TY - JOUR
T1 - Changes in the cellular energy state affect the activity of
the bacterial phosphotransferase system
AU - Rohwer, J.M.
AU - Jensen, Peter Ruhdal
AU - Shinohara, Y.
AU - Postma, P.W.
AU - Westerhoff, H.V.
PY - 1996
Y1 - 1996
N2 - The effect of different cellular free-energy states on the uptake of methyl α-D-glucopyranoside, an analogue of glucose, by the Escherichia coli phosphoenolpyruvate:carbohydrate phosphotransferase system was investigated. The intracellular [ATP]/[ADP] ratio was varied by changing the expression of the atp operon, which codes for the H+-ATPase, or by adding an uncoupler of oxidative phosphorylation or an inhibitor of respiration. Corresponding initial phosphotransferase uptake rates were determined using an improved uptake assay that works with growing cells in steady state. The results show that the initial uptake rate was decreased under conditions of lowered intracellular [ATP]/[ADP] ratios, irrespective of which method was used to change the cellular energy state. When either the expression of the atp operon was changed or 2,4-dinitrophenol was added to wild-type cells, the relationship between initial phosphotransferase uptake rate and the logarithm of the [ATP]/[ADP] ratio was approximately linear. These results suggest that the cellular free-energy state, as reflected in the intracellular [ATP]/[ADP] ratio, plays an important role in regulating the activity of the phosphotransferase system.
AB - The effect of different cellular free-energy states on the uptake of methyl α-D-glucopyranoside, an analogue of glucose, by the Escherichia coli phosphoenolpyruvate:carbohydrate phosphotransferase system was investigated. The intracellular [ATP]/[ADP] ratio was varied by changing the expression of the atp operon, which codes for the H+-ATPase, or by adding an uncoupler of oxidative phosphorylation or an inhibitor of respiration. Corresponding initial phosphotransferase uptake rates were determined using an improved uptake assay that works with growing cells in steady state. The results show that the initial uptake rate was decreased under conditions of lowered intracellular [ATP]/[ADP] ratios, irrespective of which method was used to change the cellular energy state. When either the expression of the atp operon was changed or 2,4-dinitrophenol was added to wild-type cells, the relationship between initial phosphotransferase uptake rate and the logarithm of the [ATP]/[ADP] ratio was approximately linear. These results suggest that the cellular free-energy state, as reflected in the intracellular [ATP]/[ADP] ratio, plays an important role in regulating the activity of the phosphotransferase system.
U2 - 10.1111/j.1432-1033.1996.00225.x
DO - 10.1111/j.1432-1033.1996.00225.x
M3 - Journal article
SN - 0014-2956
VL - 235
SP - 225
EP - 230
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
IS - 1-2
ER -