RNA METABOLISM IN HELA CELL NUCLEUS
RNA METABOLISM IN HELA CELL NUCLEUS
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DOI：
10.1016/s0022-2836(66)80098-0
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发表时间：
1966-01-01
影响因子：
5.6
通讯作者：
PENMAN, S
中科院分区：
文献类型：
--
作者：
PENMAN, S
描述了一种从HeLa细胞制备核级分的方法。该馏分不含核糖体的16 s RNA组分的可观的量，因此似乎是免费的细胞质污染。细胞质核糖体RNA的所有早期前体都包含在核组分中。从核级分提取的RNA的沉降分析显示在45秒处的光密度峰和在约30秒处沉降的更大的峰。30 s区域的RNA是多分散的，含有35 s和28 s RNA。先前的工作表明，核糖体RNA形成的初始事件是45 s RNA的合成。图中显示，下一步是45 s RNA裂解形成16 s RNA，后者立即出现在细胞质中，35 s RNA留在细胞核中。35 s RNA经过一个过渡到28 s，然后进入细胞质。放线菌素存在时45 s RNA裂解为35 s和16 s RNA，但35 s RNA随后的行为异常。追踪放射性标记的实验表明，没有高分子量RNA与细胞核永久结合。
A method of preparing a nuclear fraction from HeLa cells is described. The fraction does not contain an appreciable amount of the 16 s RNA component of ribosomes and thus appears to be free of cytoplasmic contamination. All of the early precursors to cytoplasmic ribosomal RNA are contained in the nuclear fraction. Sedimentation analysis of the RNA extracted from the nuclear fraction shows a peak in optical density at 45 s and a larger peak that sediments about 30 s. The RNA in the 30 s region is shown to be polydisperse and contains 35 s and 28 s RNA. Previous work has shown that the initial event in the formation of ribosomal RNA is the synthesis of 45 s RNA. It is shown here that the next step is the cleavage of 45 s RNA to form 16 s RNA, which emerges immediately into the cytoplasm, and 35 s RNA which remains in the nucleus. The 35 s RNA undergoes a transition to 28 s and then enters in the cytoplasm. The cleavage of 45 s to 35 s and 16 s RNA proceeds in the presence of actinomycin but the subsequent behavior of the 35 s RNA is abnormal. Experiments in which radioactive label is chased shows that there is no high molecular weight RNA permanently associated with the nucleus.