ダウンロード数: 302
このアイテムのファイル:
ファイル | 記述 | サイズ | フォーマット | |
---|---|---|---|---|
j.jinsphys.2016.09.012.pdf | 2 MB | Adobe PDF | 見る/開く |
タイトル: | Characterization of candidate intermediates in the Black Box of the ecdysone biosynthetic pathway in Drosophila melanogaster: Evaluation of molting activities on ecdysteroid-defective larvae |
著者: | Saito, Junki Kimura, Ryota Kaieda, Yuya Nishida, Ritsuo Ono, Hajime https://orcid.org/0000-0002-8042-2697 (unconfirmed) |
著者名の別形: | 小野, 肇 |
キーワード: | Ecdysteroidogenesis Ecdysone Black Box 7-Dehydrocholesterol Cholesta-4, 7-dien-3-one (3-oxo-Δ[4, 7]C) Drosophila melanogaster |
発行日: | 1-Oct-2016 |
出版者: | Elsevier Ltd |
誌名: | Journal of Insect Physiology |
巻: | 93-94 |
開始ページ: | 94 |
終了ページ: | 104 |
抄録: | Early steps of the biosynthetic pathway of the insect steroid hormone ecdysone remains the “Black Box” wherein the characteristic ecdysteroid skeleton is built. 7-Dehydrocholesterol (7dC) is the precursor of uncharacterized intermediates in the Black Box. The oxidation step at C-3 has been hypothesized during conversion from 7dC to 3-oxo-2, 22, 25-trideoxyecdysone, yet 3-dehydroecdysone is undetectable in some insect species. Therefore, we first confirmed that the oxidation at C-3 occurs in the fruitfly, Drosophila melanogaster using deuterium-labeled cholesterol. We next investigated the molting activities of candidate intermediates, including oxidative products of 7dC, by feeding-rescue experiments for Drosophila larvae in which an expression level of a biosynthetic enzyme was knocked down by the RNAi technique. We found that the administration of cholesta-4, 7-dien-3-one (3-oxo-Δ4, 7C) could overcome the molting arrest of ecdysteroid-defective larvae in which the expression level of neverland was reduced. However, feeding 3-oxo-Δ4, 7C to larvae in which the expression levels of shroud and Cyp6t3 were reduced inhibited molting at the first instar stage, suggesting that this steroid could be converted into an ecdysteroid-antagonist in loss of function studies of these biosynthetic enzymes. Administration of the highly conjugated cholesta-4, 6, 8(14)-trien-3-one, oxidized from 3-oxo-Δ4, 7C, did not trigger molting of ecdysteroid-defective larvae. These results suggest that an oxidative product derived from 7dC is converted into ecdysteroids without the formation of this stable conjugated compound. We further found that the 14α-hydroxyl moiety of Δ4-steroids is required to overcome the molting arrest of larvae in loss of function studies of Neverland, Shroud, CYP6T3 or Spookier, suggesting that oxidation at C-14 is indispensable for conversion of these Δ4-steroids into ecdysteroids via 5β-reduction. |
著作権等: | © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ The full-text file will be made open to the public on 01 October 2017 in accordance with publisher's 'Terms and Conditions for Self-Archiving'. This is not the published version. Please cite only the published version. この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。 |
URI: | http://hdl.handle.net/2433/231026 |
DOI(出版社版): | 10.1016/j.jinsphys.2016.09.012 |
PubMed ID: | 27662806 |
出現コレクション: | 学術雑誌掲載論文等 |
このリポジトリに保管されているアイテムはすべて著作権により保護されています。