La vitellogénine chez un Crustacé Décapode Natantia, Palaemon serratus Pennant. Mise en évidence, comparaison immunologique avec les vitellines, site de synthèse et rôle des pédoncules oculaires

International audienc

Characterization and hormonal regulation of tissue and fluid proteins in the mouse epididymis

International audienc

Characterization of regional proteins in tissues and fluids in the human epididymis

International audienc

Identification and characterization of vitellin in a hermaphrodite shrimp, Pandalus kessleri

1. A female specific protein (FSP, vitellogenin) in hemolymph and its related ovarian protein (vitellin) of Pandalus kessleri were studied by means of electrophoretical and immunological procedures. 2. The vitellin was purified from vitellogenic ovaries using hydroxylapatite, DEAE cellulose and Sepharose 6B columns, consecutively. 3. The vitellin had a molecular weight of approximately 560 kD and was composed of two subunits, 81 and 110 kD, respectively. 4. The vitellogenin concentrations in the hemolymph increased as vitellogenesis in the ovarian oocytes advanced and dropped markedly after the release of mature eggs

Quelques aspects du contrôle hormonal de la synthèse de la vitellogénine chez le crustacé amphipode Orchestia gammarella (Pallas)

International audienc

Phosphorylation of UBF at serine 388 is required for interaction with RNA polymerase I and activation of rDNA transcription

Modulation of the activity of the upstream binding factor (UBF) plays a key role in cell cycle-dependent regulation of rRNA synthesis. Activation of rDNA transcription on serum stimulation requires phosphorylation of UBF at serine 484 by G(1)-specific cyclin-dependent kinase (cdk)/cyclin complexes. After G(1) progression UBF is phosphorylated at serine 388 by cdk2/cyclin E and cdk2/cyclin A. Conversion of serine 388 to glycine abolishes UBF activity, whereas substitution by aspartate enhances the transactivating function of UBF. Protein–protein interaction studies reveal that phosphorylation at serine 388 is required for the interaction between RNA polymerase I and UBF. The results suggest that phosphorylation of UBF represents a powerful means of modulating the assembly of the transcription initiation complex in a proliferation- and cell cycle-dependent fashion