The material properties of a bacterial-derived biomolecular condensate tune biological function in natural and synthetic systems

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. Here we 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. A series of PopZ mutants disrupting this balance results in condensates that span the material properties spectrum, from liquid to solid. A narrow range of condensate material properties supports proper cell division, linking emergent properties to organismal fitness. We use these insights to repurpose PopZ as a modular platform for generating tunable synthetic condensates in human cells

The material properties of a bacterial-derived biomolecular condensate tune biological function in natural and synthetic systems.

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. Here we 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. A series of PopZ mutants disrupting this balance results in condensates that span the material properties spectrum, from liquid to solid. A narrow range of condensate material properties supports proper cell division, linking emergent properties to organismal fitness. We use these insights to repurpose PopZ as a modular platform for generating tunable synthetic condensates in human cells

Swimming against the stream: investigating psychosocial flows through mindful awareness

In this paper, we extend psychosocial research methodology by integrating a breaching experiment, influenced by ethnomethodological sociology, with aspects of mindfulness practice, influenced by Buddhist traditions. We offer an empirical investigation of what happens when researcher-participants subtly ‘swim against the stream’ of normative public social conduct in a capital city setting. Our qualitative analysis explores a single case from a corpus of 172 first-person retrospective accounts of standing still and ‘doing nothing’ in a busy, public place. We investigate the qualitative aspects of how one researcher-participant arguably adopted a mindful, ‘beginner’s mind’ orientation toward the flow of psychosocial consciousness. We empirically investigate this psychosocial orientation of mindfulness by integrating Wetherell’s concept of affective-discursive practice with James’ stream of consciousness. Mindfulness offers a specific, embodied reorientation toward psychosocial flows. We discuss the methodological implications and limitations of this reorientation for psychosocial research