Administration of estradiol 17β to male Xenopus laevis induces synthesis and secretion by the liver of the egg yolk precursor protein vitellogenin. RNA extracted from livers of estradiol 17β treated Xenopus laevis directs the synthesis of the entire 200,000 dalton vitellogenin monomer in a cell free protein synthesizing system derived from rabbit reticulocytes. Vitellogenin synthesized in vitro was isolated and quantitated by indirect immunoprecipitation and identified by comparison to authentic [14C]vitellogenin. The in vitro product and [14C]vitellogenin co migrate on electrophoresis in sodium dodecyl sulfate polyacrylamide gels and they exhibit identical immunoprecipitation curves. Xenopus laevis vitellogenin messenger RNA has a sedimentation coefficient of approximately 30 S in sucrose density gradients. It can be purified approximately 60 fold from cell RNA by poly(U) Sepharose chromatography and therefore appears to contain a polyadenylate sequence. Vitellogenin mRNA and vitellogenin synthesis in vivo could not be detected in unstimulated male Xenopus laevis. The relative rate of vitellogenin synthesis and the level of vitellogenin mRNA were determined at various times following the administration of estradiol 17β. Vitellogenin synthesis is maximal 12 days after estradiol 17β administration when it comprises approximately 70% of cell protein synthesis. The level of vitellogenin mRNA and the intracellular rate of vitellogenin synthesis exhibit a close correspondence from 4 to 16 days after administration of estradiol 17β.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Biological Chemistry|
|State||Published - 1976|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology