Interactions of viral protein 3CD and poly(rC) binding protein with the 5′ untranslated region of the poliovirus genome
Interactions of viral protein 3CD and poly(rC) binding protein with the 5′ untranslated region of the poliovirus genome
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DOI：
10.1128/jvi.74.5.2219-2226.2000
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发表时间：
2000-03-01
影响因子：
5.4
通讯作者：
Andino, R
中科院分区：
文献类型：
--
作者：
Gamarnik, AV;Andino, R
聚（rC）结合蛋白（PCBP）是脊髓灰质炎病毒复制所需的细胞蛋白。PCBP与脊髓灰质炎病毒5'非翻译区（5'UTR）的两个结构域（5'三叶草结构和内部核糖体进入位点（IRES）的茎环IV）特异性相互作用。使用足迹分析和定点诱变，我们已经映射的RNA结合位点的茎环IV结构域内的细胞蛋白。在这个大结构域顶部的环中的富含C的序列是PCBP结合所需的，并且对于病毒翻译至关重要。PCBP与茎环IV RNA的结合亲和力是5'三叶草结构的6倍。然而，病毒蛋白3CD（病毒蛋白酶3C和病毒聚合酶3D的前体）与三叶草RNA的结合显著增加了PCBP对该RNA元件的亲和力。病毒蛋白3CD与苜蓿叶RNA结合，但不直接与茎环IV相互作用，也不与病毒IRES的其他RNA元件相互作用。我们的结果表明，PCBP与脊髓灰质炎病毒5 'UTR的相互作用受病毒蛋白3CD调节。
The poly(rC) binding protein (PCBP) is a cellular protein required for poliovirus replication. PCBP specifically interacts with two domains of the poliovirus 5' untranslated region (5'UTR), the 5' cloverleaf structure, and the stem-loop IV of the internal ribosome entry site (IRES). Using footprinting analysis and site-directed mutagenesis, we have mapped the RNA binding site for this cellular protein within the stem-loop IV domain. A C-rich sequence in a loop at the top of this large domain is required for PCBP binding and is crucial for viral translation. PCBP binds to stem-loop IV RNA with six-times-higher affinity than to the 5' cloverleaf structure. However, the binding of the viral protein 3CD (precursor of the viral protease 3C and the viral polymerase 3D) to the cloverleaf RNA dramatically increases the affinity of PCBP for this RNA element. The viral protein 3CD binds to the cloverleaf RNA but does not interact directly with stem-loop IV nor with other RNA elements of the viral IRES, Our results indicate that the interactions of PCBP with the poliovirus 5'UTR are modulated by the viral protein 3CD.