The simulation shows the basic interactions in the cell, Actin filaments have several important functions in cells. On one hand, they support cell membranes by binding to them.
However, scientists do not know exactly how actin interacts with membrane lipids.
Simulations carried out by experiments at the University of Groningen give a molecular picture of this very basic process.
Actin filaments are involved in very important processes in eukaryotic cells, from motility to division and contraction of muscle fibers. Actin can also form tissue under the lipid bilayer. Here it provides additional support for this structure, while curved filaments also play a role in cell division when the membrane must contract. The simulation shows the basic interactions in the cell.
Although important, the molecular processes underlying the binding of actin to cell membranes are unclear.
Everyone agrees that negatively charged actin can bind to positively charged lipids, and some say that they can bind to the membrane even without a positive or even negative charge.
The latter is important for biological situations, because normal cell membranes carry negative charge in them.
Therefore, Marrink and his colleagues simulate the molecular dynamics of interactions between lipids and actin. They use the rough martini fields developed by Marrink and are used today throughout the world. The simulation shows the basic interactions in the cell.
By changing the components in the simulation, the scientists found that the ions that exist determine the binding process. Marrink: “Actin can only bind negatively charged lipids in the presence of calcium ions. The simulation shows the basic interactions in the cell.
Two positive calcium charges act as a kind of molecular glue. In contrast, calcium ions inhibit actin binding in the presence of positively charged lipids.
The calcium concentration needed in the simulation is higher than in the cell. However, calcium ions tend to bind to membrane lipids, so local concentrations can be quite high.
The results provide the first clear picture of the binding of actin to the membrane lipids. The simulation shows the basic interactions in the cell
The Dutch BaSyC project (Build a Synthetic Cell) consists of many different steps, one of which is membrane construction.
They need to be enriched with actin, so we need to understand how to control the interaction between the filament and the lipid membrane. And we must control the division of artificial cells where actin is needed for constriction.