Membrane remodeling and higher-order structure formation by DivIVA

Membrane dynamics, including remodeling, fusion and fission, are essential in both prokaryotic and eukaryotic cells. They are involved in processes such as cell division, intracellular transport, and the maintenance of organelle structure. In eukaryotes, these processes are regulated by complex systems, such as the SNARE complex and dynamin-related proteins. Prokaryotes, which possess a simpler cellular organization, employ flotillins and dynamin-like proteins for membrane modulation and rely on cytoskeletal components and Min proteins to control cell division septum positioning. Cardiolipin, a phospholipid enriched at sites of membrane curvature, participates in modulating membrane morphology. In gram-positive bacteria, the peripheral membrane protein DivIVA exhibits higher affinity for cardiolipin and localizes to sites of negative curvature. DivIVA is a topological determinant of many proteins, including the Min proteins, which negatively regulate cell division. Although DivIVA helps control the spatial positioning of cell division, the mechanisms of its membrane interaction and influence on morphology remain unclear. Here, we show that DivIVA forms higher-order assemblies on the membrane and enhances changes in membrane morphology. These findings support the hypothesis that DivIVA might have an active role in membrane remodeling and provide insights into the interaction between this bacterial protein and the membrane. • Using AFM, cryo-EM, and liposome assays Clostridioides difficile DivIVA effect on membranes was studied in detail. • DivIVA bound cardiolipin-rich bilayers and induced membrane budding, disruption, and fusion, and formed basket-like assemblies in curved regions. • DivIVA might be an active driver of bacterial membrane remodeling and division.