As scientists at the Max Planck Institute for Biochemistry and at the French INRA now show, MreB molecules assemble into larger units, but not - as previously believed – into continuous helical structures. The circular movement of these units along the inside of the bacterial envelope is mediated by cell wall synthesis, which in turn requires the support of MreB. This mutual interaction may be a widespread phenomenon among bacteria and opens up new avenues for therapeutic intervention. The bacterial cell wall is already a major target for antibiotics.
Bacillus subtilis cell with several patches of Mbl (MreB-like protein) fused to the green fluorescent protein. Colors represent overlay of images taken by total internal reflection fluorescence microscopy (TIRFM, red), epifluorescence (green) and transmitted light (blue, indicates cell outline). Picture: Roland Wedlich-Söldner / Copyright: MPI of Biochemistry
Even single cells have to maintain their shape: In higher organisms, the supporting structures of the cytoskeleton, which include filament networks made of the protein actin, take care of this job. The much smaller bacterial cells possess similar cytoskeletal structures, such as the actin related protein MreB. Up to now, scientists believed that this molecule forms spiral structures on the inside of the cell membrane in non-spherical bacteria, which serve as a scaffold for the assembly of the comparatively rigid cell wall.
Using innovative imaging technologies based as fluorescent microscopy, the scientists in the laboratory of Roland Wedlich-Söldner now have been able to show, that MreB proteins do not form such highly ordered structures – but yet are organized in more complex ways than they had previously assumed. “MreB molecules assemble into larger units, or patches. They move in circular paths along the inside of the cell membrane, but without following a preferred direction”, explains Julia Domínguez-Escobar, PhD student at the Max Planck Institute of Biochemistry.
A highly unexpected finding of the study was that the movement of MreB patches relies on a functioning cell wall. MreB structures cannot move on their own but are pulled along the bacterial envelope by the newly synthesized cell wall material. The MreB patches are located at the inside, the cell wall at the outside of the cell membrane. Thus, interaction is likely mediated by molecules that span the cell membrane. These molecular adapters link the incorporation of newly synthesized cellular material with the MreB units, which thereby follow the permanently growing cell wall structures.
Many parts of the cell wall are almost universally conserved in bacteria, making it likely that the newly discovered mechanism is widespread. Hence, the results could play an important role for the further investigation of bacterial cells, but also for medicine: “Cell wall synthesis already is a key target for antibiotics. New insights into the structure of the cell wall could open up urgently needed therapeutic alternatives”, hopes Wedlich-Söldner. [UD]Original Publication:
* Equal contributionContact:
Anja Konschak | Max-Planck-Institut
Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences