Specific binding of polypyrimidine tract binding protein and hnRNP A1 to HIV-1 CRS elements
Specific binding of polypyrimidine tract binding protein and hnRNP A1 to HIV-1 CRS elements
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DOI：
10.1007/bf00284648
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发表时间：
1996-01-01
期刊：
影响因子：
1.6
通讯作者：
Rosenblatt, JD
中科院分区：
文献类型：
--
作者：
Black, AC;Luo, J;Rosenblatt, JD
人类免疫缺陷病毒（HIV） Rev和人类t细胞白血病病毒（HTLV） Rex蛋白调节病毒RNA加工。这两种蛋白至少在一定程度上通过逆转内含子RNA序列（称为cia作用抑制（CRS）序列）的抑制作用来克服对病毒结构基因表达的阻断。以HTLV II型（HTLV-II）为模型，我们最近发现5'长末端重复序列（LTR） CRS的功能与聚嘧啶束结合（PTB）蛋白（也称为hnRNP I）和hnRNP A1与CRS RNA的体外结合相关（1,2）。利用紫外线（UV）交联蛋白与单克隆抗hnRNP抗体，我们现在证明hnRNP I和hnRNP A1与两种不同的HIV-1 CRS RNA结合。此外，我们发现结合HIV-1 CRS rna的hnRNP I和hnRNP A1可以通过电泳迁移转移试验(EMSA)/UV交联试验被HTLV-II CRS rna特异性竞争。hnRNP I和hnRNP A1与HIV-1和HTLV-II CRS rna的结合表明，这些蛋白在CRS功能中的作用可能分别受到Rev和Rex蛋白的影响。
The human immunodeficiency virus (HIV) Rev and human T-cell leukemia virus (HTLV) Rex proteins regulate viral RNA processing. Both proteins act to overcome the block to viral structural gene expression, at least in part, by reversing the inhibitory effect of intronic RNA sequences, termed cia-acting repressive (CRS) sequences. Using HTLV type II (HTLV-II) as a model, we recently showed that the function of a 5' long terminal repeat (LTR) CRS correlates with in vitro binding by both polypyrimidine tract binding (PTB) protein (also known as hnRNP I) and hnRNP A1 to CRS RNA (1,2). Using radioimmunoprecipitation of proteins ultraviolet (UV) crosslinked to each HIV CRS RNA with monoclonal anti-hnRNP antibodies, we now demonstrate that hnRNP I and hnRNP A1 bind to two different HIV-1 CRS RNAs. In addition, we show that hnRNP I and hnRNP A1 binding to HIV-1 CRS RNAs can be specifically competed by HTLV-II CRS RNAs using electrophoretic mobility shift assay (EMSA)/UV crosslinking assays. Binding by both hnRNP I and hnRNP A1 to HIV-1 and HTLV-II CRS RNAs suggests a role for these proteins in CRS function that may be influenced by the Rev and Rex proteins, respectively.