Fujiki Masaaki, Kaczmarczyk Jon F, Yusibov Vidadi, Rabindran Shailaja
Fraunhofer USA Center for Molecular Biotechnology, 9 Innovation Way, Suite 200, Newark, DE 19711, USA.
Virology. 2008 Nov 10;381(1):136-42. doi: 10.1016/j.virol.2008.08.022. Epub 2008 Sep 20.
We have developed a Cucumber mosaic virus (CMV)-based expression vector for the production of heterologous proteins in plants. Cell-to-cell movement of CMV is dependent on the presence of coat protein (CP). Previous studies have shown that deletion of 33 amino acids (aa) from the carboxy-terminus of the 3a movement protein facilitates cell-to-cell movement that is independent of CP. The CMV-based expression vector that we have designed utilizes this truncated 3a protein, allowing the expression of target genes from the strong CP subgenomic promoter and without the need for providing CP in trans for cell-to-cell spread. Using this vector we achieved expression levels of ~450 mg/kg leaf tissue of green fluorescent protein (GFP) when the vector was delivered into Nicotiana benthamiana plants by agroinfiltration. Human growth hormone (hGH), on the other hand, accumulated to ~170 mg/kg of leaf tissue when the same approach was used to deliver the vector.
我们开发了一种基于黄瓜花叶病毒（CMV）的表达载体，用于在植物中生产异源蛋白。CMV的细胞间移动依赖于外壳蛋白（CP）的存在。先前的研究表明，从3a移动蛋白的羧基末端缺失33个氨基酸（aa）可促进不依赖CP的细胞间移动。我们设计的基于CMV的表达载体利用了这种截短的3a蛋白，允许从强大的CP亚基因组启动子表达靶基因，并且无需通过反式提供CP来进行细胞间传播。当通过农杆菌浸润将该载体导入本氏烟草植物时，使用该载体我们实现了绿色荧光蛋白（GFP）在叶组织中的表达水平约为450 mg/kg。另一方面，当使用相同方法递送载体时，人生长激素（hGH）在叶组织中的积累量约为170 mg/kg。
