TAP, the human homolog of Mex67p, mediates CTE-dependent RNA export from the nucleus
TAP, the human homolog of Mex67p, mediates CTE-dependent RNA export from the nucleus
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DOI：
10.1016/s1097-2765(00)80065-9
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发表时间：
1998-04-01
期刊：
影响因子：
16
通讯作者：
Izaurralde, E
中科院分区：
文献类型：
--
作者：
Gruter, P;Tabernero, C;Izaurralde, E
D型逆转录病毒的组成型转运元件（CTE）明显地通过募集细胞信使RNA输出所需的宿主因子来促进未剪接的病毒RNA的核输出。在这里，我们报告的鉴定TAP的细胞因子，特异性结合野生型CTE，但不出口缺陷CTE突变体。在非洲爪蟾卵母细胞中进行的显微注射实验表明，TAP直接刺激CTE依赖的出口。此外，TAP克服了由饱和量的CTE RNA的存在引起的mRNA输出阻断。因此，TAP与其酵母同源物Mex67p一样，是真正的mRNA核输出介体。TAP是第二种直接参与其靶RNA输出的细胞RNA结合蛋白。
The constitutive transport element (CTE) of the type D retroviruses promotes nuclear export of unspliced viral RNAs apparently by recruiting host factor(s) required for export of cellular messenger RNAs. Here, we report the identification of TAP as the cellular factor that specifically binds to wild-type CTE but not to export-deficient CTE mutants. Microinjection experiments performed in Xenopus oocytes demonstrate that TAP directly stimulates CTE-dependent export. Furthermore, TAP overcomes the mRNA export block caused by the presence of saturating amounts of CTE RNA. Thus, TAP, like its yeast homolog Mex67p, is a bona fide mRNA nuclear export mediator. TAP is the second cellular RNA binding protein shown to be directly involved in the export of its target RNA.