Martin Thanbichler

Martin Thanbichler

Prof. Dr. Martin Thanbichler

Biology, Philipps University & Max Planck Institute for Terrestrial Microbiology
Prokaryotic Cell Biology
Hans-Meerwein-Straße 4, 35032 Marburg
+49-6421 28 21809
thanbichler@uni-marburg.de
http://www.ThanbichlerLab.org

Research area

The aim of our group is to understand the molecular basis of cellular differentiation, morphogenesis, and cell division in bacteria and to elucidate how one-dimensional genetic information is translated into defined spatial and temporal regulatory patterns. To address these questions, we are using a combination of cell biological, biochemical, structural, and bioinformatic approaches. Our studies focus primarily on the model organism Caulobacter crescentus, a Gram-negative bacterium that is characterized by its unique developmental cycle. In addition, we have extended our work to alternative model systems to facilitate comparative studies.



Research project within SYNMIKRO

 

Intracellular protein gradients play a critical role in the spatial organization of both prokaryotic and eukaryotic cells, but in most cases the precise mechanisms underlying their formation are still unclear. We are investigating the function of a gradient-forming system, based on the conserved ATPase MipZ, that determines division site placement in the differentiating bacterium Caulobacter crescentus. MipZ interacts with a kinetochore-like nucleoprotein complex formed by the DNA partitioning protein ParB in proximity of the chromosomal origin of replication. Upon entry into S-phase, the two newly duplicated origin regions are segregated and tethered to opposite cell poles, giving rise to a bipolar distribution of MipZ, with a defined concentration minimum at the cell center. Since MipZ acts as an inhibitor of divisome formation, its gradient-like pattern effectively confines cytokinesis to the midcell region.

In collaboration wNukleotidbindung und –hydrolyse führen zu einer Oszillation von MipZ zwischen den polaren ParB-Komplexen und dem Nukleoid und somit zu einer Akkumulation von MipZ in den polaren Regionen der Zelle.ith the group of Peter Lenz, we are using a combination of biochemistry, cell biology and computational modelling to investigate the mechanism driving formation of the MipZ gradient. We have solved the crystal structures of MipZ in the apo and ATP-bound state and started to dissect the determinants that ensures the dynamic recruitment of MipZ to the polar regions of the cell. Our results indicate that MipZ alternates between distinct conformational states that display marked differences in their interaction networks and diffusion rates. As a consequence, the protein undergoes an elaborate localization cycle, involving its oscillation between the polar ParB complexes and pole-distal regions of the nucleoid. The MipZ gradient thus represents the steady-state distribution of molecules in a highly dynamic system. Our work enlightens the principles that govern the establishment of a regulatory protein gradient within the confined space of the bacterial cytoplasm and provide the basis for the future implementation of gradient-forming systems in synthetic cells.

SYNMIKRO Young Researchers Groups

Almost all scientific members of SYNMIKRO are actively involved in DFG’s Collaborative Research Centers (Sonderforschungsbereiche), Research Training Groups (Graduiertenkollegs), or other Cooperative Research projects. Alongside performing adventurous experiments, and reporting excellent science, SYNMIKRO substantially promotes potential Young Research Group Leaders by constantly keeping its doors open to welcome and support Young Researchers planning to set up an Independent Research Group.
Our Young Research Groups