Chattopadhyay D, Banerjee A K
Department of Molecular Biology, Cleveland Clinic Foundation, OH 44106.
Proc Natl Acad Sci U S A. 1988 Nov;85(21):7977-81. doi: 10.1073/pnas.85.21.7977.
The phosphoprotein (NS) of vesicular stomatitis virus is an indispensable subunit of the virion-associated RNA polymerase (L). NS consists of a highly acidic NH2-terminal domain and a basic COOH-terminal domain. Unlike the latter, the amino acid sequences of the NH2-terminal regions are highly dissimilar among different viral serotypes, although they share structural similarities. We have cloned an NS gene into the SP6 transcription vector and replaced the 5'-terminal 80% by a full-length gene for beta-tubulin, which contains an acidic COOH-terminal domain. Here we present evidence that the chimeric tubulin-NS protein is biologically active and that the acidic region in tubulin directly affects the transcription reaction. These observations indicate that NS probably functions as an activator protein in which the acidic domain stimulates transcription of the viral genes by interacting with the RNA polymerase as observed for eukaryotic cellular transcription activators.
水疱性口炎病毒的磷蛋白（NS）是病毒体相关RNA聚合酶（L）不可或缺的亚基。NS由一个高度酸性的NH2末端结构域和一个碱性的COOH末端结构域组成。与后者不同的是，尽管不同病毒血清型的NH2末端区域氨基酸序列具有结构相似性，但它们之间差异很大。我们已将NS基因克隆到SP6转录载体中，并用含有酸性COOH末端结构域的β-微管蛋白全长基因替换了5'-末端的80%。在此我们提供证据表明，嵌合的微管蛋白-NS蛋白具有生物活性，并且微管蛋白中的酸性区域直接影响转录反应。这些观察结果表明，NS可能作为一种激活蛋白发挥作用，其中酸性结构域通过与RNA聚合酶相互作用刺激病毒基因的转录，这与真核细胞转录激活因子的情况类似。
