title: Cell-free synthesis of rat liver zinc-thioneins.
abstract: The induction of rat liver zinc-thioneins mRNA was studied in a wheat germ cell-free translation system. Liver poly A rich polysomal RNA was isolated from rats which had been injected with zinc sulfate 5 h previously. These RNA preparations stimulated the incorporation of [35S]cystine into trichloroacetic acid insoluble proteins when assayed in the cell-free synthetic system. The translation products were characterized by Sephadex G-75 chromatography in 8 M urea--50 mM beta-mercaptoethanol, by disc gel electrophoresis in 4 M area--Tris-glycine buffer (pH 9.2), and by peptide fingerprinting with pepsin. These results were identical with authentic rat liver zinc-thioneins. The zinc-thioneins mRNA activity in the control rats, however, was minimal. The stimulation in zinc-thioneins synthesis observed in the cell-free synthesis was similar to the increased synthesis of these polypeptides in vivo.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002474:Cell-Free System; D008099:Liver / Q000378:metabolism*; D008297:Male; D008667:Metalloproteins / Q000096:biosynthesis*; D008668:Metallothionein / Q000096:biosynthesis*; D010944:Plants / Q000378:metabolism; D011061:Poly A / Q000378:metabolism; D014176:Protein Biosynthesis; D012335:RNA, Ribosomal / Q000378:metabolism; D051381:Rats; D014908:Triticum / Q000378:metabolism; D015032:Zinc / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D008667:Metalloproteins; D012335:RNA, Ribosomal; D011061:Poly A; D008668:Metallothionein; D015032:Zinc