Borna disease virus matrix protein is an integral component of the viral ribonucleoprotein complex that does not interfere with polymerase activity
Borna disease virus matrix protein is an integral component of the viral ribonucleoprotein complex that does not interfere with polymerase activity
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DOI：
10.1128/jvi.01351-06
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发表时间：
2007-01-01
影响因子：
5.4
通讯作者：
Schwemmle, Martin
中科院分区：
文献类型：
--
作者：
Chase, Geoffrey;Mayer, Daniel;Schwemmle, Martin
我们最近发现，博尔纳病病毒（BDV）的基质蛋白M与亲和纯化的核蛋白（N）从BDV感染的细胞共纯化，这表明M是一个不可分割的组成部分的病毒核糖核蛋白复合物（RNP）。然而，由于缺乏适当的工具，进一步的研究受到阻碍。在这里，我们产生了M特异性兔多克隆抗血清，以调查M的细胞内分布以及其与其他病毒蛋白在BDV感染的细胞中的共定位。免疫荧光分析表明，M是位于细胞质和核点状结构典型的BDV感染。共定位研究表明，协会的M与核衣壳蛋白在这些核点状结构。原位杂交分析表明，M也与病毒基因组共定位，这意味着M协会直接与病毒RNP。生物化学研究表明，M特异性结合磷蛋白P，但不结合N。M与P的结合涉及P的N末端，并且不依赖于P寡聚化的能力。令人惊讶的是，尽管P-M复合物形成，但BDV聚合酶活性不受M抑制，而是略微升高，如在微复制子测定中所揭示的。因此，与其他负链RNA病毒的M蛋白不同，BDV-M似乎是RNP的组成部分，而不干扰病毒聚合酶活性。我们建议，这一独特的功能BDV-M是一个先决条件，建立BDV持久性。
We have recently shown that the matrix protein M of Borna disease virus (BDV) copurifies with the affinity-purified nucleoprotein (N) from BDV-infected cells, suggesting that M is an integral component of the viral ribonucleoprotein complex (RNP). However, further studies were hampered by the lack of appropriate tools. Here we generated an M-specific rabbit pollyclonal antiserum to investigate the intracellular distribution of M as well as its colocalization with other viral proteins in BDV-infected cells. Immunofluorescence analysis revealed that M is located both in the cytoplasm and in nuclear punctate structures typical for BDV infection. Collocalization studies indicated an association of M with nucleocapsid proteins in these nuclear punctate structures. In situ hybridization analysis revealed that M also collocalizes with the viral genome, implying that M associates directly with viral RNPs. Biochemical studies demonstrated that M binds specifically to the phosphoprotein P but not to N. Binding of M to P involves the N terminus of P and is independent of the ability of P to oligomerize. Surprisingly, despite P-M complex formation, BDV polymerase activity was not inhibited but rather slightly elevated by M, as revealed in a minireplicon assay. Thus, unlike M proteins of other negative-strand RNA viruses, BDV-M seems to be an integral component of the RNPs without interfering with the viral polymerase activity. We propose that this unique feature of BDV-M is a prerequisite for the establishment of BDV persistence.