SONA · Self-organising principles underlying nanodomain formation and function

Signal transduction of diverse inputs often relies on a comparatively small number of central signal integrators. The resulting question, how such a central signal transmission protein can recognise the specific input and trigger the respective, appropriate outputs is as of yet unresolved. However, recent research focusing on plant signal transduction suggested that the precise spatiotemporal organisation and the organisation of signalling modules into membrane nanodomains could play a crucial role in achieving signal specificity. A prime example in Arabidopsis is the GTPase RHO OF PLANTS (ROP)6 that forms nanodomains in the auxin-mediated gravitropic response as well as in osmotic stress. In SONA, I will use ROP6 as model system for membrane organisation at the nanoscale to dissect the self-organising principles of nanodomain formation and function. My host group and collaborators discovered how ROP6 assembles into nanodomains, which will be the foundation for a detailed and innovative characterisation of how protein-lipid interplay contributes to nanodomain specificity. Based on preliminary results, I will use live super-resolution microscopy to investigate how and where ROP6 nanodomains are nucleated after auxin and hyperosmotic treatment, respectively. In addition, I have two parallel, complementing goals in identifying the membrane lipids necessary for sustaining the nanodomains and the protein components required for feedback loops and specificity in ROP6 nanodomain signalling. Taken together, SONA will give insights into the membrane organisation of ROP6 nanodomains at unprecedented spatiotemporal resolution. It will also challenge our understanding of the signal transduction at the plasma membrane by emphasising how self-organising principles contribute to the formation of specific signalling modules. Finally, this action will provide me with valuable training to develop into an independent researcher in the field of plant lipid and membrane research.