Identification of a novel prothoracicostatic hormone and its receptor in the silkworm Bombyx mori.
The insect brain regulates the activity of the prothoracic glands to secrete ecdysteroids, which affect growth, molting, and metamorphosis. Here we report the identification of a novel prothoracicostatic factor and its receptor in the silkworm Bombyx mori. The prothoracicostatic factor purified from pupal brains of B. mori is a decapeptide with the conserved structure of an insect myosuppressin and thus named Bommo-myosuppressin. Bommo-myosuppressin dose dependently suppressed the cAMP level and inhibited ecdysteroidogenesis in the larval prothoracic glands at much lower concentrations than the prothoracicostatic peptide, the other prothoracicostatic factor reported previously. In vitro analyses using a prothoracic gland incubation method revealed that Bommo-myosuppressin and prothoracicostatic peptide regulate the prothoracic gland activity via different receptors. In situ hybridization and immunohistochemistry revealed the existence of Bommo-myosuppressin in the brain neurosecretory cells projecting to neurohemal organs in which it is stored. We also identified and functionally characterized a specific receptor for Bommo-myosuppressin and showed its high expression in the prothoracic glands. All these results suggest that Bommo-myosuppressin functions as a prothoracicostatic hormone and plays an important role in controlling insect development.
Yamanaka
Naoki
N
Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan.
Hua
Yue-Jin
YJ
Mizoguchi
Akira
A
Watanabe
Ken
K
Niwa
Ryusuke
R
Tanaka
Yoshiaki
Y
Kataoka
Hiroshi
H
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D012831:Bombyx; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D000242:Cyclic AMP / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D019992:Databases as Topic; D004440:Ecdysone / Q000737:chemistry; D020224:Expressed Sequence Tags; D015723:Gene Library; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007301:Insect Hormones / Q000096:biosynthesis* / Q000737:chemistry*; D008024:Ligands; D013058:Mass Spectrometry; D008675:Metamorphosis, Biological; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry* / Q000502:physiology*; D010455:Peptides / Q000737:chemistry; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013053:Spectrophotometry; D014466:Ultraviolet Rays
D018076:DNA, Complementary; D007301:Insect Hormones; D008024:Ligands; D009479:Neuropeptides; D010455:Peptides; C400522:alanyl-tryptophyl-glutaminyl-aspartyl-leucyl-asparagyl-seryl-alanyl-tryptophanamide; D004440:Ecdysone; D000242:Cyclic AMP; D002118:Calcium