Institute of Apicultural Research of Chinese Academy of Agricultural Sciences made a methodological innovation in the use of exogenously expressed secretory proteins in insect cells recently, and successfully prepared a highly expressed and pure plant pattern recognition receptor-like protein BAK1, so as to optimize exogenously expressed proteins in commercially available insect cells. Relevant technologies were granted the national invention patent (patent No. ZL201811280276.4).

The baculovirus expression vector system (BEVS) has advantages in expressing exogenous recombinant proteins, improving the stability and yield of recombinant proteins, and posttranslational modification, becoming a favorable tool to express exogenous recombinant proteins. In recent years, researchers have continuously explored new technologies and applications in optimizing the insect cell expression system, in order to increase the expression of secretory proteins. According to the findings, the selection and use of signal peptides enhanced the secretion and expression abilities of recombinant proteins in insect cells. For example, signal peptides gp67 and hemolin were added to increase the expression of recombinant proteins, but those from other sources were not found to enhance the yield of recombinant proteins significantly.

In the study, signal peptides of BAK1 protein itself were found to increase the protein expression from none and improve the yield of secretory recombinant proteins significantly, with great significance for structural and functional studies of BAK1 protein and a reference value for optimizing insect cell expression systems of the same type of proteins.