English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  The polyhedrin gene promoter has an essential role in regulating foreign gene expression in baculovirus expression vector systems (BEVS); however, the high-level transcription mechanism is still unknown. One-hybrid screening in yeast is a powerful way of identifying rapidly heterologous transcription factors that can interact with the polyhedrin promoter DNA sequence. In the current study, total RNA was extracted from the fat bodies of fifth-instar silkworm larvae that had been infected with  Bombyx mori  nuclear polyhedrosis virus (BmNPV) for 5 days; complementary DNA (cDNA) was then generated using reverse-transcription (RT)-PCR to construct a silkworm gene expression library. Key polyhedrin promoter bait sequences were synthesized to generate a bait yeast strain, which was used to screen the one-hybrid cDNA library.    Results  In total, 12 positive yeast colonies were obtained from the SD/-Leu/AbA plates; sequencing analysis showed that they belong to two different protein cDNA colonies. Positive colonies underwent bioinformatics analysis, which revealed one colony to be ribosomal proteins [ B. mori  ribosomal protein SA (BmRPSA)] and the other to be NPV DNA-binding proteins (DBP). To further verify the regulatory function of these two protein groups, transient expression vectors (pSK-IE- dbp  and pSK-IE- BmRPSA ) were constructed. The recombinant plasmids were then transfected into cultured  B. mori  N (BmN) cells, which had been infected with a recombinant bacmid containing the gene encoding luciferase ( luc ). The results showed that overexpression of either  dbp  or  BmRPSA  upregulated the  polh  promoter-driven transcription of  luc  in BmN cells. In addition,  dbp  or  BmRPSA  RNA interference (RNAi) resulted in the downregulation of luciferase reporter expression in BmN cells, demonstrating that DBP and BmRPSA are important for  luc  transcription. EMSA results further confirmed that DBP could directly bind to the conserved single-stranded  polh  promoter region  in intro . However, EMSA assay also showed that BmRPSA did not bind to this region, precluding a direct DNA association.    Conclusions  Both DBP and BmRPSA are important for  polh  transcription. DBP can regulate  polh  promoter activity by direct binding to the conserved single-stranded  polh  promoter region, BmRPSA may regulate  polh  promoter activity by indirect binding to this region.

The screening and functional study of proteins binding with the BmNPV polyhedrin promoter