Gcn4 occupancy of open reading frame regions results in the recruitment of chromatin-modifying complexes but not the mediator complex
Gcn4 occupancy of open reading frame regions results in the recruitment of chromatin-modifying complexes but not the mediator complex
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DOI：
10.1038/sj.embor.embor931
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发表时间：
2003-09-01
期刊：
影响因子：
7.7
通讯作者：
Thireos, G
中科院分区：
文献类型：
--
作者：
Topalidou, I;Thireos, G
真核生物转录激活子通常识别短的DNA基序，这些基序不仅位于启动子区域内，而且分散在整个基因组中。假设激活子在非启动子区域的功能是浪费的，可能是有害的，人们可以问这种结合是否以某种方式被阻止，或者转录是否在下游步骤被阻断。在这里，我们证明了酵母转录激活子Gcn4在体内与几个非启动子共染色质位点相关。这种关联导致SAGA （Spt3/Ada/Gcn5/乙酰转移酶）复合物的募集，以及随之而来的Gcn5组蛋白乙酰转移酶的活性。Swi/Snf核小体重构复合体的功能性募集在定位核小体的位点上也很明显。我们表明，这种共激活物复合物的组装不具有生产力，因为除了TATA盒之外，缺乏核心启动子元件，而这些元件是稳定的介质招募所必需的。
Eukaryotic transcriptional activators usually recognize short DNA motifs, which are not only located within promoter regions, but also scattered throughout the genome. Assuming that the function of activators at non-promoter regions is wasteful and perhaps harmful, one can ask whether such binding is somehow prevented or if transcription is blocked at a downstream step. Here, we show that the yeast transcriptional activator Gcn4 is associated in vivo with several non-promoter euchromatic sites. This association results in the recruitment of the SAGA (Spt3/Ada/Gcn5/ acetyltransferase) complex and the consequent activity of the Gcn5 histone acetyltransferase. The functional recruitment of the Swi/Snf nucleosome-remodelling complex was also evident at sites located in positioned nucleosomes. We show that this assemblage of coactivator complexes is not productive because of the absence of core promoter elements, other than the TATA box, that are required for stable mediator recruitment.