Carles Cristel C, Fletcher Jennifer C
Plant Gene Expression Center, United States Department of Agriculture/University of California at Berkeley, Albany, California 94710, USA.
Genes Dev. 2009 Dec 1;23(23):2723-8. doi: 10.1101/gad.1812609.
During development, trithorax group (trxG) chromatin remodeling complexes counteract repression by Polycomb group (PcG) complexes to sustain active expression of key regulatory genes. Although PcG complexes are well characterized in plants, little is known about trxG activities. Here we demonstrate that the Arabidopsis SAND (Sp100, AIRE-1, NucP41/75, DEAF-1) domain protein ULTRAPETALA1 (ULT1) functions as a trxG factor that counteracts the PcG-repressive activity of CURLY LEAF. In floral stem cells, ULT1 protein associates directly with the master homeotic locus AGAMOUS, inducing its expression by regulating its histone methylation status. Our analysis introduces a novel mechanism that mediates epigenetic switches controlling post-embryonic stem cell fates in plants.
在发育过程中，三胸复合体（trxG）染色质重塑复合物可对抗多梳复合体（PcG）的抑制作用，以维持关键调控基因的活性表达。尽管PcG复合体在植物中已得到充分研究，但对于trxG的活性却知之甚少。在此，我们证明拟南芥SAND（Sp100、AIRE-1、NucP41/75、DEAF-1）结构域蛋白超花瓣1（ULT1）作为一种trxG因子，可对抗卷曲叶（CLF）的PcG抑制活性。在花干细胞中，ULT1蛋白直接与主要同源异型基因座AGAMOUS结合，通过调节其组蛋白甲基化状态诱导其表达。我们的分析引入了一种新机制，该机制介导了控制植物胚后干细胞命运的表观遗传转换。
