Felicetti L, Urbani C
Biochim Biophys Acta. 1977 Feb 16;474(4):595-608. doi: 10.1016/0005-2787(77)90079-x.
Actinomycin D inhibits hemoglobin synthesis in rabbit reticulocyte lysates by affecting initiation of globin polypeptide chains. To obtain information on the distribution of actinomycin-sensitive structures among the components of the translation machinery, a reticulocyte lysate is incubated with [3H]actinomycin. The tritium label is found associated with ribosomes actively engaged in protein synthesis and with a 15 S cytoplasmic particle. During cell-free incubation or when initiation is inhibited by aurintricarboxylic acid, the labeling of the 15 S particles increases, suggesting that they are relased from ribosomes into the cytoplasm and play a role in the initiation process. The 15 S cytoplasmic particles contain a DNAase-sensitive component, probably complexed with ribonucleic acids and proteins. A possible role of these DNA-containing particles in the initiation step of translation is discussed.
放线菌素D通过影响珠蛋白多肽链的起始过程来抑制兔网织红细胞裂解物中的血红蛋白合成。为了获取有关放线菌素敏感结构在翻译机制各组分中的分布信息，将网织红细胞裂解物与[³H]放线菌素一起孵育。发现氚标记与积极参与蛋白质合成的核糖体以及一种15S细胞质颗粒相关联。在无细胞孵育期间或当起始过程被金精三羧酸抑制时，15S颗粒的标记增加，这表明它们从核糖体释放到细胞质中并在起始过程中发挥作用。15S细胞质颗粒含有一种对DNA酶敏感的成分，可能与核糖核酸和蛋白质复合。讨论了这些含DNA颗粒在翻译起始步骤中可能的作用。
