanine, both mutants exhibited binding and signaling activities that were indistinguishable from the wild-type peptide. Furthermore, our homology modeling and molecular dynamics simulations, together with experimental validations, have identified the residues of Glu89, Phe172, Phe194, and Tyr299 in Bommo-DHR that are critically involved in the interaction with Bommo-DH. These results may deepen our understanding of the interactions of class-A GPCRs with their peptidic ligands, particularly those between pheromone biosynthesis-activating neuropeptide/DH family neuropeptides and their cognate receptors.-Shen, Z., Jiang, X., Yan, L., Chen, Y., Wang, W., Shi, Y., Shi, L., Liu, D., Zhou, N. Structural basis for the interaction of diapause hormone with its receptor in the silkworm, Bombyx mori.

The adipokinetic hormones and their cognate receptor from the desert locust, Schistocerca gregaria: solution structure of endogenous peptides and models of their binding to the receptor

“…As has been found before, insect neuropeptides are flexible in solution but generally have a preferred β-turn conformation (Mercurio et al, 2018; Shen et al, 2018; Zubrzycki, 2000). Using CD spectroscopy, Cusinato et al (1998) proposed a P II extended conformation for the AKH/RPCH peptides, at low temperatures, in aqueous solution.…”

G-Protein Coupled Receptors (GPCRs) in Insects—A Potential Target for New Insecticide Development

“…The majority are Class A GPCRs, including the dopamine receptor, which mainly regulates sexual activity [ 60 , 126 ], morphogenesis [ 29 , 34 , 35 , 97 ], mushroom and locomotor activity [ 127 ] and ethanol-induced sedation [ 68 ]. Neuropeptide and hormone receptors such as the adipokinetic hormone receptor (AKHR) can receive signals from the adipokinetic hormone and regulate lipid mobilization [ 51 , 53 , 62 , 106 ], while the allatostatin receptor (AstR) regulates the juvenile hormone synthesis [ 26 , 128 ], the diapause hormone receptor (DHR) is involved in insect development [ 39 , 41 , 45 ] and the neuropeptide receptors focus on the regulation of insect feeding behavior [ 50 , 129 ] and ecdysone synthesis [ 33 ]. Orphan receptor, like BNGR in B. mori regulates the insect’s food intake and growth [ 130 ], and DLGR2 in D. melanogaster regulates the insect’s bursicon bioactivity [ 25 ].…”

“…In just a few short years, GPCR research in insects has progressed from the initial GPCR gene identification to comprehensive bioinformatics analyses, from single GPCR gene analysis to whole genome sequences of GPCRs and explorations of their pathways, and from traditional transcriptional analysis of the gene expression to gene functional characterization of the GPCR genes in insect physiology and cellular biology. The incredible progress being made in related fields includes a wide range of complementary technologies, including bioinformatics and quantitative expression analyses, with functional studies using RNA interferon revealing potential biological functions that significantly impact insect physiology [ 17 , 18 ], including reproduction [ 19 , 20 , 21 , 22 , 23 , 24 ], regulating growth and development [ 21 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ], the stress response [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ], feeding [ 21 , 35 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ], general behaviors [ 20 , 57 ,…”

The Role of Peptide Hormones in Insect Lipid Metabolism

“…DH is produced by neurosecretory cells in the subesophageal ganglion and possesses three regions; the N-terminal region that facilitates binding of the hormone to the Diapause Hormone Receptor (DHR), the middle region with its duplicated amino acid structure for full potency, and the carboxy-terminal essential core structure for biological activity (Saito et al, 1994). The Arg 23 and Leu 24 in the carboxy-terminal core structure are essential for binding to the DHR, whereas Trp 19 and Phe 20 contribute to functional activity (Shen et al, 2018). Interestingly, the carboxy-terminal active peptide (24 amino acids) is homologous to the carboxy-terminus of Pheromone Biosynthesis Activating Neuropeptide (PBAN), which is involved in female sex pheromone biosynthesis; therefore, DH is encoded by a PBAN gene and has been named DH-PBAN (Sato et al, 1993; Table 1).…”