Overcoming Barriers to Protein Production in Plant Cell Cultures

本项目的目的是确定从转基因植物细胞悬浮液中生产外源蛋白的瓶颈，并制定遗传策略来克服这些限制。将研究三种模型蛋白。这些包括乙型肝炎表面抗原、诺瓦克病毒衣壳蛋白和人分泌碱性磷酸酶。这些蛋白质将在两种寄主系统中进行研究，即烟草和大豆悬浮培养。主要研究者（pi）将验证一个假设，即由于与内源性mRNA在翻译机制上的竞争，转录mRNA在指数/平稳期后期比指数成长期有更多的翻译机会。如果这是真的，那么在指数增长后期/平稳阶段的诱导表达可能会导致更高的产品水平。

The objective of this project is to identify bottlenecks in heterologous protein production from transgenic plant cell suspensions, and to develop genetic strategies to overcome these limitations. Three model proteins will be studied. These include, hepatitis B surface antigen, Norwalk virus capsid protein, and human secreted alkaline phosphatase. These proteins will be studied in two host systems, i. e. tobacco and soybean suspension cultures. The Principal Investigators (PIs) will test the hypothesis that transcribed mRNA may have increased opportunities for translation in the late exponential/stationary phase as compared with the exponential growth phase due to competition with endogenous mRNA for translational machinery. If this is true, then inducible expression during the late exponential growth/stationary phase might lead to higher product levels.