Regulation of Nitrate Reduction in Aspergillus nidulans

Regulation of Intracellular and Extracellular Neutral and Alkaline Proteases in Aspergillus nidulans

“…The mutant xprDr is insensitive to ammonium repression of protease and has been described previously (Cohen, 1972); its other defects in ammonium regulation were described by Pateman et al (1973). Recent results indicate that the xprDI recombinants in current use may carry an unidentified chromo-Growth in preparation for phosphorus-starvation was carried out in liquid minimal medium containing a growth-limiting concentration (0.05 mM) of potassium dihydrogen phosphate; effective phosphorus starvation could not be obtained in a transfer experiment if the phosphorus concentration during growth was higher.…”

“…When growing on media containing protein as sole nitrogen source, three extracellular proteases (a, 7-6, and e) are released into the medium and occur in the mycelium together with protease / 3 in its active form. This regulation of proteases by nitrogen metabolites has been called 'ammonium repression' (Cohen, 1972(Cohen, , 1973Pateman, Kinghorn, Dunn & Forbes, 1973).…”

NAD and NADP L-Glutamate Dehydrogenase Activity and Ammonium Regulation in Aspergillus nidulans

“…DER3 is one of a series of ammonium derepressed mutants obtained by J. A. Pateman selecting directly for ammonium derepression of nitrate reductase using a replica plating technique similar to that described by Pateman & Cove (1967). anzrAr was obtained by J.…”

“…Mutations in a number of loci in Aspergilks nidulans can affect the regulation of a number of systems by ammonium. These systems include nitrate reductase (Pateman & Cove, 1967), hypoxanthine dehydrogenase (Scazzocchio & Darlington, I 968), extracellular protease (Cohen, I 972), acetamidase and formamidase (Hynes & Pateman,197oa,b), glutamate uptake (Kinghorn & Pateman, 1972;Pateman & Kinghorn, unpublished) and urea uptake (Dunn & Pateman, 1972). Arst & Cove (1969) found that mutation in two loci meaA and meaB resulted in resistance to methylamine and derepression for many ammonium repressed systems.…”

Mutant analysis, a key tool for the study of metabolism and development

“…Two of the genes which can mutate to affect nitrate assimilation, nirA and areA, are concerned with its regulation. The nirA gene codes for a pathway-specific regulator mediating the nitrate induction of nitrate and nitrite reductase (Pateman and Cove, 1967;Pateman et a/., 1967). The areA gene product is a multipathway regulator which is required for the expression of a number of genes which are subject to repression in the presence of ammonium (Arst and Cove, 1973).…”