State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.
CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China.
EMBO J. 2020 Oct 15;39(20):e105047. doi: 10.15252/embj.2020105047. Epub 2020 Sep 14.
Proper regulation of homeotic gene expression is critical for stem cell fate in both plants and animals. In Arabidopsis thaliana, the WUSCHEL (WUS)-RELATED HOMEOBOX 5 (WOX5) gene is specifically expressed in a group of root stem cell organizer cells called the quiescent center (QC) and plays a central role in QC specification. Here, we report that the SEUSS (SEU) protein, homologous to the animal LIM-domain binding (LDB) proteins, assembles a functional transcriptional complex that regulates WOX5 expression and QC specification. SEU is physically recruited to the WOX5 promoter by the master transcription factor SCARECROW. Subsequently, SEU physically recruits the SET domain methyltransferase SDG4 to the WOX5 promoter, thus activating WOX5 expression. Thus, analogous to its animal counterparts, SEU acts as a multi-adaptor protein that integrates the actions of genetic and epigenetic regulators into a concerted transcriptional program to control root stem cell organizer specification.
正确调控同源基因的表达对植物和动物干细胞的命运至关重要。在拟南芥中，WUSCHEL（WUS）相关同源盒 5 基因（WOX5）特异性地在一组被称为静止中心（QC）的根干细胞组织者细胞中表达，在 QC 特化中发挥核心作用。在这里，我们报告说，SEUSS（SEU）蛋白与动物 LIM 结构域结合（LDB）蛋白同源，组装了一个功能性转录复合物，调节 WOX5 的表达和 QC 的特化。SEU 由主转录因子 SCARECROW 直接招募到 WOX5 启动子上。随后，SEU 直接招募 SET 结构域甲基转移酶 SDG4 到 WOX5 启动子上，从而激活 WOX5 的表达。因此，与动物同源物类似，SEU 作为一种多接头蛋白，将遗传和表观遗传调节剂的作用整合到协调的转录程序中，以控制根干细胞组织者的特化。
