Symmetry Breaking and Emergence of Directional Flows in Minimal Actomyosin Cortices

Cells

Christian Wölfer¹  Kai Sundmacher¹  RobertJ. Flassig¹  DiegoA. Ramirez-Diaz²  SvenK. Vogel²  Petra Schwille² 

[1] Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, D-39106 Magdeburg, Germany;Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany;

关键词: bottom-up synthetic biology;    motor proteins;    pattern formation;    self-organization;   

DOI  :  10.3390/cells9061432

来源: DOAJ

【 摘 要 】

Cortical actomyosin flows, among other mechanisms, scale up spontaneous symmetry breaking and thus play pivotal roles in cell differentiation, division, and motility. According to many model systems, myosin motor-induced local contractions of initially isotropic actomyosin cortices are nucleation points for generating cortical flows. However, the positive feedback mechanisms by which spontaneous contractions can be amplified towards large-scale directed flows remain mostly speculative. To investigate such a process on spherical surfaces, we reconstituted and confined initially isotropic minimal actomyosin cortices to the interfaces of emulsion droplets. The presence of ATP leads to myosin-induced local contractions that self-organize and amplify into directed large-scale actomyosin flows. By combining our experiments with theory, we found that the feedback mechanism leading to a coordinated directional motion of actomyosin clusters can be described as asymmetric cluster vibrations, caused by intrinsic non-isotropic ATP consumption with spatial confinement. We identified fingerprints of vibrational states as the basis of directed motions by tracking individual actomyosin clusters. These vibrations may represent a generic key driver of directed actomyosin flows under spatial confinement in vitro and in living systems.

【 授权许可】

Unknown