Kim, Mi Ae Kim, Tae Ha Kannan, Priyadharshini Kho, Kang Hee Park, Keunwan Sohn, Young Chang 2024-01-19T08:33:17Z 2024-01-19T08:33:17Z 2023-10-29 2024-01 0028-3835 https://pubs.kist.re.kr/handle/201004/113266 Introduction: The proposed evolutionary origins and corresponding nomenclature of bilaterian gonadotropin-releasing hormone (GnRH)-related neuropeptides have changed tremendously with the aid of receptor deorphanization. However, the reclassification of the GnRH and corazonin (CRZ) signaling systems in Lophotrochozoa remains unclear.Methods: We characterized GnRH and CRZ receptors in the mollusk Pacific abalone, Haliotis discus hannai (Hdh), by phylogenetic and gene expression analyses, bioluminescence-based reporter, western blotting, substitution of peptide amino acids, in vivo neuropeptide injection, and RNA interference assays.Results: Two Hdh CRZ-like receptors (Hdh-CRZR-A and Hdh-CRZR-B) and three Hdh GnRH-like receptors (Hdh-GnRHR1-A, Hdh-GnRHR1-B, and Hdh-GnRHR2) were identified. In phylogenetic analysis, Hdh-CRZR-A and -B grouped within the CRZ-type receptors, whereas Hdh-GnRHR1-A/-B and Hdh-GnRHR2 clustered within the GnRH/adipokinetic hormone (AKH)/CRZ-related peptide-type receptors. Hdh-CRZR-A/-B and Hdh-GnRHR1-A were activated by Hdh-CRZ (pQNYHFSNGWHA-NH2) and Hdh-GnRH (pQISFSPNWGT-NH2), respectively. Hdh-CRZR-A/-B dually coupled with the G alpha(q) and G alpha(s) signaling pathways, whereas Hdh-GnRHR1-A was linked only with G alpha(q) signaling. Analysis of substituted peptides, [(IS3)-S-2]Hdh-CRZ and [(NYH4)-Y-2-H-3]Hdh-GnRH, and in silico docking models revealed that the N-terminal amino acids of the peptides are critical for the selectivity of Hdh-CRZR and Hdh-GnRHR. Two precursor transcripts for Hdh-CRZ and Hdh-GnRH peptides and their receptors were mainly expressed in the neural ganglia, and their levels increased in starved abalones. Injection of Hdh-CRZ peptide into abalones decreased food consumption, whereas Hdh-CRZR knockdown increased food consumption. Moreover, Hdh-CRZ induced germinal vesicle breakdown in mature oocytes.Conclusion: Characterization of Hdh-CRZRs and Hdh-GnRHRs and their cognate peptides provides new insight into the evolutionary route of GnRH-related signaling systems in bilaterians. English S. Karger AG Functional Characterization of Gonadotropin-Releasing Hormone and Corazonin Signaling Systems in Pacific Abalone: Toward Reclassification of Invertebrate Neuropeptides Article 10.1159/000533662 1 Neuroendocrinology, v.114, no.1, pp.64 - 89 Neuroendocrinology 114 1 64 89 N scie scopus 001077493400001 Endocrinology & Metabolism Neurosciences Endocrinology & Metabolism Neurosciences & Neurology Article CENTRAL-NERVOUS-SYSTEM INTRACELLULAR LOOP MOLECULAR-CLONING GNRH-RECEPTORS EXPRESSION PEPTIDES TRANSDUCTION EVOLUTION MOLLUSK ENERGY Pacific abalone GnRH corazonin reclassification food consumption