Proceedings

EPJ E Highlight - How cells get a skeleton

alt
Microscopy image of a cell.

Stress generated by nano-motors within animal cells can lead to the creation of a condensed layer of filaments beneath the outer cell membrane

The mechanism responsible for generating part of the skeletal support for the membrane in animal cells is not yet clearly understood. Now, Jean-François Joanny from the Physico Chemistry Curie Unit at the Curie Institute in Paris and colleagues have found that a well-defined layer beneath the cell outer membrane forms beyond a certain critical level of stress generated by motor proteins within the cellular system. These findings, which offer a new understanding of the formation of this so-called cortical layer, have just been published in EPJ E.

Active gels are ideal for modelling the similar material found in living cells’ structure, made of a dynamic, filamentous scaffold. They are composed of components that take up energy and do directed work. Indeed, chemical energy is fed into the cells’ constituents and is transformed into mechanical work through the assembly of its internal filaments, made of a polymer called actin, and a protein that functions as a tiny motor, called myosin. Both provide the active gel-like substance found in cells with a spontaneous tendency to contract. As a result, the cells can either maintain or change their shape, or even adhere, spread, divide and crawl.

In this study, the authors have created hydrodynamic models of active gels to model the cell cortex, whereby the active gel is polymerising at the surface and depolymerising throughout the gel as a whole. They first derived the equations providing a coarse-grained description of cortical dynamics, then calculated the configuration in which their model was in a steady state.

They found that for sufficiently high levels of contractile stress it consisted of a dense layer near the membrane, which abruptly cut off beyond a certain thickness. The key advance in their model is the inclusion of gel disassembly throughout the system, and the contractility due to molecular motors.

The actin cortex as an active wetting layer. J.-F. Joanny et al. (2013), European Physical Journal E 36: 52, DOI 10.1140/epje/i2013-13052-9

This was our first experience of publishing with EPJ Web of Conferences. We contacted the publisher in the middle of September, just one month prior to the Conference, but everything went through smoothly. We have had published MNPS Proceedings with different publishers in the past, and would like to tell that the EPJ Web of Conferences team was probably the best, very quick, helpful and interactive. Typically, we were getting responses from EPJ Web of Conferences team within less than an hour and have had help at every production stage.
We are very thankful to Solange Guenot, Web of Conferences Publishing Editor, and Isabelle Houlbert, Web of Conferences Production Editor, for their support. These ladies are top-level professionals, who made a great contribution to the success of this issue. We are fully satisfied with the publication of the Conference Proceedings and are looking forward to further cooperation. The publication was very fast, easy and of high quality. My colleagues and I strongly recommend EPJ Web of Conferences to anyone, who is interested in quick high-quality publication of conference proceedings.

On behalf of the Organizing and Program Committees and Editorial Team of MNPS-2019, Dr. Alexey B. Nadykto, Moscow State Technological University “STANKIN”, Moscow, Russia. EPJ Web of Conferences vol. 224 (2019)

ISSN: 2100-014X (Electronic Edition)

© EDP Sciences