Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China.
Plant Mol Biol. 2018 Dec;98(6):495-506. doi: 10.1007/s11103-018-0791-0. Epub 2018 Nov 8.
Trithorax-group Protein ARABIDOPSIS TRITHORAX5 modulates the glucose response. Glucose is an evolutionarily conserved modulator from unicellular microorganisms to multicellular animals and plants. Extensive studies have shown that the Trithorax-group proteins (TrxGs) play essential roles in different biological processes by affecting histone modifications and chromatin structures. However, whether TrxGs function in the glucose response and how they achieve the control of target genes in response to glucose signaling in plants remain unknown. Here, we show that the Trithorax-group Protein ARABIDOPSIS TRITHORAX5 (ATX5) affects the glucose response and signaling. atx5 loss-of-function mutants display glucose-oversensitive phenotypes compared to the wild-type (WT). Genome-wide RNA-sequencing analyses have revealed that ATX5 impacts the expression of a subset of glucose signaling responsive genes. Intriguingly, we have established that ATX5 directly controls the expression of HY1 by trimethylating H3 lysine 4 of the Arabidopsis Heme Oxygenase1 (HY1) locus. Glucose signaling causes the suppression of ATX5 activity and subsequently reduces the H3K4me3 levels at the HY1 locus, thereby leading to the increased expression of ABSCISIC ACID-INSENSITIVE4 (ABI4). This result suggests that an important ATX5-HY1-ABI4 regulatory module governs the glucose response. This idea is further supported by genetic evidence showing that an atx5 hy1-100 abi4 triple mutant showed a similar glucose-insensitive phenotype as compared to that of the abi4 single mutant. Our findings show that a novel ATX5-HY1-ABI4 module controls the glucose response in Arabidopsis thaliana.
类转录激活因子蛋白 ARABIDOPSIS TRITHORAX5 调节葡萄糖反应。葡萄糖是一种从单细胞微生物到多细胞动物和植物中保守的调节剂。广泛的研究表明，类转录激活因子蛋白（TrxGs）通过影响组蛋白修饰和染色质结构，在不同的生物学过程中发挥着重要作用。然而，TrxGs 是否在葡萄糖反应中起作用，以及它们如何在植物中响应葡萄糖信号来实现对靶基因的控制，仍然未知。在这里，我们表明类转录激活因子蛋白 ARABIDOPSIS TRITHORAX5（ATX5）影响葡萄糖反应和信号转导。atx5 功能丧失突变体与野生型（WT）相比表现出葡萄糖超敏表型。全基因组 RNA 测序分析表明，ATX5 影响了一组葡萄糖信号响应基因的表达。有趣的是，我们已经确定 ATX5 通过三甲基化拟南芥血红素加氧酶 1（HY1）基因座的组蛋白 H3 赖氨酸 4 直接控制 HY1 的表达。葡萄糖信号导致 ATX5 活性的抑制，随后降低 HY1 基因座处的 H3K4me3 水平，从而导致 ABSCISIC ACID-INSENSITIVE4（ABI4）的表达增加。这一结果表明，一个重要的 ATX5-HY1-ABI4 调控模块控制着葡萄糖反应。这一观点得到了遗传证据的进一步支持，表明与 abi4 单突变体相比，atx5 hy1-100 abi4 三重突变体表现出类似的葡萄糖不敏感表型。我们的研究结果表明，一个新的 ATX5-HY1-ABI4 模块控制着拟南芥中的葡萄糖反应。
