The carboxy-terminal fragment of nucleolin interacts with the nucleocapsid domain of retroviral Gag proteins and inhibits virion assembly
The carboxy-terminal fragment of nucleolin interacts with the nucleocapsid domain of retroviral Gag proteins and inhibits virion assembly
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DOI：
10.1128/jvi.74.23.11027-11039.2000
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发表时间：
2000-12-01
影响因子：
5.4
通讯作者：
Goff, SP
中科院分区：
文献类型：
--
作者：
Bacharach, E;Gonsky, J;Goff, SP
酵母双杂交筛选与鼠白血病病毒（MuLV）Gag蛋白相互作用的细胞蛋白，导致核仁素的鉴定，核仁素是一种已知在核糖体组装中起作用的宿主蛋白。相互作用融合体含有核仁素的羧基末端212个氨基酸（Nuc（212）]。Gag的核衣壳（NQ部分）是必要的并且足以介导与Nuc的结合（212）。Gag与Nuc（212）的相互作用可以在体外证明，并通过MuLV病毒粒子内Nuc（212）的NC依赖性掺入在体内得到证实。Nuc（212）的过表达，而非全长核仁素的过表达，有效且特异性地阻断MuLV病毒体组装和/或释放。选择MuLV的突变体以特异性破坏与Nuc的结合（212），发现其对于病毒体组装是严重缺陷的。该突变体在邻近CA-NC连接的衣壳（CA）中具有单点突变，表明该区域在Moloney MuLV组装中的作用。这些实验证明，选择结合组装结构域的蛋白质可以产生病毒体组装的有效抑制剂。这些实验也提出了核仁-Gag相互作用可能参与病毒体组装的可能性。
A yeast two-hybrid screen for cellular proteins that interact with the murine leukemia virus (MuLV) Gag protein resulted in the identification of nucleolin, a host protein known to function in ribosome assembly. The interacting fusions contained the carboxy-terminal 212 amino acids of nucleolin (Nuc(212)]. The nucleocapsid (NQ portion of Gag was necessary and sufficient to mediate the binding to Nuc(212). The interaction of Gag with Nuc(212) could be demonstrated in vitro and was manifested in vivo by the NC-dependent incorporation of Nuc(212) inside MuLV virions. Overexpression of Nuc(212), but not full-length nucleolin, potently and specifically blocked MuLV virion assembly and/or release. A mutant of MuLV, selected to specifically disrupt the binding to Nuc(212), was found to be severely defective for virion assembly. This mutant harbors a single point mutation in capsid (CA) adjacent to the CA-NC junction, suggesting a role for this region in Moloney MuLV assembly. These experiments demonstrate that selection for proteins that bind assembly domain(s) can yield potent inhibitors of virion assembly. These experiments also raise the possibility that a nucleolin-Gag interaction may be involved in virion assembly.