Micron-scale plasma membrane curvature is recognized by the septin cytoskeleton

• Published in: The Journal of cell biology Vol. 213; no. 1; pp. 23 - 32
• Main Authors: Bridges, Andrew A, Jentzsch, Maximilian S, Oakes, Patrick W, Occhipinti, Patricia, Gladfelter, Amy S
• Format: Journal Article
• Language: English
• Published: United States Rockefeller University Press 11-04-2016; The Rockefeller University Press
• Subjects: Cell Membrane - metabolism; Cells; Cells, Cultured; Cytoskeleton; Cytoskeleton - metabolism; Fungi - metabolism; Humans; Lipid Bilayers - metabolism; Lipids; Membranes; Proteins; Septins - metabolism; Signal Transduction - physiology
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.201512029

Cells change shape in response to diverse environmental and developmental conditions, creating topologies with micron-scale features. Although individual proteins can sense nanometer-scale membrane curvature, it is unclear if a cell could also use nanometer-scale components to sense micron-scale contours, such as the cytokinetic furrow and base of neuronal branches. Septins are filament-forming proteins that serve as signaling platforms and are frequently associated with areas of the plasma membrane where there is micron-scale curvature, including the cytokinetic furrow and the base of cell protrusions. We report here that fungal and human septins are able to distinguish between different degrees of micron-scale curvature in cells. By preparing supported lipid bilayers on beads of different curvature, we reconstitute and measure the intrinsic septin curvature preference. We conclude that micron-scale curvature recognition is a fundamental property of the septin cytoskeleton that provides the cell with a mechanism to know its local shape.