Medical Research Council - London Institute of Medical Sciences

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Dwindled Spindles

Importance of protein annexin A1 in getting cell division right

12 February 2023

Dwindled Spindles

When our cells are cleaved in two during mitosis, spindles are tiny systems of ‘fibres’ that pull the DNA inside apart. Each daughter cell must be identical, but they also have to fit into the plan for the overall tissue. In these human cells, researchers find a protein in the cell membrane called annexin A1 that juggles these priorities – coordinating the spindles on the inside with chemical cues from neighbouring cells, allowing the DNA (purple) to split to opposite sides of the cell in the top row. The direction or polarity of dividing cells is especially important in the patterning of developing tissues. Losing annexin A1 (lower rows) leaves mitosis struggling, with many of the spindles malformed – in many cases mitosis fails to complete. Investigating other proteins that work towards the 'big picture' may help researchers to understand and guide cell division in health and disease.

Written by John Ankers

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