A new model for the formation of essential structures in the cell membrane changes the picture of cellular dynamics
The cell membrane is a busy crossroads. In the life of the cell it plays a crucial role - it allows entry into and exit from the cell. Researchers from the Weizmann Institute of Science, together with scientists from Ben-Gurion University of the Negev and the University of Bremen in Germany, recently overturned the common assumption regarding the formation of "rounded folds" on the membrane, which allow movement in and out. The basic understanding regarding the dynamics in the cell membrane may help, among other things, in the effort to understand how cancer cells receive nutrients or signals, and how they migrate in the body. the study Recently published in the scientific journal Nature Communications..
Parts of the cell membrane are constantly "remodeling". For example, when the cell needs to receive or deliver "large packages", it does so by creating bubbles near the surface. Actin fibers, which provide structural support to the cell, play a central role in the remodeling process - they break down and reorganize as needed. A characteristic shape of the actin filaments, which appears in preparation for bleb formation, is a rounded cup-shaped fold on the exposed surface of the cell. In the past, the progress of the process of creating the folds was described as pulses, with dynamics similar to that of electrical impulses (pulses). But Prof. Nir Gov from the Department of Chemical Physics at the Weizmann Institute of Science, Dr. Eric Yochelis from Ben-Gurion University, together with Dr. Eric Burnit and Prof. Hans-Ginther Dobreiner from the University of Bremen, re-examined the formation of these structures, and realized that what exists There is no pulse mechanism.
Understanding this mechanism may contribute, among other things, to cancer research, because in some types of cancer the wave dynamics are suppressed or impaired. In addition, cancer cells may use the rounded folds to absorb more nutrients or rearrange their cell membranes, thus migrating through the body more efficiently.
Mathematical simulations conducted in the two Israeli laboratories, and experiments with living cells carried out in Germany, showed that a more appropriate description of the movement of the circular folds is a wave front. This type of dynamic structure, well known to physicists, exists when the cell membrane has two areas that differ in their actin concentration, with a moving front between them. In laboratory experiments, it was proven that the model created by the researchers is able to predict the movement of actin waves on the cell membrane. Unlike other spreading waves, which continue outward, these rounded folds fold inward, toward their point of origin. The collapse to this particular point is necessary for the creation of the final bubble which surrounds and separates the material transferred through the membrane. The new model describes this unique feature - something that none of the previous models did.
Understanding this mechanism may contribute, among other things, to cancer research, because in some types of cancer the wave dynamics are suppressed or impaired. In addition, cancer cells may use the rounded folds to absorb more nutrients or rearrange their cell membranes, thus migrating through the body more efficiently. "Now that we understand these waves better, we may learn how to control their dynamics," says Prof. Gov. And Dr. Yoghelis adds: "Theoretically, we can help identify processes in cancer cells that have so far been overlooked."
