Construction and Characterization of a Synthetic Baculovirus-inducible 39K Promoter

Abstract

The low expression activity and specificity of natural promoters limit the 22 applications of genetic engineering. To construct a highly efficient synthetic inducible 23 promoter in the Bombyx mori (Lepidoptera), we analyzed the regulatory elements and 24 functional regions of the B. mori nucleopolyhedrovirus (BmNPV) 39K promoter. The 25 results of truncated mutation analysis of the 39K promoter showed that the 26 transcriptional regulatory region spanning positions -573 to -274 and +1 to +62 is 27 essential for virus-inducible promoter activity. Further investigation using 28 electrophoretic mobility shift assay (EMSA) revealed that the baculovirus IE-1 29 protein binds to the 39K promoter at the -310 to -355 region, and transcription 30 activates the expression of 39K promoter assay. Finally, we successfully constructed a 31 synthetic inducible promoter that increase the virus-inducing activity of other 32 promoters using the baculovirus-inducible transcriptional activation region that binds 33 to specific core elements of 39K (i.e., spanning the region -310 to -355) . In summary, 34 we describes a novel, synthetic, and highly efficient biological tool, namely, a 35 virus-inducible 39K promoter, which provides endless possibilities for future gene 36 function research, gene therapy, and pest control in genetic engineering.37 38