Effect of gpd box copy numbers in the gpdA promoter of Aspergillus nidulans on its transcription efficiency in Aspergillus niger

FEMS Microbiol Lett. 2018 Aug 1;365(15). doi: 10.1093/femsle/fny154.

Abstract

In this study, we characterised PgpdA, PgpdA2B, PgpdA3B and PgpdA4B promoters, containing 1-4 copies of gpd box by modifying the gpdA promoter, and constructed pSZHGX-xynB expression vectors, which were introduced into Aspergillus niger CICC2462 through Agrobacterium-mediated transformation. Thus, An (PgpdA-xynB), An (PgpdA2B-xynB), An (PgpdA3B-xynB) and An (PgpdA4B-xynB) homozygous recombinant strains were obtained. The xylanase activity of homozygous recombinant strains was measured. The enzymatic activities of An (PgpdA-xynB), An (PgpdA2B-xynB), An (PgpdA3B-xynB) and An (PgpdA4B-xynB) peaked on the 7th day of fermentation, at 1578.67, 2333.88, 3588.38 and 3183.51 U·mL-1, respectively. SDS-PAGE and qRT-PCR analysis indicated that An (PgpdA3B-xynB), containing three copies of gpd box, demonstrated the highest levels of protein expression and transcription. These results suggested that the PgpdA3B promoter promotes highly efficient transcription and may serve as a strong constitutive promoter for efficient recombinant protein expression. Additionally, a number of constitutive promoters with various transcription efficiencies were identified for the metabolic engineering of A. niger. Accordingly, this study provides a new approach for obtaining promoters with different transcription efficiencies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus nidulans / genetics*
  • Aspergillus nidulans / metabolism
  • Aspergillus niger / genetics*
  • Aspergillus niger / metabolism
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Gene Dosage
  • Gene Expression Regulation, Bacterial*
  • Promoter Regions, Genetic
  • Transcription, Genetic

Substances

  • Fungal Proteins