Cryo-EM structures of PP2A:B55-FAM122A and PP2A:B55-ARPP19. (https://www.nature.com/articles/s41586-023-06870-3)

These scientists wanted to understand how cells divide and grow. They studied a process called the cell cycle, which is controlled by different chemicals in the cell. One of these chemicals is called phosphorylation, which helps the cell go through different stages of the cell cycle.

The scientists focused on a specific stage of the cell cycle called mitosis, where the cell splits into two new cells. They discovered that mitosis starts when certain proteins in the cell get more phosphorylation, and this is done by other chemicals called kinases. But, to stop mitosis and finish the cell division, another chemical called phosphatase needs to remove the phosphorylation from those proteins.

The scientists found two proteins called ARPP19 and FAM122A that can stop the phosphatase from removing the phosphorylation. They wanted to understand how these proteins work, so they used a special microscope called cryo-electron microscopy to look at the proteins and how they interact with each other.

They discovered that both ARPP19 and FAM122A can bind to the phosphatase in different ways. They used a technique called NMR spectroscopy to confirm their findings. By studying the structure and behavior of these proteins and the phosphatase, the scientists were able to understand how they work together to control the cell division process.

This research is important because it helps us understand how cells grow and divide, which is crucial for our bodies to function properly. It also provides insights that could be used to develop new medicines for diseases related to problems in this cell division process.

Padi SKR., Vos MR., Godek RJ., Fuller JR., Kruse T., Hein JB., Nilsson J., Kelker MS., Page R., Peti W. Cryo-EM structures of PP2A:B55-FAM122A and PP2A:B55-ARPP19. Nature. 2024 Jan;625(7993):195-203. doi: 10.1038/s41586-023-06870-3. Epub 2023 Dec 20.