Mutual effects of MinD-membrane interaction: I. Changes in the membrane properties induced by MinD binding

Biochim Biophys Acta. 2008 Nov;1778(11):2496-504. doi: 10.1016/j.bbamem.2008.08.003. Epub 2008 Aug 12.

Abstract

In Escherichia coli and other bacteria, MinD, along with MinE and MinC, rapidly oscillates from one pole of the cell to the other controlling the correct placement of the division septum. MinD binds to the membrane through its amphipathic C-terminal alpha-helix. This binding, promoted by ATP-induced dimerization, may be further enhanced by a consequent attraction of acidic phospholipids and formation of a stable proteolipid domain. In the context of this hypothesis we studied changes in dynamics of a model membrane caused by MinD binding using membrane-embedded fluorescent probes as reporters. A remarkable increase in membrane viscosity and order upon MinD binding to acidic phospholipids was evident from the pyrene and DPH fluorescence changes. This viscosity increase is cooperative with regards to the concentration of MinD-ATP, but not of the ADP form, indicative of dimerization. Moreover, similar changes in the membrane dynamics were demonstrated in the native inverted cytoplasmic membranes of E. coli, with a different depth effect. The mobility of pyrene-labeled phosphatidylglycerol indicated formation of acidic phospholipid-enriched domains in a mixed acidic-zwitterionic membrane at specific MinD/phospholipid ratios. A comparison between MinD from E. coli and Neisseria gonorrhea is also presented.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism*
  • Adenosine Triphosphatases / pharmacology
  • Adenosine Triphosphate / metabolism
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism*
  • Diffusion / drug effects
  • Escherichia coli / cytology
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / metabolism*
  • Escherichia coli Proteins / pharmacology
  • Fluorescence Polarization
  • Liposomes / metabolism
  • Phospholipids / metabolism
  • Protein Binding / drug effects
  • Pyrenes / pharmacology

Substances

  • Escherichia coli Proteins
  • Liposomes
  • Phospholipids
  • Pyrenes
  • Adenosine Triphosphate
  • pyrene
  • Adenosine Triphosphatases
  • MinD protein, E coli