Interaction of bacterial actin-like proteins with the cell membrane

• Applicant: Professor Dr. Peter Graumann
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2008 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 43311986

• Final Report Year: 2016

Final Report Abstract

Prior to the project outlined above, it had become clear that MreB interacts with several membrane proteins that are required for cell wall synthesis and for the maintenance of rod shape, in many different bacteria, including B. subtilis. Within the scope of FOR 929, we were able to show that B. subtilis MreB does not form a continuous helical structure, as was proposed in earlier work by other groups, but discontinuous extended filaments that move in varying angles around 90° and in both directions underneath the cell membrane. Most likely, entire filaments move, rather than actin-like tread milling, and filaments can coordinate the movement of cell wall synthesis enzymes across the diameter of the cell, i.e. over a distance of 1.7 µm or more, which may stabilize the formation of rod shaped cells. We have also efficiently collaborated with several other groups of the consortium, and have introduced bacterial cell biology to several groups in Freiburg, generating a powerful combination of existing expertise in biochemistry with cell biology, to better understand dynamics of proteins at and within bacterial membranes.

Publications

• (2013) Motion of variable-length MreB filaments at the bacterial cell membrane influences cell morphology. Mol. Biol. Cell 24: 2340-2349
  Reimold, Christian; Defeu Soufo, Herve Joel; Dempwolff, Felix & Graumann, Peter L.
  
• (2013) Substrate-Dependent Assembly of the Tat Translocase as Observed in Live Escherichia coli Cells. PLOS One 8:e69488
  Rose, Patrick; Fröbel, Julia; Graumann, Peter L. & Müller, Matthias
  
• (2013) Superresolution Imaging of Dynamic MreB Filaments in B. subtilis — A Multiple-Motor-Driven Transport? Biophysical Journal 105:1171-1181
  Olshausen, Philipp v.; Defeu Soufo, Hervé Joël; Wicker, Kai; Heintzmann, Rainer; Graumann, Peter L. & Rohrbach, Alexander
  
• (2014) Organization of the Escherichia coli aerobic enzyme complexes of oxidative phosphorylation in dynamic domains within the cytoplasmic membrane. Microbiologyopen 3, 316-326
  Erhardt, Heiko; Dempwolff, Felix; Pfreundschuh, Moritz; Riehle, Marc; Schäfer, Caspar; Pohl, Thomas; Graumann, Peter & Friedrich, Thorsten
  
• (2015) Translation Elongation Factor EF-Tu Modulates Filament Formation of Actin-Like MreB Protein In Vitro. J. Mol. Biol. 427:1715-1727
  Defeu Soufo, Hervé Joël; Reimold, Christian; Breddermann, Hannes; Mannherz, Hans G. & Graumann, Peter L.