Synergy between microtubule and actin networks in centrosome positioning

Centrosome positioning is important for cellular function, but the exact forces and spatial distribution that underly accurate centrosome centring in adherent cells remain unclear.

To assess the contribution of pushing and pulling forces exerted by microtubules to centrosome positioning, Manuel Théry and colleagues used laser ablation to investigate the effects of microtubule disruption. They observed that the microtubule and actin networks are closely connected as any centrosome recoil in response to microtubule ablation also results in a similar relaxation of surrounding actin filaments, indicating that microtubules are unable to generate the forces necessary to drive centrosome motion. Instead, the authors demonstrate that the actomyosin network creates a centripetal flow that drags the centrosome near the centre in adherent cells, and dynein-based transport along the microtubules is involved in the redistribution of cell mass around the centrosome to maintain the centrosomal position.