Researchers at Karolinska Institutet and the University of Sussex have discovered that the process of copying DNA generates a brake signal that stalls cell division. This molecular brake ensures that the cell has two complete copies of DNA before it divides and thus prevents DNA damage and cancer development, the team reports in a paper published today in Molecular Cell.
"By creating cells that cannot copy their DNA and by following protein activities over time in single cells, we found that DNA replication blocks the enzymes that trigger cell division. Immediately after DNA replication is completed, the machinery that starts cell division is activated. This fundamental mechanism contributes to determining when human cells will divide," says Arne Lindqvist, senior researcher at the Karolinska Institutet who led the study.
The researchers also show that the molecular brake ensures that the amount of DNA damage is minimized. When the brake is not functional, the cell divides before it is ready resulting in large amounts of DNA damage.
"Our study highlights the dangerous consequences of hasty cell division and provides important clues on how cells might gain DNA mutations that ultimately give rise to cancer," says lead author Bennie Lemmens, postdoctoral researcher also at Karolinska Institutet.