Vaccinia virus A30L protein is required for association of viral membranes with dense viroplasm to form immature virions.
Vaccinia virus A30L protein is required for association of viral membranes with dense viroplasm to form immature virions.
复制标题
痘苗病毒 A30L 蛋白是病毒膜与致密病毒质结合形成未成熟病毒粒子所必需的。
DOI：
10.1128/jvi.75.13.5752-5761.2001
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发表时间：
2001
影响因子：
5.4
通讯作者：
Moss,B
中科院分区：
文献类型：
--
作者：
Szajner,P;Weisberg,AS;Wolffe,EJ;Moss,B
先前未表征的痘苗病毒 A30L 基因在所有脊椎动物痘病毒中都有直向同源物，但没有可识别的非痘病毒同源物或功能基序。我们确定 A30L 基因受晚期启动子调控并编码大约 9 kDa 的蛋白质。受感染细胞的免疫电镜表明，A30L 蛋白与新月形和未成熟病毒颗粒膜包围的病毒质相关。 A30L 蛋白也存在于成熟病毒颗粒中，并通过非离子去污剂和还原剂处理部分释放，与核心和包膜之间的基质中的位置一致。为了确定 A30L 蛋白的作用，我们构建了具有诱导型 A30L 基因的严格条件致死突变体。在缺乏诱导剂的情况下，病毒早期和晚期蛋白的合成发生，但某些核心蛋白的蛋白水解加工受到抑制，表明组装受阻。通过电子显微镜证实了对病毒成熟的抑制。在不允许的条件下，我们观察到异常大的、致密的、颗粒状的病毒质团，边缘清晰。病毒新月膜除了与病毒质有一定距离外，看起来正常；空的未成熟病毒颗粒；以及缺乏成熟的病毒体。数据表明，A30L 蛋白是痘苗病毒形态发生所必需的，特别是致密病毒质与病毒膜的结合。
The previously uncharacterized A30L gene of vaccinia virus has orthologs in all vertebrate poxviruses but no recognizable nonpoxvirus homologs or functional motifs. We determined that the A30L gene was regulated by a late promoter and encoded a protein of approximately 9 kDa. Immunoelectron microscopy of infected cells indicated that the A30L protein was associated with viroplasm enclosed by crescent and immature virion membranes. The A30L protein was also present in mature virions and was partially released by treatment with a nonionic detergent and reducing agent, consistent with a location in the matrix between the core and envelope. To determine the role of the A30L protein, we constructed a stringent conditional lethal mutant with an inducible A30L gene. In the absence of inducer, synthesis of viral early and late proteins occurred but the proteolytic processing of certain core proteins was inhibited, suggesting an assembly block. Inhibition of virus maturation was confirmed by electron microscopy. Under nonpermissive conditions, we observed aberrant large, dense, granular masses of viroplasm with clearly defined margins; viral crescent membranes that appeared normal except for their location at a distance from viroplasm; empty immature virions; and an absence of mature virions. The data indicated that the A30L protein is needed for vaccinia virus morphogenesis, specifically the association of the dense viroplasm with viral membranes.