Major interactions of structural proteins based on calmodulin cell junctions. The actin filament is attached to α-actinin, which is attached to the membrane via vinculin. The head of the nucleoprotein is attached to E-calmodulin via α-, ß- and γ-linkin. The tail of nucleoprotein is bound to membrane lipids and actin filaments. (Public Domain)
How can the fleshy tissues of the human body bond together so strongly? Scientists have discovered that a special protein, calmodulin (cadherins), plays an important role in holding cells together.
Calmodulin is an important protein in the body that is responsible for the adhesion of many body tissues, including nerves, heart, placenta and skin, helping these cells and tissues maintain their function and shape.
These bulky, rod-shaped proteins are responsible for the transmission of information inside and outside the cell wall. They can bind to other calmodulin within this cell as well as to calmodulin on other cells.
Scientists first discovered these proteins more than 40 years ago, but have been puzzled by the weakness of the binding between individual such proteins. “There are important unanswered questions about the glue between cells and tissues.” Daniel K. Schwartz, a professor of chemical and biological engineering at the University of Colorado Boulder, said, “It appears that the binding between these proteins is weak, but the cells in the tissues are firmly held together. There are still large gaps in our understanding of these proteins.”
The study, published March 9 in the Proceedings of the National Academy of Sciences (PNAS), finally helps fill that gap.
This study found that while the binding between individual proteins is weak, multiple proteins bonded together have a “devil’s felt”-like effect, making the bonding stronger and more durable. Not only are proteins within the same cell more strongly bound, but also between cells – up to 30 times stronger than the binding strength between individual proteins. And once the bindings are formed, the bonds between them get tighter and tighter.
The “devil’s felt” is Velcro, consisting of two fabrics, one covered with loops and the other with hooks. When the two fabrics are pressed firmly, the hooks and loops combine to form a tight fit.
A better understanding of these proteins could help in the design of more simulated human tissues or the invention of targeted and more effective anti-cancer drugs,” said Connor Thompson of the Department of Chemical and Biological Engineering at the University of Colorado Boulder, lead author of the study. and more effective anti-cancer drugs.”
For example, Thompson said, new anti-cancer drugs could be designed to slow tumor growth by blocking the interaction between these calmodulin proteins and stopping or slowing the formation of new blood vessels on tumor cells.