Cell Communication: The Different Players and Methods

Even when we are doing something as simple as sitting, our body is not quite. It is still carrying multiple processes simultaneously. Our body never simply does one thing. There are so many interactions within a cellular level that constitutes our body as we live and breathe. Cellular communication is one of the most complex and intricate systems within our bodies. There are multiple levels of cellular communication, as well as different “messengers” between the cells.

A great example of long distance communication within our cells is how our hormones our distributed. Hormones originate from our pituitary gland within our brain. When it secretes hormones, they are then distributed to usually the blood stream, so that it has the potential to reach every cell in the body. Although there are many ways signaling can occur in these cells, it is interesting how electrical charge can play a role. In a study they modified the calcium ion levels in the anterior pituitary and even used electrical field stimulation to measure the effects on cell to cell communication (Teddy Fauquier 2001). This furthers the notion of how calcium ions and electrical charge play a pivotal role in communication. Especially in heart cells, which were found to be connected through low resistance pathways (Walmor Mello 1975). An over injection of calcium ions led to a temporary cell communication failure, as the charge became to strong, but over time communication became reestablished. So even when the heart cells became overwhelmed with the charge, their cytoplasm was able to reestablish a stable gradient for cell communication.

Besides ions and electrical charge, small molecules can be the messenger between cells. In the tongue, ATP is secreted from the taste buds and stimulate the release of the transmitter, serotonin (Yi-Jen Huang 2007). In cell communication the exact shape of the message plays a huge role. When messages are sent, they can only bond to cells that have the corresponding protein receptors. When hormones are sent throughout the body, only specific cells respond to them and follow the message to grow, or whatever else.

A representation of the Notch pathway; a more direct method of cell communication. The shape of the proteins are differentiated by the number of rectangles

Even in direct cell to cell communication the shape of receptors and proteins are important, such as in Notch signaling. It is a transmembrane receptor leads a signaling system called the Notch pathway, seen in the figure (Eric Lai 2004). The proteins in notch signaling have a specific shape that the receptor corresponds with. A similar cell to cell communication even occurs in bacteria. Quorum sensing is a way of responding to critical density in the bacteria’s environment (Everett Pesci 1999). It is a defense mechanism, that once it detects critical density, it sends an activator protein so that it can induce specific genes of a bacteria.

In cell communication there are many different players that help with this constant and complex process. From electric charge and ions, to specifically shaped proteins that can start the production of ore complex signals or even inhibit the production of a cell product. It is interesting to note how the messages can be as simple as an ion to the complexity and specificity of a protein molecule.

Sources:

1. Fauquier, T., N. Guerineau C., R. Mckinney A., K. Bauer, and P. Mollard. “Folliculostellate Cell Network: A Route for Long-distance Communication in the Anterior Pituitary.” Proceedings of the National Academy of Sciences15 (2001): 8891-896.
2. Mello, W. C De. “Effect of Intracellular Injection of Calcium and Strontium on Cell Communication in Heart.” The Journal of Physiology2 (1975): 231-45.
3. Huang, Y.-J., Y. Maruyama, G. Dvoryanchikov, E. Pereira, N. Chaudhari, and S. Roper D. “The Role of Pannexin 1 Hemichannels in ATP Release and Cell-cell Communication in Mouse Taste Buds.” Proceedings of the National Academy of Sciences15 (2007): 6436-441.
4. Lai, E. C. “Notch Signaling: Control of Cell Communication and Cell Fate.”Development5 (2004): 965-73. Web.
5. Pesci, E. C., J. Milbank B. J., J. Pearson P., S. Mcknight, A. Kende S., E. Greenberg P., and B. Iglewski H. “Quinolone Signaling in the Cell-to-cell Communication System of Pseudomonas Aeruginosa.” Proceedings of the National Academy of Sciences20 (1999): 11229-1234.