A Novel DNA Motif Contributes to Selective Replication of a Geminivirus-Associated Betasatellite by a Helper Virus-Encoded Replication-Related Protein
A Novel DNA Motif Contributes to Selective Replication of a Geminivirus-Associated Betasatellite by a Helper Virus-Encoded Replication-Related Protein
复制标题
一种新的 DNA 基序有助于通过辅助病毒编码的复制相关蛋白选择性复制双子病毒相关的 β 卫星
DOI：
10.1128/jvi.02290-15
复制
发表时间：
2015-12
影响因子：
5.4
通讯作者：
Zhou Xueping
中科院分区：
文献类型：
--
作者：
Zhang Tong;Xu Xiongbiao;Huang Changjun;Qian Yajuan;Li Zhenghe;Zhou Xueping
摘要 植物双生病毒单链基因组的滚环复制是由病毒复制相关蛋白 (Rep) 与其在复制起点的同源基因组的序列特异性 DNA 结合启动的。单分贝戈莫病毒相关的β卫星可以通过同源和一些非同源辅助病毒进行反式复制，但β卫星复制混杂的分子基础仍然未知。早期研究表明，当番茄黄曲叶病毒（TYLCCCNV）或烟草卷芽病毒（TbCSV）与同源和非同源β卫星共接种时，在感染后期同源β卫星比非同源β卫星占主导地位。在本研究中，我们在番茄黄叶卷曲中国β卫星和烟草卷叶β卫星之间构建了互反嵌合β卫星，并在与TYLCCCNV或TbCSV共接种到植物上时测定了它们与野生型β卫星的竞争力。我们绘制了紧邻β卫星起源的保守滚环十字形结构上游的区域，该区域赋予同源Rep介导的复制优势而不是非同源卫星。 DNase I 保护和体外结合测定进一步鉴定了一种称为 Rep 结合基序 (RBM) 的新序列元件，它特异性结合同源 Rep 蛋白和非同源 Rep，尽管亲和力较低。此外，我们发现 RBM-Rep 结合亲和力与原生质体中的 β 卫星复制效率相关。我们的数据表明，尽管不存在 Rep 介导的复制的严格特异性，但 β 卫星已适应其同源 Rep，以便在共同进化过程中进行有效复制。重要性 Begomovirus 是众多环状 DNA 病毒，可在全世界范围内引起农作物的毁灭性疾病。单部分贝戈莫病毒经常与β卫星相关，β卫星对于诱导典型疾病症状至关重要。两种不同的β卫星与一种辅助病毒共存在自然界中是罕见的。我们之前的研究表明，begomoviruses 可以将同源 β 卫星复制到比非同源 β 卫星更高的水平。然而，β卫星选择性复制的分子机制仍然很大程度上未知。我们研究了 Begomovirus 复制相关蛋白和 β 卫星 DNA 之间的相互作用。我们发现复制相关蛋白特异性结合β卫星中的基序，对同源基序的亲和力高于对非同源基序的亲和力。这种对同源基序结合的偏好决定了β卫星的选择性复制。我们还证明该基序对于β卫星复制至关重要。这些发现为辅助双生病毒对β卫星的混杂但选择性复制提供了新的线索。
ABSTRACT Rolling-circle replication of single-stranded genomes of plant geminiviruses is initiated by sequence-specific DNA binding of the viral replication-related protein (Rep) to its cognate genome at the replication origin. Monopartite begomovirus-associated betasatellites can be trans replicated by both cognate and some noncognate helper viruses, but the molecular basis of replication promiscuity of betasatellites remains uncharacterized. Earlier studies showed that when tomato yellow leaf curl China virus (TYLCCNV) or tobacco curly shoot virus (TbCSV) is coinoculated with both cognate and noncognate betasatellites, the cognate betasatellite dominates over the noncognate one at the late stages of infection. In this study, we constructed reciprocal chimeric betasatellites between tomato yellow leaf curl China betasatellite and tobacco curly shoot betasatellite and assayed their competitiveness against wild-type betasatellite when coinoculated with TYLCCNV or TbCSV onto plants. We mapped a region immediately upstream of the conserved rolling-circle cruciform structure of betasatellite origin that confers the cognate Rep-mediated replication advantage over the noncognate satellite. DNase I protection and in vitro binding assays further identified a novel sequence element termed Rep-binding motif (RBM), which specifically binds to the cognate Rep protein and to the noncognate Rep, albeit at lower affinity. Furthermore, we showed that RBM-Rep binding affinity is correlated with betasatellite replication efficiency in protoplasts. Our data suggest that although strict specificity of Rep-mediated replication does not exist, betasatellites have adapted to their cognate Reps for efficient replication during coevolution. IMPORTANCE Begomoviruses are numerous circular DNA viruses that cause devastating diseases of crops worldwide. Monopartite begomoviruses are frequently associated with betasatellites which are essential for induction of typical disease symptoms. Coexistence of two distinct betasatellites with one helper virus is rare in nature. Our previous research showed that begomoviruses can trans replicate cognate betasatellites to higher levels than noncognate ones. However, the molecular mechanisms of betasatellites selective replication remain largely unknown. We investigated the interaction between the begomovirus replication-associated protein and betasatellite DNA. We found that the replication-associated protein specifically binds to a motif in betasatellites, with higher affinity for the cognate motif than the noncognate motif. This preference for cognate motif binding determines the selective replication of betasatellites. We also demonstrated that this motif is essential for betasatellite replication. These findings shed new light on the promiscuous yet selective replication of betasatellites by helper geminiviruses.
登录
查看更多内容
影响因子：
5.4
作者：
Cui, XF;Tao, XR;Zhou, XP
通讯作者：
Zhou, XP
影响因子：
3.3
作者：
J. Stanley
通讯作者：
J. Stanley
影响因子：
64.8
作者：
Saunders, K;Bedford, ID;Stanley, J
通讯作者：
Stanley, J
影响因子：
2.7
作者：
A. Varsani;bullet J Jesú;Navas-Castillo bullet;E. Moriones;C. Hernández-Zepeda;bullet Ali;Idris bullet-I
通讯作者：
A. Varsani;bullet J Jesú;Navas-Castillo bullet;E. Moriones;C. Hernández-Zepeda;bullet Ali;Idris bullet-I
影响因子：
10.5
作者：
Yang, Jun-Yi;Iwasaki, Mayumi;Chua, Nam-Hai
通讯作者：
Chua, Nam-Hai