Genetic regulation of fluxes: iron homeostasis of Escherichia coli.
Iron is an essential trace-element for most organisms. However, because high concentration of free intracellular iron is cytotoxic, cells have developed complex regulatory networks that keep free intracellular iron concentration at optimal range, allowing the incorporation of the metal into iron-using enzymes and minimizing damage to the cell. We built a mathematical model of the network that controls iron uptake and usage in the bacterium Escherichia coli to explore the dynamics of iron flow. We simulate the effect of sudden decrease or increase in the extracellular iron level on intracellular iron distribution. Based on the results of simulations we discuss the possible roles of the small RNA RyhB and the Fe-S cluster assembly systems in the optimal redistribution of iron flows. We suggest that Fe-S cluster assembly is crucial to prevent the accumulation of toxic levels of free intracellular iron when the environment suddenly becomes iron rich.
Semsey
Szabolcs
S
Center for Models of Life, Niels Bohr Institute, Copenhagen, Denmark.
Andersson
Anna M C
AM
Krishna
Sandeep
S
Jensen
Mogens Høgh
MH
Massé
Eric
E
Sneppen
Kim
K
D001692:Biological Transport; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006706:Homeostasis; D007501:Iron / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000378:metabolism; D007700:Kinetics; D008954:Models, Biological; D049490:Systems Biology
D029968:Escherichia coli Proteins; D007506:Iron-Sulfur Proteins; D007501:Iron