Essential Role of the Glycosyltransferase Sxc/Ogt in Polycomb Repression
Essential Role of the Glycosyltransferase Sxc/Ogt in Polycomb Repression
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DOI：
10.1126/science.1169727
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发表时间：
2009-07-03
期刊：
影响因子：
56.9
通讯作者：
Mueller, Juerg
中科院分区：
文献类型：
--
作者：
Gambetta, Maria Cristina;Oktaba, Katarzyna;Mueller, Juerg
Polycomb族蛋白是一类保守的转录抑制因子，控制着动植物的发育。在这里，我们发现，果蝇Polycomb组基因超级性梳（sxc）编码Ogt，高度保守的糖基转移酶，催化添加N-乙酰葡萄糖胺（GlcNAc）的蛋白质在动物和植物。果蝇全基因组分析表明，GlcNAc修饰的蛋白质在Polycomb反应元件高度富集。在不同的Polycomb族蛋白中，Polyhomeotic在体内被Sxc/Ogt糖基化。sxc/Ogt-无效突变体缺乏O-连接的GlcNAc化，即使Polycomb组蛋白复合物结合在其靶位点，也不能维持Polycomb转录抑制。Polycomb阻遏似乎是果蝇中Sxc/Ogt的关键功能，并且可能由Polyhomeotic的糖基化介导。
Polycomb group proteins are conserved transcriptional repressors that control animal and plant development. Here, we found that the Drosophila Polycomb group gene super sex combs (sxc) encodes Ogt, the highly conserved glycosyltransferase that catalyzes the addition of N-acetylglucosamine (GlcNAc) to proteins in animals and plants. Genome-wide profiling in Drosophila revealed that GlcNAc-modified proteins are highly enriched at Polycomb response elements. Among different Polycomb group proteins, Polyhomeotic is glycosylated by Sxc/Ogt in vivo. sxc/Ogt-null mutants lacked O-linked GlcNAcylation and failed to maintain Polycomb transcriptional repression even though Polycomb group protein complexes were bound at their target sites. Polycomb repression appears to be a critical function of Sxc/Ogt in Drosophila and may be mediated by the glycosylation of Polyhomeotic.