The GATA factor AreA is essential for chromatin remodelling in a eukaryotic bidirectional promoter
The GATA factor AreA is essential for chromatin remodelling in a eukaryotic bidirectional promoter
复制标题
DOI：
10.1093/emboj/18.6.1584
复制
发表时间：
1999-03-15
期刊：
影响因子：
11.4
通讯作者：
Scazzocchio, C
中科院分区：
文献类型：
--
作者：
Muro-Pastor, MI;Gonzalez, R;Scazzocchio, C
构巢曲霉相连的 niiA 和 niaD 基因的转录方式不同。这些基因的表达受到双重控制系统的控制，它们被硝酸盐诱导并被铵抑制。 AreA 在没有铵的情况下介导去抑制，而 NirA 可能介导硝酸盐诱导。在 10 个 GATA 位点中，一个中心簇（位点 5-8）负责两个基因上启动子的大约 80% 的转录活性。我们显示，即使在抑制条件下，AreA 蛋白在体内也占据了位点 5。位点 5-8 位于预设的无核小体区域。在表达条件下，发生剧烈的核小体重排，并且中央区域两侧的至少五个核小体的定位丢失。重塑严格依赖于活性areA基因产物的存在，并且独立于NirA特异性和必需的转录因子。因此，核小体重塑独立于 niiA-niaD 启动子的转录激活。所呈现的结果对 NirA 作为硝酸盐诱导信号的独特转导器的作用产生了怀疑。我们首次在体内证明了 GATA。该因子直接参与染色质重塑。
The linked niiA and niaD genes of Aspergillus nidulans are transcribed divergently. The expression of these genes is subject to a dual control system, They are induced by nitrate and repressed by ammonium. AreA mediates derepression in the absence of ammonium and NirA supposedly mediates nitrate induction. Out of 10 GATA sites, a central cluster (sites 5-8) is responsible for similar to 80% of the transcriptional activity of the promoter on both genes. We show occupancy in viva of site 5 by the AreA protein, even under conditions of repression. Sites 5-8 are situated in a pre-set nucleosome-free region, Under conditions of expression, a drastic nucleosomal rearrangement takes place and the positioning of at least five nucleosomes flanking the central region is lost. Remodelling is strictly dependent on the presence of an active areA gene product, and independent from the NirA-specifie and essential transcription factor. Thus, nucleosome remodelling is independent from the transcriptional activation of the niiA-niaD promoter The results presented cast doubts on the role of NirA as the unique transducer of the nitrate induction signal. We demonstrate, for the first time in vivo, that a GATA. factor is involved directly in chromatin remodelling.