Antisense Silencing of the creA Gene in Aspergillus nidulans

Abstract

Antisense expression of a portion of the gene encoding the major carbon catabolite repressor CREA in Aspergillus nidulans resulted in a substantial increase in the levels of glucose-repressible enzymes, both endogenous and heterologous, in the presence of glucose. The derepression effect was approximately one-half of that achieved in a null creA mutant. Unlike results for that mutant, however, growth parameters and colony morphology in the antisense transformants were not affected.

Silencing of the Aspergillopepsin B ( pepB ) Gene of Aspergillus awamori by Antisense RNA Expression or Protease Removal by Gene Disruption Results in a Large Increase in Thaumatin Production

“…6C). Expression of the antisense pepB led to a reduction in the presence of aspergillopepsin B ranging from 10% in transformant asX4 to 70% in transformant asH5, values similar to those obtained in Aspergillus with other antisense strategies (6,24,31,40). However, the small increment in the increase of thaumatin production observed after antisense RNA formation indicated that the remaining aspergillopepsin B still degraded thaumatin; therefore, it was necessary to disrupt the pepB gene in the thaumatin-producing strain TB2b1-44-pyrG45 to remove completely aspergillopepsin B from culture broths.…”

“…Although the technique is simple, the effectiveness of the method is influenced by many factors (1). This technique has been successfully used to silence the creA gene in Aspergillus nidulans (6). It was, therefore, of interest to try to silence the pepB gene in A. awamori by the antisense RNA technique, as a first approach to elimination of the negative effect of the presence of aspergillopepsin B on thaumatin accumulation.…”

Transcription analysis using high-density micro-arrays of Aspergillus nidulans wild-type and creA mutant during growth on glucose or ethanol

“…Even though the growth conditions/parameters are easier to control in chemostat-fermentations, it has been shown by Bautista et al (2000) and Ilyés et al (2004) that the repressing eVect of glucose for a recombinant amylase, an endogenous endoarabinase, and beta-galactosidase activity is dependent on the speciWc growth rate in glucose limited chemostat-fermentations. The lower dilution rate, the more de-repressed these enzymes are in the reference strain whereas the de-repressing eVect observed in the creA mutant is unaVected by the dilution rate.…”

Protein Kinase C (PkcA) of Aspergillus nidulans Is Involved in Penicillin Production

“…The production of pkcA antisense RNA was an alternative way to study the function of PkcA, which was further investigated in this study because it showed the highest degree of similarity to typical fungal Pkc's. Antisense RNA was successfully applied to filamentous fungi in a number of recent studies (7,23,53). As shown here, a good level of pkcA antisense RNA was obtained by using the promoter region of the alcA gene of A. nidulans when transformant strains were grown with lactose as the carbon source plus cyclopentanone.…”