Modulating microtubules through cell-free gene expression

Johannes Kattan

This project is a joint effort of the Danelon and Dogterom lab. We primarily work on the modulation of microtubules with the aim to asseble a minimal cell by a bottom-up approach.

One major problem we face in understanding life, is the complexity of modern cells. There are therefore several approaches to create simplified model systems to study life processes. One is the creation if a minimal cell, which can be definied as the most rudimentary system that is able to grow, reproduce and evolve. In an bottom-up approach, we combine existing biological components of different organisms in order to assemble such a system.

Figure 1: Concept of our minimal cell. Proteins are synthesed through gene expression from DNA templates inside of a liposome to achieve different tasks necessary for growth and division.

To this end, we use liposomes as a confinment of our system and a cell-free gene expression system as the core synthesis machinery. In this context, we want to use microtubules to deform the membrane of liposomes by polymerization forces. Futher, we want to utilze microtubules to polarize liposomes. This would be an essential step towards division. We aim to control all this processes through cell-free gene expression.

Figure 2: We want to utilize microtubles (green) combined with gene expression to achieve deformation and polarization of liposomes.

Figure 3: Tip-tracking assay with expressed Mal3. Here we demonstrate that we can express the protein Mal3 with our cell-free gene expression system. The expressed Mal3 is then enabling other factors to bind to the microtuble and cause the fluorescent labeling of the plus ends.