title: Ecdysone-regulation of synthesis and processing of fat body protein 1, the larval serum protein receptor of Drosophila melanogaster.
abstract: At the end of the third larval instar of Drosophila melanogaster, larval serum proteins 1 and 2 (LSP-1 and -2) are taken up by cells of the fat body. Here, we show that the product of the ecdysteroid-inducible gene Fbp-1 (Fat Body Protein 1) is the receptor that binds LSP-1. Transcription and translation of Fbp-1 is stage-specifically restricted to the end of the third larval instar, starting around 99 h after egg laying. Expression of Fbp-1 is induced by a low level of 20-hydroxy-ecdysone (>/= 10-7 m). After translation, the FBP-1 protein is thought to be proteolytically cleaved in three subsequent steps. The final cleavage step is delayed by 6 h and relies on a higher concentration of ecdysone (>/= 10-5 m). Therefore, 20-hydroxy-ecdysone regulates Fbp-1 expression and function at two different levels. To the best of our knowledge, this study is the first to date to demonstrate two distinct functions for different concentrations of a steroid hormone on a single biochemical process.
authors.affiliation: Institut Jacques-Monod, Biologie du Développement, CNRS et Université Paris 6 et Paris 7, France.
authors.forename: T
authors.initials: T
authors.lastname: Burmester
authors.forename: C
authors.initials: C
authors.lastname: Antoniewski
authors.forename: J A
authors.initials: JA
authors.lastname: Lepesant
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000378:metabolism*; D004440:Ecdysone / Q000494:pharmacology*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D006868:Hydrolysis; D019476:Insect Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000378:metabolism*; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational / Q000187:drug effects*
chemical_list: D017931:DNA Primers; D029721:Drosophila Proteins; C087777:Fbp1protein, Drosophila; D019476:Insect Proteins; D004440:Ecdysone