IDENTIFICATION, CLONING AND ANALYSIS OF THE ASPERGILLUS-NIGER GENE PACC, A WIDE DOMAIN REGULATORY GENE RESPONSIVE TO AMBIENT PH

A wide domain regulatory gene implicated in modulating gene expression in response to ambient pH has been cloned and sequenced from the indu strially useful filamentous fungus Aspergillus niger. This gene, pacC, is able to restore a pacC(+) phenotype to A. nidulans pacC(c)11 and p acC(c)14 mutants with respect to extent of conidiation, conidial pigme nt intensity and acid phosphatase regulation. The pacC gene of A. nige r comprises three exons, encodes a three-zinc-finger protein of 677 am ino acids, and shows pH-dependent regulation of expression: mRNA level s are elevated under alkaline conditions and considerably reduced unde r acidic conditions. The occurrence of PacC consensus binding targets within the sequences upstream of pacC may indicate autoregulation.