Caro Elena, Castellano M Mar, Gutierrez Crisanto
Centro de Biologia Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
Nature. 2007 May 10;447(7141):213-7. doi: 10.1038/nature05763. Epub 2007 Apr 22.
Cell proliferation and cell fate decisions are strictly coupled processes during plant embryogenesis and organogenesis. In the Arabidopsis thaliana root epidermis, expression of the homeobox GLABRA2 (GL2) gene determines hair/non-hair cell fate. This requires signalling of positional information from the underlying cortical layer, complex transcriptional regulation and a change in chromatin accessibility. However, the molecular connections among these factors and with cell division are not known. Here we have identified a GL2-expression modulator, GEM, as an interactor of CDT1, a DNA replication protein. GEM also interacts with TTG1 (TRANSPARENT TESTA GLABRA1), a WD40-repeat protein involved in GL2-dependent cell fate decision, and modulates both cell division and GL2 expression. Here we show that GEM participates in the maintenance of the repressor histone H3K9 methylation status of root patterning genes, providing a link between cell division, fate and differentiation during Arabidopsis root development.
在植物胚胎发生和器官发生过程中，细胞增殖和细胞命运决定是严格耦合的过程。在拟南芥根表皮中，同源异型盒基因GLABRA2（GL2）的表达决定了毛细胞/非毛细胞的命运。这需要来自下层皮层的位置信息信号传导、复杂的转录调控以及染色质可及性的变化。然而，这些因素之间以及与细胞分裂的分子联系尚不清楚。在这里，我们鉴定出一种GL2表达调节剂GEM，它是DNA复制蛋白CDT1的相互作用因子。GEM还与TTG1（透明种皮GLABRA1）相互作用，TTG1是一种参与GL2依赖性细胞命运决定的WD40重复蛋白，并调节细胞分裂和GL2表达。在这里，我们表明GEM参与维持根模式基因的抑制性组蛋白H3K9甲基化状态，为拟南芥根发育过程中的细胞分裂、命运和分化之间提供了联系。
