The Architecture of Traveling Actin Waves Revealed by Cryo-Electron Tomography
Marion Jasnin, Florian Beck, Mary Ecke, Yoshiyuki Fukuda, Antonio Martinez-Sanchez, Wolfgang Baumeister, Günther Gerisch - Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
Actin waves are dynamic supramolecular structures involved in cell migration, cytokinesis, adhesion, and neurogenesis. Although wave-like propagation of actin networks is a widespread phenomenon, the actin architecture underlying wave propagation remained unknown. In situ cryo-electron tomography of Dictyostelium cells unveils the wave architecture and provides evidence for wave progression by de novo actin nucleation. Subtomogram averaging reveals the structure of Arp2/3 complex-mediated branch junctions in their native state, and enables quantitative analysis of the 3D organization of branching within the waves.