title: Glucose dependent [correction of dependant] negative translational control of the heterologous expression of the preS2 HBV antigen in yeast.
abstract: In the present study, we have compared the expression level of the genes encoding the viral Hepatitis B S and preS2 using two different yeast vectors, a constitutive one (YepIPT) and a galactose-inducible one (YepDP1-8). We showed that the S and preS2 mRNAs were present in equivalent amounts in both systems, while the corresponding proteins showed a different pattern. The S and preS2 proteins were efficiently produced after galactose induction. However, under the constitutive promoter, the S protein was synthesized at the same level in presence of 2% glucose or galactose whereas the preS2 protein was efficiently synthesized on galactose but absent on 2% glucose. The substitution of glucose by non-repressive carbon sources such as 2% galactose, ethanol or glycerol led to a significant expression of preS2. A high level of preS2 expression was also achieved by lowering the glucose concentration. Our data suggest that glucose exerts a concentration dependent negative translational control on the preS2 mRNA.
authors.affiliation: Laboratoire de Génétique Moléculaire des Eucaryotes, Centre de Biotechnologie de Sfax, BP K 3038, Sfax, Tunisia.
authors.forename: Istabrak
authors.initials: I
authors.lastname: Borchani-Chabchoub
authors.forename: Raja
authors.initials: R
authors.lastname: Mokdad-Gargouri
authors.forename: Ali
authors.initials: A
authors.lastname: Gargouri
mesh_terms: D015152:Blotting, Northern; D015153:Blotting, Western; D005656:Fungal Proteins / Q000235:genetics; D005690:Galactose / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D005822:Genetic Vectors / Q000235:genetics; D005947:Glucose / Q000494:pharmacology*; D006514:Hepatitis B Surface Antigens / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics*; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*
chemical_list: D005656:Fungal Proteins; D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C050807:presurface protein 2, hepatitis B surface antigen; D005947:Glucose; D005690:Galactose