Enhancer activation via TCP and HD-ZIP and repression by Dof transcription factors mediate giant cell-specific expression
Enhancer activation via TCP and HD-ZIP and repression by Dof transcription factors mediate giant cell-specific expression
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DOI：
10.1093/plcell/koad054
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发表时间：
2023-03-14
期刊：
影响因子：
11.6
通讯作者：
Roeder, Adrienne H. K.
中科院分区：
文献类型：
--
作者：
Hong, Lilan;Rusnak, Byron;Roeder, Adrienne H. K.
正确的细胞类型身份依赖于基因表达的高度协调调节。调控元件如增强子可以产生细胞类型特异性表达模式，但特异性的机制还不清楚。我们以前确定了一个增强子区域能够驱动巨细胞，这是大的，高度内复制的细胞在拟南芥萼片表皮的特异性表达。在这项研究中，我们使用巨细胞增强子作为模型来理解促进细胞类型特异性表达的调控逻辑。我们对增强子的解剖揭示了巨细胞特异性主要是通过两个激活子和一个抑制子的组合来介导的。HD-ZIP和TCP转录因子参与整个表皮的表达激活。HD-ZIP转录因子基因在巨细胞中的高表达促进了巨细胞中增强子驱动的更高表达。Dof转录因子抑制增强子的活性，使得只有巨细胞保持增强子活性。因此，我们的数据是一致的概念模型，即细胞类型特异性表达出现的三个转录因子家族激活和抑制表皮cells.Dissection的增强子，驱动巨细胞特异性表达的联合活动揭示了通过TCP和HD-ZIPs和抑制通过Dof转录因子联合收割机激活结合介导细胞类型特异性。
Proper cell-type identity relies on highly coordinated regulation of gene expression. Regulatory elements such as enhancers can produce cell type-specific expression patterns, but the mechanisms underlying specificity are not well understood. We previously identified an enhancer region capable of driving specific expression in giant cells, which are large, highly endoreduplicated cells in the Arabidopsis thaliana sepal epidermis. In this study, we use the giant cell enhancer as a model to understand the regulatory logic that promotes cell type-specific expression. Our dissection of the enhancer revealed that giant cell specificity is mediated primarily through the combination of two activators and one repressor. HD-ZIP and TCP transcription factors are involved in the activation of expression throughout the epidermis. High expression of HD-ZIP transcription factor genes in giant cells promoted higher expression driven by the enhancer in giant cells. Dof transcription factors repressed the activity of the enhancer such that only giant cells maintained enhancer activity. Thus, our data are consistent with a conceptual model whereby cell type-specific expression emerges from the combined activities of three transcription factor families activating and repressing expression in epidermal cells.Dissection of an enhancer that drives giant cell-specific expression reveals that activation via TCPs and HD-ZIPs and repression via Dof transcription factors combine to mediate cell type specificity.