Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
Elife January 1, 2020; 9

Centering and symmetry breaking in confined contracting actomyosin networks.

Ierushalmi N , Malik-Garbi M , Manhart A , Abu Shah E , Goode BL , Mogilner A , Keren K .

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.

PubMed ID: 32314730
PMC ID: PMC7173961
Article link: Elife
Grant support: [+]

Species referenced: Xenopus
Genes referenced: acta1 trim9

Article Images: [+] show captions
References [+] :
Abu Shah, Reconstitution of cortical actin networks within water-in-oil emulsions. 2016, Pubmed, Xenbase