氨基酸信号链接O-GlcNAc转移酶到胰岛素抵抗
Xiaoyong Yang1, Pat P Ongusaha, Philip D Miles
1Howard Hughes Medical Institute and Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
Nature
|February 22, 2008
概括
作为对胰岛素的反应,O-GlcNAc转移酶 (OGT) 酶与细胞膜结合,从而改变胰岛素信号通路. 这种O-GlcNAc修饰有助于胰岛素抵抗和2型糖尿病.
科学领域:
- 生物化学 生物化学
- 细胞生物学 细胞生物学
- 代谢调节 代谢调节 代谢调节
背景情况:
- 六胺生物合成途径通过O-链的β-N-乙糖胺 (O-GlcNAc) 修饰来调节细胞过程.
- 这个系统充当营养传感器,将代谢状态与细胞调节联系起来.
- 修改O-GlcNAc会影响信号传导,转录和蛋白质降解.
研究的目的:
- 研究O-GlcNAc转移酶 (OGT) 在胰岛素信号传递中的作用.
- 阐明OGT修改胰岛素通路的机制.
- 了解O-GlcNAc修饰对胰岛素耐药性的贡献.
主要方法:
- 描述OGT的氨酸化物结合域.
- 在胰岛素诱导后OGT在血中招募的分析.
- 对胰岛素信号组件的O-GlcNAc修饰的评估.
- 对肝脏OGT过度表达对胰岛素敏感性和基因表达的影响的评估.
主要成果:
- OGT拥有一种新的氨酸化物结合域.
- 胰岛素通过酸丁酸3,4,5-三酸盐诱导OGT进入血膜.
- 胰岛素信号通路的O-GlcNAc修饰导致酸化变化和信号减弱.
- 肝脏OGT过度表达导致胰岛素耐药性,脂质障碍和胰岛素反应性基因表达受损.
结论:
- 营养线索通过O-GlcNAc修饰来调节胰岛素信号传递.
- 在这个法规中,OGT与酸的相互作用是关键机制.
- 异常的O-GlcNAc修饰有助于胰岛素耐药性和2型糖尿病的发病.
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