Super-resolution rendering of separating centrosomes, microtubule asters (grey) and the actin ring (red) around the nucleus (blue). Image credit Dr Tom Stiff

Scientists have discovered a novel mechanism by which cells arrange their structure during the complex process of cell division, or mitosis.

Centrosomes are tiny units, or organelles, within cells that are responsible for arranging cell structure via the cytoskeleton (a network of proteins which primarily functions to give the cell its shape).

It is crucial that these centrosomes maintain a well-defined position within the cell, especially during cell division.

Research led by Dr Helfrid Hochegger of the Genome Damage and Stability Centre has now uncovered a novel mechanism that reveals how the cell controls the position of these centrosomes, and therefore the whole cell structure, in the early stages of mitosis.

The researchers studied how the protein actin works with microtubule proteins (components that make up the cytoskeleton) to regulate and coordinate the positioning of centrosomes during cell division.

Dr Hochegger said: “Our study has revealed a novel cytoskeletal structure, a transient perinuclear actin ring, that is critical for genome maintenance and accurate cell division. We also found the position of the nucleus is crucial for this process.

“We analysed how actin and the Microtubule cytoskeleton work together to achieve this positioning mechanism.”

It is expected that this research will allow future studies on how the cell structure is regulated during mitosis. It is also hoped that by studying how this mechanism is deregulated in cancer, new targets for therapeutic intervention could be discovered.

Prophase-Specific Perinuclear Actin Coordinates Centrosome Separation and Positioning to Ensure Accurate Chromosome Segregation is published in Cell Reports.