在MDCK细胞中进行基底侧排序需要一个独特的细胞质域决定因子
W Hunziker1, C Harter, K Matter
1Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510.
Cell
|September 6, 1991
概括
在MDCK细胞中,膜蛋白的基底侧运输需要特定的细胞质信号,而不是默认分类. 这些信号与某些蛋白质的内细胞分裂决定因素不同,表明复杂的分类机制.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 贩运膜蛋白的人口贩运
背景情况:
- 膜蛋白的基底侧运输对于细胞极性至关重要.
- 目前的模型表明基底侧排序是某些细胞类型的默认路径.
- 已知细胞质域决定因素会影响蛋白质定位.
研究的目的:
- 调查细胞质域决定因素在MDCK细胞中膜蛋白的基底侧运输中的作用.
- 为了确定基底侧排序信号是否与内细胞分裂信号不同.
- 挑战基底侧膜蛋白质的默认分类模型.
主要方法:
- 在Madin-Darby犬 (MDCK) 细胞中研究膜蛋白传输.
- 分析特定细胞质域序列的作用,包括氨酸残留物.
- 对比不同膜蛋白的运输途径,如Fc受体,溶酶体糖蛋白Igp120和LDL受体.
主要成果:
- 在MDCK细胞中,基底侧转运不是一个默认的过程,而是取决于细胞质域的决定因素.
- 对于一些蛋白质 (Fc受体,Igp120),决定因素类似于克拉特林涂层坑内细胞.
- 对于其他蛋白质 (LDL受体),基底侧决定因素与内细胞分裂信号不同,特别是对氨酸的需求.
- 在Igp120中去除一个氨酸阻断了内部化,并将其重定向到顶端表面.
- 对于许多缺乏特定基底侧决定因子的蛋白质,顶运输发生,这表明顶信号广泛存在.
结论:
- 在MDCK细胞中,底侧运输是一个活跃的,信号依赖的过程.
- 基底侧排序的细胞质域决定因素是多样化的,并不普遍与内细胞分裂信号相关.
- 广泛分布的顶峰运输信号的存在解释了为什么蛋白质在没有底侧决定因素的情况下到达顶峰表面.
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