Based on the novel method used in this study, the researchers can now begin to build an accurate model for mitosis.

Sussex research has demonstrated how two proteins work in tandem to initiate and complete the process of cell division.

The proteins, called cyclin A and cyclin B, have long been associated with the complex process of cell division, or mitosis, but until now it has been unclear what each is responsible for, and how the two work together.

An international group of researchers, led by Dr Helfrid Hochegger of the Genome Damage and Stability Centre, developed a novel method to rapidly induce degradation of these cyclins and study the impact this has on cell division.

They demonstrated that cyclin A is essential in initiating cell division and cyclin B completes the process.

Dr Hochegger said: “These findings change our view on how cell division is controlled in human cells and how this process has evolved to be extremely robust.

“Our method of induced degradation of endogenous proteins based on CRISPR mediated gene targeting can also be widely applied in molecular genetics and cell biology.”

The findings showed that the loss of cyclin A in a cell prevented mitotic entry. While cells lacking cyclin B could enter mitosis, but they could not complete the process.

The barrier which prevented the completion of mitosis in cells lacking in cyclin B was the breakdown of the nuclear envelope in the cell, which requires a delicate balance of proteins to complete the process of producing two functional cells from one.

Based on the novel method used in this study, the researchers can now begin to build an accurate model for mitosis.

It is hoped that this will enable them to analyse how the process differs in cancer cells, which could lead to new targets for treatment options.

Cyclin A triggers Mitosis either via the Greatwall kinase pathway or Cyclin B is published in The EMBO Journal.