Superior expression of juvenile hormone esterase and beta-galactosidase from the basic protein promoter of Autographa californica nuclear polyhedrosis virus compared to the p10 protein and polyhedrin promoters.

The expression characteristics of the p10, polyhedrin and basic protein promoters of Autographa californica nuclear polyhedrosis virus were compared using two reporter enzymes, juvenile hormone esterase (JHE) and beta-galactosidase. In these systems, JHE is exported from the cell and beta-galactosidase is localized to the cytosol. Expression of JHE from the basic, p10 and polyhedrin promoters was first detected in the medium at 13, 19 and 27 h post-infection respectively. The basic protein promoter yielded the highest expression of the three promoters tested for both enzymes, as determined by protein and enzyme activity assays. In addition, yields of beta-galactosidase and JHE under control of the p10 promoter are higher relative to expression under control of the polyhedrin promoter. These data highlight the importance of investigation of viral promoters other than the polyhedrin promoter for high yield protein expression in vitro, and for insecticidal use of recombinant baculoviruses requiring high levels of expression. The results support revision of the current concept that very late viral promoters are always optimal for high yield recombinant protein expression.