Shiokawa K
Cell Struct Funct. 1984 Mar;9(1):97-102. doi: 10.1247/csf.9.97.
A fraction containing acid-soluble materials (PCA-extract) from Xenopus early blastulae preferentially inhibits the incorporation of [3H]uridine into 18S and 28S rRNA in Xenopus neurula cells. Pulse- laneling experiments revealed that whereas tubercidin, a known inhibitor of rRNA processing, produced a marked accumulation of the label in 40S pre-rRNA, Xenopus inhibitor suppressed labeling of the pre-rRNA. When tubercidin was added to cells whose activity for rRNA synthesis had been lowered by the Xenopus inhibitor, there was still an accumulation of label in the pre-rRNA. These results indicate that Xenopus inhibitor suppresses the synthesis of rRNA at transcription rather than at processing.
一种含有非洲爪蟾早期囊胚酸溶性物质（PCA提取物）的组分优先抑制[3H]尿苷掺入非洲爪蟾神经胚细胞的18S和28S rRNA中。脉冲标记实验表明，虽然已知的rRNA加工抑制剂杀结核菌素会使40S前体rRNA中的标记显著积累，但非洲爪蟾抑制剂却抑制了前体rRNA的标记。当将杀结核菌素添加到rRNA合成活性因非洲爪蟾抑制剂而降低的细胞中时，前体rRNA中仍有标记积累。这些结果表明，非洲爪蟾抑制剂在转录而非加工阶段抑制rRNA的合成。
