Ammonium Repression of Extracellular Protease in Aspergillus nidulans

Abstract

Summary Extracellular protease of Aspergillus nidulans is repressible by ammonium. A mutant (xprDI) selected for derepression of protease in the presence of ammonium is also derepressed for nitrate reductase, xanthine dehydrogenase and glutamate uptake; it retains the ability to use ammonium as sole nitrogen source. The mutant is partially dominant in heterozygous diploids. The mutation does not confer methylamine resistance, nor are methylamine-resistant(meaA) strains derepressed for protease.