Mechanical Centrosome Fracturing during Cell Navigation

The centrosome is the primary microtubule orchestrator in most eukaryotic cells, nucleating and anchoring microtubules that grow radially and exert forces on cargos. At the same time, mechanical stresses from the microenvironment and cellular shape changes compress and bend microtubules. Yet, centrosomes are membrane-less organelles, raising the question of how centrosomes withstand mechanical forces. Here we discover that centrosomes in non-dividing cells can mechanically fracture. We reveal that centrosomes experience mechanical deformations during microenvironmental confinement and navigational pathfinding by motile cells. Coherence of the centrosome is maintained by Dyrk3, preventing fracturing by mechanical forces. Centrosome fracturing impedes cellular function by generating coexisting microtubule organizing centers that compete during path navigation and thereby cause cellular entanglement in the microenvironment. Our findings show that non-dividing cells actively maintain the integrity of the centrosome to withstand mechanical forces. Given that almost all cells in multicellular organism experience forces, these results suggest that centrosome stability preservation is fundamental during development, tissue maintenance, immunology, and disease.