METABOLISM OF POLYADENYLATE SEQUENCE OF NUCLEAR-RNA AND MESSENGER-RNA IN MAMMALIAN-CELLS
METABOLISM OF POLYADENYLATE SEQUENCE OF NUCLEAR-RNA AND MESSENGER-RNA IN MAMMALIAN-CELLS
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DOI：
10.1016/0092-8674(75)90102-6
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发表时间：
1975-01-01
期刊：
影响因子：
64.5
通讯作者：
DIEZ, J
中科院分区：
文献类型：
--
作者：
BRAWERMAN, G;DIEZ, J
小鼠肉瘤和中国仓鼠细胞的mRNA和核RNA分子3‘端的聚(A)序列经历了一个不同于从头合成的伸长过程。这一过程在用高水平放线菌素D抑制转录的细胞中继续进行。这导致细胞质中稳定状态的聚(A)群体和细胞核中异常长的聚(A)片段的标记。在未加药物处理的细胞与~3H-腺苷孵育的细胞中，3‘端带有短标记序列的细胞质稳态多聚(A)片段可以通过其不均匀的大小分布和碱水解释放的腺苷和AMP的测量来检测。这些测量表明标记序列的平均大小为8个残基。在细胞核中，通过测量AMP和腺苷，也可以检测到先前存在的聚(A)链的缓慢延长。细胞质的延长过程导致mRNA上聚(A)序列3‘端的翻转，因为伴随着AMP残基的去除。它显然与信使核糖核酸的翻译无关。中国仓鼠和小鼠肉瘤细胞在聚(A)链延伸和从头合成的相对程度上似乎明显不同。
The poly (A) sequences at the 3’end of mRNA and nuclear RNA molecules of mouse sarcoma and Chinese hamster cells are subject to an elongation process distinct from de novo synthesis. This process continues in cells treated with a high level of actinomycin D to block transcription. This results in the labeling of the steady-state poly (A) population in the cytoplasm and of unusually long poly (A) segments in the nucleus. In cells incubated with 3H-adenosine in the absence of drug treatment, cytoplasmic steady-state poly (A) segments with short labeled sequences at the 3’end can be detected by their heterogeneous size distribution and by measurements of adenosine and AMP released by alkaline hydrolysis. These measurements indicate an average size of 8 residues for the labeled sequences. In the nucleus, a slow elongation of preexisting poly (A) chains can also be detected through measurements of AMP and adenosine. The cytoplasmic elongation process leads to turnover of the 3’end of the poly (A) sequence on mRNA, because of concomitant removal of AMP residues. It is apparently not linked to mRNA translation. The Chinese hamster and mouse sarcoma cells appear to differ markedly with respect to relative extents of poly (A) chain extension and de novo synthesis.