hycu-hr6, A large homologous region of the Hyphantria cunea nucleopolyhedrovirus genome, as a powerful and versatile enhancer in insect expression systems.
We previously identified a large homologous region (hr), hycu-hr6, in the genome of the Hyphantria cunea nucleopolyhedrovirus (HycuNPV) and suggested that hycu-hr6 was the largest baculovirus promoter enhancer hr identified so far. In this study, we examined the enhancement activity of hycu-hr6 against two promoters from constitutive baculovirus immediate early genes, the HycuNPV ie1 (hycu-ie1) and the Orgyia pseudotsugata multicapsid (M) NPV ie2 (op-ie2), and against a promoter from the inducible Drosophila heat shock protein 70 gene (hsp70) in five lepidopteran (BmN-4, Ld652Y, Sf9, SpIm, and TN368) and one dipteran (S2) insect cell lines. Comparative analyses of transient expression assays using the firefly luciferase gene (luc) as a reporter showed that hycu-hr6 enhanced the activity of all three promoters in all tested cell lines. Comparison of the enhancement efficiency of hycu-hr6 with that of Autographa californica MNPV (AcMNPV) hr5, an enhancer commonly used to improve the activity of AcMNPV ie1 promoter in many insect expression vectors, established that hycu-hr6 was a more efficient enhancer. These results indicate that hycu-hr6 is a versatile and superior promoter enhancer in several insect cell lines and favor the incorporation of hycu-hr6 into insect expression vectors to maximize promoter activity.
Felipe Alves
Cristiano A
CA
Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan.
Ishikawa
Hiroki
H
Ikeda
Motoko
M
Kobayashi
Michihiro
M
D000818:Animals; D002460:Cell Line; D004742:Enhancer Elements, Genetic; D015870:Gene Expression; D017930:Genes, Reporter; D005818:Genetic Engineering / Q000379:methods*; D007313:Insecta; D049409:Luciferases, Firefly / Q000096:biosynthesis / Q000235:genetics; D017924:Nucleopolyhedroviruses / Q000235:genetics*; D011401:Promoter Regions, Genetic
D049409:Luciferases, Firefly