title: Suppression of the ecdysteroid-triggered growth arrest by a novel Drosophila membrane steroid binding protein.
abstract: Ecdysteroid is a crucial steroid hormone in insects, especially during metamorphosis. Here, we show that the Drosophila membrane steroid binding protein (Dm_MSBP) is a novel structural homolog of the vertebrate membrane-bound receptor component for progesterone. Dm_MSBP exhibited binding affinity to ecdysone when expressed on the cell surface of Drosophila S2 cells. In S2 cells, the stable overexpression of Dm_MSBP suppressed the growth arrest triggered by 20-hydroxyecdysone and prevented the temporal activation of extracellular signal-regulated kinase proteins. These results suggest that Dm_MSBP is a membranous suppressor to ecdysteroid and blocks the signaling by binding it in extracellular fluid.
authors.affiliation: Faculty of Pharmaceutical Sciences, Teikyo University, Sagamihara, Kanagawa 229-0195, Japan.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Fujii-Taira
authors.forename: Shinji
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Ryoko
authors.initials: R
authors.lastname: Iijima
authors.forename: Shunji
authors.initials: S
authors.lastname: Natori
authors.forename: Koichi J
authors.initials: KJ
authors.lastname: Homma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004330:Drosophila / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D026461:Ecdysteroids / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008675:Metamorphosis, Biological; D008969:Molecular Sequence Data; D010802:Phylogeny; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D029721:Drosophila Proteins; D026461:Ecdysteroids; C539160:MSBP protein, Drosophila; D008565:Membrane Proteins