FOCAL POINT  (Left to right) Amy Foraker, Frances Brodsky, and colleagues (not pictured) reveal that clathrin promotes the maturation and structural integrity of centrosomes during mitosis. To demonstrate that clathrin affects centrosomes directly, rather than indirectly through its functions in spindle stabilization and cytokinesis, the researchers acutely inactivated clathrin during S phase, just before centrosome maturation. Compared with control cells (left), cells with cross-linked clathrin (right) have fragmented centrosomes (γ-tubulin, green; arrowheads) in early mitosis. Clathrin (with a SNAP-tagged light chain) is blue, and α-tubulin is red. Clathrin appears to promote centrosome integrity by forming a complex with the microtubule-binding proteins ch-TOG and TACC3.

PHOTOS COURTESY OF THE AUTHORS