Aim: In vivo regulatory features of AnRP, a repressor for the cgxA gene, were characterized.
Methods and results: Titration of AnRP by introducing multiple copies of its specific binding sequence 'TTGACAAAT' into an Aspergillus nidulans strain containing the Chaetomium gracile cgxA gene enhanced the cgxA gene expression. AnRP functions independently of and cooperatively with CreA to modulate the cgxA gene expression.
Conclusions: AnRP is a CreA-independent negative regulatory factor controlling the cgxA expression.
Significance and the impact of the study: Xylanases of filamentous fungi have received increased interest because of their potential biotechnological applications. Elucidation of the factors involved in the regulation of the xylanolytic genes in fungi will help to increase levels of xylanase production.