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Abstract：
Transcription factors (TFs) are proteins which bind to specific DNA sequences and thus participate in the regulation of the initiation of transcription. We report in this communication our observations that several of these proteins interact with lipid membranes and form ion-permeable channels. For each of the TFs that we studied, the single channel conductance was distinctively different, i.e. each TF had its own electrical signature. More importantly, we show for the first time that addition of cognate double-stranded DNA sequences leads to a specific response: an increase in the conductance of the TF-containing membrane. Strikingly, the effect of cognate DNA was observed when it was added to the trans-side of the membrane (opposite to where the TF was added), strongly suggesting that the TFs span the membrane and that the DNA-binding domain is trans-accessible. Alterations in the primary structure of the TF factors in their basic and DNA-binding regions change the characteristics of the conductance of the protein-containing membranes as well as the response to DNA addition, reinforcing the notion that the changes we measure are due to specific interactions.
摘要：
转录因子（TF）是与特定DNA序列结合的蛋白质，因此参与转录起始的调节。我们在此通讯中报告了我们的观察结果，这些蛋白质中的几种与脂质膜相互作用并形成离子可渗透通道。对于我们研究的每个TFs，单通道电导明显不同，即,每个TF具有其自己的电签名。更重要的是,我们首次表明，添加同源双链DNA序列会导致特定的反应：含TF膜的电导增加。引人注目的是，当将同源DNA添加到膜的反式侧时（与添加TF的位置相反）观察到同源DNA的效果，强烈表明TFs跨越膜，并且DNA结合结构域是反式可接近的。TF因子在其基本和DNA结合区域的一级结构的改变改变了含蛋白质膜的电导特性以及对DNA添加的响应，强化了这样一种观念，即我们衡量的变化是由于特定的相互作用。
