Understanding how cells copy their genetic material, or DNA, is crucial for comprehending life itself. This knowledge helps us understand diseases and develop new treatments. Scientists have been working to uncover the complex processes involved in DNA replication, which is essential for cell division and the transmission of genetic information.
A recent review published in Current Opinion in Structural Biology by researchers from the Institute of Biophysics of the Chinese Academy of Sciences delves into the molecular mechanisms that ensure the accurate duplication of genetic and epigenetic information during DNA replication in eukaryotic cells. The study focuses on how cells maintain their original epigenetic landscape while ensuring the integrity of the genome.
DNA replication temporarily disrupts the structure of chromatin, which is the complex of DNA and proteins that packages the genetic material within the nucleus of a cell. The process of replication-coupled (RC) nucleosome assembly is central to this. This requires the precise coordination of newly synthesized and recycled histones, which are proteins that DNA wraps around.
Histone chaperones, special proteins that guide histones, play a key role in this process. The assembly of RC nucleosomes occurs through two pathways: one using newly created histones, facilitated by the chromatin assembly factor 1 (CAF-1) complex, and another using recycled histones, involving the FACT complex. The researchers summarized the latest advancements in the structural biology of RC nucleosome assembly, focusing on how the CAF-1 complex assembles new histone H3-H4 tetrasomes and how the FACT complex recycles parental histone hexamers.
These structural studies provide insights into how epigenetic information is inherited. Furthermore, they offer new avenues for developing anticancer drugs that target the chromatin assembly process. The researchers also explored how histone chaperones interact with the replication machinery, expanding the role of molecular chaperones to include their function within the DNA replisome, the complex of proteins involved in DNA replication.
The review highlights the importance of understanding the coupling between DNA replication and chromatin assembly. This knowledge is valuable for developing new treatments for diseases like cancer. By understanding these intricate processes, scientists can develop targeted therapies that interfere with the abnormal replication of cells.