Cutting it fine: mechanical regulation of microtubule abscission

At the end of cell division, the two sister cells must completely separate. Abscission is the last step of cell division and consists in the cutting of a cytoplasmic bridge linking the two cells. Abscission is mediated by the membrane remodelling machinery ESCRT which also triggers the severing of a thick bundle of microtubules that needs to be cleared prior to abscission. However, the duration of abscission can vary widely from one cell type to the other; in particular, cells with bridges under tension undergo slow abscission. Here, we use mouse embryonic stem cells which can shuttle between a slow and a fast abscission depending on their pluripotency status to investigate the mechanical regulation of abscission. We show that mechanical forces impact abscission through the regulation of microtubule removal from the bridge and explore the underlying molecular mechanisms.