展开的蛋白质是Ire1-激活连接体,直接诱导展开的蛋白质反应
Brooke M Gardner1, Peter Walter
1Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
概括
展开的蛋白质反应 (UPR) 被激活时,内细胞网膜 (ER) 蛋白 Ire1 直接与展开的蛋白质结合. 这种由特定的氨基酸残留物介导的结合触发了Ire1的寡合化和UPR的激活.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 展开的蛋白质反应 (UPR) 是一种细胞应激反应,对于维持内 плазма网膜 (ER) 恒常状态至关重要.
- 跨膜蛋白Ire1是ER压力的关键传感器,通过寡合并激活其细胞质域来启动UPR.
- 通过Ire1检测ER压力的精确机制仍然不完全理解.
研究的目的:
- 研究酵母Ire1蛋白质对ER应激检测的分子基础.
- 通过Ire1.1.识别的展开蛋白质的特定特征.
- 阐明直接蛋白-未折叠蛋白相互作用在UPR激活中的作用.
主要方法:
- 利用酵母模型在体内研究IRE1的功能.
- 使用净化的酵母Ire1核心光内域 (cLD) 进行了体外结合试验.
- 通过使用各种氨基酸成分来表征结合特异性.
- 在Ire1 cLD的假定结槽中引入突变,以评估结合和寡合化.
主要成果:
- 酵母Ire1的核心光域 (cLD) 直接与酵母细胞内的未折叠蛋白质结合.
- Ire1 cLD在体外表现出与富含基和疏水性残留物的优先结合.
- 在Ire1 cLD的假定结槽中的突变显著损害了结合.
- 的结合Ire1cLD诱导其在体外的寡合化.
结论:
- 展开蛋白质与Ire1 cLD的直接结合是检测ER压力的主要机制.
- 在Ire1 cLD上的结合隙内,特定的氨基酸残留物介导着未折叠蛋白质的识别.
- 这种直接的相互作用和随后的Ire1的寡合化对于启动未折叠蛋白质反应至关重要.
相关概念视频
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ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...

