THE SPI-1/PU.1 AND SPI-B ETS FAMILY TRANSCRIPTION FACTORS AND THE RECOMBINATION SIGNAL BINDING-PROTEIN RBP-J-KAPPA INTERACT WITH AN EPSTEIN-BARR-VIRUS NUCLEAR ANTIGEN-2 RESPONSIVE CIS-ELEMENT
THE SPI-1/PU.1 AND SPI-B ETS FAMILY TRANSCRIPTION FACTORS AND THE RECOMBINATION SIGNAL BINDING-PROTEIN RBP-J-KAPPA INTERACT WITH AN EPSTEIN-BARR-VIRUS NUCLEAR ANTIGEN-2 RESPONSIVE CIS-ELEMENT
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DOI：
10.1002/j.1460-2075.1994.tb06900.x
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发表时间：
1994-12-01
期刊：
影响因子：
11.4
通讯作者：
MOREAUGACHELIN, F
中科院分区：
文献类型：
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作者：
LAUX, G;ADAM, B;MOREAUGACHELIN, F
eb病毒（EBV）在体外非常有效地使静止的人B细胞永生化。EBV核蛋白EBNA2在这一过程中是绝对必需的。它还能激活细胞和病毒基因的转录。由于EBNA2的转化和反激活功能不能分离，因此假设EBNA2通过其反激活电位有助于B细胞的永生化。对病毒双向LMP/TP2启动子区域内80 bp EBNA2响应顺式元件的突变分析发现了两个序列元件，它们都是EBNA2转激活所必需的。这些序列包含Spi-1癌蛋白和重组信号结合蛋白RBP-J kappa的推定一致的结合位点，RBP-J kappa是果蝇无毛抑制因子的同源物。电泳迁移率转移实验表明，Ets转录因子家族成员Spi-1和Spi-B与一个序列元件具有高亲和力结合。另一个元件与RBP-J kappa结合的亲和力较低。此外，共转染表明，类似的SV40 Spi-1响应元件替代双向LMP/TP2启动子中的Spi-1/Spi-B结合位点并不会损害其在ebna2介导的交易激活中的功能。由此可见，转录调控因子Spi-1和Spi-B以及RBP-J kappa在EBNA2反激活LMP/TP2启动子中发挥了重要作用，从而在EBV对B细胞的永生化中发挥了重要作用。
Epstein - Barr virus (EBV) immortalizes resting human B cells very efficiently in vitro. The EBV nuclear protein EBNA2 is absolutely required for this process. It also activates transcription of cellular, as well as viral, genes. It is assumed that EBNA2 contributes to B cell immortalization by its transactivating potential, since its transforming and transactivating functions could not be separated. Mutational analysis of the 80 bp EBNA2 responsive cis-element within the viral bi-directional LMP/TP2 promoter region identified two sequence elements, which are both essential for transactivation by EBNA2. These sequences harbour putative consensus binding sites for Spi-1 oncoprotein and recombination signal binding protein RBP-J kappa, the homologue of Drosophila Suppressor of Hairless. Electrophoretic mobility shift assays demonstrated the high affinity binding of Spi-1 and Spi-B, both members of the Ets family of transcription factors, to one sequence element. The other element bound RBP-J kappa with low affinity. In addition, co-transfections showed that the replacement of the Spi-1/Spi-B binding site in the bi-directional LMP/TP2 promoter by the analogous SV40 Spi-1 responsive element did not impair its function on EBNA2-mediated transactivation. It is concluded that the transcriptional regulators Spi-1 and Spi-B as well as RBP-J kappa play an essential role in transactivating the LMP/TP2 promoter by EBNA2 and therefore in the immortalization of B cells by EBV.