Systems-level analysis of mechanisms regulating yeast metabolic flux.

TitleSystems-level analysis of mechanisms regulating yeast metabolic flux.
Publication TypeJournal Article
Year of Publication2016
AuthorsHackett, SR, Zanotelli, VRT, Xu, W, Goya, J, Park, JO, Perlman, DH, Gibney, PA, Botstein, D, Storey, JD, Rabinowitz, JD
JournalScience
Volume354
Issue6311
Date Published2016 10 28
ISSN1095-9203
KeywordsAllosteric Regulation, Citrates, Glycolysis, Kinetics, Metabolic Networks and Pathways, Nitrogen, Pyruvate Kinase, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins
Abstract

<p>Cellular metabolic fluxes are determined by enzyme activities and metabolite abundances. Biochemical approaches reveal the impact of specific substrates or regulators on enzyme kinetics but do not capture the extent to which metabolite and enzyme concentrations vary across physiological states and, therefore, how cellular reactions are regulated. We measured enzyme and metabolite concentrations and metabolic fluxes across 25 steady-state yeast cultures. We then assessed the extent to which flux can be explained by a Michaelis-Menten relationship between enzyme, substrate, product, and potential regulator concentrations. This revealed three previously unrecognized instances of cross-pathway regulation, which we biochemically verified. One of these involved inhibition of pyruvate kinase by citrate, which accumulated and thereby curtailed glycolytic outflow in nitrogen-limited yeast. Overall, substrate concentrations were the strongest driver of the net rates of cellular metabolic reactions, with metabolite concentrations collectively having more than double the physiological impact of enzymes.</p>

DOI10.1126/science.aaf2786
Alternate JournalScience
PubMed ID27789812
PubMed Central IDPMC5414049
Grant ListR01 GM046406 / GM / NIGMS NIH HHS / United States
R01 HG002913 / HG / NHGRI NIH HHS / United States
R37 GM046406 / GM / NIGMS NIH HHS / United States
P50 GM071508 / GM / NIGMS NIH HHS / United States
P30 CA016359 / CA / NCI NIH HHS / United States
R01 CA163591 / CA / NCI NIH HHS / United States