SCANNING INDEPENDENT RIBOSOMAL INITIATION OF THE SENDAI VIRUS-Y PROTEINS INVITRO AND INVIVO
SCANNING INDEPENDENT RIBOSOMAL INITIATION OF THE SENDAI VIRUS-Y PROTEINS INVITRO AND INVIVO
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DOI：
10.1002/j.1460-2075.1989.tb03406.x
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发表时间：
1989-02-01
期刊：
影响因子：
11.4
通讯作者：
KOLAKOFSKY, D
中科院分区：
文献类型：
--
作者：
CURRAN, J;KOLAKOFSKY, D
仙台病毒P/C mRNA在从5“端起的位置81和201之间含有5个核糖体起始位点。这些位点中的一个起始于P开放阅读框（ORF）（ATG/104），而四个起始于C ORF（ACG/81和ATG/114、183、201），以产生一组嵌套的C蛋白（C“、C、Y1、Y2）。在体外引入新的ATG或物理破坏这些天然位点上游的mRNA以防止核糖体扫描下游。结果表明，少数启动C的核糖体（ATG/114）和所有启动Y1和Y2的核糖体（ATG/183和201）都是通过扫描独立机制完成的。当在体内实验中将泄漏的ACG/81位点改变为非泄漏的ATG位点时，Y处的核糖体起始再次不减少，而C处以及P处的核糖体起始变得不可检测。在Y的核糖体起始似乎在体外和体内是扫描独立的。在体外，C是部分独立的，但在体内完全依赖。这些结果进行了讨论，在Y的内部引发的模型。
The Sendai virus P/C mRNA contains five ribosomal initiation sites between positions 81 and 201 from the 5'' end. One of these sites initiates in the P open reading frame (ORF) (ATG/104), whereas four initiate in the C ORF (ACG/81 and ATGs/114, 183, 201), to give a nested set of C proteins (C'', C, Y1, Y2). Introduction of new ATGs or physically breaking the mRNA upstream of these natural sites was used in vitro to prevent ribosomal scanning downstream. The results suggest that a minority of the ribosomes which initiate C (ATG/114) and all of those which initiate Y1 and Y2 (ATGs/183 and 201) do so by a scanning independent mechanism. When the leaky ACG/81 site is changed to a non-leaky ATG site in in vivo experiments, ribosomal initiation at Y is again not diminished, whereas that at C as well as at P becomes undetectable. Ribosomal initiation at Y appears to be scanning independent in vitro and in vivo. That at C is partly independent in vitro, but completely dependent in vivo. These results are discussed in terms of a model of internal initiation at Y.