DOMAINS INVOLVED IN MULTIMER ASSEMBLY OF VONWILLEBRAND-FACTOR (VWF) - MULTIMERIZATION IS INDEPENDENT OF DIMERIZATION
DOMAINS INVOLVED IN MULTIMER ASSEMBLY OF VONWILLEBRAND-FACTOR (VWF) - MULTIMERIZATION IS INDEPENDENT OF DIMERIZATION
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DOI：
10.1002/j.1460-2075.1990.tb08176.x
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发表时间：
1990-03-01
期刊：
影响因子：
11.4
通讯作者：
PANNEKOEK, H
中科院分区：
文献类型：
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作者：
VOORBERG, J;FONTIJN, R;PANNEKOEK, H
冯维勒布兰德因子 (provWF) 的前体蛋白由四个重复结构域组成，表示为 D1-D2-D''-D3-A1-A2-A3-D4-B1-B2-B3-C1-C2。结构域D1和D2构成氨基末端原多肽，其余结构域是蛋白水解加工时产生的成熟vWF。我们之前已经证明，vWF原的多肽原对于vWF原二聚体组装成多聚体是必需的，这一过程对于血小板有效粘附到受损血管壁至关重要。在这里，我们基于各个结构域之间的同源性，采用全长 vWF cDNA 构建了一系列缺失突变体。具体而言，删除结构域D''、D3或两者，并在COS-1细胞中瞬时表达后分析突变体vWF蛋白的多聚体模式。结果表明，除了原多肽外，多聚体组装还需要 D'' 和 D3 结构域。此外，通过分析仅包含紧邻多肽原的结构域D''和D3的构建体，显示这是vWF蛋白中参与多聚体组装的唯一部分。由于前 vWF 二聚体的形成依赖于成熟 vWF 的羧基末端区域，因此得出结论，多聚体组装是一个独立于二聚化的过程。
The precursor protein of von Willebrand factor (provWF) consist of four repeated domains, denoted D1-D2-D''-D3-A1-A2-A3-D4-B1-B2-B3-C1-C2. The domains D1 and D2 constitute the amino-terminal propolypeptide and remaining domains mature vWF, generated upon proteolytic processing. We have shown previously that the pro-polypeptide of pro-vWF is obligatory for assembly of pro-vWF dimers into multimers, a process vital for efficient adhesion of platelets to an injured vessel wall. Here, we have employed full length vWF cDNA to construct a series of deletion mutants, based on the homology between the various domains. Specifically, the domains D'', D3 or both were deleted and the multimeric pattern of the mutant vWF proteins was analysed after transient expression in COS-1 cells. It is demonstrated that in addition to the pro-polypeptide, both the D'' and the D3 domain are required for multimer assembly. Furthermore, by analysing a construct containing only the domains D'' and D3 next to the pro-polypeptide it is shown that this is the only part of the vWF protein involved in multimer assembly. Since, the formation of pro-vWF dimers relies on the carboxy-terminal area of mature vWF, it is concluded that multimer assembly is a process independent of dimerization.