Modeling partitioning of Min proteins between daughter cells after septation in Escherichia coli.
Ongoing sub-cellular oscillation of Min proteins is required to block minicelling in Escherichia coli. Experimentally, Min oscillations are seen in newly divided cells and no minicells are produced. In model Min systems many daughter cells do not oscillate following septation because of unequal partitioning of Min proteins between the daughter cells. Using the 3D model of Huang et al, we investigate the septation process in detail to determine the cause of the asymmetric partitioning of Min proteins between daughter cells. We find that this partitioning problem arises at certain phases of the MinD and MinE oscillations with respect to septal closure and it persists independently of parameter variation. At most 85% of the daughter cells exhibit Min oscillation following septation. Enhanced MinD binding at the static polar and dynamic septal regions, consistent with cardiolipin domains, does not substantially increase this fraction of oscillating daughters. We believe that this problem will be shared among all existing Min models and discuss possible biological mechanisms that may minimize partitioning errors of Min proteins following septation.
Sengupta
Supratim
S
Department of Physics & Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 3J5, Canada. sengupta@mail.jnu.ac.in
Rutenberg
Andrew
A
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D004926:Escherichia coli / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D008954:Models, Biological; D011485:Protein Binding; D011487:Protein Conformation; D013269:Stochastic Processes
D018797:Cell Cycle Proteins; D029968:Escherichia coli Proteins; C093548:MinE protein, E coli; D000251:Adenosine Triphosphatases; C072069:MinD protein, E coli