Abstract

Every time a cell divides, it must make a complete and accurate copy of its DNA. This process, called DNA replication, is essential for all life. If errors occur during replication, they can lead to serious problems, including cancer and genetic diseases. I focused on a protein called RECQ4, which plays an important role in the initiation of DNA replication. Mutations in RECQ4 lead to the development of severe hereditary diseases, but its precise role in DNA replication is still poorly understood.

In my research, I investigated how two other proteins, MCM10 and CDC45, regulate RECQ4. I found that CDC45 reduces RECQ4’s activity, keeping it inactive until the right time. MCM10, on the other hand, stimulates RECQ4’s activity and helps initiate DNA replication. These results show that RECQ4 is carefully regulated to ensure that DNA replication begins only at the correct moment.

Understanding how RECQ4 is regulated is important because mutations in this protein cause severe hereditary disorders such as Rothmund-Thomson, RAPADILINO, and Baller-Gerold syndromes. In addition, unusually high levels of RECQ4 have been linked to the development of cancer. By clarifying how MCM10 and CDC45 regulate RECQ4, my research provides new insight into the mechanisms that safeguard DNA replication. In the long term, this knowledge may help explain the molecular basis of RECQ4-related diseases and guide future strategies for diagnosis or treatment.