Deletion of the 389 N-Terminal Residues of the Transcriptional Activator AREA Does Not Result in Nitrogen Metabolite Derepression in Aspergillus nidulans

Utilizing a homologous gene replacement in order to retain the native promoter and 5′ and 3′ untranslated messenger regions (and thereby ensure physiological validity), we have shown that deletion of the N-terminal 389 amino acids of the transcriptional activator AREA does not result in nitrogen metabolite derepression in Aspergillus nidulans. Our results provide no evidence for a modulating interaction involving the N terminus of AREA and contrast with those of H. K. Lamb, A. L. Dodds, D. R. Swatman, E. Cairns, and A. R. Hawkins (J. Bacteriol. 179:6649–6656, 1997), who used nontargeted ectopic copies of a construct containing a heterologous promoter and untranslated regions. Results obtained with this deletion mutant, nevertheless, provide further evidence for the dispensability of large portions of AREA.