Regulation of the basal and cyclic AMP-stimulated rates of glycogen synthesis in [formula omitted] by an intermediate of purine biosynthesis

Abstract

In Escherichia coli an abrupt increase in the rate of glycogen synthesis occurs at the onset of total nitrogen starvation. We present here both in vivo and in vitro data indicating that this increase occurs because of the loss of a nitrogen-containing intermediate of purine biosynthesis (apparently 5-aminoimidazole-4-carboxamide ribonucleotide) that inhibits glycogen synthesis. We also show that this inhibitory intermediate antagonizes the stimulation of glycogen synthesis by 3′,5′-cyclic AMP. The uncovering of the regulation of glycogen synthesis by this inhibitor apparently provides the first link in understanding the 23-year-old observation of a reciprocal relationship between growth rate and glycogen accumulation in E. coli .