CHARACTERIZATION OF A HOST PROTEIN ASSOCIATED WITH BROME MOSAIC-VIRUS RNA-DEPENDENT RNA-POLYMERASE
CHARACTERIZATION OF A HOST PROTEIN ASSOCIATED WITH BROME MOSAIC-VIRUS RNA-DEPENDENT RNA-POLYMERASE
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DOI：
10.1073/pnas.90.4.1498
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发表时间：
1993-02-15
影响因子：
11.1
通讯作者：
AHLQUIST, P
中科院分区：
文献类型：
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作者：
QUADT, R;KAO, CC;AHLQUIST, P
已经报道了许多（+）链RNA病毒的宿主蛋白与病毒RNA复制蛋白的缔合。然而，很少有人知道的身份或功能，这些宿主蛋白在病毒复制。在本文中，我们报告的特性与RNA依赖的RNA聚合酶（RdRp）从雀麦花叶病毒（BMV）感染大麦的主机蛋白。通过几个纯化步骤特异性地和成比例地富集BMV RdRp活性的宿主蛋白。这种RdRp相关的宿主蛋白与针对小麦胚芽真核翻译起始因子3（eIF-3）制备的抗血清反应。RdRp相关的宿主蛋白，小麦胚芽eIF-3的p41亚基，和兔网织红细胞裂解物的抗原相关蛋白都被发现以高亲和力和特异性结合BMV编码的蛋白2a，这是参与病毒RNA复制。此外，将小麦胚eIF-3或小麦胚p41亚基添加到BMV RdRp中，在体外对（-）-链RNA合成产生特异性和可重复性的3倍刺激。这些结果表明，大麦类似物eIF-3亚基p41，或密切相关的蛋白质，与BMV RdRp在体内，并参与BMV RNA复制。这一观察结果和翻译因子在噬菌体Qbeta RdRp中的既定作用表明，与翻译因子的结合可能是（+）链RNA病毒RNA复制的一般特征。
The association of host proteins with viral RNA replication proteins has been reported for a number of (+)-strand RNA viruses. However, little is known about the identity or function of these host proteins in viral replication. In this paper we report the characterization of a host protein associated with the RNA-dependent RNA polymerase (RdRp) from brome mosaic virus (BMV)-infected barley. A host protein was specifically and proportionally enriched with BMV RdRp activity through several purification steps. This RdRp-associated host protein reacted with an antiserum prepared against wheat germ eukaryotic translation initiation factor 3 (eIF-3). The RdRp-associated host protein, the p41 subunit of wheat germ eIF-3, and an antigenically related protein from rabbit reticulocyte lysates were all found to bind with high affinity and specificity to BMV-encoded protein 2a, which is involved in viral RNA replication. Moreover, addition of wheat germ eIF-3 or the p41 subunit from wheat germ to BMV RdRp gave a specific and reproducible 3-fold stimulation of (-)-strand RNA synthesis in vitro. These results suggest that the barley analog of eIF-3 subunit p41, or a closely related protein, associates with BMV RdRp in vivo and is involved in BMV RNA replication. This observation and the established role of translation factors in bacteriophage Qbeta RdRp suggest that association with translation factors may be a general feature of RNA replication by (+)-strand RNA viruses.