Inositol polyphosphate kinase activity of Arg82/ArgRIII is not required for the regulation of the arginine metabolism in yeast

Arg82, a nuclear regulator of diverse cellular processes in yeast, is an in ositol polyphosphate kinase. Some defects such as the regulation of arginin e metabolism observed in an arg82 Delta, result from a lack of Mcm1 and Arg 80 stability. We show here that neither the kinase activity of Arg82 nor in ositol phosphates are required for the control of arginine metabolism Arg82 mutations keeping kinase active affect the expression of arginine genes, w hereas mutations in the kinase domain do not impair this metabolic control. (C) 2000 Federation of European Biochemical Societies. Published by Elsevi er Science B.V. All rights reserved.