Abstract
Microbes survive in a variety of nutrient environments by modulating their intracellular metabolism. Balanced growth requires coordinated uptake of carbon and nitrogen, the primary substrates for biomass production. Yet the mechanisms that balance carbon and nitrogen uptake are poorly understood. We find in Escherichia coli that a sudden increase in nitrogen availability results in an almost immediate increase in glucose uptake. The concentrations of glycolytic intermediates and known regulators, however, remain homeostatic. Instead, we find that ±-ketoglutarate, which accumulates in nitrogen limitation, directly blocks glucose uptake by inhibiting enzyme I, the first step of the sugarĝ€"phosphoenolpyruvate phosphotransferase system (PTS). This inhibition enables rapid modulation of glycolytic flux without marked changes in the concentrations of glycolytic intermediates by simultaneously altering import of glucose and consumption of the terminal glycolytic intermediate phosphoenolpyruvate. Quantitative modeling shows that this previously unidentified regulatory connection is, in principle, sufficient to coordinate carbon and nitrogen utilization.
Original language | English (US) |
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Pages (from-to) | 894-901 |
Number of pages | 8 |
Journal | Nature Chemical Biology |
Volume | 7 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2011 |
Funding
The authors thank J. Yuan, whose experiments laid the groundwork for the current study; D. Yan for providing the GOGAT strain; and G. Gosset for providing the W3110 and VH33 strains. This research was funded by US National Science Foundation CAREER award MCB-0643859, joint Department of Energy–Air Force Office of Scientific Research Award DOE DE-SC0002077–AFOSR FA9550-09-1-0580, and the US National Institutes of Health Center for Quantitative Biology Award P50 GM071508.
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology