title: Neuropeptide receptor transcriptome reveals unidentified neuroendocrine pathways.
abstract: Neuropeptides are an important class of molecules involved in diverse aspects of metazoan development and homeostasis. Insects are ideal model systems to investigate neuropeptide functions, and the major focus of insect neuropeptide research in the last decade has been on the identification of their receptors. Despite these vigorous efforts, receptors for some key neuropeptides in insect development such as prothoracicotropic hormone, eclosion hormone and allatotropin (AT), remain undefined. In this paper, we report the comprehensive cloning of neuropeptide G protein-coupled receptors from the silkworm, Bombyx mori, and systematic analyses of their expression. Based on the expression patterns of orphan receptors, we identified the long-sought receptor for AT, which is thought to stimulate juvenile hormone biosynthesis in the corpora allata (CA). Surprisingly, however, the AT receptor was not highly expressed in the CA, but instead was predominantly transcribed in the corpora cardiaca (CC), an organ adjacent to the CA. Indeed, by using a reverse-physiological approach, we purified and characterized novel allatoregulatory peptides produced in AT receptor-expressing CC cells, which may indirectly mediate AT activity on the CA. All of the above findings confirm the effectiveness of a systematic analysis of the receptor transcriptome, not only in characterizing orphan receptors, but also in identifying novel players and hidden mechanisms in important biological processes. This work illustrates how using a combinatorial approach employing bioinformatic, molecular, biochemical and physiological methods can help solve recalcitrant problems in neuropeptide research.
authors: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
authors: Naoki
authors: N
authors: Yamanaka
authors: Sachie
authors: S
authors: Yamamoto
authors: Dusan
authors: D
authors: Zitnan
authors: Ken
authors: K
authors: Watanabe
authors: Tsuyoshi
authors: T
authors: Kawada
authors: Honoo
authors: H
authors: Satake
authors: Yu
authors: Y
authors: Kaneko
authors: Kiyoshi
authors: K
authors: Hiruma
authors: Yoshiaki
authors: Y
authors: Tanaka
authors: Tetsuro
authors: T
authors: Shinoda
authors: Hiroshi
authors: H
authors: Kataoka
mesh_terms: D000818:Animals; D012831:Bombyx / Q000254:growth & development / Q000502:physiology; D004330:Drosophila / Q000235:genetics / Q000502:physiology; D015870:Gene Expression; D020869:Gene Expression Profiling; D007814:Larva / Q000502:physiology; D008024:Ligands; D009479:Neuropeptides / Q000502:physiology; D009490:Neurosecretory Systems / Q000502:physiology*; D018013:Receptors, Neuropeptide / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D008024:Ligands; D009479:Neuropeptides; D018013:Receptors, Neuropeptide