Fig. 1From: Development of an auto-inducible expression system by nitrogen sources switching based on the nitrogen catabolite repression regulationMetabolic regulation of NO3− and NH4+ in A. nidulans. The expressions of niiA and niaD are activated by the cooperation of transcription factors NirA and AreA (red arrow), while this process is repressed by NH4+ activated NmrA and PniiA/PniaD compete for AreA (blue arrow)Back to article page