Kiss-Toth E, Paca-uccaralertkun S, Unk I, Boros I
Institute of Biochemistry, Hungarian Academy of Sciences, Szeged.
Nucleic Acids Res. 1993 Aug 11;21(16):3677-82. doi: 10.1093/nar/21.16.3677.
The trans activator protein of Bovine Leukaemia Virus (tax) increases the rate of transcription from the virus promoter through 21 bp sequences located in three tandem copies in the virus LTR. Based on data obtained by three different experimental approaches we concluded that the central CRE-like motif found in each of the BLV 21 bp repeats plays an important and indispensable role in tax mediated trans activation. These include (i) in vivo analysis of the function of mutant 21 bp sequences in transient transfection, (ii) gel mobility shift assay to show that CREB binds to BLV 21 bp repeats in vitro and (iii) the demonstration that the production of antisense CREB mRNA inhibits tax trans activation. Further studies with different deletion mutant CREB proteins suggest that although CREB alpha can interact with factors involved in BLV trans activation, it does not promote transcription initiation; consequently some other member/s of the CREB/ATF family must be involved.
牛白血病病毒（tax）的反式激活蛋白通过位于病毒长末端重复序列（LTR）中三个串联拷贝的21bp序列提高病毒启动子的转录速率。基于通过三种不同实验方法获得的数据，我们得出结论，在每个BLV 21bp重复序列中发现的中央CRE样基序在tax介导的反式激活中起重要且不可或缺的作用。这些方法包括：（i）在瞬时转染中对突变21bp序列功能的体内分析；（ii）凝胶迁移率变动分析，以显示CREB在体外与BLV 21bp重复序列结合；（iii）证明反义CREB mRNA的产生抑制tax反式激活。对不同缺失突变CREB蛋白的进一步研究表明，尽管CREBα可以与参与BLV反式激活的因子相互作用，但它不促进转录起始；因此，CREB/ATF家族的其他一些成员必定参与其中。
