O-Linked N-Acetylglucosamine (O-GicNAc) Transferase and O-GicNAcase Interact with Mi2β Protein at the Aγ-Globin Promoter
O-Linked N-Acetylglucosamine (O-GicNAc) Transferase and O-GicNAcase Interact with Mi2β Protein at the Aγ-Globin Promoter
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DOI：
10.1074/jbc.m116.721928
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发表时间：
2016-07-22
影响因子：
4.8
通讯作者：
Slawson, Chad
中科院分区：
文献类型：
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作者：
Zhang, Zhen;Costa, Flavia C.;Slawson, Chad
γ-珠蛋白基因沉默的一种模式涉及结合到相对于（A）γ-珠蛋白基因帽位点的-566加塔位点的加塔-1. FOG-1. Mi2 β阻遏物复合物。然而，该阻遏物复合物如何在566加塔位点组装的机制尚不清楚。在这项研究中，我们证明了O-连接的N-乙酰葡糖胺（O-GleNAc）加工酶，O-GlcNAc-转移酶（OGT）和O-GlcNAcase（OGA），在566加塔阻遏位点与（A）γ-珠蛋白启动子相互作用;然而，加塔位点突变为GAGA显著降低β-珠蛋白基因座酵母人工染色体（（3-YAC）骨髓细胞中OGT和OGA启动子的相互作用。当用OGA抑制剂Thiamet-G处理WT（1-YAC）骨髓细胞时，（A）γ-珠蛋白启动子处的OGT、OGA和Mi2 β的占据率增加。此外，当β-珠蛋白在受孕后E18天人β-YAC转基因小鼠胎肝中受到抑制时，在（A）γ-珠蛋白启动子处OGT和Mi2 β募集增加。此外，我们发现Mi2 β被O-GlcNAc修饰，OGT和OGA都与Mi2 β、加塔-1和FOG-1相互作用。综上所述，我们的数据表明，O-GlcNAc酰化是一种新的γ-珠蛋白基因调控机制，通过调节启动子内566位加塔基序处的加塔-1-FOG-1.Mi2 β阻遏物复合物的组装来介导。
One mode of gamma-globin gene silencing involves a GATA-1.FOG-1.Mi2 beta repressor complex that binds to the - 566 GATA site relative to the (A)gamma-globin gene cap site, However, the mechanism of how this repressor complex is assembled at the 566 GATA site is unknown. In this study, we demonstrate that the O-linked N-acetylglucosamine (O-GleNAc) processing enzymes, O-GlcNAc-transferase (OGT) and O-GIcNAcase (OGA), interact with the (A)gamma-globin promoter at the 566 GATA repressor site; however, mutation of the GATA site to GAGA significantly reduces OGT and OGA promoter interactions in /3-globin locus yeast artificial chromosome ((3-YAC) bone marrow cells. When WT (1-YAC bone marrow cells are treated with the OGA inhibitor Thiamet-G, the occupancy of OGT, OGA, and Mi2 beta at the (A)gamma-globin promoter is increased. In addition, OGT and Mi2 beta recruitment is increased at the (A)gamma-globin promoter when beta-globin becomes repressed in postconception day E18 human beta-YAC transgenic mouse fetal liver. Furthermore, we show that Mi2 beta is modified with O-GlcNAc, and both OGT and OGA interact with Mi2 beta, GATA-1, and FOG-1. Taken together, our data suggest that O-GlcNAcylation is a novel mechanism of gamma-globin gene regulation mediated by modulating the assembly of the GATA-1-FOG-1.Mi2 beta repressor complex at the 566 GATA motif within the promoter.