Evidence of the Involvement of O-GlcNAc-modified Human RNA Polymerase II CTD in Transcription in Vitro and in Vivo
Evidence of the Involvement of O-GlcNAc-modified Human RNA Polymerase II CTD in Transcription in Vitro and in Vivo
复制标题
DOI：
10.1074/jbc.m111.330910
复制
发表时间：
2012-07-06
影响因子：
4.8
通讯作者：
Lewis, Brian A.
中科院分区：
文献类型：
--
作者：
Ranuncolo, Stella M.;Ghosh, Salil;Lewis, Brian A.
RNA 聚合酶 II C 末端结构域 (CTD) 作为招募参与转录的机制的支架，在翻译后进行修饰。尽管 RNA 聚合酶 II CTD 的 O-GlcNAc 修饰已于 1993 年被记录，但其功能意义仍然不清楚。我们发现 O-GlcNAc 转移酶 (OGT) 修饰了 CTD 丝氨酸残基 5 和 7。OGT 和 OGA（N-乙酰氨基葡萄糖苷酶）的药物抑制会在起始复合物组装过程中阻断转录。聚合酶 II 和 OGT 进行免疫共沉淀，OGT 是预引发复合物的组成部分。 OGT shRNA 实验表明，OGT 的减少会导致几个 B 细胞启动子的转录和 RNA 聚合酶 II 占用量减少。这些数据表明，O-GlcNAc 在聚合酶 II 上的开启和关闭循环发生在预引发复合物的组装过程中。我们的结果定义了 CTD 和 O-GlcNAc 在高等真核生物转录起始调节中的意想不到的作用。
The RNA polymerase II C-terminal domain (CTD), which serves as a scaffold to recruit machinery involved in transcription, is modified post-translationally. Although the O-GlcNAc modification of RNA polymerase II CTD was documented in 1993, its functional significance remained obscure. We show that O-GlcNAc transferase (OGT) modified CTD serine residues 5 and 7. Drug inhibition of OGT and OGA (N-acetylglucosaminidase) blocked transcription during preinitiation complex assembly. Polymerase II and OGT co-immunoprecipitated, and OGT is a component of the preinitiation complex. OGT shRNA experiments showed that reduction of OGT causes a reduction in transcription and RNA polymerase II occupancy at several B-cell promoters. These data suggest that the cycling of O-GlcNAc on and off of polymerase II occurs during assembly of the preinitiation complex. Our results define unexpected roles for both the CTD and O-GlcNAc in the regulation of transcription initiation in higher eukaryotes.