Shape matters at the intracellular post-office
New insights on how lipids control the shape and function of the Golgi complex reported in eLife.
The Golgi complex receives freshly made proteins, processes them, and finally sends them to different places inside or outside the cell, where these proteins need to perform their functions. The Golgi complex is formed by a stack of flat membranes, named cisternae, which enclose a very small volume inside. These membranes, just like any other membranes inside the cell, are made of lipids and proteins. What are these lipids and proteins doing to keep the peculiar shape of the Golgi cisternae? Is this shape important for the Golgi complex to perform its functions efficiently?
Dr. Felix Campelo and colleagues used physical concepts, such as elasticity or entropy, to mathematically describe how a Golgi cisterna can retain or change its shape. The theory predicts that some proteins keep the cisternae flat by holding the membrane rim that connects the two faces of a cisterna. To test this prediction, the researchers did experiments in human cells and found that when the Golgi lipid composition changes, certain proteins jump from the rim causing the cisternae to curl. Remarkably, these proteins are also needed to export cargo proteins, demonstrating that there is a connection between Golgi shape and function.
The shape of the Golgi complex is affected in many neurodegenerative diseases, such as in Alzheimer’s disease. The results obtained during this research will contribute to further our understanding on how the shape of the Golgi is affected in these diseases, what are the consequences for the cell, and if this effect can be somehow prevented.