Optimization of the expression of the HIV fusion inhibitor cyanovirin-N from the tobacco plastid genome
Optimization of the expression of the HIV fusion inhibitor cyanovirin-N from the tobacco plastid genome
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DOI：
10.1111/j.1467-7652.2011.00598.x
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发表时间：
2011-06-01
影响因子：
13.8
通讯作者：
Bock, Ralph
中科院分区：
文献类型：
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作者：
Elghabi, Zouhair;Karcher, Daniel;Bock, Ralph
具有转基因质体（叶绿体）基因组的植物代表了分子农业中有前途的生产平台，主要是因为质体具有将外源蛋白积累到非常高水平的潜力，并且质体遗传的母系模式赋予了增加的生物安全性。虽然一些转基因可以表达到非常高的水平，但其他转基因的表达一直不成功。缺乏可检测的转基因表达通常归因于RNA不稳定性或蛋白质不稳定性。在这里，我们研究了提高一种难以在叶绿体中表达的药物蛋白质产量的可能性：HIV-1融合抑制剂cyanovirin-N（CV-N）。测试各种N-末端和C-末端融合肽序列从两种蛋白质已知积累到高水平的转基因质体（绿色荧光蛋白和蛋白质抗生素PlyGBS），我们表明，低mRNA的稳定性和低蛋白质的稳定性有助于缺乏可检测的CV-N在叶绿体中的表达。这两个问题都可以通过N-末端融合到CV-N编码区来缓解，从而突出了优化质体转基因表达的合适策略。
P>Plants with transgenic plastid (chloroplast) genomes represent a promising production platform in molecular farming, mainly because of the plastids' potential to accumulate foreign proteins to very high levels and the increased biosafety conferred by the maternal mode of plastid inheritance. Although some transgenes can be expressed to extraordinarily high levels, the expression of others has been unsuccessful. Lack of detectable transgene expression is usually attributable to either RNA instability or protein instability. Here, we have investigated the possibilities to improve the production of a pharmaceutical protein that is difficult to express in chloroplasts: the HIV-1 fusion inhibitor cyanovirin-N (CV-N). Testing various N-terminal and C-terminal fusions to peptide sequences from two proteins known to accumulate to high levels in transgenic plastids (GFP and the protein antibiotic PlyGBS), we show that both low mRNA stability and low protein stability contribute to the lack of detectable CV-N expression in chloroplasts. Both problems can be alleviated by N-terminal fusions to the CV-N coding region, thus highlighting a suitable strategy for optimization of plastid transgene expression.