Long-range transport of biomolecular condensates by Marangoni effect

In a groundbreaking study, researchers have uncovered a new mechanism of intracellular transport in cells. The work focuses on how large molecular assemblies, called biomolecular condensates, are relocated within cells. Typically, the movement and positioning of these condensates within cells is not entirely understood, except that they can move via dissolution-recondensation.

The study, conducted using microfluidic reconstitution, quantitative micropipette aspiration, and live-cell imaging, demonstrates that a specific gradient of MEG-3 protein concentration creates an interfacial-tension asymmetry. This asymmetry drives the directed motion of these condensates from the anterior to the posterior region of the cell. This process is made possible through the Marangoni effect, an existing phenomenon where temperature or concentration differences at a liquid's surface drive fluid motion.

The researchers performed orthogonal molecular perturbations to test their findings. These perturbations either abolished or reversed the directional migration of the condensates, directly linking the interfacial properties to the transport behavior. This provides direct causal evidence that the emergent properties of condensates can contribute to the overall organization of the cell.

The findings of this study indicate that the Marangoni effect is a previously unrecognized mechanism for the transport of biomolecular condensates within cells. This discovery opens up new avenues for understanding cellular organization and the specific roles played by biomolecular condensates.