Department of Biotechnology, Vienna Institute of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria.
Bioengineered. 2013 Jul-Aug;4(4):258-61. doi: 10.4161/bioe.24060. Epub 2013 Jul 2.
Designing appropriate expression vectors is one of the critical steps in the generation of stable cell lines for recombinant protein production. Conventional expression vectors are severely affected by the chromatin environment surrounding their integration site into the host genome, resulting in low expression levels and transgene silencing. In the past, a new generation of expression vectors and different strategies was developed to overcome the chromatin effects. Bacterial artificial chromosomes (BACs) are cloning vectors capable of accommodating up to 350 Kb. Thus, BACs can carry a whole eukaryotic locus with all the elements controlling the expression of a gene; therefore, BACs harbor their own chromatin environment. Expression vectors based on BACs containing open/permissive chromatin loci are not affected by the chromatin surrounding their integration site in the host cell genome. Consequently, BAC-based expression vectors containing the appropriate loci confer predictable and high levels of expression over time. These properties make BAC-based expression vectors a very attractive tool applied to the recombinant protein production field.
设计合适的表达载体是生产重组蛋白的稳定细胞系的关键步骤之一。传统的表达载体严重受到整合到宿主基因组的整合位点周围染色质环境的影响，导致表达水平低和转基因沉默。过去，开发了新一代的表达载体和不同的策略来克服染色质效应。细菌人工染色体 (BAC) 是能够容纳多达 350 Kb 的克隆载体。因此，BAC 可以携带带有所有控制基因表达的元件的整个真核基因座；因此，BAC 具有自己的染色质环境。基于 BAC 的表达载体包含开放/允许的染色质位点，不受其在宿主细胞基因组中整合位点周围染色质的影响。因此，基于 BAC 的表达载体包含适当的基因座，随着时间的推移可提供可预测和高水平的表达。这些特性使基于 BAC 的表达载体成为应用于重组蛋白生产领域的极具吸引力的工具。
