Transcription factor interaction with COMPASS-like complex regulates histone H3K4 trimethylation for specific gene expression in plants
Transcription factor interaction with COMPASS-like complex regulates histone H3K4 trimethylation for specific gene expression in plants
复制标题
转录因子与 COMPASS 样复合物的相互作用调节组蛋白 H3K4 三甲基化以实现植物中的特定基因表达
DOI：
10.1073/pnas.1419703112
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发表时间：
2015-03-03
影响因子：
11.1
通讯作者：
Liu, Jian-Xiang
中科院分区：
文献类型：
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作者：
Song, Ze-Ting;Sun, Le;Liu, Jian-Xiang
在后生动物中，在早期延伸过程中Pol II的暂停是转录调节的一种普遍调节机制。然而，前起始复合体（PIC）的组装是更重要的转录植物。染色质重塑和组蛋白修饰被认为对于蛋白质因子进入潜在的DNA序列是重要的。然而，组蛋白修饰是如何在活性启动子特异性和及时地产生的还不太清楚。COMPASS样复合物在PIC组装和组蛋白H3 K4三甲基化中起着关键作用。我们发现拟南芥转录因子bZIP 28/bZIP 60与COMPASS样成分在体外和体内相互作用。我们提出了一个一般模型，组蛋白H3 K4三甲基化是如何在诱导型基因表达过程中，通过使用内质网（ER）应激反应系统在拟南芥植物。未折叠或错误折叠的蛋白质的积累引起内质网（ER）应激，其激活一组ER膜相关转录因子用于蛋白质稳态调节。先前的全基因组染色质免疫沉淀分析显示组蛋白H3 K4三甲基化（H3 K4 me 3）和活性基因表达之间有很强的相关性。然而，组蛋白修饰复合物如何特异性且及时地被募集到活性启动子中仍然未知。使用ER应激反应基因表达作为模型系统，我们证明了序列特异性转录因子与COMPASS样组件相互作用，并影响H3 K4 me 3在拟南芥中特定靶位点的形成。基因表达谱分析表明，膜相关碱性亮氨酸拉链（bZIP）转录因子bZIP 28和bZIP 60调节大多数ER应激反应基因。bZIP 28和bZIP 60的功能丧失损害了H3 K4 me 3在ER应激反应基因启动子区域上的占据。此外，体外下拉测定和体内双分子荧光互补（BiFC）实验表明，bZIP 28和bZIP 60与Ash 2和WDR 5a相互作用，这两者都是核心COMPASS样组分。Ash 2或WDR 5a的敲低表达降低了几个ER应激反应基因的表达。已知COMPASS样复合物与组蛋白甲基转移酶相互作用以促进前起始复合物（PIC）组装并在转录延伸期间产生H3 K4 me 3。因此，我们的数据表明，ER应激刺激通过转录因子和COMPASS样组分之间的相互作用，导致PIC的形成和H3 K4 me 3标记在特定启动子处的沉积。
Significance In metazoans, pausing of Pol II during early elongation is a widespread regulatory mechanism for transcription regulation. However, preinitiation complex (PIC) assembly is more important for transcription in plants. Chromatin remodeling and histone modifications are considered important for access of protein factors to the underlying DNA sequences. However, how histone modifications are specifically and timely generated at active promoters is less understood. COMPASS-like complex plays a critical role in PIC assembly and histone H3K4 trimethylation. We found that Arabidopsis transcription factors bZIP28/bZIP60 interact with COMPASS-like components both in vitro and in vivo. We present a general model on how histone H3K4 trimethylation is specifically formed during inducible gene expression by using the endoplasmic reticulum (ER) stress response system in Arabidopsis plants. Accumulation of unfolded or misfolded proteins causes endoplasmic reticulum (ER) stress, which activates a set of ER membrane-associated transcription factors for protein homeostasis regulation. Previous genome-wide chromatin immunoprecipitation analysis shows a strong correlation between histone H3K4 trimethylation (H3K4me3) and active gene expression. However, how the histone modification complex is specifically and timely recruited to the active promoters remains unknown. Using ER stress responsive gene expression as a model system, we demonstrate that sequence-specific transcription factors interact with COMPASS-like components and affect H3K4me3 formation at specific target sites in Arabidopsis. Gene profiling analysis reveals that membrane-associated basic leucine zipper (bZIP) transcription factors bZIP28 and bZIP60 regulate most of the ER stress responsive genes. Loss-of-functions of bZIP28 and bZIP60 impair the occupancy of H3K4me3 on promoter regions of ER stress responsive genes. Further, in vitro pull-down assays and in vivo bimolecular fluorescence complementation (BiFC) experiments show that bZIP28 and bZIP60 interact with Ash2 and WDR5a, both of which are core COMPASS-like components. Knockdown expression of either Ash2 or WDR5a decreased the expression of several ER stress responsive genes. The COMPASS-like complex is known to interact with histone methyltransferase to facilitate preinitiation complex (PIC) assembly and generate H3K4me3 during transcription elongation. Thus, our data shows that the ER stress stimulus causes the formation of PIC and deposition of H3K4me3 mark at specific promoters through the interaction between transcription factor and COMPASS-like components.