Lateral diffusion of membrane-spanning and glycosylphosphatidylinositol-linked proteins: toward establishing rules governing the lateral mobility of membrane proteins.
Lateral diffusion of membrane-spanning and glycosylphosphatidylinositol-linked proteins: toward establishing rules governing the lateral mobility of membrane proteins.
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DOI：
10.1083/jcb.115.1.75
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发表时间：
1991-10
期刊：
影响因子：
--
通讯作者：
Jacobson K
中科院分区：
文献类型：
--
作者：
Zhang F;Crise B;Su B;Hou Y;Rose JK;Bothwell A;Jacobson K
在动物细胞的质膜中，许多跨膜蛋白表现出比糖基磷脂酰肌醇（GPI）连接蛋白更低的横向迁移率。为了确定GPI连接是否是这些蛋白质的高横向移动性的主要决定因素，我们测量了嵌合膜蛋白的横向扩散，所述嵌合膜蛋白由转化为GPI连接蛋白的正常跨膜蛋白或转化为跨膜蛋白的GPI连接蛋白组成。这些研究表明，GPI连接仅少量（约两倍）的几个GPI连接的蛋白质的更高的流动性。这些蛋白质的高迁移率的主要决定因素反而存在于细胞外结构域中。我们提出，缺乏这种蛋白质类的细胞外结构域与其他细胞表面成分的相互作用，允许扩散，仅受膜锚的扩散。相比之下，以水泡性口炎病毒G糖蛋白为例的跨膜蛋白的胞外域的细胞表面相互作用相对于许多GPI连接的蛋白质将其侧向扩散系数降低了近10倍。
In the plasma membrane of animal cells, many membrane-spanning proteins exhibit lower lateral mobilities than glycosylphosphatidylinositol (GPI)-linked proteins. To determine if the GPI linkage was a major determinant of the high lateral mobility of these proteins, we measured the lateral diffusion of chimeric membrane proteins composed of normally transmembrane proteins that were converted to GPI-linked proteins, or GPI-linked proteins that were converted to membrane- spanning proteins. These studies indicate that GPI linkage contributes only marginally (approximately twofold) to the higher mobility of several GPI-linked proteins. The major determinant of the high mobility of these proteins resides instead in the extracellular domain. We propose that lack of interaction of the extracellular domain of this protein class with other cell surface components allows diffusion that is constrained only by the diffusion of the membrane anchor. In contrast, cell surface interactions of the ectodomain of membrane- spanning proteins exemplified by the vesicular stomatitis virus G glycoprotein reduces their lateral diffusion coefficients by nearly 10- fold with respect to many GPI-linked proteins.