Arg82 kinase activity and IP4 and/or IP5 are important for PHO5 transcription and chromatin remodeling. (A) Pathway for the synthesis of soluble inositol polyphosphates (13, 14). (B) Northern analysis or (C) Cla I restriction enzyme accessibility assay of pho81δ pho80tswild-type (WT) and arg82D131A pho81δ pho80ts strains grown under repressing (25°C) or shifted to inducing (37°C) conditions for 1 hour. PHO5 and PHO84 mRNA amounts in the arg82D131A strain were reduced fivefold and 1.6-fold under inducing conditions. % cut indicates the amount of accessible fragment divided by the sum of accessible and protected fragments. A schematic model of the PHO5 promoter region is shown (bottom), indicating the nucleosomes that are perturbed during induction as open circles, the Pho4 and Pho2 binding sites as dark ovals, the TATA box as an open square, and the Cla I site. (D) Northern analysis of pho81δ pho80ts strains with the relevant genotypes indicated. PHO5 and PHO84 mRNA amounts in the plc1, arg82, ipk1, and kcs1 mutants were 6% and 77%, 4% and 76%, 61% and 64%, and 45% and 50%, respectively, of the wild-type amount under inducing conditions. See fig. S1 for methods.