Relationship of Glyoxylate Shunt & Acetyl - CoA Synthetase Regulation

Loyola University Of Chicago, Chicago IL

Investigators

Abstract

Cells must sense their metabolic status as a barometer of their nutritional environment and use that information to alter their physiological programming. A prime example is the metabolic switch associated with the production and utilization of acetate undergone by cells of the bacterium Escherichia coli as they transit from exponential growth to stationary phase. During growth on certain sugars and amino acids, E. coli cells produce and excrete acetate. Once they exhaust these nutrients, they undergo a metabolic switch: instead of excreting acetate, they utilize it. This switch occurs because cells induce production of an enzyme called acetyl-CoA synthetase (Acs). This enzyme converts the previously excreted acetate to acetyl-CoA, the fundamental source of energy and the primary building block for constructing cellular components. The control of Acs production depends primarily on interactions between a complex biological machine called RNA polymerase and sequences of DNA located in front of the gene that encodes Acs. These interactions appear to be unusually elaborate. By exploring the dynamics of these interactions, this project will help us to learn how cells regulate the production of enzymes such as Acs that control critical metabolic checkpoints.