Each time our cells divide, they need to replicate their DNA to pass on their genetic material to the two daughter cells. To create identical copies of the DNA the double helix is separated, and each strand acts as a template to create a new copy. This process requires many sequential steps, like an assembly line in a factory. One important step is placing PCNA sliding clamps, depicted as small silver clasps, onto the newly produced DNA. The loading and unloading of these clamps is mediated by the robot arms, which represent protein complexes of different compositions.
A new finding reveals that two of these complexes, RFC-Rfc1 and RFC-Ctf18, play distinct roles on different sides of the production line. The clamps loaded by the yellow Rfc1 complex are essential for replication, while the clamps placed by the orange Ctf18 are important for loading the large gold cohesin rings, which keep the newly copied DNA strands together until the cells divide.
This division of labor between the robot arms creates a balanced distribution of PCNA clamps on both of the replicated DNA strands, and is essential for proper DNA replication and cell division.
Read more about the research in this Molecular Cell paper.
Congratulations to the Uhlmann lab at The Francis Crick Institute and first author Hon Liu, who I had the pleasure to meet during a summer program in my PhD lab at the Institute of Molecular Biotechnology and the Vienna BioCenter!
