寡糖糖转移酶参与了针对ER相关降解的向
Marina Shenkman1,2, Navit Ogen-Shtern1, Chaitanya Patel1,2
1The Shmunis School of Biomedicine and Cancer Research, Cell Biology Division, George Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
Cells
|October 28, 2025
概括
精糖转移酶 (OST) 复合物,以蛋白质糖化而闻名,也有助于ER相关降解 (ERAD). OST子单元与ERAD机械相互作用,促进了错误折叠的蛋白质的去除.
科学领域:
- 细胞生物学 细胞生物学
- 蛋白质生物化学 蛋白质生物化学
- 分子生物学分子生物学
背景情况:
- 对于大多数分泌和膜蛋白来说,N-糖化是关键的翻译后修饰,由内细胞网膜 (ER) 中的寡糖糖转移酶 (OST) 复合体催化.
- 在ER中失败质量控制的蛋白质是通过ER相关降解 (ERAD) 或ER-phagy降解的降解目标.
- 之前的研究表明,OST子单元在糖基化中的作用超出了它们的催化功能.
研究的目的:
- 调查OST子单元在错误折叠蛋白质的ER相关降解 (ERAD) 中的潜在参与.
- 阐明OST可能参与ERAD途径的机制.
主要方法:
- 稳定同位素标记由氨基酸在细胞培养 (SILAC) 蛋白质组学来识别蛋白质相互作用体.
- 对OST子单元表达的实验操纵 (过度表达和淘汰).
- 测试用于监测各种错误折叠蛋白质的ERAD (I/II型膜蛋白和可溶性糖蛋白).
- 分子动力学模拟.分子动力学模拟.
主要成果:
- 在蛋白质体抑制过程中,OST子单元被确定为与错误折叠的ER蛋白的关键相互作用体.
- 调节OST亚单元水平 (过度表达或淘汰) 对糖化和非糖化蛋白质的ERAD效率产生了重大影响,而这与糖化水平无关.
- 发现OST子单元与E3结合酶HRD1相互作用,并促进ERAD的逆转移步骤.
- 分子动力学模拟表明,OST跨膜域可能会稀释ER膜,可能有助于逆转移.
结论:
- OST复合体在ER中起着意想不到的双重作用,不仅参与N-糖化,还通过ERAD参与错误折叠蛋白质的质量控制和降解.
- OST子单元参与ERAD的后期阶段,与HRD1相互作用,并可能通过膜扭曲促进蛋白质逆转移.
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