Molecular cloning of ecdysone 20-hydroxylase and expression pattern of the enzyme during embryonic development of silkworm Bombyx mori
| Autor: | Noriyuki Hara, Yoichi Ito, Haruyuki Sonobe, Sayaka Maeda, Yoshinori Fujimoto, Asuka Nakashima, Ryouichi Yamada |
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| Rok vydání: | 2007 |
| Předmět: |
DNA
Complementary Magnetic Resonance Spectroscopy Physiology Molecular Sequence Data Embryonic Development Biology Molecular cloning Biochemistry Gene Expression Regulation Enzymologic Dephosphorylation chemistry.chemical_compound Bombyx mori Transcription (biology) Complementary DNA Animals Amino Acid Sequence RNA Messenger Cloning Molecular Molecular Biology Chromatography High Pressure Liquid Phylogeny chemistry.chemical_classification Ecdysteroid Base Sequence Sequence Homology Amino Acid fungi Gene Expression Regulation Developmental biology.organism_classification Bombyx Enzyme chemistry Steroid Hydroxylases Aryl Hydrocarbon Hydroxylases Baculoviridae Sequence Alignment Ecdysone |
| Zdroj: | Comparative biochemistry and physiology. Part B, Biochemistrymolecular biology. 149(3) |
| ISSN: | 1096-4959 |
| Popis: | In various insects, 20-hydroxyecdysone (20E) is indispensable for embryonic development. In eggs of the silkworm Bombyx mori, 20E has been demonstrated to be produced by two metabolic pathways: de novo synthesis from cholesterol and dephosphorylation of ovary-derived physiologically inactive ecdysteroid phosphates. In the former, ecdysone 20-hydroxylase (E20OHase) has been suggested to be a key enzyme. In the latter, it has been demonstrated that the dephosphorylation of ecdysteroid phosphates is catalyzed by a specific enzyme, ecdysteroid-phosphate phosphatase (EPPase). In this study, a cDNA encoding E20OHase was cloned from 3-day-old nondiapause eggs of B. mori and sequenced using PCR techniques. The protein exhibited the signature sequences characteristic of P450 enzymes, and mediated the conversion of ecdysone to 20E using the baculovirus expression system. Semi-quantitative analysis revealed that the E20OHase mRNA is expressed predominantly during gastrulation and organogenesis in nondiapause eggs, but is scarcely detected in diapause eggs whose development is arrested at the late gastrula stage. The developmental changes in the expression patterns of E20OHase and EPPase suggest that both enzyme activities are regulated at the transcription level, and both enzymes contribute cooperatively to 20E formation during embryonic development. |
| Databáze: | OpenAIRE |
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