Centering and symmetry breaking in confined contracting actomyosin networks
Abstract
Centering and decentering of cellular components is essential for internal organization of cells and their ability to perform basic cellular functions such as division and motility. How cells achieve proper localization of their organelles is still not well-understood, especially in large cells such as oocytes. Here, we study actin-based positioning mechanisms in artificial cells with persistently contracting actomyosin networks, generated by encapsulating cytoplasmic Xenopus egg extracts into cell-sized ‘water-in-oil’ droplets. We observe size-dependent localization of the contraction center, with a symmetric configuration in larger cells and a polar one in smaller cells. Centering is achieved via a hydrodynamic mechanism based on Darcy friction between the contracting network and the surrounding cytoplasm. During symmetry breaking, transient attachments to the cell boundary drive the contraction center to a polar location. The centering mechanism is cell-cycle dependent and weakens considerably during interphase. Our findings demonstrate a robust, yet tunable, mechanism for subcellular localization.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 21, 2020
- Source ID
- 10.7554/elife.55368
Entities
People
- Alex Mogilner
- Angelika Manhart
- Bruce L Goode
- Enas Abu Shah
- Kinneret Keren
- Maya Malik-garbi
- Niv Ierushalmi
Organizations
- Army Research Office
- Brandeis University
- Israel Science Foundation
- National Institutes of Health
- National Science Foundation
- New York University
- Technion – Israel Institute of Technology
- University College London
- University of Oxford