Inside cells, there exists an extensive system of canals known as the endoplasmic reticulum (ER), which consists of membrane-encased tubes that are partially broken down as needed – for instance in case of a nutrient deficiency. As part of this process, bulges or protrusions form in the membrane, which then pinch off and are recycled by the cell. A study by Goethe University Frankfurt has examined this protrusion process using computer simulations. Its finding: certain structural motifs of proteins in the ER membrane play a central role in this process. The study was carried out as part of the “SCALE – Subcellular Architecture of Life” cluster initiative.