在APC型FurE输送器中的最后两个跨膜螺旋起作用,作为度ER-exit所必需的分子内伴侣
Yiannis Pyrris1, Georgia F Papadaki1, Emmanuel Mikros2
1Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, 15784, Greece.
Microbial cell (Graz, Austria)
|January 16, 2024
概括
菌尿酸载体Fure的C端TMS11-12作为一个分子内伴侣. 在TMS12中的特定残留物对FurE折叠,ER退出和血贩运至关重要.
科学领域:
- 生物化学 生化学
- 分子生物学分子生物学
- 菌类生物学 菌类生物学
背景情况:
- FurE是一种真菌H+共载体,参与细胞吸收尿酸,艾伦因,乌拉和核基相似物.
- FurE属于NCS1蛋白家族,在结构上与APC超级家族的载体相关,通常具有十个跨膜段 (TMS1-10).
- 在大多数APC型运输机中发现的两个额外的C端TMS段 (TMS11-12) 的功能在很大程度上是未知的.
研究的目的:
- 调查真菌载体FureE的C端TMS11-12段的作用.
- 在TMS11-12中识别特定的残留物,对FURE功能和贩运至关重要.
- 阐明 TMS11-12 影响 FurE 的 ER 出口和等离子体膜定位的机制.
主要方法:
- 在FurE中对TMS11-12进行系统突变分析.
- 分子建模用于预测TMS12残留物和其他跨膜段之间的相互作用.
- 基因分析以确认特定残留物在ER出口和贩运中的作用.
- 共同表达研究,以评估突变FURE变种对野生类型FURE贩运的影响.
主要成果:
- 在TMS12,Trp473和Tyr484中,两种芳香残留物被确定为ER出口和血贩运的关键.
- 分子建模表明Trp473和Tyr484与TMS2,TMS3,TMS10和其他TMS12残留物的动态相互作用.
- 关键残留物 (Phe111,Asp406) 和TMS12芳香残留物的突变证实了它们在Fure ER-exit中发挥的重要作用.
- 主导阴性FurE突变体 (FurE-Y484F,FurE-W473A) 的共同表达表明FurE寡合化或微域分割,以实现高效的ER退出和贩运.
- 缺少TMS11-12的截断FURE对野生类型FURE贩运没有表现出主导负面影响.
结论:
- FurE的TMS11-12区域充当分子内伴侣,对适当的蛋白质折叠至关重要.
- 这种陪同活动提供了一个结构代码,对于FURE分割成ER出口站点至关重要.
- 这些发现凸显了C终端TMS段在APC型运输机的运输和功能中的重要性.
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