Conformational changes in the nuclear lamina induced by herpes simplex virus type 1 require genes UL31 and UL34
Conformational changes in the nuclear lamina induced by herpes simplex virus type 1 require genes UL31 and UL34
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DOI：
10.1128/jvi.78.11.5564-5575.2004
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发表时间：
2004-06-01
影响因子：
5.4
通讯作者：
Baines, JD
中科院分区：
文献类型：
--
作者：
Reynolds, AE;Liang, L;Baines, JD
d单纯疱疹病毒1型（HSV-1）U（L）31和U（L）34蛋白相互依赖，以适当靶向核膜，并且是核衣壳在内核膜处有效包裹所需的。在这项工作中，我们表明，而核纤层蛋白A和C（核纤层蛋白A/C）的溶解度没有显着增加，HSV诱导感染细胞的核纤层的构象变化，与三种不同的核纤层蛋白A/C-特异性抗体染色后观察。在一种情况下，在HSV感染的细胞中，与识别核纤层蛋白尾部结构域中的表位的单克隆抗体的反应性大大降低。这种明显的HSV诱导的表位掩蔽需要U（L）31和U（L）34，但这些蛋白不足以掩蔽未感染细胞中的表位，表明还需要其他HSV蛋白。在第二种情况下，用主要识别核纤层蛋白A/C杆结构域中的表位的兔多克隆抗体染色显示，U（L）34是HSV诱导的与抗体反应的表位可用性降低所必需的，而U（L）31蛋白则是这种作用的抑制剂。另一种多克隆抗体表明，在感染细胞与未感染细胞中，核纤层蛋白A/C染色几乎没有差异，表明HSV诱导的变化比核边缘核纤层蛋白耗竭的结果更具构象性。支持核纤层与U（L）31/U（L）34蛋白复合物之间相互作用的进一步证据包括以下观察结果：（i）未感染细胞中U（L）31蛋白的过表达足以将核纤层蛋白A/C从核边缘重新定位到核质聚集体中，（ii）U（L）34的过表达足以将一些核纤层蛋白A/C重新定位到细胞质中，U（L）31和U（L）34在体外均能与核纤层蛋白A/C直接结合。这些研究表明，U（L）31和U（L）34蛋白可能通过与核纤层蛋白A/C直接相互作用来改变感染细胞中核纤层的构象，并且其他蛋白也可能参与其中。考虑到核纤层潜在地将核衣壳从内核膜的包埋位点排除，纤层改变可能反映了U（L）31/U（L）34蛋白复合物在扰动纤层以促进核衣壳从核中排出中的作用。或者，该数据与纤层在将U（L）31/U（L）34蛋白复合物靶向核膜中的作用一致。
dThe herpes simplex virus type 1 (HSV-1) U(L)31 and U(L)34 proteins are dependent on each other for proper targeting to the nuclear membrane and are required for efficient envelopment of nucleocapsids at the inner nuclear membrane. In this work, we show that whereas the solubility of lamins A and C (lamin A/C) was not markedly increased, HSV induced conformational changes in the nuclear lamina of infected cells, as viewed after staining with three different lamin A/C-specitic antibodies. In one case, reactivity with a monoclonal antibody that recognizes an epitope in the lamin tail domain was greatly reduced in HSV-infected cells. This apparent HSV-induced epitope masking required both U(L)31 and U(L)34, but these proteins were not sufficient to mask the epitope in uninfected cells, indicating that other HSV proteins are also required. In the second case, staining with a rabbit polyclonal antibody that primarily recognizes epitopes in the lamin A/C rod domain revealed that U(L)34 is required for HSV-induced decreased availability of epitopes for reaction with the antibody, whereas U(L)31 protein was dispensable for this effect. Still another polyclonal antibody indicated virtually no difference in lamin A/C staining in infected versus uninfected cells, indicating that the HSV-induced changes are more conformational than the result of lamin depletion at the nuclear rim. Further evidence supporting an interaction between the nuclear lamina and the U(L)31/U(L)34 protein complex includes the observations that (i) overexpression of the U(L)31 protein in uninfected cells was sufficient to relocalize lamin A/C from the nuclear rim into nucleoplasmic aggregates, (ii) overexpression of U(L)34 was sufficient to relocalize some lamin A/C into the cytoplasm, and (iii) both U(L)31 and U(L)34 could directly bind lamin A/C in vitro. These studies suggest that the U(L)31 and U(L)34 proteins modify the conformation of the nuclear lamina in infected cells, possibly by direct interaction with lamin A/C, and that other proteins are also likely involved. Given that the nuclear lamina potentially excludes nucleocapsids from envelopment sites at the inner nuclear membrane, the lamina alteration may reflect a role of the U(L)31/U(L)34 protein complex in perturbing the lamina to promote nucleocapsid egress from the nucleus. Alternatively, the data are compatible with a role of the lamina in targeting the U(L)31/U(L)34 protein complex to the nuclear membrane.