Molecular Interactions of the Min Protein System Reproduce Spatiotemporal Patterning in Growing and Dividing Escherichia coli Cells

PLoS One. 2015 May 27;10(5):e0128148. doi: 10.1371/journal.pone.0128148. eCollection 2015.

Abstract

Oscillations of the Min protein system are involved in the correct midcell placement of the divisome during Escherichia coli cell division. Based on molecular interactions of the Min system, we formulated a mathematical model that reproduces Min patterning during cell growth and division. Specifically, the increase in the residence time of MinD attached to the membrane as its own concentration increases, is accounted for by dimerisation of membrane-bound MinD and its interaction with MinE. Simulation of this system generates unparalleled correlation between the waveshape of experimental and theoretical MinD distributions, suggesting that the dominant interactions of the physical system have been successfully incorporated into the model. For cells where MinD is fully-labelled with GFP, the model reproduces the stationary localization of MinD-GFP for short cells, followed by oscillations from pole to pole in larger cells, and the transition to the symmetric distribution during cell filamentation. Cells containing a secondary, GFP-labelled MinD display a contrasting pattern. The model is able to account for these differences, including temporary midcell localization just prior to division, by increasing the rate constant controlling MinD ATPase and heterotetramer dissociation. For both experimental conditions, the model can explain how cell division results in an equal distribution of MinD and MinE in the two daughter cells, and accounts for the temperature dependence of the period of Min oscillations. Thus, we show that while other interactions may be present, they are not needed to reproduce the main characteristics of the Min system in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Biological Phenomena / physiology
  • Cell Cycle Proteins / metabolism*
  • Cell Division / physiology*
  • Cell Membrane / metabolism
  • Cell Membrane / physiology
  • Escherichia coli / metabolism*
  • Escherichia coli / physiology
  • Escherichia coli Proteins / metabolism*
  • Green Fluorescent Proteins / metabolism
  • Membrane Proteins / metabolism
  • Models, Theoretical

Substances

  • Cell Cycle Proteins
  • Escherichia coli Proteins
  • Membrane Proteins
  • Green Fluorescent Proteins
  • Adenosine Triphosphatases

Grants and funding

JCW was the recipient of an Australian Postgraduate Award. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.