TY - JOUR
T1 - Systems-level analysis of mechanisms regulating yeast metabolic flux
AU - Hackett, Sean R.
AU - Zanotelli, Vito R.T.
AU - Xu, Wenxin
AU - Goya, Jonathan
AU - Park, Junyoung O.
AU - Perlman, David H.
AU - Gibney, Patrick A.
AU - Botstein, David
AU - Storey, John D.
AU - Rabinowitz, Joshua D.
N1 - Publisher Copyright:
Copyright 2016 by the American Association for the Advancement of Science; all rights reserved.
PY - 2016/10/28
Y1 - 2016/10/28
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84992709113&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84992709113&partnerID=8YFLogxK
U2 - 10.1126/science.aaf2786
DO - 10.1126/science.aaf2786
M3 - Article
C2 - 27789812
AN - SCOPUS:84992709113
SN - 0036-8075
VL - 354
JO - Science
JF - Science
IS - 6311
M1 - aaf2786
ER -