C‐terminal truncation of the transcriptional activator encoded by areA in Aspergillus nidulans results in both loss‐of‐function and gain‐of‐function phenotypes

Abstract

Mutations truncating as many as 143 C-terminal residues from the transcriptional activator encoded by the areA gene, mediating nitrogen metabolite repression in Aspergillus nidulans, do not significantly reduce the ability of the areA product to activate expression of most genes under areA control. Such mutations can even have a gain-of-function, derepressed phenotype, consistent with a critical role for this region in modulating the activity of the areA protein. However, expression of a few genes under areA control is substantially impaired by such C-terminal truncations, indicating that regions of an activator protein can play differing roles in the control of different structural genes. This underlines the advantages of being able to monitor effects of areA mutations on expression of large numbers of structural genes. Additionally, it is shown that truncation of as many as 153 C-terminal residues, virtually all amino acids C-terminal to the DNA-binding region, is compatible with retention of some areA function.

Alternative splicing and genetic diversity of the white collar-1 (wc-1) gene in cereal Phaeosphaeria pathogens

“…However, the significance of 25 amino acid residues carboxyterminal to the Znf domain of the AREA protein, which mediated nitrogen metabolite repression in Aspergillus nidulans, in gene expressions was reported (Stankovich et al 1993). Mutations in this region would result in enhancing, de-repressing and impairing various gene expressions (Stankovich et al 1993). The amino acid substitutions in particular motifs of the carboxy-terminal of transcription factor Pdr3p in yeast (Saccharomyces cerevisiae) also was reported to affect gene activations and induce multidrug resistance (Nourani et al 1997).…”

“…One possibility was that all 6 wc-1 protein isoforms might confer only one function, which was to activate the downstream frq gene. However, the significance of 25 amino acid residues carboxyterminal to the Znf domain of the AREA protein, which mediated nitrogen metabolite repression in Aspergillus nidulans, in gene expressions was reported (Stankovich et al 1993). Mutations in this region would result in enhancing, de-repressing and impairing various gene expressions (Stankovich et al 1993).…”

The Molecular Genetics of Nitrate Assimilation in Fungi and Plants

“…The two forms of regulation, induction and nitrogen metabolite repression, are largely independent of each other. Both forms of regulation affect mRNA levels (30, 73,85,129,170,187). An essential feature of methodology in elucidating forms of regulation is use of a neutral nitrogen source, i.e.…”

Efficient gene disruption in the koji -mold Aspergillus sojae using a novel variation of the positive-negative method

“…It functions as a negative regulator in the presence of nitrogen but as a positive regulator under nitrogen-repressive conditions. Disruption of the NmrA-binding region in the C-terminal region of the AreA protein resulted in derepression of gene expression under the control of AreA in A. nidulans (Stankovich et al 1993;Platt et al 1996aPlatt et al , 1996b. The wild-type strain was able to grow on CZ plates containing both KClO 3 and 100 mM sodium mono-methylammonium because niaD expression is repressed by sodium mono-methylammonium.…”