Nuclear envelope-associated dynein cooperates with Eg5 to drive prophase centrosome separation.

Eg5 (kinesin-5) is a highly conserved microtubule motor protein, essential for centrosome separation and bipolar spindle assembly in human cells. Using an "in vitro" evolution approach, we generated human cancer cells that can grow in the complete absence of Eg5 activity. Characterization of these Eg5-independent cells (EICs) led to the identification of a novel pathway for prophase centrosome separation, which depends on nuclear envelope (NE)-associated dynein. Here, we discuss our recent findings and elaborate on the mechanism by which dynein drives centrosome separation.