Lipid Chemistry Empowers Nuclear Shape

(© Image: Depositphotos) - The cell nucleus is surrounded by a spherical double membrane called the nuclear envelope. Scientists have long been intrigued by how this envelope can be elastic enough to accommodate shape changes that cells experience as they move through tissues, but also rigid enough to maintain nuclear integrity. A study by Anete Romanauska and Alwin Köhler (MedUni Vienna/Max Perutz Labs), published in Nature Cell Biology, uncovers that the chemistry of membrane lipids is key for this versatility. When this chemistry is perturbed, the nuclear membranes become stiff and prone to rupture, and nuclei lose their typical round shape and morph into a polyhedron. The nuclear envelope is essential to protect the genome and to regulate traffic in and out of the nucleus. Anata Romanauska and Alwin Köhler initially from the Max Perutz Labs and the Division of Molecular Biology at MedUni Vienna asked a simple, yet fundamental question: what makes the cell nucleus round? Despite variations in nuclear shape in different cell types, from spherical to ovoid and sometimes multilobed, cell nuclei are typically devoid of edges. The two scientists suspected that the nature of lipids, more specifically their saturation state, may play a role in keeping nuclei round.