Leader D P, Thomas A, Voorma H O
Biochim Biophys Acta. 1981 Nov 27;656(1):69-75. doi: 10.1016/0005-2787(81)90028-9.
We describe a re-examination of the cell-free protein synthetic activity of eukaryotic ribosomes having proteins phosphorylated to different extents. Ribosomal 40 S subunits were isolated both from a variety of cells in which there is relatively little phosphorylation of ribosomal protein S6, and from cells subjected in vivo to different stimuli that promote the extensive phosphorylation of protein S6. The ability of these subunits to bind Met-tRNA as well as the second amino acyl-tRNA (Val-tRNA) was compared in the presence of highly purified initiation factors, elongation factor EF-1 at various concentrations of 60S subunits, 9 S globin mRNA and potassium ions. The ability of the subunits to synthesize polyphenylalanine was also studied using highly purified elongation factors. In no case was any significant difference in activity observed between ribosomes with protein S6 phosphorylated to different extents. Similar, though less extensive, studies were preformed comparing 60 S ribosomal subunits differing in the extent of phosphorylation of the acidic phosphoprotein, L gamma , and of L14. No difference in activity was observed between these ribosomes.
我们描述了对蛋白质磷酸化程度不同的真核核糖体无细胞蛋白质合成活性的重新研究。核糖体40S亚基既从核糖体蛋白S6磷酸化程度相对较低的多种细胞中分离得到，也从体内受到促进蛋白S6广泛磷酸化的不同刺激的细胞中分离得到。在存在高度纯化的起始因子、不同浓度的60S亚基、9S珠蛋白mRNA和钾离子的情况下，比较了这些亚基结合甲硫氨酰 - tRNA以及第二个氨酰 - tRNA（缬氨酰 - tRNA）的能力。还使用高度纯化的延伸因子研究了这些亚基合成聚苯丙氨酸的能力。在任何情况下，蛋白质S6磷酸化程度不同的核糖体之间均未观察到活性有任何显著差异。对酸性磷蛋白Lγ和L14磷酸化程度不同的60S核糖体亚基进行了类似但规模较小的研究。这些核糖体之间未观察到活性差异。
