活细胞内O-GlcNAc糖基化修饰调控工具的开发和应用

葛韵 研究员

深圳湾实验室

时间：2022年10月14日（星期五）16:00

地点：化四-112教室变更为同安二106会议室

厦门大学谱学分析与仪器教育部重点实验室

2022年10月12日

报告人简介：

葛韵博士，深圳湾实验室特聘研究员。2013年本科毕业于厦门大学，2018年于北京大学化学与分子工程学院获得化学生物学博士学位，师从长江学者特聘教授陈鹏。博士期间主要从事遗传密码子拓展技术、生物正交反应和蛋白质标记工具的开发和应用，先后发展了新型蛋白质激活策略和酶介导的细胞间邻近标记反应。曾获得北京大学国家奖学金、校长奖学金、优秀毕业生等多项奖励。2018年至2021年在哈佛大学化学与化学生物学系进行博士后研究，主要集中于O-GlcNAc糖基化修饰的蛋白质组学鉴定、调控工具的开发和修饰功能的研究。博后期间发展了首个基于纳米抗体的具有蛋白选择性的靶向去糖基化工具，受到了多家媒体的报道和广泛关注。迄今为止以第一作者身份在Nature Chemical Biology, Journal of the American Chemical Society, Chemical Science等杂志上发表文章，以共同作者身份在Angewandte Chemie, ACS Central Science等杂志上合作发表论文十余篇，并申请国内外专利三项。

报告摘要：

O-linked N-acetylglucosamine (O-GlcNAc) is an essential and dynamic post-translational modification that is presented on thousands of nucleocytoplasmic proteins, serving as a nutrition sensor for environmental cues. Interrogating the role of O-GlcNAc on a single target protein and spatiotemporal regulation of O-GlcNAc are two main challenges, which are crucial yet limited due to lacking study approaches. Herein, we developed a nanobody-fused split O-GlcNAcase (OGA) as an O-GlcNAc eraser for selective deglycosylation of a target protein in cells. After systematic cellular optimization, we identified a split OGA with reduced inherent deglycosidase activity that selectively removed O-GlcNAc from the desired target protein when directed by a nanobody. We demonstrate the generality of the nanobody-fused split OGA using four nanobodies against five target proteins and use the system to study the impact of O-GlcNAc on the transcription factors c-Jun and c-Fos. Besides, we designed a small molecule mediated OGA activation approach for intracellular O-GlcNAc regulation with spatiotemporal resolution through rational protein engineering and optimization. We demonstrated that O-GlcNAc reduction by this activation approach synergistically suppressed cancer cell survival. Altogether, these strategies facilitate the precise regulation and functional understandings of O-GlcNAcylation in live cells.