Invitée direction: Keren Lasker, The Scripps Research Institute, La Jolla, CA, USA – “The PopZ condensate: from cytosol organization in bacteria to synthetic applications in human”

Résumé

Intracellular phase separation is emerging as a universal principle for organizing biochemical reactions in time and space. It remains incompletely resolved how biological function is encoded in these assemblies and whether this depends on their material state. The conserved intrinsically disordered protein PopZ forms condensates at the poles of the bacterium Caulobacter crescentus, which in turn orchestrate cell-cycle regulating signaling cascades. During my presentation, I will introduce a model of PopZ condensation and show that the material properties of these condensates are determined by a balance between attractive and repulsive forces mediated by a helical oligomerization domain and an expanded disordered region, respectively. I will discuss a series of PopZ mutants that alter this equilibrium, producing condensates with a range of material properties from liquid-like to solid states. Lastly, I will explore how these findings enable us to harness PopZ as a versatile framework for creating adjustable synthetic condensates in human cells, opening up new avenues in synthetic biology.