Heterogeneity in protein expression induces metabolic variability in a modeled Escherichia coli population

Piyush Labhsetwar, John Andrew Cole, Elijah Roberts, Nathan D. Price, Zaida A. Luthey-Schulten

Research output: Contribution to journalArticlepeer-review

64 Scopus citations


Stochastic gene expression can lead to phenotypic differences among cells even in isogenic populations growing under macroscopically identical conditions. Here, we apply flux balance analysis in investigating the effects of single-cell proteomics data on the metabolic behavior of an in silico Escherichia coli population. We use the latest metabolic reconstruction integrated with transcriptional regulatory data to model realistic cells growing in a glucose minimal medium under aerobic conditions. The modeled population exhibits a broad distribution of growth rates, and principal component analysis was used to identify well-defined subpopulations that differ in terms of their pathway use. The cells differentiate into slow-growing acetate-secreting cells and fast-growing CO2-secreting cells, and a large population growing at intermediate rates shift from glycolysis to Entner-Doudoroff pathway use. Constraints imposed by integrating regulatory data have a large impact on NADH oxidizing pathway use within the cell. Finally, we find that stochasticity in the expression of only a few genes may be sufficient to capture most of the metabolic variability of the entire population.

Original languageEnglish (US)
Pages (from-to)14006-14011
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number34
StatePublished - 2013
Externally publishedYes


  • Aerobic regulation
  • Metabolism
  • Pathway utilization
  • Protein noise
  • Systems biology

ASJC Scopus subject areas

  • General


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