The HTLV-1 Rex protein induces nuclear accumulation of unspliced viral RNA by avoiding intron excision and degradation
The HTLV-1 Rex protein induces nuclear accumulation of unspliced viral RNA by avoiding intron excision and degradation
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DOI：
10.1006/viro.1996.0200
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发表时间：
1996-04-15
期刊：
影响因子：
3.7
通讯作者：
Grassmann, R
中科院分区：
文献类型：
--
作者：
Grone, M;Koch, C;Grassmann, R
人t细胞白血病病毒（HTLV-1）的Rex蛋白在细胞质中积累不完全剪接转录本是必不可少的，这些转录本编码病毒结构蛋白。本研究测定了Rex对HTLV-1总RNA、剪接RNA和未剪接RNA数量的影响。在转染的成纤维细胞中，Rex的产生导致细胞核中剪接RNA的数量减少和未剪接RNA的数量增加。然而，病毒RNA的总量没有受到影响，剪接转录物的稳定性也没有改变，这表明剪接速率只是降低了。雷克斯作用也减少了永生人类脐带血t细胞的剪接。然而，在这些细胞中，Rex的存在也增加了病毒转录物的总量和未剪接RNA的稳定性。这表明Rex也能阻止t细胞中未剪接转录物的降解。Rex诱导的剪接和未剪接RNA的相对数量的变化不仅在细胞质中观察到，而且在细胞核中也观察到。因此，Rex影响核内HTLV-I RNA的核胞质转运、剪接和稳定性。这些观察结果可能表明，Rex将未剪接的病毒RNA通过剪接和降解因子无法进入的核室引导到细胞质中。(C) 1996年学术出版社。公司。
The human T-cell leukemia virus (HTLV-1) Rex protein is essential for the cytoplasmic accumulation of incompletely spliced transcripts that code for the viral structural proteins. in this study effects of Rex on the amounts of total, spliced, and unspliced RNA from HTLV-1 were determined. In transfected fibroblasts Rex production resulted in reduced amounts of spliced RNA and increased quantities of unspliced RNA in the nucleus. However, the total amount of viral RNA was not affected and the stability of spliced transcripts was not changed, thus indicating that only the rate of splicing was reduced. Rex action also reduced splicing in immortalized human cord blood T-cells. However, the total amount of viral transcripts and the stability of unspliced RNA in these cells were also increased in the presence of Rex. This indicates that Rex also prevents the degradation of unspliced transcripts in T-cells. The changes in the relative amounts of spliced and unspliced RNA induced by Rex were observed not only in the cytoplasm but also in the nucleus. Thus Rex affects the nucleocytoplasmic transport, splicing, and stability of HTLV-I RNA in the nucleus. These observations may suggest that Rex directs the unspliced viral RNA to the cytoplasm via a nuclear compartment that is not accessible to splicing and degradation factors. (C) 1996 Academic Press. Inc.