Unusual Proteins Can Tell Us About Stem Cells

Stem cells could be a crucial puzzle piece in studying the early stages of human life. These little factories are known for their ability to become many different types of cells in the body. While scientists are familiar with different types of stem cells corresponding to different stages of human development, they still don't fully understand how these cells are built and interact with their surroundings. Researchers took a closer look at how the cytoskeleton, the cell's structural framework, changes as stem cells transition from one state to another. They found some interesting things about a specific type of stem cell called mouse embryonic stem cells, or mESCs. These mESCs have some unusual features. They have prominent structures made of actin and cadherins, which are proteins that usually help cells stick together. In these cells, the structures don't actually connect cells to each other. The scientists called them Non-Junctional Cadherin Complexes (NJCCs).These structures are under low mechanical tension, depend on a specific part of a protein known as E-cadherin, and don't require much calcium to function. The researchers discovered that a protein called Rac1 plays a significant role in breaking down these NJCCs. It does this by promoting the separation of another protein, beta-catenin, from the complex. The scientists believe that these NJCCs might have an essential role in maintaining the ground-state pluripotency of stem cells. They could also serve as markers to identify different types of stem cells in a mixed population. All of this information could have broad implications for how scientists understand and work with stem cells in the future. It could help create new ways to study and control these cells. As scientists continue to investigate these findings, they may uncover even more about the mysteries of stem cells.