The formation of the mitotic spindle depends on just two molecules

Researchers at the Centre for Genomic Regulation (GRG) and the University of Cambridge have discovered that only kinesin-5 and dynein, two motor proteins, are required to form a functional mitotic spindle. The other factors involved would only stabilise and refine the system.

The mitotic spindle, made up of rods called microtubules, is the molecular machine responsible for cell division or mitosis. Although widely represented, its name is less well known. It is that oval-shaped structure that forms to separate chromosomes. The mitotic spindle is responsible for separating the genetic material equally between the two poles to form daughter cells.

The study was carried out through computational simulations using the Cytosim platform created by François Nédélec, co-lead author of the paper in Cambridge. This software simulates the mechanical and chemical behaviour of microtubules and associated proteins. ‘Exploring multiple protein designs and properties in simulations helps us understand why these proteins have evolved into their current form,’ explains Wei-Xiang Chew, a postdoctoral researcher in Thomas Surrey’s group at the CRG and first author of the study.

“It’s remarkable how simple it is to construct the basic shape of a spindle”

Thomas Surrey (CRG), co-senior author of the paper and ICREA Research Professor

This analysis could help to understand diseases caused by irregular cell divisions, such as cancer. In addition, knowing how the spindle is formed would contribute to its construction in the laboratory, which would facilitate research into treatments for the same diseases.