Yeast cells seeking to unite with their "beloved" face a difficult problem: the inability to move on their own. To meet a potential mate, the least they can do is "send their arms" to him.
Yeast cells seeking to unite with their "beloved" face a difficult problem: the inability to move on their own. To meet a potential partner, the least they can do is "send their arms" to him. These arms are actually cellular extensions that allow the two cells to meet. The membranes between them fuse, and a fusion of the genome takes place - that is, mating or sexual reproduction. Research by Prof. Geoffrey Gerst and (then) research student Dr. Rita Glin-Licht, from the Department of Molecular Genetics at the institute, recently discovered an important factor that ensures the meeting of the "lovers": the mechanism that controls the direction of the growth of the cellular extensions (called shmoos ), it seems that a similar mechanism is responsible for the formation of cellular extensions in other organisms. An example of this is the nerve cells in the brain, which form long extensions (axons). In the direction of other cells in the case of positive signals, or withdraw from them in the case of negative signals, thus creating a complex and branched pattern that networks the brain.
The scientists discovered that when yeast cells ready for sexual reproduction receive a chemical signal from a potential partner, messenger RNA molecules - which carry the DNA's genetic code for its translation into protein - are sent to the desired location, near the cell membrane - there Received the chemical signal from the partner. It is the proteins translated from those messenger RNA molecules that create, on the spot, the extensions. Such a process, in which a chemical signal coming from some cell causes the formation of extensions in its direction, is called "chemotropism". In addition, the scientists discovered exactly how the messenger RNA molecules reach the desired location: it turns out that a certain protein, called Scp160, is activated through the chemical signaling, and leads the necessary messenger RNA molecules to the appropriate location near the cell membrane. When the scientists created a targeted mutation in the Scp160 protein, and impaired its activity, the yeast cells grew extensions in the wrong directions, and were unable to mate. The findings of the research, which was done in collaboration with scientists from John Hopkins University, were recently published in the scientific journal Cell Reports.
In previous studies, Prof. Gerst discovered that messenger RNA molecules do not move randomly in the cell, but are transported to the exact place where the protein is needed, and are translated there. The present study proves for the first time that this precise targeting of messenger RNA is essential for the cell's ability to respond to external chemical signals.
If it turns out that these findings are also valid for nerve cells, they may shed light on the way the human brain is built: they will help to understand how the nerve cells in the brain grow their long branches, creating a complex and precise network - through which the electrical activity of the brain passes.
