The tax protein-DNA interaction is essential for HTLV-I transactivation in vitro.
The tax protein-DNA interaction is essential for HTLV-I transactivation in vitro.
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Tax 蛋白-DNA 相互作用对于 HTLV-I 体外反式激活至关重要。
DOI：
10.1006/jmbi.1999.2969
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发表时间：
1999
影响因子：
5.6
通讯作者：
Nyborg,JK
中科院分区：
文献类型：
--
作者：
Lenzmeier,BA;Baird,EE;Dervan,PB;Nyborg,JK
人类T细胞白血病病毒1型(HTLV-I)编码的Tax蛋白通过与病毒启动子上的三个重复DNA元件相互作用而增强病毒基因的转录。这些元件被称为病毒Cres，由一个非共识的八个碱基对的环状AMP反应元件(CRE)组成，其两侧紧邻着富含鸟嘌呤和胞嘧啶残基的序列。最近的生化实验表明，在细胞蛋白CREB存在的情况下，TAX通过与小沟槽的相互作用直接与病毒Cre G+C富含序列结合。为了确定Tax-DNA相互作用的功能意义，我们合成了与病毒Cres中富含G+C的序列特异结合的少量沟槽结合的吡咯咪唑多酰胺。在聚酰胺专门保护富含G+C的序列不受MPE：Fe切割的浓度下，聚酰胺阻止了Tax-DNA的相互作用。在完全相同的浓度下，聚酰胺在体外特异性地抑制TAX的反式激活，而不改变CREB激活的转录或来自同一启动子的基础转录。综上所述，这些数据提供了强有力的证据，表明Tax-病毒Cre相互作用在体外对Tax功能是必不可少的，并表明靶向破坏Tax-DNA小槽与聚酰胺的相互作用可能为抑制体内病毒复制提供一种新的方法。
The human T-cell leukemia virus type-1 (HTLV-I)-encoded Tax protein enhances viral gene transcription through interaction with three repeated DNA elements located in the viral promoter. These elements, called viral CREs, are composed of an off-consensus eight base-pair cyclic AMP response element (CRE), immediately flanked by sequences that are rich in guanine and cytosine residues. Recent biochemical experiments have demonstrated that in the presence of the cellular protein CREB, Tax directly binds the viral CRE G+C-rich sequences via interaction with the minor groove. To determine the functional significance of the Tax-DNA interaction, we synthesized minor groove-binding pyrrole-imidazole polyamides which bind specifically to the G+C-rich sequences in the viral CREs. At concentrations where the polyamides specifically protect the G+C-rich sequences from MPE:Fe cleavage, the polyamides block the Tax-DNA interaction. At precisely these same concentrations, the polyamides specifically inhibit Tax transactivation in vitro, without altering CREB-activated transcription or basal transcription from the same promoter. Together, these data provide strong evidence that Tax-viral CRE interaction is essential for Tax function in vitro, and suggest that targeted disruption of the Tax-DNA minor groove interaction with polyamides may provide a novel approach for inhibiting viral replication in vivo.