ATX-1, an Arabidopsis homolog of trithorax, activates flower homeotic genes
ATX-1, an Arabidopsis homolog of trithorax, activates flower homeotic genes
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DOI：
10.1016/s0960-9822(03)00243-4
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发表时间：
2003-04-15
期刊：
影响因子：
9.2
通讯作者：
Avramova, Z
中科院分区：
文献类型：
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作者：
Alvarez-Venegas, R;Pien, S;Avramova, Z
背景资料：三胸基因（trxG）和多梳基因（PcG）在果蝇中的调节功能最为人所知，它们控制同源异型基因的表达。植物和动物被认为是独立进化出多细胞的。虽然同源异型基因控制着动物和植物的器官特性，但它们是不相关的。尽管如此，一些植物同源异型基因受到植物基因的负调控，类似于来自动物PcG的阻遏物。然而，植物激活调节器的trxG还没有characterized.Results：我们提供的遗传，分子，功能和生化证据表明，拟南芥基因，ATK1，这是类似的果蝇trx，调节花器官发育。这些影响是特定的：结构和功能相关的花同源异型基因受到不同的控制。我们表明，ATX1是一个表观遗传调节与组蛋白H3K4甲基转移酶活性。这是在植物中报道的这种酶活性的第一个例子，并且与果蝇和酵母三胸同源物相反，ATX 1可以在没有额外蛋白质的情况下甲基化。在其甲基化H3K4作为一种重组蛋白的能力，ATX 1是类似于人类homolog.Conclusions：ATX 1的功能作为同源异型基因的激活剂，如Trithorax在动物系统。ATX1-SET结构域的组蛋白甲基化活性表明，这些作用的分子基础是ATX1修饰染色质结构的能力。我们的研究结果表明，尽管它们的目标的不同结构性质的动物和植物王国之间的trxG功能的保护。
Background: The genes of the trithorax (trxG) and Polycomb groups (PcG) are best known for their regulatory functions in Drosophila, where they control homeotic gene expression. Plants and animals are thought to have evolved multicellularity independently. Although homeotic genes control organ identity in both animals and plants, they are unrelated. Despite this fact, several plant homeotic genes are negatively regulated by plant genes similar to the repressors from the animal PcG. However, plant-activating regulators of the trxG have not been characterized.Results: We provide genetic, molecular, functional, and biochemical evidence that an Arabidopsis gene, ATK1, which is similar to the Drosophila trx, regulates floral organ development. The effects are specific: structurally and functionally related flower homeotic genes are under different control. We show that ATX1 is an epigenetic regulator with histone H3K4 methyltransferase activity. This is the first example of this kind of enzyme activity reported in plants, and, in contrast to the Drosophila and the yeast trithorax homologs, ATX1 can methylate in the absence of additional proteins. In its ability to methylate H3K4 as a recombinant protein, ATX1 is similar to the human homolog.Conclusions: ATX1 functions as an activator of homeotic genes, like Trithorax in animal systems. The histone methylating activity of the ATX1-SET domain argues that the molecular basis of these effects is the ability of ATX1 to modify chromatin structure. Our results suggest a conservation of trxG function between the animal and plant kingdoms despite the different structural nature of their targets.