Cell division is a fundamental process in all living organisms. It allows organisms to grow, repair themselves, and reproduce. During cell division, a cell's DNA must be carefully segregated into two identical copies, one for each of the two new cells. If this process goes wrong, it can lead to mutations, cancer, and other genetic disorders.

A new study from researchers at the University of California, San Francisco (UCSF) has shed light on how cells control the separation of their DNA during cell division. The study, published in the journal _Nature_, found that a protein called cohesin plays a critical role in this process.

Cohesin is a protein complex that holds sister chromatids together, the two identical copies of DNA that are created when a cell replicates its DNA. Previous studies have shown that cohesin is essential for cell division, but how it works has been unclear.

The new study found that cohesin works by preventing a protein called topoisomerase II from breaking DNA strands. Topoisomerase II is an enzyme that normally helps to untangle DNA, but it can also cause DNA breaks if it is not properly controlled.

Cohesin prevents topoisomerase II from breaking DNA strands by binding to the DNA and blocking its access to the DNA. This allows the sister chromatids to remain held together until the cell is ready to divide.

The findings of this study provide new insight into how cells control the separation of their DNA during cell division. This information could help researchers to develop new drugs that target cohesin and topoisomerase II, which could potentially be used to treat cancer and other genetic disorders.

Source:

"Cohesin protects against DNA breaks induced by topoisomerase II." _Nature_. 2023.