Characterization of the Aspergillus parasiticus major nitrogen regulatory gene, areA

The major nitrogen regulatory gene, areA, was cloned from Aspergillus paras iticus. It encoded a polypeptide of 864 amino acids which contained a nucle ar localization signal (NLS), a highly acidic region from positions 497 to 542, a Cys-X-2-Cys-X-17-Cys-X-2-Cys DNA-binding motif and a conserved carbo xy-terminus. Electrophoretic mobility shift assays suggested that the A. pa rasiticus AREA DNA-binding domain fusion protein bound cooperatively to sin gle GATA elements in the A. parasiticus niaD-niiA intergenic region. AREA a lso bound to the aflR-qflJ intergenic region of the aflatoxin biosynthesis gene cluster. Regions of areA were fused to a yeast GAL4 DNA-binding domain coding region to localize putative transcription activation domain(s) of A REA based on activation of the GAL1(p)::lacZ reporter gene expression. The portion between NLS and the acidic domain demonstrated 16-20-fold higher ac tivation activities than other portions of AREA, which suggests that the tr anscription activation domain is located in this region. (C) 2000 Elsevier Science B.V. All rights reserved.