The regulation of aryl sulphatase in Aspergillus nidulans

Abstract

The aryl sulphatase of Aspergillus nidulans is derepressed in a medium that contains low amounts of inorganic sulphate or sulphur-containing amino acids. Isotopic labelling experiments show that the enzyme molecules are made de novo. However, once derepressed, the formation of the enzyme becomes progressively insensitive to cycloheximide. It is suggested that active sulphatase is made in two steps, one sensitive to cycloheximide and the other insensitive. Both of these steps appear to be regulated by sulphur metabolites.